1: /*
2: ** 2001-09-15
3: **
4: ** The author disclaims copyright to this source code. In place of
5: ** a legal notice, here is a blessing:
6: **
7: ** May you do good and not evil.
8: ** May you find forgiveness for yourself and forgive others.
9: ** May you share freely, never taking more than you give.
10: **
11: *************************************************************************
12: ** This header file defines the interface that the SQLite library
13: ** presents to client programs. If a C-function, structure, datatype,
14: ** or constant definition does not appear in this file, then it is
15: ** not a published API of SQLite, is subject to change without
16: ** notice, and should not be referenced by programs that use SQLite.
17: **
18: ** Some of the definitions that are in this file are marked as
19: ** "experimental". Experimental interfaces are normally new
20: ** features recently added to SQLite. We do not anticipate changes
21: ** to experimental interfaces but reserve the right to make minor changes
22: ** if experience from use "in the wild" suggest such changes are prudent.
23: **
24: ** The official C-language API documentation for SQLite is derived
25: ** from comments in this file. This file is the authoritative source
26: ** on how SQLite interfaces are supposed to operate.
27: **
28: ** The name of this file under configuration management is "sqlite.h.in".
29: ** The makefile makes some minor changes to this file (such as inserting
30: ** the version number) and changes its name to "sqlite3.h" as
31: ** part of the build process.
32: */
33: #ifndef SQLITE3_H
34: #define SQLITE3_H
35: #include <stdarg.h> /* Needed for the definition of va_list */
36:
37: /*
38: ** Make sure we can call this stuff from C++.
39: */
40: #ifdef __cplusplus
41: extern "C" {
42: #endif
43:
44:
45: /*
46: ** Facilitate override of interface linkage and calling conventions.
47: ** Be aware that these macros may not be used within this particular
48: ** translation of the amalgamation and its associated header file.
49: **
50: ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51: ** compiler that the target identifier should have external linkage.
52: **
53: ** The SQLITE_CDECL macro is used to set the calling convention for
54: ** public functions that accept a variable number of arguments.
55: **
56: ** The SQLITE_APICALL macro is used to set the calling convention for
57: ** public functions that accept a fixed number of arguments.
58: **
59: ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60: **
61: ** The SQLITE_CALLBACK macro is used to set the calling convention for
62: ** function pointers.
63: **
64: ** The SQLITE_SYSAPI macro is used to set the calling convention for
65: ** functions provided by the operating system.
66: **
67: ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68: ** SQLITE_SYSAPI macros are used only when building for environments
69: ** that require non-default calling conventions.
70: */
71: #ifndef SQLITE_EXTERN
72: # define SQLITE_EXTERN extern
73: #endif
74: #ifndef SQLITE_API
75: # define SQLITE_API
76: #endif
77: #ifndef SQLITE_CDECL
78: # define SQLITE_CDECL
79: #endif
80: #ifndef SQLITE_APICALL
81: # define SQLITE_APICALL
82: #endif
83: #ifndef SQLITE_STDCALL
84: # define SQLITE_STDCALL SQLITE_APICALL
85: #endif
86: #ifndef SQLITE_CALLBACK
87: # define SQLITE_CALLBACK
88: #endif
89: #ifndef SQLITE_SYSAPI
90: # define SQLITE_SYSAPI
91: #endif
92:
93: /*
94: ** These no-op macros are used in front of interfaces to mark those
95: ** interfaces as either deprecated or experimental. New applications
96: ** should not use deprecated interfaces - they are supported for backwards
97: ** compatibility only. Application writers should be aware that
98: ** experimental interfaces are subject to change in point releases.
99: **
100: ** These macros used to resolve to various kinds of compiler magic that
101: ** would generate warning messages when they were used. But that
102: ** compiler magic ended up generating such a flurry of bug reports
103: ** that we have taken it all out and gone back to using simple
104: ** noop macros.
105: */
106: #define SQLITE_DEPRECATED
107: #define SQLITE_EXPERIMENTAL
108:
109: /*
110: ** Ensure these symbols were not defined by some previous header file.
111: */
112: #ifdef SQLITE_VERSION
113: # undef SQLITE_VERSION
114: #endif
115: #ifdef SQLITE_VERSION_NUMBER
116: # undef SQLITE_VERSION_NUMBER
117: #endif
118:
119: /*
120: ** CAPI3REF: Compile-Time Library Version Numbers
121: **
122: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123: ** evaluates to a string literal that is the SQLite version in the
124: ** format "X.Y.Z" where X is the major version number (always 3 for
125: ** SQLite3) and Y is the minor version number and Z is the release number.)^
126: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128: ** numbers used in [SQLITE_VERSION].)^
129: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130: ** be larger than the release from which it is derived. Either Y will
131: ** be held constant and Z will be incremented or else Y will be incremented
132: ** and Z will be reset to zero.
133: **
134: ** Since [version 3.6.18] ([dateof:3.6.18]),
135: ** SQLite source code has been stored in the
136: ** <a href="http://www.fossil-scm.org/">Fossil configuration management
137: ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138: ** a string which identifies a particular check-in of SQLite
139: ** within its configuration management system. ^The SQLITE_SOURCE_ID
140: ** string contains the date and time of the check-in (UTC) and a SHA1
141: ** or SHA3-256 hash of the entire source tree. If the source code has
142: ** been edited in any way since it was last checked in, then the last
143: ** four hexadecimal digits of the hash may be modified.
144: **
145: ** See also: [sqlite3_libversion()],
146: ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147: ** [sqlite_version()] and [sqlite_source_id()].
148: */
149: #define SQLITE_VERSION "3.43.1"
150: #define SQLITE_VERSION_NUMBER 3043001
151: #define SQLITE_SOURCE_ID "2023-09-11 12:01:27 2d3a40c05c49e1a49264912b1a05bc2143ac0e7c3df588276ce80a4cbc9bd1b0"
152:
153: /*
154: ** CAPI3REF: Run-Time Library Version Numbers
155: ** KEYWORDS: sqlite3_version sqlite3_sourceid
156: **
157: ** These interfaces provide the same information as the [SQLITE_VERSION],
158: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159: ** but are associated with the library instead of the header file. ^(Cautious
160: ** programmers might include assert() statements in their application to
161: ** verify that values returned by these interfaces match the macros in
162: ** the header, and thus ensure that the application is
163: ** compiled with matching library and header files.
164: **
165: ** <blockquote><pre>
166: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167: ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169: ** </pre></blockquote>)^
170: **
171: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172: ** macro. ^The sqlite3_libversion() function returns a pointer to the
173: ** to the sqlite3_version[] string constant. The sqlite3_libversion()
174: ** function is provided for use in DLLs since DLL users usually do not have
175: ** direct access to string constants within the DLL. ^The
176: ** sqlite3_libversion_number() function returns an integer equal to
177: ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178: ** a pointer to a string constant whose value is the same as the
179: ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180: ** using an edited copy of [the amalgamation], then the last four characters
181: ** of the hash might be different from [SQLITE_SOURCE_ID].)^
182: **
183: ** See also: [sqlite_version()] and [sqlite_source_id()].
184: */
185: SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186: SQLITE_API const char *sqlite3_libversion(void);
187: SQLITE_API const char *sqlite3_sourceid(void);
188: SQLITE_API int sqlite3_libversion_number(void);
189:
190: /*
191: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192: **
193: ** ^The sqlite3_compileoption_used() function returns 0 or 1
194: ** indicating whether the specified option was defined at
195: ** compile time. ^The SQLITE_ prefix may be omitted from the
196: ** option name passed to sqlite3_compileoption_used().
197: **
198: ** ^The sqlite3_compileoption_get() function allows iterating
199: ** over the list of options that were defined at compile time by
200: ** returning the N-th compile time option string. ^If N is out of range,
201: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202: ** prefix is omitted from any strings returned by
203: ** sqlite3_compileoption_get().
204: **
205: ** ^Support for the diagnostic functions sqlite3_compileoption_used()
206: ** and sqlite3_compileoption_get() may be omitted by specifying the
207: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208: **
209: ** See also: SQL functions [sqlite_compileoption_used()] and
210: ** [sqlite_compileoption_get()] and the [compile_options pragma].
211: */
212: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213: SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214: SQLITE_API const char *sqlite3_compileoption_get(int N);
215: #else
216: # define sqlite3_compileoption_used(X) 0
217: # define sqlite3_compileoption_get(X) ((void*)0)
218: #endif
219:
220: /*
221: ** CAPI3REF: Test To See If The Library Is Threadsafe
222: **
223: ** ^The sqlite3_threadsafe() function returns zero if and only if
224: ** SQLite was compiled with mutexing code omitted due to the
225: ** [SQLITE_THREADSAFE] compile-time option being set to 0.
226: **
227: ** SQLite can be compiled with or without mutexes. When
228: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229: ** are enabled and SQLite is threadsafe. When the
230: ** [SQLITE_THREADSAFE] macro is 0,
231: ** the mutexes are omitted. Without the mutexes, it is not safe
232: ** to use SQLite concurrently from more than one thread.
233: **
234: ** Enabling mutexes incurs a measurable performance penalty.
235: ** So if speed is of utmost importance, it makes sense to disable
236: ** the mutexes. But for maximum safety, mutexes should be enabled.
237: ** ^The default behavior is for mutexes to be enabled.
238: **
239: ** This interface can be used by an application to make sure that the
240: ** version of SQLite that it is linking against was compiled with
241: ** the desired setting of the [SQLITE_THREADSAFE] macro.
242: **
243: ** This interface only reports on the compile-time mutex setting
244: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246: ** can be fully or partially disabled using a call to [sqlite3_config()]
247: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248: ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249: ** sqlite3_threadsafe() function shows only the compile-time setting of
250: ** thread safety, not any run-time changes to that setting made by
251: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252: ** is unchanged by calls to sqlite3_config().)^
253: **
254: ** See the [threading mode] documentation for additional information.
255: */
256: SQLITE_API int sqlite3_threadsafe(void);
257:
258: /*
259: ** CAPI3REF: Database Connection Handle
260: ** KEYWORDS: {database connection} {database connections}
261: **
262: ** Each open SQLite database is represented by a pointer to an instance of
263: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266: ** and [sqlite3_close_v2()] are its destructors. There are many other
267: ** interfaces (such as
268: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269: ** [sqlite3_busy_timeout()] to name but three) that are methods on an
270: ** sqlite3 object.
271: */
272: typedef struct sqlite3 sqlite3;
273:
274: /*
275: ** CAPI3REF: 64-Bit Integer Types
276: ** KEYWORDS: sqlite_int64 sqlite_uint64
277: **
278: ** Because there is no cross-platform way to specify 64-bit integer types
279: ** SQLite includes typedefs for 64-bit signed and unsigned integers.
280: **
281: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283: ** compatibility only.
284: **
285: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287: ** sqlite3_uint64 and sqlite_uint64 types can store integer values
288: ** between 0 and +18446744073709551615 inclusive.
289: */
290: #ifdef SQLITE_INT64_TYPE
291: typedef SQLITE_INT64_TYPE sqlite_int64;
292: # ifdef SQLITE_UINT64_TYPE
293: typedef SQLITE_UINT64_TYPE sqlite_uint64;
294: # else
295: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296: # endif
297: #elif defined(_MSC_VER) || defined(__BORLANDC__)
298: typedef __int64 sqlite_int64;
299: typedef unsigned __int64 sqlite_uint64;
300: #else
301: typedef long long int sqlite_int64;
302: typedef unsigned long long int sqlite_uint64;
303: #endif
304: typedef sqlite_int64 sqlite3_int64;
305: typedef sqlite_uint64 sqlite3_uint64;
306:
307: /*
308: ** If compiling for a processor that lacks floating point support,
309: ** substitute integer for floating-point.
310: */
311: #ifdef SQLITE_OMIT_FLOATING_POINT
312: # define double sqlite3_int64
313: #endif
314:
315: /*
316: ** CAPI3REF: Closing A Database Connection
317: ** DESTRUCTOR: sqlite3
318: **
319: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320: ** for the [sqlite3] object.
321: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322: ** the [sqlite3] object is successfully destroyed and all associated
323: ** resources are deallocated.
324: **
325: ** Ideally, applications should [sqlite3_finalize | finalize] all
326: ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327: ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328: ** with the [sqlite3] object prior to attempting to close the object.
329: ** ^If the database connection is associated with unfinalized prepared
330: ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331: ** sqlite3_close() will leave the database connection open and return
332: ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333: ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334: ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335: ** connection immediately, it marks the database connection as an unusable
336: ** "zombie" and makes arrangements to automatically deallocate the database
337: ** connection after all prepared statements are finalized, all BLOB handles
338: ** are closed, and all backups have finished. The sqlite3_close_v2() interface
339: ** is intended for use with host languages that are garbage collected, and
340: ** where the order in which destructors are called is arbitrary.
341: **
342: ** ^If an [sqlite3] object is destroyed while a transaction is open,
343: ** the transaction is automatically rolled back.
344: **
345: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346: ** must be either a NULL
347: ** pointer or an [sqlite3] object pointer obtained
348: ** from [sqlite3_open()], [sqlite3_open16()], or
349: ** [sqlite3_open_v2()], and not previously closed.
350: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351: ** argument is a harmless no-op.
352: */
353: SQLITE_API int sqlite3_close(sqlite3*);
354: SQLITE_API int sqlite3_close_v2(sqlite3*);
355:
356: /*
357: ** The type for a callback function.
358: ** This is legacy and deprecated. It is included for historical
359: ** compatibility and is not documented.
360: */
361: typedef int (*sqlite3_callback)(void*,int,char**, char**);
362:
363: /*
364: ** CAPI3REF: One-Step Query Execution Interface
365: ** METHOD: sqlite3
366: **
367: ** The sqlite3_exec() interface is a convenience wrapper around
368: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369: ** that allows an application to run multiple statements of SQL
370: ** without having to use a lot of C code.
371: **
372: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373: ** semicolon-separate SQL statements passed into its 2nd argument,
374: ** in the context of the [database connection] passed in as its 1st
375: ** argument. ^If the callback function of the 3rd argument to
376: ** sqlite3_exec() is not NULL, then it is invoked for each result row
377: ** coming out of the evaluated SQL statements. ^The 4th argument to
378: ** sqlite3_exec() is relayed through to the 1st argument of each
379: ** callback invocation. ^If the callback pointer to sqlite3_exec()
380: ** is NULL, then no callback is ever invoked and result rows are
381: ** ignored.
382: **
383: ** ^If an error occurs while evaluating the SQL statements passed into
384: ** sqlite3_exec(), then execution of the current statement stops and
385: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386: ** is not NULL then any error message is written into memory obtained
387: ** from [sqlite3_malloc()] and passed back through the 5th parameter.
388: ** To avoid memory leaks, the application should invoke [sqlite3_free()]
389: ** on error message strings returned through the 5th parameter of
390: ** sqlite3_exec() after the error message string is no longer needed.
391: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393: ** NULL before returning.
394: **
395: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396: ** routine returns SQLITE_ABORT without invoking the callback again and
397: ** without running any subsequent SQL statements.
398: **
399: ** ^The 2nd argument to the sqlite3_exec() callback function is the
400: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401: ** callback is an array of pointers to strings obtained as if from
402: ** [sqlite3_column_text()], one for each column. ^If an element of a
403: ** result row is NULL then the corresponding string pointer for the
404: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405: ** sqlite3_exec() callback is an array of pointers to strings where each
406: ** entry represents the name of corresponding result column as obtained
407: ** from [sqlite3_column_name()].
408: **
409: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410: ** to an empty string, or a pointer that contains only whitespace and/or
411: ** SQL comments, then no SQL statements are evaluated and the database
412: ** is not changed.
413: **
414: ** Restrictions:
415: **
416: ** <ul>
417: ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418: ** is a valid and open [database connection].
419: ** <li> The application must not close the [database connection] specified by
420: ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421: ** <li> The application must not modify the SQL statement text passed into
422: ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423: ** </ul>
424: */
425: SQLITE_API int sqlite3_exec(
426: sqlite3*, /* An open database */
427: const char *sql, /* SQL to be evaluated */
428: int (*callback)(void*,int,char**,char**), /* Callback function */
429: void *, /* 1st argument to callback */
430: char **errmsg /* Error msg written here */
431: );
432:
433: /*
434: ** CAPI3REF: Result Codes
435: ** KEYWORDS: {result code definitions}
436: **
437: ** Many SQLite functions return an integer result code from the set shown
438: ** here in order to indicate success or failure.
439: **
440: ** New error codes may be added in future versions of SQLite.
441: **
442: ** See also: [extended result code definitions]
443: */
444: #define SQLITE_OK 0 /* Successful result */
445: /* beginning-of-error-codes */
446: #define SQLITE_ERROR 1 /* Generic error */
447: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448: #define SQLITE_PERM 3 /* Access permission denied */
449: #define SQLITE_ABORT 4 /* Callback routine requested an abort */
450: #define SQLITE_BUSY 5 /* The database file is locked */
451: #define SQLITE_LOCKED 6 /* A table in the database is locked */
452: #define SQLITE_NOMEM 7 /* A malloc() failed */
453: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458: #define SQLITE_FULL 13 /* Insertion failed because database is full */
459: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461: #define SQLITE_EMPTY 16 /* Internal use only */
462: #define SQLITE_SCHEMA 17 /* The database schema changed */
463: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465: #define SQLITE_MISMATCH 20 /* Data type mismatch */
466: #define SQLITE_MISUSE 21 /* Library used incorrectly */
467: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468: #define SQLITE_AUTH 23 /* Authorization denied */
469: #define SQLITE_FORMAT 24 /* Not used */
470: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471: #define SQLITE_NOTADB 26 /* File opened that is not a database file */
472: #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473: #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476: /* end-of-error-codes */
477:
478: /*
479: ** CAPI3REF: Extended Result Codes
480: ** KEYWORDS: {extended result code definitions}
481: **
482: ** In its default configuration, SQLite API routines return one of 30 integer
483: ** [result codes]. However, experience has shown that many of
484: ** these result codes are too coarse-grained. They do not provide as
485: ** much information about problems as programmers might like. In an effort to
486: ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487: ** and later) include
488: ** support for additional result codes that provide more detailed information
489: ** about errors. These [extended result codes] are enabled or disabled
490: ** on a per database connection basis using the
491: ** [sqlite3_extended_result_codes()] API. Or, the extended code for
492: ** the most recent error can be obtained using
493: ** [sqlite3_extended_errcode()].
494: */
495: #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496: #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497: #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521: #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522: #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523: #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524: #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525: #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526: #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527: #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528: #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529: #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530: #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531: #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
532: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
533: #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
534: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
535: #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
536: #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
537: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
538: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
539: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
540: #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
541: #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
542: #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
543: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
544: #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
545: #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
546: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
547: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
548: #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
549: #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
550: #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
551: #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
552: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
553: #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
554: #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
555: #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
556: #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
557: #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
558: #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
559: #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
560: #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
561: #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
562: #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
563: #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
564: #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
565: #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
566: #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
567: #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
568: #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
569: #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
570: #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
571: #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
572:
573: /*
574: ** CAPI3REF: Flags For File Open Operations
575: **
576: ** These bit values are intended for use in the
577: ** 3rd parameter to the [sqlite3_open_v2()] interface and
578: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
579: **
580: ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
581: ** used as the third argument to the [sqlite3_open_v2()] interface.
582: ** The other flags have historically been ignored by sqlite3_open_v2(),
583: ** though future versions of SQLite might change so that an error is
584: ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
585: ** Applications should not depend on the historical behavior.
586: **
587: ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
588: ** [sqlite3_open_v2()] does *not* cause the underlying database file
589: ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
590: ** [sqlite3_open_v2()] has historically be a no-op and might become an
591: ** error in future versions of SQLite.
592: */
593: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
594: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
595: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
596: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
597: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
598: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
599: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
600: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
601: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
602: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
603: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
604: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
605: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
606: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
607: #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
608: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
609: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
610: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
611: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
612: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
613: #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
614: #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
615:
616: /* Reserved: 0x00F00000 */
617: /* Legacy compatibility: */
618: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
619:
620:
621: /*
622: ** CAPI3REF: Device Characteristics
623: **
624: ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
625: ** object returns an integer which is a vector of these
626: ** bit values expressing I/O characteristics of the mass storage
627: ** device that holds the file that the [sqlite3_io_methods]
628: ** refers to.
629: **
630: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
631: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
632: ** mean that writes of blocks that are nnn bytes in size and
633: ** are aligned to an address which is an integer multiple of
634: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
635: ** that when data is appended to a file, the data is appended
636: ** first then the size of the file is extended, never the other
637: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
638: ** information is written to disk in the same order as calls
639: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
640: ** after reboot following a crash or power loss, the only bytes in a
641: ** file that were written at the application level might have changed
642: ** and that adjacent bytes, even bytes within the same sector are
643: ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
644: ** flag indicates that a file cannot be deleted when open. The
645: ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
646: ** read-only media and cannot be changed even by processes with
647: ** elevated privileges.
648: **
649: ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
650: ** filesystem supports doing multiple write operations atomically when those
651: ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
652: ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
653: */
654: #define SQLITE_IOCAP_ATOMIC 0x00000001
655: #define SQLITE_IOCAP_ATOMIC512 0x00000002
656: #define SQLITE_IOCAP_ATOMIC1K 0x00000004
657: #define SQLITE_IOCAP_ATOMIC2K 0x00000008
658: #define SQLITE_IOCAP_ATOMIC4K 0x00000010
659: #define SQLITE_IOCAP_ATOMIC8K 0x00000020
660: #define SQLITE_IOCAP_ATOMIC16K 0x00000040
661: #define SQLITE_IOCAP_ATOMIC32K 0x00000080
662: #define SQLITE_IOCAP_ATOMIC64K 0x00000100
663: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
664: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
665: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
666: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
667: #define SQLITE_IOCAP_IMMUTABLE 0x00002000
668: #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
669:
670: /*
671: ** CAPI3REF: File Locking Levels
672: **
673: ** SQLite uses one of these integer values as the second
674: ** argument to calls it makes to the xLock() and xUnlock() methods
675: ** of an [sqlite3_io_methods] object. These values are ordered from
676: ** lest restrictive to most restrictive.
677: **
678: ** The argument to xLock() is always SHARED or higher. The argument to
679: ** xUnlock is either SHARED or NONE.
680: */
681: #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
682: #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
683: #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
684: #define SQLITE_LOCK_PENDING 3 /* xLock() only */
685: #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
686:
687: /*
688: ** CAPI3REF: Synchronization Type Flags
689: **
690: ** When SQLite invokes the xSync() method of an
691: ** [sqlite3_io_methods] object it uses a combination of
692: ** these integer values as the second argument.
693: **
694: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
695: ** sync operation only needs to flush data to mass storage. Inode
696: ** information need not be flushed. If the lower four bits of the flag
697: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
698: ** If the lower four bits equal SQLITE_SYNC_FULL, that means
699: ** to use Mac OS X style fullsync instead of fsync().
700: **
701: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
702: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
703: ** settings. The [synchronous pragma] determines when calls to the
704: ** xSync VFS method occur and applies uniformly across all platforms.
705: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
706: ** energetic or rigorous or forceful the sync operations are and
707: ** only make a difference on Mac OSX for the default SQLite code.
708: ** (Third-party VFS implementations might also make the distinction
709: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
710: ** operating systems natively supported by SQLite, only Mac OSX
711: ** cares about the difference.)
712: */
713: #define SQLITE_SYNC_NORMAL 0x00002
714: #define SQLITE_SYNC_FULL 0x00003
715: #define SQLITE_SYNC_DATAONLY 0x00010
716:
717: /*
718: ** CAPI3REF: OS Interface Open File Handle
719: **
720: ** An [sqlite3_file] object represents an open file in the
721: ** [sqlite3_vfs | OS interface layer]. Individual OS interface
722: ** implementations will
723: ** want to subclass this object by appending additional fields
724: ** for their own use. The pMethods entry is a pointer to an
725: ** [sqlite3_io_methods] object that defines methods for performing
726: ** I/O operations on the open file.
727: */
728: typedef struct sqlite3_file sqlite3_file;
729: struct sqlite3_file {
730: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
731: };
732:
733: /*
734: ** CAPI3REF: OS Interface File Virtual Methods Object
735: **
736: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
737: ** [sqlite3_file] object (or, more commonly, a subclass of the
738: ** [sqlite3_file] object) with a pointer to an instance of this object.
739: ** This object defines the methods used to perform various operations
740: ** against the open file represented by the [sqlite3_file] object.
741: **
742: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
743: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
744: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
745: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
746: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
747: ** to NULL.
748: **
749: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
750: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
751: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
752: ** flag may be ORed in to indicate that only the data of the file
753: ** and not its inode needs to be synced.
754: **
755: ** The integer values to xLock() and xUnlock() are one of
756: ** <ul>
757: ** <li> [SQLITE_LOCK_NONE],
758: ** <li> [SQLITE_LOCK_SHARED],
759: ** <li> [SQLITE_LOCK_RESERVED],
760: ** <li> [SQLITE_LOCK_PENDING], or
761: ** <li> [SQLITE_LOCK_EXCLUSIVE].
762: ** </ul>
763: ** xLock() upgrades the database file lock. In other words, xLock() moves the
764: ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
765: ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
766: ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
767: ** requested lock, then the call to xLock() is a no-op.
768: ** xUnlock() downgrades the database file lock to either SHARED or NONE.
769: * If the lock is already at or below the requested lock state, then the call
770: ** to xUnlock() is a no-op.
771: ** The xCheckReservedLock() method checks whether any database connection,
772: ** either in this process or in some other process, is holding a RESERVED,
773: ** PENDING, or EXCLUSIVE lock on the file. It returns true
774: ** if such a lock exists and false otherwise.
775: **
776: ** The xFileControl() method is a generic interface that allows custom
777: ** VFS implementations to directly control an open file using the
778: ** [sqlite3_file_control()] interface. The second "op" argument is an
779: ** integer opcode. The third argument is a generic pointer intended to
780: ** point to a structure that may contain arguments or space in which to
781: ** write return values. Potential uses for xFileControl() might be
782: ** functions to enable blocking locks with timeouts, to change the
783: ** locking strategy (for example to use dot-file locks), to inquire
784: ** about the status of a lock, or to break stale locks. The SQLite
785: ** core reserves all opcodes less than 100 for its own use.
786: ** A [file control opcodes | list of opcodes] less than 100 is available.
787: ** Applications that define a custom xFileControl method should use opcodes
788: ** greater than 100 to avoid conflicts. VFS implementations should
789: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
790: ** recognize.
791: **
792: ** The xSectorSize() method returns the sector size of the
793: ** device that underlies the file. The sector size is the
794: ** minimum write that can be performed without disturbing
795: ** other bytes in the file. The xDeviceCharacteristics()
796: ** method returns a bit vector describing behaviors of the
797: ** underlying device:
798: **
799: ** <ul>
800: ** <li> [SQLITE_IOCAP_ATOMIC]
801: ** <li> [SQLITE_IOCAP_ATOMIC512]
802: ** <li> [SQLITE_IOCAP_ATOMIC1K]
803: ** <li> [SQLITE_IOCAP_ATOMIC2K]
804: ** <li> [SQLITE_IOCAP_ATOMIC4K]
805: ** <li> [SQLITE_IOCAP_ATOMIC8K]
806: ** <li> [SQLITE_IOCAP_ATOMIC16K]
807: ** <li> [SQLITE_IOCAP_ATOMIC32K]
808: ** <li> [SQLITE_IOCAP_ATOMIC64K]
809: ** <li> [SQLITE_IOCAP_SAFE_APPEND]
810: ** <li> [SQLITE_IOCAP_SEQUENTIAL]
811: ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
812: ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
813: ** <li> [SQLITE_IOCAP_IMMUTABLE]
814: ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
815: ** </ul>
816: **
817: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
818: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
819: ** mean that writes of blocks that are nnn bytes in size and
820: ** are aligned to an address which is an integer multiple of
821: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
822: ** that when data is appended to a file, the data is appended
823: ** first then the size of the file is extended, never the other
824: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
825: ** information is written to disk in the same order as calls
826: ** to xWrite().
827: **
828: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
829: ** in the unread portions of the buffer with zeros. A VFS that
830: ** fails to zero-fill short reads might seem to work. However,
831: ** failure to zero-fill short reads will eventually lead to
832: ** database corruption.
833: */
834: typedef struct sqlite3_io_methods sqlite3_io_methods;
835: struct sqlite3_io_methods {
836: int iVersion;
837: int (*xClose)(sqlite3_file*);
838: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
839: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
840: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
841: int (*xSync)(sqlite3_file*, int flags);
842: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
843: int (*xLock)(sqlite3_file*, int);
844: int (*xUnlock)(sqlite3_file*, int);
845: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
846: int (*xFileControl)(sqlite3_file*, int op, void *pArg);
847: int (*xSectorSize)(sqlite3_file*);
848: int (*xDeviceCharacteristics)(sqlite3_file*);
849: /* Methods above are valid for version 1 */
850: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
851: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
852: void (*xShmBarrier)(sqlite3_file*);
853: int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
854: /* Methods above are valid for version 2 */
855: int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
856: int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
857: /* Methods above are valid for version 3 */
858: /* Additional methods may be added in future releases */
859: };
860:
861: /*
862: ** CAPI3REF: Standard File Control Opcodes
863: ** KEYWORDS: {file control opcodes} {file control opcode}
864: **
865: ** These integer constants are opcodes for the xFileControl method
866: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
867: ** interface.
868: **
869: ** <ul>
870: ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
871: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
872: ** opcode causes the xFileControl method to write the current state of
873: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
874: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
875: ** into an integer that the pArg argument points to.
876: ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
877: **
878: ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
879: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
880: ** layer a hint of how large the database file will grow to be during the
881: ** current transaction. This hint is not guaranteed to be accurate but it
882: ** is often close. The underlying VFS might choose to preallocate database
883: ** file space based on this hint in order to help writes to the database
884: ** file run faster.
885: **
886: ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
887: ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
888: ** implements [sqlite3_deserialize()] to set an upper bound on the size
889: ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
890: ** If the integer pointed to is negative, then it is filled in with the
891: ** current limit. Otherwise the limit is set to the larger of the value
892: ** of the integer pointed to and the current database size. The integer
893: ** pointed to is set to the new limit.
894: **
895: ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
896: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
897: ** extends and truncates the database file in chunks of a size specified
898: ** by the user. The fourth argument to [sqlite3_file_control()] should
899: ** point to an integer (type int) containing the new chunk-size to use
900: ** for the nominated database. Allocating database file space in large
901: ** chunks (say 1MB at a time), may reduce file-system fragmentation and
902: ** improve performance on some systems.
903: **
904: ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
905: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
906: ** to the [sqlite3_file] object associated with a particular database
907: ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
908: **
909: ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
910: ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
911: ** to the [sqlite3_file] object associated with the journal file (either
912: ** the [rollback journal] or the [write-ahead log]) for a particular database
913: ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
914: **
915: ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
916: ** No longer in use.
917: **
918: ** <li>[[SQLITE_FCNTL_SYNC]]
919: ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
920: ** sent to the VFS immediately before the xSync method is invoked on a
921: ** database file descriptor. Or, if the xSync method is not invoked
922: ** because the user has configured SQLite with
923: ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
924: ** of the xSync method. In most cases, the pointer argument passed with
925: ** this file-control is NULL. However, if the database file is being synced
926: ** as part of a multi-database commit, the argument points to a nul-terminated
927: ** string containing the transactions super-journal file name. VFSes that
928: ** do not need this signal should silently ignore this opcode. Applications
929: ** should not call [sqlite3_file_control()] with this opcode as doing so may
930: ** disrupt the operation of the specialized VFSes that do require it.
931: **
932: ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
933: ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
934: ** and sent to the VFS after a transaction has been committed immediately
935: ** but before the database is unlocked. VFSes that do not need this signal
936: ** should silently ignore this opcode. Applications should not call
937: ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
938: ** operation of the specialized VFSes that do require it.
939: **
940: ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
941: ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
942: ** retry counts and intervals for certain disk I/O operations for the
943: ** windows [VFS] in order to provide robustness in the presence of
944: ** anti-virus programs. By default, the windows VFS will retry file read,
945: ** file write, and file delete operations up to 10 times, with a delay
946: ** of 25 milliseconds before the first retry and with the delay increasing
947: ** by an additional 25 milliseconds with each subsequent retry. This
948: ** opcode allows these two values (10 retries and 25 milliseconds of delay)
949: ** to be adjusted. The values are changed for all database connections
950: ** within the same process. The argument is a pointer to an array of two
951: ** integers where the first integer is the new retry count and the second
952: ** integer is the delay. If either integer is negative, then the setting
953: ** is not changed but instead the prior value of that setting is written
954: ** into the array entry, allowing the current retry settings to be
955: ** interrogated. The zDbName parameter is ignored.
956: **
957: ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
958: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
959: ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
960: ** write ahead log ([WAL file]) and shared memory
961: ** files used for transaction control
962: ** are automatically deleted when the latest connection to the database
963: ** closes. Setting persistent WAL mode causes those files to persist after
964: ** close. Persisting the files is useful when other processes that do not
965: ** have write permission on the directory containing the database file want
966: ** to read the database file, as the WAL and shared memory files must exist
967: ** in order for the database to be readable. The fourth parameter to
968: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
969: ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
970: ** WAL mode. If the integer is -1, then it is overwritten with the current
971: ** WAL persistence setting.
972: **
973: ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
974: ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
975: ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
976: ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
977: ** xDeviceCharacteristics methods. The fourth parameter to
978: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
979: ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
980: ** mode. If the integer is -1, then it is overwritten with the current
981: ** zero-damage mode setting.
982: **
983: ** <li>[[SQLITE_FCNTL_OVERWRITE]]
984: ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
985: ** a write transaction to indicate that, unless it is rolled back for some
986: ** reason, the entire database file will be overwritten by the current
987: ** transaction. This is used by VACUUM operations.
988: **
989: ** <li>[[SQLITE_FCNTL_VFSNAME]]
990: ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
991: ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
992: ** final bottom-level VFS are written into memory obtained from
993: ** [sqlite3_malloc()] and the result is stored in the char* variable
994: ** that the fourth parameter of [sqlite3_file_control()] points to.
995: ** The caller is responsible for freeing the memory when done. As with
996: ** all file-control actions, there is no guarantee that this will actually
997: ** do anything. Callers should initialize the char* variable to a NULL
998: ** pointer in case this file-control is not implemented. This file-control
999: ** is intended for diagnostic use only.
1000: **
1001: ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1002: ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1003: ** [VFSes] currently in use. ^(The argument X in
1004: ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1005: ** of type "[sqlite3_vfs] **". This opcodes will set *X
1006: ** to a pointer to the top-level VFS.)^
1007: ** ^When there are multiple VFS shims in the stack, this opcode finds the
1008: ** upper-most shim only.
1009: **
1010: ** <li>[[SQLITE_FCNTL_PRAGMA]]
1011: ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1012: ** file control is sent to the open [sqlite3_file] object corresponding
1013: ** to the database file to which the pragma statement refers. ^The argument
1014: ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1015: ** pointers to strings (char**) in which the second element of the array
1016: ** is the name of the pragma and the third element is the argument to the
1017: ** pragma or NULL if the pragma has no argument. ^The handler for an
1018: ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1019: ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1020: ** or the equivalent and that string will become the result of the pragma or
1021: ** the error message if the pragma fails. ^If the
1022: ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1023: ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1024: ** file control returns [SQLITE_OK], then the parser assumes that the
1025: ** VFS has handled the PRAGMA itself and the parser generates a no-op
1026: ** prepared statement if result string is NULL, or that returns a copy
1027: ** of the result string if the string is non-NULL.
1028: ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1029: ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1030: ** that the VFS encountered an error while handling the [PRAGMA] and the
1031: ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1032: ** file control occurs at the beginning of pragma statement analysis and so
1033: ** it is able to override built-in [PRAGMA] statements.
1034: **
1035: ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1036: ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1037: ** file-control may be invoked by SQLite on the database file handle
1038: ** shortly after it is opened in order to provide a custom VFS with access
1039: ** to the connection's busy-handler callback. The argument is of type (void**)
1040: ** - an array of two (void *) values. The first (void *) actually points
1041: ** to a function of type (int (*)(void *)). In order to invoke the connection's
1042: ** busy-handler, this function should be invoked with the second (void *) in
1043: ** the array as the only argument. If it returns non-zero, then the operation
1044: ** should be retried. If it returns zero, the custom VFS should abandon the
1045: ** current operation.
1046: **
1047: ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1048: ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1049: ** to have SQLite generate a
1050: ** temporary filename using the same algorithm that is followed to generate
1051: ** temporary filenames for TEMP tables and other internal uses. The
1052: ** argument should be a char** which will be filled with the filename
1053: ** written into memory obtained from [sqlite3_malloc()]. The caller should
1054: ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1055: **
1056: ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1057: ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1058: ** maximum number of bytes that will be used for memory-mapped I/O.
1059: ** The argument is a pointer to a value of type sqlite3_int64 that
1060: ** is an advisory maximum number of bytes in the file to memory map. The
1061: ** pointer is overwritten with the old value. The limit is not changed if
1062: ** the value originally pointed to is negative, and so the current limit
1063: ** can be queried by passing in a pointer to a negative number. This
1064: ** file-control is used internally to implement [PRAGMA mmap_size].
1065: **
1066: ** <li>[[SQLITE_FCNTL_TRACE]]
1067: ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1068: ** to the VFS about what the higher layers of the SQLite stack are doing.
1069: ** This file control is used by some VFS activity tracing [shims].
1070: ** The argument is a zero-terminated string. Higher layers in the
1071: ** SQLite stack may generate instances of this file control if
1072: ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1073: **
1074: ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1075: ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1076: ** pointer to an integer and it writes a boolean into that integer depending
1077: ** on whether or not the file has been renamed, moved, or deleted since it
1078: ** was first opened.
1079: **
1080: ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1081: ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1082: ** underlying native file handle associated with a file handle. This file
1083: ** control interprets its argument as a pointer to a native file handle and
1084: ** writes the resulting value there.
1085: **
1086: ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1087: ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1088: ** opcode causes the xFileControl method to swap the file handle with the one
1089: ** pointed to by the pArg argument. This capability is used during testing
1090: ** and only needs to be supported when SQLITE_TEST is defined.
1091: **
1092: ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1093: ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1094: ** be advantageous to block on the next WAL lock if the lock is not immediately
1095: ** available. The WAL subsystem issues this signal during rare
1096: ** circumstances in order to fix a problem with priority inversion.
1097: ** Applications should <em>not</em> use this file-control.
1098: **
1099: ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1100: ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1101: ** VFS should return SQLITE_NOTFOUND for this opcode.
1102: **
1103: ** <li>[[SQLITE_FCNTL_RBU]]
1104: ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1105: ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1106: ** this opcode.
1107: **
1108: ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1109: ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1110: ** the file descriptor is placed in "batch write mode", which
1111: ** means all subsequent write operations will be deferred and done
1112: ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1113: ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1114: ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1115: ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1116: ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1117: ** no VFS interface calls on the same [sqlite3_file] file descriptor
1118: ** except for calls to the xWrite method and the xFileControl method
1119: ** with [SQLITE_FCNTL_SIZE_HINT].
1120: **
1121: ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1122: ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1123: ** operations since the previous successful call to
1124: ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1125: ** This file control returns [SQLITE_OK] if and only if the writes were
1126: ** all performed successfully and have been committed to persistent storage.
1127: ** ^Regardless of whether or not it is successful, this file control takes
1128: ** the file descriptor out of batch write mode so that all subsequent
1129: ** write operations are independent.
1130: ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1131: ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1132: **
1133: ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1134: ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1135: ** operations since the previous successful call to
1136: ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1137: ** ^This file control takes the file descriptor out of batch write mode
1138: ** so that all subsequent write operations are independent.
1139: ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1140: ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1141: **
1142: ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1143: ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1144: ** to block for up to M milliseconds before failing when attempting to
1145: ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1146: ** The parameter is a pointer to a 32-bit signed integer that contains
1147: ** the value that M is to be set to. Before returning, the 32-bit signed
1148: ** integer is overwritten with the previous value of M.
1149: **
1150: ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1151: ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1152: ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1153: ** The "data version" for the pager is written into the pointer. The
1154: ** "data version" changes whenever any change occurs to the corresponding
1155: ** database file, either through SQL statements on the same database
1156: ** connection or through transactions committed by separate database
1157: ** connections possibly in other processes. The [sqlite3_total_changes()]
1158: ** interface can be used to find if any database on the connection has changed,
1159: ** but that interface responds to changes on TEMP as well as MAIN and does
1160: ** not provide a mechanism to detect changes to MAIN only. Also, the
1161: ** [sqlite3_total_changes()] interface responds to internal changes only and
1162: ** omits changes made by other database connections. The
1163: ** [PRAGMA data_version] command provides a mechanism to detect changes to
1164: ** a single attached database that occur due to other database connections,
1165: ** but omits changes implemented by the database connection on which it is
1166: ** called. This file control is the only mechanism to detect changes that
1167: ** happen either internally or externally and that are associated with
1168: ** a particular attached database.
1169: **
1170: ** <li>[[SQLITE_FCNTL_CKPT_START]]
1171: ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1172: ** in wal mode before the client starts to copy pages from the wal
1173: ** file to the database file.
1174: **
1175: ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1176: ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1177: ** in wal mode after the client has finished copying pages from the wal
1178: ** file to the database file, but before the *-shm file is updated to
1179: ** record the fact that the pages have been checkpointed.
1180: **
1181: ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1182: ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1183: ** whether or not there is a database client in another process with a wal-mode
1184: ** transaction open on the database or not. It is only available on unix.The
1185: ** (void*) argument passed with this file-control should be a pointer to a
1186: ** value of type (int). The integer value is set to 1 if the database is a wal
1187: ** mode database and there exists at least one client in another process that
1188: ** currently has an SQL transaction open on the database. It is set to 0 if
1189: ** the database is not a wal-mode db, or if there is no such connection in any
1190: ** other process. This opcode cannot be used to detect transactions opened
1191: ** by clients within the current process, only within other processes.
1192: **
1193: ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1194: ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1195: ** [checksum VFS shim] only.
1196: **
1197: ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1198: ** If there is currently no transaction open on the database, and the
1199: ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1200: ** purges the contents of the in-memory page cache. If there is an open
1201: ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1202: ** </ul>
1203: */
1204: #define SQLITE_FCNTL_LOCKSTATE 1
1205: #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1206: #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1207: #define SQLITE_FCNTL_LAST_ERRNO 4
1208: #define SQLITE_FCNTL_SIZE_HINT 5
1209: #define SQLITE_FCNTL_CHUNK_SIZE 6
1210: #define SQLITE_FCNTL_FILE_POINTER 7
1211: #define SQLITE_FCNTL_SYNC_OMITTED 8
1212: #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1213: #define SQLITE_FCNTL_PERSIST_WAL 10
1214: #define SQLITE_FCNTL_OVERWRITE 11
1215: #define SQLITE_FCNTL_VFSNAME 12
1216: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1217: #define SQLITE_FCNTL_PRAGMA 14
1218: #define SQLITE_FCNTL_BUSYHANDLER 15
1219: #define SQLITE_FCNTL_TEMPFILENAME 16
1220: #define SQLITE_FCNTL_MMAP_SIZE 18
1221: #define SQLITE_FCNTL_TRACE 19
1222: #define SQLITE_FCNTL_HAS_MOVED 20
1223: #define SQLITE_FCNTL_SYNC 21
1224: #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1225: #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1226: #define SQLITE_FCNTL_WAL_BLOCK 24
1227: #define SQLITE_FCNTL_ZIPVFS 25
1228: #define SQLITE_FCNTL_RBU 26
1229: #define SQLITE_FCNTL_VFS_POINTER 27
1230: #define SQLITE_FCNTL_JOURNAL_POINTER 28
1231: #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1232: #define SQLITE_FCNTL_PDB 30
1233: #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1234: #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1235: #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1236: #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1237: #define SQLITE_FCNTL_DATA_VERSION 35
1238: #define SQLITE_FCNTL_SIZE_LIMIT 36
1239: #define SQLITE_FCNTL_CKPT_DONE 37
1240: #define SQLITE_FCNTL_RESERVE_BYTES 38
1241: #define SQLITE_FCNTL_CKPT_START 39
1242: #define SQLITE_FCNTL_EXTERNAL_READER 40
1243: #define SQLITE_FCNTL_CKSM_FILE 41
1244: #define SQLITE_FCNTL_RESET_CACHE 42
1245:
1246: /* deprecated names */
1247: #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1248: #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1249: #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1250:
1251:
1252: /*
1253: ** CAPI3REF: Mutex Handle
1254: **
1255: ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1256: ** abstract type for a mutex object. The SQLite core never looks
1257: ** at the internal representation of an [sqlite3_mutex]. It only
1258: ** deals with pointers to the [sqlite3_mutex] object.
1259: **
1260: ** Mutexes are created using [sqlite3_mutex_alloc()].
1261: */
1262: typedef struct sqlite3_mutex sqlite3_mutex;
1263:
1264: /*
1265: ** CAPI3REF: Loadable Extension Thunk
1266: **
1267: ** A pointer to the opaque sqlite3_api_routines structure is passed as
1268: ** the third parameter to entry points of [loadable extensions]. This
1269: ** structure must be typedefed in order to work around compiler warnings
1270: ** on some platforms.
1271: */
1272: typedef struct sqlite3_api_routines sqlite3_api_routines;
1273:
1274: /*
1275: ** CAPI3REF: File Name
1276: **
1277: ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1278: ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1279: ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1280: ** may also be passed to special APIs such as:
1281: **
1282: ** <ul>
1283: ** <li> sqlite3_filename_database()
1284: ** <li> sqlite3_filename_journal()
1285: ** <li> sqlite3_filename_wal()
1286: ** <li> sqlite3_uri_parameter()
1287: ** <li> sqlite3_uri_boolean()
1288: ** <li> sqlite3_uri_int64()
1289: ** <li> sqlite3_uri_key()
1290: ** </ul>
1291: */
1292: typedef const char *sqlite3_filename;
1293:
1294: /*
1295: ** CAPI3REF: OS Interface Object
1296: **
1297: ** An instance of the sqlite3_vfs object defines the interface between
1298: ** the SQLite core and the underlying operating system. The "vfs"
1299: ** in the name of the object stands for "virtual file system". See
1300: ** the [VFS | VFS documentation] for further information.
1301: **
1302: ** The VFS interface is sometimes extended by adding new methods onto
1303: ** the end. Each time such an extension occurs, the iVersion field
1304: ** is incremented. The iVersion value started out as 1 in
1305: ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1306: ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1307: ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1308: ** may be appended to the sqlite3_vfs object and the iVersion value
1309: ** may increase again in future versions of SQLite.
1310: ** Note that due to an oversight, the structure
1311: ** of the sqlite3_vfs object changed in the transition from
1312: ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1313: ** and yet the iVersion field was not increased.
1314: **
1315: ** The szOsFile field is the size of the subclassed [sqlite3_file]
1316: ** structure used by this VFS. mxPathname is the maximum length of
1317: ** a pathname in this VFS.
1318: **
1319: ** Registered sqlite3_vfs objects are kept on a linked list formed by
1320: ** the pNext pointer. The [sqlite3_vfs_register()]
1321: ** and [sqlite3_vfs_unregister()] interfaces manage this list
1322: ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1323: ** searches the list. Neither the application code nor the VFS
1324: ** implementation should use the pNext pointer.
1325: **
1326: ** The pNext field is the only field in the sqlite3_vfs
1327: ** structure that SQLite will ever modify. SQLite will only access
1328: ** or modify this field while holding a particular static mutex.
1329: ** The application should never modify anything within the sqlite3_vfs
1330: ** object once the object has been registered.
1331: **
1332: ** The zName field holds the name of the VFS module. The name must
1333: ** be unique across all VFS modules.
1334: **
1335: ** [[sqlite3_vfs.xOpen]]
1336: ** ^SQLite guarantees that the zFilename parameter to xOpen
1337: ** is either a NULL pointer or string obtained
1338: ** from xFullPathname() with an optional suffix added.
1339: ** ^If a suffix is added to the zFilename parameter, it will
1340: ** consist of a single "-" character followed by no more than
1341: ** 11 alphanumeric and/or "-" characters.
1342: ** ^SQLite further guarantees that
1343: ** the string will be valid and unchanged until xClose() is
1344: ** called. Because of the previous sentence,
1345: ** the [sqlite3_file] can safely store a pointer to the
1346: ** filename if it needs to remember the filename for some reason.
1347: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1348: ** must invent its own temporary name for the file. ^Whenever the
1349: ** xFilename parameter is NULL it will also be the case that the
1350: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1351: **
1352: ** The flags argument to xOpen() includes all bits set in
1353: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1354: ** or [sqlite3_open16()] is used, then flags includes at least
1355: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1356: ** If xOpen() opens a file read-only then it sets *pOutFlags to
1357: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1358: **
1359: ** ^(SQLite will also add one of the following flags to the xOpen()
1360: ** call, depending on the object being opened:
1361: **
1362: ** <ul>
1363: ** <li> [SQLITE_OPEN_MAIN_DB]
1364: ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1365: ** <li> [SQLITE_OPEN_TEMP_DB]
1366: ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1367: ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1368: ** <li> [SQLITE_OPEN_SUBJOURNAL]
1369: ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1370: ** <li> [SQLITE_OPEN_WAL]
1371: ** </ul>)^
1372: **
1373: ** The file I/O implementation can use the object type flags to
1374: ** change the way it deals with files. For example, an application
1375: ** that does not care about crash recovery or rollback might make
1376: ** the open of a journal file a no-op. Writes to this journal would
1377: ** also be no-ops, and any attempt to read the journal would return
1378: ** SQLITE_IOERR. Or the implementation might recognize that a database
1379: ** file will be doing page-aligned sector reads and writes in a random
1380: ** order and set up its I/O subsystem accordingly.
1381: **
1382: ** SQLite might also add one of the following flags to the xOpen method:
1383: **
1384: ** <ul>
1385: ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1386: ** <li> [SQLITE_OPEN_EXCLUSIVE]
1387: ** </ul>
1388: **
1389: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1390: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1391: ** will be set for TEMP databases and their journals, transient
1392: ** databases, and subjournals.
1393: **
1394: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1395: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1396: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1397: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1398: ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1399: ** be created, and that it is an error if it already exists.
1400: ** It is <i>not</i> used to indicate the file should be opened
1401: ** for exclusive access.
1402: **
1403: ** ^At least szOsFile bytes of memory are allocated by SQLite
1404: ** to hold the [sqlite3_file] structure passed as the third
1405: ** argument to xOpen. The xOpen method does not have to
1406: ** allocate the structure; it should just fill it in. Note that
1407: ** the xOpen method must set the sqlite3_file.pMethods to either
1408: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1409: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1410: ** element will be valid after xOpen returns regardless of the success
1411: ** or failure of the xOpen call.
1412: **
1413: ** [[sqlite3_vfs.xAccess]]
1414: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1415: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1416: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1417: ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1418: ** flag is never actually used and is not implemented in the built-in
1419: ** VFSes of SQLite. The file is named by the second argument and can be a
1420: ** directory. The xAccess method returns [SQLITE_OK] on success or some
1421: ** non-zero error code if there is an I/O error or if the name of
1422: ** the file given in the second argument is illegal. If SQLITE_OK
1423: ** is returned, then non-zero or zero is written into *pResOut to indicate
1424: ** whether or not the file is accessible.
1425: **
1426: ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1427: ** output buffer xFullPathname. The exact size of the output buffer
1428: ** is also passed as a parameter to both methods. If the output buffer
1429: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1430: ** handled as a fatal error by SQLite, vfs implementations should endeavor
1431: ** to prevent this by setting mxPathname to a sufficiently large value.
1432: **
1433: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1434: ** interfaces are not strictly a part of the filesystem, but they are
1435: ** included in the VFS structure for completeness.
1436: ** The xRandomness() function attempts to return nBytes bytes
1437: ** of good-quality randomness into zOut. The return value is
1438: ** the actual number of bytes of randomness obtained.
1439: ** The xSleep() method causes the calling thread to sleep for at
1440: ** least the number of microseconds given. ^The xCurrentTime()
1441: ** method returns a Julian Day Number for the current date and time as
1442: ** a floating point value.
1443: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1444: ** Day Number multiplied by 86400000 (the number of milliseconds in
1445: ** a 24-hour day).
1446: ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1447: ** date and time if that method is available (if iVersion is 2 or
1448: ** greater and the function pointer is not NULL) and will fall back
1449: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1450: **
1451: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1452: ** are not used by the SQLite core. These optional interfaces are provided
1453: ** by some VFSes to facilitate testing of the VFS code. By overriding
1454: ** system calls with functions under its control, a test program can
1455: ** simulate faults and error conditions that would otherwise be difficult
1456: ** or impossible to induce. The set of system calls that can be overridden
1457: ** varies from one VFS to another, and from one version of the same VFS to the
1458: ** next. Applications that use these interfaces must be prepared for any
1459: ** or all of these interfaces to be NULL or for their behavior to change
1460: ** from one release to the next. Applications must not attempt to access
1461: ** any of these methods if the iVersion of the VFS is less than 3.
1462: */
1463: typedef struct sqlite3_vfs sqlite3_vfs;
1464: typedef void (*sqlite3_syscall_ptr)(void);
1465: struct sqlite3_vfs {
1466: int iVersion; /* Structure version number (currently 3) */
1467: int szOsFile; /* Size of subclassed sqlite3_file */
1468: int mxPathname; /* Maximum file pathname length */
1469: sqlite3_vfs *pNext; /* Next registered VFS */
1470: const char *zName; /* Name of this virtual file system */
1471: void *pAppData; /* Pointer to application-specific data */
1472: int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1473: int flags, int *pOutFlags);
1474: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1475: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1476: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1477: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1478: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1479: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1480: void (*xDlClose)(sqlite3_vfs*, void*);
1481: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1482: int (*xSleep)(sqlite3_vfs*, int microseconds);
1483: int (*xCurrentTime)(sqlite3_vfs*, double*);
1484: int (*xGetLastError)(sqlite3_vfs*, int, char *);
1485: /*
1486: ** The methods above are in version 1 of the sqlite_vfs object
1487: ** definition. Those that follow are added in version 2 or later
1488: */
1489: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1490: /*
1491: ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1492: ** Those below are for version 3 and greater.
1493: */
1494: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1495: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1496: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1497: /*
1498: ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1499: ** New fields may be appended in future versions. The iVersion
1500: ** value will increment whenever this happens.
1501: */
1502: };
1503:
1504: /*
1505: ** CAPI3REF: Flags for the xAccess VFS method
1506: **
1507: ** These integer constants can be used as the third parameter to
1508: ** the xAccess method of an [sqlite3_vfs] object. They determine
1509: ** what kind of permissions the xAccess method is looking for.
1510: ** With SQLITE_ACCESS_EXISTS, the xAccess method
1511: ** simply checks whether the file exists.
1512: ** With SQLITE_ACCESS_READWRITE, the xAccess method
1513: ** checks whether the named directory is both readable and writable
1514: ** (in other words, if files can be added, removed, and renamed within
1515: ** the directory).
1516: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1517: ** [temp_store_directory pragma], though this could change in a future
1518: ** release of SQLite.
1519: ** With SQLITE_ACCESS_READ, the xAccess method
1520: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1521: ** currently unused, though it might be used in a future release of
1522: ** SQLite.
1523: */
1524: #define SQLITE_ACCESS_EXISTS 0
1525: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1526: #define SQLITE_ACCESS_READ 2 /* Unused */
1527:
1528: /*
1529: ** CAPI3REF: Flags for the xShmLock VFS method
1530: **
1531: ** These integer constants define the various locking operations
1532: ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1533: ** following are the only legal combinations of flags to the
1534: ** xShmLock method:
1535: **
1536: ** <ul>
1537: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1538: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1539: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1540: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1541: ** </ul>
1542: **
1543: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1544: ** was given on the corresponding lock.
1545: **
1546: ** The xShmLock method can transition between unlocked and SHARED or
1547: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1548: ** and EXCLUSIVE.
1549: */
1550: #define SQLITE_SHM_UNLOCK 1
1551: #define SQLITE_SHM_LOCK 2
1552: #define SQLITE_SHM_SHARED 4
1553: #define SQLITE_SHM_EXCLUSIVE 8
1554:
1555: /*
1556: ** CAPI3REF: Maximum xShmLock index
1557: **
1558: ** The xShmLock method on [sqlite3_io_methods] may use values
1559: ** between 0 and this upper bound as its "offset" argument.
1560: ** The SQLite core will never attempt to acquire or release a
1561: ** lock outside of this range
1562: */
1563: #define SQLITE_SHM_NLOCK 8
1564:
1565:
1566: /*
1567: ** CAPI3REF: Initialize The SQLite Library
1568: **
1569: ** ^The sqlite3_initialize() routine initializes the
1570: ** SQLite library. ^The sqlite3_shutdown() routine
1571: ** deallocates any resources that were allocated by sqlite3_initialize().
1572: ** These routines are designed to aid in process initialization and
1573: ** shutdown on embedded systems. Workstation applications using
1574: ** SQLite normally do not need to invoke either of these routines.
1575: **
1576: ** A call to sqlite3_initialize() is an "effective" call if it is
1577: ** the first time sqlite3_initialize() is invoked during the lifetime of
1578: ** the process, or if it is the first time sqlite3_initialize() is invoked
1579: ** following a call to sqlite3_shutdown(). ^(Only an effective call
1580: ** of sqlite3_initialize() does any initialization. All other calls
1581: ** are harmless no-ops.)^
1582: **
1583: ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1584: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1585: ** an effective call to sqlite3_shutdown() does any deinitialization.
1586: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1587: **
1588: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1589: ** is not. The sqlite3_shutdown() interface must only be called from a
1590: ** single thread. All open [database connections] must be closed and all
1591: ** other SQLite resources must be deallocated prior to invoking
1592: ** sqlite3_shutdown().
1593: **
1594: ** Among other things, ^sqlite3_initialize() will invoke
1595: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1596: ** will invoke sqlite3_os_end().
1597: **
1598: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1599: ** ^If for some reason, sqlite3_initialize() is unable to initialize
1600: ** the library (perhaps it is unable to allocate a needed resource such
1601: ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1602: **
1603: ** ^The sqlite3_initialize() routine is called internally by many other
1604: ** SQLite interfaces so that an application usually does not need to
1605: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1606: ** calls sqlite3_initialize() so the SQLite library will be automatically
1607: ** initialized when [sqlite3_open()] is called if it has not be initialized
1608: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1609: ** compile-time option, then the automatic calls to sqlite3_initialize()
1610: ** are omitted and the application must call sqlite3_initialize() directly
1611: ** prior to using any other SQLite interface. For maximum portability,
1612: ** it is recommended that applications always invoke sqlite3_initialize()
1613: ** directly prior to using any other SQLite interface. Future releases
1614: ** of SQLite may require this. In other words, the behavior exhibited
1615: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1616: ** default behavior in some future release of SQLite.
1617: **
1618: ** The sqlite3_os_init() routine does operating-system specific
1619: ** initialization of the SQLite library. The sqlite3_os_end()
1620: ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1621: ** performed by these routines include allocation or deallocation
1622: ** of static resources, initialization of global variables,
1623: ** setting up a default [sqlite3_vfs] module, or setting up
1624: ** a default configuration using [sqlite3_config()].
1625: **
1626: ** The application should never invoke either sqlite3_os_init()
1627: ** or sqlite3_os_end() directly. The application should only invoke
1628: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1629: ** interface is called automatically by sqlite3_initialize() and
1630: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1631: ** implementations for sqlite3_os_init() and sqlite3_os_end()
1632: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1633: ** When [custom builds | built for other platforms]
1634: ** (using the [SQLITE_OS_OTHER=1] compile-time
1635: ** option) the application must supply a suitable implementation for
1636: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1637: ** implementation of sqlite3_os_init() or sqlite3_os_end()
1638: ** must return [SQLITE_OK] on success and some other [error code] upon
1639: ** failure.
1640: */
1641: SQLITE_API int sqlite3_initialize(void);
1642: SQLITE_API int sqlite3_shutdown(void);
1643: SQLITE_API int sqlite3_os_init(void);
1644: SQLITE_API int sqlite3_os_end(void);
1645:
1646: /*
1647: ** CAPI3REF: Configuring The SQLite Library
1648: **
1649: ** The sqlite3_config() interface is used to make global configuration
1650: ** changes to SQLite in order to tune SQLite to the specific needs of
1651: ** the application. The default configuration is recommended for most
1652: ** applications and so this routine is usually not necessary. It is
1653: ** provided to support rare applications with unusual needs.
1654: **
1655: ** <b>The sqlite3_config() interface is not threadsafe. The application
1656: ** must ensure that no other SQLite interfaces are invoked by other
1657: ** threads while sqlite3_config() is running.</b>
1658: **
1659: ** The first argument to sqlite3_config() is an integer
1660: ** [configuration option] that determines
1661: ** what property of SQLite is to be configured. Subsequent arguments
1662: ** vary depending on the [configuration option]
1663: ** in the first argument.
1664: **
1665: ** For most configuration options, the sqlite3_config() interface
1666: ** may only be invoked prior to library initialization using
1667: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1668: ** The exceptional configuration options that may be invoked at any time
1669: ** are called "anytime configuration options".
1670: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1671: ** [sqlite3_shutdown()] with a first argument that is not an anytime
1672: ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1673: ** Note, however, that ^sqlite3_config() can be called as part of the
1674: ** implementation of an application-defined [sqlite3_os_init()].
1675: **
1676: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1677: ** ^If the option is unknown or SQLite is unable to set the option
1678: ** then this routine returns a non-zero [error code].
1679: */
1680: SQLITE_API int sqlite3_config(int, ...);
1681:
1682: /*
1683: ** CAPI3REF: Configure database connections
1684: ** METHOD: sqlite3
1685: **
1686: ** The sqlite3_db_config() interface is used to make configuration
1687: ** changes to a [database connection]. The interface is similar to
1688: ** [sqlite3_config()] except that the changes apply to a single
1689: ** [database connection] (specified in the first argument).
1690: **
1691: ** The second argument to sqlite3_db_config(D,V,...) is the
1692: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1693: ** that indicates what aspect of the [database connection] is being configured.
1694: ** Subsequent arguments vary depending on the configuration verb.
1695: **
1696: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1697: ** the call is considered successful.
1698: */
1699: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1700:
1701: /*
1702: ** CAPI3REF: Memory Allocation Routines
1703: **
1704: ** An instance of this object defines the interface between SQLite
1705: ** and low-level memory allocation routines.
1706: **
1707: ** This object is used in only one place in the SQLite interface.
1708: ** A pointer to an instance of this object is the argument to
1709: ** [sqlite3_config()] when the configuration option is
1710: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1711: ** By creating an instance of this object
1712: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1713: ** during configuration, an application can specify an alternative
1714: ** memory allocation subsystem for SQLite to use for all of its
1715: ** dynamic memory needs.
