Annotation of elwix/files/sqlite/dist/sqlite3.h, revision 1.6
1.2 misho 1: /*
1.5 misho 2: ** 2001-09-15
1.2 misho 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
1.4 misho 26: ** on how SQLite interfaces are supposed to operate.
1.2 misho 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: */
1.4 misho 33: #ifndef SQLITE3_H
34: #define SQLITE3_H
1.2 misho 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: /*
1.4 misho 46: ** Provide the ability to override linkage features of the interface.
1.2 misho 47: */
48: #ifndef SQLITE_EXTERN
49: # define SQLITE_EXTERN extern
50: #endif
51: #ifndef SQLITE_API
52: # define SQLITE_API
53: #endif
1.4 misho 54: #ifndef SQLITE_CDECL
55: # define SQLITE_CDECL
56: #endif
57: #ifndef SQLITE_APICALL
58: # define SQLITE_APICALL
59: #endif
60: #ifndef SQLITE_STDCALL
61: # define SQLITE_STDCALL SQLITE_APICALL
62: #endif
63: #ifndef SQLITE_CALLBACK
64: # define SQLITE_CALLBACK
65: #endif
66: #ifndef SQLITE_SYSAPI
67: # define SQLITE_SYSAPI
68: #endif
1.2 misho 69:
70: /*
71: ** These no-op macros are used in front of interfaces to mark those
72: ** interfaces as either deprecated or experimental. New applications
1.4 misho 73: ** should not use deprecated interfaces - they are supported for backwards
1.2 misho 74: ** compatibility only. Application writers should be aware that
75: ** experimental interfaces are subject to change in point releases.
76: **
77: ** These macros used to resolve to various kinds of compiler magic that
78: ** would generate warning messages when they were used. But that
79: ** compiler magic ended up generating such a flurry of bug reports
80: ** that we have taken it all out and gone back to using simple
81: ** noop macros.
82: */
83: #define SQLITE_DEPRECATED
84: #define SQLITE_EXPERIMENTAL
85:
86: /*
87: ** Ensure these symbols were not defined by some previous header file.
88: */
89: #ifdef SQLITE_VERSION
90: # undef SQLITE_VERSION
91: #endif
92: #ifdef SQLITE_VERSION_NUMBER
93: # undef SQLITE_VERSION_NUMBER
94: #endif
95:
96: /*
97: ** CAPI3REF: Compile-Time Library Version Numbers
98: **
99: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100: ** evaluates to a string literal that is the SQLite version in the
101: ** format "X.Y.Z" where X is the major version number (always 3 for
102: ** SQLite3) and Y is the minor version number and Z is the release number.)^
103: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105: ** numbers used in [SQLITE_VERSION].)^
106: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107: ** be larger than the release from which it is derived. Either Y will
108: ** be held constant and Z will be incremented or else Y will be incremented
109: ** and Z will be reset to zero.
110: **
1.5 misho 111: ** Since [version 3.6.18] ([dateof:3.6.18]),
112: ** SQLite source code has been stored in the
1.2 misho 113: ** <a href="http://www.fossil-scm.org/">Fossil configuration management
114: ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115: ** a string which identifies a particular check-in of SQLite
116: ** within its configuration management system. ^The SQLITE_SOURCE_ID
1.5 misho 117: ** string contains the date and time of the check-in (UTC) and a SHA1
118: ** or SHA3-256 hash of the entire source tree. If the source code has
119: ** been edited in any way since it was last checked in, then the last
120: ** four hexadecimal digits of the hash may be modified.
1.2 misho 121: **
122: ** See also: [sqlite3_libversion()],
123: ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124: ** [sqlite_version()] and [sqlite_source_id()].
125: */
1.6 ! misho 126: #define SQLITE_VERSION "3.35.1"
! 127: #define SQLITE_VERSION_NUMBER 3035001
! 128: #define SQLITE_SOURCE_ID "2021-03-15 16:53:57 aea12399bf1fdc76af43499d4624c3afa17c3e6c2459b71c195804bb98def66a"
1.2 misho 129:
130: /*
131: ** CAPI3REF: Run-Time Library Version Numbers
1.5 misho 132: ** KEYWORDS: sqlite3_version sqlite3_sourceid
1.2 misho 133: **
134: ** These interfaces provide the same information as the [SQLITE_VERSION],
135: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136: ** but are associated with the library instead of the header file. ^(Cautious
137: ** programmers might include assert() statements in their application to
138: ** verify that values returned by these interfaces match the macros in
1.4 misho 139: ** the header, and thus ensure that the application is
1.2 misho 140: ** compiled with matching library and header files.