1716: **
1717: ** Note that SQLite comes with several [built-in memory allocators]
1718: ** that are perfectly adequate for the overwhelming majority of applications
1719: ** and that this object is only useful to a tiny minority of applications
1720: ** with specialized memory allocation requirements. This object is
1721: ** also used during testing of SQLite in order to specify an alternative
1722: ** memory allocator that simulates memory out-of-memory conditions in
1723: ** order to verify that SQLite recovers gracefully from such
1724: ** conditions.
1725: **
1726: ** The xMalloc, xRealloc, and xFree methods must work like the
1727: ** malloc(), realloc() and free() functions from the standard C library.
1728: ** ^SQLite guarantees that the second argument to
1729: ** xRealloc is always a value returned by a prior call to xRoundup.
1730: **
1731: ** xSize should return the allocated size of a memory allocation
1732: ** previously obtained from xMalloc or xRealloc. The allocated size
1733: ** is always at least as big as the requested size but may be larger.
1734: **
1735: ** The xRoundup method returns what would be the allocated size of
1736: ** a memory allocation given a particular requested size. Most memory
1737: ** allocators round up memory allocations at least to the next multiple
1738: ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1739: ** Every memory allocation request coming in through [sqlite3_malloc()]
1740: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1741: ** that causes the corresponding memory allocation to fail.
1742: **
1743: ** The xInit method initializes the memory allocator. For example,
1744: ** it might allocate any required mutexes or initialize internal data
1745: ** structures. The xShutdown method is invoked (indirectly) by
1746: ** [sqlite3_shutdown()] and should deallocate any resources acquired
1747: ** by xInit. The pAppData pointer is used as the only parameter to
1748: ** xInit and xShutdown.
1749: **
1750: ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1751: ** the xInit method, so the xInit method need not be threadsafe. The
1752: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1753: ** not need to be threadsafe either. For all other methods, SQLite
1754: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1755: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1756: ** it is by default) and so the methods are automatically serialized.
1757: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1758: ** methods must be threadsafe or else make their own arrangements for
1759: ** serialization.
1760: **
1761: ** SQLite will never invoke xInit() more than once without an intervening
1762: ** call to xShutdown().
1763: */
1764: typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1765: struct sqlite3_mem_methods {
1766: void *(*xMalloc)(int); /* Memory allocation function */
1767: void (*xFree)(void*); /* Free a prior allocation */
1768: void *(*xRealloc)(void*,int); /* Resize an allocation */
1769: int (*xSize)(void*); /* Return the size of an allocation */
1770: int (*xRoundup)(int); /* Round up request size to allocation size */
1771: int (*xInit)(void*); /* Initialize the memory allocator */
1772: void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1773: void *pAppData; /* Argument to xInit() and xShutdown() */
1774: };
1775:
1776: /*
1777: ** CAPI3REF: Configuration Options
1778: ** KEYWORDS: {configuration option}
1779: **
1780: ** These constants are the available integer configuration options that
1781: ** can be passed as the first argument to the [sqlite3_config()] interface.
1782: **
1783: ** Most of the configuration options for sqlite3_config()
1784: ** will only work if invoked prior to [sqlite3_initialize()] or after
1785: ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1786: ** "anytime configuration options".
1787: ** ^Calling [sqlite3_config()] with a first argument that is not an
1788: ** anytime configuration option in between calls to [sqlite3_initialize()] and
1789: ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1790: **
1791: ** The set of anytime configuration options can change (by insertions
1792: ** and/or deletions) from one release of SQLite to the next.
1793: ** As of SQLite version 3.42.0, the complete set of anytime configuration
1794: ** options is:
1795: ** <ul>
1796: ** <li> SQLITE_CONFIG_LOG
1797: ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1798: ** </ul>
1799: **
1800: ** New configuration options may be added in future releases of SQLite.
1801: ** Existing configuration options might be discontinued. Applications
1802: ** should check the return code from [sqlite3_config()] to make sure that
1803: ** the call worked. The [sqlite3_config()] interface will return a
1804: ** non-zero [error code] if a discontinued or unsupported configuration option
1805: ** is invoked.
1806: **
1807: ** <dl>
1808: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1809: ** <dd>There are no arguments to this option. ^This option sets the
1810: ** [threading mode] to Single-thread. In other words, it disables
1811: ** all mutexing and puts SQLite into a mode where it can only be used
1812: ** by a single thread. ^If SQLite is compiled with
1813: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1814: ** it is not possible to change the [threading mode] from its default
1815: ** value of Single-thread and so [sqlite3_config()] will return
1816: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1817: ** configuration option.</dd>
1818: **
1819: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1820: ** <dd>There are no arguments to this option. ^This option sets the
1821: ** [threading mode] to Multi-thread. In other words, it disables
1822: ** mutexing on [database connection] and [prepared statement] objects.
1823: ** The application is responsible for serializing access to
1824: ** [database connections] and [prepared statements]. But other mutexes
1825: ** are enabled so that SQLite will be safe to use in a multi-threaded
1826: ** environment as long as no two threads attempt to use the same
1827: ** [database connection] at the same time. ^If SQLite is compiled with
1828: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1829: ** it is not possible to set the Multi-thread [threading mode] and
1830: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1831: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1832: **
1833: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1834: ** <dd>There are no arguments to this option. ^This option sets the
1835: ** [threading mode] to Serialized. In other words, this option enables
1836: ** all mutexes including the recursive
1837: ** mutexes on [database connection] and [prepared statement] objects.
1838: ** In this mode (which is the default when SQLite is compiled with
1839: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1840: ** to [database connections] and [prepared statements] so that the
1841: ** application is free to use the same [database connection] or the
1842: ** same [prepared statement] in different threads at the same time.
1843: ** ^If SQLite is compiled with
1844: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1845: ** it is not possible to set the Serialized [threading mode] and
1846: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1847: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1848: **
1849: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1850: ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1851: ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1852: ** The argument specifies
1853: ** alternative low-level memory allocation routines to be used in place of
1854: ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1855: ** its own private copy of the content of the [sqlite3_mem_methods] structure
1856: ** before the [sqlite3_config()] call returns.</dd>
1857: **
1858: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1859: ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1860: ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1861: ** The [sqlite3_mem_methods]
1862: ** structure is filled with the currently defined memory allocation routines.)^
1863: ** This option can be used to overload the default memory allocation
1864: ** routines with a wrapper that simulations memory allocation failure or
1865: ** tracks memory usage, for example. </dd>
1866: **
1867: ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1868: ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1869: ** type int, interpreted as a boolean, which if true provides a hint to
1870: ** SQLite that it should avoid large memory allocations if possible.
1871: ** SQLite will run faster if it is free to make large memory allocations,
1872: ** but some application might prefer to run slower in exchange for
1873: ** guarantees about memory fragmentation that are possible if large
1874: ** allocations are avoided. This hint is normally off.
1875: ** </dd>
1876: **
1877: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1878: ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1879: ** interpreted as a boolean, which enables or disables the collection of
1880: ** memory allocation statistics. ^(When memory allocation statistics are
1881: ** disabled, the following SQLite interfaces become non-operational:
1882: ** <ul>
1883: ** <li> [sqlite3_hard_heap_limit64()]
1884: ** <li> [sqlite3_memory_used()]
1885: ** <li> [sqlite3_memory_highwater()]
1886: ** <li> [sqlite3_soft_heap_limit64()]
1887: ** <li> [sqlite3_status64()]
1888: ** </ul>)^
1889: ** ^Memory allocation statistics are enabled by default unless SQLite is
1890: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1891: ** allocation statistics are disabled by default.
1892: ** </dd>
1893: **
1894: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1895: ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1896: ** </dd>
1897: **
1898: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1899: ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1900: ** that SQLite can use for the database page cache with the default page
1901: ** cache implementation.
1902: ** This configuration option is a no-op if an application-defined page
1903: ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1904: ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1905: ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1906: ** and the number of cache lines (N).
1907: ** The sz argument should be the size of the largest database page
1908: ** (a power of two between 512 and 65536) plus some extra bytes for each
1909: ** page header. ^The number of extra bytes needed by the page header
1910: ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1911: ** ^It is harmless, apart from the wasted memory,
1912: ** for the sz parameter to be larger than necessary. The pMem
1913: ** argument must be either a NULL pointer or a pointer to an 8-byte
1914: ** aligned block of memory of at least sz*N bytes, otherwise
1915: ** subsequent behavior is undefined.
1916: ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1917: ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1918: ** a page cache line is larger than sz bytes or if all of the pMem buffer
1919: ** is exhausted.
1920: ** ^If pMem is NULL and N is non-zero, then each database connection
1921: ** does an initial bulk allocation for page cache memory
1922: ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1923: ** of -1024*N bytes if N is negative, . ^If additional
1924: ** page cache memory is needed beyond what is provided by the initial
1925: ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1926: ** additional cache line. </dd>
1927: **
1928: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1929: ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1930: ** that SQLite will use for all of its dynamic memory allocation needs
1931: ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1932: ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1933: ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1934: ** [SQLITE_ERROR] if invoked otherwise.
1935: ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1936: ** An 8-byte aligned pointer to the memory,
1937: ** the number of bytes in the memory buffer, and the minimum allocation size.
1938: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1939: ** to using its default memory allocator (the system malloc() implementation),
1940: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1941: ** memory pointer is not NULL then the alternative memory
1942: ** allocator is engaged to handle all of SQLites memory allocation needs.
1943: ** The first pointer (the memory pointer) must be aligned to an 8-byte
1944: ** boundary or subsequent behavior of SQLite will be undefined.
1945: ** The minimum allocation size is capped at 2**12. Reasonable values
1946: ** for the minimum allocation size are 2**5 through 2**8.</dd>
1947: **
1948: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1949: ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1950: ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1951: ** The argument specifies alternative low-level mutex routines to be used
1952: ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1953: ** the content of the [sqlite3_mutex_methods] structure before the call to
1954: ** [sqlite3_config()] returns. ^If SQLite is compiled with
1955: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1956: ** the entire mutexing subsystem is omitted from the build and hence calls to
1957: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1958: ** return [SQLITE_ERROR].</dd>
1959: **
1960: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1961: ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1962: ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1963: ** [sqlite3_mutex_methods]
1964: ** structure is filled with the currently defined mutex routines.)^
1965: ** This option can be used to overload the default mutex allocation
1966: ** routines with a wrapper used to track mutex usage for performance
1967: ** profiling or testing, for example. ^If SQLite is compiled with
1968: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1969: ** the entire mutexing subsystem is omitted from the build and hence calls to
1970: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1971: ** return [SQLITE_ERROR].</dd>
1972: **
1973: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1974: ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1975: ** the default size of lookaside memory on each [database connection].
1976: ** The first argument is the
1977: ** size of each lookaside buffer slot and the second is the number of
1978: ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1979: ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1980: ** option to [sqlite3_db_config()] can be used to change the lookaside
1981: ** configuration on individual connections.)^ </dd>
1982: **
1983: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1984: ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1985: ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1986: ** the interface to a custom page cache implementation.)^
1987: ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1988: **
1989: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1990: ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1991: ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1992: ** the current page cache implementation into that object.)^ </dd>
1993: **
1994: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1995: ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1996: ** global [error log].
1997: ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1998: ** function with a call signature of void(*)(void*,int,const char*),
1999: ** and a pointer to void. ^If the function pointer is not NULL, it is
2000: ** invoked by [sqlite3_log()] to process each logging event. ^If the
2001: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2002: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2003: ** passed through as the first parameter to the application-defined logger
2004: ** function whenever that function is invoked. ^The second parameter to
2005: ** the logger function is a copy of the first parameter to the corresponding
2006: ** [sqlite3_log()] call and is intended to be a [result code] or an
2007: ** [extended result code]. ^The third parameter passed to the logger is
2008: ** log message after formatting via [sqlite3_snprintf()].
2009: ** The SQLite logging interface is not reentrant; the logger function
2010: ** supplied by the application must not invoke any SQLite interface.
2011: ** In a multi-threaded application, the application-defined logger
2012: ** function must be threadsafe. </dd>
2013: **
2014: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2015: ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2016: ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2017: ** then URI handling is globally disabled.)^ ^If URI handling is globally
2018: ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2019: ** [sqlite3_open16()] or
2020: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2021: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2022: ** connection is opened. ^If it is globally disabled, filenames are
2023: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2024: ** database connection is opened. ^(By default, URI handling is globally
2025: ** disabled. The default value may be changed by compiling with the
2026: ** [SQLITE_USE_URI] symbol defined.)^
2027: **
2028: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2029: ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2030: ** argument which is interpreted as a boolean in order to enable or disable
2031: ** the use of covering indices for full table scans in the query optimizer.
2032: ** ^The default setting is determined
2033: ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2034: ** if that compile-time option is omitted.
2035: ** The ability to disable the use of covering indices for full table scans
2036: ** is because some incorrectly coded legacy applications might malfunction
2037: ** when the optimization is enabled. Providing the ability to
2038: ** disable the optimization allows the older, buggy application code to work
2039: ** without change even with newer versions of SQLite.
2040: **
2041: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2042: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2043: ** <dd> These options are obsolete and should not be used by new code.
2044: ** They are retained for backwards compatibility but are now no-ops.
2045: ** </dd>
2046: **
2047: ** [[SQLITE_CONFIG_SQLLOG]]
2048: ** <dt>SQLITE_CONFIG_SQLLOG
2049: ** <dd>This option is only available if sqlite is compiled with the
2050: ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2051: ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2052: ** The second should be of type (void*). The callback is invoked by the library
2053: ** in three separate circumstances, identified by the value passed as the
2054: ** fourth parameter. If the fourth parameter is 0, then the database connection
2055: ** passed as the second argument has just been opened. The third argument
2056: ** points to a buffer containing the name of the main database file. If the
2057: ** fourth parameter is 1, then the SQL statement that the third parameter
2058: ** points to has just been executed. Or, if the fourth parameter is 2, then
2059: ** the connection being passed as the second parameter is being closed. The
2060: ** third parameter is passed NULL In this case. An example of using this
2061: ** configuration option can be seen in the "test_sqllog.c" source file in
2062: ** the canonical SQLite source tree.</dd>
2063: **
2064: ** [[SQLITE_CONFIG_MMAP_SIZE]]
2065: ** <dt>SQLITE_CONFIG_MMAP_SIZE
2066: ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2067: ** that are the default mmap size limit (the default setting for
2068: ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2069: ** ^The default setting can be overridden by each database connection using
2070: ** either the [PRAGMA mmap_size] command, or by using the
2071: ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2072: ** will be silently truncated if necessary so that it does not exceed the
2073: ** compile-time maximum mmap size set by the
2074: ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2075: ** ^If either argument to this option is negative, then that argument is
2076: ** changed to its compile-time default.
2077: **
2078: ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2079: ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2080: ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2081: ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2082: ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2083: ** that specifies the maximum size of the created heap.
2084: **
2085: ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2086: ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2087: ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2088: ** is a pointer to an integer and writes into that integer the number of extra
2089: ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2090: ** The amount of extra space required can change depending on the compiler,
2091: ** target platform, and SQLite version.
2092: **
2093: ** [[SQLITE_CONFIG_PMASZ]]
2094: ** <dt>SQLITE_CONFIG_PMASZ
2095: ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2096: ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2097: ** sorter to that integer. The default minimum PMA Size is set by the
2098: ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2099: ** to help with sort operations when multithreaded sorting
2100: ** is enabled (using the [PRAGMA threads] command) and the amount of content
2101: ** to be sorted exceeds the page size times the minimum of the
2102: ** [PRAGMA cache_size] setting and this value.
2103: **
2104: ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2105: ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2106: ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2107: ** becomes the [statement journal] spill-to-disk threshold.
2108: ** [Statement journals] are held in memory until their size (in bytes)
2109: ** exceeds this threshold, at which point they are written to disk.
2110: ** Or if the threshold is -1, statement journals are always held
2111: ** exclusively in memory.
2112: ** Since many statement journals never become large, setting the spill
2113: ** threshold to a value such as 64KiB can greatly reduce the amount of
2114: ** I/O required to support statement rollback.
2115: ** The default value for this setting is controlled by the
2116: ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2117: **
2118: ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2119: ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2120: ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2121: ** of type (int) - the new value of the sorter-reference size threshold.
2122: ** Usually, when SQLite uses an external sort to order records according
2123: ** to an ORDER BY clause, all fields required by the caller are present in the
2124: ** sorted records. However, if SQLite determines based on the declared type
2125: ** of a table column that its values are likely to be very large - larger
2126: ** than the configured sorter-reference size threshold - then a reference
2127: ** is stored in each sorted record and the required column values loaded
2128: ** from the database as records are returned in sorted order. The default
2129: ** value for this option is to never use this optimization. Specifying a
2130: ** negative value for this option restores the default behaviour.
2131: ** This option is only available if SQLite is compiled with the
2132: ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2133: **
2134: ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2135: ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2136: ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2137: ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2138: ** database created using [sqlite3_deserialize()]. This default maximum
2139: ** size can be adjusted up or down for individual databases using the
2140: ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2141: ** configuration setting is never used, then the default maximum is determined
2142: ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2143: ** compile-time option is not set, then the default maximum is 1073741824.
2144: ** </dl>
2145: */
2146: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2147: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2148: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2149: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2150: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2151: #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2152: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2153: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2154: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2155: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2156: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2157: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2158: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2159: #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2160: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2161: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2162: #define SQLITE_CONFIG_URI 17 /* int */
2163: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2164: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2165: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2166: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2167: #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2168: #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2169: #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2170: #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2171: #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2172: #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2173: #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2174: #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2175:
2176: /*
2177: ** CAPI3REF: Database Connection Configuration Options
2178: **
2179: ** These constants are the available integer configuration options that
2180: ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2181: **
2182: ** New configuration options may be added in future releases of SQLite.
2183: ** Existing configuration options might be discontinued. Applications
2184: ** should check the return code from [sqlite3_db_config()] to make sure that
2185: ** the call worked. ^The [sqlite3_db_config()] interface will return a
2186: ** non-zero [error code] if a discontinued or unsupported configuration option
2187: ** is invoked.
2188: **
2189: ** <dl>
2190: ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2191: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2192: ** <dd> ^This option takes three additional arguments that determine the
2193: ** [lookaside memory allocator] configuration for the [database connection].
2194: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2195: ** pointer to a memory buffer to use for lookaside memory.
2196: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2197: ** may be NULL in which case SQLite will allocate the
2198: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2199: ** size of each lookaside buffer slot. ^The third argument is the number of
2200: ** slots. The size of the buffer in the first argument must be greater than
2201: ** or equal to the product of the second and third arguments. The buffer
2202: ** must be aligned to an 8-byte boundary. ^If the second argument to
2203: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2204: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2205: ** configuration for a database connection can only be changed when that
2206: ** connection is not currently using lookaside memory, or in other words
2207: ** when the "current value" returned by
2208: ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero.
2209: ** Any attempt to change the lookaside memory configuration when lookaside
2210: ** memory is in use leaves the configuration unchanged and returns
2211: ** [SQLITE_BUSY].)^</dd>
2212: **
2213: ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2214: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2215: ** <dd> ^This option is used to enable or disable the enforcement of
2216: ** [foreign key constraints]. There should be two additional arguments.
2217: ** The first argument is an integer which is 0 to disable FK enforcement,
2218: ** positive to enable FK enforcement or negative to leave FK enforcement
2219: ** unchanged. The second parameter is a pointer to an integer into which
2220: ** is written 0 or 1 to indicate whether FK enforcement is off or on
2221: ** following this call. The second parameter may be a NULL pointer, in
2222: ** which case the FK enforcement setting is not reported back. </dd>
2223: **
2224: ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2225: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2226: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2227: ** There should be two additional arguments.
2228: ** The first argument is an integer which is 0 to disable triggers,
2229: ** positive to enable triggers or negative to leave the setting unchanged.
2230: ** The second parameter is a pointer to an integer into which
2231: ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2232: ** following this call. The second parameter may be a NULL pointer, in
2233: ** which case the trigger setting is not reported back.
2234: **
2235: ** <p>Originally this option disabled all triggers. ^(However, since
2236: ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2237: ** this option is off. So, in other words, this option now only disables
2238: ** triggers in the main database schema or in the schemas of ATTACH-ed
2239: ** databases.)^ </dd>
2240: **
2241: ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2242: ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2243: ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2244: ** There should be two additional arguments.
2245: ** The first argument is an integer which is 0 to disable views,
2246: ** positive to enable views or negative to leave the setting unchanged.
2247: ** The second parameter is a pointer to an integer into which
2248: ** is written 0 or 1 to indicate whether views are disabled or enabled
2249: ** following this call. The second parameter may be a NULL pointer, in
2250: ** which case the view setting is not reported back.
2251: **
2252: ** <p>Originally this option disabled all views. ^(However, since
2253: ** SQLite version 3.35.0, TEMP views are still allowed even if
2254: ** this option is off. So, in other words, this option now only disables
2255: ** views in the main database schema or in the schemas of ATTACH-ed
2256: ** databases.)^ </dd>
2257: **
2258: ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2259: ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2260: ** <dd> ^This option is used to enable or disable the
2261: ** [fts3_tokenizer()] function which is part of the
2262: ** [FTS3] full-text search engine extension.
2263: ** There should be two additional arguments.
2264: ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2265: ** positive to enable fts3_tokenizer() or negative to leave the setting
2266: ** unchanged.
2267: ** The second parameter is a pointer to an integer into which
2268: ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2269: ** following this call. The second parameter may be a NULL pointer, in
2270: ** which case the new setting is not reported back. </dd>
2271: **
2272: ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2273: ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2274: ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2275: ** interface independently of the [load_extension()] SQL function.
2276: ** The [sqlite3_enable_load_extension()] API enables or disables both the
2277: ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2278: ** There should be two additional arguments.
2279: ** When the first argument to this interface is 1, then only the C-API is
2280: ** enabled and the SQL function remains disabled. If the first argument to
2281: ** this interface is 0, then both the C-API and the SQL function are disabled.
2282: ** If the first argument is -1, then no changes are made to state of either the
2283: ** C-API or the SQL function.
2284: ** The second parameter is a pointer to an integer into which
2285: ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2286: ** is disabled or enabled following this call. The second parameter may
2287: ** be a NULL pointer, in which case the new setting is not reported back.
2288: ** </dd>
2289: **
2290: ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2291: ** <dd> ^This option is used to change the name of the "main" database
2292: ** schema. ^The sole argument is a pointer to a constant UTF8 string
2293: ** which will become the new schema name in place of "main". ^SQLite
2294: ** does not make a copy of the new main schema name string, so the application
2295: ** must ensure that the argument passed into this DBCONFIG option is unchanged
2296: ** until after the database connection closes.
2297: ** </dd>
2298: **
2299: ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2300: ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2301: ** <dd> Usually, when a database in wal mode is closed or detached from a
2302: ** database handle, SQLite checks if this will mean that there are now no
2303: ** connections at all to the database. If so, it performs a checkpoint
2304: ** operation before closing the connection. This option may be used to
2305: ** override this behaviour. The first parameter passed to this operation
2306: ** is an integer - positive to disable checkpoints-on-close, or zero (the
2307: ** default) to enable them, and negative to leave the setting unchanged.
2308: ** The second parameter is a pointer to an integer
2309: ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2310: ** have been disabled - 0 if they are not disabled, 1 if they are.
2311: ** </dd>
2312: **
2313: ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2314: ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2315: ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2316: ** a single SQL query statement will always use the same algorithm regardless
2317: ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2318: ** that look at the values of bound parameters, which can make some queries
2319: ** slower. But the QPSG has the advantage of more predictable behavior. With
2320: ** the QPSG active, SQLite will always use the same query plan in the field as
2321: ** was used during testing in the lab.
2322: ** The first argument to this setting is an integer which is 0 to disable
2323: ** the QPSG, positive to enable QPSG, or negative to leave the setting
2324: ** unchanged. The second parameter is a pointer to an integer into which
2325: ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2326: ** following this call.
2327: ** </dd>
2328: **
2329: ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2330: ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2331: ** include output for any operations performed by trigger programs. This
2332: ** option is used to set or clear (the default) a flag that governs this
2333: ** behavior. The first parameter passed to this operation is an integer -
2334: ** positive to enable output for trigger programs, or zero to disable it,
2335: ** or negative to leave the setting unchanged.
2336: ** The second parameter is a pointer to an integer into which is written
2337: ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2338: ** it is not disabled, 1 if it is.
2339: ** </dd>
2340: **
2341: ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2342: ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2343: ** [VACUUM] in order to reset a database back to an empty database
2344: ** with no schema and no content. The following process works even for
2345: ** a badly corrupted database file:
2346: ** <ol>
2347: ** <li> If the database connection is newly opened, make sure it has read the
2348: ** database schema by preparing then discarding some query against the
2349: ** database, or calling sqlite3_table_column_metadata(), ignoring any
2350: ** errors. This step is only necessary if the application desires to keep
2351: ** the database in WAL mode after the reset if it was in WAL mode before
2352: ** the reset.
2353: ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2354: ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2355: ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2356: ** </ol>
2357: ** Because resetting a database is destructive and irreversible, the
2358: ** process requires the use of this obscure API and multiple steps to
2359: ** help ensure that it does not happen by accident. Because this
2360: ** feature must be capable of resetting corrupt databases, and
2361: ** shutting down virtual tables may require access to that corrupt
2362: ** storage, the library must abandon any installed virtual tables
2363: ** without calling their xDestroy() methods.
2364: **
2365: ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2366: ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2367: ** "defensive" flag for a database connection. When the defensive
2368: ** flag is enabled, language features that allow ordinary SQL to
2369: ** deliberately corrupt the database file are disabled. The disabled
2370: ** features include but are not limited to the following:
2371: ** <ul>
2372: ** <li> The [PRAGMA writable_schema=ON] statement.
2373: ** <li> The [PRAGMA journal_mode=OFF] statement.
2374: ** <li> The [PRAGMA schema_version=N] statement.
2375: ** <li> Writes to the [sqlite_dbpage] virtual table.
2376: ** <li> Direct writes to [shadow tables].
2377: ** </ul>
2378: ** </dd>
2379: **
2380: ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2381: ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2382: ** "writable_schema" flag. This has the same effect and is logically equivalent
2383: ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2384: ** The first argument to this setting is an integer which is 0 to disable
2385: ** the writable_schema, positive to enable writable_schema, or negative to
2386: ** leave the setting unchanged. The second parameter is a pointer to an
2387: ** integer into which is written 0 or 1 to indicate whether the writable_schema
2388: ** is enabled or disabled following this call.
2389: ** </dd>
2390: **
2391: ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2392: ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2393: ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2394: ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2395: ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2396: ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2397: ** additional information. This feature can also be turned on and off
2398: ** using the [PRAGMA legacy_alter_table] statement.
2399: ** </dd>
2400: **
2401: ** [[SQLITE_DBCONFIG_DQS_DML]]
2402: ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2403: ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2404: ** the legacy [double-quoted string literal] misfeature for DML statements
2405: ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2406: ** default value of this setting is determined by the [-DSQLITE_DQS]
2407: ** compile-time option.
2408: ** </dd>
2409: **
2410: ** [[SQLITE_DBCONFIG_DQS_DDL]]
2411: ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2412: ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2413: ** the legacy [double-quoted string literal] misfeature for DDL statements,
2414: ** such as CREATE TABLE and CREATE INDEX. The
2415: ** default value of this setting is determined by the [-DSQLITE_DQS]
2416: ** compile-time option.
2417: ** </dd>
2418: **
2419: ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2420: ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2421: ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2422: ** assume that database schemas are untainted by malicious content.
2423: ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2424: ** takes additional defensive steps to protect the application from harm
2425: ** including:
2426: ** <ul>
2427: ** <li> Prohibit the use of SQL functions inside triggers, views,
2428: ** CHECK constraints, DEFAULT clauses, expression indexes,
2429: ** partial indexes, or generated columns
2430: ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2431: ** <li> Prohibit the use of virtual tables inside of triggers or views
2432: ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2433: ** </ul>
2434: ** This setting defaults to "on" for legacy compatibility, however
2435: ** all applications are advised to turn it off if possible. This setting
2436: ** can also be controlled using the [PRAGMA trusted_schema] statement.
2437: ** </dd>
2438: **
2439: ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2440: ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2441: ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2442: ** the legacy file format flag. When activated, this flag causes all newly
2443: ** created database file to have a schema format version number (the 4-byte
2444: ** integer found at offset 44 into the database header) of 1. This in turn
2445: ** means that the resulting database file will be readable and writable by
2446: ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2447: ** newly created databases are generally not understandable by SQLite versions
2448: ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2449: ** is now scarcely any need to generate database files that are compatible
2450: ** all the way back to version 3.0.0, and so this setting is of little
2451: ** practical use, but is provided so that SQLite can continue to claim the
2452: ** ability to generate new database files that are compatible with version
2453: ** 3.0.0.
2454: ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2455: ** the [VACUUM] command will fail with an obscure error when attempting to
2456: ** process a table with generated columns and a descending index. This is
2457: ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2458: ** either generated columns or descending indexes.
2459: ** </dd>
2460: **
2461: ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2462: ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2463: ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2464: ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2465: ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2466: ** statistics. For statistics to be collected, the flag must be set on
2467: ** the database handle both when the SQL statement is prepared and when it
2468: ** is stepped. The flag is set (collection of statistics is enabled)
2469: ** by default. This option takes two arguments: an integer and a pointer to
2470: ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2471: ** leave unchanged the statement scanstatus option. If the second argument
2472: ** is not NULL, then the value of the statement scanstatus setting after
2473: ** processing the first argument is written into the integer that the second
2474: ** argument points to.
2475: ** </dd>
2476: **
2477: ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2478: ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2479: ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2480: ** in which tables and indexes are scanned so that the scans start at the end
2481: ** and work toward the beginning rather than starting at the beginning and
2482: ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2483: ** same as setting [PRAGMA reverse_unordered_selects]. This option takes
2484: ** two arguments which are an integer and a pointer to an integer. The first
2485: ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2486: ** reverse scan order flag, respectively. If the second argument is not NULL,
2487: ** then 0 or 1 is written into the integer that the second argument points to
2488: ** depending on if the reverse scan order flag is set after processing the
2489: ** first argument.
2490: ** </dd>
2491: **
2492: ** </dl>
2493: */
2494: #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2495: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2496: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2497: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2498: #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2499: #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2500: #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2501: #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2502: #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2503: #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2504: #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2505: #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2506: #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2507: #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2508: #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2509: #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2510: #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2511: #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2512: #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2513: #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2514: #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */
2515:
2516: /*
2517: ** CAPI3REF: Enable Or Disable Extended Result Codes
2518: ** METHOD: sqlite3
2519: **
2520: ** ^The sqlite3_extended_result_codes() routine enables or disables the
2521: ** [extended result codes] feature of SQLite. ^The extended result
2522: ** codes are disabled by default for historical compatibility.
2523: */
2524: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2525:
2526: /*
2527: ** CAPI3REF: Last Insert Rowid
2528: ** METHOD: sqlite3
2529: **
2530: ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2531: ** has a unique 64-bit signed
2532: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2533: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2534: ** names are not also used by explicitly declared columns. ^If
2535: ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2536: ** is another alias for the rowid.
2537: **
2538: ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2539: ** the most recent successful [INSERT] into a rowid table or [virtual table]
2540: ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2541: ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2542: ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2543: ** zero.
2544: **
2545: ** As well as being set automatically as rows are inserted into database
2546: ** tables, the value returned by this function may be set explicitly by
2547: ** [sqlite3_set_last_insert_rowid()]
2548: **
2549: ** Some virtual table implementations may INSERT rows into rowid tables as
2550: ** part of committing a transaction (e.g. to flush data accumulated in memory
2551: ** to disk). In this case subsequent calls to this function return the rowid
2552: ** associated with these internal INSERT operations, which leads to
2553: ** unintuitive results. Virtual table implementations that do write to rowid
2554: ** tables in this way can avoid this problem by restoring the original
2555: ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2556: ** control to the user.
2557: **
2558: ** ^(If an [INSERT] occurs within a trigger then this routine will
2559: ** return the [rowid] of the inserted row as long as the trigger is
2560: ** running. Once the trigger program ends, the value returned
2561: ** by this routine reverts to what it was before the trigger was fired.)^
2562: **
2563: ** ^An [INSERT] that fails due to a constraint violation is not a
2564: ** successful [INSERT] and does not change the value returned by this
2565: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2566: ** and INSERT OR ABORT make no changes to the return value of this
2567: ** routine when their insertion fails. ^(When INSERT OR REPLACE
2568: ** encounters a constraint violation, it does not fail. The
2569: ** INSERT continues to completion after deleting rows that caused
2570: ** the constraint problem so INSERT OR REPLACE will always change
2571: ** the return value of this interface.)^
2572: **
2573: ** ^For the purposes of this routine, an [INSERT] is considered to
2574: ** be successful even if it is subsequently rolled back.
2575: **
2576: ** This function is accessible to SQL statements via the
2577: ** [last_insert_rowid() SQL function].
2578: **
2579: ** If a separate thread performs a new [INSERT] on the same
2580: ** database connection while the [sqlite3_last_insert_rowid()]
2581: ** function is running and thus changes the last insert [rowid],
2582: ** then the value returned by [sqlite3_last_insert_rowid()] is
2583: ** unpredictable and might not equal either the old or the new
2584: ** last insert [rowid].
2585: */
2586: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2587:
2588: /*
2589: ** CAPI3REF: Set the Last Insert Rowid value.
2590: ** METHOD: sqlite3
2591: **
2592: ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2593: ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2594: ** without inserting a row into the database.
2595: */
2596: SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2597:
2598: /*
2599: ** CAPI3REF: Count The Number Of Rows Modified
2600: ** METHOD: sqlite3
2601: **
2602: ** ^These functions return the number of rows modified, inserted or
2603: ** deleted by the most recently completed INSERT, UPDATE or DELETE
2604: ** statement on the database connection specified by the only parameter.
2605: ** The two functions are identical except for the type of the return value
2606: ** and that if the number of rows modified by the most recent INSERT, UPDATE
2607: ** or DELETE is greater than the maximum value supported by type "int", then
2608: ** the return value of sqlite3_changes() is undefined. ^Executing any other
2609: ** type of SQL statement does not modify the value returned by these functions.
2610: **
2611: ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2612: ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2613: ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2614: **
2615: ** Changes to a view that are intercepted by
2616: ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2617: ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2618: ** DELETE statement run on a view is always zero. Only changes made to real
2619: ** tables are counted.
2620: **
2621: ** Things are more complicated if the sqlite3_changes() function is
2622: ** executed while a trigger program is running. This may happen if the
2623: ** program uses the [changes() SQL function], or if some other callback
2624: ** function invokes sqlite3_changes() directly. Essentially:
2625: **
2626: ** <ul>
2627: ** <li> ^(Before entering a trigger program the value returned by
2628: ** sqlite3_changes() function is saved. After the trigger program
2629: ** has finished, the original value is restored.)^
2630: **
2631: ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2632: ** statement sets the value returned by sqlite3_changes()
2633: ** upon completion as normal. Of course, this value will not include
2634: ** any changes performed by sub-triggers, as the sqlite3_changes()
2635: ** value will be saved and restored after each sub-trigger has run.)^
2636: ** </ul>
2637: **
2638: ** ^This means that if the changes() SQL function (or similar) is used
2639: ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2640: ** returns the value as set when the calling statement began executing.
2641: ** ^If it is used by the second or subsequent such statement within a trigger
2642: ** program, the value returned reflects the number of rows modified by the
2643: ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2644: **
2645: ** If a separate thread makes changes on the same database connection
2646: ** while [sqlite3_changes()] is running then the value returned
2647: ** is unpredictable and not meaningful.
2648: **
2649: ** See also:
2650: ** <ul>
2651: ** <li> the [sqlite3_total_changes()] interface
2652: ** <li> the [count_changes pragma]
2653: ** <li> the [changes() SQL function]
2654: ** <li> the [data_version pragma]
2655: ** </ul>
2656: */
2657: SQLITE_API int sqlite3_changes(sqlite3*);
2658: SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2659:
2660: /*
2661: ** CAPI3REF: Total Number Of Rows Modified
2662: ** METHOD: sqlite3
2663: **
2664: ** ^These functions return the total number of rows inserted, modified or
2665: ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2666: ** since the database connection was opened, including those executed as
2667: ** part of trigger programs. The two functions are identical except for the
2668: ** type of the return value and that if the number of rows modified by the
2669: ** connection exceeds the maximum value supported by type "int", then
2670: ** the return value of sqlite3_total_changes() is undefined. ^Executing
2671: ** any other type of SQL statement does not affect the value returned by
2672: ** sqlite3_total_changes().
2673: **
2674: ** ^Changes made as part of [foreign key actions] are included in the
2675: ** count, but those made as part of REPLACE constraint resolution are
2676: ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2677: ** are not counted.
2678: **
2679: ** The [sqlite3_total_changes(D)] interface only reports the number
2680: ** of rows that changed due to SQL statement run against database
2681: ** connection D. Any changes by other database connections are ignored.
2682: ** To detect changes against a database file from other database
2683: ** connections use the [PRAGMA data_version] command or the
2684: ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2685: **
2686: ** If a separate thread makes changes on the same database connection
2687: ** while [sqlite3_total_changes()] is running then the value
2688: ** returned is unpredictable and not meaningful.
2689: **
2690: ** See also:
2691: ** <ul>
2692: ** <li> the [sqlite3_changes()] interface
2693: ** <li> the [count_changes pragma]
2694: ** <li> the [changes() SQL function]
2695: ** <li> the [data_version pragma]
2696: ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2697: ** </ul>
2698: */
2699: SQLITE_API int sqlite3_total_changes(sqlite3*);
2700: SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2701:
2702: /*
2703: ** CAPI3REF: Interrupt A Long-Running Query
2704: ** METHOD: sqlite3
2705: **
2706: ** ^This function causes any pending database operation to abort and
2707: ** return at its earliest opportunity. This routine is typically
2708: ** called in response to a user action such as pressing "Cancel"
2709: ** or Ctrl-C where the user wants a long query operation to halt
2710: ** immediately.
2711: **
2712: ** ^It is safe to call this routine from a thread different from the
2713: ** thread that is currently running the database operation. But it
2714: ** is not safe to call this routine with a [database connection] that
2715: ** is closed or might close before sqlite3_interrupt() returns.
2716: **
2717: ** ^If an SQL operation is very nearly finished at the time when
2718: ** sqlite3_interrupt() is called, then it might not have an opportunity
2719: ** to be interrupted and might continue to completion.
2720: **
2721: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2722: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2723: ** that is inside an explicit transaction, then the entire transaction
2724: ** will be rolled back automatically.
2725: **
2726: ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2727: ** SQL statements on [database connection] D complete. ^Any new SQL statements
2728: ** that are started after the sqlite3_interrupt() call and before the
2729: ** running statement count reaches zero are interrupted as if they had been
2730: ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2731: ** that are started after the running statement count reaches zero are
2732: ** not effected by the sqlite3_interrupt().
2733: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2734: ** SQL statements is a no-op and has no effect on SQL statements
2735: ** that are started after the sqlite3_interrupt() call returns.
2736: **
2737: ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2738: ** or not an interrupt is currently in effect for [database connection] D.
2739: ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2740: */
2741: SQLITE_API void sqlite3_interrupt(sqlite3*);
2742: SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2743:
2744: /*
2745: ** CAPI3REF: Determine If An SQL Statement Is Complete
2746: **
2747: ** These routines are useful during command-line input to determine if the
2748: ** currently entered text seems to form a complete SQL statement or
2749: ** if additional input is needed before sending the text into
2750: ** SQLite for parsing. ^These routines return 1 if the input string
2751: ** appears to be a complete SQL statement. ^A statement is judged to be
2752: ** complete if it ends with a semicolon token and is not a prefix of a
2753: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2754: ** string literals or quoted identifier names or comments are not
2755: ** independent tokens (they are part of the token in which they are
2756: ** embedded) and thus do not count as a statement terminator. ^Whitespace
2757: ** and comments that follow the final semicolon are ignored.
2758: **
2759: ** ^These routines return 0 if the statement is incomplete. ^If a
2760: ** memory allocation fails, then SQLITE_NOMEM is returned.
2761: **
2762: ** ^These routines do not parse the SQL statements thus
2763: ** will not detect syntactically incorrect SQL.
2764: **
2765: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2766: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2767: ** automatically by sqlite3_complete16(). If that initialization fails,
2768: ** then the return value from sqlite3_complete16() will be non-zero
2769: ** regardless of whether or not the input SQL is complete.)^
2770: **
2771: ** The input to [sqlite3_complete()] must be a zero-terminated
2772: ** UTF-8 string.
2773: **
2774: ** The input to [sqlite3_complete16()] must be a zero-terminated
2775: ** UTF-16 string in native byte order.
2776: */
2777: SQLITE_API int sqlite3_complete(const char *sql);
2778: SQLITE_API int sqlite3_complete16(const void *sql);
2779:
2780: /*
2781: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2782: ** KEYWORDS: {busy-handler callback} {busy handler}
2783: ** METHOD: sqlite3
2784: **
2785: ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2786: ** that might be invoked with argument P whenever
2787: ** an attempt is made to access a database table associated with
2788: ** [database connection] D when another thread
2789: ** or process has the table locked.
2790: ** The sqlite3_busy_handler() interface is used to implement
2791: ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2792: **
2793: ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2794: ** is returned immediately upon encountering the lock. ^If the busy callback
2795: ** is not NULL, then the callback might be invoked with two arguments.
2796: **
2797: ** ^The first argument to the busy handler is a copy of the void* pointer which
2798: ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2799: ** the busy handler callback is the number of times that the busy handler has
2800: ** been invoked previously for the same locking event. ^If the
2801: ** busy callback returns 0, then no additional attempts are made to
2802: ** access the database and [SQLITE_BUSY] is returned
2803: ** to the application.
2804: ** ^If the callback returns non-zero, then another attempt
2805: ** is made to access the database and the cycle repeats.
2806: **
2807: ** The presence of a busy handler does not guarantee that it will be invoked
2808: ** when there is lock contention. ^If SQLite determines that invoking the busy
2809: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2810: ** to the application instead of invoking the
2811: ** busy handler.
2812: ** Consider a scenario where one process is holding a read lock that
2813: ** it is trying to promote to a reserved lock and
2814: ** a second process is holding a reserved lock that it is trying
2815: ** to promote to an exclusive lock. The first process cannot proceed
2816: ** because it is blocked by the second and the second process cannot
2817: ** proceed because it is blocked by the first. If both processes
2818: ** invoke the busy handlers, neither will make any progress. Therefore,
2819: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2820: ** will induce the first process to release its read lock and allow
2821: ** the second process to proceed.
2822: **
2823: ** ^The default busy callback is NULL.
2824: **
2825: ** ^(There can only be a single busy handler defined for each
2826: ** [database connection]. Setting a new busy handler clears any
2827: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2828: ** or evaluating [PRAGMA busy_timeout=N] will change the
2829: ** busy handler and thus clear any previously set busy handler.
2830: **
2831: ** The busy callback should not take any actions which modify the
2832: ** database connection that invoked the busy handler. In other words,
2833: ** the busy handler is not reentrant. Any such actions
2834: ** result in undefined behavior.
2835: **
2836: ** A busy handler must not close the database connection
2837: ** or [prepared statement] that invoked the busy handler.
2838: */
2839: SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2840:
2841: /*
2842: ** CAPI3REF: Set A Busy Timeout
2843: ** METHOD: sqlite3
2844: **
2845: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2846: ** for a specified amount of time when a table is locked. ^The handler
2847: ** will sleep multiple times until at least "ms" milliseconds of sleeping
2848: ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2849: ** the handler returns 0 which causes [sqlite3_step()] to return
2850: ** [SQLITE_BUSY].
2851: **
2852: ** ^Calling this routine with an argument less than or equal to zero
2853: ** turns off all busy handlers.
2854: **
2855: ** ^(There can only be a single busy handler for a particular
2856: ** [database connection] at any given moment. If another busy handler
2857: ** was defined (using [sqlite3_busy_handler()]) prior to calling
2858: ** this routine, that other busy handler is cleared.)^
2859: **
2860: ** See also: [PRAGMA busy_timeout]
2861: */
2862: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2863:
2864: /*
2865: ** CAPI3REF: Convenience Routines For Running Queries
2866: ** METHOD: sqlite3
2867: **
2868: ** This is a legacy interface that is preserved for backwards compatibility.
2869: ** Use of this interface is not recommended.
2870: **
2871: ** Definition: A <b>result table</b> is memory data structure created by the
2872: ** [sqlite3_get_table()] interface. A result table records the
2873: ** complete query results from one or more queries.
2874: **
2875: ** The table conceptually has a number of rows and columns. But
2876: ** these numbers are not part of the result table itself. These
2877: ** numbers are obtained separately. Let N be the number of rows
2878: ** and M be the number of columns.
2879: **
2880: ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2881: ** There are (N+1)*M elements in the array. The first M pointers point
2882: ** to zero-terminated strings that contain the names of the columns.
2883: ** The remaining entries all point to query results. NULL values result
2884: ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2885: ** string representation as returned by [sqlite3_column_text()].
2886: **
2887: ** A result table might consist of one or more memory allocations.
2888: ** It is not safe to pass a result table directly to [sqlite3_free()].
2889: ** A result table should be deallocated using [sqlite3_free_table()].
2890: **
2891: ** ^(As an example of the result table format, suppose a query result
2892: ** is as follows:
2893: **
2894: ** <blockquote><pre>
2895: ** Name | Age
2896: ** -----------------------
2897: ** Alice | 43
2898: ** Bob | 28
2899: ** Cindy | 21
2900: ** </pre></blockquote>
2901: **
2902: ** There are two columns (M==2) and three rows (N==3). Thus the
2903: ** result table has 8 entries. Suppose the result table is stored
2904: ** in an array named azResult. Then azResult holds this content:
2905: **
2906: ** <blockquote><pre>
2907: ** azResult[0] = "Name";
2908: ** azResult[1] = "Age";
2909: ** azResult[2] = "Alice";
2910: ** azResult[3] = "43";
2911: ** azResult[4] = "Bob";
2912: ** azResult[5] = "28";
2913: ** azResult[6] = "Cindy";
2914: ** azResult[7] = "21";
2915: ** </pre></blockquote>)^
2916: **
2917: ** ^The sqlite3_get_table() function evaluates one or more
2918: ** semicolon-separated SQL statements in the zero-terminated UTF-8
2919: ** string of its 2nd parameter and returns a result table to the
2920: ** pointer given in its 3rd parameter.
2921: **
2922: ** After the application has finished with the result from sqlite3_get_table(),
2923: ** it must pass the result table pointer to sqlite3_free_table() in order to
2924: ** release the memory that was malloced. Because of the way the
2925: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2926: ** function must not try to call [sqlite3_free()] directly. Only
2927: ** [sqlite3_free_table()] is able to release the memory properly and safely.
2928: **
2929: ** The sqlite3_get_table() interface is implemented as a wrapper around
2930: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2931: ** to any internal data structures of SQLite. It uses only the public
2932: ** interface defined here. As a consequence, errors that occur in the
2933: ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2934: ** reflected in subsequent calls to [sqlite3_errcode()] or
2935: ** [sqlite3_errmsg()].
2936: */
2937: SQLITE_API int sqlite3_get_table(
2938: sqlite3 *db, /* An open database */
2939: const char *zSql, /* SQL to be evaluated */
2940: char ***pazResult, /* Results of the query */
2941: int *pnRow, /* Number of result rows written here */
2942: int *pnColumn, /* Number of result columns written here */
2943: char **pzErrmsg /* Error msg written here */
2944: );
2945: SQLITE_API void sqlite3_free_table(char **result);
2946:
2947: /*
2948: ** CAPI3REF: Formatted String Printing Functions
2949: **
2950: ** These routines are work-alikes of the "printf()" family of functions
2951: ** from the standard C library.
2952: ** These routines understand most of the common formatting options from
2953: ** the standard library printf()
2954: ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2955: ** See the [built-in printf()] documentation for details.
2956: **
2957: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2958: ** results into memory obtained from [sqlite3_malloc64()].
2959: ** The strings returned by these two routines should be
2960: ** released by [sqlite3_free()]. ^Both routines return a
2961: ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2962: ** memory to hold the resulting string.
2963: **
2964: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2965: ** the standard C library. The result is written into the
2966: ** buffer supplied as the second parameter whose size is given by
2967: ** the first parameter. Note that the order of the
2968: ** first two parameters is reversed from snprintf().)^ This is an
2969: ** historical accident that cannot be fixed without breaking
2970: ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2971: ** returns a pointer to its buffer instead of the number of
2972: ** characters actually written into the buffer.)^ We admit that
2973: ** the number of characters written would be a more useful return
2974: ** value but we cannot change the implementation of sqlite3_snprintf()
2975: ** now without breaking compatibility.
2976: **
2977: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2978: ** guarantees that the buffer is always zero-terminated. ^The first
2979: ** parameter "n" is the total size of the buffer, including space for
2980: ** the zero terminator. So the longest string that can be completely
2981: ** written will be n-1 characters.
2982: **
2983: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2984: **
2985: ** See also: [built-in printf()], [printf() SQL function]
2986: */
2987: SQLITE_API char *sqlite3_mprintf(const char*,...);
2988: SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2989: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2990: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2991:
2992: /*
2993: ** CAPI3REF: Memory Allocation Subsystem
2994: **
2995: ** The SQLite core uses these three routines for all of its own
2996: ** internal memory allocation needs. "Core" in the previous sentence
2997: ** does not include operating-system specific [VFS] implementation. The
2998: ** Windows VFS uses native malloc() and free() for some operations.
2999: **
3000: ** ^The sqlite3_malloc() routine returns a pointer to a block
3001: ** of memory at least N bytes in length, where N is the parameter.
3002: ** ^If sqlite3_malloc() is unable to obtain sufficient free
3003: ** memory, it returns a NULL pointer. ^If the parameter N to
3004: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3005: ** a NULL pointer.
3006: **
3007: ** ^The sqlite3_malloc64(N) routine works just like
3008: ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3009: ** of a signed 32-bit integer.
3010: **
3011: ** ^Calling sqlite3_free() with a pointer previously returned
3012: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3013: ** that it might be reused. ^The sqlite3_free() routine is
3014: ** a no-op if is called with a NULL pointer. Passing a NULL pointer
3015: ** to sqlite3_free() is harmless. After being freed, memory
3016: ** should neither be read nor written. Even reading previously freed
3017: ** memory might result in a segmentation fault or other severe error.
3018: ** Memory corruption, a segmentation fault, or other severe error
3019: ** might result if sqlite3_free() is called with a non-NULL pointer that
3020: ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3021: **
3022: ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3023: ** prior memory allocation X to be at least N bytes.
3024: ** ^If the X parameter to sqlite3_realloc(X,N)
3025: ** is a NULL pointer then its behavior is identical to calling
3026: ** sqlite3_malloc(N).
3027: ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3028: ** negative then the behavior is exactly the same as calling
3029: ** sqlite3_free(X).
3030: ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3031: ** of at least N bytes in size or NULL if insufficient memory is available.
3032: ** ^If M is the size of the prior allocation, then min(N,M) bytes
3033: ** of the prior allocation are copied into the beginning of buffer returned
3034: ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3035: ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3036: ** prior allocation is not freed.
3037: **
3038: ** ^The sqlite3_realloc64(X,N) interfaces works the same as
3039: ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3040: ** of a 32-bit signed integer.
3041: **
3042: ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3043: ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3044: ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3045: ** ^The value returned by sqlite3_msize(X) might be larger than the number
3046: ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3047: ** sqlite3_msize(X) returns zero. If X points to something that is not
3048: ** the beginning of memory allocation, or if it points to a formerly
3049: ** valid memory allocation that has now been freed, then the behavior
3050: ** of sqlite3_msize(X) is undefined and possibly harmful.
3051: **
3052: ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3053: ** sqlite3_malloc64(), and sqlite3_realloc64()
3054: ** is always aligned to at least an 8 byte boundary, or to a
3055: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3056: ** option is used.
3057: **
3058: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3059: ** must be either NULL or else pointers obtained from a prior
3060: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3061: ** not yet been released.
3062: **
3063: ** The application must not read or write any part of
3064: ** a block of memory after it has been released using
3065: ** [sqlite3_free()] or [sqlite3_realloc()].
3066: */
3067: SQLITE_API void *sqlite3_malloc(int);
3068: SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3069: SQLITE_API void *sqlite3_realloc(void*, int);
3070: SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3071: SQLITE_API void sqlite3_free(void*);
3072: SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3073:
3074: /*
3075: ** CAPI3REF: Memory Allocator Statistics
3076: **
3077: ** SQLite provides these two interfaces for reporting on the status
3078: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3079: ** routines, which form the built-in memory allocation subsystem.
3080: **
3081: ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3082: ** of memory currently outstanding (malloced but not freed).
3083: ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3084: ** value of [sqlite3_memory_used()] since the high-water mark
3085: ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3086: ** [sqlite3_memory_highwater()] include any overhead
3087: ** added by SQLite in its implementation of [sqlite3_malloc()],
3088: ** but not overhead added by the any underlying system library
3089: ** routines that [sqlite3_malloc()] may call.
3090: **
3091: ** ^The memory high-water mark is reset to the current value of
3092: ** [sqlite3_memory_used()] if and only if the parameter to
3093: ** [sqlite3_memory_highwater()] is true. ^The value returned
3094: ** by [sqlite3_memory_highwater(1)] is the high-water mark
3095: ** prior to the reset.
3096: */
3097: SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3098: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3099:
3100: /*
3101: ** CAPI3REF: Pseudo-Random Number Generator
3102: **
3103: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3104: ** select random [ROWID | ROWIDs] when inserting new records into a table that
3105: ** already uses the largest possible [ROWID]. The PRNG is also used for
3106: ** the built-in random() and randomblob() SQL functions. This interface allows
3107: ** applications to access the same PRNG for other purposes.
3108: **
3109: ** ^A call to this routine stores N bytes of randomness into buffer P.
3110: ** ^The P parameter can be a NULL pointer.
3111: **
3112: ** ^If this routine has not been previously called or if the previous
3113: ** call had N less than one or a NULL pointer for P, then the PRNG is
3114: ** seeded using randomness obtained from the xRandomness method of
3115: ** the default [sqlite3_vfs] object.
3116: ** ^If the previous call to this routine had an N of 1 or more and a
3117: ** non-NULL P then the pseudo-randomness is generated
3118: ** internally and without recourse to the [sqlite3_vfs] xRandomness
3119: ** method.
3120: */
3121: SQLITE_API void sqlite3_randomness(int N, void *P);
3122:
3123: /*
3124: ** CAPI3REF: Compile-Time Authorization Callbacks
3125: ** METHOD: sqlite3
3126: ** KEYWORDS: {authorizer callback}
3127: **
3128: ** ^This routine registers an authorizer callback with a particular
3129: ** [database connection], supplied in the first argument.
3130: ** ^The authorizer callback is invoked as SQL statements are being compiled
3131: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3132: ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3133: ** and [sqlite3_prepare16_v3()]. ^At various
3134: ** points during the compilation process, as logic is being created
3135: ** to perform various actions, the authorizer callback is invoked to
3136: ** see if those actions are allowed. ^The authorizer callback should
3137: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3138: ** specific action but allow the SQL statement to continue to be
3139: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3140: ** rejected with an error. ^If the authorizer callback returns
3141: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3142: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3143: ** the authorizer will fail with an error message.
3144: **
3145: ** When the callback returns [SQLITE_OK], that means the operation
3146: ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3147: ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3148: ** authorizer will fail with an error message explaining that
3149: ** access is denied.
3150: **
3151: ** ^The first parameter to the authorizer callback is a copy of the third
3152: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3153: ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3154: ** the particular action to be authorized. ^The third through sixth parameters
3155: ** to the callback are either NULL pointers or zero-terminated strings
3156: ** that contain additional details about the action to be authorized.
3157: ** Applications must always be prepared to encounter a NULL pointer in any
3158: ** of the third through the sixth parameters of the authorization callback.
3159: **
3160: ** ^If the action code is [SQLITE_READ]
3161: ** and the callback returns [SQLITE_IGNORE] then the
3162: ** [prepared statement] statement is constructed to substitute
3163: ** a NULL value in place of the table column that would have
3164: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3165: ** return can be used to deny an untrusted user access to individual
3166: ** columns of a table.
3167: ** ^When a table is referenced by a [SELECT] but no column values are
3168: ** extracted from that table (for example in a query like
3169: ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3170: ** is invoked once for that table with a column name that is an empty string.
3171: ** ^If the action code is [SQLITE_DELETE] and the callback returns
3172: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3173: ** [truncate optimization] is disabled and all rows are deleted individually.
3174: **
3175: ** An authorizer is used when [sqlite3_prepare | preparing]
3176: ** SQL statements from an untrusted source, to ensure that the SQL statements
3177: ** do not try to access data they are not allowed to see, or that they do not
3178: ** try to execute malicious statements that damage the database. For
3179: ** example, an application may allow a user to enter arbitrary
3180: ** SQL queries for evaluation by a database. But the application does
3181: ** not want the user to be able to make arbitrary changes to the
3182: ** database. An authorizer could then be put in place while the
3183: ** user-entered SQL is being [sqlite3_prepare | prepared] that
3184: ** disallows everything except [SELECT] statements.
3185: **
3186: ** Applications that need to process SQL from untrusted sources
3187: ** might also consider lowering resource limits using [sqlite3_limit()]
3188: ** and limiting database size using the [max_page_count] [PRAGMA]
3189: ** in addition to using an authorizer.
3190: **
3191: ** ^(Only a single authorizer can be in place on a database connection
3192: ** at a time. Each call to sqlite3_set_authorizer overrides the
3193: ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3194: ** The authorizer is disabled by default.
3195: **
3196: ** The authorizer callback must not do anything that will modify
3197: ** the database connection that invoked the authorizer callback.
3198: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3199: ** database connections for the meaning of "modify" in this paragraph.
3200: **
3201: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3202: ** statement might be re-prepared during [sqlite3_step()] due to a
3203: ** schema change. Hence, the application should ensure that the
3204: ** correct authorizer callback remains in place during the [sqlite3_step()].
3205: **
3206: ** ^Note that the authorizer callback is invoked only during
3207: ** [sqlite3_prepare()] or its variants. Authorization is not
3208: ** performed during statement evaluation in [sqlite3_step()], unless
3209: ** as stated in the previous paragraph, sqlite3_step() invokes
3210: ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3211: */
3212: SQLITE_API int sqlite3_set_authorizer(
3213: sqlite3*,
3214: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3215: void *pUserData
3216: );
3217:
3218: /*
3219: ** CAPI3REF: Authorizer Return Codes
3220: **
3221: ** The [sqlite3_set_authorizer | authorizer callback function] must
3222: ** return either [SQLITE_OK] or one of these two constants in order
3223: ** to signal SQLite whether or not the action is permitted. See the
3224: ** [sqlite3_set_authorizer | authorizer documentation] for additional
3225: ** information.
3226: **
3227: ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3228: ** returned from the [sqlite3_vtab_on_conflict()] interface.
3229: */
3230: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3231: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3232:
3233: /*
3234: ** CAPI3REF: Authorizer Action Codes
3235: **
3236: ** The [sqlite3_set_authorizer()] interface registers a callback function
3237: ** that is invoked to authorize certain SQL statement actions. The
3238: ** second parameter to the callback is an integer code that specifies
3239: ** what action is being authorized. These are the integer action codes that
3240: ** the authorizer callback may be passed.
3241: **
3242: ** These action code values signify what kind of operation is to be
3243: ** authorized. The 3rd and 4th parameters to the authorization
3244: ** callback function will be parameters or NULL depending on which of these
3245: ** codes is used as the second parameter. ^(The 5th parameter to the
3246: ** authorizer callback is the name of the database ("main", "temp",
3247: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3248: ** is the name of the inner-most trigger or view that is responsible for
3249: ** the access attempt or NULL if this access attempt is directly from
3250: ** top-level SQL code.
3251: */
3252: /******************************************* 3rd ************ 4th ***********/
3253: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3254: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3255: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3256: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3257: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3258: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3259: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3260: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3261: #define SQLITE_DELETE 9 /* Table Name NULL */
3262: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3263: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3264: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3265: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3266: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3267: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3268: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3269: #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3270: #define SQLITE_INSERT 18 /* Table Name NULL */
3271: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3272: #define SQLITE_READ 20 /* Table Name Column Name */
3273: #define SQLITE_SELECT 21 /* NULL NULL */
3274: #define SQLITE_TRANSACTION 22 /* Operation NULL */
3275: #define SQLITE_UPDATE 23 /* Table Name Column Name */
3276: #define SQLITE_ATTACH 24 /* Filename NULL */
3277: #define SQLITE_DETACH 25 /* Database Name NULL */
3278: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3279: #define SQLITE_REINDEX 27 /* Index Name NULL */
3280: #define SQLITE_ANALYZE 28 /* Table Name NULL */
3281: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3282: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3283: #define SQLITE_FUNCTION 31 /* NULL Function Name */
3284: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3285: #define SQLITE_COPY 0 /* No longer used */
3286: #define SQLITE_RECURSIVE 33 /* NULL NULL */
3287:
3288: /*
3289: ** CAPI3REF: Tracing And Profiling Functions
3290: ** METHOD: sqlite3
3291: **
3292: ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3293: ** instead of the routines described here.
3294: **
3295: ** These routines register callback functions that can be used for
3296: ** tracing and profiling the execution of SQL statements.
3297: **
3298: ** ^The callback function registered by sqlite3_trace() is invoked at
3299: ** various times when an SQL statement is being run by [sqlite3_step()].
3300: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3301: ** SQL statement text as the statement first begins executing.
3302: ** ^(Additional sqlite3_trace() callbacks might occur
3303: ** as each triggered subprogram is entered. The callbacks for triggers
3304: ** contain a UTF-8 SQL comment that identifies the trigger.)^
3305: **
3306: ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3307: ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3308: **
3309: ** ^The callback function registered by sqlite3_profile() is invoked
3310: ** as each SQL statement finishes. ^The profile callback contains
3311: ** the original statement text and an estimate of wall-clock time
3312: ** of how long that statement took to run. ^The profile callback
3313: ** time is in units of nanoseconds, however the current implementation
3314: ** is only capable of millisecond resolution so the six least significant
3315: ** digits in the time are meaningless. Future versions of SQLite
3316: ** might provide greater resolution on the profiler callback. Invoking
3317: ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3318: ** profile callback.
3319: */
3320: SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3321: void(*xTrace)(void*,const char*), void*);
3322: SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3323: void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3324:
3325: /*
3326: ** CAPI3REF: SQL Trace Event Codes
3327: ** KEYWORDS: SQLITE_TRACE
3328: **
3329: ** These constants identify classes of events that can be monitored
3330: ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3331: ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3332: ** the following constants. ^The first argument to the trace callback
3333: ** is one of the following constants.
3334: **
3335: ** New tracing constants may be added in future releases.
3336: **
3337: ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3338: ** ^The T argument is one of the integer type codes above.
3339: ** ^The C argument is a copy of the context pointer passed in as the
3340: ** fourth argument to [sqlite3_trace_v2()].
3341: ** The P and X arguments are pointers whose meanings depend on T.
3342: **
3343: ** <dl>
3344: ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3345: ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3346: ** first begins running and possibly at other times during the
3347: ** execution of the prepared statement, such as at the start of each
3348: ** trigger subprogram. ^The P argument is a pointer to the
3349: ** [prepared statement]. ^The X argument is a pointer to a string which
3350: ** is the unexpanded SQL text of the prepared statement or an SQL comment
3351: ** that indicates the invocation of a trigger. ^The callback can compute
3352: ** the same text that would have been returned by the legacy [sqlite3_trace()]
3353: ** interface by using the X argument when X begins with "--" and invoking
3354: ** [sqlite3_expanded_sql(P)] otherwise.
3355: **
3356: ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3357: ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3358: ** information as is provided by the [sqlite3_profile()] callback.
3359: ** ^The P argument is a pointer to the [prepared statement] and the
3360: ** X argument points to a 64-bit integer which is approximately
3361: ** the number of nanoseconds that the prepared statement took to run.
3362: ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3363: **
3364: ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3365: ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3366: ** statement generates a single row of result.
3367: ** ^The P argument is a pointer to the [prepared statement] and the
3368: ** X argument is unused.
3369: **
3370: ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3371: ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3372: ** connection closes.
3373: ** ^The P argument is a pointer to the [database connection] object
3374: ** and the X argument is unused.
3375: ** </dl>
3376: */
3377: #define SQLITE_TRACE_STMT 0x01
3378: #define SQLITE_TRACE_PROFILE 0x02
3379: #define SQLITE_TRACE_ROW 0x04
3380: #define SQLITE_TRACE_CLOSE 0x08
3381:
3382: /*
3383: ** CAPI3REF: SQL Trace Hook
3384: ** METHOD: sqlite3
3385: **
3386: ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3387: ** function X against [database connection] D, using property mask M
3388: ** and context pointer P. ^If the X callback is
3389: ** NULL or if the M mask is zero, then tracing is disabled. The
3390: ** M argument should be the bitwise OR-ed combination of
3391: ** zero or more [SQLITE_TRACE] constants.
3392: **
3393: ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3394: ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3395: ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3396: ** database connection may have at most one trace callback.
3397: **
3398: ** ^The X callback is invoked whenever any of the events identified by
3399: ** mask M occur. ^The integer return value from the callback is currently
3400: ** ignored, though this may change in future releases. Callback
3401: ** implementations should return zero to ensure future compatibility.
3402: **
3403: ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3404: ** ^The T argument is one of the [SQLITE_TRACE]
3405: ** constants to indicate why the callback was invoked.
3406: ** ^The C argument is a copy of the context pointer.
3407: ** The P and X arguments are pointers whose meanings depend on T.
3408: **
3409: ** The sqlite3_trace_v2() interface is intended to replace the legacy
3410: ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3411: ** are deprecated.
3412: */
3413: SQLITE_API int sqlite3_trace_v2(
3414: sqlite3*,
3415: unsigned uMask,
3416: int(*xCallback)(unsigned,void*,void*,void*),
3417: void *pCtx
3418: );
3419:
3420: /*
3421: ** CAPI3REF: Query Progress Callbacks
3422: ** METHOD: sqlite3
3423: **
3424: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3425: ** function X to be invoked periodically during long running calls to
3426: ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3427: ** database connection D. An example use for this
3428: ** interface is to keep a GUI updated during a large query.
3429: **
3430: ** ^The parameter P is passed through as the only parameter to the
3431: ** callback function X. ^The parameter N is the approximate number of
3432: ** [virtual machine instructions] that are evaluated between successive
3433: ** invocations of the callback X. ^If N is less than one then the progress
3434: ** handler is disabled.
3435: **
3436: ** ^Only a single progress handler may be defined at one time per
3437: ** [database connection]; setting a new progress handler cancels the
3438: ** old one. ^Setting parameter X to NULL disables the progress handler.
3439: ** ^The progress handler is also disabled by setting N to a value less
3440: ** than 1.
3441: **
3442: ** ^If the progress callback returns non-zero, the operation is
3443: ** interrupted. This feature can be used to implement a
3444: ** "Cancel" button on a GUI progress dialog box.
3445: **
3446: ** The progress handler callback must not do anything that will modify
3447: ** the database connection that invoked the progress handler.
3448: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3449: ** database connections for the meaning of "modify" in this paragraph.
3450: **
3451: ** The progress handler callback would originally only be invoked from the
3452: ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3453: ** and similar because those routines might force a reparse of the schema
3454: ** which involves running the bytecode engine. However, beginning with
3455: ** SQLite version 3.41.0, the progress handler callback might also be
3456: ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3457: ** code for complex queries.
3458: */
3459: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3460:
3461: /*
3462: ** CAPI3REF: Opening A New Database Connection
3463: ** CONSTRUCTOR: sqlite3
3464: **
3465: ** ^These routines open an SQLite database file as specified by the
3466: ** filename argument. ^The filename argument is interpreted as UTF-8 for
3467: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3468: ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3469: ** returned in *ppDb, even if an error occurs. The only exception is that
3470: ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3471: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3472: ** object.)^ ^(If the database is opened (and/or created) successfully, then
3473: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3474: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3475: ** an English language description of the error following a failure of any
3476: ** of the sqlite3_open() routines.
3477: **
3478: ** ^The default encoding will be UTF-8 for databases created using
3479: ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3480: ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3481: **
3482: ** Whether or not an error occurs when it is opened, resources
3483: ** associated with the [database connection] handle should be released by
3484: ** passing it to [sqlite3_close()] when it is no longer required.
3485: **
3486: ** The sqlite3_open_v2() interface works like sqlite3_open()
3487: ** except that it accepts two additional parameters for additional control
3488: ** over the new database connection. ^(The flags parameter to
3489: ** sqlite3_open_v2() must include, at a minimum, one of the following
3490: ** three flag combinations:)^
3491: **
3492: ** <dl>
3493: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3494: ** <dd>The database is opened in read-only mode. If the database does
3495: ** not already exist, an error is returned.</dd>)^
3496: **
3497: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3498: ** <dd>The database is opened for reading and writing if possible, or
3499: ** reading only if the file is write protected by the operating
3500: ** system. In either case the database must already exist, otherwise
3501: ** an error is returned. For historical reasons, if opening in
3502: ** read-write mode fails due to OS-level permissions, an attempt is
3503: ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3504: ** used to determine whether the database is actually
3505: ** read-write.</dd>)^
3506: **
3507: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3508: ** <dd>The database is opened for reading and writing, and is created if
3509: ** it does not already exist. This is the behavior that is always used for
3510: ** sqlite3_open() and sqlite3_open16().</dd>)^
3511: ** </dl>
3512: **
3513: ** In addition to the required flags, the following optional flags are
3514: ** also supported:
3515: **
3516: ** <dl>
3517: ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3518: ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3519: **
3520: ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3521: ** <dd>The database will be opened as an in-memory database. The database
3522: ** is named by the "filename" argument for the purposes of cache-sharing,
3523: ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3524: ** </dd>)^
3525: **
3526: ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3527: ** <dd>The new database connection will use the "multi-thread"
3528: ** [threading mode].)^ This means that separate threads are allowed
3529: ** to use SQLite at the same time, as long as each thread is using
3530: ** a different [database connection].
3531: **
3532: ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3533: ** <dd>The new database connection will use the "serialized"
3534: ** [threading mode].)^ This means the multiple threads can safely
3535: ** attempt to use the same database connection at the same time.
3536: ** (Mutexes will block any actual concurrency, but in this mode
3537: ** there is no harm in trying.)
3538: **
3539: ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3540: ** <dd>The database is opened [shared cache] enabled, overriding
3541: ** the default shared cache setting provided by
3542: ** [sqlite3_enable_shared_cache()].)^
3543: ** The [use of shared cache mode is discouraged] and hence shared cache
3544: ** capabilities may be omitted from many builds of SQLite. In such cases,
3545: ** this option is a no-op.
3546: **
3547: ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3548: ** <dd>The database is opened [shared cache] disabled, overriding
3549: ** the default shared cache setting provided by
3550: ** [sqlite3_enable_shared_cache()].)^
3551: **
3552: ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3553: ** <dd>The database connection comes up in "extended result code mode".
3554: ** In other words, the database behaves has if
3555: ** [sqlite3_extended_result_codes(db,1)] where called on the database
3556: ** connection as soon as the connection is created. In addition to setting
3557: ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3558: ** to return an extended result code.</dd>
3559: **
3560: ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3561: ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3562: ** </dl>)^
3563: **
3564: ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3565: ** required combinations shown above optionally combined with other
3566: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3567: ** then the behavior is undefined. Historic versions of SQLite
3568: ** have silently ignored surplus bits in the flags parameter to
3569: ** sqlite3_open_v2(), however that behavior might not be carried through
3570: ** into future versions of SQLite and so applications should not rely
3571: ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3572: ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3573: ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3574: ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3575: ** by sqlite3_open_v2().
3576: **
3577: ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3578: ** [sqlite3_vfs] object that defines the operating system interface that
3579: ** the new database connection should use. ^If the fourth parameter is
3580: ** a NULL pointer then the default [sqlite3_vfs] object is used.
3581: **
3582: ** ^If the filename is ":memory:", then a private, temporary in-memory database
3583: ** is created for the connection. ^This in-memory database will vanish when
3584: ** the database connection is closed. Future versions of SQLite might
3585: ** make use of additional special filenames that begin with the ":" character.
3586: ** It is recommended that when a database filename actually does begin with
3587: ** a ":" character you should prefix the filename with a pathname such as
3588: ** "./" to avoid ambiguity.
3589: **
3590: ** ^If the filename is an empty string, then a private, temporary
3591: ** on-disk database will be created. ^This private database will be
3592: ** automatically deleted as soon as the database connection is closed.
3593: **
3594: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3595: **
3596: ** ^If [URI filename] interpretation is enabled, and the filename argument
3597: ** begins with "file:", then the filename is interpreted as a URI. ^URI
3598: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3599: ** set in the third argument to sqlite3_open_v2(), or if it has
3600: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3601: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3602: ** URI filename interpretation is turned off
3603: ** by default, but future releases of SQLite might enable URI filename
3604: ** interpretation by default. See "[URI filenames]" for additional
3605: ** information.
3606: **
3607: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3608: ** authority, then it must be either an empty string or the string
3609: ** "localhost". ^If the authority is not an empty string or "localhost", an
3610: ** error is returned to the caller. ^The fragment component of a URI, if
3611: ** present, is ignored.
3612: **
3613: ** ^SQLite uses the path component of the URI as the name of the disk file
3614: ** which contains the database. ^If the path begins with a '/' character,
3615: ** then it is interpreted as an absolute path. ^If the path does not begin
3616: ** with a '/' (meaning that the authority section is omitted from the URI)
3617: ** then the path is interpreted as a relative path.
3618: ** ^(On windows, the first component of an absolute path
3619: ** is a drive specification (e.g. "C:").)^
3620: **
3621: ** [[core URI query parameters]]
3622: ** The query component of a URI may contain parameters that are interpreted
3623: ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3624: ** SQLite and its built-in [VFSes] interpret the
3625: ** following query parameters:
3626: **
3627: ** <ul>
3628: ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3629: ** a VFS object that provides the operating system interface that should
3630: ** be used to access the database file on disk. ^If this option is set to
3631: ** an empty string the default VFS object is used. ^Specifying an unknown
3632: ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3633: ** present, then the VFS specified by the option takes precedence over
3634: ** the value passed as the fourth parameter to sqlite3_open_v2().
3635: **
3636: ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3637: ** "rwc", or "memory". Attempting to set it to any other value is
3638: ** an error)^.
3639: ** ^If "ro" is specified, then the database is opened for read-only
3640: ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3641: ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3642: ** "rw", then the database is opened for read-write (but not create)
3643: ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3644: ** been set. ^Value "rwc" is equivalent to setting both
3645: ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3646: ** set to "memory" then a pure [in-memory database] that never reads
3647: ** or writes from disk is used. ^It is an error to specify a value for
3648: ** the mode parameter that is less restrictive than that specified by
3649: ** the flags passed in the third parameter to sqlite3_open_v2().
3650: **
3651: ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3652: ** "private". ^Setting it to "shared" is equivalent to setting the
3653: ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3654: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3655: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3656: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3657: ** a URI filename, its value overrides any behavior requested by setting
3658: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3659: **
3660: ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3661: ** [powersafe overwrite] property does or does not apply to the
3662: ** storage media on which the database file resides.
3663: **
3664: ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3665: ** which if set disables file locking in rollback journal modes. This
3666: ** is useful for accessing a database on a filesystem that does not
3667: ** support locking. Caution: Database corruption might result if two
3668: ** or more processes write to the same database and any one of those
3669: ** processes uses nolock=1.
3670: **
3671: ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3672: ** parameter that indicates that the database file is stored on
3673: ** read-only media. ^When immutable is set, SQLite assumes that the
3674: ** database file cannot be changed, even by a process with higher
3675: ** privilege, and so the database is opened read-only and all locking
3676: ** and change detection is disabled. Caution: Setting the immutable
3677: ** property on a database file that does in fact change can result
3678: ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3679: ** See also: [SQLITE_IOCAP_IMMUTABLE].
3680: **
3681: ** </ul>
3682: **
3683: ** ^Specifying an unknown parameter in the query component of a URI is not an
3684: ** error. Future versions of SQLite might understand additional query
3685: ** parameters. See "[query parameters with special meaning to SQLite]" for
3686: ** additional information.
3687: **
3688: ** [[URI filename examples]] <h3>URI filename examples</h3>
3689: **
3690: ** <table border="1" align=center cellpadding=5>
3691: ** <tr><th> URI filenames <th> Results
3692: ** <tr><td> file:data.db <td>
3693: ** Open the file "data.db" in the current directory.
3694: ** <tr><td> file:/home/fred/data.db<br>
3695: ** file:///home/fred/data.db <br>
3696: ** file://localhost/home/fred/data.db <br> <td>
3697: ** Open the database file "/home/fred/data.db".
3698: ** <tr><td> file://darkstar/home/fred/data.db <td>
3699: ** An error. "darkstar" is not a recognized authority.
3700: ** <tr><td style="white-space:nowrap">
3701: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3702: ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3703: ** C:. Note that the %20 escaping in this example is not strictly
3704: ** necessary - space characters can be used literally
3705: ** in URI filenames.
3706: ** <tr><td> file:data.db?mode=ro&cache=private <td>
3707: ** Open file "data.db" in the current directory for read-only access.
3708: ** Regardless of whether or not shared-cache mode is enabled by
3709: ** default, use a private cache.
3710: ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3711: ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3712: ** that uses dot-files in place of posix advisory locking.
3713: ** <tr><td> file:data.db?mode=readonly <td>
3714: ** An error. "readonly" is not a valid option for the "mode" parameter.
3715: ** Use "ro" instead: "file:data.db?mode=ro".
3716: ** </table>
3717: **
3718: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3719: ** query components of a URI. A hexadecimal escape sequence consists of a
3720: ** percent sign - "%" - followed by exactly two hexadecimal digits
3721: ** specifying an octet value. ^Before the path or query components of a
3722: ** URI filename are interpreted, they are encoded using UTF-8 and all
3723: ** hexadecimal escape sequences replaced by a single byte containing the
3724: ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3725: ** the results are undefined.
3726: **
3727: ** <b>Note to Windows users:</b> The encoding used for the filename argument
3728: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3729: ** codepage is currently defined. Filenames containing international
3730: ** characters must be converted to UTF-8 prior to passing them into
3731: ** sqlite3_open() or sqlite3_open_v2().
3732: **
3733: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3734: ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3735: ** features that require the use of temporary files may fail.
3736: **
3737: ** See also: [sqlite3_temp_directory]
3738: */
3739: SQLITE_API int sqlite3_open(
3740: const char *filename, /* Database filename (UTF-8) */
3741: sqlite3 **ppDb /* OUT: SQLite db handle */
3742: );
3743: SQLITE_API int sqlite3_open16(
3744: const void *filename, /* Database filename (UTF-16) */
3745: sqlite3 **ppDb /* OUT: SQLite db handle */
3746: );
3747: SQLITE_API int sqlite3_open_v2(
3748: const char *filename, /* Database filename (UTF-8) */
3749: sqlite3 **ppDb, /* OUT: SQLite db handle */
3750: int flags, /* Flags */
3751: const char *zVfs /* Name of VFS module to use */
3752: );
3753:
3754: /*
3755: ** CAPI3REF: Obtain Values For URI Parameters
3756: **
3757: ** These are utility routines, useful to [VFS|custom VFS implementations],
3758: ** that check if a database file was a URI that contained a specific query
3759: ** parameter, and if so obtains the value of that query parameter.
3760: **
3761: ** The first parameter to these interfaces (hereafter referred to
3762: ** as F) must be one of:
3763: ** <ul>
3764: ** <li> A database filename pointer created by the SQLite core and
3765: ** passed into the xOpen() method of a VFS implementation, or
3766: ** <li> A filename obtained from [sqlite3_db_filename()], or
3767: ** <li> A new filename constructed using [sqlite3_create_filename()].
3768: ** </ul>
3769: ** If the F parameter is not one of the above, then the behavior is
3770: ** undefined and probably undesirable. Older versions of SQLite were
3771: ** more tolerant of invalid F parameters than newer versions.
3772: **
3773: ** If F is a suitable filename (as described in the previous paragraph)
3774: ** and if P is the name of the query parameter, then
3775: ** sqlite3_uri_parameter(F,P) returns the value of the P
3776: ** parameter if it exists or a NULL pointer if P does not appear as a
3777: ** query parameter on F. If P is a query parameter of F and it
3778: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3779: ** a pointer to an empty string.
3780: **
3781: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3782: ** parameter and returns true (1) or false (0) according to the value
3783: ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3784: ** value of query parameter P is one of "yes", "true", or "on" in any
3785: ** case or if the value begins with a non-zero number. The
3786: ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3787: ** query parameter P is one of "no", "false", or "off" in any case or
3788: ** if the value begins with a numeric zero. If P is not a query
3789: ** parameter on F or if the value of P does not match any of the
3790: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3791: **
3792: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3793: ** 64-bit signed integer and returns that integer, or D if P does not
3794: ** exist. If the value of P is something other than an integer, then
3795: ** zero is returned.
3796: **
3797: ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3798: ** the value) of the N-th query parameter for filename F, or a NULL
3799: ** pointer if N is less than zero or greater than the number of query
3800: ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3801: ** the name of the first query parameter, 1 for the second parameter, and
3802: ** so forth.
3803: **
3804: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3805: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3806: ** is not a database file pathname pointer that the SQLite core passed
3807: ** into the xOpen VFS method, then the behavior of this routine is undefined
3808: ** and probably undesirable.
3809: **
3810: ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3811: ** parameter can also be the name of a rollback journal file or WAL file
3812: ** in addition to the main database file. Prior to version 3.31.0, these
3813: ** routines would only work if F was the name of the main database file.
3814: ** When the F parameter is the name of the rollback journal or WAL file,
3815: ** it has access to all the same query parameters as were found on the
3816: ** main database file.
3817: **
3818: ** See the [URI filename] documentation for additional information.
3819: */
3820: SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3821: SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3822: SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3823: SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3824:
3825: /*
3826: ** CAPI3REF: Translate filenames
3827: **
3828: ** These routines are available to [VFS|custom VFS implementations] for
3829: ** translating filenames between the main database file, the journal file,
3830: ** and the WAL file.
3831: **
3832: ** If F is the name of an sqlite database file, journal file, or WAL file
3833: ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3834: ** returns the name of the corresponding database file.
3835: **
3836: ** If F is the name of an sqlite database file, journal file, or WAL file
3837: ** passed by the SQLite core into the VFS, or if F is a database filename
3838: ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3839: ** returns the name of the corresponding rollback journal file.
3840: **
3841: ** If F is the name of an sqlite database file, journal file, or WAL file
3842: ** that was passed by the SQLite core into the VFS, or if F is a database
3843: ** filename obtained from [sqlite3_db_filename()], then
3844: ** sqlite3_filename_wal(F) returns the name of the corresponding
3845: ** WAL file.
3846: **
3847: ** In all of the above, if F is not the name of a database, journal or WAL
3848: ** filename passed into the VFS from the SQLite core and F is not the
3849: ** return value from [sqlite3_db_filename()], then the result is
3850: ** undefined and is likely a memory access violation.
3851: */
3852: SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3853: SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3854: SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3855:
3856: /*
3857: ** CAPI3REF: Database File Corresponding To A Journal
3858: **
3859: ** ^If X is the name of a rollback or WAL-mode journal file that is
3860: ** passed into the xOpen method of [sqlite3_vfs], then
3861: ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3862: ** object that represents the main database file.
3863: **
3864: ** This routine is intended for use in custom [VFS] implementations
3865: ** only. It is not a general-purpose interface.
3866: ** The argument sqlite3_file_object(X) must be a filename pointer that
3867: ** has been passed into [sqlite3_vfs].xOpen method where the
3868: ** flags parameter to xOpen contains one of the bits
3869: ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3870: ** of this routine results in undefined and probably undesirable
3871: ** behavior.
3872: */
3873: SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3874:
3875: /*
3876: ** CAPI3REF: Create and Destroy VFS Filenames
3877: **
3878: ** These interfaces are provided for use by [VFS shim] implementations and
3879: ** are not useful outside of that context.
3880: **
3881: ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3882: ** database filename D with corresponding journal file J and WAL file W and
3883: ** with N URI parameters key/values pairs in the array P. The result from
3884: ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3885: ** is safe to pass to routines like:
3886: ** <ul>
3887: ** <li> [sqlite3_uri_parameter()],
3888: ** <li> [sqlite3_uri_boolean()],
3889: ** <li> [sqlite3_uri_int64()],
3890: ** <li> [sqlite3_uri_key()],
3891: ** <li> [sqlite3_filename_database()],
3892: ** <li> [sqlite3_filename_journal()], or
3893: ** <li> [sqlite3_filename_wal()].
3894: ** </ul>
3895: ** If a memory allocation error occurs, sqlite3_create_filename() might
3896: ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3897: ** must be released by a corresponding call to sqlite3_free_filename(Y).
3898: **
3899: ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3900: ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3901: ** to a key and value for a query parameter. The P parameter may be a NULL
3902: ** pointer if N is zero. None of the 2*N pointers in the P array may be
3903: ** NULL pointers and key pointers should not be empty strings.
3904: ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3905: ** be NULL pointers, though they can be empty strings.
3906: **
3907: ** The sqlite3_free_filename(Y) routine releases a memory allocation
3908: ** previously obtained from sqlite3_create_filename(). Invoking
3909: ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3910: **
3911: ** If the Y parameter to sqlite3_free_filename(Y) is anything other
3912: ** than a NULL pointer or a pointer previously acquired from
3913: ** sqlite3_create_filename(), then bad things such as heap
3914: ** corruption or segfaults may occur. The value Y should not be
3915: ** used again after sqlite3_free_filename(Y) has been called. This means
3916: ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3917: ** then the corresponding [sqlite3_module.xClose() method should also be
3918: ** invoked prior to calling sqlite3_free_filename(Y).
3919: */
3920: SQLITE_API sqlite3_filename sqlite3_create_filename(
3921: const char *zDatabase,
3922: const char *zJournal,
3923: const char *zWal,
3924: int nParam,
3925: const char **azParam
3926: );
3927: SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3928:
3929: /*
3930: ** CAPI3REF: Error Codes And Messages
3931: ** METHOD: sqlite3
3932: **
3933: ** ^If the most recent sqlite3_* API call associated with
3934: ** [database connection] D failed, then the sqlite3_errcode(D) interface
3935: ** returns the numeric [result code] or [extended result code] for that
3936: ** API call.
3937: ** ^The sqlite3_extended_errcode()
3938: ** interface is the same except that it always returns the
3939: ** [extended result code] even when extended result codes are
3940: ** disabled.
3941: **
3942: ** The values returned by sqlite3_errcode() and/or
3943: ** sqlite3_extended_errcode() might change with each API call.
3944: ** Except, there are some interfaces that are guaranteed to never
3945: ** change the value of the error code. The error-code preserving
3946: ** interfaces include the following:
3947: **
3948: ** <ul>
3949: ** <li> sqlite3_errcode()
3950: ** <li> sqlite3_extended_errcode()
3951: ** <li> sqlite3_errmsg()
3952: ** <li> sqlite3_errmsg16()
3953: ** <li> sqlite3_error_offset()
3954: ** </ul>
3955: **
3956: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3957: ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3958: ** ^(Memory to hold the error message string is managed internally.
3959: ** The application does not need to worry about freeing the result.
3960: ** However, the error string might be overwritten or deallocated by
3961: ** subsequent calls to other SQLite interface functions.)^
3962: **
3963: ** ^The sqlite3_errstr() interface returns the English-language text
3964: ** that describes the [result code], as UTF-8.
3965: ** ^(Memory to hold the error message string is managed internally
3966: ** and must not be freed by the application)^.
3967: **
3968: ** ^If the most recent error references a specific token in the input
3969: ** SQL, the sqlite3_error_offset() interface returns the byte offset
3970: ** of the start of that token. ^The byte offset returned by
3971: ** sqlite3_error_offset() assumes that the input SQL is UTF8.
3972: ** ^If the most recent error does not reference a specific token in the input
3973: ** SQL, then the sqlite3_error_offset() function returns -1.
3974: **
3975: ** When the serialized [threading mode] is in use, it might be the
3976: ** case that a second error occurs on a separate thread in between
3977: ** the time of the first error and the call to these interfaces.
3978: ** When that happens, the second error will be reported since these
3979: ** interfaces always report the most recent result. To avoid
3980: ** this, each thread can obtain exclusive use of the [database connection] D
3981: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3982: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3983: ** all calls to the interfaces listed here are completed.
3984: **
3985: ** If an interface fails with SQLITE_MISUSE, that means the interface
3986: ** was invoked incorrectly by the application. In that case, the
3987: ** error code and message may or may not be set.
3988: */
3989: SQLITE_API int sqlite3_errcode(sqlite3 *db);
3990: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3991: SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3992: SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3993: SQLITE_API const char *sqlite3_errstr(int);
3994: SQLITE_API int sqlite3_error_offset(sqlite3 *db);
3995:
3996: /*
3997: ** CAPI3REF: Prepared Statement Object
3998: ** KEYWORDS: {prepared statement} {prepared statements}
3999: **
4000: ** An instance of this object represents a single SQL statement that
4001: ** has been compiled into binary form and is ready to be evaluated.
4002: **
4003: ** Think of each SQL statement as a separate computer program. The
4004: ** original SQL text is source code. A prepared statement object
4005: ** is the compiled object code. All SQL must be converted into a
4006: ** prepared statement before it can be run.
4007: **
4008: ** The life-cycle of a prepared statement object usually goes like this:
4009: **
4010: ** <ol>
4011: ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4012: ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4013: ** interfaces.
4014: ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4015: ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4016: ** to step 2. Do this zero or more times.
4017: ** <li> Destroy the object using [sqlite3_finalize()].
4018: ** </ol>
4019: */
4020: typedef struct sqlite3_stmt sqlite3_stmt;
4021:
4022: /*
4023: ** CAPI3REF: Run-time Limits
4024: ** METHOD: sqlite3
4025: **
4026: ** ^(This interface allows the size of various constructs to be limited
4027: ** on a connection by connection basis. The first parameter is the
4028: ** [database connection] whose limit is to be set or queried. The
4029: ** second parameter is one of the [limit categories] that define a
4030: ** class of constructs to be size limited. The third parameter is the
4031: ** new limit for that construct.)^
4032: **
4033: ** ^If the new limit is a negative number, the limit is unchanged.
4034: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4035: ** [limits | hard upper bound]
4036: ** set at compile-time by a C preprocessor macro called
4037: ** [limits | SQLITE_MAX_<i>NAME</i>].
4038: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4039: ** ^Attempts to increase a limit above its hard upper bound are
4040: ** silently truncated to the hard upper bound.
4041: **
4042: ** ^Regardless of whether or not the limit was changed, the
4043: ** [sqlite3_limit()] interface returns the prior value of the limit.
4044: ** ^Hence, to find the current value of a limit without changing it,
4045: ** simply invoke this interface with the third parameter set to -1.
4046: **
4047: ** Run-time limits are intended for use in applications that manage
4048: ** both their own internal database and also databases that are controlled
4049: ** by untrusted external sources. An example application might be a
4050: ** web browser that has its own databases for storing history and
4051: ** separate databases controlled by JavaScript applications downloaded
4052: ** off the Internet. The internal databases can be given the
4053: ** large, default limits. Databases managed by external sources can
4054: ** be given much smaller limits designed to prevent a denial of service
4055: ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4056: ** interface to further control untrusted SQL. The size of the database
4057: ** created by an untrusted script can be contained using the
4058: ** [max_page_count] [PRAGMA].
4059: **
4060: ** New run-time limit categories may be added in future releases.
4061: */
4062: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4063:
4064: /*
4065: ** CAPI3REF: Run-Time Limit Categories
4066: ** KEYWORDS: {limit category} {*limit categories}
4067: **
4068: ** These constants define various performance limits
4069: ** that can be lowered at run-time using [sqlite3_limit()].
4070: ** The synopsis of the meanings of the various limits is shown below.
4071: ** Additional information is available at [limits | Limits in SQLite].
4072: **
4073: ** <dl>
4074: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4075: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4076: **
4077: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4078: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4079: **
4080: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4081: ** <dd>The maximum number of columns in a table definition or in the
4082: ** result set of a [SELECT] or the maximum number of columns in an index
4083: ** or in an ORDER BY or GROUP BY clause.</dd>)^
4084: **
4085: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4086: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4087: **
4088: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4089: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4090: **
4091: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4092: ** <dd>The maximum number of instructions in a virtual machine program
4093: ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4094: ** the equivalent tries to allocate space for more than this many opcodes
4095: ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4096: **
4097: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4098: ** <dd>The maximum number of arguments on a function.</dd>)^
4099: **
4100: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4101: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4102: **
4103: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4104: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4105: ** <dd>The maximum length of the pattern argument to the [LIKE] or
4106: ** [GLOB] operators.</dd>)^
4107: **
4108: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4109: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4110: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4111: **
4112: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4113: ** <dd>The maximum depth of recursion for triggers.</dd>)^
4114: **
4115: ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4116: ** <dd>The maximum number of auxiliary worker threads that a single
4117: ** [prepared statement] may start.</dd>)^
4118: ** </dl>
4119: */
4120: #define SQLITE_LIMIT_LENGTH 0
4121: #define SQLITE_LIMIT_SQL_LENGTH 1
4122: #define SQLITE_LIMIT_COLUMN 2
4123: #define SQLITE_LIMIT_EXPR_DEPTH 3
4124: #define SQLITE_LIMIT_COMPOUND_SELECT 4
4125: #define SQLITE_LIMIT_VDBE_OP 5
4126: #define SQLITE_LIMIT_FUNCTION_ARG 6
4127: #define SQLITE_LIMIT_ATTACHED 7
4128: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4129: #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4130: #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4131: #define SQLITE_LIMIT_WORKER_THREADS 11
4132:
4133: /*
4134: ** CAPI3REF: Prepare Flags
4135: **
4136: ** These constants define various flags that can be passed into
4137: ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4138: ** [sqlite3_prepare16_v3()] interfaces.
4139: **
4140: ** New flags may be added in future releases of SQLite.
4141: **
4142: ** <dl>
4143: ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4144: ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4145: ** that the prepared statement will be retained for a long time and
4146: ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4147: ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4148: ** be used just once or at most a few times and then destroyed using
4149: ** [sqlite3_finalize()] relatively soon. The current implementation acts
4150: ** on this hint by avoiding the use of [lookaside memory] so as not to
4151: ** deplete the limited store of lookaside memory. Future versions of
4152: ** SQLite may act on this hint differently.
4153: **
4154: ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4155: ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4156: ** to be required for any prepared statement that wanted to use the
4157: ** [sqlite3_normalized_sql()] interface. However, the
4158: ** [sqlite3_normalized_sql()] interface is now available to all
4159: ** prepared statements, regardless of whether or not they use this
4160: ** flag.
4161: **
4162: ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4163: ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4164: ** to return an error (error code SQLITE_ERROR) if the statement uses
4165: ** any virtual tables.
4166: ** </dl>
4167: */
4168: #define SQLITE_PREPARE_PERSISTENT 0x01
4169: #define SQLITE_PREPARE_NORMALIZE 0x02
4170: #define SQLITE_PREPARE_NO_VTAB 0x04
4171:
4172: /*
4173: ** CAPI3REF: Compiling An SQL Statement
4174: ** KEYWORDS: {SQL statement compiler}
4175: ** METHOD: sqlite3
4176: ** CONSTRUCTOR: sqlite3_stmt
4177: **
4178: ** To execute an SQL statement, it must first be compiled into a byte-code
4179: ** program using one of these routines. Or, in other words, these routines
4180: ** are constructors for the [prepared statement] object.
4181: **
4182: ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4183: ** [sqlite3_prepare()] interface is legacy and should be avoided.
4184: ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4185: ** for special purposes.
4186: **
4187: ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4188: ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4189: ** as a convenience. The UTF-16 interfaces work by converting the
4190: ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4191: **
4192: ** The first argument, "db", is a [database connection] obtained from a
4193: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4194: ** [sqlite3_open16()]. The database connection must not have been closed.
4195: **
4196: ** The second argument, "zSql", is the statement to be compiled, encoded
4197: ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4198: ** and sqlite3_prepare_v3()
4199: ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4200: ** and sqlite3_prepare16_v3() use UTF-16.
4201: **
4202: ** ^If the nByte argument is negative, then zSql is read up to the
4203: ** first zero terminator. ^If nByte is positive, then it is the
4204: ** number of bytes read from zSql. ^If nByte is zero, then no prepared
4205: ** statement is generated.
4206: ** If the caller knows that the supplied string is nul-terminated, then
4207: ** there is a small performance advantage to passing an nByte parameter that
4208: ** is the number of bytes in the input string <i>including</i>
4209: ** the nul-terminator.
4210: **
4211: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4212: ** past the end of the first SQL statement in zSql. These routines only
4213: ** compile the first statement in zSql, so *pzTail is left pointing to
4214: ** what remains uncompiled.
4215: **
4216: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4217: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4218: ** to NULL. ^If the input text contains no SQL (if the input is an empty
4219: ** string or a comment) then *ppStmt is set to NULL.
4220: ** The calling procedure is responsible for deleting the compiled
4221: ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4222: ** ppStmt may not be NULL.
4223: **
4224: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4225: ** otherwise an [error code] is returned.
4226: **
4227: ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4228: ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4229: ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4230: ** are retained for backwards compatibility, but their use is discouraged.
4231: ** ^In the "vX" interfaces, the prepared statement
4232: ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4233: ** original SQL text. This causes the [sqlite3_step()] interface to
4234: ** behave differently in three ways:
4235: **
4236: ** <ol>
4237: ** <li>
4238: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4239: ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4240: ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4241: ** retries will occur before sqlite3_step() gives up and returns an error.
4242: ** </li>
4243: **
4244: ** <li>
4245: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4246: ** [error codes] or [extended error codes]. ^The legacy behavior was that
4247: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4248: ** and the application would have to make a second call to [sqlite3_reset()]
4249: ** in order to find the underlying cause of the problem. With the "v2" prepare
4250: ** interfaces, the underlying reason for the error is returned immediately.
4251: ** </li>
4252: **
4253: ** <li>
4254: ** ^If the specific value bound to a [parameter | host parameter] in the
4255: ** WHERE clause might influence the choice of query plan for a statement,
4256: ** then the statement will be automatically recompiled, as if there had been
4257: ** a schema change, on the first [sqlite3_step()] call following any change
4258: ** to the [sqlite3_bind_text | bindings] of that [parameter].
4259: ** ^The specific value of a WHERE-clause [parameter] might influence the
4260: ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4261: ** or [GLOB] operator or if the parameter is compared to an indexed column
4262: ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4263: ** </li>
4264: ** </ol>
4265: **
4266: ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4267: ** the extra prepFlags parameter, which is a bit array consisting of zero or
4268: ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4269: ** sqlite3_prepare_v2() interface works exactly the same as
4270: ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4271: */
4272: SQLITE_API int sqlite3_prepare(
4273: sqlite3 *db, /* Database handle */
4274: const char *zSql, /* SQL statement, UTF-8 encoded */
4275: int nByte, /* Maximum length of zSql in bytes. */
4276: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4277: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4278: );
4279: SQLITE_API int sqlite3_prepare_v2(
4280: sqlite3 *db, /* Database handle */
4281: const char *zSql, /* SQL statement, UTF-8 encoded */
4282: int nByte, /* Maximum length of zSql in bytes. */
4283: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4284: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4285: );
4286: SQLITE_API int sqlite3_prepare_v3(
4287: sqlite3 *db, /* Database handle */
4288: const char *zSql, /* SQL statement, UTF-8 encoded */
4289: int nByte, /* Maximum length of zSql in bytes. */
4290: unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4291: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4292: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4293: );
4294: SQLITE_API int sqlite3_prepare16(
4295: sqlite3 *db, /* Database handle */
4296: const void *zSql, /* SQL statement, UTF-16 encoded */
4297: int nByte, /* Maximum length of zSql in bytes. */
4298: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4299: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4300: );
4301: SQLITE_API int sqlite3_prepare16_v2(
4302: sqlite3 *db, /* Database handle */
4303: const void *zSql, /* SQL statement, UTF-16 encoded */
4304: int nByte, /* Maximum length of zSql in bytes. */
4305: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4306: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4307: );
4308: SQLITE_API int sqlite3_prepare16_v3(
4309: sqlite3 *db, /* Database handle */
4310: const void *zSql, /* SQL statement, UTF-16 encoded */
4311: int nByte, /* Maximum length of zSql in bytes. */
4312: unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4313: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4314: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4315: );
4316:
4317: /*
4318: ** CAPI3REF: Retrieving Statement SQL
4319: ** METHOD: sqlite3_stmt
4320: **
4321: ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4322: ** SQL text used to create [prepared statement] P if P was
4323: ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4324: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4325: ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4326: ** string containing the SQL text of prepared statement P with
4327: ** [bound parameters] expanded.
4328: ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4329: ** string containing the normalized SQL text of prepared statement P. The
4330: ** semantics used to normalize a SQL statement are unspecified and subject
4331: ** to change. At a minimum, literal values will be replaced with suitable
4332: ** placeholders.
4333: **
4334: ** ^(For example, if a prepared statement is created using the SQL
4335: ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4336: ** and parameter :xyz is unbound, then sqlite3_sql() will return
4337: ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4338: ** will return "SELECT 2345,NULL".)^
4339: **
4340: ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4341: ** is available to hold the result, or if the result would exceed the
4342: ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4343: **
4344: ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4345: ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4346: ** option causes sqlite3_expanded_sql() to always return NULL.
4347: **
4348: ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4349: ** are managed by SQLite and are automatically freed when the prepared
4350: ** statement is finalized.
4351: ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4352: ** is obtained from [sqlite3_malloc()] and must be freed by the application
4353: ** by passing it to [sqlite3_free()].
4354: **
4355: ** ^The sqlite3_normalized_sql() interface is only available if
4356: ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4357: */
4358: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4359: SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4360: #ifdef SQLITE_ENABLE_NORMALIZE
4361: SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4362: #endif
4363:
4364: /*
4365: ** CAPI3REF: Determine If An SQL Statement Writes The Database
4366: ** METHOD: sqlite3_stmt
4367: **
4368: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4369: ** and only if the [prepared statement] X makes no direct changes to
4370: ** the content of the database file.
4371: **
4372: ** Note that [application-defined SQL functions] or
4373: ** [virtual tables] might change the database indirectly as a side effect.
4374: ** ^(For example, if an application defines a function "eval()" that
4375: ** calls [sqlite3_exec()], then the following SQL statement would
4376: ** change the database file through side-effects:
4377: **
4378: ** <blockquote><pre>
4379: ** SELECT eval('DELETE FROM t1') FROM t2;
4380: ** </pre></blockquote>
4381: **
4382: ** But because the [SELECT] statement does not change the database file
4383: ** directly, sqlite3_stmt_readonly() would still return true.)^
4384: **
4385: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4386: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4387: ** since the statements themselves do not actually modify the database but
4388: ** rather they control the timing of when other statements modify the
4389: ** database. ^The [ATTACH] and [DETACH] statements also cause
4390: ** sqlite3_stmt_readonly() to return true since, while those statements
4391: ** change the configuration of a database connection, they do not make
4392: ** changes to the content of the database files on disk.
4393: ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4394: ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4395: ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4396: ** sqlite3_stmt_readonly() returns false for those commands.
4397: **
4398: ** ^This routine returns false if there is any possibility that the
4399: ** statement might change the database file. ^A false return does
4400: ** not guarantee that the statement will change the database file.
4401: ** ^For example, an UPDATE statement might have a WHERE clause that
4402: ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4403: ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4404: ** read-only no-op if the table already exists, but
4405: ** sqlite3_stmt_readonly() still returns false for such a statement.
4406: **
4407: ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4408: ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4409: ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4410: */
4411: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4412:
4413: /*
4414: ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4415: ** METHOD: sqlite3_stmt
4416: **
4417: ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4418: ** prepared statement S is an EXPLAIN statement, or 2 if the
4419: ** statement S is an EXPLAIN QUERY PLAN.
4420: ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4421: ** an ordinary statement or a NULL pointer.
4422: */
4423: SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4424:
4425: /*
4426: ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4427: ** METHOD: sqlite3_stmt
4428: **
4429: ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4430: ** setting for [prepared statement] S. If E is zero, then S becomes
4431: ** a normal prepared statement. If E is 1, then S behaves as if
4432: ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4433: ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4434: **
4435: ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4436: ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4437: ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4438: **
4439: ** Because of the potential need to reprepare, a call to
4440: ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4441: ** reprepared because it was created using [sqlite3_prepare()] instead of
4442: ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4443: ** hence has no saved SQL text with which to reprepare.
4444: **
4445: ** Changing the explain setting for a prepared statement does not change
4446: ** the original SQL text for the statement. Hence, if the SQL text originally
4447: ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4448: ** is called to convert the statement into an ordinary statement, the EXPLAIN
4449: ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4450: ** output, even though the statement now acts like a normal SQL statement.
4451: **
4452: ** This routine returns SQLITE_OK if the explain mode is successfully
4453: ** changed, or an error code if the explain mode could not be changed.
4454: ** The explain mode cannot be changed while a statement is active.
4455: ** Hence, it is good practice to call [sqlite3_reset(S)]
4456: ** immediately prior to calling sqlite3_stmt_explain(S,E).
4457: */
4458: SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4459:
4460: /*
4461: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4462: ** METHOD: sqlite3_stmt
4463: **
4464: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4465: ** [prepared statement] S has been stepped at least once using
4466: ** [sqlite3_step(S)] but has neither run to completion (returned
4467: ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4468: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4469: ** interface returns false if S is a NULL pointer. If S is not a
4470: ** NULL pointer and is not a pointer to a valid [prepared statement]
4471: ** object, then the behavior is undefined and probably undesirable.
4472: **
4473: ** This interface can be used in combination [sqlite3_next_stmt()]
4474: ** to locate all prepared statements associated with a database
4475: ** connection that are in need of being reset. This can be used,
4476: ** for example, in diagnostic routines to search for prepared
4477: ** statements that are holding a transaction open.
4478: */
4479: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4480:
4481: /*
4482: ** CAPI3REF: Dynamically Typed Value Object
4483: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4484: **
4485: ** SQLite uses the sqlite3_value object to represent all values
4486: ** that can be stored in a database table. SQLite uses dynamic typing
4487: ** for the values it stores. ^Values stored in sqlite3_value objects
4488: ** can be integers, floating point values, strings, BLOBs, or NULL.
4489: **
4490: ** An sqlite3_value object may be either "protected" or "unprotected".
4491: ** Some interfaces require a protected sqlite3_value. Other interfaces
4492: ** will accept either a protected or an unprotected sqlite3_value.
4493: ** Every interface that accepts sqlite3_value arguments specifies
4494: ** whether or not it requires a protected sqlite3_value. The
4495: ** [sqlite3_value_dup()] interface can be used to construct a new
4496: ** protected sqlite3_value from an unprotected sqlite3_value.
4497: **
4498: ** The terms "protected" and "unprotected" refer to whether or not
4499: ** a mutex is held. An internal mutex is held for a protected
4500: ** sqlite3_value object but no mutex is held for an unprotected
4501: ** sqlite3_value object. If SQLite is compiled to be single-threaded
4502: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4503: ** or if SQLite is run in one of reduced mutex modes
4504: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4505: ** then there is no distinction between protected and unprotected
4506: ** sqlite3_value objects and they can be used interchangeably. However,
4507: ** for maximum code portability it is recommended that applications
4508: ** still make the distinction between protected and unprotected
4509: ** sqlite3_value objects even when not strictly required.
4510: **
4511: ** ^The sqlite3_value objects that are passed as parameters into the
4512: ** implementation of [application-defined SQL functions] are protected.
4513: ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4514: ** are protected.
4515: ** ^The sqlite3_value object returned by
4516: ** [sqlite3_column_value()] is unprotected.
4517: ** Unprotected sqlite3_value objects may only be used as arguments
4518: ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4519: ** [sqlite3_value_dup()].
4520: ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4521: ** interfaces require protected sqlite3_value objects.
4522: */
4523: typedef struct sqlite3_value sqlite3_value;
4524:
4525: /*
4526: ** CAPI3REF: SQL Function Context Object
4527: **
4528: ** The context in which an SQL function executes is stored in an
4529: ** sqlite3_context object. ^A pointer to an sqlite3_context object
4530: ** is always first parameter to [application-defined SQL functions].
4531: ** The application-defined SQL function implementation will pass this
4532: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4533: ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4534: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4535: ** and/or [sqlite3_set_auxdata()].
4536: */
4537: typedef struct sqlite3_context sqlite3_context;
4538:
4539: /*
4540: ** CAPI3REF: Binding Values To Prepared Statements
4541: ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4542: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4543: ** METHOD: sqlite3_stmt
4544: **
4545: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4546: ** literals may be replaced by a [parameter] that matches one of following
4547: ** templates:
4548: **
4549: ** <ul>
4550: ** <li> ?
4551: ** <li> ?NNN
4552: ** <li> :VVV
4553: ** <li> @VVV
4554: ** <li> $VVV
4555: ** </ul>
4556: **
4557: ** In the templates above, NNN represents an integer literal,
4558: ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4559: ** parameters (also called "host parameter names" or "SQL parameters")
4560: ** can be set using the sqlite3_bind_*() routines defined here.
4561: **
4562: ** ^The first argument to the sqlite3_bind_*() routines is always
4563: ** a pointer to the [sqlite3_stmt] object returned from
4564: ** [sqlite3_prepare_v2()] or its variants.
4565: **
4566: ** ^The second argument is the index of the SQL parameter to be set.
4567: ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4568: ** SQL parameter is used more than once, second and subsequent
4569: ** occurrences have the same index as the first occurrence.
4570: ** ^The index for named parameters can be looked up using the
4571: ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4572: ** for "?NNN" parameters is the value of NNN.
4573: ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4574: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4575: **
4576: ** ^The third argument is the value to bind to the parameter.
4577: ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4578: ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4579: ** is ignored and the end result is the same as sqlite3_bind_null().
4580: ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4581: ** it should be a pointer to well-formed UTF8 text.
4582: ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4583: ** it should be a pointer to well-formed UTF16 text.
4584: ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4585: ** it should be a pointer to a well-formed unicode string that is
4586: ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4587: ** otherwise.
4588: **
4589: ** [[byte-order determination rules]] ^The byte-order of
4590: ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4591: ** found in first character, which is removed, or in the absence of a BOM
4592: ** the byte order is the native byte order of the host
4593: ** machine for sqlite3_bind_text16() or the byte order specified in
4594: ** the 6th parameter for sqlite3_bind_text64().)^
4595: ** ^If UTF16 input text contains invalid unicode
4596: ** characters, then SQLite might change those invalid characters
4597: ** into the unicode replacement character: U+FFFD.
4598: **
4599: ** ^(In those routines that have a fourth argument, its value is the
4600: ** number of bytes in the parameter. To be clear: the value is the
4601: ** number of <u>bytes</u> in the value, not the number of characters.)^
4602: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4603: ** is negative, then the length of the string is
4604: ** the number of bytes up to the first zero terminator.
4605: ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4606: ** the behavior is undefined.
4607: ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4608: ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4609: ** that parameter must be the byte offset
4610: ** where the NUL terminator would occur assuming the string were NUL
4611: ** terminated. If any NUL characters occurs at byte offsets less than
4612: ** the value of the fourth parameter then the resulting string value will
4613: ** contain embedded NULs. The result of expressions involving strings
4614: ** with embedded NULs is undefined.
4615: **
4616: ** ^The fifth argument to the BLOB and string binding interfaces controls
4617: ** or indicates the lifetime of the object referenced by the third parameter.
4618: ** These three options exist:
4619: ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4620: ** with it may be passed. ^It is called to dispose of the BLOB or string even
4621: ** if the call to the bind API fails, except the destructor is not called if
4622: ** the third parameter is a NULL pointer or the fourth parameter is negative.
4623: ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4624: ** the application remains responsible for disposing of the object. ^In this
4625: ** case, the object and the provided pointer to it must remain valid until
4626: ** either the prepared statement is finalized or the same SQL parameter is
4627: ** bound to something else, whichever occurs sooner.
4628: ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4629: ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4630: ** object and pointer to it must remain valid until then. ^SQLite will then
4631: ** manage the lifetime of its private copy.
4632: **
4633: ** ^The sixth argument to sqlite3_bind_text64() must be one of
4634: ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4635: ** to specify the encoding of the text in the third parameter. If
4636: ** the sixth argument to sqlite3_bind_text64() is not one of the
4637: ** allowed values shown above, or if the text encoding is different
4638: ** from the encoding specified by the sixth parameter, then the behavior
4639: ** is undefined.
4640: **
4641: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4642: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4643: ** (just an integer to hold its size) while it is being processed.
4644: ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4645: ** content is later written using
4646: ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4647: ** ^A negative value for the zeroblob results in a zero-length BLOB.
4648: **
4649: ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4650: ** [prepared statement] S to have an SQL value of NULL, but to also be
4651: ** associated with the pointer P of type T. ^D is either a NULL pointer or
4652: ** a pointer to a destructor function for P. ^SQLite will invoke the
4653: ** destructor D with a single argument of P when it is finished using
4654: ** P. The T parameter should be a static string, preferably a string
4655: ** literal. The sqlite3_bind_pointer() routine is part of the
4656: ** [pointer passing interface] added for SQLite 3.20.0.
4657: **
4658: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4659: ** for the [prepared statement] or with a prepared statement for which
4660: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4661: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4662: ** routine is passed a [prepared statement] that has been finalized, the
4663: ** result is undefined and probably harmful.
4664: **
4665: ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4666: ** ^Unbound parameters are interpreted as NULL.
4667: **
4668: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4669: ** [error code] if anything goes wrong.
4670: ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4671: ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4672: ** [SQLITE_MAX_LENGTH].
4673: ** ^[SQLITE_RANGE] is returned if the parameter
4674: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4675: **
4676: ** See also: [sqlite3_bind_parameter_count()],
4677: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4678: */
4679: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4680: SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4681: void(*)(void*));
4682: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4683: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4684: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4685: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4686: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4687: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4688: SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4689: void(*)(void*), unsigned char encoding);
4690: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4691: SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4692: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4693: SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4694:
4695: /*
4696: ** CAPI3REF: Number Of SQL Parameters
4697: ** METHOD: sqlite3_stmt
4698: **
4699: ** ^This routine can be used to find the number of [SQL parameters]
4700: ** in a [prepared statement]. SQL parameters are tokens of the
4701: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4702: ** placeholders for values that are [sqlite3_bind_blob | bound]
4703: ** to the parameters at a later time.
4704: **
4705: ** ^(This routine actually returns the index of the largest (rightmost)
4706: ** parameter. For all forms except ?NNN, this will correspond to the
4707: ** number of unique parameters. If parameters of the ?NNN form are used,
4708: ** there may be gaps in the list.)^
4709: **
4710: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4711: ** [sqlite3_bind_parameter_name()], and
4712: ** [sqlite3_bind_parameter_index()].
4713: */
4714: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4715:
4716: /*
4717: ** CAPI3REF: Name Of A Host Parameter
4718: ** METHOD: sqlite3_stmt
4719: **
4720: ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4721: ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4722: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4723: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4724: ** respectively.
4725: ** In other words, the initial ":" or "$" or "@" or "?"
4726: ** is included as part of the name.)^
4727: ** ^Parameters of the form "?" without a following integer have no name
4728: ** and are referred to as "nameless" or "anonymous parameters".
4729: **
4730: ** ^The first host parameter has an index of 1, not 0.
4731: **
4732: ** ^If the value N is out of range or if the N-th parameter is
4733: ** nameless, then NULL is returned. ^The returned string is
4734: ** always in UTF-8 encoding even if the named parameter was
4735: ** originally specified as UTF-16 in [sqlite3_prepare16()],
4736: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4737: **
4738: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4739: ** [sqlite3_bind_parameter_count()], and
4740: ** [sqlite3_bind_parameter_index()].
4741: */
4742: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4743:
4744: /*
4745: ** CAPI3REF: Index Of A Parameter With A Given Name
4746: ** METHOD: sqlite3_stmt
4747: **
4748: ** ^Return the index of an SQL parameter given its name. ^The
4749: ** index value returned is suitable for use as the second
4750: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4751: ** is returned if no matching parameter is found. ^The parameter
4752: ** name must be given in UTF-8 even if the original statement
4753: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4754: ** [sqlite3_prepare16_v3()].
4755: **
4756: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4757: ** [sqlite3_bind_parameter_count()], and
4758: ** [sqlite3_bind_parameter_name()].
4759: */
4760: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4761:
4762: /*
4763: ** CAPI3REF: Reset All Bindings On A Prepared Statement
4764: ** METHOD: sqlite3_stmt
4765: **
4766: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4767: ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4768: ** ^Use this routine to reset all host parameters to NULL.
4769: */
4770: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4771:
4772: /*
4773: ** CAPI3REF: Number Of Columns In A Result Set
4774: ** METHOD: sqlite3_stmt
4775: **
4776: ** ^Return the number of columns in the result set returned by the
4777: ** [prepared statement]. ^If this routine returns 0, that means the
4778: ** [prepared statement] returns no data (for example an [UPDATE]).
4779: ** ^However, just because this routine returns a positive number does not
4780: ** mean that one or more rows of data will be returned. ^A SELECT statement
4781: ** will always have a positive sqlite3_column_count() but depending on the
4782: ** WHERE clause constraints and the table content, it might return no rows.
4783: **
4784: ** See also: [sqlite3_data_count()]
4785: */
4786: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4787:
4788: /*
4789: ** CAPI3REF: Column Names In A Result Set
4790: ** METHOD: sqlite3_stmt
4791: **
4792: ** ^These routines return the name assigned to a particular column
4793: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4794: ** interface returns a pointer to a zero-terminated UTF-8 string
4795: ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4796: ** UTF-16 string. ^The first parameter is the [prepared statement]
4797: ** that implements the [SELECT] statement. ^The second parameter is the
4798: ** column number. ^The leftmost column is number 0.
4799: **
4800: ** ^The returned string pointer is valid until either the [prepared statement]
4801: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4802: ** reprepared by the first call to [sqlite3_step()] for a particular run
4803: ** or until the next call to
4804: ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4805: **
4806: ** ^If sqlite3_malloc() fails during the processing of either routine
4807: ** (for example during a conversion from UTF-8 to UTF-16) then a
4808: ** NULL pointer is returned.
4809: **
4810: ** ^The name of a result column is the value of the "AS" clause for
4811: ** that column, if there is an AS clause. If there is no AS clause
4812: ** then the name of the column is unspecified and may change from
4813: ** one release of SQLite to the next.
4814: */
4815: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4816: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4817:
4818: /*
4819: ** CAPI3REF: Source Of Data In A Query Result
4820: ** METHOD: sqlite3_stmt
4821: **
4822: ** ^These routines provide a means to determine the database, table, and
4823: ** table column that is the origin of a particular result column in
4824: ** [SELECT] statement.
4825: ** ^The name of the database or table or column can be returned as
4826: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4827: ** the database name, the _table_ routines return the table name, and
4828: ** the origin_ routines return the column name.
4829: ** ^The returned string is valid until the [prepared statement] is destroyed
4830: ** using [sqlite3_finalize()] or until the statement is automatically
4831: ** reprepared by the first call to [sqlite3_step()] for a particular run
4832: ** or until the same information is requested
4833: ** again in a different encoding.
4834: **
4835: ** ^The names returned are the original un-aliased names of the
4836: ** database, table, and column.
4837: **
4838: ** ^The first argument to these interfaces is a [prepared statement].
4839: ** ^These functions return information about the Nth result column returned by
4840: ** the statement, where N is the second function argument.
4841: ** ^The left-most column is column 0 for these routines.
4842: **
4843: ** ^If the Nth column returned by the statement is an expression or
4844: ** subquery and is not a column value, then all of these functions return
4845: ** NULL. ^These routines might also return NULL if a memory allocation error
4846: ** occurs. ^Otherwise, they return the name of the attached database, table,
4847: ** or column that query result column was extracted from.
4848: **
4849: ** ^As with all other SQLite APIs, those whose names end with "16" return
4850: ** UTF-16 encoded strings and the other functions return UTF-8.
4851: **
4852: ** ^These APIs are only available if the library was compiled with the
4853: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4854: **
4855: ** If two or more threads call one or more
4856: ** [sqlite3_column_database_name | column metadata interfaces]
4857: ** for the same [prepared statement] and result column
4858: ** at the same time then the results are undefined.
4859: */
4860: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4861: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4862: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4863: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4864: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4865: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4866:
4867: /*
4868: ** CAPI3REF: Declared Datatype Of A Query Result
4869: ** METHOD: sqlite3_stmt
4870: **
4871: ** ^(The first parameter is a [prepared statement].
4872: ** If this statement is a [SELECT] statement and the Nth column of the
4873: ** returned result set of that [SELECT] is a table column (not an
4874: ** expression or subquery) then the declared type of the table
4875: ** column is returned.)^ ^If the Nth column of the result set is an
4876: ** expression or subquery, then a NULL pointer is returned.
4877: ** ^The returned string is always UTF-8 encoded.
4878: **
4879: ** ^(For example, given the database schema:
4880: **
4881: ** CREATE TABLE t1(c1 VARIANT);
4882: **
4883: ** and the following statement to be compiled:
4884: **
4885: ** SELECT c1 + 1, c1 FROM t1;
4886: **
4887: ** this routine would return the string "VARIANT" for the second result
4888: ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4889: **
4890: ** ^SQLite uses dynamic run-time typing. ^So just because a column
4891: ** is declared to contain a particular type does not mean that the
4892: ** data stored in that column is of the declared type. SQLite is
4893: ** strongly typed, but the typing is dynamic not static. ^Type
4894: ** is associated with individual values, not with the containers
4895: ** used to hold those values.
4896: */
4897: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4898: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4899:
4900: /*
4901: ** CAPI3REF: Evaluate An SQL Statement
4902: ** METHOD: sqlite3_stmt
4903: **
4904: ** After a [prepared statement] has been prepared using any of
4905: ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4906: ** or [sqlite3_prepare16_v3()] or one of the legacy
4907: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4908: ** must be called one or more times to evaluate the statement.
4909: **
4910: ** The details of the behavior of the sqlite3_step() interface depend
4911: ** on whether the statement was prepared using the newer "vX" interfaces
4912: ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4913: ** [sqlite3_prepare16_v2()] or the older legacy
4914: ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4915: ** new "vX" interface is recommended for new applications but the legacy
4916: ** interface will continue to be supported.
4917: **
4918: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4919: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4920: ** ^With the "v2" interface, any of the other [result codes] or
4921: ** [extended result codes] might be returned as well.
4922: **
4923: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4924: ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4925: ** or occurs outside of an explicit transaction, then you can retry the
4926: ** statement. If the statement is not a [COMMIT] and occurs within an
4927: ** explicit transaction then you should rollback the transaction before
4928: ** continuing.
4929: **
4930: ** ^[SQLITE_DONE] means that the statement has finished executing
4931: ** successfully. sqlite3_step() should not be called again on this virtual
4932: ** machine without first calling [sqlite3_reset()] to reset the virtual
4933: ** machine back to its initial state.
4934: **
4935: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4936: ** is returned each time a new row of data is ready for processing by the
4937: ** caller. The values may be accessed using the [column access functions].
4938: ** sqlite3_step() is called again to retrieve the next row of data.
4939: **
4940: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4941: ** violation) has occurred. sqlite3_step() should not be called again on
4942: ** the VM. More information may be found by calling [sqlite3_errmsg()].
4943: ** ^With the legacy interface, a more specific error code (for example,
4944: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4945: ** can be obtained by calling [sqlite3_reset()] on the
4946: ** [prepared statement]. ^In the "v2" interface,
4947: ** the more specific error code is returned directly by sqlite3_step().
4948: **
4949: ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4950: ** Perhaps it was called on a [prepared statement] that has
4951: ** already been [sqlite3_finalize | finalized] or on one that had
4952: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4953: ** be the case that the same database connection is being used by two or
4954: ** more threads at the same moment in time.
4955: **
4956: ** For all versions of SQLite up to and including 3.6.23.1, a call to
4957: ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4958: ** other than [SQLITE_ROW] before any subsequent invocation of
4959: ** sqlite3_step(). Failure to reset the prepared statement using
4960: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4961: ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4962: ** sqlite3_step() began
4963: ** calling [sqlite3_reset()] automatically in this circumstance rather
4964: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4965: ** break because any application that ever receives an SQLITE_MISUSE error
4966: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4967: ** can be used to restore the legacy behavior.
4968: **
4969: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4970: ** API always returns a generic error code, [SQLITE_ERROR], following any
4971: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4972: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4973: ** specific [error codes] that better describes the error.
4974: ** We admit that this is a goofy design. The problem has been fixed
4975: ** with the "v2" interface. If you prepare all of your SQL statements
4976: ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4977: ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4978: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4979: ** then the more specific [error codes] are returned directly
4980: ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4981: */
4982: SQLITE_API int sqlite3_step(sqlite3_stmt*);
4983:
4984: /*
4985: ** CAPI3REF: Number of columns in a result set
4986: ** METHOD: sqlite3_stmt
4987: **
4988: ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4989: ** current row of the result set of [prepared statement] P.