141: **
142: ** <blockquote><pre>
143: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
1.5 misho 144: ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
1.2 misho 145: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146: ** </pre></blockquote>)^
147: **
148: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149: ** macro. ^The sqlite3_libversion() function returns a pointer to the
150: ** to the sqlite3_version[] string constant. The sqlite3_libversion()
151: ** function is provided for use in DLLs since DLL users usually do not have
152: ** direct access to string constants within the DLL. ^The
153: ** sqlite3_libversion_number() function returns an integer equal to
1.5 misho 154: ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155: ** a pointer to a string constant whose value is the same as the
156: ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157: ** using an edited copy of [the amalgamation], then the last four characters
158: ** of the hash might be different from [SQLITE_SOURCE_ID].)^
1.2 misho 159: **
160: ** See also: [sqlite_version()] and [sqlite_source_id()].
161: */
162: SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163: SQLITE_API const char *sqlite3_libversion(void);
164: SQLITE_API const char *sqlite3_sourceid(void);
165: SQLITE_API int sqlite3_libversion_number(void);
166:
167: /*
168: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
169: **
1.5 misho 170: ** ^The sqlite3_compileoption_used() function returns 0 or 1
171: ** indicating whether the specified option was defined at
172: ** compile time. ^The SQLITE_ prefix may be omitted from the
173: ** option name passed to sqlite3_compileoption_used().
1.2 misho 174: **
175: ** ^The sqlite3_compileoption_get() function allows iterating
176: ** over the list of options that were defined at compile time by
177: ** returning the N-th compile time option string. ^If N is out of range,
1.5 misho 178: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179: ** prefix is omitted from any strings returned by
1.2 misho 180: ** sqlite3_compileoption_get().
181: **
182: ** ^Support for the diagnostic functions sqlite3_compileoption_used()
1.5 misho 183: ** and sqlite3_compileoption_get() may be omitted by specifying the
1.2 misho 184: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
185: **
186: ** See also: SQL functions [sqlite_compileoption_used()] and
187: ** [sqlite_compileoption_get()] and the [compile_options pragma].
188: */
189: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190: SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191: SQLITE_API const char *sqlite3_compileoption_get(int N);
1.5 misho 192: #else
193: # define sqlite3_compileoption_used(X) 0
194: # define sqlite3_compileoption_get(X) ((void*)0)
1.2 misho 195: #endif
196:
197: /*
198: ** CAPI3REF: Test To See If The Library Is Threadsafe
199: **
200: ** ^The sqlite3_threadsafe() function returns zero if and only if
201: ** SQLite was compiled with mutexing code omitted due to the
202: ** [SQLITE_THREADSAFE] compile-time option being set to 0.
203: **
204: ** SQLite can be compiled with or without mutexes. When
205: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
206: ** are enabled and SQLite is threadsafe. When the
1.5 misho 207: ** [SQLITE_THREADSAFE] macro is 0,
1.2 misho 208: ** the mutexes are omitted. Without the mutexes, it is not safe
209: ** to use SQLite concurrently from more than one thread.
210: **
211: ** Enabling mutexes incurs a measurable performance penalty.
212: ** So if speed is of utmost importance, it makes sense to disable
213: ** the mutexes. But for maximum safety, mutexes should be enabled.
214: ** ^The default behavior is for mutexes to be enabled.
215: **
216: ** This interface can be used by an application to make sure that the
217: ** version of SQLite that it is linking against was compiled with
218: ** the desired setting of the [SQLITE_THREADSAFE] macro.
219: **
220: ** This interface only reports on the compile-time mutex setting
221: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
222: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
223: ** can be fully or partially disabled using a call to [sqlite3_config()]
224: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
1.4 misho 225: ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
1.2 misho 226: ** sqlite3_threadsafe() function shows only the compile-time setting of
227: ** thread safety, not any run-time changes to that setting made by
228: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
229: ** is unchanged by calls to sqlite3_config().)^
230: **
231: ** See the [threading mode] documentation for additional information.
232: */
233: SQLITE_API int sqlite3_threadsafe(void);
234:
235: /*
236: ** CAPI3REF: Database Connection Handle
237: ** KEYWORDS: {database connection} {database connections}
238: **
239: ** Each open SQLite database is represented by a pointer to an instance of
240: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
241: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
242: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
1.3 misho 243: ** and [sqlite3_close_v2()] are its destructors. There are many other
244: ** interfaces (such as
1.2 misho 245: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
246: ** [sqlite3_busy_timeout()] to name but three) that are methods on an
247: ** sqlite3 object.
248: */
249: typedef struct sqlite3 sqlite3;
250:
251: /*
252: ** CAPI3REF: 64-Bit Integer Types
253: ** KEYWORDS: sqlite_int64 sqlite_uint64
254: **
255: ** Because there is no cross-platform way to specify 64-bit integer types
256: ** SQLite includes typedefs for 64-bit signed and unsigned integers.
257: **
258: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
259: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
260: ** compatibility only.