4990: ** ^If prepared statement P does not have results ready to return
4991: ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4992: ** interfaces) then sqlite3_data_count(P) returns 0.
4993: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4994: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4995: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4996: ** will return non-zero if previous call to [sqlite3_step](P) returned
4997: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4998: ** where it always returns zero since each step of that multi-step
4999: ** pragma returns 0 columns of data.
5000: **
5001: ** See also: [sqlite3_column_count()]
5002: */
5003: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5004:
5005: /*
5006: ** CAPI3REF: Fundamental Datatypes
5007: ** KEYWORDS: SQLITE_TEXT
5008: **
5009: ** ^(Every value in SQLite has one of five fundamental datatypes:
5010: **
5011: ** <ul>
5012: ** <li> 64-bit signed integer
5013: ** <li> 64-bit IEEE floating point number
5014: ** <li> string
5015: ** <li> BLOB
5016: ** <li> NULL
5017: ** </ul>)^
5018: **
5019: ** These constants are codes for each of those types.
5020: **
5021: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5022: ** for a completely different meaning. Software that links against both
5023: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5024: ** SQLITE_TEXT.
5025: */
5026: #define SQLITE_INTEGER 1
5027: #define SQLITE_FLOAT 2
5028: #define SQLITE_BLOB 4
5029: #define SQLITE_NULL 5
5030: #ifdef SQLITE_TEXT
5031: # undef SQLITE_TEXT
5032: #else
5033: # define SQLITE_TEXT 3
5034: #endif
5035: #define SQLITE3_TEXT 3
5036:
5037: /*
5038: ** CAPI3REF: Result Values From A Query
5039: ** KEYWORDS: {column access functions}
5040: ** METHOD: sqlite3_stmt
5041: **
5042: ** <b>Summary:</b>
5043: ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5044: ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
5045: ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
5046: ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
5047: ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
5048: ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
5049: ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
5050: ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
5051: ** [sqlite3_value|unprotected sqlite3_value] object.
5052: ** <tr><td> <td> <td>
5053: ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
5054: ** or a UTF-8 TEXT result in bytes
5055: ** <tr><td><b>sqlite3_column_bytes16 </b>
5056: ** <td>→ <td>Size of UTF-16
5057: ** TEXT in bytes
5058: ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
5059: ** datatype of the result
5060: ** </table></blockquote>
5061: **
5062: ** <b>Details:</b>
5063: **
5064: ** ^These routines return information about a single column of the current
5065: ** result row of a query. ^In every case the first argument is a pointer
5066: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5067: ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5068: ** and the second argument is the index of the column for which information
5069: ** should be returned. ^The leftmost column of the result set has the index 0.
5070: ** ^The number of columns in the result can be determined using
5071: ** [sqlite3_column_count()].
5072: **
5073: ** If the SQL statement does not currently point to a valid row, or if the
5074: ** column index is out of range, the result is undefined.
5075: ** These routines may only be called when the most recent call to
5076: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5077: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5078: ** If any of these routines are called after [sqlite3_reset()] or
5079: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5080: ** something other than [SQLITE_ROW], the results are undefined.
5081: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5082: ** are called from a different thread while any of these routines
5083: ** are pending, then the results are undefined.
5084: **
5085: ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5086: ** each return the value of a result column in a specific data format. If
5087: ** the result column is not initially in the requested format (for example,
5088: ** if the query returns an integer but the sqlite3_column_text() interface
5089: ** is used to extract the value) then an automatic type conversion is performed.
5090: **
5091: ** ^The sqlite3_column_type() routine returns the
5092: ** [SQLITE_INTEGER | datatype code] for the initial data type
5093: ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5094: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5095: ** The return value of sqlite3_column_type() can be used to decide which
5096: ** of the first six interface should be used to extract the column value.
5097: ** The value returned by sqlite3_column_type() is only meaningful if no
5098: ** automatic type conversions have occurred for the value in question.
5099: ** After a type conversion, the result of calling sqlite3_column_type()
5100: ** is undefined, though harmless. Future
5101: ** versions of SQLite may change the behavior of sqlite3_column_type()
5102: ** following a type conversion.
5103: **
5104: ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5105: ** or sqlite3_column_bytes16() interfaces can be used to determine the size
5106: ** of that BLOB or string.
5107: **
5108: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5109: ** routine returns the number of bytes in that BLOB or string.
5110: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5111: ** the string to UTF-8 and then returns the number of bytes.
5112: ** ^If the result is a numeric value then sqlite3_column_bytes() uses
5113: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5114: ** the number of bytes in that string.
5115: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5116: **
5117: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5118: ** routine returns the number of bytes in that BLOB or string.
5119: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5120: ** the string to UTF-16 and then returns the number of bytes.
5121: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5122: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5123: ** the number of bytes in that string.
5124: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5125: **
5126: ** ^The values returned by [sqlite3_column_bytes()] and
5127: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5128: ** of the string. ^For clarity: the values returned by
5129: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5130: ** bytes in the string, not the number of characters.
5131: **
5132: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5133: ** even empty strings, are always zero-terminated. ^The return
5134: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5135: **
5136: ** ^Strings returned by sqlite3_column_text16() always have the endianness
5137: ** which is native to the platform, regardless of the text encoding set
5138: ** for the database.
5139: **
5140: ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5141: ** [unprotected sqlite3_value] object. In a multithreaded environment,
5142: ** an unprotected sqlite3_value object may only be used safely with
5143: ** [sqlite3_bind_value()] and [sqlite3_result_value()].
5144: ** If the [unprotected sqlite3_value] object returned by
5145: ** [sqlite3_column_value()] is used in any other way, including calls
5146: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5147: ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5148: ** Hence, the sqlite3_column_value() interface
5149: ** is normally only useful within the implementation of
5150: ** [application-defined SQL functions] or [virtual tables], not within
5151: ** top-level application code.
5152: **
5153: ** These routines may attempt to convert the datatype of the result.
5154: ** ^For example, if the internal representation is FLOAT and a text result
5155: ** is requested, [sqlite3_snprintf()] is used internally to perform the
5156: ** conversion automatically. ^(The following table details the conversions
5157: ** that are applied:
5158: **
5159: ** <blockquote>
5160: ** <table border="1">
5161: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5162: **
5163: ** <tr><td> NULL <td> INTEGER <td> Result is 0
5164: ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5165: ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5166: ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5167: ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5168: ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5169: ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5170: ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5171: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5172: ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5173: ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5174: ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5175: ** <tr><td> TEXT <td> BLOB <td> No change
5176: ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5177: ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5178: ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5179: ** </table>
5180: ** </blockquote>)^
5181: **
5182: ** Note that when type conversions occur, pointers returned by prior
5183: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5184: ** sqlite3_column_text16() may be invalidated.
5185: ** Type conversions and pointer invalidations might occur
5186: ** in the following cases:
5187: **
5188: ** <ul>
5189: ** <li> The initial content is a BLOB and sqlite3_column_text() or
5190: ** sqlite3_column_text16() is called. A zero-terminator might
5191: ** need to be added to the string.</li>
5192: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5193: ** sqlite3_column_text16() is called. The content must be converted
5194: ** to UTF-16.</li>
5195: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5196: ** sqlite3_column_text() is called. The content must be converted
5197: ** to UTF-8.</li>
5198: ** </ul>
5199: **
5200: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5201: ** not invalidate a prior pointer, though of course the content of the buffer
5202: ** that the prior pointer references will have been modified. Other kinds
5203: ** of conversion are done in place when it is possible, but sometimes they
5204: ** are not possible and in those cases prior pointers are invalidated.
5205: **
5206: ** The safest policy is to invoke these routines
5207: ** in one of the following ways:
5208: **
5209: ** <ul>
5210: ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5211: ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5212: ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5213: ** </ul>
5214: **
5215: ** In other words, you should call sqlite3_column_text(),
5216: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5217: ** into the desired format, then invoke sqlite3_column_bytes() or
5218: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5219: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5220: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5221: ** with calls to sqlite3_column_bytes().
5222: **
5223: ** ^The pointers returned are valid until a type conversion occurs as
5224: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5225: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5226: ** and BLOBs is freed automatically. Do not pass the pointers returned
5227: ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5228: ** [sqlite3_free()].
5229: **
5230: ** As long as the input parameters are correct, these routines will only
5231: ** fail if an out-of-memory error occurs during a format conversion.
5232: ** Only the following subset of interfaces are subject to out-of-memory
5233: ** errors:
5234: **
5235: ** <ul>
5236: ** <li> sqlite3_column_blob()
5237: ** <li> sqlite3_column_text()
5238: ** <li> sqlite3_column_text16()
5239: ** <li> sqlite3_column_bytes()
5240: ** <li> sqlite3_column_bytes16()
5241: ** </ul>
5242: **
5243: ** If an out-of-memory error occurs, then the return value from these
5244: ** routines is the same as if the column had contained an SQL NULL value.
5245: ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5246: ** by invoking the [sqlite3_errcode()] immediately after the suspect
5247: ** return value is obtained and before any
5248: ** other SQLite interface is called on the same [database connection].
5249: */
5250: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5251: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5252: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5253: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5254: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5255: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5256: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5257: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5258: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5259: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5260:
5261: /*
5262: ** CAPI3REF: Destroy A Prepared Statement Object
5263: ** DESTRUCTOR: sqlite3_stmt
5264: **
5265: ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5266: ** ^If the most recent evaluation of the statement encountered no errors
5267: ** or if the statement is never been evaluated, then sqlite3_finalize() returns
5268: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5269: ** sqlite3_finalize(S) returns the appropriate [error code] or
5270: ** [extended error code].
5271: **
5272: ** ^The sqlite3_finalize(S) routine can be called at any point during
5273: ** the life cycle of [prepared statement] S:
5274: ** before statement S is ever evaluated, after
5275: ** one or more calls to [sqlite3_reset()], or after any call
5276: ** to [sqlite3_step()] regardless of whether or not the statement has
5277: ** completed execution.
5278: **
5279: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5280: **
5281: ** The application must finalize every [prepared statement] in order to avoid
5282: ** resource leaks. It is a grievous error for the application to try to use
5283: ** a prepared statement after it has been finalized. Any use of a prepared
5284: ** statement after it has been finalized can result in undefined and
5285: ** undesirable behavior such as segfaults and heap corruption.
5286: */
5287: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5288:
5289: /*
5290: ** CAPI3REF: Reset A Prepared Statement Object
5291: ** METHOD: sqlite3_stmt
5292: **
5293: ** The sqlite3_reset() function is called to reset a [prepared statement]
5294: ** object back to its initial state, ready to be re-executed.
5295: ** ^Any SQL statement variables that had values bound to them using
5296: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5297: ** Use [sqlite3_clear_bindings()] to reset the bindings.
5298: **
5299: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5300: ** back to the beginning of its program.
5301: **
5302: ** ^The return code from [sqlite3_reset(S)] indicates whether or not
5303: ** the previous evaluation of prepared statement S completed successfully.
5304: ** ^If [sqlite3_step(S)] has never before been called on S or if
5305: ** [sqlite3_step(S)] has not been called since the previous call
5306: ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5307: ** [SQLITE_OK].
5308: **
5309: ** ^If the most recent call to [sqlite3_step(S)] for the
5310: ** [prepared statement] S indicated an error, then
5311: ** [sqlite3_reset(S)] returns an appropriate [error code].
5312: ** ^The [sqlite3_reset(S)] interface might also return an [error code]
5313: ** if there were no prior errors but the process of resetting
5314: ** the prepared statement caused a new error. ^For example, if an
5315: ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5316: ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5317: ** the overall statement might still fail and the [sqlite3_reset(S)] call
5318: ** might return SQLITE_BUSY if locking constraints prevent the
5319: ** database change from committing. Therefore, it is important that
5320: ** applications check the return code from [sqlite3_reset(S)] even if
5321: ** no prior call to [sqlite3_step(S)] indicated a problem.
5322: **
5323: ** ^The [sqlite3_reset(S)] interface does not change the values
5324: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5325: */
5326: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5327:
5328: /*
5329: ** CAPI3REF: Create Or Redefine SQL Functions
5330: ** KEYWORDS: {function creation routines}
5331: ** METHOD: sqlite3
5332: **
5333: ** ^These functions (collectively known as "function creation routines")
5334: ** are used to add SQL functions or aggregates or to redefine the behavior
5335: ** of existing SQL functions or aggregates. The only differences between
5336: ** the three "sqlite3_create_function*" routines are the text encoding
5337: ** expected for the second parameter (the name of the function being
5338: ** created) and the presence or absence of a destructor callback for
5339: ** the application data pointer. Function sqlite3_create_window_function()
5340: ** is similar, but allows the user to supply the extra callback functions
5341: ** needed by [aggregate window functions].
5342: **
5343: ** ^The first parameter is the [database connection] to which the SQL
5344: ** function is to be added. ^If an application uses more than one database
5345: ** connection then application-defined SQL functions must be added
5346: ** to each database connection separately.
5347: **
5348: ** ^The second parameter is the name of the SQL function to be created or
5349: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5350: ** representation, exclusive of the zero-terminator. ^Note that the name
5351: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5352: ** ^Any attempt to create a function with a longer name
5353: ** will result in [SQLITE_MISUSE] being returned.
5354: **
5355: ** ^The third parameter (nArg)
5356: ** is the number of arguments that the SQL function or
5357: ** aggregate takes. ^If this parameter is -1, then the SQL function or
5358: ** aggregate may take any number of arguments between 0 and the limit
5359: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5360: ** parameter is less than -1 or greater than 127 then the behavior is
5361: ** undefined.
5362: **
5363: ** ^The fourth parameter, eTextRep, specifies what
5364: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5365: ** its parameters. The application should set this parameter to
5366: ** [SQLITE_UTF16LE] if the function implementation invokes
5367: ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5368: ** implementation invokes [sqlite3_value_text16be()] on an input, or
5369: ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5370: ** otherwise. ^The same SQL function may be registered multiple times using
5371: ** different preferred text encodings, with different implementations for
5372: ** each encoding.
5373: ** ^When multiple implementations of the same function are available, SQLite
5374: ** will pick the one that involves the least amount of data conversion.
5375: **
5376: ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5377: ** to signal that the function will always return the same result given
5378: ** the same inputs within a single SQL statement. Most SQL functions are
5379: ** deterministic. The built-in [random()] SQL function is an example of a
5380: ** function that is not deterministic. The SQLite query planner is able to
5381: ** perform additional optimizations on deterministic functions, so use
5382: ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5383: **
5384: ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5385: ** flag, which if present prevents the function from being invoked from
5386: ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5387: ** index expressions, or the WHERE clause of partial indexes.
5388: **
5389: ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5390: ** all application-defined SQL functions that do not need to be
5391: ** used inside of triggers, view, CHECK constraints, or other elements of
5392: ** the database schema. This flags is especially recommended for SQL
5393: ** functions that have side effects or reveal internal application state.
5394: ** Without this flag, an attacker might be able to modify the schema of
5395: ** a database file to include invocations of the function with parameters
5396: ** chosen by the attacker, which the application will then execute when
5397: ** the database file is opened and read.
5398: **
5399: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5400: ** function can gain access to this pointer using [sqlite3_user_data()].)^
5401: **
5402: ** ^The sixth, seventh and eighth parameters passed to the three
5403: ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5404: ** pointers to C-language functions that implement the SQL function or
5405: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5406: ** callback only; NULL pointers must be passed as the xStep and xFinal
5407: ** parameters. ^An aggregate SQL function requires an implementation of xStep
5408: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5409: ** SQL function or aggregate, pass NULL pointers for all three function
5410: ** callbacks.
5411: **
5412: ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5413: ** and xInverse) passed to sqlite3_create_window_function are pointers to
5414: ** C-language callbacks that implement the new function. xStep and xFinal
5415: ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5416: ** which case a regular aggregate function is created, or must both be
5417: ** non-NULL, in which case the new function may be used as either an aggregate
5418: ** or aggregate window function. More details regarding the implementation
5419: ** of aggregate window functions are
5420: ** [user-defined window functions|available here].
5421: **
5422: ** ^(If the final parameter to sqlite3_create_function_v2() or
5423: ** sqlite3_create_window_function() is not NULL, then it is destructor for
5424: ** the application data pointer. The destructor is invoked when the function
5425: ** is deleted, either by being overloaded or when the database connection
5426: ** closes.)^ ^The destructor is also invoked if the call to
5427: ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5428: ** invoked, it is passed a single argument which is a copy of the application
5429: ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5430: **
5431: ** ^It is permitted to register multiple implementations of the same
5432: ** functions with the same name but with either differing numbers of
5433: ** arguments or differing preferred text encodings. ^SQLite will use
5434: ** the implementation that most closely matches the way in which the
5435: ** SQL function is used. ^A function implementation with a non-negative
5436: ** nArg parameter is a better match than a function implementation with
5437: ** a negative nArg. ^A function where the preferred text encoding
5438: ** matches the database encoding is a better
5439: ** match than a function where the encoding is different.
5440: ** ^A function where the encoding difference is between UTF16le and UTF16be
5441: ** is a closer match than a function where the encoding difference is
5442: ** between UTF8 and UTF16.
5443: **
5444: ** ^Built-in functions may be overloaded by new application-defined functions.
5445: **
5446: ** ^An application-defined function is permitted to call other
5447: ** SQLite interfaces. However, such calls must not
5448: ** close the database connection nor finalize or reset the prepared
5449: ** statement in which the function is running.
5450: */
5451: SQLITE_API int sqlite3_create_function(
5452: sqlite3 *db,
5453: const char *zFunctionName,
5454: int nArg,
5455: int eTextRep,
5456: void *pApp,
5457: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5458: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5459: void (*xFinal)(sqlite3_context*)
5460: );
5461: SQLITE_API int sqlite3_create_function16(
5462: sqlite3 *db,
5463: const void *zFunctionName,
5464: int nArg,
5465: int eTextRep,
5466: void *pApp,
5467: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5468: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5469: void (*xFinal)(sqlite3_context*)
5470: );
5471: SQLITE_API int sqlite3_create_function_v2(
5472: sqlite3 *db,
5473: const char *zFunctionName,
5474: int nArg,
5475: int eTextRep,
5476: void *pApp,
5477: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5478: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5479: void (*xFinal)(sqlite3_context*),
5480: void(*xDestroy)(void*)
5481: );
5482: SQLITE_API int sqlite3_create_window_function(
5483: sqlite3 *db,
5484: const char *zFunctionName,
5485: int nArg,
5486: int eTextRep,
5487: void *pApp,
5488: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5489: void (*xFinal)(sqlite3_context*),
5490: void (*xValue)(sqlite3_context*),
5491: void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5492: void(*xDestroy)(void*)
5493: );
5494:
5495: /*
5496: ** CAPI3REF: Text Encodings
5497: **
5498: ** These constant define integer codes that represent the various
5499: ** text encodings supported by SQLite.
5500: */
5501: #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5502: #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5503: #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5504: #define SQLITE_UTF16 4 /* Use native byte order */
5505: #define SQLITE_ANY 5 /* Deprecated */
5506: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5507:
5508: /*
5509: ** CAPI3REF: Function Flags
5510: **
5511: ** These constants may be ORed together with the
5512: ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5513: ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5514: ** [sqlite3_create_function_v2()].
5515: **
5516: ** <dl>
5517: ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5518: ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5519: ** the same output when the input parameters are the same.
5520: ** The [abs|abs() function] is deterministic, for example, but
5521: ** [randomblob|randomblob()] is not. Functions must
5522: ** be deterministic in order to be used in certain contexts such as
5523: ** with the WHERE clause of [partial indexes] or in [generated columns].
5524: ** SQLite might also optimize deterministic functions by factoring them
5525: ** out of inner loops.
5526: ** </dd>
5527: **
5528: ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5529: ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5530: ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5531: ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5532: ** [expression indexes], [partial indexes], or [generated columns].
5533: ** <p>
5534: ** The SQLITE_DIRECTONLY flag is recommended for any
5535: ** [application-defined SQL function]
5536: ** that has side-effects or that could potentially leak sensitive information.
5537: ** This will prevent attacks in which an application is tricked
5538: ** into using a database file that has had its schema surreptitiously
5539: ** modified to invoke the application-defined function in ways that are
5540: ** harmful.
5541: ** <p>
5542: ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5543: ** [application-defined SQL functions], regardless of whether or not they
5544: ** are security sensitive, as doing so prevents those functions from being used
5545: ** inside of the database schema, and thus ensures that the database
5546: ** can be inspected and modified using generic tools (such as the [CLI])
5547: ** that do not have access to the application-defined functions.
5548: ** </dd>
5549: **
5550: ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5551: ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5552: ** to cause problems even if misused. An innocuous function should have
5553: ** no side effects and should not depend on any values other than its
5554: ** input parameters. The [abs|abs() function] is an example of an
5555: ** innocuous function.
5556: ** The [load_extension() SQL function] is not innocuous because of its
5557: ** side effects.
5558: ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5559: ** exactly the same. The [random|random() function] is an example of a
5560: ** function that is innocuous but not deterministic.
5561: ** <p>Some heightened security settings
5562: ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5563: ** disable the use of SQL functions inside views and triggers and in
5564: ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5565: ** [expression indexes], [partial indexes], and [generated columns] unless
5566: ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5567: ** are innocuous. Developers are advised to avoid using the
5568: ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5569: ** function has been carefully audited and found to be free of potentially
5570: ** security-adverse side-effects and information-leaks.
5571: ** </dd>
5572: **
5573: ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5574: ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5575: ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5576: ** Specifying this flag makes no difference for scalar or aggregate user
5577: ** functions. However, if it is not specified for a user-defined window
5578: ** function, then any sub-types belonging to arguments passed to the window
5579: ** function may be discarded before the window function is called (i.e.
5580: ** sqlite3_value_subtype() will always return 0).
5581: ** </dd>
5582: ** </dl>
5583: */
5584: #define SQLITE_DETERMINISTIC 0x000000800
5585: #define SQLITE_DIRECTONLY 0x000080000
5586: #define SQLITE_SUBTYPE 0x000100000
5587: #define SQLITE_INNOCUOUS 0x000200000
5588:
5589: /*
5590: ** CAPI3REF: Deprecated Functions
5591: ** DEPRECATED
5592: **
5593: ** These functions are [deprecated]. In order to maintain
5594: ** backwards compatibility with older code, these functions continue
5595: ** to be supported. However, new applications should avoid
5596: ** the use of these functions. To encourage programmers to avoid
5597: ** these functions, we will not explain what they do.
5598: */
5599: #ifndef SQLITE_OMIT_DEPRECATED
5600: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5601: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5602: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5603: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5604: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5605: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5606: void*,sqlite3_int64);
5607: #endif
5608:
5609: /*
5610: ** CAPI3REF: Obtaining SQL Values
5611: ** METHOD: sqlite3_value
5612: **
5613: ** <b>Summary:</b>
5614: ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5615: ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5616: ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5617: ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5618: ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5619: ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5620: ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5621: ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5622: ** the native byteorder
5623: ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5624: ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5625: ** <tr><td> <td> <td>
5626: ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5627: ** or a UTF-8 TEXT in bytes
5628: ** <tr><td><b>sqlite3_value_bytes16 </b>
5629: ** <td>→ <td>Size of UTF-16
5630: ** TEXT in bytes
5631: ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5632: ** datatype of the value
5633: ** <tr><td><b>sqlite3_value_numeric_type </b>
5634: ** <td>→ <td>Best numeric datatype of the value
5635: ** <tr><td><b>sqlite3_value_nochange </b>
5636: ** <td>→ <td>True if the column is unchanged in an UPDATE
5637: ** against a virtual table.
5638: ** <tr><td><b>sqlite3_value_frombind </b>
5639: ** <td>→ <td>True if value originated from a [bound parameter]
5640: ** </table></blockquote>
5641: **
5642: ** <b>Details:</b>
5643: **
5644: ** These routines extract type, size, and content information from
5645: ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5646: ** are used to pass parameter information into the functions that
5647: ** implement [application-defined SQL functions] and [virtual tables].
5648: **
5649: ** These routines work only with [protected sqlite3_value] objects.
5650: ** Any attempt to use these routines on an [unprotected sqlite3_value]
5651: ** is not threadsafe.
5652: **
5653: ** ^These routines work just like the corresponding [column access functions]
5654: ** except that these routines take a single [protected sqlite3_value] object
5655: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5656: **
5657: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5658: ** in the native byte-order of the host machine. ^The
5659: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5660: ** extract UTF-16 strings as big-endian and little-endian respectively.
5661: **
5662: ** ^If [sqlite3_value] object V was initialized
5663: ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5664: ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5665: ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5666: ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5667: ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5668: **
5669: ** ^(The sqlite3_value_type(V) interface returns the
5670: ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5671: ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5672: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5673: ** Other interfaces might change the datatype for an sqlite3_value object.
5674: ** For example, if the datatype is initially SQLITE_INTEGER and
5675: ** sqlite3_value_text(V) is called to extract a text value for that
5676: ** integer, then subsequent calls to sqlite3_value_type(V) might return
5677: ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5678: ** occurs is undefined and may change from one release of SQLite to the next.
5679: **
5680: ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5681: ** numeric affinity to the value. This means that an attempt is
5682: ** made to convert the value to an integer or floating point. If
5683: ** such a conversion is possible without loss of information (in other
5684: ** words, if the value is a string that looks like a number)
5685: ** then the conversion is performed. Otherwise no conversion occurs.
5686: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5687: **
5688: ** ^Within the [xUpdate] method of a [virtual table], the
5689: ** sqlite3_value_nochange(X) interface returns true if and only if
5690: ** the column corresponding to X is unchanged by the UPDATE operation
5691: ** that the xUpdate method call was invoked to implement and if
5692: ** and the prior [xColumn] method call that was invoked to extracted
5693: ** the value for that column returned without setting a result (probably
5694: ** because it queried [sqlite3_vtab_nochange()] and found that the column
5695: ** was unchanging). ^Within an [xUpdate] method, any value for which
5696: ** sqlite3_value_nochange(X) is true will in all other respects appear
5697: ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5698: ** than within an [xUpdate] method call for an UPDATE statement, then
5699: ** the return value is arbitrary and meaningless.
5700: **
5701: ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5702: ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5703: ** interfaces. ^If X comes from an SQL literal value, or a table column,
5704: ** or an expression, then sqlite3_value_frombind(X) returns zero.
5705: **
5706: ** Please pay particular attention to the fact that the pointer returned
5707: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5708: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5709: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5710: ** or [sqlite3_value_text16()].
5711: **
5712: ** These routines must be called from the same thread as
5713: ** the SQL function that supplied the [sqlite3_value*] parameters.
5714: **
5715: ** As long as the input parameter is correct, these routines can only
5716: ** fail if an out-of-memory error occurs during a format conversion.
5717: ** Only the following subset of interfaces are subject to out-of-memory
5718: ** errors:
5719: **
5720: ** <ul>
5721: ** <li> sqlite3_value_blob()
5722: ** <li> sqlite3_value_text()
5723: ** <li> sqlite3_value_text16()
5724: ** <li> sqlite3_value_text16le()
5725: ** <li> sqlite3_value_text16be()
5726: ** <li> sqlite3_value_bytes()
5727: ** <li> sqlite3_value_bytes16()
5728: ** </ul>
5729: **
5730: ** If an out-of-memory error occurs, then the return value from these
5731: ** routines is the same as if the column had contained an SQL NULL value.
5732: ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5733: ** by invoking the [sqlite3_errcode()] immediately after the suspect
5734: ** return value is obtained and before any
5735: ** other SQLite interface is called on the same [database connection].
5736: */
5737: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5738: SQLITE_API double sqlite3_value_double(sqlite3_value*);
5739: SQLITE_API int sqlite3_value_int(sqlite3_value*);
5740: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5741: SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5742: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5743: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5744: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5745: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5746: SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5747: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5748: SQLITE_API int sqlite3_value_type(sqlite3_value*);
5749: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5750: SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5751: SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5752:
5753: /*
5754: ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5755: ** METHOD: sqlite3_value
5756: **
5757: ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5758: ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
5759: ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5760: ** returns something other than SQLITE_TEXT, then the return value from
5761: ** sqlite3_value_encoding(X) is meaningless. ^Calls to
5762: ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
5763: ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
5764: ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
5765: ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5766: **
5767: ** This routine is intended for used by applications that test and validate
5768: ** the SQLite implementation. This routine is inquiring about the opaque
5769: ** internal state of an [sqlite3_value] object. Ordinary applications should
5770: ** not need to know what the internal state of an sqlite3_value object is and
5771: ** hence should not need to use this interface.
5772: */
5773: SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5774:
5775: /*
5776: ** CAPI3REF: Finding The Subtype Of SQL Values
5777: ** METHOD: sqlite3_value
5778: **
5779: ** The sqlite3_value_subtype(V) function returns the subtype for
5780: ** an [application-defined SQL function] argument V. The subtype
5781: ** information can be used to pass a limited amount of context from
5782: ** one SQL function to another. Use the [sqlite3_result_subtype()]
5783: ** routine to set the subtype for the return value of an SQL function.
5784: */
5785: SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5786:
5787: /*
5788: ** CAPI3REF: Copy And Free SQL Values
5789: ** METHOD: sqlite3_value
5790: **
5791: ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5792: ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5793: ** is a [protected sqlite3_value] object even if the input is not.
5794: ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5795: ** memory allocation fails. ^If V is a [pointer value], then the result
5796: ** of sqlite3_value_dup(V) is a NULL value.
5797: **
5798: ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5799: ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5800: ** then sqlite3_value_free(V) is a harmless no-op.
5801: */
5802: SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5803: SQLITE_API void sqlite3_value_free(sqlite3_value*);
5804:
5805: /*
5806: ** CAPI3REF: Obtain Aggregate Function Context
5807: ** METHOD: sqlite3_context
5808: **
5809: ** Implementations of aggregate SQL functions use this
5810: ** routine to allocate memory for storing their state.
5811: **
5812: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5813: ** for a particular aggregate function, SQLite allocates
5814: ** N bytes of memory, zeroes out that memory, and returns a pointer
5815: ** to the new memory. ^On second and subsequent calls to
5816: ** sqlite3_aggregate_context() for the same aggregate function instance,
5817: ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5818: ** called once for each invocation of the xStep callback and then one
5819: ** last time when the xFinal callback is invoked. ^(When no rows match
5820: ** an aggregate query, the xStep() callback of the aggregate function
5821: ** implementation is never called and xFinal() is called exactly once.
5822: ** In those cases, sqlite3_aggregate_context() might be called for the
5823: ** first time from within xFinal().)^
5824: **
5825: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5826: ** when first called if N is less than or equal to zero or if a memory
5827: ** allocation error occurs.
5828: **
5829: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5830: ** determined by the N parameter on first successful call. Changing the
5831: ** value of N in any subsequent call to sqlite3_aggregate_context() within
5832: ** the same aggregate function instance will not resize the memory
5833: ** allocation.)^ Within the xFinal callback, it is customary to set
5834: ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5835: ** pointless memory allocations occur.
5836: **
5837: ** ^SQLite automatically frees the memory allocated by
5838: ** sqlite3_aggregate_context() when the aggregate query concludes.
5839: **
5840: ** The first parameter must be a copy of the
5841: ** [sqlite3_context | SQL function context] that is the first parameter
5842: ** to the xStep or xFinal callback routine that implements the aggregate
5843: ** function.
5844: **
5845: ** This routine must be called from the same thread in which
5846: ** the aggregate SQL function is running.
5847: */
5848: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5849:
5850: /*
5851: ** CAPI3REF: User Data For Functions
5852: ** METHOD: sqlite3_context
5853: **
5854: ** ^The sqlite3_user_data() interface returns a copy of
5855: ** the pointer that was the pUserData parameter (the 5th parameter)
5856: ** of the [sqlite3_create_function()]
5857: ** and [sqlite3_create_function16()] routines that originally
5858: ** registered the application defined function.
5859: **
5860: ** This routine must be called from the same thread in which
5861: ** the application-defined function is running.
5862: */
5863: SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5864:
5865: /*
5866: ** CAPI3REF: Database Connection For Functions
5867: ** METHOD: sqlite3_context
5868: **
5869: ** ^The sqlite3_context_db_handle() interface returns a copy of
5870: ** the pointer to the [database connection] (the 1st parameter)
5871: ** of the [sqlite3_create_function()]
5872: ** and [sqlite3_create_function16()] routines that originally
5873: ** registered the application defined function.
5874: */
5875: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5876:
5877: /*
5878: ** CAPI3REF: Function Auxiliary Data
5879: ** METHOD: sqlite3_context
5880: **
5881: ** These functions may be used by (non-aggregate) SQL functions to
5882: ** associate metadata with argument values. If the same value is passed to
5883: ** multiple invocations of the same SQL function during query execution, under
5884: ** some circumstances the associated metadata may be preserved. An example
5885: ** of where this might be useful is in a regular-expression matching
5886: ** function. The compiled version of the regular expression can be stored as
5887: ** metadata associated with the pattern string.
5888: ** Then as long as the pattern string remains the same,
5889: ** the compiled regular expression can be reused on multiple
5890: ** invocations of the same function.
5891: **
5892: ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5893: ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5894: ** value to the application-defined function. ^N is zero for the left-most
5895: ** function argument. ^If there is no metadata
5896: ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5897: ** returns a NULL pointer.
5898: **
5899: ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5900: ** argument of the application-defined function. ^Subsequent
5901: ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5902: ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5903: ** NULL if the metadata has been discarded.
5904: ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5905: ** SQLite will invoke the destructor function X with parameter P exactly
5906: ** once, when the metadata is discarded.
5907: ** SQLite is free to discard the metadata at any time, including: <ul>
5908: ** <li> ^(when the corresponding function parameter changes)^, or
5909: ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5910: ** SQL statement)^, or
5911: ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5912: ** parameter)^, or
5913: ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5914: ** allocation error occurs.)^ </ul>
5915: **
5916: ** Note the last bullet in particular. The destructor X in
5917: ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5918: ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5919: ** should be called near the end of the function implementation and the
5920: ** function implementation should not make any use of P after
5921: ** sqlite3_set_auxdata() has been called.
5922: **
5923: ** ^(In practice, metadata is preserved between function calls for
5924: ** function parameters that are compile-time constants, including literal
5925: ** values and [parameters] and expressions composed from the same.)^
5926: **
5927: ** The value of the N parameter to these interfaces should be non-negative.
5928: ** Future enhancements may make use of negative N values to define new
5929: ** kinds of function caching behavior.
5930: **
5931: ** These routines must be called from the same thread in which
5932: ** the SQL function is running.
5933: */
5934: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5935: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5936:
5937:
5938: /*
5939: ** CAPI3REF: Constants Defining Special Destructor Behavior
5940: **
5941: ** These are special values for the destructor that is passed in as the
5942: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5943: ** argument is SQLITE_STATIC, it means that the content pointer is constant
5944: ** and will never change. It does not need to be destroyed. ^The
5945: ** SQLITE_TRANSIENT value means that the content will likely change in
5946: ** the near future and that SQLite should make its own private copy of
5947: ** the content before returning.
5948: **
5949: ** The typedef is necessary to work around problems in certain
5950: ** C++ compilers.
5951: */
5952: typedef void (*sqlite3_destructor_type)(void*);
5953: #define SQLITE_STATIC ((sqlite3_destructor_type)0)
5954: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5955:
5956: /*
5957: ** CAPI3REF: Setting The Result Of An SQL Function
5958: ** METHOD: sqlite3_context
5959: **
5960: ** These routines are used by the xFunc or xFinal callbacks that
5961: ** implement SQL functions and aggregates. See
5962: ** [sqlite3_create_function()] and [sqlite3_create_function16()]
5963: ** for additional information.
5964: **
5965: ** These functions work very much like the [parameter binding] family of
5966: ** functions used to bind values to host parameters in prepared statements.
5967: ** Refer to the [SQL parameter] documentation for additional information.
5968: **
5969: ** ^The sqlite3_result_blob() interface sets the result from
5970: ** an application-defined function to be the BLOB whose content is pointed
5971: ** to by the second parameter and which is N bytes long where N is the
5972: ** third parameter.
5973: **
5974: ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5975: ** interfaces set the result of the application-defined function to be
5976: ** a BLOB containing all zero bytes and N bytes in size.
5977: **
5978: ** ^The sqlite3_result_double() interface sets the result from
5979: ** an application-defined function to be a floating point value specified
5980: ** by its 2nd argument.
5981: **
5982: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5983: ** cause the implemented SQL function to throw an exception.
5984: ** ^SQLite uses the string pointed to by the
5985: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5986: ** as the text of an error message. ^SQLite interprets the error
5987: ** message string from sqlite3_result_error() as UTF-8. ^SQLite
5988: ** interprets the string from sqlite3_result_error16() as UTF-16 using
5989: ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5990: ** ^If the third parameter to sqlite3_result_error()
5991: ** or sqlite3_result_error16() is negative then SQLite takes as the error
5992: ** message all text up through the first zero character.
5993: ** ^If the third parameter to sqlite3_result_error() or
5994: ** sqlite3_result_error16() is non-negative then SQLite takes that many
5995: ** bytes (not characters) from the 2nd parameter as the error message.
5996: ** ^The sqlite3_result_error() and sqlite3_result_error16()
5997: ** routines make a private copy of the error message text before
5998: ** they return. Hence, the calling function can deallocate or
5999: ** modify the text after they return without harm.
6000: ** ^The sqlite3_result_error_code() function changes the error code
6001: ** returned by SQLite as a result of an error in a function. ^By default,
6002: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6003: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6004: **
6005: ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6006: ** error indicating that a string or BLOB is too long to represent.
6007: **
6008: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6009: ** error indicating that a memory allocation failed.
6010: **
6011: ** ^The sqlite3_result_int() interface sets the return value
6012: ** of the application-defined function to be the 32-bit signed integer
6013: ** value given in the 2nd argument.
6014: ** ^The sqlite3_result_int64() interface sets the return value
6015: ** of the application-defined function to be the 64-bit signed integer
6016: ** value given in the 2nd argument.
6017: **
6018: ** ^The sqlite3_result_null() interface sets the return value
6019: ** of the application-defined function to be NULL.
6020: **
6021: ** ^The sqlite3_result_text(), sqlite3_result_text16(),
6022: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6023: ** set the return value of the application-defined function to be
6024: ** a text string which is represented as UTF-8, UTF-16 native byte order,
6025: ** UTF-16 little endian, or UTF-16 big endian, respectively.
6026: ** ^The sqlite3_result_text64() interface sets the return value of an
6027: ** application-defined function to be a text string in an encoding
6028: ** specified by the fifth (and last) parameter, which must be one
6029: ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6030: ** ^SQLite takes the text result from the application from
6031: ** the 2nd parameter of the sqlite3_result_text* interfaces.
6032: ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6033: ** other than sqlite3_result_text64() is negative, then SQLite computes
6034: ** the string length itself by searching the 2nd parameter for the first
6035: ** zero character.
6036: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6037: ** is non-negative, then as many bytes (not characters) of the text
6038: ** pointed to by the 2nd parameter are taken as the application-defined
6039: ** function result. If the 3rd parameter is non-negative, then it
6040: ** must be the byte offset into the string where the NUL terminator would
6041: ** appear if the string where NUL terminated. If any NUL characters occur
6042: ** in the string at a byte offset that is less than the value of the 3rd
6043: ** parameter, then the resulting string will contain embedded NULs and the
6044: ** result of expressions operating on strings with embedded NULs is undefined.
6045: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6046: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6047: ** function as the destructor on the text or BLOB result when it has
6048: ** finished using that result.
6049: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6050: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6051: ** assumes that the text or BLOB result is in constant space and does not
6052: ** copy the content of the parameter nor call a destructor on the content
6053: ** when it has finished using that result.
6054: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6055: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6056: ** then SQLite makes a copy of the result into space obtained
6057: ** from [sqlite3_malloc()] before it returns.
6058: **
6059: ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6060: ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6061: ** when the encoding is not UTF8, if the input UTF16 begins with a
6062: ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6063: ** string and the rest of the string is interpreted according to the
6064: ** byte-order specified by the BOM. ^The byte-order specified by
6065: ** the BOM at the beginning of the text overrides the byte-order
6066: ** specified by the interface procedure. ^So, for example, if
6067: ** sqlite3_result_text16le() is invoked with text that begins
6068: ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6069: ** first two bytes of input are skipped and the remaining input
6070: ** is interpreted as UTF16BE text.
6071: **
6072: ** ^For UTF16 input text to the sqlite3_result_text16(),
6073: ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6074: ** sqlite3_result_text64() routines, if the text contains invalid
6075: ** UTF16 characters, the invalid characters might be converted
6076: ** into the unicode replacement character, U+FFFD.
6077: **
6078: ** ^The sqlite3_result_value() interface sets the result of
6079: ** the application-defined function to be a copy of the
6080: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6081: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6082: ** so that the [sqlite3_value] specified in the parameter may change or
6083: ** be deallocated after sqlite3_result_value() returns without harm.
6084: ** ^A [protected sqlite3_value] object may always be used where an
6085: ** [unprotected sqlite3_value] object is required, so either
6086: ** kind of [sqlite3_value] object can be used with this interface.
6087: **
6088: ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6089: ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6090: ** also associates the host-language pointer P or type T with that
6091: ** NULL value such that the pointer can be retrieved within an
6092: ** [application-defined SQL function] using [sqlite3_value_pointer()].
6093: ** ^If the D parameter is not NULL, then it is a pointer to a destructor
6094: ** for the P parameter. ^SQLite invokes D with P as its only argument
6095: ** when SQLite is finished with P. The T parameter should be a static
6096: ** string and preferably a string literal. The sqlite3_result_pointer()
6097: ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6098: **
6099: ** If these routines are called from within the different thread
6100: ** than the one containing the application-defined function that received
6101: ** the [sqlite3_context] pointer, the results are undefined.
6102: */
6103: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6104: SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6105: sqlite3_uint64,void(*)(void*));
6106: SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6107: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6108: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6109: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6110: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6111: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6112: SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6113: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6114: SQLITE_API void sqlite3_result_null(sqlite3_context*);
6115: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6116: SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6117: void(*)(void*), unsigned char encoding);
6118: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6119: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6120: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6121: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6122: SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6123: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6124: SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6125:
6126:
6127: /*
6128: ** CAPI3REF: Setting The Subtype Of An SQL Function
6129: ** METHOD: sqlite3_context
6130: **
6131: ** The sqlite3_result_subtype(C,T) function causes the subtype of
6132: ** the result from the [application-defined SQL function] with
6133: ** [sqlite3_context] C to be the value T. Only the lower 8 bits
6134: ** of the subtype T are preserved in current versions of SQLite;
6135: ** higher order bits are discarded.
6136: ** The number of subtype bytes preserved by SQLite might increase
6137: ** in future releases of SQLite.
6138: */
6139: SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6140:
6141: /*
6142: ** CAPI3REF: Define New Collating Sequences
6143: ** METHOD: sqlite3
6144: **
6145: ** ^These functions add, remove, or modify a [collation] associated
6146: ** with the [database connection] specified as the first argument.
6147: **
6148: ** ^The name of the collation is a UTF-8 string
6149: ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6150: ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6151: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6152: ** considered to be the same name.
6153: **
6154: ** ^(The third argument (eTextRep) must be one of the constants:
6155: ** <ul>
6156: ** <li> [SQLITE_UTF8],
6157: ** <li> [SQLITE_UTF16LE],
6158: ** <li> [SQLITE_UTF16BE],
6159: ** <li> [SQLITE_UTF16], or
6160: ** <li> [SQLITE_UTF16_ALIGNED].
6161: ** </ul>)^
6162: ** ^The eTextRep argument determines the encoding of strings passed
6163: ** to the collating function callback, xCompare.
6164: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6165: ** force strings to be UTF16 with native byte order.
6166: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6167: ** on an even byte address.
6168: **
6169: ** ^The fourth argument, pArg, is an application data pointer that is passed
6170: ** through as the first argument to the collating function callback.
6171: **
6172: ** ^The fifth argument, xCompare, is a pointer to the collating function.
6173: ** ^Multiple collating functions can be registered using the same name but
6174: ** with different eTextRep parameters and SQLite will use whichever
6175: ** function requires the least amount of data transformation.
6176: ** ^If the xCompare argument is NULL then the collating function is
6177: ** deleted. ^When all collating functions having the same name are deleted,
6178: ** that collation is no longer usable.
6179: **
6180: ** ^The collating function callback is invoked with a copy of the pArg
6181: ** application data pointer and with two strings in the encoding specified
6182: ** by the eTextRep argument. The two integer parameters to the collating
6183: ** function callback are the length of the two strings, in bytes. The collating
6184: ** function must return an integer that is negative, zero, or positive
6185: ** if the first string is less than, equal to, or greater than the second,
6186: ** respectively. A collating function must always return the same answer
6187: ** given the same inputs. If two or more collating functions are registered
6188: ** to the same collation name (using different eTextRep values) then all
6189: ** must give an equivalent answer when invoked with equivalent strings.
6190: ** The collating function must obey the following properties for all
6191: ** strings A, B, and C:
6192: **
6193: ** <ol>
6194: ** <li> If A==B then B==A.
6195: ** <li> If A==B and B==C then A==C.
6196: ** <li> If A<B THEN B>A.
6197: ** <li> If A<B and B<C then A<C.
6198: ** </ol>
6199: **
6200: ** If a collating function fails any of the above constraints and that
6201: ** collating function is registered and used, then the behavior of SQLite
6202: ** is undefined.
6203: **
6204: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6205: ** with the addition that the xDestroy callback is invoked on pArg when
6206: ** the collating function is deleted.
6207: ** ^Collating functions are deleted when they are overridden by later
6208: ** calls to the collation creation functions or when the
6209: ** [database connection] is closed using [sqlite3_close()].
6210: **
6211: ** ^The xDestroy callback is <u>not</u> called if the
6212: ** sqlite3_create_collation_v2() function fails. Applications that invoke
6213: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6214: ** check the return code and dispose of the application data pointer
6215: ** themselves rather than expecting SQLite to deal with it for them.
6216: ** This is different from every other SQLite interface. The inconsistency
6217: ** is unfortunate but cannot be changed without breaking backwards
6218: ** compatibility.
6219: **
6220: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6221: */
6222: SQLITE_API int sqlite3_create_collation(
6223: sqlite3*,
6224: const char *zName,
6225: int eTextRep,
6226: void *pArg,
6227: int(*xCompare)(void*,int,const void*,int,const void*)
6228: );
6229: SQLITE_API int sqlite3_create_collation_v2(
6230: sqlite3*,
6231: const char *zName,
6232: int eTextRep,
6233: void *pArg,
6234: int(*xCompare)(void*,int,const void*,int,const void*),
6235: void(*xDestroy)(void*)
6236: );
6237: SQLITE_API int sqlite3_create_collation16(
6238: sqlite3*,
6239: const void *zName,
6240: int eTextRep,
6241: void *pArg,
6242: int(*xCompare)(void*,int,const void*,int,const void*)
6243: );
6244:
6245: /*
6246: ** CAPI3REF: Collation Needed Callbacks
6247: ** METHOD: sqlite3
6248: **
6249: ** ^To avoid having to register all collation sequences before a database
6250: ** can be used, a single callback function may be registered with the
6251: ** [database connection] to be invoked whenever an undefined collation
6252: ** sequence is required.
6253: **
6254: ** ^If the function is registered using the sqlite3_collation_needed() API,
6255: ** then it is passed the names of undefined collation sequences as strings
6256: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6257: ** the names are passed as UTF-16 in machine native byte order.
6258: ** ^A call to either function replaces the existing collation-needed callback.
6259: **
6260: ** ^(When the callback is invoked, the first argument passed is a copy
6261: ** of the second argument to sqlite3_collation_needed() or
6262: ** sqlite3_collation_needed16(). The second argument is the database
6263: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6264: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6265: ** sequence function required. The fourth parameter is the name of the
6266: ** required collation sequence.)^
6267: **
6268: ** The callback function should register the desired collation using
6269: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6270: ** [sqlite3_create_collation_v2()].
6271: */
6272: SQLITE_API int sqlite3_collation_needed(
6273: sqlite3*,
6274: void*,
6275: void(*)(void*,sqlite3*,int eTextRep,const char*)
6276: );
6277: SQLITE_API int sqlite3_collation_needed16(
6278: sqlite3*,
6279: void*,
6280: void(*)(void*,sqlite3*,int eTextRep,const void*)
6281: );
6282:
6283: #ifdef SQLITE_ENABLE_CEROD
6284: /*
6285: ** Specify the activation key for a CEROD database. Unless
6286: ** activated, none of the CEROD routines will work.
6287: */
6288: SQLITE_API void sqlite3_activate_cerod(
6289: const char *zPassPhrase /* Activation phrase */
6290: );
6291: #endif
6292:
6293: /*
6294: ** CAPI3REF: Suspend Execution For A Short Time
6295: **
6296: ** The sqlite3_sleep() function causes the current thread to suspend execution
6297: ** for at least a number of milliseconds specified in its parameter.
6298: **
6299: ** If the operating system does not support sleep requests with
6300: ** millisecond time resolution, then the time will be rounded up to
6301: ** the nearest second. The number of milliseconds of sleep actually
6302: ** requested from the operating system is returned.
6303: **
6304: ** ^SQLite implements this interface by calling the xSleep()
6305: ** method of the default [sqlite3_vfs] object. If the xSleep() method
6306: ** of the default VFS is not implemented correctly, or not implemented at
6307: ** all, then the behavior of sqlite3_sleep() may deviate from the description
6308: ** in the previous paragraphs.
6309: **
6310: ** If a negative argument is passed to sqlite3_sleep() the results vary by
6311: ** VFS and operating system. Some system treat a negative argument as an
6312: ** instruction to sleep forever. Others understand it to mean do not sleep
6313: ** at all. ^In SQLite version 3.42.0 and later, a negative
6314: ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6315: ** down into the xSleep method of the VFS.
6316: */
6317: SQLITE_API int sqlite3_sleep(int);
6318:
6319: /*
6320: ** CAPI3REF: Name Of The Folder Holding Temporary Files
6321: **
6322: ** ^(If this global variable is made to point to a string which is
6323: ** the name of a folder (a.k.a. directory), then all temporary files
6324: ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6325: ** will be placed in that directory.)^ ^If this variable
6326: ** is a NULL pointer, then SQLite performs a search for an appropriate
6327: ** temporary file directory.
6328: **
6329: ** Applications are strongly discouraged from using this global variable.
6330: ** It is required to set a temporary folder on Windows Runtime (WinRT).
6331: ** But for all other platforms, it is highly recommended that applications
6332: ** neither read nor write this variable. This global variable is a relic
6333: ** that exists for backwards compatibility of legacy applications and should
6334: ** be avoided in new projects.
6335: **
6336: ** It is not safe to read or modify this variable in more than one
6337: ** thread at a time. It is not safe to read or modify this variable
6338: ** if a [database connection] is being used at the same time in a separate
6339: ** thread.
6340: ** It is intended that this variable be set once
6341: ** as part of process initialization and before any SQLite interface
6342: ** routines have been called and that this variable remain unchanged
6343: ** thereafter.
6344: **
6345: ** ^The [temp_store_directory pragma] may modify this variable and cause
6346: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6347: ** the [temp_store_directory pragma] always assumes that any string
6348: ** that this variable points to is held in memory obtained from
6349: ** [sqlite3_malloc] and the pragma may attempt to free that memory
6350: ** using [sqlite3_free].
6351: ** Hence, if this variable is modified directly, either it should be
6352: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6353: ** or else the use of the [temp_store_directory pragma] should be avoided.
6354: ** Except when requested by the [temp_store_directory pragma], SQLite
6355: ** does not free the memory that sqlite3_temp_directory points to. If
6356: ** the application wants that memory to be freed, it must do
6357: ** so itself, taking care to only do so after all [database connection]
6358: ** objects have been destroyed.
6359: **
6360: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6361: ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6362: ** features that require the use of temporary files may fail. Here is an
6363: ** example of how to do this using C++ with the Windows Runtime:
6364: **
6365: ** <blockquote><pre>
6366: ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6367: ** TemporaryFolder->Path->Data();
6368: ** char zPathBuf[MAX_PATH + 1];
6369: ** memset(zPathBuf, 0, sizeof(zPathBuf));
6370: ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6371: ** NULL, NULL);
6372: ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6373: ** </pre></blockquote>
6374: */
6375: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6376:
6377: /*
6378: ** CAPI3REF: Name Of The Folder Holding Database Files
6379: **
6380: ** ^(If this global variable is made to point to a string which is
6381: ** the name of a folder (a.k.a. directory), then all database files
6382: ** specified with a relative pathname and created or accessed by
6383: ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6384: ** to be relative to that directory.)^ ^If this variable is a NULL
6385: ** pointer, then SQLite assumes that all database files specified
6386: ** with a relative pathname are relative to the current directory
6387: ** for the process. Only the windows VFS makes use of this global
6388: ** variable; it is ignored by the unix VFS.
6389: **
6390: ** Changing the value of this variable while a database connection is
6391: ** open can result in a corrupt database.
6392: **
6393: ** It is not safe to read or modify this variable in more than one
6394: ** thread at a time. It is not safe to read or modify this variable
6395: ** if a [database connection] is being used at the same time in a separate
6396: ** thread.
6397: ** It is intended that this variable be set once
6398: ** as part of process initialization and before any SQLite interface
6399: ** routines have been called and that this variable remain unchanged
6400: ** thereafter.
6401: **
6402: ** ^The [data_store_directory pragma] may modify this variable and cause
6403: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6404: ** the [data_store_directory pragma] always assumes that any string
6405: ** that this variable points to is held in memory obtained from
6406: ** [sqlite3_malloc] and the pragma may attempt to free that memory
6407: ** using [sqlite3_free].
6408: ** Hence, if this variable is modified directly, either it should be
6409: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6410: ** or else the use of the [data_store_directory pragma] should be avoided.
6411: */
6412: SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6413:
6414: /*
6415: ** CAPI3REF: Win32 Specific Interface
6416: **
6417: ** These interfaces are available only on Windows. The
6418: ** [sqlite3_win32_set_directory] interface is used to set the value associated
6419: ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6420: ** zValue, depending on the value of the type parameter. The zValue parameter
6421: ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6422: ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6423: ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6424: ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6425: ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6426: ** [sqlite3_data_directory] variable is intended to act as a replacement for
6427: ** the current directory on the sub-platforms of Win32 where that concept is
6428: ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6429: ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6430: ** sqlite3_win32_set_directory interface except the string parameter must be
6431: ** UTF-8 or UTF-16, respectively.
6432: */
6433: SQLITE_API int sqlite3_win32_set_directory(
6434: unsigned long type, /* Identifier for directory being set or reset */
6435: void *zValue /* New value for directory being set or reset */
6436: );
6437: SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6438: SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6439:
6440: /*
6441: ** CAPI3REF: Win32 Directory Types
6442: **
6443: ** These macros are only available on Windows. They define the allowed values
6444: ** for the type argument to the [sqlite3_win32_set_directory] interface.
6445: */
6446: #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6447: #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6448:
6449: /*
6450: ** CAPI3REF: Test For Auto-Commit Mode
6451: ** KEYWORDS: {autocommit mode}
6452: ** METHOD: sqlite3
6453: **
6454: ** ^The sqlite3_get_autocommit() interface returns non-zero or
6455: ** zero if the given database connection is or is not in autocommit mode,
6456: ** respectively. ^Autocommit mode is on by default.
6457: ** ^Autocommit mode is disabled by a [BEGIN] statement.
6458: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6459: **
6460: ** If certain kinds of errors occur on a statement within a multi-statement
6461: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6462: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6463: ** transaction might be rolled back automatically. The only way to
6464: ** find out whether SQLite automatically rolled back the transaction after
6465: ** an error is to use this function.
6466: **
6467: ** If another thread changes the autocommit status of the database
6468: ** connection while this routine is running, then the return value
6469: ** is undefined.
6470: */
6471: SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6472:
6473: /*
6474: ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6475: ** METHOD: sqlite3_stmt
6476: **
6477: ** ^The sqlite3_db_handle interface returns the [database connection] handle
6478: ** to which a [prepared statement] belongs. ^The [database connection]
6479: ** returned by sqlite3_db_handle is the same [database connection]
6480: ** that was the first argument
6481: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6482: ** create the statement in the first place.
6483: */
6484: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6485:
6486: /*
6487: ** CAPI3REF: Return The Schema Name For A Database Connection
6488: ** METHOD: sqlite3
6489: **
6490: ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6491: ** for the N-th database on database connection D, or a NULL pointer of N is
6492: ** out of range. An N value of 0 means the main database file. An N of 1 is
6493: ** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6494: ** databases.
6495: **
6496: ** Space to hold the string that is returned by sqlite3_db_name() is managed
6497: ** by SQLite itself. The string might be deallocated by any operation that
6498: ** changes the schema, including [ATTACH] or [DETACH] or calls to
6499: ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6500: ** occur on a different thread. Applications that need to
6501: ** remember the string long-term should make their own copy. Applications that
6502: ** are accessing the same database connection simultaneously on multiple
6503: ** threads should mutex-protect calls to this API and should make their own
6504: ** private copy of the result prior to releasing the mutex.
6505: */
6506: SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6507:
6508: /*
6509: ** CAPI3REF: Return The Filename For A Database Connection
6510: ** METHOD: sqlite3
6511: **
6512: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6513: ** associated with database N of connection D.
6514: ** ^If there is no attached database N on the database
6515: ** connection D, or if database N is a temporary or in-memory database, then
6516: ** this function will return either a NULL pointer or an empty string.
6517: **
6518: ** ^The string value returned by this routine is owned and managed by
6519: ** the database connection. ^The value will be valid until the database N
6520: ** is [DETACH]-ed or until the database connection closes.
6521: **
6522: ** ^The filename returned by this function is the output of the
6523: ** xFullPathname method of the [VFS]. ^In other words, the filename
6524: ** will be an absolute pathname, even if the filename used
6525: ** to open the database originally was a URI or relative pathname.
6526: **
6527: ** If the filename pointer returned by this routine is not NULL, then it
6528: ** can be used as the filename input parameter to these routines:
6529: ** <ul>
6530: ** <li> [sqlite3_uri_parameter()]
6531: ** <li> [sqlite3_uri_boolean()]
6532: ** <li> [sqlite3_uri_int64()]
6533: ** <li> [sqlite3_filename_database()]
6534: ** <li> [sqlite3_filename_journal()]
6535: ** <li> [sqlite3_filename_wal()]
6536: ** </ul>
6537: */
6538: SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6539:
6540: /*
6541: ** CAPI3REF: Determine if a database is read-only
6542: ** METHOD: sqlite3
6543: **
6544: ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6545: ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6546: ** the name of a database on connection D.
6547: */
6548: SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6549:
6550: /*
6551: ** CAPI3REF: Determine the transaction state of a database
6552: ** METHOD: sqlite3
6553: **
6554: ** ^The sqlite3_txn_state(D,S) interface returns the current
6555: ** [transaction state] of schema S in database connection D. ^If S is NULL,
6556: ** then the highest transaction state of any schema on database connection D
6557: ** is returned. Transaction states are (in order of lowest to highest):
6558: ** <ol>
6559: ** <li value="0"> SQLITE_TXN_NONE
6560: ** <li value="1"> SQLITE_TXN_READ
6561: ** <li value="2"> SQLITE_TXN_WRITE
6562: ** </ol>
6563: ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6564: ** a valid schema, then -1 is returned.
6565: */
6566: SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6567:
6568: /*
6569: ** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6570: ** KEYWORDS: {transaction state}
6571: **
6572: ** These constants define the current transaction state of a database file.
6573: ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6574: ** constants in order to describe the transaction state of schema S
6575: ** in [database connection] D.
6576: **
6577: ** <dl>
6578: ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6579: ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6580: ** pending.</dd>
6581: **
6582: ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6583: ** <dd>The SQLITE_TXN_READ state means that the database is currently
6584: ** in a read transaction. Content has been read from the database file
6585: ** but nothing in the database file has changed. The transaction state
6586: ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6587: ** no other conflicting concurrent write transactions. The transaction
6588: ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6589: ** [COMMIT].</dd>
6590: **
6591: ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6592: ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6593: ** in a write transaction. Content has been written to the database file
6594: ** but has not yet committed. The transaction state will change to
6595: ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6596: */
6597: #define SQLITE_TXN_NONE 0
6598: #define SQLITE_TXN_READ 1
6599: #define SQLITE_TXN_WRITE 2
6600:
6601: /*
6602: ** CAPI3REF: Find the next prepared statement
6603: ** METHOD: sqlite3
6604: **
6605: ** ^This interface returns a pointer to the next [prepared statement] after
6606: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6607: ** then this interface returns a pointer to the first prepared statement
6608: ** associated with the database connection pDb. ^If no prepared statement
6609: ** satisfies the conditions of this routine, it returns NULL.
6610: **
6611: ** The [database connection] pointer D in a call to
6612: ** [sqlite3_next_stmt(D,S)] must refer to an open database
6613: ** connection and in particular must not be a NULL pointer.
6614: */
6615: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6616:
6617: /*
6618: ** CAPI3REF: Commit And Rollback Notification Callbacks
6619: ** METHOD: sqlite3
6620: **
6621: ** ^The sqlite3_commit_hook() interface registers a callback
6622: ** function to be invoked whenever a transaction is [COMMIT | committed].
6623: ** ^Any callback set by a previous call to sqlite3_commit_hook()
6624: ** for the same database connection is overridden.
6625: ** ^The sqlite3_rollback_hook() interface registers a callback
6626: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6627: ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6628: ** for the same database connection is overridden.
6629: ** ^The pArg argument is passed through to the callback.
6630: ** ^If the callback on a commit hook function returns non-zero,
6631: ** then the commit is converted into a rollback.
6632: **
6633: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6634: ** return the P argument from the previous call of the same function
6635: ** on the same [database connection] D, or NULL for
6636: ** the first call for each function on D.
6637: **
6638: ** The commit and rollback hook callbacks are not reentrant.
6639: ** The callback implementation must not do anything that will modify
6640: ** the database connection that invoked the callback. Any actions
6641: ** to modify the database connection must be deferred until after the
6642: ** completion of the [sqlite3_step()] call that triggered the commit
6643: ** or rollback hook in the first place.
6644: ** Note that running any other SQL statements, including SELECT statements,
6645: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6646: ** the database connections for the meaning of "modify" in this paragraph.
6647: **
6648: ** ^Registering a NULL function disables the callback.
6649: **
6650: ** ^When the commit hook callback routine returns zero, the [COMMIT]
6651: ** operation is allowed to continue normally. ^If the commit hook
6652: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6653: ** ^The rollback hook is invoked on a rollback that results from a commit
6654: ** hook returning non-zero, just as it would be with any other rollback.
6655: **
6656: ** ^For the purposes of this API, a transaction is said to have been
6657: ** rolled back if an explicit "ROLLBACK" statement is executed, or
6658: ** an error or constraint causes an implicit rollback to occur.
6659: ** ^The rollback callback is not invoked if a transaction is
6660: ** automatically rolled back because the database connection is closed.
6661: **
6662: ** See also the [sqlite3_update_hook()] interface.
6663: */
6664: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6665: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6666:
6667: /*
6668: ** CAPI3REF: Autovacuum Compaction Amount Callback
6669: ** METHOD: sqlite3
6670: **
6671: ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6672: ** function C that is invoked prior to each autovacuum of the database
6673: ** file. ^The callback is passed a copy of the generic data pointer (P),
6674: ** the schema-name of the attached database that is being autovacuumed,
6675: ** the size of the database file in pages, the number of free pages,
6676: ** and the number of bytes per page, respectively. The callback should
6677: ** return the number of free pages that should be removed by the
6678: ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6679: ** ^If the value returned is greater than or equal to the number of
6680: ** free pages, then a complete autovacuum happens.
6681: **
6682: ** <p>^If there are multiple ATTACH-ed database files that are being
6683: ** modified as part of a transaction commit, then the autovacuum pages
6684: ** callback is invoked separately for each file.
6685: **
6686: ** <p><b>The callback is not reentrant.</b> The callback function should
6687: ** not attempt to invoke any other SQLite interface. If it does, bad
6688: ** things may happen, including segmentation faults and corrupt database
6689: ** files. The callback function should be a simple function that
6690: ** does some arithmetic on its input parameters and returns a result.
6691: **
6692: ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6693: ** destructor for the P parameter. ^If X is not NULL, then X(P) is
6694: ** invoked whenever the database connection closes or when the callback
6695: ** is overwritten by another invocation of sqlite3_autovacuum_pages().
6696: **
6697: ** <p>^There is only one autovacuum pages callback per database connection.
6698: ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6699: ** previous invocations for that database connection. ^If the callback
6700: ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6701: ** then the autovacuum steps callback is cancelled. The return value
6702: ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6703: ** be some other error code if something goes wrong. The current
6704: ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6705: ** return codes might be added in future releases.
6706: **
6707: ** <p>If no autovacuum pages callback is specified (the usual case) or
6708: ** a NULL pointer is provided for the callback,
6709: ** then the default behavior is to vacuum all free pages. So, in other
6710: ** words, the default behavior is the same as if the callback function
6711: ** were something like this:
6712: **
6713: ** <blockquote><pre>
6714: ** unsigned int demonstration_autovac_pages_callback(
6715: ** void *pClientData,
6716: ** const char *zSchema,
6717: ** unsigned int nDbPage,
6718: ** unsigned int nFreePage,
6719: ** unsigned int nBytePerPage
6720: ** ){
6721: ** return nFreePage;
6722: ** }
6723: ** </pre></blockquote>
6724: */
6725: SQLITE_API int sqlite3_autovacuum_pages(
6726: sqlite3 *db,
6727: unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6728: void*,
6729: void(*)(void*)
6730: );
6731:
6732:
6733: /*
6734: ** CAPI3REF: Data Change Notification Callbacks
6735: ** METHOD: sqlite3
6736: **
6737: ** ^The sqlite3_update_hook() interface registers a callback function
6738: ** with the [database connection] identified by the first argument
6739: ** to be invoked whenever a row is updated, inserted or deleted in
6740: ** a [rowid table].
6741: ** ^Any callback set by a previous call to this function
6742: ** for the same database connection is overridden.
6743: **
6744: ** ^The second argument is a pointer to the function to invoke when a
6745: ** row is updated, inserted or deleted in a rowid table.
6746: ** ^The first argument to the callback is a copy of the third argument
6747: ** to sqlite3_update_hook().
6748: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6749: ** or [SQLITE_UPDATE], depending on the operation that caused the callback
6750: ** to be invoked.
6751: ** ^The third and fourth arguments to the callback contain pointers to the
6752: ** database and table name containing the affected row.
6753: ** ^The final callback parameter is the [rowid] of the row.
6754: ** ^In the case of an update, this is the [rowid] after the update takes place.
6755: **
6756: ** ^(The update hook is not invoked when internal system tables are
6757: ** modified (i.e. sqlite_sequence).)^
6758: ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6759: **
6760: ** ^In the current implementation, the update hook
6761: ** is not invoked when conflicting rows are deleted because of an
6762: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6763: ** invoked when rows are deleted using the [truncate optimization].
6764: ** The exceptions defined in this paragraph might change in a future
6765: ** release of SQLite.
6766: **
6767: ** The update hook implementation must not do anything that will modify
6768: ** the database connection that invoked the update hook. Any actions
6769: ** to modify the database connection must be deferred until after the
6770: ** completion of the [sqlite3_step()] call that triggered the update hook.
6771: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6772: ** database connections for the meaning of "modify" in this paragraph.
6773: **
6774: ** ^The sqlite3_update_hook(D,C,P) function
6775: ** returns the P argument from the previous call
6776: ** on the same [database connection] D, or NULL for
6777: ** the first call on D.
6778: **
6779: ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6780: ** and [sqlite3_preupdate_hook()] interfaces.
6781: */
6782: SQLITE_API void *sqlite3_update_hook(
6783: sqlite3*,
6784: void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6785: void*
6786: );
6787:
6788: /*
6789: ** CAPI3REF: Enable Or Disable Shared Pager Cache
6790: **
6791: ** ^(This routine enables or disables the sharing of the database cache
6792: ** and schema data structures between [database connection | connections]
6793: ** to the same database. Sharing is enabled if the argument is true
6794: ** and disabled if the argument is false.)^
6795: **
6796: ** This interface is omitted if SQLite is compiled with
6797: ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6798: ** compile-time option is recommended because the
6799: ** [use of shared cache mode is discouraged].
6800: **
6801: ** ^Cache sharing is enabled and disabled for an entire process.
6802: ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6803: ** In prior versions of SQLite,
6804: ** sharing was enabled or disabled for each thread separately.
6805: **
6806: ** ^(The cache sharing mode set by this interface effects all subsequent
6807: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6808: ** Existing database connections continue to use the sharing mode
6809: ** that was in effect at the time they were opened.)^
6810: **
6811: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6812: ** successfully. An [error code] is returned otherwise.)^
6813: **
6814: ** ^Shared cache is disabled by default. It is recommended that it stay
6815: ** that way. In other words, do not use this routine. This interface
6816: ** continues to be provided for historical compatibility, but its use is
6817: ** discouraged. Any use of shared cache is discouraged. If shared cache
6818: ** must be used, it is recommended that shared cache only be enabled for
6819: ** individual database connections using the [sqlite3_open_v2()] interface
6820: ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6821: **
6822: ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6823: ** and will always return SQLITE_MISUSE. On those systems,
6824: ** shared cache mode should be enabled per-database connection via
6825: ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6826: **
6827: ** This interface is threadsafe on processors where writing a
6828: ** 32-bit integer is atomic.
6829: **
6830: ** See Also: [SQLite Shared-Cache Mode]
6831: */
6832: SQLITE_API int sqlite3_enable_shared_cache(int);
6833:
6834: /*
6835: ** CAPI3REF: Attempt To Free Heap Memory
6836: **
6837: ** ^The sqlite3_release_memory() interface attempts to free N bytes
6838: ** of heap memory by deallocating non-essential memory allocations
6839: ** held by the database library. Memory used to cache database
6840: ** pages to improve performance is an example of non-essential memory.
6841: ** ^sqlite3_release_memory() returns the number of bytes actually freed,
6842: ** which might be more or less than the amount requested.
6843: ** ^The sqlite3_release_memory() routine is a no-op returning zero
6844: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6845: **
6846: ** See also: [sqlite3_db_release_memory()]
6847: */
6848: SQLITE_API int sqlite3_release_memory(int);
6849:
6850: /*
6851: ** CAPI3REF: Free Memory Used By A Database Connection
6852: ** METHOD: sqlite3
6853: **
6854: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6855: ** memory as possible from database connection D. Unlike the
6856: ** [sqlite3_release_memory()] interface, this interface is in effect even
6857: ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6858: ** omitted.
6859: **
6860: ** See also: [sqlite3_release_memory()]
6861: */
6862: SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6863:
6864: /*
6865: ** CAPI3REF: Impose A Limit On Heap Size
6866: **
6867: ** These interfaces impose limits on the amount of heap memory that will be
6868: ** by all database connections within a single process.
6869: **
6870: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6871: ** soft limit on the amount of heap memory that may be allocated by SQLite.
6872: ** ^SQLite strives to keep heap memory utilization below the soft heap
6873: ** limit by reducing the number of pages held in the page cache
6874: ** as heap memory usages approaches the limit.
6875: ** ^The soft heap limit is "soft" because even though SQLite strives to stay
6876: ** below the limit, it will exceed the limit rather than generate
6877: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6878: ** is advisory only.
6879: **
6880: ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6881: ** N bytes on the amount of memory that will be allocated. ^The
6882: ** sqlite3_hard_heap_limit64(N) interface is similar to
6883: ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6884: ** when the hard heap limit is reached.
6885: **
6886: ** ^The return value from both sqlite3_soft_heap_limit64() and
6887: ** sqlite3_hard_heap_limit64() is the size of
6888: ** the heap limit prior to the call, or negative in the case of an
6889: ** error. ^If the argument N is negative
6890: ** then no change is made to the heap limit. Hence, the current
6891: ** size of heap limits can be determined by invoking
6892: ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6893: **
6894: ** ^Setting the heap limits to zero disables the heap limiter mechanism.
6895: **
6896: ** ^The soft heap limit may not be greater than the hard heap limit.
6897: ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6898: ** is invoked with a value of N that is greater than the hard heap limit,
6899: ** the soft heap limit is set to the value of the hard heap limit.
6900: ** ^The soft heap limit is automatically enabled whenever the hard heap
6901: ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6902: ** the soft heap limit is outside the range of 1..N, then the soft heap
6903: ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6904: ** hard heap limit is enabled makes the soft heap limit equal to the
6905: ** hard heap limit.
6906: **
6907: ** The memory allocation limits can also be adjusted using
6908: ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6909: **
6910: ** ^(The heap limits are not enforced in the current implementation
6911: ** if one or more of following conditions are true:
6912: **
6913: ** <ul>
6914: ** <li> The limit value is set to zero.
6915: ** <li> Memory accounting is disabled using a combination of the
6916: ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6917: ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6918: ** <li> An alternative page cache implementation is specified using
6919: ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6920: ** <li> The page cache allocates from its own memory pool supplied
6921: ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6922: ** from the heap.
6923: ** </ul>)^
6924: **
6925: ** The circumstances under which SQLite will enforce the heap limits may
6926: ** changes in future releases of SQLite.
6927: */
6928: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6929: SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6930:
6931: /*
6932: ** CAPI3REF: Deprecated Soft Heap Limit Interface
6933: ** DEPRECATED
6934: **
6935: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6936: ** interface. This routine is provided for historical compatibility
6937: ** only. All new applications should use the
6938: ** [sqlite3_soft_heap_limit64()] interface rather than this one.
6939: */
6940: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6941:
6942:
6943: /*
6944: ** CAPI3REF: Extract Metadata About A Column Of A Table
6945: ** METHOD: sqlite3
6946: **
6947: ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6948: ** information about column C of table T in database D
6949: ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6950: ** interface returns SQLITE_OK and fills in the non-NULL pointers in
6951: ** the final five arguments with appropriate values if the specified
6952: ** column exists. ^The sqlite3_table_column_metadata() interface returns
6953: ** SQLITE_ERROR if the specified column does not exist.
6954: ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6955: ** NULL pointer, then this routine simply checks for the existence of the
6956: ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6957: ** does not. If the table name parameter T in a call to
6958: ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6959: ** undefined behavior.
6960: **
6961: ** ^The column is identified by the second, third and fourth parameters to
6962: ** this function. ^(The second parameter is either the name of the database
6963: ** (i.e. "main", "temp", or an attached database) containing the specified
6964: ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6965: ** for the table using the same algorithm used by the database engine to
6966: ** resolve unqualified table references.
6967: **
6968: ** ^The third and fourth parameters to this function are the table and column
6969: ** name of the desired column, respectively.
6970: **
6971: ** ^Metadata is returned by writing to the memory locations passed as the 5th
6972: ** and subsequent parameters to this function. ^Any of these arguments may be
6973: ** NULL, in which case the corresponding element of metadata is omitted.
6974: **
6975: ** ^(<blockquote>
6976: ** <table border="1">
6977: ** <tr><th> Parameter <th> Output<br>Type <th> Description
6978: **
6979: ** <tr><td> 5th <td> const char* <td> Data type
6980: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6981: ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6982: ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6983: ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6984: ** </table>
6985: ** </blockquote>)^
6986: **
6987: ** ^The memory pointed to by the character pointers returned for the
6988: ** declaration type and collation sequence is valid until the next
6989: ** call to any SQLite API function.
6990: **
6991: ** ^If the specified table is actually a view, an [error code] is returned.
6992: **
6993: ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6994: ** is not a [WITHOUT ROWID] table and an
6995: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6996: ** parameters are set for the explicitly declared column. ^(If there is no
6997: ** [INTEGER PRIMARY KEY] column, then the outputs
6998: ** for the [rowid] are set as follows:
6999: **
7000: ** <pre>
7001: ** data type: "INTEGER"
7002: ** collation sequence: "BINARY"
7003: ** not null: 0
7004: ** primary key: 1
7005: ** auto increment: 0
7006: ** </pre>)^
7007: **
7008: ** ^This function causes all database schemas to be read from disk and
7009: ** parsed, if that has not already been done, and returns an error if
7010: ** any errors are encountered while loading the schema.
7011: */
7012: SQLITE_API int sqlite3_table_column_metadata(
7013: sqlite3 *db, /* Connection handle */
7014: const char *zDbName, /* Database name or NULL */
7015: const char *zTableName, /* Table name */
7016: const char *zColumnName, /* Column name */
7017: char const **pzDataType, /* OUTPUT: Declared data type */
7018: char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7019: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7020: int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7021: int *pAutoinc /* OUTPUT: True if column is auto-increment */
7022: );
7023:
7024: /*
7025: ** CAPI3REF: Load An Extension
7026: ** METHOD: sqlite3
7027: **
7028: ** ^This interface loads an SQLite extension library from the named file.
7029: **
7030: ** ^The sqlite3_load_extension() interface attempts to load an
7031: ** [SQLite extension] library contained in the file zFile. If
7032: ** the file cannot be loaded directly, attempts are made to load
7033: ** with various operating-system specific extensions added.
7034: ** So for example, if "samplelib" cannot be loaded, then names like
7035: ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7036: ** be tried also.
7037: **
7038: ** ^The entry point is zProc.
7039: ** ^(zProc may be 0, in which case SQLite will try to come up with an
7040: ** entry point name on its own. It first tries "sqlite3_extension_init".
7041: ** If that does not work, it constructs a name "sqlite3_X_init" where the
7042: ** X is consists of the lower-case equivalent of all ASCII alphabetic
7043: ** characters in the filename from the last "/" to the first following
7044: ** "." and omitting any initial "lib".)^
7045: ** ^The sqlite3_load_extension() interface returns
7046: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7047: ** ^If an error occurs and pzErrMsg is not 0, then the
7048: ** [sqlite3_load_extension()] interface shall attempt to
7049: ** fill *pzErrMsg with error message text stored in memory
7050: ** obtained from [sqlite3_malloc()]. The calling function
7051: ** should free this memory by calling [sqlite3_free()].
7052: **
7053: ** ^Extension loading must be enabled using
7054: ** [sqlite3_enable_load_extension()] or
7055: ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7056: ** prior to calling this API,
7057: ** otherwise an error will be returned.
7058: **
7059: ** <b>Security warning:</b> It is recommended that the
7060: ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7061: ** interface. The use of the [sqlite3_enable_load_extension()] interface
7062: ** should be avoided. This will keep the SQL function [load_extension()]
7063: ** disabled and prevent SQL injections from giving attackers
7064: ** access to extension loading capabilities.
7065: **
7066: ** See also the [load_extension() SQL function].
7067: */
7068: SQLITE_API int sqlite3_load_extension(
7069: sqlite3 *db, /* Load the extension into this database connection */
7070: const char *zFile, /* Name of the shared library containing extension */
7071: const char *zProc, /* Entry point. Derived from zFile if 0 */
7072: char **pzErrMsg /* Put error message here if not 0 */
7073: );
7074:
7075: /*
7076: ** CAPI3REF: Enable Or Disable Extension Loading
7077: ** METHOD: sqlite3
7078: **
7079: ** ^So as not to open security holes in older applications that are
7080: ** unprepared to deal with [extension loading], and as a means of disabling
7081: ** [extension loading] while evaluating user-entered SQL, the following API
7082: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7083: **
7084: ** ^Extension loading is off by default.
7085: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7086: ** to turn extension loading on and call it with onoff==0 to turn
7087: ** it back off again.
7088: **
7089: ** ^This interface enables or disables both the C-API
7090: ** [sqlite3_load_extension()] and the SQL function [load_extension()].
7091: ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7092: ** to enable or disable only the C-API.)^
7093: **
7094: ** <b>Security warning:</b> It is recommended that extension loading
7095: ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7096: ** rather than this interface, so the [load_extension()] SQL function
7097: ** remains disabled. This will prevent SQL injections from giving attackers
7098: ** access to extension loading capabilities.
7099: */
7100: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7101:
7102: /*
7103: ** CAPI3REF: Automatically Load Statically Linked Extensions
7104: **
7105: ** ^This interface causes the xEntryPoint() function to be invoked for
7106: ** each new [database connection] that is created. The idea here is that
7107: ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7108: ** that is to be automatically loaded into all new database connections.
7109: **
7110: ** ^(Even though the function prototype shows that xEntryPoint() takes
7111: ** no arguments and returns void, SQLite invokes xEntryPoint() with three
7112: ** arguments and expects an integer result as if the signature of the
7113: ** entry point where as follows:
7114: **
7115: ** <blockquote><pre>
7116: ** int xEntryPoint(
7117: ** sqlite3 *db,
7118: ** const char **pzErrMsg,
7119: ** const struct sqlite3_api_routines *pThunk
7120: ** );
7121: ** </pre></blockquote>)^
7122: **
7123: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7124: ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7125: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7126: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7127: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7128: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7129: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7130: **
7131: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7132: ** on the list of automatic extensions is a harmless no-op. ^No entry point
7133: ** will be called more than once for each database connection that is opened.
7134: **
7135: ** See also: [sqlite3_reset_auto_extension()]
7136: ** and [sqlite3_cancel_auto_extension()]
7137: */
7138: SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7139:
7140: /*
7141: ** CAPI3REF: Cancel Automatic Extension Loading
7142: **
7143: ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7144: ** initialization routine X that was registered using a prior call to
7145: ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7146: ** routine returns 1 if initialization routine X was successfully
7147: ** unregistered and it returns 0 if X was not on the list of initialization
7148: ** routines.
7149: */
7150: SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7151:
7152: /*
7153: ** CAPI3REF: Reset Automatic Extension Loading
7154: **
7155: ** ^This interface disables all automatic extensions previously
7156: ** registered using [sqlite3_auto_extension()].
7157: */
7158: SQLITE_API void sqlite3_reset_auto_extension(void);
7159:
7160: /*
7161: ** Structures used by the virtual table interface
7162: */
7163: typedef struct sqlite3_vtab sqlite3_vtab;
7164: typedef struct sqlite3_index_info sqlite3_index_info;
7165: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7166: typedef struct sqlite3_module sqlite3_module;
7167:
7168: /*
7169: ** CAPI3REF: Virtual Table Object
7170: ** KEYWORDS: sqlite3_module {virtual table module}
7171: **
7172: ** This structure, sometimes called a "virtual table module",
7173: ** defines the implementation of a [virtual table].
7174: ** This structure consists mostly of methods for the module.
7175: **
7176: ** ^A virtual table module is created by filling in a persistent
7177: ** instance of this structure and passing a pointer to that instance
7178: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7179: ** ^The registration remains valid until it is replaced by a different
7180: ** module or until the [database connection] closes. The content
7181: ** of this structure must not change while it is registered with
7182: ** any database connection.
7183: */
7184: struct sqlite3_module {
7185: int iVersion;
7186: int (*xCreate)(sqlite3*, void *pAux,
7187: int argc, const char *const*argv,
7188: sqlite3_vtab **ppVTab, char**);
7189: int (*xConnect)(sqlite3*, void *pAux,
7190: int argc, const char *const*argv,
7191: sqlite3_vtab **ppVTab, char**);
7192: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7193: int (*xDisconnect)(sqlite3_vtab *pVTab);
7194: int (*xDestroy)(sqlite3_vtab *pVTab);
7195: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7196: int (*xClose)(sqlite3_vtab_cursor*);
7197: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7198: int argc, sqlite3_value **argv);
7199: int (*xNext)(sqlite3_vtab_cursor*);
7200: int (*xEof)(sqlite3_vtab_cursor*);
7201: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7202: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7203: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7204: int (*xBegin)(sqlite3_vtab *pVTab);
7205: int (*xSync)(sqlite3_vtab *pVTab);
7206: int (*xCommit)(sqlite3_vtab *pVTab);
7207: int (*xRollback)(sqlite3_vtab *pVTab);
7208: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7209: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7210: void **ppArg);
7211: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7212: /* The methods above are in version 1 of the sqlite_module object. Those
7213: ** below are for version 2 and greater. */
7214: int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7215: int (*xRelease)(sqlite3_vtab *pVTab, int);
7216: int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7217: /* The methods above are in versions 1 and 2 of the sqlite_module object.
7218: ** Those below are for version 3 and greater. */
7219: int (*xShadowName)(const char*);
7220: };
7221:
7222: /*
7223: ** CAPI3REF: Virtual Table Indexing Information
7224: ** KEYWORDS: sqlite3_index_info
7225: **
7226: ** The sqlite3_index_info structure and its substructures is used as part
7227: ** of the [virtual table] interface to
7228: ** pass information into and receive the reply from the [xBestIndex]
7229: ** method of a [virtual table module]. The fields under **Inputs** are the
7230: ** inputs to xBestIndex and are read-only. xBestIndex inserts its
7231: ** results into the **Outputs** fields.
7232: **
7233: ** ^(The aConstraint[] array records WHERE clause constraints of the form:
7234: **
7235: ** <blockquote>column OP expr</blockquote>
7236: **
7237: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
7238: ** stored in aConstraint[].op using one of the
7239: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7240: ** ^(The index of the column is stored in
7241: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7242: ** expr on the right-hand side can be evaluated (and thus the constraint
7243: ** is usable) and false if it cannot.)^
7244: **
7245: ** ^The optimizer automatically inverts terms of the form "expr OP column"
7246: ** and makes other simplifications to the WHERE clause in an attempt to
7247: ** get as many WHERE clause terms into the form shown above as possible.
7248: ** ^The aConstraint[] array only reports WHERE clause terms that are
7249: ** relevant to the particular virtual table being queried.
7250: **
7251: ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7252: ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7253: **
7254: ** The colUsed field indicates which columns of the virtual table may be
7255: ** required by the current scan. Virtual table columns are numbered from
7256: ** zero in the order in which they appear within the CREATE TABLE statement
7257: ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7258: ** the corresponding bit is set within the colUsed mask if the column may be
7259: ** required by SQLite. If the table has at least 64 columns and any column
7260: ** to the right of the first 63 is required, then bit 63 of colUsed is also
7261: ** set. In other words, column iCol may be required if the expression
7262: ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7263: ** non-zero.
7264: **
7265: ** The [xBestIndex] method must fill aConstraintUsage[] with information
7266: ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7267: ** the right-hand side of the corresponding aConstraint[] is evaluated
7268: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7269: ** is true, then the constraint is assumed to be fully handled by the
7270: ** virtual table and might not be checked again by the byte code.)^ ^(The
7271: ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7272: ** is left in its default setting of false, the constraint will always be
7273: ** checked separately in byte code. If the omit flag is change to true, then
7274: ** the constraint may or may not be checked in byte code. In other words,
7275: ** when the omit flag is true there is no guarantee that the constraint will
7276: ** not be checked again using byte code.)^
7277: **
7278: ** ^The idxNum and idxStr values are recorded and passed into the
7279: ** [xFilter] method.
7280: ** ^[sqlite3_free()] is used to free idxStr if and only if
7281: ** needToFreeIdxStr is true.
7282: **
7283: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7284: ** the correct order to satisfy the ORDER BY clause so that no separate
7285: ** sorting step is required.
7286: **
7287: ** ^The estimatedCost value is an estimate of the cost of a particular
7288: ** strategy. A cost of N indicates that the cost of the strategy is similar
7289: ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7290: ** indicates that the expense of the operation is similar to that of a
7291: ** binary search on a unique indexed field of an SQLite table with N rows.
7292: **
7293: ** ^The estimatedRows value is an estimate of the number of rows that
7294: ** will be returned by the strategy.
7295: **
7296: ** The xBestIndex method may optionally populate the idxFlags field with a
7297: ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7298: ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7299: ** assumes that the strategy may visit at most one row.
7300: **
7301: ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7302: ** SQLite also assumes that if a call to the xUpdate() method is made as
7303: ** part of the same statement to delete or update a virtual table row and the
7304: ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7305: ** any database changes. In other words, if the xUpdate() returns
7306: ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7307: ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7308: ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7309: ** the xUpdate method are automatically rolled back by SQLite.
7310: **
7311: ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7312: ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7313: ** If a virtual table extension is
7314: ** used with an SQLite version earlier than 3.8.2, the results of attempting
7315: ** to read or write the estimatedRows field are undefined (but are likely
7316: ** to include crashing the application). The estimatedRows field should
7317: ** therefore only be used if [sqlite3_libversion_number()] returns a
7318: ** value greater than or equal to 3008002. Similarly, the idxFlags field
7319: ** was added for [version 3.9.0] ([dateof:3.9.0]).
7320: ** It may therefore only be used if
7321: ** sqlite3_libversion_number() returns a value greater than or equal to
7322: ** 3009000.
7323: */
7324: struct sqlite3_index_info {
7325: /* Inputs */
7326: int nConstraint; /* Number of entries in aConstraint */
7327: struct sqlite3_index_constraint {
7328: int iColumn; /* Column constrained. -1 for ROWID */
7329: unsigned char op; /* Constraint operator */
7330: unsigned char usable; /* True if this constraint is usable */
7331: int iTermOffset; /* Used internally - xBestIndex should ignore */
7332: } *aConstraint; /* Table of WHERE clause constraints */
7333: int nOrderBy; /* Number of terms in the ORDER BY clause */
7334: struct sqlite3_index_orderby {
7335: int iColumn; /* Column number */
7336: unsigned char desc; /* True for DESC. False for ASC. */
7337: } *aOrderBy; /* The ORDER BY clause */
7338: /* Outputs */
7339: struct sqlite3_index_constraint_usage {
7340: int argvIndex; /* if >0, constraint is part of argv to xFilter */
7341: unsigned char omit; /* Do not code a test for this constraint */
7342: } *aConstraintUsage;
7343: int idxNum; /* Number used to identify the index */
7344: char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7345: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7346: int orderByConsumed; /* True if output is already ordered */
7347: double estimatedCost; /* Estimated cost of using this index */
7348: /* Fields below are only available in SQLite 3.8.2 and later */
7349: sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7350: /* Fields below are only available in SQLite 3.9.0 and later */
7351: int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7352: /* Fields below are only available in SQLite 3.10.0 and later */
7353: sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7354: };
7355:
7356: /*
7357: ** CAPI3REF: Virtual Table Scan Flags
7358: **
7359: ** Virtual table implementations are allowed to set the
7360: ** [sqlite3_index_info].idxFlags field to some combination of
7361: ** these bits.
7362: */
7363: #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7364:
7365: /*
7366: ** CAPI3REF: Virtual Table Constraint Operator Codes
7367: **
7368: ** These macros define the allowed values for the
7369: ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7370: ** an operator that is part of a constraint term in the WHERE clause of
7371: ** a query that uses a [virtual table].
7372: **
7373: ** ^The left-hand operand of the operator is given by the corresponding
7374: ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7375: ** operand is the rowid.
7376: ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7377: ** operators have no left-hand operand, and so for those operators the
7378: ** corresponding aConstraint[].iColumn is meaningless and should not be
7379: ** used.
7380: **
7381: ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7382: ** value 255 are reserved to represent functions that are overloaded
7383: ** by the [xFindFunction|xFindFunction method] of the virtual table
7384: ** implementation.
7385: **
7386: ** The right-hand operands for each constraint might be accessible using
7387: ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7388: ** operand is only available if it appears as a single constant literal
7389: ** in the input SQL. If the right-hand operand is another column or an
7390: ** expression (even a constant expression) or a parameter, then the
7391: ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7392: ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7393: ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7394: ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7395: ** always return SQLITE_NOTFOUND.
7396: **
7397: ** The collating sequence to be used for comparison can be found using
7398: ** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7399: ** tables, the collating sequence of constraints does not matter (for example
7400: ** because the constraints are numeric) and so the sqlite3_vtab_collation()
7401: ** interface is not commonly needed.
7402: */
7403: #define SQLITE_INDEX_CONSTRAINT_EQ 2
7404: #define SQLITE_INDEX_CONSTRAINT_GT 4
7405: #define SQLITE_INDEX_CONSTRAINT_LE 8
7406: #define SQLITE_INDEX_CONSTRAINT_LT 16
7407: #define SQLITE_INDEX_CONSTRAINT_GE 32
7408: #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7409: #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7410: #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7411: #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7412: #define SQLITE_INDEX_CONSTRAINT_NE 68
7413: #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7414: #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7415: #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7416: #define SQLITE_INDEX_CONSTRAINT_IS 72
7417: #define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7418: #define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7419: #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7420:
7421: /*
7422: ** CAPI3REF: Register A Virtual Table Implementation
7423: ** METHOD: sqlite3
7424: **
7425: ** ^These routines are used to register a new [virtual table module] name.
7426: ** ^Module names must be registered before
7427: ** creating a new [virtual table] using the module and before using a
7428: ** preexisting [virtual table] for the module.
7429: **
7430: ** ^The module name is registered on the [database connection] specified
7431: ** by the first parameter. ^The name of the module is given by the
7432: ** second parameter. ^The third parameter is a pointer to
7433: ** the implementation of the [virtual table module]. ^The fourth
7434: ** parameter is an arbitrary client data pointer that is passed through
7435: ** into the [xCreate] and [xConnect] methods of the virtual table module
7436: ** when a new virtual table is be being created or reinitialized.
7437: **
7438: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7439: ** is a pointer to a destructor for the pClientData. ^SQLite will
7440: ** invoke the destructor function (if it is not NULL) when SQLite
7441: ** no longer needs the pClientData pointer. ^The destructor will also
7442: ** be invoked if the call to sqlite3_create_module_v2() fails.
7443: ** ^The sqlite3_create_module()
7444: ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7445: ** destructor.
7446: **
7447: ** ^If the third parameter (the pointer to the sqlite3_module object) is
7448: ** NULL then no new module is created and any existing modules with the
7449: ** same name are dropped.
7450: **
7451: ** See also: [sqlite3_drop_modules()]
7452: */
7453: SQLITE_API int sqlite3_create_module(
7454: sqlite3 *db, /* SQLite connection to register module with */
7455: const char *zName, /* Name of the module */
7456: const sqlite3_module *p, /* Methods for the module */
7457: void *pClientData /* Client data for xCreate/xConnect */
7458: );
7459: SQLITE_API int sqlite3_create_module_v2(
7460: sqlite3 *db, /* SQLite connection to register module with */
7461: const char *zName, /* Name of the module */
7462: const sqlite3_module *p, /* Methods for the module */
7463: void *pClientData, /* Client data for xCreate/xConnect */
7464: void(*xDestroy)(void*) /* Module destructor function */
7465: );
7466:
7467: /*
7468: ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7469: ** METHOD: sqlite3
7470: **
7471: ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7472: ** table modules from database connection D except those named on list L.
7473: ** The L parameter must be either NULL or a pointer to an array of pointers
7474: ** to strings where the array is terminated by a single NULL pointer.
7475: ** ^If the L parameter is NULL, then all virtual table modules are removed.
7476: **
7477: ** See also: [sqlite3_create_module()]
7478: */
7479: SQLITE_API int sqlite3_drop_modules(
7480: sqlite3 *db, /* Remove modules from this connection */
7481: const char **azKeep /* Except, do not remove the ones named here */
7482: );
7483:
7484: /*
7485: ** CAPI3REF: Virtual Table Instance Object
7486: ** KEYWORDS: sqlite3_vtab
7487: **
7488: ** Every [virtual table module] implementation uses a subclass
7489: ** of this object to describe a particular instance
7490: ** of the [virtual table]. Each subclass will
7491: ** be tailored to the specific needs of the module implementation.
7492: ** The purpose of this superclass is to define certain fields that are
7493: ** common to all module implementations.
7494: **
7495: ** ^Virtual tables methods can set an error message by assigning a
7496: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7497: ** take care that any prior string is freed by a call to [sqlite3_free()]
7498: ** prior to assigning a new string to zErrMsg. ^After the error message
7499: ** is delivered up to the client application, the string will be automatically
7500: ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7501: */
7502: struct sqlite3_vtab {
7503: const sqlite3_module *pModule; /* The module for this virtual table */
7504: int nRef; /* Number of open cursors */
7505: char *zErrMsg; /* Error message from sqlite3_mprintf() */
7506: /* Virtual table implementations will typically add additional fields */
7507: };
7508:
7509: /*
7510: ** CAPI3REF: Virtual Table Cursor Object
7511: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7512: **
7513: ** Every [virtual table module] implementation uses a subclass of the
7514: ** following structure to describe cursors that point into the
7515: ** [virtual table] and are used
7516: ** to loop through the virtual table. Cursors are created using the
7517: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7518: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7519: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7520: ** of the module. Each module implementation will define
7521: ** the content of a cursor structure to suit its own needs.
7522: **
7523: ** This superclass exists in order to define fields of the cursor that
7524: ** are common to all implementations.
7525: */
7526: struct sqlite3_vtab_cursor {
7527: sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7528: /* Virtual table implementations will typically add additional fields */
7529: };
7530:
7531: /*
7532: ** CAPI3REF: Declare The Schema Of A Virtual Table
7533: **
7534: ** ^The [xCreate] and [xConnect] methods of a
7535: ** [virtual table module] call this interface
7536: ** to declare the format (the names and datatypes of the columns) of
7537: ** the virtual tables they implement.
7538: */
7539: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7540:
7541: /*
7542: ** CAPI3REF: Overload A Function For A Virtual Table
7543: ** METHOD: sqlite3
7544: **
7545: ** ^(Virtual tables can provide alternative implementations of functions
7546: ** using the [xFindFunction] method of the [virtual table module].
7547: ** But global versions of those functions
7548: ** must exist in order to be overloaded.)^
7549: **
7550: ** ^(This API makes sure a global version of a function with a particular
7551: ** name and number of parameters exists. If no such function exists
7552: ** before this API is called, a new function is created.)^ ^The implementation
7553: ** of the new function always causes an exception to be thrown. So
7554: ** the new function is not good for anything by itself. Its only
7555: ** purpose is to be a placeholder function that can be overloaded
7556: ** by a [virtual table].
7557: */
7558: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7559:
7560: /*
7561: ** CAPI3REF: A Handle To An Open BLOB
7562: ** KEYWORDS: {BLOB handle} {BLOB handles}
7563: **
7564: ** An instance of this object represents an open BLOB on which
7565: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7566: ** ^Objects of this type are created by [sqlite3_blob_open()]
7567: ** and destroyed by [sqlite3_blob_close()].
7568: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7569: ** can be used to read or write small subsections of the BLOB.
7570: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7571: */
7572: typedef struct sqlite3_blob sqlite3_blob;
7573:
7574: /*
7575: ** CAPI3REF: Open A BLOB For Incremental I/O
7576: ** METHOD: sqlite3
7577: ** CONSTRUCTOR: sqlite3_blob
7578: **
7579: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7580: ** in row iRow, column zColumn, table zTable in database zDb;
7581: ** in other words, the same BLOB that would be selected by:
7582: **
7583: ** <pre>
7584: ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7585: ** </pre>)^
7586: **
7587: ** ^(Parameter zDb is not the filename that contains the database, but
7588: ** rather the symbolic name of the database. For attached databases, this is
7589: ** the name that appears after the AS keyword in the [ATTACH] statement.
7590: ** For the main database file, the database name is "main". For TEMP
7591: ** tables, the database name is "temp".)^
7592: **
7593: ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7594: ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7595: ** read-only access.
7596: **
7597: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7598: ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7599: ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7600: ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7601: ** on *ppBlob after this function it returns.
7602: **
7603: ** This function fails with SQLITE_ERROR if any of the following are true:
7604: ** <ul>
7605: ** <li> ^(Database zDb does not exist)^,
7606: ** <li> ^(Table zTable does not exist within database zDb)^,
7607: ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7608: ** <li> ^(Column zColumn does not exist)^,
7609: ** <li> ^(Row iRow is not present in the table)^,
7610: ** <li> ^(The specified column of row iRow contains a value that is not
7611: ** a TEXT or BLOB value)^,
7612: ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7613: ** constraint and the blob is being opened for read/write access)^,
7614: ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7615: ** column zColumn is part of a [child key] definition and the blob is
7616: ** being opened for read/write access)^.
7617: ** </ul>
7618: **
7619: ** ^Unless it returns SQLITE_MISUSE, this function sets the
7620: ** [database connection] error code and message accessible via
7621: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7622: **
7623: ** A BLOB referenced by sqlite3_blob_open() may be read using the
7624: ** [sqlite3_blob_read()] interface and modified by using
7625: ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7626: ** different row of the same table using the [sqlite3_blob_reopen()]
7627: ** interface. However, the column, table, or database of a [BLOB handle]
7628: ** cannot be changed after the [BLOB handle] is opened.
7629: **
7630: ** ^(If the row that a BLOB handle points to is modified by an
7631: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7632: ** then the BLOB handle is marked as "expired".
7633: ** This is true if any column of the row is changed, even a column
7634: ** other than the one the BLOB handle is open on.)^
7635: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7636: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7637: ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7638: ** rolled back by the expiration of the BLOB. Such changes will eventually
7639: ** commit if the transaction continues to completion.)^
7640: **
7641: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7642: ** the opened blob. ^The size of a blob may not be changed by this
7643: ** interface. Use the [UPDATE] SQL command to change the size of a
7644: ** blob.
7645: **
7646: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7647: ** and the built-in [zeroblob] SQL function may be used to create a
7648: ** zero-filled blob to read or write using the incremental-blob interface.
7649: **
7650: ** To avoid a resource leak, every open [BLOB handle] should eventually
7651: ** be released by a call to [sqlite3_blob_close()].
7652: **
7653: ** See also: [sqlite3_blob_close()],
7654: ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7655: ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7656: */
7657: SQLITE_API int sqlite3_blob_open(
7658: sqlite3*,
7659: const char *zDb,
7660: const char *zTable,
7661: const char *zColumn,
7662: sqlite3_int64 iRow,
7663: int flags,
7664: sqlite3_blob **ppBlob
7665: );
7666:
7667: /*
7668: ** CAPI3REF: Move a BLOB Handle to a New Row
7669: ** METHOD: sqlite3_blob
7670: **
7671: ** ^This function is used to move an existing [BLOB handle] so that it points
7672: ** to a different row of the same database table. ^The new row is identified
7673: ** by the rowid value passed as the second argument. Only the row can be
7674: ** changed. ^The database, table and column on which the blob handle is open
7675: ** remain the same. Moving an existing [BLOB handle] to a new row is
7676: ** faster than closing the existing handle and opening a new one.
7677: **
7678: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7679: ** it must exist and there must be either a blob or text value stored in
7680: ** the nominated column.)^ ^If the new row is not present in the table, or if
7681: ** it does not contain a blob or text value, or if another error occurs, an
7682: ** SQLite error code is returned and the blob handle is considered aborted.
7683: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7684: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7685: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7686: ** always returns zero.
7687: **
7688: ** ^This function sets the database handle error code and message.
7689: */
7690: SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7691:
7692: /*
7693: ** CAPI3REF: Close A BLOB Handle
7694: ** DESTRUCTOR: sqlite3_blob
7695: **
7696: ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7697: ** unconditionally. Even if this routine returns an error code, the
7698: ** handle is still closed.)^
7699: **
7700: ** ^If the blob handle being closed was opened for read-write access, and if
7701: ** the database is in auto-commit mode and there are no other open read-write
7702: ** blob handles or active write statements, the current transaction is
7703: ** committed. ^If an error occurs while committing the transaction, an error
7704: ** code is returned and the transaction rolled back.
7705: **
7706: ** Calling this function with an argument that is not a NULL pointer or an
7707: ** open blob handle results in undefined behaviour. ^Calling this routine
7708: ** with a null pointer (such as would be returned by a failed call to
7709: ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7710: ** is passed a valid open blob handle, the values returned by the
7711: ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7712: */
7713: SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7714:
7715: /*
7716: ** CAPI3REF: Return The Size Of An Open BLOB
7717: ** METHOD: sqlite3_blob
7718: **
7719: ** ^Returns the size in bytes of the BLOB accessible via the
7720: ** successfully opened [BLOB handle] in its only argument. ^The
7721: ** incremental blob I/O routines can only read or overwriting existing
7722: ** blob content; they cannot change the size of a blob.
7723: **
7724: ** This routine only works on a [BLOB handle] which has been created
7725: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7726: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7727: ** to this routine results in undefined and probably undesirable behavior.
7728: */
7729: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7730:
7731: /*
7732: ** CAPI3REF: Read Data From A BLOB Incrementally
7733: ** METHOD: sqlite3_blob
7734: **
7735: ** ^(This function is used to read data from an open [BLOB handle] into a
7736: ** caller-supplied buffer. N bytes of data are copied into buffer Z
7737: ** from the open BLOB, starting at offset iOffset.)^
7738: **
7739: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7740: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7741: ** less than zero, [SQLITE_ERROR] is returned and no data is read.
7742: ** ^The size of the blob (and hence the maximum value of N+iOffset)
7743: ** can be determined using the [sqlite3_blob_bytes()] interface.
7744: **
7745: ** ^An attempt to read from an expired [BLOB handle] fails with an
7746: ** error code of [SQLITE_ABORT].
7747: **
7748: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7749: ** Otherwise, an [error code] or an [extended error code] is returned.)^
7750: **
7751: ** This routine only works on a [BLOB handle] which has been created
7752: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7753: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7754: ** to this routine results in undefined and probably undesirable behavior.
7755: **
7756: ** See also: [sqlite3_blob_write()].
7757: */
7758: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7759:
7760: /*
7761: ** CAPI3REF: Write Data Into A BLOB Incrementally
7762: ** METHOD: sqlite3_blob
7763: **
7764: ** ^(This function is used to write data into an open [BLOB handle] from a
7765: ** caller-supplied buffer. N bytes of data are copied from the buffer Z
7766: ** into the open BLOB, starting at offset iOffset.)^
7767: **
7768: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7769: ** Otherwise, an [error code] or an [extended error code] is returned.)^
7770: ** ^Unless SQLITE_MISUSE is returned, this function sets the
7771: ** [database connection] error code and message accessible via
7772: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7773: **
7774: ** ^If the [BLOB handle] passed as the first argument was not opened for
7775: ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7776: ** this function returns [SQLITE_READONLY].
7777: **
7778: ** This function may only modify the contents of the BLOB; it is
7779: ** not possible to increase the size of a BLOB using this API.
7780: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7781: ** [SQLITE_ERROR] is returned and no data is written. The size of the
7782: ** BLOB (and hence the maximum value of N+iOffset) can be determined
7783: ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7784: ** than zero [SQLITE_ERROR] is returned and no data is written.
7785: **
7786: ** ^An attempt to write to an expired [BLOB handle] fails with an
7787: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7788: ** before the [BLOB handle] expired are not rolled back by the
7789: ** expiration of the handle, though of course those changes might
7790: ** have been overwritten by the statement that expired the BLOB handle
7791: ** or by other independent statements.
7792: **
7793: ** This routine only works on a [BLOB handle] which has been created
7794: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7795: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7796: ** to this routine results in undefined and probably undesirable behavior.
7797: **
7798: ** See also: [sqlite3_blob_read()].
7799: */
7800: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7801:
7802: /*
7803: ** CAPI3REF: Virtual File System Objects
7804: **
7805: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7806: ** that SQLite uses to interact
7807: ** with the underlying operating system. Most SQLite builds come with a
7808: ** single default VFS that is appropriate for the host computer.
7809: ** New VFSes can be registered and existing VFSes can be unregistered.
7810: ** The following interfaces are provided.
7811: **
7812: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7813: ** ^Names are case sensitive.
7814: ** ^Names are zero-terminated UTF-8 strings.
7815: ** ^If there is no match, a NULL pointer is returned.
7816: ** ^If zVfsName is NULL then the default VFS is returned.
7817: **
7818: ** ^New VFSes are registered with sqlite3_vfs_register().
7819: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7820: ** ^The same VFS can be registered multiple times without injury.
7821: ** ^To make an existing VFS into the default VFS, register it again
7822: ** with the makeDflt flag set. If two different VFSes with the
7823: ** same name are registered, the behavior is undefined. If a
7824: ** VFS is registered with a name that is NULL or an empty string,
7825: ** then the behavior is undefined.
7826: **
7827: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7828: ** ^(If the default VFS is unregistered, another VFS is chosen as
7829: ** the default. The choice for the new VFS is arbitrary.)^
7830: */
7831: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7832: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7833: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7834:
7835: /*
7836: ** CAPI3REF: Mutexes
7837: **
7838: ** The SQLite core uses these routines for thread
7839: ** synchronization. Though they are intended for internal
7840: ** use by SQLite, code that links against SQLite is
7841: ** permitted to use any of these routines.
7842: **
7843: ** The SQLite source code contains multiple implementations
7844: ** of these mutex routines. An appropriate implementation
7845: ** is selected automatically at compile-time. The following
7846: ** implementations are available in the SQLite core:
7847: **
7848: ** <ul>
7849: ** <li> SQLITE_MUTEX_PTHREADS
7850: ** <li> SQLITE_MUTEX_W32
7851: ** <li> SQLITE_MUTEX_NOOP
7852: ** </ul>
7853: **
7854: ** The SQLITE_MUTEX_NOOP implementation is a set of routines
7855: ** that does no real locking and is appropriate for use in
7856: ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7857: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7858: ** and Windows.
7859: **
7860: ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7861: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7862: ** implementation is included with the library. In this case the
7863: ** application must supply a custom mutex implementation using the
7864: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7865: ** before calling sqlite3_initialize() or any other public sqlite3_
7866: ** function that calls sqlite3_initialize().
7867: **
7868: ** ^The sqlite3_mutex_alloc() routine allocates a new
7869: ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7870: ** routine returns NULL if it is unable to allocate the requested
7871: ** mutex. The argument to sqlite3_mutex_alloc() must one of these
7872: ** integer constants:
7873: **
7874: ** <ul>
7875: ** <li> SQLITE_MUTEX_FAST
7876: ** <li> SQLITE_MUTEX_RECURSIVE
7877: ** <li> SQLITE_MUTEX_STATIC_MAIN
7878: ** <li> SQLITE_MUTEX_STATIC_MEM
7879: ** <li> SQLITE_MUTEX_STATIC_OPEN
7880: ** <li> SQLITE_MUTEX_STATIC_PRNG
7881: ** <li> SQLITE_MUTEX_STATIC_LRU
7882: ** <li> SQLITE_MUTEX_STATIC_PMEM
7883: ** <li> SQLITE_MUTEX_STATIC_APP1
7884: ** <li> SQLITE_MUTEX_STATIC_APP2
7885: ** <li> SQLITE_MUTEX_STATIC_APP3
7886: ** <li> SQLITE_MUTEX_STATIC_VFS1
7887: ** <li> SQLITE_MUTEX_STATIC_VFS2
7888: ** <li> SQLITE_MUTEX_STATIC_VFS3
7889: ** </ul>
7890: **
7891: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7892: ** cause sqlite3_mutex_alloc() to create
7893: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7894: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7895: ** The mutex implementation does not need to make a distinction
7896: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7897: ** not want to. SQLite will only request a recursive mutex in
7898: ** cases where it really needs one. If a faster non-recursive mutex
7899: ** implementation is available on the host platform, the mutex subsystem
7900: ** might return such a mutex in response to SQLITE_MUTEX_FAST.
7901: **
7902: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7903: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7904: ** a pointer to a static preexisting mutex. ^Nine static mutexes are
7905: ** used by the current version of SQLite. Future versions of SQLite
7906: ** may add additional static mutexes. Static mutexes are for internal
7907: ** use by SQLite only. Applications that use SQLite mutexes should
7908: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7909: ** SQLITE_MUTEX_RECURSIVE.
7910: **
7911: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7912: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7913: ** returns a different mutex on every call. ^For the static
7914: ** mutex types, the same mutex is returned on every call that has
7915: ** the same type number.
7916: **
7917: ** ^The sqlite3_mutex_free() routine deallocates a previously
7918: ** allocated dynamic mutex. Attempting to deallocate a static
7919: ** mutex results in undefined behavior.
7920: **
7921: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7922: ** to enter a mutex. ^If another thread is already within the mutex,
7923: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7924: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7925: ** upon successful entry. ^(Mutexes created using
7926: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7927: ** In such cases, the
7928: ** mutex must be exited an equal number of times before another thread
7929: ** can enter.)^ If the same thread tries to enter any mutex other
7930: ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7931: **
7932: ** ^(Some systems (for example, Windows 95) do not support the operation
7933: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7934: ** will always return SQLITE_BUSY. The SQLite core only ever uses
7935: ** sqlite3_mutex_try() as an optimization so this is acceptable
7936: ** behavior.)^
7937: **
7938: ** ^The sqlite3_mutex_leave() routine exits a mutex that was
7939: ** previously entered by the same thread. The behavior
7940: ** is undefined if the mutex is not currently entered by the
7941: ** calling thread or is not currently allocated.
7942: **
7943: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
7944: ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
7945: ** then any of the four routines behaves as a no-op.
7946: **
7947: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7948: */
7949: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7950: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7951: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7952: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7953: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7954:
7955: /*
7956: ** CAPI3REF: Mutex Methods Object
7957: **
7958: ** An instance of this structure defines the low-level routines
7959: ** used to allocate and use mutexes.
7960: **
7961: ** Usually, the default mutex implementations provided by SQLite are
7962: ** sufficient, however the application has the option of substituting a custom
7963: ** implementation for specialized deployments or systems for which SQLite
7964: ** does not provide a suitable implementation. In this case, the application
7965: ** creates and populates an instance of this structure to pass
7966: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7967: ** Additionally, an instance of this structure can be used as an
7968: ** output variable when querying the system for the current mutex
7969: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7970: **
7971: ** ^The xMutexInit method defined by this structure is invoked as
7972: ** part of system initialization by the sqlite3_initialize() function.
7973: ** ^The xMutexInit routine is called by SQLite exactly once for each
7974: ** effective call to [sqlite3_initialize()].
7975: **
7976: ** ^The xMutexEnd method defined by this structure is invoked as
7977: ** part of system shutdown by the sqlite3_shutdown() function. The
7978: ** implementation of this method is expected to release all outstanding
7979: ** resources obtained by the mutex methods implementation, especially
7980: ** those obtained by the xMutexInit method. ^The xMutexEnd()
7981: ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7982: **
7983: ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7984: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7985: ** xMutexNotheld) implement the following interfaces (respectively):
7986: **
7987: ** <ul>
7988: ** <li> [sqlite3_mutex_alloc()] </li>
7989: ** <li> [sqlite3_mutex_free()] </li>
7990: ** <li> [sqlite3_mutex_enter()] </li>
7991: ** <li> [sqlite3_mutex_try()] </li>
7992: ** <li> [sqlite3_mutex_leave()] </li>
7993: ** <li> [sqlite3_mutex_held()] </li>
7994: ** <li> [sqlite3_mutex_notheld()] </li>
7995: ** </ul>)^
7996: **
7997: ** The only difference is that the public sqlite3_XXX functions enumerated
7998: ** above silently ignore any invocations that pass a NULL pointer instead
7999: ** of a valid mutex handle. The implementations of the methods defined
8000: ** by this structure are not required to handle this case. The results
8001: ** of passing a NULL pointer instead of a valid mutex handle are undefined
8002: ** (i.e. it is acceptable to provide an implementation that segfaults if
8003: ** it is passed a NULL pointer).
8004: **
8005: ** The xMutexInit() method must be threadsafe. It must be harmless to
8006: ** invoke xMutexInit() multiple times within the same process and without
8007: ** intervening calls to xMutexEnd(). Second and subsequent calls to
8008: ** xMutexInit() must be no-ops.
8009: **
8010: ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8011: ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8012: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8013: ** memory allocation for a fast or recursive mutex.
8014: **
8015: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8016: ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8017: ** If xMutexInit fails in any way, it is expected to clean up after itself
8018: ** prior to returning.
8019: */
8020: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8021: struct sqlite3_mutex_methods {
8022: int (*xMutexInit)(void);
8023: int (*xMutexEnd)(void);
8024: sqlite3_mutex *(*xMutexAlloc)(int);
8025: void (*xMutexFree)(sqlite3_mutex *);
8026: void (*xMutexEnter)(sqlite3_mutex *);
8027: int (*xMutexTry)(sqlite3_mutex *);
8028: void (*xMutexLeave)(sqlite3_mutex *);
8029: int (*xMutexHeld)(sqlite3_mutex *);
8030: int (*xMutexNotheld)(sqlite3_mutex *);
8031: };
8032:
8033: /*
8034: ** CAPI3REF: Mutex Verification Routines
8035: **
8036: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8037: ** are intended for use inside assert() statements. The SQLite core
8038: ** never uses these routines except inside an assert() and applications
8039: ** are advised to follow the lead of the core. The SQLite core only
8040: ** provides implementations for these routines when it is compiled
8041: ** with the SQLITE_DEBUG flag. External mutex implementations
8042: ** are only required to provide these routines if SQLITE_DEBUG is
8043: ** defined and if NDEBUG is not defined.
8044: **
8045: ** These routines should return true if the mutex in their argument
8046: ** is held or not held, respectively, by the calling thread.
8047: **
8048: ** The implementation is not required to provide versions of these
8049: ** routines that actually work. If the implementation does not provide working
8050: ** versions of these routines, it should at least provide stubs that always
8051: ** return true so that one does not get spurious assertion failures.
8052: **
8053: ** If the argument to sqlite3_mutex_held() is a NULL pointer then
8054: ** the routine should return 1. This seems counter-intuitive since
8055: ** clearly the mutex cannot be held if it does not exist. But
8056: ** the reason the mutex does not exist is because the build is not
8057: ** using mutexes. And we do not want the assert() containing the
8058: ** call to sqlite3_mutex_held() to fail, so a non-zero return is
8059: ** the appropriate thing to do. The sqlite3_mutex_notheld()
8060: ** interface should also return 1 when given a NULL pointer.
8061: */
8062: #ifndef NDEBUG
8063: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8064: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8065: #endif
8066:
8067: /*
8068: ** CAPI3REF: Mutex Types
8069: **
8070: ** The [sqlite3_mutex_alloc()] interface takes a single argument
8071: ** which is one of these integer constants.
8072: **
8073: ** The set of static mutexes may change from one SQLite release to the
8074: ** next. Applications that override the built-in mutex logic must be
8075: ** prepared to accommodate additional static mutexes.
8076: */
8077: #define SQLITE_MUTEX_FAST 0
8078: #define SQLITE_MUTEX_RECURSIVE 1
8079: #define SQLITE_MUTEX_STATIC_MAIN 2
8080: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8081: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8082: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8083: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8084: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8085: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8086: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8087: #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8088: #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8089: #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8090: #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8091: #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8092: #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8093:
8094: /* Legacy compatibility: */
8095: #define SQLITE_MUTEX_STATIC_MASTER 2
8096:
8097:
8098: /*
8099: ** CAPI3REF: Retrieve the mutex for a database connection
8100: ** METHOD: sqlite3
8101: **
8102: ** ^This interface returns a pointer the [sqlite3_mutex] object that
8103: ** serializes access to the [database connection] given in the argument
8104: ** when the [threading mode] is Serialized.
8105: ** ^If the [threading mode] is Single-thread or Multi-thread then this
8106: ** routine returns a NULL pointer.
8107: */
8108: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8109:
8110: /*
8111: ** CAPI3REF: Low-Level Control Of Database Files
8112: ** METHOD: sqlite3
8113: ** KEYWORDS: {file control}
8114: **
8115: ** ^The [sqlite3_file_control()] interface makes a direct call to the
8116: ** xFileControl method for the [sqlite3_io_methods] object associated
8117: ** with a particular database identified by the second argument. ^The
8118: ** name of the database is "main" for the main database or "temp" for the
8119: ** TEMP database, or the name that appears after the AS keyword for
8120: ** databases that are added using the [ATTACH] SQL command.
8121: ** ^A NULL pointer can be used in place of "main" to refer to the
8122: ** main database file.
8123: ** ^The third and fourth parameters to this routine
8124: ** are passed directly through to the second and third parameters of
8125: ** the xFileControl method. ^The return value of the xFileControl
8126: ** method becomes the return value of this routine.
8127: **
8128: ** A few opcodes for [sqlite3_file_control()] are handled directly
8129: ** by the SQLite core and never invoke the
8130: ** sqlite3_io_methods.xFileControl method.
8131: ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8132: ** a pointer to the underlying [sqlite3_file] object to be written into
8133: ** the space pointed to by the 4th parameter. The
8134: ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8135: ** the [sqlite3_file] object associated with the journal file instead of
8136: ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8137: ** a pointer to the underlying [sqlite3_vfs] object for the file.
8138: ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8139: ** from the pager.
8140: **
8141: ** ^If the second parameter (zDbName) does not match the name of any
8142: ** open database file, then SQLITE_ERROR is returned. ^This error
8143: ** code is not remembered and will not be recalled by [sqlite3_errcode()]
8144: ** or [sqlite3_errmsg()]. The underlying xFileControl method might
8145: ** also return SQLITE_ERROR. There is no way to distinguish between
8146: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8147: ** xFileControl method.
8148: **
8149: ** See also: [file control opcodes]
8150: */
8151: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8152:
8153: /*
8154: ** CAPI3REF: Testing Interface
8155: **
8156: ** ^The sqlite3_test_control() interface is used to read out internal
8157: ** state of SQLite and to inject faults into SQLite for testing
8158: ** purposes. ^The first parameter is an operation code that determines
8159: ** the number, meaning, and operation of all subsequent parameters.
8160: **
8161: ** This interface is not for use by applications. It exists solely
8162: ** for verifying the correct operation of the SQLite library. Depending
8163: ** on how the SQLite library is compiled, this interface might not exist.
8164: **
8165: ** The details of the operation codes, their meanings, the parameters
8166: ** they take, and what they do are all subject to change without notice.
8167: ** Unlike most of the SQLite API, this function is not guaranteed to
8168: ** operate consistently from one release to the next.
8169: */
8170: SQLITE_API int sqlite3_test_control(int op, ...);
8171:
8172: /*
8173: ** CAPI3REF: Testing Interface Operation Codes
8174: **
8175: ** These constants are the valid operation code parameters used
8176: ** as the first argument to [sqlite3_test_control()].
8177: **
8178: ** These parameters and their meanings are subject to change
8179: ** without notice. These values are for testing purposes only.
8180: ** Applications should not use any of these parameters or the
8181: ** [sqlite3_test_control()] interface.
8182: */
8183: #define SQLITE_TESTCTRL_FIRST 5
8184: #define SQLITE_TESTCTRL_PRNG_SAVE 5
8185: #define SQLITE_TESTCTRL_PRNG_RESTORE 6
8186: #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8187: #define SQLITE_TESTCTRL_BITVEC_TEST 8
8188: #define SQLITE_TESTCTRL_FAULT_INSTALL 9
8189: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8190: #define SQLITE_TESTCTRL_PENDING_BYTE 11
8191: #define SQLITE_TESTCTRL_ASSERT 12
8192: #define SQLITE_TESTCTRL_ALWAYS 13
8193: #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8194: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8195: #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8196: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8197: #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8198: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8199: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8200: #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8201: #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8202: #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8203: #define SQLITE_TESTCTRL_BYTEORDER 22
8204: #define SQLITE_TESTCTRL_ISINIT 23
8205: #define SQLITE_TESTCTRL_SORTER_MMAP 24
8206: #define SQLITE_TESTCTRL_IMPOSTER 25
8207: #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8208: #define SQLITE_TESTCTRL_RESULT_INTREAL 27
8209: #define SQLITE_TESTCTRL_PRNG_SEED 28
8210: #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8211: #define SQLITE_TESTCTRL_SEEK_COUNT 30
8212: #define SQLITE_TESTCTRL_TRACEFLAGS 31
8213: #define SQLITE_TESTCTRL_TUNE 32
8214: #define SQLITE_TESTCTRL_LOGEST 33
8215: #define SQLITE_TESTCTRL_USELONGDOUBLE 34
8216: #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8217:
8218: /*
8219: ** CAPI3REF: SQL Keyword Checking
8220: **
8221: ** These routines provide access to the set of SQL language keywords
8222: ** recognized by SQLite. Applications can uses these routines to determine
8223: ** whether or not a specific identifier needs to be escaped (for example,
8224: ** by enclosing in double-quotes) so as not to confuse the parser.
8225: **
8226: ** The sqlite3_keyword_count() interface returns the number of distinct
8227: ** keywords understood by SQLite.
8228: **
8229: ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
8230: ** makes *Z point to that keyword expressed as UTF8 and writes the number
8231: ** of bytes in the keyword into *L. The string that *Z points to is not
8232: ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8233: ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8234: ** or L are NULL or invalid pointers then calls to
8235: ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8236: **
8237: ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8238: ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8239: ** if it is and zero if not.
8240: **
8241: ** The parser used by SQLite is forgiving. It is often possible to use
8242: ** a keyword as an identifier as long as such use does not result in a
8243: ** parsing ambiguity. For example, the statement
8244: ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8245: ** creates a new table named "BEGIN" with three columns named
8246: ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8247: ** using keywords as identifiers. Common techniques used to avoid keyword
8248: ** name collisions include:
8249: ** <ul>
8250: ** <li> Put all identifier names inside double-quotes. This is the official
8251: ** SQL way to escape identifier names.
8252: ** <li> Put identifier names inside [...]. This is not standard SQL,
8253: ** but it is what SQL Server does and so lots of programmers use this
8254: ** technique.
8255: ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8256: ** with "Z".
8257: ** <li> Include a digit somewhere in every identifier name.
8258: ** </ul>
8259: **
8260: ** Note that the number of keywords understood by SQLite can depend on
8261: ** compile-time options. For example, "VACUUM" is not a keyword if
8262: ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8263: ** new keywords may be added to future releases of SQLite.
8264: */
8265: SQLITE_API int sqlite3_keyword_count(void);
8266: SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8267: SQLITE_API int sqlite3_keyword_check(const char*,int);
8268:
8269: /*
8270: ** CAPI3REF: Dynamic String Object
8271: ** KEYWORDS: {dynamic string}
8272: **
8273: ** An instance of the sqlite3_str object contains a dynamically-sized
8274: ** string under construction.
8275: **
8276: ** The lifecycle of an sqlite3_str object is as follows:
8277: ** <ol>
8278: ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8279: ** <li> ^Text is appended to the sqlite3_str object using various
8280: ** methods, such as [sqlite3_str_appendf()].
8281: ** <li> ^The sqlite3_str object is destroyed and the string it created
8282: ** is returned using the [sqlite3_str_finish()] interface.
8283: ** </ol>
8284: */
8285: typedef struct sqlite3_str sqlite3_str;
8286:
8287: /*
8288: ** CAPI3REF: Create A New Dynamic String Object
8289: ** CONSTRUCTOR: sqlite3_str
8290: **
8291: ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8292: ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8293: ** [sqlite3_str_new()] must be freed by a subsequent call to
8294: ** [sqlite3_str_finish(X)].
8295: **
8296: ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8297: ** valid [sqlite3_str] object, though in the event of an out-of-memory
8298: ** error the returned object might be a special singleton that will
8299: ** silently reject new text, always return SQLITE_NOMEM from
8300: ** [sqlite3_str_errcode()], always return 0 for
8301: ** [sqlite3_str_length()], and always return NULL from
8302: ** [sqlite3_str_finish(X)]. It is always safe to use the value
8303: ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8304: ** to any of the other [sqlite3_str] methods.
8305: **
8306: ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8307: ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8308: ** length of the string contained in the [sqlite3_str] object will be
8309: ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8310: ** of [SQLITE_MAX_LENGTH].
8311: */
8312: SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8313:
8314: /*
8315: ** CAPI3REF: Finalize A Dynamic String
8316: ** DESTRUCTOR: sqlite3_str
8317: **
8318: ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8319: ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8320: ** that contains the constructed string. The calling application should
8321: ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8322: ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8323: ** errors were encountered during construction of the string. ^The
8324: ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8325: ** string in [sqlite3_str] object X is zero bytes long.
8326: */
8327: SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8328:
8329: /*
8330: ** CAPI3REF: Add Content To A Dynamic String
8331: ** METHOD: sqlite3_str
8332: **
8333: ** These interfaces add content to an sqlite3_str object previously obtained
8334: ** from [sqlite3_str_new()].
8335: **
8336: ** ^The [sqlite3_str_appendf(X,F,...)] and
8337: ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8338: ** functionality of SQLite to append formatted text onto the end of
8339: ** [sqlite3_str] object X.
8340: **
8341: ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8342: ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8343: ** S must contain at least N non-zero bytes of content. To append a
8344: ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8345: ** method instead.
8346: **
8347: ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8348: ** zero-terminated string S onto the end of [sqlite3_str] object X.
8349: **
8350: ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8351: ** single-byte character C onto the end of [sqlite3_str] object X.
8352: ** ^This method can be used, for example, to add whitespace indentation.
8353: **
8354: ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8355: ** inside [sqlite3_str] object X back to zero bytes in length.
8356: **
8357: ** These methods do not return a result code. ^If an error occurs, that fact
8358: ** is recorded in the [sqlite3_str] object and can be recovered by a
8359: ** subsequent call to [sqlite3_str_errcode(X)].
8360: */
8361: SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8362: SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8363: SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8364: SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8365: SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8366: SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8367:
8368: /*
8369: ** CAPI3REF: Status Of A Dynamic String
8370: ** METHOD: sqlite3_str
8371: **
8372: ** These interfaces return the current status of an [sqlite3_str] object.
8373: **
8374: ** ^If any prior errors have occurred while constructing the dynamic string
8375: ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8376: ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8377: ** [SQLITE_NOMEM] following any out-of-memory error, or
8378: ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8379: ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8380: **
8381: ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8382: ** of the dynamic string under construction in [sqlite3_str] object X.
8383: ** ^The length returned by [sqlite3_str_length(X)] does not include the
8384: ** zero-termination byte.
8385: **
8386: ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8387: ** content of the dynamic string under construction in X. The value
8388: ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8389: ** and might be freed or altered by any subsequent method on the same
8390: ** [sqlite3_str] object. Applications must not used the pointer returned
8391: ** [sqlite3_str_value(X)] after any subsequent method call on the same
8392: ** object. ^Applications may change the content of the string returned
8393: ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8394: ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8395: ** write any byte after any subsequent sqlite3_str method call.
8396: */
8397: SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8398: SQLITE_API int sqlite3_str_length(sqlite3_str*);
8399: SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8400:
8401: /*
8402: ** CAPI3REF: SQLite Runtime Status
8403: **
8404: ** ^These interfaces are used to retrieve runtime status information
8405: ** about the performance of SQLite, and optionally to reset various
8406: ** highwater marks. ^The first argument is an integer code for
8407: ** the specific parameter to measure. ^(Recognized integer codes
8408: ** are of the form [status parameters | SQLITE_STATUS_...].)^
8409: ** ^The current value of the parameter is returned into *pCurrent.
8410: ** ^The highest recorded value is returned in *pHighwater. ^If the
8411: ** resetFlag is true, then the highest record value is reset after
8412: ** *pHighwater is written. ^(Some parameters do not record the highest
8413: ** value. For those parameters
8414: ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8415: ** ^(Other parameters record only the highwater mark and not the current
8416: ** value. For these latter parameters nothing is written into *pCurrent.)^
8417: **
8418: ** ^The sqlite3_status() and sqlite3_status64() routines return
8419: ** SQLITE_OK on success and a non-zero [error code] on failure.
8420: **
8421: ** If either the current value or the highwater mark is too large to
8422: ** be represented by a 32-bit integer, then the values returned by
8423: ** sqlite3_status() are undefined.
8424: **
8425: ** See also: [sqlite3_db_status()]
8426: */
8427: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8428: SQLITE_API int sqlite3_status64(
8429: int op,
8430: sqlite3_int64 *pCurrent,
8431: sqlite3_int64 *pHighwater,
8432: int resetFlag
8433: );
8434:
8435:
8436: /*
8437: ** CAPI3REF: Status Parameters
8438: ** KEYWORDS: {status parameters}
8439: **
8440: ** These integer constants designate various run-time status parameters
8441: ** that can be returned by [sqlite3_status()].
8442: **
8443: ** <dl>
8444: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8445: ** <dd>This parameter is the current amount of memory checked out
8446: ** using [sqlite3_malloc()], either directly or indirectly. The
8447: ** figure includes calls made to [sqlite3_malloc()] by the application
8448: ** and internal memory usage by the SQLite library. Auxiliary page-cache
8449: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8450: ** this parameter. The amount returned is the sum of the allocation
8451: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8452: **
8453: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8454: ** <dd>This parameter records the largest memory allocation request
8455: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8456: ** internal equivalents). Only the value returned in the
8457: ** *pHighwater parameter to [sqlite3_status()] is of interest.
8458: ** The value written into the *pCurrent parameter is undefined.</dd>)^
8459: **
8460: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8461: ** <dd>This parameter records the number of separate memory allocations
8462: ** currently checked out.</dd>)^
8463: **
8464: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8465: ** <dd>This parameter returns the number of pages used out of the
8466: ** [pagecache memory allocator] that was configured using
8467: ** [SQLITE_CONFIG_PAGECACHE]. The
8468: ** value returned is in pages, not in bytes.</dd>)^
8469: **
8470: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8471: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8472: ** <dd>This parameter returns the number of bytes of page cache
8473: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8474: ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8475: ** returned value includes allocations that overflowed because they
8476: ** where too large (they were larger than the "sz" parameter to
8477: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8478: ** no space was left in the page cache.</dd>)^
8479: **
8480: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8481: ** <dd>This parameter records the largest memory allocation request
8482: ** handed to the [pagecache memory allocator]. Only the value returned in the
8483: ** *pHighwater parameter to [sqlite3_status()] is of interest.
8484: ** The value written into the *pCurrent parameter is undefined.</dd>)^
8485: **
8486: ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8487: ** <dd>No longer used.</dd>
8488: **
8489: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8490: ** <dd>No longer used.</dd>
8491: **
8492: ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8493: ** <dd>No longer used.</dd>
8494: **
8495: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8496: ** <dd>The *pHighwater parameter records the deepest parser stack.
8497: ** The *pCurrent value is undefined. The *pHighwater value is only
8498: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8499: ** </dl>
8500: **
8501: ** New status parameters may be added from time to time.
8502: */
8503: #define SQLITE_STATUS_MEMORY_USED 0
8504: #define SQLITE_STATUS_PAGECACHE_USED 1
8505: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8506: #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8507: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8508: #define SQLITE_STATUS_MALLOC_SIZE 5
8509: #define SQLITE_STATUS_PARSER_STACK 6
8510: #define SQLITE_STATUS_PAGECACHE_SIZE 7
8511: #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8512: #define SQLITE_STATUS_MALLOC_COUNT 9
8513:
8514: /*
8515: ** CAPI3REF: Database Connection Status
8516: ** METHOD: sqlite3
8517: **
8518: ** ^This interface is used to retrieve runtime status information
8519: ** about a single [database connection]. ^The first argument is the
8520: ** database connection object to be interrogated. ^The second argument
8521: ** is an integer constant, taken from the set of
8522: ** [SQLITE_DBSTATUS options], that
8523: ** determines the parameter to interrogate. The set of
8524: ** [SQLITE_DBSTATUS options] is likely
8525: ** to grow in future releases of SQLite.
8526: **
8527: ** ^The current value of the requested parameter is written into *pCur
8528: ** and the highest instantaneous value is written into *pHiwtr. ^If
8529: ** the resetFlg is true, then the highest instantaneous value is
8530: ** reset back down to the current value.
8531: **
8532: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8533: ** non-zero [error code] on failure.
8534: **
8535: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8536: */
8537: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8538:
8539: /*
8540: ** CAPI3REF: Status Parameters for database connections
8541: ** KEYWORDS: {SQLITE_DBSTATUS options}
8542: **
8543: ** These constants are the available integer "verbs" that can be passed as
8544: ** the second argument to the [sqlite3_db_status()] interface.
8545: **
8546: ** New verbs may be added in future releases of SQLite. Existing verbs
8547: ** might be discontinued. Applications should check the return code from
8548: ** [sqlite3_db_status()] to make sure that the call worked.
8549: ** The [sqlite3_db_status()] interface will return a non-zero error code
8550: ** if a discontinued or unsupported verb is invoked.
8551: **
8552: ** <dl>
8553: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8554: ** <dd>This parameter returns the number of lookaside memory slots currently
8555: ** checked out.</dd>)^
8556: **
8557: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8558: ** <dd>This parameter returns the number of malloc attempts that were
8559: ** satisfied using lookaside memory. Only the high-water value is meaningful;
8560: ** the current value is always zero.)^
8561: **
8562: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8563: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8564: ** <dd>This parameter returns the number malloc attempts that might have
8565: ** been satisfied using lookaside memory but failed due to the amount of
8566: ** memory requested being larger than the lookaside slot size.
8567: ** Only the high-water value is meaningful;
8568: ** the current value is always zero.)^
8569: **
8570: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8571: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8572: ** <dd>This parameter returns the number malloc attempts that might have
8573: ** been satisfied using lookaside memory but failed due to all lookaside
8574: ** memory already being in use.
8575: ** Only the high-water value is meaningful;
8576: ** the current value is always zero.)^
8577: **
8578: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8579: ** <dd>This parameter returns the approximate number of bytes of heap
8580: ** memory used by all pager caches associated with the database connection.)^
8581: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8582: **
8583: ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8584: ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8585: ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8586: ** pager cache is shared between two or more connections the bytes of heap
8587: ** memory used by that pager cache is divided evenly between the attached
8588: ** connections.)^ In other words, if none of the pager caches associated
8589: ** with the database connection are shared, this request returns the same
8590: ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8591: ** shared, the value returned by this call will be smaller than that returned
8592: ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8593: ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8594: **
8595: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8596: ** <dd>This parameter returns the approximate number of bytes of heap
8597: ** memory used to store the schema for all databases associated
8598: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8599: ** ^The full amount of memory used by the schemas is reported, even if the
8600: ** schema memory is shared with other database connections due to
8601: ** [shared cache mode] being enabled.
8602: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8603: **
8604: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8605: ** <dd>This parameter returns the approximate number of bytes of heap
8606: ** and lookaside memory used by all prepared statements associated with
8607: ** the database connection.)^
8608: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8609: ** </dd>
8610: **
8611: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8612: ** <dd>This parameter returns the number of pager cache hits that have
8613: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8614: ** is always 0.
8615: ** </dd>
8616: **
8617: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8618: ** <dd>This parameter returns the number of pager cache misses that have
8619: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8620: ** is always 0.
8621: ** </dd>
8622: **
8623: ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8624: ** <dd>This parameter returns the number of dirty cache entries that have
8625: ** been written to disk. Specifically, the number of pages written to the
8626: ** wal file in wal mode databases, or the number of pages written to the
8627: ** database file in rollback mode databases. Any pages written as part of
8628: ** transaction rollback or database recovery operations are not included.
8629: ** If an IO or other error occurs while writing a page to disk, the effect
8630: ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8631: ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8632: ** </dd>
8633: **
8634: ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8635: ** <dd>This parameter returns the number of dirty cache entries that have
8636: ** been written to disk in the middle of a transaction due to the page
8637: ** cache overflowing. Transactions are more efficient if they are written
8638: ** to disk all at once. When pages spill mid-transaction, that introduces
8639: ** additional overhead. This parameter can be used help identify
8640: ** inefficiencies that can be resolved by increasing the cache size.
8641: ** </dd>
8642: **
8643: ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8644: ** <dd>This parameter returns zero for the current value if and only if
8645: ** all foreign key constraints (deferred or immediate) have been
8646: ** resolved.)^ ^The highwater mark is always 0.
8647: ** </dd>
8648: ** </dl>
8649: */
8650: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8651: #define SQLITE_DBSTATUS_CACHE_USED 1
8652: #define SQLITE_DBSTATUS_SCHEMA_USED 2
8653: #define SQLITE_DBSTATUS_STMT_USED 3
8654: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8655: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8656: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8657: #define SQLITE_DBSTATUS_CACHE_HIT 7
8658: #define SQLITE_DBSTATUS_CACHE_MISS 8
8659: #define SQLITE_DBSTATUS_CACHE_WRITE 9
8660: #define SQLITE_DBSTATUS_DEFERRED_FKS 10
8661: #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8662: #define SQLITE_DBSTATUS_CACHE_SPILL 12
8663: #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8664:
8665:
8666: /*
8667: ** CAPI3REF: Prepared Statement Status
8668: ** METHOD: sqlite3_stmt
8669: **
8670: ** ^(Each prepared statement maintains various
8671: ** [SQLITE_STMTSTATUS counters] that measure the number
8672: ** of times it has performed specific operations.)^ These counters can
8673: ** be used to monitor the performance characteristics of the prepared
8674: ** statements. For example, if the number of table steps greatly exceeds
8675: ** the number of table searches or result rows, that would tend to indicate
8676: ** that the prepared statement is using a full table scan rather than
8677: ** an index.
8678: **
8679: ** ^(This interface is used to retrieve and reset counter values from
8680: ** a [prepared statement]. The first argument is the prepared statement
8681: ** object to be interrogated. The second argument
8682: ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8683: ** to be interrogated.)^
8684: ** ^The current value of the requested counter is returned.
8685: ** ^If the resetFlg is true, then the counter is reset to zero after this
8686: ** interface call returns.
8687: **
8688: ** See also: [sqlite3_status()] and [sqlite3_db_status()].
8689: */
8690: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8691:
8692: /*
8693: ** CAPI3REF: Status Parameters for prepared statements
8694: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8695: **
8696: ** These preprocessor macros define integer codes that name counter
8697: ** values associated with the [sqlite3_stmt_status()] interface.
8698: ** The meanings of the various counters are as follows:
8699: **
8700: ** <dl>
8701: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8702: ** <dd>^This is the number of times that SQLite has stepped forward in
8703: ** a table as part of a full table scan. Large numbers for this counter
8704: ** may indicate opportunities for performance improvement through
8705: ** careful use of indices.</dd>
8706: **
8707: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8708: ** <dd>^This is the number of sort operations that have occurred.
8709: ** A non-zero value in this counter may indicate an opportunity to
8710: ** improvement performance through careful use of indices.</dd>
8711: **
8712: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8713: ** <dd>^This is the number of rows inserted into transient indices that
8714: ** were created automatically in order to help joins run faster.
8715: ** A non-zero value in this counter may indicate an opportunity to
8716: ** improvement performance by adding permanent indices that do not
8717: ** need to be reinitialized each time the statement is run.</dd>
8718: **
8719: ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8720: ** <dd>^This is the number of virtual machine operations executed
8721: ** by the prepared statement if that number is less than or equal
8722: ** to 2147483647. The number of virtual machine operations can be
8723: ** used as a proxy for the total work done by the prepared statement.
8724: ** If the number of virtual machine operations exceeds 2147483647
8725: ** then the value returned by this statement status code is undefined.
8726: **
8727: ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8728: ** <dd>^This is the number of times that the prepare statement has been
8729: ** automatically regenerated due to schema changes or changes to
8730: ** [bound parameters] that might affect the query plan.
8731: **
8732: ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8733: ** <dd>^This is the number of times that the prepared statement has
8734: ** been run. A single "run" for the purposes of this counter is one
8735: ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8736: ** The counter is incremented on the first [sqlite3_step()] call of each
8737: ** cycle.
8738: **
8739: ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8740: ** [[SQLITE_STMTSTATUS_FILTER HIT]]
8741: ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8742: ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8743: ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8744: ** step was bypassed because a Bloom filter returned not-found. The
8745: ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8746: ** times that the Bloom filter returned a find, and thus the join step
8747: ** had to be processed as normal.
8748: **
8749: ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8750: ** <dd>^This is the approximate number of bytes of heap memory
8751: ** used to store the prepared statement. ^This value is not actually
8752: ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8753: ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8754: ** </dd>
8755: ** </dl>
8756: */
8757: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8758: #define SQLITE_STMTSTATUS_SORT 2
8759: #define SQLITE_STMTSTATUS_AUTOINDEX 3
8760: #define SQLITE_STMTSTATUS_VM_STEP 4
8761: #define SQLITE_STMTSTATUS_REPREPARE 5
8762: #define SQLITE_STMTSTATUS_RUN 6
8763: #define SQLITE_STMTSTATUS_FILTER_MISS 7
8764: #define SQLITE_STMTSTATUS_FILTER_HIT 8
8765: #define SQLITE_STMTSTATUS_MEMUSED 99
8766:
8767: /*
8768: ** CAPI3REF: Custom Page Cache Object
8769: **
8770: ** The sqlite3_pcache type is opaque. It is implemented by
8771: ** the pluggable module. The SQLite core has no knowledge of
8772: ** its size or internal structure and never deals with the
8773: ** sqlite3_pcache object except by holding and passing pointers
8774: ** to the object.
8775: **
8776: ** See [sqlite3_pcache_methods2] for additional information.
8777: */
8778: typedef struct sqlite3_pcache sqlite3_pcache;
8779:
8780: /*
8781: ** CAPI3REF: Custom Page Cache Object
8782: **
8783: ** The sqlite3_pcache_page object represents a single page in the
8784: ** page cache. The page cache will allocate instances of this
8785: ** object. Various methods of the page cache use pointers to instances
8786: ** of this object as parameters or as their return value.
8787: **
8788: ** See [sqlite3_pcache_methods2] for additional information.
8789: */
8790: typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8791: struct sqlite3_pcache_page {
8792: void *pBuf; /* The content of the page */
8793: void *pExtra; /* Extra information associated with the page */
8794: };
8795:
8796: /*
8797: ** CAPI3REF: Application Defined Page Cache.
8798: ** KEYWORDS: {page cache}
8799: **
8800: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8801: ** register an alternative page cache implementation by passing in an
8802: ** instance of the sqlite3_pcache_methods2 structure.)^
8803: ** In many applications, most of the heap memory allocated by
8804: ** SQLite is used for the page cache.
8805: ** By implementing a
8806: ** custom page cache using this API, an application can better control
8807: ** the amount of memory consumed by SQLite, the way in which
8808: ** that memory is allocated and released, and the policies used to
8809: ** determine exactly which parts of a database file are cached and for
8810: ** how long.
8811: **
8812: ** The alternative page cache mechanism is an
8813: ** extreme measure that is only needed by the most demanding applications.
8814: ** The built-in page cache is recommended for most uses.
8815: **
8816: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8817: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8818: ** the application may discard the parameter after the call to
8819: ** [sqlite3_config()] returns.)^
8820: **
8821: ** [[the xInit() page cache method]]
8822: ** ^(The xInit() method is called once for each effective
8823: ** call to [sqlite3_initialize()])^
8824: ** (usually only once during the lifetime of the process). ^(The xInit()
8825: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8826: ** The intent of the xInit() method is to set up global data structures
8827: ** required by the custom page cache implementation.
8828: ** ^(If the xInit() method is NULL, then the
8829: ** built-in default page cache is used instead of the application defined
8830: ** page cache.)^
8831: **
8832: ** [[the xShutdown() page cache method]]
8833: ** ^The xShutdown() method is called by [sqlite3_shutdown()].
8834: ** It can be used to clean up
8835: ** any outstanding resources before process shutdown, if required.
8836: ** ^The xShutdown() method may be NULL.
8837: **
8838: ** ^SQLite automatically serializes calls to the xInit method,
8839: ** so the xInit method need not be threadsafe. ^The
8840: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
8841: ** not need to be threadsafe either. All other methods must be threadsafe
8842: ** in multithreaded applications.
8843: **
8844: ** ^SQLite will never invoke xInit() more than once without an intervening
8845: ** call to xShutdown().
8846: **
8847: ** [[the xCreate() page cache methods]]
8848: ** ^SQLite invokes the xCreate() method to construct a new cache instance.
8849: ** SQLite will typically create one cache instance for each open database file,
8850: ** though this is not guaranteed. ^The
8851: ** first parameter, szPage, is the size in bytes of the pages that must
8852: ** be allocated by the cache. ^szPage will always a power of two. ^The
8853: ** second parameter szExtra is a number of bytes of extra storage
8854: ** associated with each page cache entry. ^The szExtra parameter will
8855: ** a number less than 250. SQLite will use the
8856: ** extra szExtra bytes on each page to store metadata about the underlying
8857: ** database page on disk. The value passed into szExtra depends
8858: ** on the SQLite version, the target platform, and how SQLite was compiled.
8859: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8860: ** created will be used to cache database pages of a file stored on disk, or
8861: ** false if it is used for an in-memory database. The cache implementation
8862: ** does not have to do anything special based with the value of bPurgeable;
8863: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8864: ** never invoke xUnpin() except to deliberately delete a page.
8865: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8866: ** false will always have the "discard" flag set to true.
8867: ** ^Hence, a cache created with bPurgeable false will
8868: ** never contain any unpinned pages.
8869: **
8870: ** [[the xCachesize() page cache method]]
8871: ** ^(The xCachesize() method may be called at any time by SQLite to set the
8872: ** suggested maximum cache-size (number of pages stored by) the cache
8873: ** instance passed as the first argument. This is the value configured using
8874: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8875: ** parameter, the implementation is not required to do anything with this
8876: ** value; it is advisory only.
8877: **
8878: ** [[the xPagecount() page cache methods]]
8879: ** The xPagecount() method must return the number of pages currently
8880: ** stored in the cache, both pinned and unpinned.
8881: **
8882: ** [[the xFetch() page cache methods]]
8883: ** The xFetch() method locates a page in the cache and returns a pointer to
8884: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8885: ** The pBuf element of the returned sqlite3_pcache_page object will be a
8886: ** pointer to a buffer of szPage bytes used to store the content of a
8887: ** single database page. The pExtra element of sqlite3_pcache_page will be
8888: ** a pointer to the szExtra bytes of extra storage that SQLite has requested
8889: ** for each entry in the page cache.
8890: **
8891: ** The page to be fetched is determined by the key. ^The minimum key value
8892: ** is 1. After it has been retrieved using xFetch, the page is considered
8893: ** to be "pinned".
8894: **
8895: ** If the requested page is already in the page cache, then the page cache
8896: ** implementation must return a pointer to the page buffer with its content
8897: ** intact. If the requested page is not already in the cache, then the
8898: ** cache implementation should use the value of the createFlag
8899: ** parameter to help it determined what action to take:
8900: **
8901: ** <table border=1 width=85% align=center>
8902: ** <tr><th> createFlag <th> Behavior when page is not already in cache
8903: ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8904: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8905: ** Otherwise return NULL.
8906: ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8907: ** NULL if allocating a new page is effectively impossible.
8908: ** </table>
8909: **
8910: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8911: ** will only use a createFlag of 2 after a prior call with a createFlag of 1
8912: ** failed.)^ In between the xFetch() calls, SQLite may
8913: ** attempt to unpin one or more cache pages by spilling the content of
8914: ** pinned pages to disk and synching the operating system disk cache.
8915: **
8916: ** [[the xUnpin() page cache method]]
8917: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8918: ** as its second argument. If the third parameter, discard, is non-zero,
8919: ** then the page must be evicted from the cache.
8920: ** ^If the discard parameter is
8921: ** zero, then the page may be discarded or retained at the discretion of
8922: ** page cache implementation. ^The page cache implementation
8923: ** may choose to evict unpinned pages at any time.
8924: **
8925: ** The cache must not perform any reference counting. A single
8926: ** call to xUnpin() unpins the page regardless of the number of prior calls
8927: ** to xFetch().
8928: **
8929: ** [[the xRekey() page cache methods]]
8930: ** The xRekey() method is used to change the key value associated with the
8931: ** page passed as the second argument. If the cache
8932: ** previously contains an entry associated with newKey, it must be
8933: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8934: ** to be pinned.
8935: **
8936: ** When SQLite calls the xTruncate() method, the cache must discard all
8937: ** existing cache entries with page numbers (keys) greater than or equal
8938: ** to the value of the iLimit parameter passed to xTruncate(). If any
8939: ** of these pages are pinned, they are implicitly unpinned, meaning that
8940: ** they can be safely discarded.
8941: **
8942: ** [[the xDestroy() page cache method]]
8943: ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8944: ** All resources associated with the specified cache should be freed. ^After
8945: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8946: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8947: ** functions.
8948: **
8949: ** [[the xShrink() page cache method]]
8950: ** ^SQLite invokes the xShrink() method when it wants the page cache to
8951: ** free up as much of heap memory as possible. The page cache implementation
8952: ** is not obligated to free any memory, but well-behaved implementations should
8953: ** do their best.
8954: */
8955: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8956: struct sqlite3_pcache_methods2 {
8957: int iVersion;
8958: void *pArg;
8959: int (*xInit)(void*);
8960: void (*xShutdown)(void*);
8961: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8962: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8963: int (*xPagecount)(sqlite3_pcache*);
8964: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8965: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8966: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8967: unsigned oldKey, unsigned newKey);
8968: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8969: void (*xDestroy)(sqlite3_pcache*);
8970: void (*xShrink)(sqlite3_pcache*);
8971: };
8972:
8973: /*
8974: ** This is the obsolete pcache_methods object that has now been replaced
8975: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8976: ** retained in the header file for backwards compatibility only.
8977: */
8978: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8979: struct sqlite3_pcache_methods {
8980: void *pArg;
8981: int (*xInit)(void*);
8982: void (*xShutdown)(void*);
8983: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8984: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8985: int (*xPagecount)(sqlite3_pcache*);
8986: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8987: void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8988: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8989: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8990: void (*xDestroy)(sqlite3_pcache*);
8991: };
8992:
8993:
8994: /*
8995: ** CAPI3REF: Online Backup Object
8996: **
8997: ** The sqlite3_backup object records state information about an ongoing
8998: ** online backup operation. ^The sqlite3_backup object is created by
8999: ** a call to [sqlite3_backup_init()] and is destroyed by a call to
9000: ** [sqlite3_backup_finish()].
9001: **
9002: ** See Also: [Using the SQLite Online Backup API]
9003: */
9004: typedef struct sqlite3_backup sqlite3_backup;
9005:
9006: /*
9007: ** CAPI3REF: Online Backup API.
9008: **
9009: ** The backup API copies the content of one database into another.
9010: ** It is useful either for creating backups of databases or
9011: ** for copying in-memory databases to or from persistent files.
9012: **
9013: ** See Also: [Using the SQLite Online Backup API]
9014: **
9015: ** ^SQLite holds a write transaction open on the destination database file
9016: ** for the duration of the backup operation.
9017: ** ^The source database is read-locked only while it is being read;
9018: ** it is not locked continuously for the entire backup operation.
9019: ** ^Thus, the backup may be performed on a live source database without
9020: ** preventing other database connections from
9021: ** reading or writing to the source database while the backup is underway.
9022: **
9023: ** ^(To perform a backup operation:
9024: ** <ol>
9025: ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9026: ** backup,
9027: ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9028: ** the data between the two databases, and finally
9029: ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9030: ** associated with the backup operation.
9031: ** </ol>)^
9032: ** There should be exactly one call to sqlite3_backup_finish() for each
9033: ** successful call to sqlite3_backup_init().
9034: **
9035: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9036: **
9037: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9038: ** [database connection] associated with the destination database
9039: ** and the database name, respectively.
9040: ** ^The database name is "main" for the main database, "temp" for the
9041: ** temporary database, or the name specified after the AS keyword in
9042: ** an [ATTACH] statement for an attached database.
9043: ** ^The S and M arguments passed to
9044: ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9045: ** and database name of the source database, respectively.
9046: ** ^The source and destination [database connections] (parameters S and D)
9047: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9048: ** an error.
9049: **
9050: ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9051: ** there is already a read or read-write transaction open on the
9052: ** destination database.
9053: **
9054: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9055: ** returned and an error code and error message are stored in the
9056: ** destination [database connection] D.
9057: ** ^The error code and message for the failed call to sqlite3_backup_init()
9058: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9059: ** [sqlite3_errmsg16()] functions.
9060: ** ^A successful call to sqlite3_backup_init() returns a pointer to an
9061: ** [sqlite3_backup] object.
9062: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9063: ** sqlite3_backup_finish() functions to perform the specified backup
9064: ** operation.
9065: **
9066: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9067: **
9068: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9069: ** the source and destination databases specified by [sqlite3_backup] object B.
9070: ** ^If N is negative, all remaining source pages are copied.
9071: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9072: ** are still more pages to be copied, then the function returns [SQLITE_OK].
9073: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9074: ** from source to destination, then it returns [SQLITE_DONE].
9075: ** ^If an error occurs while running sqlite3_backup_step(B,N),
9076: ** then an [error code] is returned. ^As well as [SQLITE_OK] and
9077: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9078: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9079: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9080: **
9081: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9082: ** <ol>
9083: ** <li> the destination database was opened read-only, or
9084: ** <li> the destination database is using write-ahead-log journaling
9085: ** and the destination and source page sizes differ, or
9086: ** <li> the destination database is an in-memory database and the
9087: ** destination and source page sizes differ.
9088: ** </ol>)^
9089: **
9090: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9091: ** the [sqlite3_busy_handler | busy-handler function]
9092: ** is invoked (if one is specified). ^If the
9093: ** busy-handler returns non-zero before the lock is available, then
9094: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9095: ** sqlite3_backup_step() can be retried later. ^If the source
9096: ** [database connection]
9097: ** is being used to write to the source database when sqlite3_backup_step()
9098: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9099: ** case the call to sqlite3_backup_step() can be retried later on. ^(If
9100: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9101: ** [SQLITE_READONLY] is returned, then
9102: ** there is no point in retrying the call to sqlite3_backup_step(). These
9103: ** errors are considered fatal.)^ The application must accept
9104: ** that the backup operation has failed and pass the backup operation handle
9105: ** to the sqlite3_backup_finish() to release associated resources.
9106: **
9107: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9108: ** on the destination file. ^The exclusive lock is not released until either
9109: ** sqlite3_backup_finish() is called or the backup operation is complete
9110: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9111: ** sqlite3_backup_step() obtains a [shared lock] on the source database that
9112: ** lasts for the duration of the sqlite3_backup_step() call.
9113: ** ^Because the source database is not locked between calls to
9114: ** sqlite3_backup_step(), the source database may be modified mid-way
9115: ** through the backup process. ^If the source database is modified by an
9116: ** external process or via a database connection other than the one being
9117: ** used by the backup operation, then the backup will be automatically
9118: ** restarted by the next call to sqlite3_backup_step(). ^If the source
9119: ** database is modified by the using the same database connection as is used
9120: ** by the backup operation, then the backup database is automatically
9121: ** updated at the same time.
9122: **
9123: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9124: **
9125: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9126: ** application wishes to abandon the backup operation, the application
9127: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9128: ** ^The sqlite3_backup_finish() interfaces releases all
9129: ** resources associated with the [sqlite3_backup] object.
9130: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9131: ** active write-transaction on the destination database is rolled back.
9132: ** The [sqlite3_backup] object is invalid
9133: ** and may not be used following a call to sqlite3_backup_finish().
9134: **
9135: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9136: ** sqlite3_backup_step() errors occurred, regardless or whether or not
9137: ** sqlite3_backup_step() completed.
9138: ** ^If an out-of-memory condition or IO error occurred during any prior
9139: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9140: ** sqlite3_backup_finish() returns the corresponding [error code].
9141: **
9142: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9143: ** is not a permanent error and does not affect the return value of
9144: ** sqlite3_backup_finish().
9145: **
9146: ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9147: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9148: **
9149: ** ^The sqlite3_backup_remaining() routine returns the number of pages still
9150: ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9151: ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9152: ** in the source database at the conclusion of the most recent
9153: ** sqlite3_backup_step().
9154: ** ^(The values returned by these functions are only updated by
9155: ** sqlite3_backup_step(). If the source database is modified in a way that
9156: ** changes the size of the source database or the number of pages remaining,
9157: ** those changes are not reflected in the output of sqlite3_backup_pagecount()
9158: ** and sqlite3_backup_remaining() until after the next
9159: ** sqlite3_backup_step().)^
9160: **
9161: ** <b>Concurrent Usage of Database Handles</b>
9162: **
9163: ** ^The source [database connection] may be used by the application for other
9164: ** purposes while a backup operation is underway or being initialized.
9165: ** ^If SQLite is compiled and configured to support threadsafe database
9166: ** connections, then the source database connection may be used concurrently
9167: ** from within other threads.
9168: **
9169: ** However, the application must guarantee that the destination
9170: ** [database connection] is not passed to any other API (by any thread) after
9171: ** sqlite3_backup_init() is called and before the corresponding call to
9172: ** sqlite3_backup_finish(). SQLite does not currently check to see
9173: ** if the application incorrectly accesses the destination [database connection]
9174: ** and so no error code is reported, but the operations may malfunction
9175: ** nevertheless. Use of the destination database connection while a
9176: ** backup is in progress might also cause a mutex deadlock.
9177: **
9178: ** If running in [shared cache mode], the application must
9179: ** guarantee that the shared cache used by the destination database
9180: ** is not accessed while the backup is running. In practice this means
9181: ** that the application must guarantee that the disk file being
9182: ** backed up to is not accessed by any connection within the process,
9183: ** not just the specific connection that was passed to sqlite3_backup_init().
9184: **
9185: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9186: ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9187: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9188: ** APIs are not strictly speaking threadsafe. If they are invoked at the
9189: ** same time as another thread is invoking sqlite3_backup_step() it is
9190: ** possible that they return invalid values.
9191: */
9192: SQLITE_API sqlite3_backup *sqlite3_backup_init(
9193: sqlite3 *pDest, /* Destination database handle */
9194: const char *zDestName, /* Destination database name */
9195: sqlite3 *pSource, /* Source database handle */
9196: const char *zSourceName /* Source database name */
9197: );
9198: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9199: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9200: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9201: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9202:
9203: /*
9204: ** CAPI3REF: Unlock Notification
9205: ** METHOD: sqlite3
9206: **
9207: ** ^When running in shared-cache mode, a database operation may fail with
9208: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9209: ** individual tables within the shared-cache cannot be obtained. See
9210: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9211: ** ^This API may be used to register a callback that SQLite will invoke
9212: ** when the connection currently holding the required lock relinquishes it.
9213: ** ^This API is only available if the library was compiled with the
9214: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9215: **
9216: ** See Also: [Using the SQLite Unlock Notification Feature].
9217: **
9218: ** ^Shared-cache locks are released when a database connection concludes
9219: ** its current transaction, either by committing it or rolling it back.
9220: **
9221: ** ^When a connection (known as the blocked connection) fails to obtain a
9222: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9223: ** identity of the database connection (the blocking connection) that
9224: ** has locked the required resource is stored internally. ^After an
9225: ** application receives an SQLITE_LOCKED error, it may call the
9226: ** sqlite3_unlock_notify() method with the blocked connection handle as
9227: ** the first argument to register for a callback that will be invoked
9228: ** when the blocking connections current transaction is concluded. ^The
9229: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9230: ** call that concludes the blocking connection's transaction.
9231: **
9232: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9233: ** there is a chance that the blocking connection will have already
9234: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9235: ** If this happens, then the specified callback is invoked immediately,
9236: ** from within the call to sqlite3_unlock_notify().)^
9237: **
9238: ** ^If the blocked connection is attempting to obtain a write-lock on a
9239: ** shared-cache table, and more than one other connection currently holds
9240: ** a read-lock on the same table, then SQLite arbitrarily selects one of
9241: ** the other connections to use as the blocking connection.
9242: **
9243: ** ^(There may be at most one unlock-notify callback registered by a
9244: ** blocked connection. If sqlite3_unlock_notify() is called when the
9245: ** blocked connection already has a registered unlock-notify callback,
9246: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9247: ** called with a NULL pointer as its second argument, then any existing
9248: ** unlock-notify callback is cancelled. ^The blocked connections
9249: ** unlock-notify callback may also be cancelled by closing the blocked
9250: ** connection using [sqlite3_close()].
9251: **
9252: ** The unlock-notify callback is not reentrant. If an application invokes
9253: ** any sqlite3_xxx API functions from within an unlock-notify callback, a
9254: ** crash or deadlock may be the result.
9255: **
9256: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9257: ** returns SQLITE_OK.
9258: **
9259: ** <b>Callback Invocation Details</b>
9260: **
9261: ** When an unlock-notify callback is registered, the application provides a
9262: ** single void* pointer that is passed to the callback when it is invoked.
9263: ** However, the signature of the callback function allows SQLite to pass
9264: ** it an array of void* context pointers. The first argument passed to
9265: ** an unlock-notify callback is a pointer to an array of void* pointers,
9266: ** and the second is the number of entries in the array.
9267: **
9268: ** When a blocking connection's transaction is concluded, there may be
9269: ** more than one blocked connection that has registered for an unlock-notify
9270: ** callback. ^If two or more such blocked connections have specified the
9271: ** same callback function, then instead of invoking the callback function
9272: ** multiple times, it is invoked once with the set of void* context pointers
9273: ** specified by the blocked connections bundled together into an array.
9274: ** This gives the application an opportunity to prioritize any actions
9275: ** related to the set of unblocked database connections.
9276: **
9277: ** <b>Deadlock Detection</b>
9278: **
9279: ** Assuming that after registering for an unlock-notify callback a
9280: ** database waits for the callback to be issued before taking any further
9281: ** action (a reasonable assumption), then using this API may cause the
9282: ** application to deadlock. For example, if connection X is waiting for
9283: ** connection Y's transaction to be concluded, and similarly connection
9284: ** Y is waiting on connection X's transaction, then neither connection
9285: ** will proceed and the system may remain deadlocked indefinitely.
9286: **
9287: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9288: ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9289: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9290: ** unlock-notify callback is registered. The system is said to be in
9291: ** a deadlocked state if connection A has registered for an unlock-notify
9292: ** callback on the conclusion of connection B's transaction, and connection
9293: ** B has itself registered for an unlock-notify callback when connection
9294: ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9295: ** the system is also considered to be deadlocked if connection B has
9296: ** registered for an unlock-notify callback on the conclusion of connection
9297: ** C's transaction, where connection C is waiting on connection A. ^Any
9298: ** number of levels of indirection are allowed.
9299: **
9300: ** <b>The "DROP TABLE" Exception</b>
9301: **
9302: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9303: ** always appropriate to call sqlite3_unlock_notify(). There is however,
9304: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9305: ** SQLite checks if there are any currently executing SELECT statements
9306: ** that belong to the same connection. If there are, SQLITE_LOCKED is
9307: ** returned. In this case there is no "blocking connection", so invoking
9308: ** sqlite3_unlock_notify() results in the unlock-notify callback being
9309: ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9310: ** or "DROP INDEX" query, an infinite loop might be the result.
9311: **
9312: ** One way around this problem is to check the extended error code returned
9313: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9314: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9315: ** the special "DROP TABLE/INDEX" case, the extended error code is just
9316: ** SQLITE_LOCKED.)^
9317: */
9318: SQLITE_API int sqlite3_unlock_notify(
9319: sqlite3 *pBlocked, /* Waiting connection */
9320: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9321: void *pNotifyArg /* Argument to pass to xNotify */
9322: );
9323:
9324:
9325: /*
9326: ** CAPI3REF: String Comparison
9327: **
9328: ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9329: ** and extensions to compare the contents of two buffers containing UTF-8
9330: ** strings in a case-independent fashion, using the same definition of "case
9331: ** independence" that SQLite uses internally when comparing identifiers.
9332: */
9333: SQLITE_API int sqlite3_stricmp(const char *, const char *);
9334: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9335:
9336: /*
9337: ** CAPI3REF: String Globbing
9338: *
9339: ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9340: ** string X matches the [GLOB] pattern P.
9341: ** ^The definition of [GLOB] pattern matching used in
9342: ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9343: ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9344: ** is case sensitive.
9345: **
9346: ** Note that this routine returns zero on a match and non-zero if the strings
9347: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9348: **
9349: ** See also: [sqlite3_strlike()].
9350: */
9351: SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9352:
9353: /*
9354: ** CAPI3REF: String LIKE Matching
9355: *
9356: ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9357: ** string X matches the [LIKE] pattern P with escape character E.
9358: ** ^The definition of [LIKE] pattern matching used in
9359: ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9360: ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9361: ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9362: ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9363: ** insensitive - equivalent upper and lower case ASCII characters match
9364: ** one another.
9365: **
9366: ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9367: ** only ASCII characters are case folded.
9368: **
9369: ** Note that this routine returns zero on a match and non-zero if the strings
9370: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9371: **
9372: ** See also: [sqlite3_strglob()].
9373: */
9374: SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9375:
9376: /*
9377: ** CAPI3REF: Error Logging Interface
9378: **
9379: ** ^The [sqlite3_log()] interface writes a message into the [error log]
9380: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9381: ** ^If logging is enabled, the zFormat string and subsequent arguments are
9382: ** used with [sqlite3_snprintf()] to generate the final output string.
9383: **
9384: ** The sqlite3_log() interface is intended for use by extensions such as
9385: ** virtual tables, collating functions, and SQL functions. While there is
9386: ** nothing to prevent an application from calling sqlite3_log(), doing so
9387: ** is considered bad form.
9388: **
9389: ** The zFormat string must not be NULL.
9390: **
9391: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9392: ** will not use dynamically allocated memory. The log message is stored in
9393: ** a fixed-length buffer on the stack. If the log message is longer than
9394: ** a few hundred characters, it will be truncated to the length of the
9395: ** buffer.
9396: */
9397: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9398:
9399: /*
9400: ** CAPI3REF: Write-Ahead Log Commit Hook
9401: ** METHOD: sqlite3
9402: **
9403: ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9404: ** is invoked each time data is committed to a database in wal mode.
9405: **
9406: ** ^(The callback is invoked by SQLite after the commit has taken place and
9407: ** the associated write-lock on the database released)^, so the implementation
9408: ** may read, write or [checkpoint] the database as required.
9409: **
9410: ** ^The first parameter passed to the callback function when it is invoked
9411: ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9412: ** registering the callback. ^The second is a copy of the database handle.
9413: ** ^The third parameter is the name of the database that was written to -
9414: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9415: ** is the number of pages currently in the write-ahead log file,
9416: ** including those that were just committed.
9417: **
9418: ** The callback function should normally return [SQLITE_OK]. ^If an error
9419: ** code is returned, that error will propagate back up through the
9420: ** SQLite code base to cause the statement that provoked the callback
9421: ** to report an error, though the commit will have still occurred. If the
9422: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9423: ** that does not correspond to any valid SQLite error code, the results
9424: ** are undefined.
9425: **
9426: ** A single database handle may have at most a single write-ahead log callback
9427: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9428: ** previously registered write-ahead log callback. ^The return value is
9429: ** a copy of the third parameter from the previous call, if any, or 0.
9430: ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9431: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9432: ** overwrite any prior [sqlite3_wal_hook()] settings.
9433: */
9434: SQLITE_API void *sqlite3_wal_hook(
9435: sqlite3*,
9436: int(*)(void *,sqlite3*,const char*,int),
9437: void*
9438: );
9439:
9440: /*
9441: ** CAPI3REF: Configure an auto-checkpoint
9442: ** METHOD: sqlite3
9443: **
9444: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9445: ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9446: ** to automatically [checkpoint]
9447: ** after committing a transaction if there are N or
9448: ** more frames in the [write-ahead log] file. ^Passing zero or
9449: ** a negative value as the nFrame parameter disables automatic
9450: ** checkpoints entirely.
9451: **
9452: ** ^The callback registered by this function replaces any existing callback
9453: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9454: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9455: ** configured by this function.
9456: **
9457: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9458: ** from SQL.
9459: **
9460: ** ^Checkpoints initiated by this mechanism are
9461: ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9462: **
9463: ** ^Every new [database connection] defaults to having the auto-checkpoint
9464: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9465: ** pages. The use of this interface
9466: ** is only necessary if the default setting is found to be suboptimal
9467: ** for a particular application.
9468: */
9469: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9470:
9471: /*
9472: ** CAPI3REF: Checkpoint a database
9473: ** METHOD: sqlite3
9474: **
9475: ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9476: ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9477: **
9478: ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9479: ** [write-ahead log] for database X on [database connection] D to be
9480: ** transferred into the database file and for the write-ahead log to
9481: ** be reset. See the [checkpointing] documentation for addition
9482: ** information.
9483: **
9484: ** This interface used to be the only way to cause a checkpoint to
9485: ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9486: ** interface was added. This interface is retained for backwards
9487: ** compatibility and as a convenience for applications that need to manually
9488: ** start a callback but which do not need the full power (and corresponding
9489: ** complication) of [sqlite3_wal_checkpoint_v2()].
9490: */
9491: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9492:
9493: /*
9494: ** CAPI3REF: Checkpoint a database
9495: ** METHOD: sqlite3
9496: **
9497: ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9498: ** operation on database X of [database connection] D in mode M. Status
9499: ** information is written back into integers pointed to by L and C.)^
9500: ** ^(The M parameter must be a valid [checkpoint mode]:)^
9501: **
9502: ** <dl>
9503: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9504: ** ^Checkpoint as many frames as possible without waiting for any database
9505: ** readers or writers to finish, then sync the database file if all frames
9506: ** in the log were checkpointed. ^The [busy-handler callback]
9507: ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9508: ** ^On the other hand, passive mode might leave the checkpoint unfinished
9509: ** if there are concurrent readers or writers.
9510: **
9511: ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9512: ** ^This mode blocks (it invokes the
9513: ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9514: ** database writer and all readers are reading from the most recent database
9515: ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9516: ** database file. ^This mode blocks new database writers while it is pending,
9517: ** but new database readers are allowed to continue unimpeded.
9518: **
9519: ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9520: ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9521: ** that after checkpointing the log file it blocks (calls the
9522: ** [busy-handler callback])
9523: ** until all readers are reading from the database file only. ^This ensures
9524: ** that the next writer will restart the log file from the beginning.
9525: ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9526: ** database writer attempts while it is pending, but does not impede readers.
9527: **
9528: ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9529: ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9530: ** addition that it also truncates the log file to zero bytes just prior
9531: ** to a successful return.
9532: ** </dl>
9533: **
9534: ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9535: ** the log file or to -1 if the checkpoint could not run because
9536: ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9537: ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9538: ** log file (including any that were already checkpointed before the function
9539: ** was called) or to -1 if the checkpoint could not run due to an error or
9540: ** because the database is not in WAL mode. ^Note that upon successful
9541: ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9542: ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9543: **
9544: ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9545: ** any other process is running a checkpoint operation at the same time, the
9546: ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9547: ** busy-handler configured, it will not be invoked in this case.
9548: **
9549: ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9550: ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9551: ** obtained immediately, and a busy-handler is configured, it is invoked and
9552: ** the writer lock retried until either the busy-handler returns 0 or the lock
9553: ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9554: ** database readers as described above. ^If the busy-handler returns 0 before
9555: ** the writer lock is obtained or while waiting for database readers, the
9556: ** checkpoint operation proceeds from that point in the same way as
9557: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9558: ** without blocking any further. ^SQLITE_BUSY is returned in this case.
9559: **
9560: ** ^If parameter zDb is NULL or points to a zero length string, then the
9561: ** specified operation is attempted on all WAL databases [attached] to
9562: ** [database connection] db. In this case the
9563: ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9564: ** an SQLITE_BUSY error is encountered when processing one or more of the
9565: ** attached WAL databases, the operation is still attempted on any remaining
9566: ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9567: ** error occurs while processing an attached database, processing is abandoned
9568: ** and the error code is returned to the caller immediately. ^If no error
9569: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9570: ** databases, SQLITE_OK is returned.
9571: **
9572: ** ^If database zDb is the name of an attached database that is not in WAL
9573: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9574: ** zDb is not NULL (or a zero length string) and is not the name of any
9575: ** attached database, SQLITE_ERROR is returned to the caller.
9576: **
9577: ** ^Unless it returns SQLITE_MISUSE,
9578: ** the sqlite3_wal_checkpoint_v2() interface
9579: ** sets the error information that is queried by
9580: ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9581: **
9582: ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9583: ** from SQL.
9584: */
9585: SQLITE_API int sqlite3_wal_checkpoint_v2(
9586: sqlite3 *db, /* Database handle */
9587: const char *zDb, /* Name of attached database (or NULL) */
9588: int eMode, /* SQLITE_CHECKPOINT_* value */
9589: int *pnLog, /* OUT: Size of WAL log in frames */
9590: int *pnCkpt /* OUT: Total number of frames checkpointed */
9591: );
9592:
9593: /*
9594: ** CAPI3REF: Checkpoint Mode Values
9595: ** KEYWORDS: {checkpoint mode}
9596: **
9597: ** These constants define all valid values for the "checkpoint mode" passed
9598: ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9599: ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9600: ** meaning of each of these checkpoint modes.
9601: */
9602: #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9603: #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9604: #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9605: #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9606:
9607: /*
9608: ** CAPI3REF: Virtual Table Interface Configuration
9609: **
9610: ** This function may be called by either the [xConnect] or [xCreate] method
9611: ** of a [virtual table] implementation to configure
9612: ** various facets of the virtual table interface.
9613: **
9614: ** If this interface is invoked outside the context of an xConnect or
9615: ** xCreate virtual table method then the behavior is undefined.
9616: **
9617: ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9618: ** [database connection] in which the virtual table is being created and
9619: ** which is passed in as the first argument to the [xConnect] or [xCreate]
9620: ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9621: ** of the [virtual table configuration options]. The presence and meaning
9622: ** of parameters after C depend on which [virtual table configuration option]
9623: ** is used.
9624: */
9625: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9626:
9627: /*
9628: ** CAPI3REF: Virtual Table Configuration Options
9629: ** KEYWORDS: {virtual table configuration options}
9630: ** KEYWORDS: {virtual table configuration option}
9631: **
9632: ** These macros define the various options to the
9633: ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9634: ** can use to customize and optimize their behavior.
9635: **
9636: ** <dl>
9637: ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9638: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9639: ** <dd>Calls of the form
9640: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9641: ** where X is an integer. If X is zero, then the [virtual table] whose
9642: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9643: ** support constraints. In this configuration (which is the default) if
9644: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9645: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9646: ** specified as part of the users SQL statement, regardless of the actual
9647: ** ON CONFLICT mode specified.
9648: **
9649: ** If X is non-zero, then the virtual table implementation guarantees
9650: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9651: ** any modifications to internal or persistent data structures have been made.
9652: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9653: ** is able to roll back a statement or database transaction, and abandon
9654: ** or continue processing the current SQL statement as appropriate.
9655: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9656: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9657: ** had been ABORT.
9658: **
9659: ** Virtual table implementations that are required to handle OR REPLACE
9660: ** must do so within the [xUpdate] method. If a call to the
9661: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9662: ** CONFLICT policy is REPLACE, the virtual table implementation should
9663: ** silently replace the appropriate rows within the xUpdate callback and
9664: ** return SQLITE_OK. Or, if this is not possible, it may return
9665: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9666: ** constraint handling.
9667: ** </dd>
9668: **
9669: ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9670: ** <dd>Calls of the form
9671: ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9672: ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9673: ** prohibits that virtual table from being used from within triggers and
9674: ** views.
9675: ** </dd>
9676: **
9677: ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9678: ** <dd>Calls of the form
9679: ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9680: ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9681: ** identify that virtual table as being safe to use from within triggers
9682: ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9683: ** virtual table can do no serious harm even if it is controlled by a
9684: ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9685: ** flag unless absolutely necessary.
9686: ** </dd>
9687: **
9688: ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
9689: ** <dd>Calls of the form
9690: ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
9691: ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9692: ** instruct the query planner to begin at least a read transaction on
9693: ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
9694: ** virtual table is used.
9695: ** </dd>
9696: ** </dl>
9697: */
9698: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9699: #define SQLITE_VTAB_INNOCUOUS 2
9700: #define SQLITE_VTAB_DIRECTONLY 3
9701: #define SQLITE_VTAB_USES_ALL_SCHEMAS 4
9702:
9703: /*
9704: ** CAPI3REF: Determine The Virtual Table Conflict Policy
9705: **
9706: ** This function may only be called from within a call to the [xUpdate] method
9707: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9708: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9709: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9710: ** of the SQL statement that triggered the call to the [xUpdate] method of the
9711: ** [virtual table].
9712: */
9713: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9714:
9715: /*
9716: ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9717: **
9718: ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9719: ** method of a [virtual table], then it might return true if the
9720: ** column is being fetched as part of an UPDATE operation during which the
9721: ** column value will not change. The virtual table implementation can use
9722: ** this hint as permission to substitute a return value that is less
9723: ** expensive to compute and that the corresponding
9724: ** [xUpdate] method understands as a "no-change" value.
9725: **
9726: ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9727: ** the column is not changed by the UPDATE statement, then the xColumn
9728: ** method can optionally return without setting a result, without calling
9729: ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9730: ** In that case, [sqlite3_value_nochange(X)] will return true for the
9731: ** same column in the [xUpdate] method.
9732: **
9733: ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9734: ** implementations should continue to give a correct answer even if the
9735: ** sqlite3_vtab_nochange() interface were to always return false. In the
9736: ** current implementation, the sqlite3_vtab_nochange() interface does always
9737: ** returns false for the enhanced [UPDATE FROM] statement.
9738: */
9739: SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9740:
9741: /*
9742: ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9743: ** METHOD: sqlite3_index_info
9744: **
9745: ** This function may only be called from within a call to the [xBestIndex]
9746: ** method of a [virtual table]. This function returns a pointer to a string
9747: ** that is the name of the appropriate collation sequence to use for text
9748: ** comparisons on the constraint identified by its arguments.
9749: **
9750: ** The first argument must be the pointer to the [sqlite3_index_info] object
9751: ** that is the first parameter to the xBestIndex() method. The second argument
9752: ** must be an index into the aConstraint[] array belonging to the
9753: ** sqlite3_index_info structure passed to xBestIndex.
9754: **
9755: ** Important:
9756: ** The first parameter must be the same pointer that is passed into the
9757: ** xBestMethod() method. The first parameter may not be a pointer to a
9758: ** different [sqlite3_index_info] object, even an exact copy.
9759: **
9760: ** The return value is computed as follows:
9761: **
9762: ** <ol>
9763: ** <li><p> If the constraint comes from a WHERE clause expression that contains
9764: ** a [COLLATE operator], then the name of the collation specified by
9765: ** that COLLATE operator is returned.
9766: ** <li><p> If there is no COLLATE operator, but the column that is the subject
9767: ** of the constraint specifies an alternative collating sequence via
9768: ** a [COLLATE clause] on the column definition within the CREATE TABLE
9769: ** statement that was passed into [sqlite3_declare_vtab()], then the
9770: ** name of that alternative collating sequence is returned.
9771: ** <li><p> Otherwise, "BINARY" is returned.
9772: ** </ol>
9773: */
9774: SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9775:
9776: /*
9777: ** CAPI3REF: Determine if a virtual table query is DISTINCT
9778: ** METHOD: sqlite3_index_info
9779: **
9780: ** This API may only be used from within an [xBestIndex|xBestIndex method]
9781: ** of a [virtual table] implementation. The result of calling this
9782: ** interface from outside of xBestIndex() is undefined and probably harmful.
9783: **
9784: ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9785: ** 3. The integer returned by sqlite3_vtab_distinct()
9786: ** gives the virtual table additional information about how the query
9787: ** planner wants the output to be ordered. As long as the virtual table
9788: ** can meet the ordering requirements of the query planner, it may set
9789: ** the "orderByConsumed" flag.
9790: **
9791: ** <ol><li value="0"><p>
9792: ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9793: ** that the query planner needs the virtual table to return all rows in the
9794: ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9795: ** [sqlite3_index_info] object. This is the default expectation. If the
9796: ** virtual table outputs all rows in sorted order, then it is always safe for
9797: ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9798: ** the return value from sqlite3_vtab_distinct().
9799: ** <li value="1"><p>
9800: ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9801: ** that the query planner does not need the rows to be returned in sorted order
9802: ** as long as all rows with the same values in all columns identified by the
9803: ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9804: ** is doing a GROUP BY.
9805: ** <li value="2"><p>
9806: ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9807: ** that the query planner does not need the rows returned in any particular
9808: ** order, as long as rows with the same values in all "aOrderBy" columns
9809: ** are adjacent.)^ ^(Furthermore, only a single row for each particular
9810: ** combination of values in the columns identified by the "aOrderBy" field
9811: ** needs to be returned.)^ ^It is always ok for two or more rows with the same
9812: ** values in all "aOrderBy" columns to be returned, as long as all such rows
9813: ** are adjacent. ^The virtual table may, if it chooses, omit extra rows
9814: ** that have the same value for all columns identified by "aOrderBy".
9815: ** ^However omitting the extra rows is optional.
9816: ** This mode is used for a DISTINCT query.
9817: ** <li value="3"><p>
9818: ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means
9819: ** that the query planner needs only distinct rows but it does need the
9820: ** rows to be sorted.)^ ^The virtual table implementation is free to omit
9821: ** rows that are identical in all aOrderBy columns, if it wants to, but
9822: ** it is not required to omit any rows. This mode is used for queries
9823: ** that have both DISTINCT and ORDER BY clauses.
9824: ** </ol>
9825: **
9826: ** ^For the purposes of comparing virtual table output values to see if the
9827: ** values are same value for sorting purposes, two NULL values are considered
9828: ** to be the same. In other words, the comparison operator is "IS"
9829: ** (or "IS NOT DISTINCT FROM") and not "==".
9830: **
9831: ** If a virtual table implementation is unable to meet the requirements
9832: ** specified above, then it must not set the "orderByConsumed" flag in the
9833: ** [sqlite3_index_info] object or an incorrect answer may result.
9834: **
9835: ** ^A virtual table implementation is always free to return rows in any order
9836: ** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9837: ** the "orderByConsumed" flag is unset, the query planner will add extra
9838: ** [bytecode] to ensure that the final results returned by the SQL query are
9839: ** ordered correctly. The use of the "orderByConsumed" flag and the
9840: ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9841: ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
9842: ** flag might help queries against a virtual table to run faster. Being
9843: ** overly aggressive and setting the "orderByConsumed" flag when it is not
9844: ** valid to do so, on the other hand, might cause SQLite to return incorrect
9845: ** results.
9846: */
9847: SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
9848:
9849: /*
9850: ** CAPI3REF: Identify and handle IN constraints in xBestIndex
9851: **
9852: ** This interface may only be used from within an
9853: ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
9854: ** The result of invoking this interface from any other context is
9855: ** undefined and probably harmful.
9856: **
9857: ** ^(A constraint on a virtual table of the form
9858: ** "[IN operator|column IN (...)]" is
9859: ** communicated to the xBestIndex method as a
9860: ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
9861: ** this constraint, it must set the corresponding
9862: ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
9863: ** the usual mode of handling IN operators, SQLite generates [bytecode]
9864: ** that invokes the [xFilter|xFilter() method] once for each value
9865: ** on the right-hand side of the IN operator.)^ Thus the virtual table
9866: ** only sees a single value from the right-hand side of the IN operator
9867: ** at a time.
9868: **
9869: ** In some cases, however, it would be advantageous for the virtual
9870: ** table to see all values on the right-hand of the IN operator all at
9871: ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
9872: **
9873: ** <ol>
9874: ** <li><p>
9875: ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
9876: ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
9877: ** is an [IN operator] that can be processed all at once. ^In other words,
9878: ** sqlite3_vtab_in() with -1 in the third argument is a mechanism
9879: ** by which the virtual table can ask SQLite if all-at-once processing
9880: ** of the IN operator is even possible.
9881: **
9882: ** <li><p>
9883: ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
9884: ** to SQLite that the virtual table does or does not want to process
9885: ** the IN operator all-at-once, respectively. ^Thus when the third
9886: ** parameter (F) is non-negative, this interface is the mechanism by
9887: ** which the virtual table tells SQLite how it wants to process the
9888: ** IN operator.
9889: ** </ol>
9890: **
9891: ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
9892: ** within the same xBestIndex method call. ^For any given P,N pair,
9893: ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
9894: ** within the same xBestIndex call. ^If the interface returns true
9895: ** (non-zero), that means that the constraint is an IN operator
9896: ** that can be processed all-at-once. ^If the constraint is not an IN
9897: ** operator or cannot be processed all-at-once, then the interface returns
9898: ** false.
9899: **
9900: ** ^(All-at-once processing of the IN operator is selected if both of the
9901: ** following conditions are met:
9902: **
9903: ** <ol>
9904: ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
9905: ** integer. This is how the virtual table tells SQLite that it wants to
9906: ** use the N-th constraint.
9907: **
9908: ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
9909: ** non-negative had F>=1.
9910: ** </ol>)^
9911: **
9912: ** ^If either or both of the conditions above are false, then SQLite uses
9913: ** the traditional one-at-a-time processing strategy for the IN constraint.
9914: ** ^If both conditions are true, then the argvIndex-th parameter to the
9915: ** xFilter method will be an [sqlite3_value] that appears to be NULL,
9916: ** but which can be passed to [sqlite3_vtab_in_first()] and
9917: ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
9918: ** of the IN constraint.
9919: */
9920: SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
9921:
9922: /*
9923: ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
9924: **
9925: ** These interfaces are only useful from within the
9926: ** [xFilter|xFilter() method] of a [virtual table] implementation.
9927: ** The result of invoking these interfaces from any other context
9928: ** is undefined and probably harmful.
9929: **
9930: ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
9931: ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
9932: ** xFilter method which invokes these routines, and specifically
9933: ** a parameter that was previously selected for all-at-once IN constraint
9934: ** processing use the [sqlite3_vtab_in()] interface in the
9935: ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
9936: ** an xFilter argument that was selected for all-at-once IN constraint
9937: ** processing, then these routines return [SQLITE_ERROR].)^
9938: **
9939: ** ^(Use these routines to access all values on the right-hand side
9940: ** of the IN constraint using code like the following:
9941: **
9942: ** <blockquote><pre>
9943: ** for(rc=sqlite3_vtab_in_first(pList, &pVal);
9944: ** rc==SQLITE_OK && pVal;
9945: ** rc=sqlite3_vtab_in_next(pList, &pVal)
9946: ** ){
9947: ** // do something with pVal
9948: ** }
9949: ** if( rc!=SQLITE_OK ){
9950: ** // an error has occurred
9951: ** }
9952: ** </pre></blockquote>)^
9953: **
9954: ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
9955: ** routines return SQLITE_OK and set *P to point to the first or next value
9956: ** on the RHS of the IN constraint. ^If there are no more values on the
9957: ** right hand side of the IN constraint, then *P is set to NULL and these
9958: ** routines return [SQLITE_DONE]. ^The return value might be
9959: ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
9960: **
9961: ** The *ppOut values returned by these routines are only valid until the
9962: ** next call to either of these routines or until the end of the xFilter
9963: ** method from which these routines were called. If the virtual table
9964: ** implementation needs to retain the *ppOut values for longer, it must make
9965: ** copies. The *ppOut values are [protected sqlite3_value|protected].
9966: */
9967: SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
9968: SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
9969:
9970: /*
9971: ** CAPI3REF: Constraint values in xBestIndex()
9972: ** METHOD: sqlite3_index_info
9973: **
9974: ** This API may only be used from within the [xBestIndex|xBestIndex method]
9975: ** of a [virtual table] implementation. The result of calling this interface
9976: ** from outside of an xBestIndex method are undefined and probably harmful.
9977: **
9978: ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
9979: ** the [xBestIndex] method of a [virtual table] implementation, with P being
9980: ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
9981: ** J being a 0-based index into P->aConstraint[], then this routine
9982: ** attempts to set *V to the value of the right-hand operand of
9983: ** that constraint if the right-hand operand is known. ^If the
9984: ** right-hand operand is not known, then *V is set to a NULL pointer.
9985: ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
9986: ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
9987: ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
9988: ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
9989: ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
9990: ** something goes wrong.
9991: **
9992: ** The sqlite3_vtab_rhs_value() interface is usually only successful if
9993: ** the right-hand operand of a constraint is a literal value in the original
9994: ** SQL statement. If the right-hand operand is an expression or a reference
9995: ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
9996: ** will probably return [SQLITE_NOTFOUND].
9997: **
9998: ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
9999: ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10000: ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10001: **
10002: ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10003: ** and remains valid for the duration of the xBestIndex method call.
10004: ** ^When xBestIndex returns, the sqlite3_value object returned by
10005: ** sqlite3_vtab_rhs_value() is automatically deallocated.
10006: **
10007: ** The "_rhs_" in the name of this routine is an abbreviation for
10008: ** "Right-Hand Side".
10009: */
10010: SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10011:
10012: /*
10013: ** CAPI3REF: Conflict resolution modes
10014: ** KEYWORDS: {conflict resolution mode}
10015: **
10016: ** These constants are returned by [sqlite3_vtab_on_conflict()] to
10017: ** inform a [virtual table] implementation what the [ON CONFLICT] mode
10018: ** is for the SQL statement being evaluated.
10019: **
10020: ** Note that the [SQLITE_IGNORE] constant is also used as a potential
10021: ** return value from the [sqlite3_set_authorizer()] callback and that
10022: ** [SQLITE_ABORT] is also a [result code].
10023: */
10024: #define SQLITE_ROLLBACK 1
10025: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10026: #define SQLITE_FAIL 3
10027: /* #define SQLITE_ABORT 4 // Also an error code */
10028: #define SQLITE_REPLACE 5
10029:
10030: /*
10031: ** CAPI3REF: Prepared Statement Scan Status Opcodes
10032: ** KEYWORDS: {scanstatus options}
10033: **
10034: ** The following constants can be used for the T parameter to the
10035: ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10036: ** different metric for sqlite3_stmt_scanstatus() to return.
10037: **
10038: ** When the value returned to V is a string, space to hold that string is
10039: ** managed by the prepared statement S and will be automatically freed when
10040: ** S is finalized.
10041: **
10042: ** Not all values are available for all query elements. When a value is
10043: ** not available, the output variable is set to -1 if the value is numeric,
10044: ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10045: **
10046: ** <dl>
10047: ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10048: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10049: ** set to the total number of times that the X-th loop has run.</dd>
10050: **
10051: ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10052: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10053: ** to the total number of rows examined by all iterations of the X-th loop.</dd>
10054: **
10055: ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10056: ** <dd>^The "double" variable pointed to by the V parameter will be set to the
10057: ** query planner's estimate for the average number of rows output from each
10058: ** iteration of the X-th loop. If the query planner's estimates was accurate,
10059: ** then this value will approximate the quotient NVISIT/NLOOP and the
10060: ** product of this value for all prior loops with the same SELECTID will
10061: ** be the NLOOP value for the current loop.
10062: **
10063: ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10064: ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10065: ** to a zero-terminated UTF-8 string containing the name of the index or table
10066: ** used for the X-th loop.
10067: **
10068: ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10069: ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10070: ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10071: ** description for the X-th loop.
10072: **
10073: ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10074: ** <dd>^The "int" variable pointed to by the V parameter will be set to the
10075: ** id for the X-th query plan element. The id value is unique within the
10076: ** statement. The select-id is the same value as is output in the first
10077: ** column of an [EXPLAIN QUERY PLAN] query.
10078: **
10079: ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10080: ** <dd>The "int" variable pointed to by the V parameter will be set to the
10081: ** the id of the parent of the current query element, if applicable, or
10082: ** to zero if the query element has no parent. This is the same value as
10083: ** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10084: **
10085: ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10086: ** <dd>The sqlite3_int64 output value is set to the number of cycles,
10087: ** according to the processor time-stamp counter, that elapsed while the
10088: ** query element was being processed. This value is not available for
10089: ** all query elements - if it is unavailable the output variable is
10090: ** set to -1.
10091: ** </dl>
10092: */
10093: #define SQLITE_SCANSTAT_NLOOP 0
10094: #define SQLITE_SCANSTAT_NVISIT 1
10095: #define SQLITE_SCANSTAT_EST 2
10096: #define SQLITE_SCANSTAT_NAME 3
10097: #define SQLITE_SCANSTAT_EXPLAIN 4
10098: #define SQLITE_SCANSTAT_SELECTID 5
10099: #define SQLITE_SCANSTAT_PARENTID 6
10100: #define SQLITE_SCANSTAT_NCYCLE 7
10101:
10102: /*
10103: ** CAPI3REF: Prepared Statement Scan Status
10104: ** METHOD: sqlite3_stmt
10105: **
10106: ** These interfaces return information about the predicted and measured
10107: ** performance for pStmt. Advanced applications can use this
10108: ** interface to compare the predicted and the measured performance and
10109: ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10110: **
10111: ** Since this interface is expected to be rarely used, it is only
10112: ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10113: ** compile-time option.
10114: **
10115: ** The "iScanStatusOp" parameter determines which status information to return.
10116: ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10117: ** of this interface is undefined. ^The requested measurement is written into
10118: ** a variable pointed to by the "pOut" parameter.
10119: **
10120: ** The "flags" parameter must be passed a mask of flags. At present only
10121: ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10122: ** is specified, then status information is available for all elements
10123: ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10124: ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10125: ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10126: ** the EXPLAIN QUERY PLAN output) are available. Invoking API
10127: ** sqlite3_stmt_scanstatus() is equivalent to calling
10128: ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10129: **
10130: ** Parameter "idx" identifies the specific query element to retrieve statistics
10131: ** for. Query elements are numbered starting from zero. A value of -1 may be
10132: ** to query for statistics regarding the entire query. ^If idx is out of range
10133: ** - less than -1 or greater than or equal to the total number of query
10134: ** elements used to implement the statement - a non-zero value is returned and
10135: ** the variable that pOut points to is unchanged.
10136: **
10137: ** See also: [sqlite3_stmt_scanstatus_reset()]
10138: */
10139: SQLITE_API int sqlite3_stmt_scanstatus(
10140: sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10141: int idx, /* Index of loop to report on */
10142: int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10143: void *pOut /* Result written here */
10144: );
10145: SQLITE_API int sqlite3_stmt_scanstatus_v2(
10146: sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10147: int idx, /* Index of loop to report on */
10148: int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10149: int flags, /* Mask of flags defined below */
10150: void *pOut /* Result written here */
10151: );
10152:
10153: /*
10154: ** CAPI3REF: Prepared Statement Scan Status
10155: ** KEYWORDS: {scan status flags}
10156: */
10157: #define SQLITE_SCANSTAT_COMPLEX 0x0001
10158:
10159: /*
10160: ** CAPI3REF: Zero Scan-Status Counters
10161: ** METHOD: sqlite3_stmt
10162: **
10163: ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10164: **
10165: ** This API is only available if the library is built with pre-processor
10166: ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10167: */
10168: SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10169:
10170: /*
10171: ** CAPI3REF: Flush caches to disk mid-transaction
10172: ** METHOD: sqlite3
10173: **
10174: ** ^If a write-transaction is open on [database connection] D when the
10175: ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
10176: ** pages in the pager-cache that are not currently in use are written out
10177: ** to disk. A dirty page may be in use if a database cursor created by an
10178: ** active SQL statement is reading from it, or if it is page 1 of a database
10179: ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10180: ** interface flushes caches for all schemas - "main", "temp", and
10181: ** any [attached] databases.
10182: **
10183: ** ^If this function needs to obtain extra database locks before dirty pages
10184: ** can be flushed to disk, it does so. ^If those locks cannot be obtained
10185: ** immediately and there is a busy-handler callback configured, it is invoked
10186: ** in the usual manner. ^If the required lock still cannot be obtained, then
10187: ** the database is skipped and an attempt made to flush any dirty pages
10188: ** belonging to the next (if any) database. ^If any databases are skipped
10189: ** because locks cannot be obtained, but no other error occurs, this
10190: ** function returns SQLITE_BUSY.
10191: **
10192: ** ^If any other error occurs while flushing dirty pages to disk (for
10193: ** example an IO error or out-of-memory condition), then processing is
10194: ** abandoned and an SQLite [error code] is returned to the caller immediately.
10195: **
10196: ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10197: **
10198: ** ^This function does not set the database handle error code or message
10199: ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10200: */
10201: SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10202:
10203: /*
10204: ** CAPI3REF: The pre-update hook.
10205: ** METHOD: sqlite3
10206: **
10207: ** ^These interfaces are only available if SQLite is compiled using the
10208: ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10209: **
10210: ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10211: ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10212: ** on a database table.
10213: ** ^At most one preupdate hook may be registered at a time on a single
10214: ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10215: ** the previous setting.
10216: ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10217: ** with a NULL pointer as the second parameter.
10218: ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10219: ** the first parameter to callbacks.
10220: **
10221: ** ^The preupdate hook only fires for changes to real database tables; the
10222: ** preupdate hook is not invoked for changes to [virtual tables] or to
10223: ** system tables like sqlite_sequence or sqlite_stat1.
10224: **
10225: ** ^The second parameter to the preupdate callback is a pointer to
10226: ** the [database connection] that registered the preupdate hook.
10227: ** ^The third parameter to the preupdate callback is one of the constants
10228: ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10229: ** kind of update operation that is about to occur.
10230: ** ^(The fourth parameter to the preupdate callback is the name of the
10231: ** database within the database connection that is being modified. This
10232: ** will be "main" for the main database or "temp" for TEMP tables or
10233: ** the name given after the AS keyword in the [ATTACH] statement for attached
10234: ** databases.)^
10235: ** ^The fifth parameter to the preupdate callback is the name of the
10236: ** table that is being modified.
10237: **
10238: ** For an UPDATE or DELETE operation on a [rowid table], the sixth
10239: ** parameter passed to the preupdate callback is the initial [rowid] of the
10240: ** row being modified or deleted. For an INSERT operation on a rowid table,
10241: ** or any operation on a WITHOUT ROWID table, the value of the sixth
10242: ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10243: ** seventh parameter is the final rowid value of the row being inserted
10244: ** or updated. The value of the seventh parameter passed to the callback
10245: ** function is not defined for operations on WITHOUT ROWID tables, or for
10246: ** DELETE operations on rowid tables.
10247: **
10248: ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10249: ** the previous call on the same [database connection] D, or NULL for
10250: ** the first call on D.
10251: **
10252: ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10253: ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10254: ** provide additional information about a preupdate event. These routines
10255: ** may only be called from within a preupdate callback. Invoking any of
10256: ** these routines from outside of a preupdate callback or with a
10257: ** [database connection] pointer that is different from the one supplied
10258: ** to the preupdate callback results in undefined and probably undesirable
10259: ** behavior.
10260: **
10261: ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10262: ** in the row that is being inserted, updated, or deleted.
10263: **
10264: ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10265: ** a [protected sqlite3_value] that contains the value of the Nth column of
10266: ** the table row before it is updated. The N parameter must be between 0
10267: ** and one less than the number of columns or the behavior will be
10268: ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10269: ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10270: ** behavior is undefined. The [sqlite3_value] that P points to
10271: ** will be destroyed when the preupdate callback returns.
10272: **
10273: ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10274: ** a [protected sqlite3_value] that contains the value of the Nth column of
10275: ** the table row after it is updated. The N parameter must be between 0
10276: ** and one less than the number of columns or the behavior will be
10277: ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10278: ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10279: ** behavior is undefined. The [sqlite3_value] that P points to
10280: ** will be destroyed when the preupdate callback returns.
10281: **
10282: ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10283: ** callback was invoked as a result of a direct insert, update, or delete
10284: ** operation; or 1 for inserts, updates, or deletes invoked by top-level
10285: ** triggers; or 2 for changes resulting from triggers called by top-level
10286: ** triggers; and so forth.
10287: **
10288: ** When the [sqlite3_blob_write()] API is used to update a blob column,
10289: ** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10290: ** in this case the new values are not available. In this case, when a
10291: ** callback made with op==SQLITE_DELETE is actually a write using the
10292: ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10293: ** the index of the column being written. In other cases, where the
10294: ** pre-update hook is being invoked for some other reason, including a
10295: ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10296: **
10297: ** See also: [sqlite3_update_hook()]
10298: */
10299: #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10300: SQLITE_API void *sqlite3_preupdate_hook(
10301: sqlite3 *db,
10302: void(*xPreUpdate)(
10303: void *pCtx, /* Copy of third arg to preupdate_hook() */
10304: sqlite3 *db, /* Database handle */
10305: int op, /* SQLITE_UPDATE, DELETE or INSERT */
10306: char const *zDb, /* Database name */
10307: char const *zName, /* Table name */
10308: sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10309: sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10310: ),
10311: void*
10312: );
10313: SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10314: SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10315: SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10316: SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10317: SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10318: #endif
10319:
10320: /*
10321: ** CAPI3REF: Low-level system error code
10322: ** METHOD: sqlite3
10323: **
10324: ** ^Attempt to return the underlying operating system error code or error
10325: ** number that caused the most recent I/O error or failure to open a file.
10326: ** The return value is OS-dependent. For example, on unix systems, after
10327: ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10328: ** called to get back the underlying "errno" that caused the problem, such
10329: ** as ENOSPC, EAUTH, EISDIR, and so forth.
10330: */
10331: SQLITE_API int sqlite3_system_errno(sqlite3*);
10332:
10333: /*
10334: ** CAPI3REF: Database Snapshot
10335: ** KEYWORDS: {snapshot} {sqlite3_snapshot}
10336: **
10337: ** An instance of the snapshot object records the state of a [WAL mode]
10338: ** database for some specific point in history.
10339: **
10340: ** In [WAL mode], multiple [database connections] that are open on the
10341: ** same database file can each be reading a different historical version
10342: ** of the database file. When a [database connection] begins a read
10343: ** transaction, that connection sees an unchanging copy of the database
10344: ** as it existed for the point in time when the transaction first started.
10345: ** Subsequent changes to the database from other connections are not seen
10346: ** by the reader until a new read transaction is started.
10347: **
10348: ** The sqlite3_snapshot object records state information about an historical
10349: ** version of the database file so that it is possible to later open a new read
10350: ** transaction that sees that historical version of the database rather than
10351: ** the most recent version.
10352: */
10353: typedef struct sqlite3_snapshot {
10354: unsigned char hidden[48];
10355: } sqlite3_snapshot;
10356:
10357: /*
10358: ** CAPI3REF: Record A Database Snapshot
10359: ** CONSTRUCTOR: sqlite3_snapshot
10360: **
10361: ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10362: ** new [sqlite3_snapshot] object that records the current state of
10363: ** schema S in database connection D. ^On success, the
10364: ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10365: ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10366: ** If there is not already a read-transaction open on schema S when
10367: ** this function is called, one is opened automatically.
10368: **
10369: ** The following must be true for this function to succeed. If any of
10370: ** the following statements are false when sqlite3_snapshot_get() is
10371: ** called, SQLITE_ERROR is returned. The final value of *P is undefined
10372: ** in this case.
10373: **
10374: ** <ul>
10375: ** <li> The database handle must not be in [autocommit mode].
10376: **
10377: ** <li> Schema S of [database connection] D must be a [WAL mode] database.
10378: **
10379: ** <li> There must not be a write transaction open on schema S of database
10380: ** connection D.
10381: **
10382: ** <li> One or more transactions must have been written to the current wal
10383: ** file since it was created on disk (by any connection). This means
10384: ** that a snapshot cannot be taken on a wal mode database with no wal
10385: ** file immediately after it is first opened. At least one transaction
10386: ** must be written to it first.
10387: ** </ul>
10388: **
10389: ** This function may also return SQLITE_NOMEM. If it is called with the
10390: ** database handle in autocommit mode but fails for some other reason,
10391: ** whether or not a read transaction is opened on schema S is undefined.
10392: **
10393: ** The [sqlite3_snapshot] object returned from a successful call to
10394: ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10395: ** to avoid a memory leak.
10396: **
10397: ** The [sqlite3_snapshot_get()] interface is only available when the
10398: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10399: */
10400: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10401: sqlite3 *db,
10402: const char *zSchema,
10403: sqlite3_snapshot **ppSnapshot
10404: );
10405:
10406: /*
10407: ** CAPI3REF: Start a read transaction on an historical snapshot
10408: ** METHOD: sqlite3_snapshot
10409: **
10410: ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10411: ** transaction or upgrades an existing one for schema S of
10412: ** [database connection] D such that the read transaction refers to
10413: ** historical [snapshot] P, rather than the most recent change to the
10414: ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10415: ** on success or an appropriate [error code] if it fails.
10416: **
10417: ** ^In order to succeed, the database connection must not be in
10418: ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10419: ** is already a read transaction open on schema S, then the database handle
10420: ** must have no active statements (SELECT statements that have been passed
10421: ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10422: ** SQLITE_ERROR is returned if either of these conditions is violated, or
10423: ** if schema S does not exist, or if the snapshot object is invalid.
10424: **
10425: ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10426: ** snapshot has been overwritten by a [checkpoint]. In this case
10427: ** SQLITE_ERROR_SNAPSHOT is returned.
10428: **
10429: ** If there is already a read transaction open when this function is
10430: ** invoked, then the same read transaction remains open (on the same
10431: ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10432: ** is returned. If another error code - for example SQLITE_PROTOCOL or an
10433: ** SQLITE_IOERR error code - is returned, then the final state of the
10434: ** read transaction is undefined. If SQLITE_OK is returned, then the
10435: ** read transaction is now open on database snapshot P.
10436: **
10437: ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10438: ** database connection D does not know that the database file for
10439: ** schema S is in [WAL mode]. A database connection might not know
10440: ** that the database file is in [WAL mode] if there has been no prior
10441: ** I/O on that database connection, or if the database entered [WAL mode]
10442: ** after the most recent I/O on the database connection.)^
10443: ** (Hint: Run "[PRAGMA application_id]" against a newly opened
10444: ** database connection in order to make it ready to use snapshots.)
10445: **
10446: ** The [sqlite3_snapshot_open()] interface is only available when the
10447: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10448: */
10449: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10450: sqlite3 *db,
10451: const char *zSchema,
10452: sqlite3_snapshot *pSnapshot
10453: );
10454:
10455: /*
10456: ** CAPI3REF: Destroy a snapshot
10457: ** DESTRUCTOR: sqlite3_snapshot
10458: **
10459: ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10460: ** The application must eventually free every [sqlite3_snapshot] object
10461: ** using this routine to avoid a memory leak.
10462: **
10463: ** The [sqlite3_snapshot_free()] interface is only available when the
10464: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10465: */
10466: SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10467:
10468: /*
10469: ** CAPI3REF: Compare the ages of two snapshot handles.
10470: ** METHOD: sqlite3_snapshot
10471: **
10472: ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10473: ** of two valid snapshot handles.
10474: **
10475: ** If the two snapshot handles are not associated with the same database
10476: ** file, the result of the comparison is undefined.
10477: **
10478: ** Additionally, the result of the comparison is only valid if both of the
10479: ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10480: ** last time the wal file was deleted. The wal file is deleted when the
10481: ** database is changed back to rollback mode or when the number of database
10482: ** clients drops to zero. If either snapshot handle was obtained before the
10483: ** wal file was last deleted, the value returned by this function
10484: ** is undefined.
10485: **
10486: ** Otherwise, this API returns a negative value if P1 refers to an older
10487: ** snapshot than P2, zero if the two handles refer to the same database
10488: ** snapshot, and a positive value if P1 is a newer snapshot than P2.
10489: **
10490: ** This interface is only available if SQLite is compiled with the
10491: ** [SQLITE_ENABLE_SNAPSHOT] option.
10492: */
10493: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10494: sqlite3_snapshot *p1,
10495: sqlite3_snapshot *p2
10496: );
10497:
10498: /*
10499: ** CAPI3REF: Recover snapshots from a wal file
10500: ** METHOD: sqlite3_snapshot
10501: **
10502: ** If a [WAL file] remains on disk after all database connections close
10503: ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10504: ** or because the last process to have the database opened exited without
10505: ** calling [sqlite3_close()]) and a new connection is subsequently opened
10506: ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10507: ** will only be able to open the last transaction added to the WAL file
10508: ** even though the WAL file contains other valid transactions.
10509: **
10510: ** This function attempts to scan the WAL file associated with database zDb
10511: ** of database handle db and make all valid snapshots available to
10512: ** sqlite3_snapshot_open(). It is an error if there is already a read
10513: ** transaction open on the database, or if the database is not a WAL mode
10514: ** database.
10515: **
10516: ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10517: **
10518: ** This interface is only available if SQLite is compiled with the
10519: ** [SQLITE_ENABLE_SNAPSHOT] option.
10520: */
10521: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10522:
10523: /*
10524: ** CAPI3REF: Serialize a database
10525: **
10526: ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10527: ** that is a serialization of the S database on [database connection] D.
10528: ** If P is not a NULL pointer, then the size of the database in bytes
10529: ** is written into *P.
10530: **
10531: ** For an ordinary on-disk database file, the serialization is just a
10532: ** copy of the disk file. For an in-memory database or a "TEMP" database,
10533: ** the serialization is the same sequence of bytes which would be written
10534: ** to disk if that database where backed up to disk.
10535: **
10536: ** The usual case is that sqlite3_serialize() copies the serialization of
10537: ** the database into memory obtained from [sqlite3_malloc64()] and returns
10538: ** a pointer to that memory. The caller is responsible for freeing the
10539: ** returned value to avoid a memory leak. However, if the F argument
10540: ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10541: ** are made, and the sqlite3_serialize() function will return a pointer
10542: ** to the contiguous memory representation of the database that SQLite
10543: ** is currently using for that database, or NULL if the no such contiguous
10544: ** memory representation of the database exists. A contiguous memory
10545: ** representation of the database will usually only exist if there has
10546: ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10547: ** values of D and S.
10548: ** The size of the database is written into *P even if the
10549: ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10550: ** of the database exists.
10551: **
10552: ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10553: ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10554: ** allocation error occurs.
10555: **
10556: ** This interface is omitted if SQLite is compiled with the
10557: ** [SQLITE_OMIT_DESERIALIZE] option.
10558: */
10559: SQLITE_API unsigned char *sqlite3_serialize(
10560: sqlite3 *db, /* The database connection */
10561: const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10562: sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10563: unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10564: );
10565:
10566: /*
10567: ** CAPI3REF: Flags for sqlite3_serialize
10568: **
10569: ** Zero or more of the following constants can be OR-ed together for
10570: ** the F argument to [sqlite3_serialize(D,S,P,F)].
10571: **
10572: ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10573: ** a pointer to contiguous in-memory database that it is currently using,
10574: ** without making a copy of the database. If SQLite is not currently using
10575: ** a contiguous in-memory database, then this option causes
10576: ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10577: ** using a contiguous in-memory database if it has been initialized by a
10578: ** prior call to [sqlite3_deserialize()].
10579: */
10580: #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10581:
10582: /*
10583: ** CAPI3REF: Deserialize a database
10584: **
10585: ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10586: ** [database connection] D to disconnect from database S and then
10587: ** reopen S as an in-memory database based on the serialization contained
10588: ** in P. The serialized database P is N bytes in size. M is the size of
10589: ** the buffer P, which might be larger than N. If M is larger than N, and
10590: ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10591: ** permitted to add content to the in-memory database as long as the total
10592: ** size does not exceed M bytes.
10593: **
10594: ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10595: ** invoke sqlite3_free() on the serialization buffer when the database
10596: ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10597: ** SQLite will try to increase the buffer size using sqlite3_realloc64()
10598: ** if writes on the database cause it to grow larger than M bytes.
10599: **
10600: ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10601: ** database is currently in a read transaction or is involved in a backup
10602: ** operation.
10603: **
10604: ** It is not possible to deserialized into the TEMP database. If the
10605: ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10606: ** function returns SQLITE_ERROR.
10607: **
10608: ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10609: ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10610: ** [sqlite3_free()] is invoked on argument P prior to returning.
10611: **
10612: ** This interface is omitted if SQLite is compiled with the
10613: ** [SQLITE_OMIT_DESERIALIZE] option.
10614: */
10615: SQLITE_API int sqlite3_deserialize(
10616: sqlite3 *db, /* The database connection */
10617: const char *zSchema, /* Which DB to reopen with the deserialization */
10618: unsigned char *pData, /* The serialized database content */
10619: sqlite3_int64 szDb, /* Number bytes in the deserialization */
10620: sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10621: unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10622: );
10623:
10624: /*
10625: ** CAPI3REF: Flags for sqlite3_deserialize()
10626: **
10627: ** The following are allowed values for 6th argument (the F argument) to
10628: ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10629: **
10630: ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10631: ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10632: ** and that SQLite should take ownership of this memory and automatically
10633: ** free it when it has finished using it. Without this flag, the caller
10634: ** is responsible for freeing any dynamically allocated memory.
10635: **
10636: ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10637: ** grow the size of the database using calls to [sqlite3_realloc64()]. This
10638: ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10639: ** Without this flag, the deserialized database cannot increase in size beyond
10640: ** the number of bytes specified by the M parameter.
10641: **
10642: ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10643: ** should be treated as read-only.
10644: */
10645: #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10646: #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10647: #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10648:
10649: /*
10650: ** Undo the hack that converts floating point types to integer for
10651: ** builds on processors without floating point support.
10652: */
10653: #ifdef SQLITE_OMIT_FLOATING_POINT
10654: # undef double
10655: #endif
10656:
10657: #if defined(__wasi__)
10658: # undef SQLITE_WASI
10659: # define SQLITE_WASI 1
10660: # undef SQLITE_OMIT_WAL
10661: # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */
10662: # ifndef SQLITE_OMIT_LOAD_EXTENSION
10663: # define SQLITE_OMIT_LOAD_EXTENSION
10664: # endif
10665: # ifndef SQLITE_THREADSAFE
10666: # define SQLITE_THREADSAFE 0
10667: # endif
10668: #endif
10669:
10670: #ifdef __cplusplus
10671: } /* End of the 'extern "C"' block */
10672: #endif
10673: #endif /* SQLITE3_H */
10674:
10675: /******** Begin file sqlite3rtree.h *********/
10676: /*
10677: ** 2010 August 30
10678: **
10679: ** The author disclaims copyright to this source code. In place of
10680: ** a legal notice, here is a blessing:
10681: **
10682: ** May you do good and not evil.
10683: ** May you find forgiveness for yourself and forgive others.
10684: ** May you share freely, never taking more than you give.
10685: **
10686: *************************************************************************
10687: */
10688:
10689: #ifndef _SQLITE3RTREE_H_
10690: #define _SQLITE3RTREE_H_
10691:
10692:
10693: #ifdef __cplusplus
10694: extern "C" {
10695: #endif
10696:
10697: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10698: typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10699:
10700: /* The double-precision datatype used by RTree depends on the
10701: ** SQLITE_RTREE_INT_ONLY compile-time option.
10702: */
10703: #ifdef SQLITE_RTREE_INT_ONLY
10704: typedef sqlite3_int64 sqlite3_rtree_dbl;
10705: #else
10706: typedef double sqlite3_rtree_dbl;
10707: #endif
10708:
10709: /*
10710: ** Register a geometry callback named zGeom that can be used as part of an
10711: ** R-Tree geometry query as follows:
10712: **
10713: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10714: */
10715: SQLITE_API int sqlite3_rtree_geometry_callback(
10716: sqlite3 *db,
10717: const char *zGeom,
10718: int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10719: void *pContext
10720: );
10721:
10722:
10723: /*
10724: ** A pointer to a structure of the following type is passed as the first
10725: ** argument to callbacks registered using rtree_geometry_callback().
10726: */
10727: struct sqlite3_rtree_geometry {
10728: void *pContext; /* Copy of pContext passed to s_r_g_c() */
10729: int nParam; /* Size of array aParam[] */
10730: sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10731: void *pUser; /* Callback implementation user data */
10732: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10733: };
10734:
10735: /*
10736: ** Register a 2nd-generation geometry callback named zScore that can be
10737: ** used as part of an R-Tree geometry query as follows:
10738: **
10739: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10740: */
10741: SQLITE_API int sqlite3_rtree_query_callback(
10742: sqlite3 *db,
10743: const char *zQueryFunc,
10744: int (*xQueryFunc)(sqlite3_rtree_query_info*),
10745: void *pContext,
10746: void (*xDestructor)(void*)
10747: );
10748:
10749:
10750: /*
10751: ** A pointer to a structure of the following type is passed as the
10752: ** argument to scored geometry callback registered using
10753: ** sqlite3_rtree_query_callback().
10754: **
10755: ** Note that the first 5 fields of this structure are identical to
10756: ** sqlite3_rtree_geometry. This structure is a subclass of
10757: ** sqlite3_rtree_geometry.
10758: */
10759: struct sqlite3_rtree_query_info {
10760: void *pContext; /* pContext from when function registered */
10761: int nParam; /* Number of function parameters */
10762: sqlite3_rtree_dbl *aParam; /* value of function parameters */
10763: void *pUser; /* callback can use this, if desired */
10764: void (*xDelUser)(void*); /* function to free pUser */
10765: sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10766: unsigned int *anQueue; /* Number of pending entries in the queue */
10767: int nCoord; /* Number of coordinates */
10768: int iLevel; /* Level of current node or entry */
10769: int mxLevel; /* The largest iLevel value in the tree */
10770: sqlite3_int64 iRowid; /* Rowid for current entry */
10771: sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10772: int eParentWithin; /* Visibility of parent node */
10773: int eWithin; /* OUT: Visibility */
10774: sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10775: /* The following fields are only available in 3.8.11 and later */
10776: sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10777: };
10778:
10779: /*
10780: ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10781: */
10782: #define NOT_WITHIN 0 /* Object completely outside of query region */
10783: #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10784: #define FULLY_WITHIN 2 /* Object fully contained within query region */
10785:
10786:
10787: #ifdef __cplusplus
10788: } /* end of the 'extern "C"' block */
10789: #endif
10790:
10791: #endif /* ifndef _SQLITE3RTREE_H_ */
10792:
10793: /******** End of sqlite3rtree.h *********/
10794: /******** Begin file sqlite3session.h *********/
10795:
10796: #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10797: #define __SQLITESESSION_H_ 1
10798:
10799: /*
10800: ** Make sure we can call this stuff from C++.
10801: */
10802: #ifdef __cplusplus
10803: extern "C" {
10804: #endif
10805:
10806:
10807: /*
10808: ** CAPI3REF: Session Object Handle
10809: **
10810: ** An instance of this object is a [session] that can be used to
10811: ** record changes to a database.
10812: */
10813: typedef struct sqlite3_session sqlite3_session;
10814:
10815: /*
10816: ** CAPI3REF: Changeset Iterator Handle
10817: **
10818: ** An instance of this object acts as a cursor for iterating
10819: ** over the elements of a [changeset] or [patchset].
10820: */
10821: typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10822:
10823: /*
10824: ** CAPI3REF: Create A New Session Object
10825: ** CONSTRUCTOR: sqlite3_session
10826: **
10827: ** Create a new session object attached to database handle db. If successful,
10828: ** a pointer to the new object is written to *ppSession and SQLITE_OK is
10829: ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10830: ** error code (e.g. SQLITE_NOMEM) is returned.
10831: **
10832: ** It is possible to create multiple session objects attached to a single
10833: ** database handle.
10834: **
10835: ** Session objects created using this function should be deleted using the
10836: ** [sqlite3session_delete()] function before the database handle that they
10837: ** are attached to is itself closed. If the database handle is closed before
10838: ** the session object is deleted, then the results of calling any session
10839: ** module function, including [sqlite3session_delete()] on the session object
10840: ** are undefined.
10841: **
10842: ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10843: ** is not possible for an application to register a pre-update hook on a
10844: ** database handle that has one or more session objects attached. Nor is
10845: ** it possible to create a session object attached to a database handle for
10846: ** which a pre-update hook is already defined. The results of attempting
10847: ** either of these things are undefined.
10848: **
10849: ** The session object will be used to create changesets for tables in
10850: ** database zDb, where zDb is either "main", or "temp", or the name of an
10851: ** attached database. It is not an error if database zDb is not attached
10852: ** to the database when the session object is created.
10853: */
10854: SQLITE_API int sqlite3session_create(
10855: sqlite3 *db, /* Database handle */
10856: const char *zDb, /* Name of db (e.g. "main") */
10857: sqlite3_session **ppSession /* OUT: New session object */
10858: );
10859:
10860: /*
10861: ** CAPI3REF: Delete A Session Object
10862: ** DESTRUCTOR: sqlite3_session
10863: **
10864: ** Delete a session object previously allocated using
10865: ** [sqlite3session_create()]. Once a session object has been deleted, the
10866: ** results of attempting to use pSession with any other session module
10867: ** function are undefined.
10868: **
10869: ** Session objects must be deleted before the database handle to which they
10870: ** are attached is closed. Refer to the documentation for
10871: ** [sqlite3session_create()] for details.
10872: */
10873: SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10874:
10875: /*
10876: ** CAPI3REF: Configure a Session Object
10877: ** METHOD: sqlite3_session
10878: **
10879: ** This method is used to configure a session object after it has been
10880: ** created. At present the only valid values for the second parameter are
10881: ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
10882: **
10883: */
10884: SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10885:
10886: /*
10887: ** CAPI3REF: Options for sqlite3session_object_config
10888: **
10889: ** The following values may passed as the the 2nd parameter to
10890: ** sqlite3session_object_config().
10891: **
10892: ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10893: ** This option is used to set, clear or query the flag that enables
10894: ** the [sqlite3session_changeset_size()] API. Because it imposes some
10895: ** computational overhead, this API is disabled by default. Argument
10896: ** pArg must point to a value of type (int). If the value is initially
10897: ** 0, then the sqlite3session_changeset_size() API is disabled. If it
10898: ** is greater than 0, then the same API is enabled. Or, if the initial
10899: ** value is less than zero, no change is made. In all cases the (int)
10900: ** variable is set to 1 if the sqlite3session_changeset_size() API is
10901: ** enabled following the current call, or 0 otherwise.
10902: **
10903: ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10904: ** the first table has been attached to the session object.
10905: **
10906: ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
10907: ** This option is used to set, clear or query the flag that enables
10908: ** collection of data for tables with no explicit PRIMARY KEY.
10909: **
10910: ** Normally, tables with no explicit PRIMARY KEY are simply ignored
10911: ** by the sessions module. However, if this flag is set, it behaves
10912: ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
10913: ** as their leftmost columns.
10914: **
10915: ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10916: ** the first table has been attached to the session object.
10917: */
10918: #define SQLITE_SESSION_OBJCONFIG_SIZE 1
10919: #define SQLITE_SESSION_OBJCONFIG_ROWID 2
10920:
10921: /*
10922: ** CAPI3REF: Enable Or Disable A Session Object
10923: ** METHOD: sqlite3_session
10924: **
10925: ** Enable or disable the recording of changes by a session object. When
10926: ** enabled, a session object records changes made to the database. When
10927: ** disabled - it does not. A newly created session object is enabled.
10928: ** Refer to the documentation for [sqlite3session_changeset()] for further
10929: ** details regarding how enabling and disabling a session object affects
10930: ** the eventual changesets.
10931: **
10932: ** Passing zero to this function disables the session. Passing a value
10933: ** greater than zero enables it. Passing a value less than zero is a
10934: ** no-op, and may be used to query the current state of the session.
10935: **
10936: ** The return value indicates the final state of the session object: 0 if
10937: ** the session is disabled, or 1 if it is enabled.
10938: */
10939: SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10940:
10941: /*
10942: ** CAPI3REF: Set Or Clear the Indirect Change Flag
10943: ** METHOD: sqlite3_session
10944: **
10945: ** Each change recorded by a session object is marked as either direct or
10946: ** indirect. A change is marked as indirect if either:
10947: **
10948: ** <ul>
10949: ** <li> The session object "indirect" flag is set when the change is
10950: ** made, or
10951: ** <li> The change is made by an SQL trigger or foreign key action
10952: ** instead of directly as a result of a users SQL statement.
10953: ** </ul>
10954: **
10955: ** If a single row is affected by more than one operation within a session,
10956: ** then the change is considered indirect if all operations meet the criteria
10957: ** for an indirect change above, or direct otherwise.
10958: **
10959: ** This function is used to set, clear or query the session object indirect
10960: ** flag. If the second argument passed to this function is zero, then the
10961: ** indirect flag is cleared. If it is greater than zero, the indirect flag
10962: ** is set. Passing a value less than zero does not modify the current value
10963: ** of the indirect flag, and may be used to query the current state of the
10964: ** indirect flag for the specified session object.
10965: **
10966: ** The return value indicates the final state of the indirect flag: 0 if
10967: ** it is clear, or 1 if it is set.
10968: */
10969: SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10970:
10971: /*
10972: ** CAPI3REF: Attach A Table To A Session Object
10973: ** METHOD: sqlite3_session
10974: **
10975: ** If argument zTab is not NULL, then it is the name of a table to attach
10976: ** to the session object passed as the first argument. All subsequent changes
10977: ** made to the table while the session object is enabled will be recorded. See
10978: ** documentation for [sqlite3session_changeset()] for further details.
10979: **
10980: ** Or, if argument zTab is NULL, then changes are recorded for all tables
10981: ** in the database. If additional tables are added to the database (by
10982: ** executing "CREATE TABLE" statements) after this call is made, changes for
10983: ** the new tables are also recorded.
10984: **
10985: ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10986: ** defined as part of their CREATE TABLE statement. It does not matter if the
10987: ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10988: ** KEY may consist of a single column, or may be a composite key.
10989: **
10990: ** It is not an error if the named table does not exist in the database. Nor
10991: ** is it an error if the named table does not have a PRIMARY KEY. However,
10992: ** no changes will be recorded in either of these scenarios.
10993: **
10994: ** Changes are not recorded for individual rows that have NULL values stored
10995: ** in one or more of their PRIMARY KEY columns.
10996: **
10997: ** SQLITE_OK is returned if the call completes without error. Or, if an error
10998: ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10999: **
11000: ** <h3>Special sqlite_stat1 Handling</h3>
11001: **
11002: ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11003: ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11004: ** <pre>
11005: ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
11006: ** </pre>
11007: **
11008: ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11009: ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11010: ** are recorded for rows for which (idx IS NULL) is true. However, for such
11011: ** rows a zero-length blob (SQL value X'') is stored in the changeset or
11012: ** patchset instead of a NULL value. This allows such changesets to be
11013: ** manipulated by legacy implementations of sqlite3changeset_invert(),
11014: ** concat() and similar.
11015: **
11016: ** The sqlite3changeset_apply() function automatically converts the
11017: ** zero-length blob back to a NULL value when updating the sqlite_stat1
11018: ** table. However, if the application calls sqlite3changeset_new(),
11019: ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11020: ** iterator directly (including on a changeset iterator passed to a
11021: ** conflict-handler callback) then the X'' value is returned. The application
11022: ** must translate X'' to NULL itself if required.
11023: **
11024: ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11025: ** changes made to the sqlite_stat1 table. Legacy versions of the
11026: ** sqlite3changeset_apply() function silently ignore any modifications to the
11027: ** sqlite_stat1 table that are part of a changeset or patchset.
11028: */
11029: SQLITE_API int sqlite3session_attach(
11030: sqlite3_session *pSession, /* Session object */
11031: const char *zTab /* Table name */
11032: );
11033:
11034: /*
11035: ** CAPI3REF: Set a table filter on a Session Object.
11036: ** METHOD: sqlite3_session
11037: **
11038: ** The second argument (xFilter) is the "filter callback". For changes to rows
11039: ** in tables that are not attached to the Session object, the filter is called
11040: ** to determine whether changes to the table's rows should be tracked or not.
11041: ** If xFilter returns 0, changes are not tracked. Note that once a table is
11042: ** attached, xFilter will not be called again.
11043: */
11044: SQLITE_API void sqlite3session_table_filter(
11045: sqlite3_session *pSession, /* Session object */
11046: int(*xFilter)(
11047: void *pCtx, /* Copy of third arg to _filter_table() */
11048: const char *zTab /* Table name */
11049: ),
11050: void *pCtx /* First argument passed to xFilter */
11051: );
11052:
11053: /*
11054: ** CAPI3REF: Generate A Changeset From A Session Object
11055: ** METHOD: sqlite3_session
11056: **
11057: ** Obtain a changeset containing changes to the tables attached to the
11058: ** session object passed as the first argument. If successful,
11059: ** set *ppChangeset to point to a buffer containing the changeset
11060: ** and *pnChangeset to the size of the changeset in bytes before returning
11061: ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11062: ** zero and return an SQLite error code.
11063: **
11064: ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11065: ** each representing a change to a single row of an attached table. An INSERT
11066: ** change contains the values of each field of a new database row. A DELETE
11067: ** contains the original values of each field of a deleted database row. An
11068: ** UPDATE change contains the original values of each field of an updated
11069: ** database row along with the updated values for each updated non-primary-key
11070: ** column. It is not possible for an UPDATE change to represent a change that
11071: ** modifies the values of primary key columns. If such a change is made, it
11072: ** is represented in a changeset as a DELETE followed by an INSERT.
11073: **
11074: ** Changes are not recorded for rows that have NULL values stored in one or
11075: ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11076: ** no corresponding change is present in the changesets returned by this
11077: ** function. If an existing row with one or more NULL values stored in
11078: ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11079: ** only an INSERT is appears in the changeset. Similarly, if an existing row
11080: ** with non-NULL PRIMARY KEY values is updated so that one or more of its
11081: ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11082: ** DELETE change only.
11083: **
11084: ** The contents of a changeset may be traversed using an iterator created
11085: ** using the [sqlite3changeset_start()] API. A changeset may be applied to
11086: ** a database with a compatible schema using the [sqlite3changeset_apply()]
11087: ** API.
11088: **
11089: ** Within a changeset generated by this function, all changes related to a
11090: ** single table are grouped together. In other words, when iterating through
11091: ** a changeset or when applying a changeset to a database, all changes related
11092: ** to a single table are processed before moving on to the next table. Tables
11093: ** are sorted in the same order in which they were attached (or auto-attached)
11094: ** to the sqlite3_session object. The order in which the changes related to
11095: ** a single table are stored is undefined.
11096: **
11097: ** Following a successful call to this function, it is the responsibility of
11098: ** the caller to eventually free the buffer that *ppChangeset points to using
11099: ** [sqlite3_free()].
11100: **
11101: ** <h3>Changeset Generation</h3>
11102: **
11103: ** Once a table has been attached to a session object, the session object
11104: ** records the primary key values of all new rows inserted into the table.
11105: ** It also records the original primary key and other column values of any
11106: ** deleted or updated rows. For each unique primary key value, data is only
11107: ** recorded once - the first time a row with said primary key is inserted,
11108: ** updated or deleted in the lifetime of the session.
11109: **
11110: ** There is one exception to the previous paragraph: when a row is inserted,
11111: ** updated or deleted, if one or more of its primary key columns contain a
11112: ** NULL value, no record of the change is made.
11113: **
11114: ** The session object therefore accumulates two types of records - those
11115: ** that consist of primary key values only (created when the user inserts
11116: ** a new record) and those that consist of the primary key values and the
11117: ** original values of other table columns (created when the users deletes
11118: ** or updates a record).
11119: **
11120: ** When this function is called, the requested changeset is created using
11121: ** both the accumulated records and the current contents of the database
11122: ** file. Specifically:
11123: **
11124: ** <ul>
11125: ** <li> For each record generated by an insert, the database is queried
11126: ** for a row with a matching primary key. If one is found, an INSERT
11127: ** change is added to the changeset. If no such row is found, no change
11128: ** is added to the changeset.
11129: **
11130: ** <li> For each record generated by an update or delete, the database is
11131: ** queried for a row with a matching primary key. If such a row is
11132: ** found and one or more of the non-primary key fields have been
11133: ** modified from their original values, an UPDATE change is added to
11134: ** the changeset. Or, if no such row is found in the table, a DELETE
11135: ** change is added to the changeset. If there is a row with a matching
11136: ** primary key in the database, but all fields contain their original
11137: ** values, no change is added to the changeset.
11138: ** </ul>
11139: **
11140: ** This means, amongst other things, that if a row is inserted and then later
11141: ** deleted while a session object is active, neither the insert nor the delete
11142: ** will be present in the changeset. Or if a row is deleted and then later a
11143: ** row with the same primary key values inserted while a session object is
11144: ** active, the resulting changeset will contain an UPDATE change instead of
11145: ** a DELETE and an INSERT.
11146: **
11147: ** When a session object is disabled (see the [sqlite3session_enable()] API),
11148: ** it does not accumulate records when rows are inserted, updated or deleted.
11149: ** This may appear to have some counter-intuitive effects if a single row
11150: ** is written to more than once during a session. For example, if a row
11151: ** is inserted while a session object is enabled, then later deleted while
11152: ** the same session object is disabled, no INSERT record will appear in the
11153: ** changeset, even though the delete took place while the session was disabled.
11154: ** Or, if one field of a row is updated while a session is disabled, and
11155: ** another field of the same row is updated while the session is enabled, the
11156: ** resulting changeset will contain an UPDATE change that updates both fields.
11157: */
11158: SQLITE_API int sqlite3session_changeset(
11159: sqlite3_session *pSession, /* Session object */
11160: int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11161: void **ppChangeset /* OUT: Buffer containing changeset */
11162: );
11163:
11164: /*
11165: ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11166: ** METHOD: sqlite3_session
11167: **
11168: ** By default, this function always returns 0. For it to return
11169: ** a useful result, the sqlite3_session object must have been configured
11170: ** to enable this API using sqlite3session_object_config() with the
11171: ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11172: **
11173: ** When enabled, this function returns an upper limit, in bytes, for the size
11174: ** of the changeset that might be produced if sqlite3session_changeset() were
11175: ** called. The final changeset size might be equal to or smaller than the
11176: ** size in bytes returned by this function.
11177: */
11178: SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11179:
11180: /*
11181: ** CAPI3REF: Load The Difference Between Tables Into A Session
11182: ** METHOD: sqlite3_session
11183: **
11184: ** If it is not already attached to the session object passed as the first
11185: ** argument, this function attaches table zTbl in the same manner as the
11186: ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11187: ** does not have a primary key, this function is a no-op (but does not return
11188: ** an error).
11189: **
11190: ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11191: ** attached to the same database handle as the session object that contains
11192: ** a table compatible with the table attached to the session by this function.
11193: ** A table is considered compatible if it:
11194: **
11195: ** <ul>
11196: ** <li> Has the same name,
11197: ** <li> Has the same set of columns declared in the same order, and
11198: ** <li> Has the same PRIMARY KEY definition.
11199: ** </ul>
11200: **
11201: ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11202: ** are compatible but do not have any PRIMARY KEY columns, it is not an error
11203: ** but no changes are added to the session object. As with other session
11204: ** APIs, tables without PRIMARY KEYs are simply ignored.
11205: **
11206: ** This function adds a set of changes to the session object that could be
11207: ** used to update the table in database zFrom (call this the "from-table")
11208: ** so that its content is the same as the table attached to the session
11209: ** object (call this the "to-table"). Specifically:
11210: **
11211: ** <ul>
11212: ** <li> For each row (primary key) that exists in the to-table but not in
11213: ** the from-table, an INSERT record is added to the session object.
11214: **
11215: ** <li> For each row (primary key) that exists in the to-table but not in
11216: ** the from-table, a DELETE record is added to the session object.
11217: **
11218: ** <li> For each row (primary key) that exists in both tables, but features
11219: ** different non-PK values in each, an UPDATE record is added to the
11220: ** session.
11221: ** </ul>
11222: **
11223: ** To clarify, if this function is called and then a changeset constructed
11224: ** using [sqlite3session_changeset()], then after applying that changeset to
11225: ** database zFrom the contents of the two compatible tables would be
11226: ** identical.
11227: **
11228: ** It an error if database zFrom does not exist or does not contain the
11229: ** required compatible table.
11230: **
11231: ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11232: ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11233: ** may be set to point to a buffer containing an English language error
11234: ** message. It is the responsibility of the caller to free this buffer using
11235: ** sqlite3_free().
11236: */
11237: SQLITE_API int sqlite3session_diff(
11238: sqlite3_session *pSession,
11239: const char *zFromDb,
11240: const char *zTbl,
11241: char **pzErrMsg
11242: );
11243:
11244:
11245: /*
11246: ** CAPI3REF: Generate A Patchset From A Session Object
11247: ** METHOD: sqlite3_session
11248: **
11249: ** The differences between a patchset and a changeset are that:
11250: **
11251: ** <ul>
11252: ** <li> DELETE records consist of the primary key fields only. The
11253: ** original values of other fields are omitted.
11254: ** <li> The original values of any modified fields are omitted from
11255: ** UPDATE records.
11256: ** </ul>
11257: **
11258: ** A patchset blob may be used with up to date versions of all
11259: ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11260: ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11261: ** attempting to use a patchset blob with old versions of the
11262: ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11263: **
11264: ** Because the non-primary key "old.*" fields are omitted, no
11265: ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11266: ** is passed to the sqlite3changeset_apply() API. Other conflict types work
11267: ** in the same way as for changesets.
11268: **
11269: ** Changes within a patchset are ordered in the same way as for changesets
11270: ** generated by the sqlite3session_changeset() function (i.e. all changes for
11271: ** a single table are grouped together, tables appear in the order in which
11272: ** they were attached to the session object).
11273: */
11274: SQLITE_API int sqlite3session_patchset(
11275: sqlite3_session *pSession, /* Session object */
11276: int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11277: void **ppPatchset /* OUT: Buffer containing patchset */
11278: );
11279:
11280: /*
11281: ** CAPI3REF: Test if a changeset has recorded any changes.
11282: **
11283: ** Return non-zero if no changes to attached tables have been recorded by
11284: ** the session object passed as the first argument. Otherwise, if one or
11285: ** more changes have been recorded, return zero.
11286: **
11287: ** Even if this function returns zero, it is possible that calling
11288: ** [sqlite3session_changeset()] on the session handle may still return a
11289: ** changeset that contains no changes. This can happen when a row in
11290: ** an attached table is modified and then later on the original values
11291: ** are restored. However, if this function returns non-zero, then it is
11292: ** guaranteed that a call to sqlite3session_changeset() will return a
11293: ** changeset containing zero changes.
11294: */
11295: SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11296:
11297: /*
11298: ** CAPI3REF: Query for the amount of heap memory used by a session object.
11299: **
11300: ** This API returns the total amount of heap memory in bytes currently
11301: ** used by the session object passed as the only argument.
11302: */
11303: SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11304:
11305: /*
11306: ** CAPI3REF: Create An Iterator To Traverse A Changeset
11307: ** CONSTRUCTOR: sqlite3_changeset_iter
11308: **
11309: ** Create an iterator used to iterate through the contents of a changeset.
11310: ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11311: ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11312: ** SQLite error code is returned.
11313: **
11314: ** The following functions can be used to advance and query a changeset
11315: ** iterator created by this function:
11316: **
11317: ** <ul>
11318: ** <li> [sqlite3changeset_next()]
11319: ** <li> [sqlite3changeset_op()]
11320: ** <li> [sqlite3changeset_new()]
11321: ** <li> [sqlite3changeset_old()]
11322: ** </ul>
11323: **
11324: ** It is the responsibility of the caller to eventually destroy the iterator
11325: ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11326: ** changeset (pChangeset) must remain valid until after the iterator is
11327: ** destroyed.
11328: **
11329: ** Assuming the changeset blob was created by one of the
11330: ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11331: ** [sqlite3changeset_invert()] functions, all changes within the changeset
11332: ** that apply to a single table are grouped together. This means that when
11333: ** an application iterates through a changeset using an iterator created by
11334: ** this function, all changes that relate to a single table are visited
11335: ** consecutively. There is no chance that the iterator will visit a change
11336: ** the applies to table X, then one for table Y, and then later on visit
11337: ** another change for table X.
11338: **
11339: ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11340: ** may be modified by passing a combination of
11341: ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11342: **
11343: ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11344: ** and therefore subject to change.
11345: */
11346: SQLITE_API int sqlite3changeset_start(
11347: sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11348: int nChangeset, /* Size of changeset blob in bytes */
11349: void *pChangeset /* Pointer to blob containing changeset */
11350: );
11351: SQLITE_API int sqlite3changeset_start_v2(
11352: sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11353: int nChangeset, /* Size of changeset blob in bytes */
11354: void *pChangeset, /* Pointer to blob containing changeset */
11355: int flags /* SESSION_CHANGESETSTART_* flags */
11356: );
11357:
11358: /*
11359: ** CAPI3REF: Flags for sqlite3changeset_start_v2
11360: **
11361: ** The following flags may passed via the 4th parameter to
11362: ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11363: **
11364: ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11365: ** Invert the changeset while iterating through it. This is equivalent to
11366: ** inverting a changeset using sqlite3changeset_invert() before applying it.
11367: ** It is an error to specify this flag with a patchset.
11368: */
11369: #define SQLITE_CHANGESETSTART_INVERT 0x0002
11370:
11371:
11372: /*
11373: ** CAPI3REF: Advance A Changeset Iterator
11374: ** METHOD: sqlite3_changeset_iter
11375: **
11376: ** This function may only be used with iterators created by the function
11377: ** [sqlite3changeset_start()]. If it is called on an iterator passed to
11378: ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11379: ** is returned and the call has no effect.
11380: **
11381: ** Immediately after an iterator is created by sqlite3changeset_start(), it
11382: ** does not point to any change in the changeset. Assuming the changeset
11383: ** is not empty, the first call to this function advances the iterator to
11384: ** point to the first change in the changeset. Each subsequent call advances
11385: ** the iterator to point to the next change in the changeset (if any). If
11386: ** no error occurs and the iterator points to a valid change after a call
11387: ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11388: ** Otherwise, if all changes in the changeset have already been visited,
11389: ** SQLITE_DONE is returned.
11390: **
11391: ** If an error occurs, an SQLite error code is returned. Possible error
11392: ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11393: ** SQLITE_NOMEM.
11394: */
11395: SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11396:
11397: /*
11398: ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11399: ** METHOD: sqlite3_changeset_iter
11400: **
11401: ** The pIter argument passed to this function may either be an iterator
11402: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11403: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11404: ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11405: ** is not the case, this function returns [SQLITE_MISUSE].
11406: **
11407: ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11408: ** outputs are set through these pointers:
11409: **
11410: ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11411: ** depending on the type of change that the iterator currently points to;
11412: **
11413: ** *pnCol is set to the number of columns in the table affected by the change; and
11414: **
11415: ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11416: ** the name of the table affected by the current change. The buffer remains
11417: ** valid until either sqlite3changeset_next() is called on the iterator
11418: ** or until the conflict-handler function returns.
11419: **
11420: ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11421: ** is an indirect change, or false (0) otherwise. See the documentation for
11422: ** [sqlite3session_indirect()] for a description of direct and indirect
11423: ** changes.
11424: **
11425: ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11426: ** SQLite error code is returned. The values of the output variables may not
11427: ** be trusted in this case.
11428: */
11429: SQLITE_API int sqlite3changeset_op(
11430: sqlite3_changeset_iter *pIter, /* Iterator object */
11431: const char **pzTab, /* OUT: Pointer to table name */
11432: int *pnCol, /* OUT: Number of columns in table */
11433: int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11434: int *pbIndirect /* OUT: True for an 'indirect' change */
11435: );
11436:
11437: /*
11438: ** CAPI3REF: Obtain The Primary Key Definition Of A Table
11439: ** METHOD: sqlite3_changeset_iter
11440: **
11441: ** For each modified table, a changeset includes the following:
11442: **
11443: ** <ul>
11444: ** <li> The number of columns in the table, and
11445: ** <li> Which of those columns make up the tables PRIMARY KEY.
11446: ** </ul>
11447: **
11448: ** This function is used to find which columns comprise the PRIMARY KEY of
11449: ** the table modified by the change that iterator pIter currently points to.
11450: ** If successful, *pabPK is set to point to an array of nCol entries, where
11451: ** nCol is the number of columns in the table. Elements of *pabPK are set to
11452: ** 0x01 if the corresponding column is part of the tables primary key, or
11453: ** 0x00 if it is not.
11454: **
11455: ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11456: ** in the table.
11457: **
11458: ** If this function is called when the iterator does not point to a valid
11459: ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11460: ** SQLITE_OK is returned and the output variables populated as described
11461: ** above.
11462: */
11463: SQLITE_API int sqlite3changeset_pk(
11464: sqlite3_changeset_iter *pIter, /* Iterator object */
11465: unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11466: int *pnCol /* OUT: Number of entries in output array */
11467: );
11468:
11469: /*
11470: ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11471: ** METHOD: sqlite3_changeset_iter
11472: **
11473: ** The pIter argument passed to this function may either be an iterator
11474: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11475: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11476: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11477: ** Furthermore, it may only be called if the type of change that the iterator
11478: ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11479: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11480: **
11481: ** Argument iVal must be greater than or equal to 0, and less than the number
11482: ** of columns in the table affected by the current change. Otherwise,
11483: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11484: **
11485: ** If successful, this function sets *ppValue to point to a protected
11486: ** sqlite3_value object containing the iVal'th value from the vector of
11487: ** original row values stored as part of the UPDATE or DELETE change and
11488: ** returns SQLITE_OK. The name of the function comes from the fact that this
11489: ** is similar to the "old.*" columns available to update or delete triggers.
11490: **
11491: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11492: ** is returned and *ppValue is set to NULL.
11493: */
11494: SQLITE_API int sqlite3changeset_old(
11495: sqlite3_changeset_iter *pIter, /* Changeset iterator */
11496: int iVal, /* Column number */
11497: sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11498: );
11499:
11500: /*
11501: ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11502: ** METHOD: sqlite3_changeset_iter
11503: **
11504: ** The pIter argument passed to this function may either be an iterator
11505: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11506: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11507: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11508: ** Furthermore, it may only be called if the type of change that the iterator
11509: ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11510: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11511: **
11512: ** Argument iVal must be greater than or equal to 0, and less than the number
11513: ** of columns in the table affected by the current change. Otherwise,
11514: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11515: **
11516: ** If successful, this function sets *ppValue to point to a protected
11517: ** sqlite3_value object containing the iVal'th value from the vector of
11518: ** new row values stored as part of the UPDATE or INSERT change and
11519: ** returns SQLITE_OK. If the change is an UPDATE and does not include
11520: ** a new value for the requested column, *ppValue is set to NULL and
11521: ** SQLITE_OK returned. The name of the function comes from the fact that
11522: ** this is similar to the "new.*" columns available to update or delete
11523: ** triggers.
11524: **
11525: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11526: ** is returned and *ppValue is set to NULL.
11527: */
11528: SQLITE_API int sqlite3changeset_new(
11529: sqlite3_changeset_iter *pIter, /* Changeset iterator */
11530: int iVal, /* Column number */
11531: sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11532: );
11533:
11534: /*
11535: ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11536: ** METHOD: sqlite3_changeset_iter
11537: **
11538: ** This function should only be used with iterator objects passed to a
11539: ** conflict-handler callback by [sqlite3changeset_apply()] with either
11540: ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11541: ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11542: ** is set to NULL.
11543: **
11544: ** Argument iVal must be greater than or equal to 0, and less than the number
11545: ** of columns in the table affected by the current change. Otherwise,
11546: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11547: **
11548: ** If successful, this function sets *ppValue to point to a protected
11549: ** sqlite3_value object containing the iVal'th value from the
11550: ** "conflicting row" associated with the current conflict-handler callback
11551: ** and returns SQLITE_OK.
11552: **
11553: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11554: ** is returned and *ppValue is set to NULL.
11555: */
11556: SQLITE_API int sqlite3changeset_conflict(
11557: sqlite3_changeset_iter *pIter, /* Changeset iterator */
11558: int iVal, /* Column number */
11559: sqlite3_value **ppValue /* OUT: Value from conflicting row */
11560: );
11561:
11562: /*
11563: ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11564: ** METHOD: sqlite3_changeset_iter
11565: **
11566: ** This function may only be called with an iterator passed to an
11567: ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11568: ** it sets the output variable to the total number of known foreign key
11569: ** violations in the destination database and returns SQLITE_OK.
11570: **
11571: ** In all other cases this function returns SQLITE_MISUSE.
11572: */
11573: SQLITE_API int sqlite3changeset_fk_conflicts(
11574: sqlite3_changeset_iter *pIter, /* Changeset iterator */
11575: int *pnOut /* OUT: Number of FK violations */
11576: );
11577:
11578:
11579: /*
11580: ** CAPI3REF: Finalize A Changeset Iterator
11581: ** METHOD: sqlite3_changeset_iter
11582: **
11583: ** This function is used to finalize an iterator allocated with
11584: ** [sqlite3changeset_start()].
11585: **
11586: ** This function should only be called on iterators created using the
11587: ** [sqlite3changeset_start()] function. If an application calls this
11588: ** function with an iterator passed to a conflict-handler by
11589: ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11590: ** call has no effect.
11591: **
11592: ** If an error was encountered within a call to an sqlite3changeset_xxx()
11593: ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11594: ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11595: ** to that error is returned by this function. Otherwise, SQLITE_OK is
11596: ** returned. This is to allow the following pattern (pseudo-code):
11597: **
11598: ** <pre>
11599: ** sqlite3changeset_start();
11600: ** while( SQLITE_ROW==sqlite3changeset_next() ){
11601: ** // Do something with change.
11602: ** }
11603: ** rc = sqlite3changeset_finalize();
11604: ** if( rc!=SQLITE_OK ){
11605: ** // An error has occurred
11606: ** }
11607: ** </pre>
11608: */
11609: SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11610:
11611: /*
11612: ** CAPI3REF: Invert A Changeset
11613: **
11614: ** This function is used to "invert" a changeset object. Applying an inverted
11615: ** changeset to a database reverses the effects of applying the uninverted
11616: ** changeset. Specifically:
11617: **
11618: ** <ul>
11619: ** <li> Each DELETE change is changed to an INSERT, and
11620: ** <li> Each INSERT change is changed to a DELETE, and
11621: ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11622: ** </ul>
11623: **
11624: ** This function does not change the order in which changes appear within
11625: ** the changeset. It merely reverses the sense of each individual change.
11626: **
11627: ** If successful, a pointer to a buffer containing the inverted changeset
11628: ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11629: ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11630: ** zeroed and an SQLite error code returned.
11631: **
11632: ** It is the responsibility of the caller to eventually call sqlite3_free()
11633: ** on the *ppOut pointer to free the buffer allocation following a successful
11634: ** call to this function.
11635: **
11636: ** WARNING/TODO: This function currently assumes that the input is a valid
11637: ** changeset. If it is not, the results are undefined.
11638: */
11639: SQLITE_API int sqlite3changeset_invert(
11640: int nIn, const void *pIn, /* Input changeset */
11641: int *pnOut, void **ppOut /* OUT: Inverse of input */
11642: );
11643:
11644: /*
11645: ** CAPI3REF: Concatenate Two Changeset Objects
11646: **
11647: ** This function is used to concatenate two changesets, A and B, into a
11648: ** single changeset. The result is a changeset equivalent to applying
11649: ** changeset A followed by changeset B.
11650: **
11651: ** This function combines the two input changesets using an
11652: ** sqlite3_changegroup object. Calling it produces similar results as the
11653: ** following code fragment:
11654: **
11655: ** <pre>
11656: ** sqlite3_changegroup *pGrp;
11657: ** rc = sqlite3_changegroup_new(&pGrp);
11658: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11659: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11660: ** if( rc==SQLITE_OK ){
11661: ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11662: ** }else{
11663: ** *ppOut = 0;
11664: ** *pnOut = 0;
11665: ** }
11666: ** </pre>
11667: **
11668: ** Refer to the sqlite3_changegroup documentation below for details.
11669: */
11670: SQLITE_API int sqlite3changeset_concat(
11671: int nA, /* Number of bytes in buffer pA */
11672: void *pA, /* Pointer to buffer containing changeset A */
11673: int nB, /* Number of bytes in buffer pB */
11674: void *pB, /* Pointer to buffer containing changeset B */
11675: int *pnOut, /* OUT: Number of bytes in output changeset */
11676: void **ppOut /* OUT: Buffer containing output changeset */
11677: );
11678:
11679:
11680: /*
11681: ** CAPI3REF: Changegroup Handle
11682: **
11683: ** A changegroup is an object used to combine two or more
11684: ** [changesets] or [patchsets]
11685: */
11686: typedef struct sqlite3_changegroup sqlite3_changegroup;
11687:
11688: /*
11689: ** CAPI3REF: Create A New Changegroup Object
11690: ** CONSTRUCTOR: sqlite3_changegroup
11691: **
11692: ** An sqlite3_changegroup object is used to combine two or more changesets
11693: ** (or patchsets) into a single changeset (or patchset). A single changegroup
11694: ** object may combine changesets or patchsets, but not both. The output is
11695: ** always in the same format as the input.
11696: **
11697: ** If successful, this function returns SQLITE_OK and populates (*pp) with
11698: ** a pointer to a new sqlite3_changegroup object before returning. The caller
11699: ** should eventually free the returned object using a call to
11700: ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11701: ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11702: **
11703: ** The usual usage pattern for an sqlite3_changegroup object is as follows:
11704: **
11705: ** <ul>
11706: ** <li> It is created using a call to sqlite3changegroup_new().
11707: **
11708: ** <li> Zero or more changesets (or patchsets) are added to the object
11709: ** by calling sqlite3changegroup_add().
11710: **
11711: ** <li> The result of combining all input changesets together is obtained
11712: ** by the application via a call to sqlite3changegroup_output().
11713: **
11714: ** <li> The object is deleted using a call to sqlite3changegroup_delete().
11715: ** </ul>
11716: **
11717: ** Any number of calls to add() and output() may be made between the calls to
11718: ** new() and delete(), and in any order.
11719: **
11720: ** As well as the regular sqlite3changegroup_add() and
11721: ** sqlite3changegroup_output() functions, also available are the streaming
11722: ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11723: */
11724: SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11725:
11726: /*
11727: ** CAPI3REF: Add A Changeset To A Changegroup
11728: ** METHOD: sqlite3_changegroup
11729: **
11730: ** Add all changes within the changeset (or patchset) in buffer pData (size
11731: ** nData bytes) to the changegroup.
11732: **
11733: ** If the buffer contains a patchset, then all prior calls to this function
11734: ** on the same changegroup object must also have specified patchsets. Or, if
11735: ** the buffer contains a changeset, so must have the earlier calls to this
11736: ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11737: ** to the changegroup.
11738: **
11739: ** Rows within the changeset and changegroup are identified by the values in
11740: ** their PRIMARY KEY columns. A change in the changeset is considered to
11741: ** apply to the same row as a change already present in the changegroup if
11742: ** the two rows have the same primary key.
11743: **
11744: ** Changes to rows that do not already appear in the changegroup are
11745: ** simply copied into it. Or, if both the new changeset and the changegroup
11746: ** contain changes that apply to a single row, the final contents of the
11747: ** changegroup depends on the type of each change, as follows:
11748: **
11749: ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11750: ** <tr><th style="white-space:pre">Existing Change </th>
11751: ** <th style="white-space:pre">New Change </th>
11752: ** <th>Output Change
11753: ** <tr><td>INSERT <td>INSERT <td>
11754: ** The new change is ignored. This case does not occur if the new
11755: ** changeset was recorded immediately after the changesets already
11756: ** added to the changegroup.
11757: ** <tr><td>INSERT <td>UPDATE <td>
11758: ** The INSERT change remains in the changegroup. The values in the
11759: ** INSERT change are modified as if the row was inserted by the
11760: ** existing change and then updated according to the new change.
11761: ** <tr><td>INSERT <td>DELETE <td>
11762: ** The existing INSERT is removed from the changegroup. The DELETE is
11763: ** not added.
11764: ** <tr><td>UPDATE <td>INSERT <td>
11765: ** The new change is ignored. This case does not occur if the new
11766: ** changeset was recorded immediately after the changesets already
11767: ** added to the changegroup.
11768: ** <tr><td>UPDATE <td>UPDATE <td>
11769: ** The existing UPDATE remains within the changegroup. It is amended
11770: ** so that the accompanying values are as if the row was updated once
11771: ** by the existing change and then again by the new change.
11772: ** <tr><td>UPDATE <td>DELETE <td>
11773: ** The existing UPDATE is replaced by the new DELETE within the
11774: ** changegroup.
11775: ** <tr><td>DELETE <td>INSERT <td>
11776: ** If one or more of the column values in the row inserted by the
11777: ** new change differ from those in the row deleted by the existing
11778: ** change, the existing DELETE is replaced by an UPDATE within the
11779: ** changegroup. Otherwise, if the inserted row is exactly the same
11780: ** as the deleted row, the existing DELETE is simply discarded.
11781: ** <tr><td>DELETE <td>UPDATE <td>
11782: ** The new change is ignored. This case does not occur if the new
11783: ** changeset was recorded immediately after the changesets already
11784: ** added to the changegroup.
11785: ** <tr><td>DELETE <td>DELETE <td>
11786: ** The new change is ignored. This case does not occur if the new
11787: ** changeset was recorded immediately after the changesets already
11788: ** added to the changegroup.
11789: ** </table>
11790: **
11791: ** If the new changeset contains changes to a table that is already present
11792: ** in the changegroup, then the number of columns and the position of the
11793: ** primary key columns for the table must be consistent. If this is not the
11794: ** case, this function fails with SQLITE_SCHEMA. If the input changeset
11795: ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11796: ** returned. Or, if an out-of-memory condition occurs during processing, this
11797: ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11798: ** of the final contents of the changegroup is undefined.
11799: **
11800: ** If no error occurs, SQLITE_OK is returned.
11801: */
11802: SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11803:
11804: /*
11805: ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11806: ** METHOD: sqlite3_changegroup
11807: **
11808: ** Obtain a buffer containing a changeset (or patchset) representing the
11809: ** current contents of the changegroup. If the inputs to the changegroup
11810: ** were themselves changesets, the output is a changeset. Or, if the
11811: ** inputs were patchsets, the output is also a patchset.
11812: **
11813: ** As with the output of the sqlite3session_changeset() and
11814: ** sqlite3session_patchset() functions, all changes related to a single
11815: ** table are grouped together in the output of this function. Tables appear
11816: ** in the same order as for the very first changeset added to the changegroup.
11817: ** If the second or subsequent changesets added to the changegroup contain
11818: ** changes for tables that do not appear in the first changeset, they are
11819: ** appended onto the end of the output changeset, again in the order in
11820: ** which they are first encountered.
11821: **
11822: ** If an error occurs, an SQLite error code is returned and the output
11823: ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11824: ** is returned and the output variables are set to the size of and a
11825: ** pointer to the output buffer, respectively. In this case it is the
11826: ** responsibility of the caller to eventually free the buffer using a
11827: ** call to sqlite3_free().
11828: */
11829: SQLITE_API int sqlite3changegroup_output(
11830: sqlite3_changegroup*,
11831: int *pnData, /* OUT: Size of output buffer in bytes */
11832: void **ppData /* OUT: Pointer to output buffer */
11833: );
11834:
11835: /*
11836: ** CAPI3REF: Delete A Changegroup Object
11837: ** DESTRUCTOR: sqlite3_changegroup
11838: */
11839: SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11840:
11841: /*
11842: ** CAPI3REF: Apply A Changeset To A Database
11843: **
11844: ** Apply a changeset or patchset to a database. These functions attempt to
11845: ** update the "main" database attached to handle db with the changes found in
11846: ** the changeset passed via the second and third arguments.
11847: **
11848: ** The fourth argument (xFilter) passed to these functions is the "filter
11849: ** callback". If it is not NULL, then for each table affected by at least one
11850: ** change in the changeset, the filter callback is invoked with
11851: ** the table name as the second argument, and a copy of the context pointer
11852: ** passed as the sixth argument as the first. If the "filter callback"
11853: ** returns zero, then no attempt is made to apply any changes to the table.
11854: ** Otherwise, if the return value is non-zero or the xFilter argument to
11855: ** is NULL, all changes related to the table are attempted.
11856: **
11857: ** For each table that is not excluded by the filter callback, this function
11858: ** tests that the target database contains a compatible table. A table is
11859: ** considered compatible if all of the following are true:
11860: **
11861: ** <ul>
11862: ** <li> The table has the same name as the name recorded in the
11863: ** changeset, and
11864: ** <li> The table has at least as many columns as recorded in the
11865: ** changeset, and
11866: ** <li> The table has primary key columns in the same position as
11867: ** recorded in the changeset.
11868: ** </ul>
11869: **
11870: ** If there is no compatible table, it is not an error, but none of the
11871: ** changes associated with the table are applied. A warning message is issued
11872: ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11873: ** one such warning is issued for each table in the changeset.
11874: **
11875: ** For each change for which there is a compatible table, an attempt is made
11876: ** to modify the table contents according to the UPDATE, INSERT or DELETE
11877: ** change. If a change cannot be applied cleanly, the conflict handler
11878: ** function passed as the fifth argument to sqlite3changeset_apply() may be
11879: ** invoked. A description of exactly when the conflict handler is invoked for
11880: ** each type of change is below.
11881: **
11882: ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11883: ** of passing anything other than a valid function pointer as the xConflict
11884: ** argument are undefined.
11885: **
11886: ** Each time the conflict handler function is invoked, it must return one
11887: ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11888: ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11889: ** if the second argument passed to the conflict handler is either
11890: ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11891: ** returns an illegal value, any changes already made are rolled back and
11892: ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11893: ** actions are taken by sqlite3changeset_apply() depending on the value
11894: ** returned by each invocation of the conflict-handler function. Refer to
11895: ** the documentation for the three
11896: ** [SQLITE_CHANGESET_OMIT|available return values] for details.
11897: **
11898: ** <dl>
11899: ** <dt>DELETE Changes<dd>
11900: ** For each DELETE change, the function checks if the target database
11901: ** contains a row with the same primary key value (or values) as the
11902: ** original row values stored in the changeset. If it does, and the values
11903: ** stored in all non-primary key columns also match the values stored in
11904: ** the changeset the row is deleted from the target database.
11905: **
11906: ** If a row with matching primary key values is found, but one or more of
11907: ** the non-primary key fields contains a value different from the original
11908: ** row value stored in the changeset, the conflict-handler function is
11909: ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11910: ** database table has more columns than are recorded in the changeset,
11911: ** only the values of those non-primary key fields are compared against
11912: ** the current database contents - any trailing database table columns
11913: ** are ignored.
11914: **
11915: ** If no row with matching primary key values is found in the database,
11916: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11917: ** passed as the second argument.
11918: **
11919: ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11920: ** (which can only happen if a foreign key constraint is violated), the
11921: ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11922: ** passed as the second argument. This includes the case where the DELETE
11923: ** operation is attempted because an earlier call to the conflict handler
11924: ** function returned [SQLITE_CHANGESET_REPLACE].
11925: **
11926: ** <dt>INSERT Changes<dd>
11927: ** For each INSERT change, an attempt is made to insert the new row into
11928: ** the database. If the changeset row contains fewer fields than the
11929: ** database table, the trailing fields are populated with their default
11930: ** values.
11931: **
11932: ** If the attempt to insert the row fails because the database already
11933: ** contains a row with the same primary key values, the conflict handler
11934: ** function is invoked with the second argument set to
11935: ** [SQLITE_CHANGESET_CONFLICT].
11936: **
11937: ** If the attempt to insert the row fails because of some other constraint
11938: ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11939: ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11940: ** This includes the case where the INSERT operation is re-attempted because
11941: ** an earlier call to the conflict handler function returned
11942: ** [SQLITE_CHANGESET_REPLACE].
11943: **
11944: ** <dt>UPDATE Changes<dd>
11945: ** For each UPDATE change, the function checks if the target database
11946: ** contains a row with the same primary key value (or values) as the
11947: ** original row values stored in the changeset. If it does, and the values
11948: ** stored in all modified non-primary key columns also match the values
11949: ** stored in the changeset the row is updated within the target database.
11950: **
11951: ** If a row with matching primary key values is found, but one or more of
11952: ** the modified non-primary key fields contains a value different from an
11953: ** original row value stored in the changeset, the conflict-handler function
11954: ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11955: ** UPDATE changes only contain values for non-primary key fields that are
11956: ** to be modified, only those fields need to match the original values to
11957: ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11958: **
11959: ** If no row with matching primary key values is found in the database,
11960: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11961: ** passed as the second argument.
11962: **
11963: ** If the UPDATE operation is attempted, but SQLite returns
11964: ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11965: ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11966: ** This includes the case where the UPDATE operation is attempted after
11967: ** an earlier call to the conflict handler function returned
11968: ** [SQLITE_CHANGESET_REPLACE].
11969: ** </dl>
11970: **
11971: ** It is safe to execute SQL statements, including those that write to the
11972: ** table that the callback related to, from within the xConflict callback.
11973: ** This can be used to further customize the application's conflict
11974: ** resolution strategy.
11975: **
11976: ** All changes made by these functions are enclosed in a savepoint transaction.
11977: ** If any other error (aside from a constraint failure when attempting to
11978: ** write to the target database) occurs, then the savepoint transaction is
11979: ** rolled back, restoring the target database to its original state, and an
11980: ** SQLite error code returned.
11981: **
11982: ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11983: ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11984: ** may set (*ppRebase) to point to a "rebase" that may be used with the
11985: ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11986: ** is set to the size of the buffer in bytes. It is the responsibility of the
11987: ** caller to eventually free any such buffer using sqlite3_free(). The buffer
11988: ** is only allocated and populated if one or more conflicts were encountered
11989: ** while applying the patchset. See comments surrounding the sqlite3_rebaser
11990: ** APIs for further details.
11991: **
11992: ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11993: ** may be modified by passing a combination of
11994: ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11995: **
11996: ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11997: ** and therefore subject to change.
11998: */
11999: SQLITE_API int sqlite3changeset_apply(
12000: sqlite3 *db, /* Apply change to "main" db of this handle */
12001: int nChangeset, /* Size of changeset in bytes */
12002: void *pChangeset, /* Changeset blob */
12003: int(*xFilter)(
12004: void *pCtx, /* Copy of sixth arg to _apply() */
12005: const char *zTab /* Table name */
12006: ),
12007: int(*xConflict)(
12008: void *pCtx, /* Copy of sixth arg to _apply() */
12009: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12010: sqlite3_changeset_iter *p /* Handle describing change and conflict */
12011: ),
12012: void *pCtx /* First argument passed to xConflict */
12013: );
12014: SQLITE_API int sqlite3changeset_apply_v2(
12015: sqlite3 *db, /* Apply change to "main" db of this handle */
12016: int nChangeset, /* Size of changeset in bytes */
12017: void *pChangeset, /* Changeset blob */
12018: int(*xFilter)(
12019: void *pCtx, /* Copy of sixth arg to _apply() */
12020: const char *zTab /* Table name */
12021: ),
12022: int(*xConflict)(
12023: void *pCtx, /* Copy of sixth arg to _apply() */
12024: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12025: sqlite3_changeset_iter *p /* Handle describing change and conflict */
12026: ),
12027: void *pCtx, /* First argument passed to xConflict */
12028: void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12029: int flags /* SESSION_CHANGESETAPPLY_* flags */
12030: );
12031:
12032: /*
12033: ** CAPI3REF: Flags for sqlite3changeset_apply_v2
12034: **
12035: ** The following flags may passed via the 9th parameter to
12036: ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12037: **
12038: ** <dl>
12039: ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12040: ** Usually, the sessions module encloses all operations performed by
12041: ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12042: ** SAVEPOINT is committed if the changeset or patchset is successfully
12043: ** applied, or rolled back if an error occurs. Specifying this flag
12044: ** causes the sessions module to omit this savepoint. In this case, if the
12045: ** caller has an open transaction or savepoint when apply_v2() is called,
12046: ** it may revert the partially applied changeset by rolling it back.
12047: **
12048: ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12049: ** Invert the changeset before applying it. This is equivalent to inverting
12050: ** a changeset using sqlite3changeset_invert() before applying it. It is
12051: ** an error to specify this flag with a patchset.
12052: **
12053: ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12054: ** Do not invoke the conflict handler callback for any changes that
12055: ** would not actually modify the database even if they were applied.
12056: ** Specifically, this means that the conflict handler is not invoked
12057: ** for:
12058: ** <ul>
12059: ** <li>a delete change if the row being deleted cannot be found,
12060: ** <li>an update change if the modified fields are already set to
12061: ** their new values in the conflicting row, or
12062: ** <li>an insert change if all fields of the conflicting row match
12063: ** the row being inserted.
12064: ** </ul>
12065: */
12066: #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12067: #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12068: #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12069:
12070: /*
12071: ** CAPI3REF: Constants Passed To The Conflict Handler
12072: **
12073: ** Values that may be passed as the second argument to a conflict-handler.
12074: **
12075: ** <dl>
12076: ** <dt>SQLITE_CHANGESET_DATA<dd>
12077: ** The conflict handler is invoked with CHANGESET_DATA as the second argument
12078: ** when processing a DELETE or UPDATE change if a row with the required
12079: ** PRIMARY KEY fields is present in the database, but one or more other
12080: ** (non primary-key) fields modified by the update do not contain the
12081: ** expected "before" values.
12082: **
12083: ** The conflicting row, in this case, is the database row with the matching
12084: ** primary key.
12085: **
12086: ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12087: ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12088: ** argument when processing a DELETE or UPDATE change if a row with the
12089: ** required PRIMARY KEY fields is not present in the database.
12090: **
12091: ** There is no conflicting row in this case. The results of invoking the
12092: ** sqlite3changeset_conflict() API are undefined.
12093: **
12094: ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12095: ** CHANGESET_CONFLICT is passed as the second argument to the conflict
12096: ** handler while processing an INSERT change if the operation would result
12097: ** in duplicate primary key values.
12098: **
12099: ** The conflicting row in this case is the database row with the matching
12100: ** primary key.
12101: **
12102: ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12103: ** If foreign key handling is enabled, and applying a changeset leaves the
12104: ** database in a state containing foreign key violations, the conflict
12105: ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12106: ** exactly once before the changeset is committed. If the conflict handler
12107: ** returns CHANGESET_OMIT, the changes, including those that caused the
12108: ** foreign key constraint violation, are committed. Or, if it returns
12109: ** CHANGESET_ABORT, the changeset is rolled back.
12110: **
12111: ** No current or conflicting row information is provided. The only function
12112: ** it is possible to call on the supplied sqlite3_changeset_iter handle
12113: ** is sqlite3changeset_fk_conflicts().
12114: **
12115: ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12116: ** If any other constraint violation occurs while applying a change (i.e.
12117: ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12118: ** invoked with CHANGESET_CONSTRAINT as the second argument.
12119: **
12120: ** There is no conflicting row in this case. The results of invoking the
12121: ** sqlite3changeset_conflict() API are undefined.
12122: **
12123: ** </dl>
12124: */
12125: #define SQLITE_CHANGESET_DATA 1
12126: #define SQLITE_CHANGESET_NOTFOUND 2
12127: #define SQLITE_CHANGESET_CONFLICT 3
12128: #define SQLITE_CHANGESET_CONSTRAINT 4
12129: #define SQLITE_CHANGESET_FOREIGN_KEY 5
12130:
12131: /*
12132: ** CAPI3REF: Constants Returned By The Conflict Handler
12133: **
12134: ** A conflict handler callback must return one of the following three values.
12135: **
12136: ** <dl>
12137: ** <dt>SQLITE_CHANGESET_OMIT<dd>
12138: ** If a conflict handler returns this value no special action is taken. The
12139: ** change that caused the conflict is not applied. The session module
12140: ** continues to the next change in the changeset.
12141: **
12142: ** <dt>SQLITE_CHANGESET_REPLACE<dd>
12143: ** This value may only be returned if the second argument to the conflict
12144: ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12145: ** is not the case, any changes applied so far are rolled back and the
12146: ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12147: **
12148: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12149: ** handler, then the conflicting row is either updated or deleted, depending
12150: ** on the type of change.
12151: **
12152: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12153: ** handler, then the conflicting row is removed from the database and a
12154: ** second attempt to apply the change is made. If this second attempt fails,
12155: ** the original row is restored to the database before continuing.
12156: **
12157: ** <dt>SQLITE_CHANGESET_ABORT<dd>
12158: ** If this value is returned, any changes applied so far are rolled back
12159: ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12160: ** </dl>
12161: */
12162: #define SQLITE_CHANGESET_OMIT 0
12163: #define SQLITE_CHANGESET_REPLACE 1
12164: #define SQLITE_CHANGESET_ABORT 2
12165:
12166: /*
12167: ** CAPI3REF: Rebasing changesets
12168: ** EXPERIMENTAL
12169: **
12170: ** Suppose there is a site hosting a database in state S0. And that
12171: ** modifications are made that move that database to state S1 and a
12172: ** changeset recorded (the "local" changeset). Then, a changeset based
12173: ** on S0 is received from another site (the "remote" changeset) and
12174: ** applied to the database. The database is then in state
12175: ** (S1+"remote"), where the exact state depends on any conflict
12176: ** resolution decisions (OMIT or REPLACE) made while applying "remote".
12177: ** Rebasing a changeset is to update it to take those conflict
12178: ** resolution decisions into account, so that the same conflicts
12179: ** do not have to be resolved elsewhere in the network.
12180: **
12181: ** For example, if both the local and remote changesets contain an
12182: ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12183: **
12184: ** local: INSERT INTO t1 VALUES(1, 'v1');
12185: ** remote: INSERT INTO t1 VALUES(1, 'v2');
12186: **
12187: ** and the conflict resolution is REPLACE, then the INSERT change is
12188: ** removed from the local changeset (it was overridden). Or, if the
12189: ** conflict resolution was "OMIT", then the local changeset is modified
12190: ** to instead contain:
12191: **
12192: ** UPDATE t1 SET b = 'v2' WHERE a=1;
12193: **
12194: ** Changes within the local changeset are rebased as follows:
12195: **
12196: ** <dl>
12197: ** <dt>Local INSERT<dd>
12198: ** This may only conflict with a remote INSERT. If the conflict
12199: ** resolution was OMIT, then add an UPDATE change to the rebased
12200: ** changeset. Or, if the conflict resolution was REPLACE, add
12201: ** nothing to the rebased changeset.
12202: **
12203: ** <dt>Local DELETE<dd>
12204: ** This may conflict with a remote UPDATE or DELETE. In both cases the
12205: ** only possible resolution is OMIT. If the remote operation was a
12206: ** DELETE, then add no change to the rebased changeset. If the remote
12207: ** operation was an UPDATE, then the old.* fields of change are updated
12208: ** to reflect the new.* values in the UPDATE.
12209: **
12210: ** <dt>Local UPDATE<dd>
12211: ** This may conflict with a remote UPDATE or DELETE. If it conflicts
12212: ** with a DELETE, and the conflict resolution was OMIT, then the update
12213: ** is changed into an INSERT. Any undefined values in the new.* record
12214: ** from the update change are filled in using the old.* values from
12215: ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12216: ** the UPDATE change is simply omitted from the rebased changeset.
12217: **
12218: ** If conflict is with a remote UPDATE and the resolution is OMIT, then
12219: ** the old.* values are rebased using the new.* values in the remote
12220: ** change. Or, if the resolution is REPLACE, then the change is copied
12221: ** into the rebased changeset with updates to columns also updated by
12222: ** the conflicting remote UPDATE removed. If this means no columns would
12223: ** be updated, the change is omitted.
12224: ** </dl>
12225: **
12226: ** A local change may be rebased against multiple remote changes
12227: ** simultaneously. If a single key is modified by multiple remote
12228: ** changesets, they are combined as follows before the local changeset
12229: ** is rebased:
12230: **
12231: ** <ul>
12232: ** <li> If there has been one or more REPLACE resolutions on a
12233: ** key, it is rebased according to a REPLACE.
12234: **
12235: ** <li> If there have been no REPLACE resolutions on a key, then
12236: ** the local changeset is rebased according to the most recent
12237: ** of the OMIT resolutions.
12238: ** </ul>
12239: **
12240: ** Note that conflict resolutions from multiple remote changesets are
12241: ** combined on a per-field basis, not per-row. This means that in the
12242: ** case of multiple remote UPDATE operations, some fields of a single
12243: ** local change may be rebased for REPLACE while others are rebased for
12244: ** OMIT.
12245: **
12246: ** In order to rebase a local changeset, the remote changeset must first
12247: ** be applied to the local database using sqlite3changeset_apply_v2() and
12248: ** the buffer of rebase information captured. Then:
12249: **
12250: ** <ol>
12251: ** <li> An sqlite3_rebaser object is created by calling
12252: ** sqlite3rebaser_create().
12253: ** <li> The new object is configured with the rebase buffer obtained from
12254: ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12255: ** If the local changeset is to be rebased against multiple remote
12256: ** changesets, then sqlite3rebaser_configure() should be called
12257: ** multiple times, in the same order that the multiple
12258: ** sqlite3changeset_apply_v2() calls were made.
12259: ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12260: ** <li> The sqlite3_rebaser object is deleted by calling
12261: ** sqlite3rebaser_delete().
12262: ** </ol>
12263: */
12264: typedef struct sqlite3_rebaser sqlite3_rebaser;
12265:
12266: /*
12267: ** CAPI3REF: Create a changeset rebaser object.
12268: ** EXPERIMENTAL
12269: **
12270: ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12271: ** point to the new object and return SQLITE_OK. Otherwise, if an error
12272: ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12273: ** to NULL.
12274: */
12275: SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12276:
12277: /*
12278: ** CAPI3REF: Configure a changeset rebaser object.
12279: ** EXPERIMENTAL
12280: **
12281: ** Configure the changeset rebaser object to rebase changesets according
12282: ** to the conflict resolutions described by buffer pRebase (size nRebase
12283: ** bytes), which must have been obtained from a previous call to
12284: ** sqlite3changeset_apply_v2().
12285: */
12286: SQLITE_API int sqlite3rebaser_configure(
12287: sqlite3_rebaser*,
12288: int nRebase, const void *pRebase
12289: );
12290:
12291: /*
12292: ** CAPI3REF: Rebase a changeset
12293: ** EXPERIMENTAL
12294: **
12295: ** Argument pIn must point to a buffer containing a changeset nIn bytes
12296: ** in size. This function allocates and populates a buffer with a copy
12297: ** of the changeset rebased according to the configuration of the
12298: ** rebaser object passed as the first argument. If successful, (*ppOut)
12299: ** is set to point to the new buffer containing the rebased changeset and
12300: ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12301: ** responsibility of the caller to eventually free the new buffer using
12302: ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12303: ** are set to zero and an SQLite error code returned.
12304: */
12305: SQLITE_API int sqlite3rebaser_rebase(
12306: sqlite3_rebaser*,
12307: int nIn, const void *pIn,
12308: int *pnOut, void **ppOut
12309: );
12310:
12311: /*
12312: ** CAPI3REF: Delete a changeset rebaser object.
12313: ** EXPERIMENTAL
12314: **
12315: ** Delete the changeset rebaser object and all associated resources. There
12316: ** should be one call to this function for each successful invocation
12317: ** of sqlite3rebaser_create().
12318: */
12319: SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12320:
12321: /*
12322: ** CAPI3REF: Streaming Versions of API functions.
12323: **
12324: ** The six streaming API xxx_strm() functions serve similar purposes to the
12325: ** corresponding non-streaming API functions:
12326: **
12327: ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12328: ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12329: ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12330: ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12331: ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12332: ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12333: ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12334: ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12335: ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12336: ** </table>
12337: **
12338: ** Non-streaming functions that accept changesets (or patchsets) as input
12339: ** require that the entire changeset be stored in a single buffer in memory.
12340: ** Similarly, those that return a changeset or patchset do so by returning
12341: ** a pointer to a single large buffer allocated using sqlite3_malloc().
12342: ** Normally this is convenient. However, if an application running in a
12343: ** low-memory environment is required to handle very large changesets, the
12344: ** large contiguous memory allocations required can become onerous.
12345: **
12346: ** In order to avoid this problem, instead of a single large buffer, input
12347: ** is passed to a streaming API functions by way of a callback function that
12348: ** the sessions module invokes to incrementally request input data as it is
12349: ** required. In all cases, a pair of API function parameters such as
12350: **
12351: ** <pre>
12352: ** int nChangeset,
12353: ** void *pChangeset,
12354: ** </pre>
12355: **
12356: ** Is replaced by:
12357: **
12358: ** <pre>
12359: ** int (*xInput)(void *pIn, void *pData, int *pnData),
12360: ** void *pIn,
12361: ** </pre>
12362: **
12363: ** Each time the xInput callback is invoked by the sessions module, the first
12364: ** argument passed is a copy of the supplied pIn context pointer. The second
12365: ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12366: ** error occurs the xInput method should copy up to (*pnData) bytes of data
12367: ** into the buffer and set (*pnData) to the actual number of bytes copied
12368: ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12369: ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12370: ** error code should be returned. In all cases, if an xInput callback returns
12371: ** an error, all processing is abandoned and the streaming API function
12372: ** returns a copy of the error code to the caller.
12373: **
12374: ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12375: ** invoked by the sessions module at any point during the lifetime of the
12376: ** iterator. If such an xInput callback returns an error, the iterator enters
12377: ** an error state, whereby all subsequent calls to iterator functions
12378: ** immediately fail with the same error code as returned by xInput.
12379: **
12380: ** Similarly, streaming API functions that return changesets (or patchsets)
12381: ** return them in chunks by way of a callback function instead of via a
12382: ** pointer to a single large buffer. In this case, a pair of parameters such
12383: ** as:
12384: **
12385: ** <pre>
12386: ** int *pnChangeset,
12387: ** void **ppChangeset,
12388: ** </pre>
12389: **
12390: ** Is replaced by:
12391: **
12392: ** <pre>
12393: ** int (*xOutput)(void *pOut, const void *pData, int nData),
12394: ** void *pOut
12395: ** </pre>
12396: **
12397: ** The xOutput callback is invoked zero or more times to return data to
12398: ** the application. The first parameter passed to each call is a copy of the
12399: ** pOut pointer supplied by the application. The second parameter, pData,
12400: ** points to a buffer nData bytes in size containing the chunk of output
12401: ** data being returned. If the xOutput callback successfully processes the
12402: ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12403: ** it should return some other SQLite error code. In this case processing
12404: ** is immediately abandoned and the streaming API function returns a copy
12405: ** of the xOutput error code to the application.
12406: **
12407: ** The sessions module never invokes an xOutput callback with the third
12408: ** parameter set to a value less than or equal to zero. Other than this,
12409: ** no guarantees are made as to the size of the chunks of data returned.
12410: */
12411: SQLITE_API int sqlite3changeset_apply_strm(
12412: sqlite3 *db, /* Apply change to "main" db of this handle */
12413: int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12414: void *pIn, /* First arg for xInput */
12415: int(*xFilter)(
12416: void *pCtx, /* Copy of sixth arg to _apply() */
12417: const char *zTab /* Table name */
12418: ),
12419: int(*xConflict)(
12420: void *pCtx, /* Copy of sixth arg to _apply() */
12421: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12422: sqlite3_changeset_iter *p /* Handle describing change and conflict */
12423: ),
12424: void *pCtx /* First argument passed to xConflict */
12425: );
12426: SQLITE_API int sqlite3changeset_apply_v2_strm(
12427: sqlite3 *db, /* Apply change to "main" db of this handle */
12428: int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12429: void *pIn, /* First arg for xInput */
12430: int(*xFilter)(
12431: void *pCtx, /* Copy of sixth arg to _apply() */
12432: const char *zTab /* Table name */
12433: ),
12434: int(*xConflict)(
12435: void *pCtx, /* Copy of sixth arg to _apply() */
12436: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12437: sqlite3_changeset_iter *p /* Handle describing change and conflict */
12438: ),
12439: void *pCtx, /* First argument passed to xConflict */
12440: void **ppRebase, int *pnRebase,
12441: int flags
12442: );
12443: SQLITE_API int sqlite3changeset_concat_strm(
12444: int (*xInputA)(void *pIn, void *pData, int *pnData),
12445: void *pInA,
12446: int (*xInputB)(void *pIn, void *pData, int *pnData),
12447: void *pInB,
12448: int (*xOutput)(void *pOut, const void *pData, int nData),
12449: void *pOut
12450: );
12451: SQLITE_API int sqlite3changeset_invert_strm(
12452: int (*xInput)(void *pIn, void *pData, int *pnData),
12453: void *pIn,
12454: int (*xOutput)(void *pOut, const void *pData, int nData),
12455: void *pOut
12456: );
12457: SQLITE_API int sqlite3changeset_start_strm(
12458: sqlite3_changeset_iter **pp,
12459: int (*xInput)(void *pIn, void *pData, int *pnData),
12460: void *pIn
12461: );
12462: SQLITE_API int sqlite3changeset_start_v2_strm(
12463: sqlite3_changeset_iter **pp,
12464: int (*xInput)(void *pIn, void *pData, int *pnData),
12465: void *pIn,
12466: int flags
12467: );
12468: SQLITE_API int sqlite3session_changeset_strm(
12469: sqlite3_session *pSession,
12470: int (*xOutput)(void *pOut, const void *pData, int nData),
12471: void *pOut
12472: );
12473: SQLITE_API int sqlite3session_patchset_strm(
12474: sqlite3_session *pSession,
12475: int (*xOutput)(void *pOut, const void *pData, int nData),
12476: void *pOut
12477: );
12478: SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12479: int (*xInput)(void *pIn, void *pData, int *pnData),
12480: void *pIn
12481: );
12482: SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12483: int (*xOutput)(void *pOut, const void *pData, int nData),
12484: void *pOut
12485: );
12486: SQLITE_API int sqlite3rebaser_rebase_strm(
12487: sqlite3_rebaser *pRebaser,
12488: int (*xInput)(void *pIn, void *pData, int *pnData),
12489: void *pIn,
12490: int (*xOutput)(void *pOut, const void *pData, int nData),
12491: void *pOut
12492: );
12493:
12494: /*
12495: ** CAPI3REF: Configure global parameters
12496: **
12497: ** The sqlite3session_config() interface is used to make global configuration
12498: ** changes to the sessions module in order to tune it to the specific needs
12499: ** of the application.
12500: **
12501: ** The sqlite3session_config() interface is not threadsafe. If it is invoked
12502: ** while any other thread is inside any other sessions method then the
12503: ** results are undefined. Furthermore, if it is invoked after any sessions
12504: ** related objects have been created, the results are also undefined.
12505: **
12506: ** The first argument to the sqlite3session_config() function must be one
12507: ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12508: ** interpretation of the (void*) value passed as the second parameter and
12509: ** the effect of calling this function depends on the value of the first
12510: ** parameter.
12511: **
12512: ** <dl>
12513: ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12514: ** By default, the sessions module streaming interfaces attempt to input
12515: ** and output data in approximately 1 KiB chunks. This operand may be used
12516: ** to set and query the value of this configuration setting. The pointer
12517: ** passed as the second argument must point to a value of type (int).
12518: ** If this value is greater than 0, it is used as the new streaming data
12519: ** chunk size for both input and output. Before returning, the (int) value
12520: ** pointed to by pArg is set to the final value of the streaming interface
12521: ** chunk size.
12522: ** </dl>
12523: **
12524: ** This function returns SQLITE_OK if successful, or an SQLite error code
12525: ** otherwise.
12526: */
12527: SQLITE_API int sqlite3session_config(int op, void *pArg);
12528:
12529: /*
12530: ** CAPI3REF: Values for sqlite3session_config().
12531: */
12532: #define SQLITE_SESSION_CONFIG_STRMSIZE 1
12533:
12534: /*
12535: ** Make sure we can call this stuff from C++.
12536: */
12537: #ifdef __cplusplus
12538: }
12539: #endif
12540:
12541: #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12542:
12543: /******** End of sqlite3session.h *********/
12544: /******** Begin file fts5.h *********/
12545: /*
12546: ** 2014 May 31
12547: **
12548: ** The author disclaims copyright to this source code. In place of
12549: ** a legal notice, here is a blessing:
12550: **
12551: ** May you do good and not evil.
12552: ** May you find forgiveness for yourself and forgive others.
12553: ** May you share freely, never taking more than you give.
12554: **
12555: ******************************************************************************
12556: **
12557: ** Interfaces to extend FTS5. Using the interfaces defined in this file,
12558: ** FTS5 may be extended with:
12559: **
12560: ** * custom tokenizers, and
12561: ** * custom auxiliary functions.
12562: */
12563:
12564:
12565: #ifndef _FTS5_H
12566: #define _FTS5_H
12567:
12568:
12569: #ifdef __cplusplus
12570: extern "C" {
12571: #endif
12572:
12573: /*************************************************************************
12574: ** CUSTOM AUXILIARY FUNCTIONS
12575: **
12576: ** Virtual table implementations may overload SQL functions by implementing
12577: ** the sqlite3_module.xFindFunction() method.
12578: */
12579:
12580: typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12581: typedef struct Fts5Context Fts5Context;
12582: typedef struct Fts5PhraseIter Fts5PhraseIter;
12583:
12584: typedef void (*fts5_extension_function)(
12585: const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12586: Fts5Context *pFts, /* First arg to pass to pApi functions */
12587: sqlite3_context *pCtx, /* Context for returning result/error */
12588: int nVal, /* Number of values in apVal[] array */
12589: sqlite3_value **apVal /* Array of trailing arguments */
12590: );
12591:
12592: struct Fts5PhraseIter {
12593: const unsigned char *a;
12594: const unsigned char *b;
12595: };
12596:
12597: /*
12598: ** EXTENSION API FUNCTIONS
12599: **
12600: ** xUserData(pFts):
12601: ** Return a copy of the context pointer the extension function was
12602: ** registered with.
12603: **
12604: ** xColumnTotalSize(pFts, iCol, pnToken):
12605: ** If parameter iCol is less than zero, set output variable *pnToken
12606: ** to the total number of tokens in the FTS5 table. Or, if iCol is
12607: ** non-negative but less than the number of columns in the table, return
12608: ** the total number of tokens in column iCol, considering all rows in
12609: ** the FTS5 table.
12610: **
12611: ** If parameter iCol is greater than or equal to the number of columns
12612: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12613: ** an OOM condition or IO error), an appropriate SQLite error code is
12614: ** returned.
12615: **
12616: ** xColumnCount(pFts):
12617: ** Return the number of columns in the table.
12618: **
12619: ** xColumnSize(pFts, iCol, pnToken):
12620: ** If parameter iCol is less than zero, set output variable *pnToken
12621: ** to the total number of tokens in the current row. Or, if iCol is
12622: ** non-negative but less than the number of columns in the table, set
12623: ** *pnToken to the number of tokens in column iCol of the current row.
12624: **
12625: ** If parameter iCol is greater than or equal to the number of columns
12626: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12627: ** an OOM condition or IO error), an appropriate SQLite error code is
12628: ** returned.
12629: **
12630: ** This function may be quite inefficient if used with an FTS5 table
12631: ** created with the "columnsize=0" option.
12632: **
12633: ** xColumnText:
12634: ** This function attempts to retrieve the text of column iCol of the
12635: ** current document. If successful, (*pz) is set to point to a buffer
12636: ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12637: ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12638: ** if an error occurs, an SQLite error code is returned and the final values
12639: ** of (*pz) and (*pn) are undefined.
12640: **
12641: ** xPhraseCount:
12642: ** Returns the number of phrases in the current query expression.
12643: **
12644: ** xPhraseSize:
12645: ** Returns the number of tokens in phrase iPhrase of the query. Phrases
12646: ** are numbered starting from zero.
12647: **
12648: ** xInstCount:
12649: ** Set *pnInst to the total number of occurrences of all phrases within
12650: ** the query within the current row. Return SQLITE_OK if successful, or
12651: ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12652: **
12653: ** This API can be quite slow if used with an FTS5 table created with the
12654: ** "detail=none" or "detail=column" option. If the FTS5 table is created
12655: ** with either "detail=none" or "detail=column" and "content=" option
12656: ** (i.e. if it is a contentless table), then this API always returns 0.
12657: **
12658: ** xInst:
12659: ** Query for the details of phrase match iIdx within the current row.
12660: ** Phrase matches are numbered starting from zero, so the iIdx argument
12661: ** should be greater than or equal to zero and smaller than the value
12662: ** output by xInstCount().
12663: **
12664: ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12665: ** to the column in which it occurs and *piOff the token offset of the
12666: ** first token of the phrase. Returns SQLITE_OK if successful, or an error
12667: ** code (i.e. SQLITE_NOMEM) if an error occurs.
12668: **
12669: ** This API can be quite slow if used with an FTS5 table created with the
12670: ** "detail=none" or "detail=column" option.
12671: **
12672: ** xRowid:
12673: ** Returns the rowid of the current row.
12674: **
12675: ** xTokenize:
12676: ** Tokenize text using the tokenizer belonging to the FTS5 table.
12677: **
12678: ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12679: ** This API function is used to query the FTS table for phrase iPhrase
12680: ** of the current query. Specifically, a query equivalent to:
12681: **
12682: ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12683: **
12684: ** with $p set to a phrase equivalent to the phrase iPhrase of the
12685: ** current query is executed. Any column filter that applies to
12686: ** phrase iPhrase of the current query is included in $p. For each
12687: ** row visited, the callback function passed as the fourth argument
12688: ** is invoked. The context and API objects passed to the callback
12689: ** function may be used to access the properties of each matched row.
12690: ** Invoking Api.xUserData() returns a copy of the pointer passed as
12691: ** the third argument to pUserData.
12692: **
12693: ** If the callback function returns any value other than SQLITE_OK, the
12694: ** query is abandoned and the xQueryPhrase function returns immediately.
12695: ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12696: ** Otherwise, the error code is propagated upwards.
12697: **
12698: ** If the query runs to completion without incident, SQLITE_OK is returned.
12699: ** Or, if some error occurs before the query completes or is aborted by
12700: ** the callback, an SQLite error code is returned.
12701: **
12702: **
12703: ** xSetAuxdata(pFts5, pAux, xDelete)
12704: **
12705: ** Save the pointer passed as the second argument as the extension function's
12706: ** "auxiliary data". The pointer may then be retrieved by the current or any
12707: ** future invocation of the same fts5 extension function made as part of
12708: ** the same MATCH query using the xGetAuxdata() API.
12709: **
12710: ** Each extension function is allocated a single auxiliary data slot for
12711: ** each FTS query (MATCH expression). If the extension function is invoked
12712: ** more than once for a single FTS query, then all invocations share a
12713: ** single auxiliary data context.
12714: **
12715: ** If there is already an auxiliary data pointer when this function is
12716: ** invoked, then it is replaced by the new pointer. If an xDelete callback
12717: ** was specified along with the original pointer, it is invoked at this
12718: ** point.
12719: **
12720: ** The xDelete callback, if one is specified, is also invoked on the
12721: ** auxiliary data pointer after the FTS5 query has finished.
12722: **
12723: ** If an error (e.g. an OOM condition) occurs within this function,
12724: ** the auxiliary data is set to NULL and an error code returned. If the
12725: ** xDelete parameter was not NULL, it is invoked on the auxiliary data
12726: ** pointer before returning.
12727: **
12728: **
12729: ** xGetAuxdata(pFts5, bClear)
12730: **
12731: ** Returns the current auxiliary data pointer for the fts5 extension
12732: ** function. See the xSetAuxdata() method for details.
12733: **
12734: ** If the bClear argument is non-zero, then the auxiliary data is cleared
12735: ** (set to NULL) before this function returns. In this case the xDelete,
12736: ** if any, is not invoked.
12737: **
12738: **
12739: ** xRowCount(pFts5, pnRow)
12740: **
12741: ** This function is used to retrieve the total number of rows in the table.
12742: ** In other words, the same value that would be returned by:
12743: **
12744: ** SELECT count(*) FROM ftstable;
12745: **
12746: ** xPhraseFirst()
12747: ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12748: ** method, to iterate through all instances of a single query phrase within
12749: ** the current row. This is the same information as is accessible via the
12750: ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12751: ** to use, this API may be faster under some circumstances. To iterate
12752: ** through instances of phrase iPhrase, use the following code:
12753: **
12754: ** Fts5PhraseIter iter;
12755: ** int iCol, iOff;
12756: ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12757: ** iCol>=0;
12758: ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12759: ** ){
12760: ** // An instance of phrase iPhrase at offset iOff of column iCol
12761: ** }
12762: **
12763: ** The Fts5PhraseIter structure is defined above. Applications should not
12764: ** modify this structure directly - it should only be used as shown above
12765: ** with the xPhraseFirst() and xPhraseNext() API methods (and by
12766: ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12767: **
12768: ** This API can be quite slow if used with an FTS5 table created with the
12769: ** "detail=none" or "detail=column" option. If the FTS5 table is created
12770: ** with either "detail=none" or "detail=column" and "content=" option
12771: ** (i.e. if it is a contentless table), then this API always iterates
12772: ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12773: **
12774: ** xPhraseNext()
12775: ** See xPhraseFirst above.
12776: **
12777: ** xPhraseFirstColumn()
12778: ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12779: ** and xPhraseNext() APIs described above. The difference is that instead
12780: ** of iterating through all instances of a phrase in the current row, these
12781: ** APIs are used to iterate through the set of columns in the current row
12782: ** that contain one or more instances of a specified phrase. For example:
12783: **
12784: ** Fts5PhraseIter iter;
12785: ** int iCol;
12786: ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12787: ** iCol>=0;
12788: ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12789: ** ){
12790: ** // Column iCol contains at least one instance of phrase iPhrase
12791: ** }
12792: **
12793: ** This API can be quite slow if used with an FTS5 table created with the
12794: ** "detail=none" option. If the FTS5 table is created with either
12795: ** "detail=none" "content=" option (i.e. if it is a contentless table),
12796: ** then this API always iterates through an empty set (all calls to
12797: ** xPhraseFirstColumn() set iCol to -1).
12798: **
12799: ** The information accessed using this API and its companion
12800: ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12801: ** (or xInst/xInstCount). The chief advantage of this API is that it is
12802: ** significantly more efficient than those alternatives when used with
12803: ** "detail=column" tables.
12804: **
12805: ** xPhraseNextColumn()
12806: ** See xPhraseFirstColumn above.
12807: */
12808: struct Fts5ExtensionApi {
12809: int iVersion; /* Currently always set to 2 */
12810:
12811: void *(*xUserData)(Fts5Context*);
12812:
12813: int (*xColumnCount)(Fts5Context*);
12814: int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12815: int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12816:
12817: int (*xTokenize)(Fts5Context*,
12818: const char *pText, int nText, /* Text to tokenize */
12819: void *pCtx, /* Context passed to xToken() */
12820: int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12821: );
12822:
12823: int (*xPhraseCount)(Fts5Context*);
12824: int (*xPhraseSize)(Fts5Context*, int iPhrase);
12825:
12826: int (*xInstCount)(Fts5Context*, int *pnInst);
12827: int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12828:
12829: sqlite3_int64 (*xRowid)(Fts5Context*);
12830: int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12831: int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12832:
12833: int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12834: int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12835: );
12836: int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12837: void *(*xGetAuxdata)(Fts5Context*, int bClear);
12838:
12839: int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12840: void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12841:
12842: int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12843: void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12844: };
12845:
12846: /*
12847: ** CUSTOM AUXILIARY FUNCTIONS
12848: *************************************************************************/
12849:
12850: /*************************************************************************
12851: ** CUSTOM TOKENIZERS
12852: **
12853: ** Applications may also register custom tokenizer types. A tokenizer
12854: ** is registered by providing fts5 with a populated instance of the
12855: ** following structure. All structure methods must be defined, setting
12856: ** any member of the fts5_tokenizer struct to NULL leads to undefined
12857: ** behaviour. The structure methods are expected to function as follows:
12858: **
12859: ** xCreate:
12860: ** This function is used to allocate and initialize a tokenizer instance.
12861: ** A tokenizer instance is required to actually tokenize text.
12862: **
12863: ** The first argument passed to this function is a copy of the (void*)
12864: ** pointer provided by the application when the fts5_tokenizer object
12865: ** was registered with FTS5 (the third argument to xCreateTokenizer()).
12866: ** The second and third arguments are an array of nul-terminated strings
12867: ** containing the tokenizer arguments, if any, specified following the
12868: ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12869: ** to create the FTS5 table.
12870: **
12871: ** The final argument is an output variable. If successful, (*ppOut)
12872: ** should be set to point to the new tokenizer handle and SQLITE_OK
12873: ** returned. If an error occurs, some value other than SQLITE_OK should
12874: ** be returned. In this case, fts5 assumes that the final value of *ppOut
12875: ** is undefined.
12876: **
12877: ** xDelete:
12878: ** This function is invoked to delete a tokenizer handle previously
12879: ** allocated using xCreate(). Fts5 guarantees that this function will
12880: ** be invoked exactly once for each successful call to xCreate().
12881: **
12882: ** xTokenize:
12883: ** This function is expected to tokenize the nText byte string indicated
12884: ** by argument pText. pText may or may not be nul-terminated. The first
12885: ** argument passed to this function is a pointer to an Fts5Tokenizer object
12886: ** returned by an earlier call to xCreate().
12887: **
12888: ** The second argument indicates the reason that FTS5 is requesting
12889: ** tokenization of the supplied text. This is always one of the following
12890: ** four values:
12891: **
12892: ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12893: ** or removed from the FTS table. The tokenizer is being invoked to
12894: ** determine the set of tokens to add to (or delete from) the
12895: ** FTS index.
12896: **
12897: ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12898: ** against the FTS index. The tokenizer is being called to tokenize
12899: ** a bareword or quoted string specified as part of the query.
12900: **
12901: ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12902: ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12903: ** followed by a "*" character, indicating that the last token
12904: ** returned by the tokenizer will be treated as a token prefix.
12905: **
12906: ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12907: ** satisfy an fts5_api.xTokenize() request made by an auxiliary
12908: ** function. Or an fts5_api.xColumnSize() request made by the same
12909: ** on a columnsize=0 database.
12910: ** </ul>
12911: **
12912: ** For each token in the input string, the supplied callback xToken() must
12913: ** be invoked. The first argument to it should be a copy of the pointer
12914: ** passed as the second argument to xTokenize(). The third and fourth
12915: ** arguments are a pointer to a buffer containing the token text, and the
12916: ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12917: ** of the first byte of and first byte immediately following the text from
12918: ** which the token is derived within the input.
12919: **
12920: ** The second argument passed to the xToken() callback ("tflags") should
12921: ** normally be set to 0. The exception is if the tokenizer supports
12922: ** synonyms. In this case see the discussion below for details.
12923: **
12924: ** FTS5 assumes the xToken() callback is invoked for each token in the
12925: ** order that they occur within the input text.
12926: **
12927: ** If an xToken() callback returns any value other than SQLITE_OK, then
12928: ** the tokenization should be abandoned and the xTokenize() method should
12929: ** immediately return a copy of the xToken() return value. Or, if the
12930: ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12931: ** if an error occurs with the xTokenize() implementation itself, it
12932: ** may abandon the tokenization and return any error code other than
12933: ** SQLITE_OK or SQLITE_DONE.
12934: **
12935: ** SYNONYM SUPPORT
12936: **
12937: ** Custom tokenizers may also support synonyms. Consider a case in which a
12938: ** user wishes to query for a phrase such as "first place". Using the
12939: ** built-in tokenizers, the FTS5 query 'first + place' will match instances
12940: ** of "first place" within the document set, but not alternative forms
12941: ** such as "1st place". In some applications, it would be better to match
12942: ** all instances of "first place" or "1st place" regardless of which form
12943: ** the user specified in the MATCH query text.
12944: **
12945: ** There are several ways to approach this in FTS5:
12946: **
12947: ** <ol><li> By mapping all synonyms to a single token. In this case, using
12948: ** the above example, this means that the tokenizer returns the
12949: ** same token for inputs "first" and "1st". Say that token is in
12950: ** fact "first", so that when the user inserts the document "I won
12951: ** 1st place" entries are added to the index for tokens "i", "won",
12952: ** "first" and "place". If the user then queries for '1st + place',
12953: ** the tokenizer substitutes "first" for "1st" and the query works
12954: ** as expected.
12955: **
12956: ** <li> By querying the index for all synonyms of each query term
12957: ** separately. In this case, when tokenizing query text, the
12958: ** tokenizer may provide multiple synonyms for a single term
12959: ** within the document. FTS5 then queries the index for each
12960: ** synonym individually. For example, faced with the query:
12961: **
12962: ** <codeblock>
12963: ** ... MATCH 'first place'</codeblock>
12964: **
12965: ** the tokenizer offers both "1st" and "first" as synonyms for the
12966: ** first token in the MATCH query and FTS5 effectively runs a query
12967: ** similar to:
12968: **
12969: ** <codeblock>
12970: ** ... MATCH '(first OR 1st) place'</codeblock>
12971: **
12972: ** except that, for the purposes of auxiliary functions, the query
12973: ** still appears to contain just two phrases - "(first OR 1st)"
12974: ** being treated as a single phrase.
12975: **
12976: ** <li> By adding multiple synonyms for a single term to the FTS index.
12977: ** Using this method, when tokenizing document text, the tokenizer
12978: ** provides multiple synonyms for each token. So that when a
12979: ** document such as "I won first place" is tokenized, entries are
12980: ** added to the FTS index for "i", "won", "first", "1st" and
12981: ** "place".
12982: **
12983: ** This way, even if the tokenizer does not provide synonyms
12984: ** when tokenizing query text (it should not - to do so would be
12985: ** inefficient), it doesn't matter if the user queries for
12986: ** 'first + place' or '1st + place', as there are entries in the
12987: ** FTS index corresponding to both forms of the first token.
12988: ** </ol>
12989: **
12990: ** Whether it is parsing document or query text, any call to xToken that
12991: ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12992: ** is considered to supply a synonym for the previous token. For example,
12993: ** when parsing the document "I won first place", a tokenizer that supports
12994: ** synonyms would call xToken() 5 times, as follows:
12995: **
12996: ** <codeblock>
12997: ** xToken(pCtx, 0, "i", 1, 0, 1);
12998: ** xToken(pCtx, 0, "won", 3, 2, 5);
12999: ** xToken(pCtx, 0, "first", 5, 6, 11);
13000: ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13001: ** xToken(pCtx, 0, "place", 5, 12, 17);
13002: **</codeblock>
13003: **
13004: ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13005: ** xToken() is called. Multiple synonyms may be specified for a single token
13006: ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13007: ** There is no limit to the number of synonyms that may be provided for a
13008: ** single token.
13009: **
13010: ** In many cases, method (1) above is the best approach. It does not add
13011: ** extra data to the FTS index or require FTS5 to query for multiple terms,
13012: ** so it is efficient in terms of disk space and query speed. However, it
13013: ** does not support prefix queries very well. If, as suggested above, the
13014: ** token "first" is substituted for "1st" by the tokenizer, then the query:
13015: **
13016: ** <codeblock>
13017: ** ... MATCH '1s*'</codeblock>
13018: **
13019: ** will not match documents that contain the token "1st" (as the tokenizer
13020: ** will probably not map "1s" to any prefix of "first").
13021: **
13022: ** For full prefix support, method (3) may be preferred. In this case,
13023: ** because the index contains entries for both "first" and "1st", prefix
13024: ** queries such as 'fi*' or '1s*' will match correctly. However, because
13025: ** extra entries are added to the FTS index, this method uses more space
13026: ** within the database.
13027: **
13028: ** Method (2) offers a midpoint between (1) and (3). Using this method,
13029: ** a query such as '1s*' will match documents that contain the literal
13030: ** token "1st", but not "first" (assuming the tokenizer is not able to
13031: ** provide synonyms for prefixes). However, a non-prefix query like '1st'
13032: ** will match against "1st" and "first". This method does not require
13033: ** extra disk space, as no extra entries are added to the FTS index.
13034: ** On the other hand, it may require more CPU cycles to run MATCH queries,
13035: ** as separate queries of the FTS index are required for each synonym.
13036: **
13037: ** When using methods (2) or (3), it is important that the tokenizer only
13038: ** provide synonyms when tokenizing document text (method (3)) or query
13039: ** text (method (2)), not both. Doing so will not cause any errors, but is
13040: ** inefficient.
13041: */
13042: typedef struct Fts5Tokenizer Fts5Tokenizer;
13043: typedef struct fts5_tokenizer fts5_tokenizer;
13044: struct fts5_tokenizer {
13045: int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13046: void (*xDelete)(Fts5Tokenizer*);
13047: int (*xTokenize)(Fts5Tokenizer*,
13048: void *pCtx,
13049: int flags, /* Mask of FTS5_TOKENIZE_* flags */
13050: const char *pText, int nText,
13051: int (*xToken)(
13052: void *pCtx, /* Copy of 2nd argument to xTokenize() */
13053: int tflags, /* Mask of FTS5_TOKEN_* flags */
13054: const char *pToken, /* Pointer to buffer containing token */
13055: int nToken, /* Size of token in bytes */
13056: int iStart, /* Byte offset of token within input text */
13057: int iEnd /* Byte offset of end of token within input text */
13058: )
13059: );
13060: };
13061:
13062: /* Flags that may be passed as the third argument to xTokenize() */
13063: #define FTS5_TOKENIZE_QUERY 0x0001
13064: #define FTS5_TOKENIZE_PREFIX 0x0002
13065: #define FTS5_TOKENIZE_DOCUMENT 0x0004
13066: #define FTS5_TOKENIZE_AUX 0x0008
13067:
13068: /* Flags that may be passed by the tokenizer implementation back to FTS5
13069: ** as the third argument to the supplied xToken callback. */
13070: #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13071:
13072: /*
13073: ** END OF CUSTOM TOKENIZERS
13074: *************************************************************************/
13075:
13076: /*************************************************************************
13077: ** FTS5 EXTENSION REGISTRATION API
13078: */
13079: typedef struct fts5_api fts5_api;
13080: struct fts5_api {
13081: int iVersion; /* Currently always set to 2 */
13082:
13083: /* Create a new tokenizer */
13084: int (*xCreateTokenizer)(
13085: fts5_api *pApi,
13086: const char *zName,
13087: void *pUserData,
13088: fts5_tokenizer *pTokenizer,
13089: void (*xDestroy)(void*)
13090: );
13091:
13092: /* Find an existing tokenizer */
13093: int (*xFindTokenizer)(
13094: fts5_api *pApi,
13095: const char *zName,
13096: void **ppUserData,
13097: fts5_tokenizer *pTokenizer
13098: );
13099:
13100: /* Create a new auxiliary function */
13101: int (*xCreateFunction)(
13102: fts5_api *pApi,
13103: const char *zName,
13104: void *pUserData,
13105: fts5_extension_function xFunction,
13106: void (*xDestroy)(void*)
13107: );
13108: };
13109:
13110: /*
13111: ** END OF REGISTRATION API
13112: *************************************************************************/
13113:
13114: #ifdef __cplusplus
13115: } /* end of the 'extern "C"' block */
13116: #endif
13117:
13118: #endif /* _FTS5_H */
13119:
13120: /******** End of fts5.h *********/
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