261: **
262: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
263: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
1.5 misho 264: ** sqlite3_uint64 and sqlite_uint64 types can store integer values
1.2 misho 265: ** between 0 and +18446744073709551615 inclusive.
266: */
267: #ifdef SQLITE_INT64_TYPE
268: typedef SQLITE_INT64_TYPE sqlite_int64;
1.5 misho 269: # ifdef SQLITE_UINT64_TYPE
270: typedef SQLITE_UINT64_TYPE sqlite_uint64;
271: # else
272: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
273: # endif
1.2 misho 274: #elif defined(_MSC_VER) || defined(__BORLANDC__)
275: typedef __int64 sqlite_int64;
276: typedef unsigned __int64 sqlite_uint64;
277: #else
278: typedef long long int sqlite_int64;
279: typedef unsigned long long int sqlite_uint64;
280: #endif
281: typedef sqlite_int64 sqlite3_int64;
282: typedef sqlite_uint64 sqlite3_uint64;
283:
284: /*
285: ** If compiling for a processor that lacks floating point support,
286: ** substitute integer for floating-point.
287: */
288: #ifdef SQLITE_OMIT_FLOATING_POINT
289: # define double sqlite3_int64
290: #endif
291:
292: /*
293: ** CAPI3REF: Closing A Database Connection
1.4 misho 294: ** DESTRUCTOR: sqlite3
1.2 misho 295: **
1.3 misho 296: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
297: ** for the [sqlite3] object.
1.4 misho 298: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
1.3 misho 299: ** the [sqlite3] object is successfully destroyed and all associated
300: ** resources are deallocated.
301: **
1.5 misho 302: ** Ideally, applications should [sqlite3_finalize | finalize] all
303: ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
304: ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
305: ** with the [sqlite3] object prior to attempting to close the object.
1.3 misho 306: ** ^If the database connection is associated with unfinalized prepared
1.5 misho 307: ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
308: ** sqlite3_close() will leave the database connection open and return
309: ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
310: ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
311: ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
312: ** connection immediately, it marks the database connection as an unusable
313: ** "zombie" and makes arrangements to automatically deallocate the database
314: ** connection after all prepared statements are finalized, all BLOB handles
315: ** are closed, and all backups have finished. The sqlite3_close_v2() interface
316: ** is intended for use with host languages that are garbage collected, and
317: ** where the order in which destructors are called is arbitrary.
1.2 misho 318: **
1.3 misho 319: ** ^If an [sqlite3] object is destroyed while a transaction is open,
1.2 misho 320: ** the transaction is automatically rolled back.
321: **
1.3 misho 322: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
323: ** must be either a NULL
1.2 misho 324: ** pointer or an [sqlite3] object pointer obtained
325: ** from [sqlite3_open()], [sqlite3_open16()], or
326: ** [sqlite3_open_v2()], and not previously closed.
1.3 misho 327: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
328: ** argument is a harmless no-op.
1.2 misho 329: */
1.3 misho 330: SQLITE_API int sqlite3_close(sqlite3*);
331: SQLITE_API int sqlite3_close_v2(sqlite3*);
1.2 misho 332:
333: /*
334: ** The type for a callback function.
335: ** This is legacy and deprecated. It is included for historical
336: ** compatibility and is not documented.
337: */
338: typedef int (*sqlite3_callback)(void*,int,char**, char**);
339:
340: /*
341: ** CAPI3REF: One-Step Query Execution Interface
1.4 misho 342: ** METHOD: sqlite3
1.2 misho 343: **
344: ** The sqlite3_exec() interface is a convenience wrapper around
345: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
346: ** that allows an application to run multiple statements of SQL
1.5 misho 347: ** without having to use a lot of C code.
1.2 misho 348: **
349: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
350: ** semicolon-separate SQL statements passed into its 2nd argument,
351: ** in the context of the [database connection] passed in as its 1st
352: ** argument. ^If the callback function of the 3rd argument to
353: ** sqlite3_exec() is not NULL, then it is invoked for each result row
354: ** coming out of the evaluated SQL statements. ^The 4th argument to
355: ** sqlite3_exec() is relayed through to the 1st argument of each
356: ** callback invocation. ^If the callback pointer to sqlite3_exec()
357: ** is NULL, then no callback is ever invoked and result rows are
358: ** ignored.
359: **
360: ** ^If an error occurs while evaluating the SQL statements passed into
361: ** sqlite3_exec(), then execution of the current statement stops and
362: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
363: ** is not NULL then any error message is written into memory obtained
364: ** from [sqlite3_malloc()] and passed back through the 5th parameter.
365: ** To avoid memory leaks, the application should invoke [sqlite3_free()]
366: ** on error message strings returned through the 5th parameter of
1.4 misho 367: ** sqlite3_exec() after the error message string is no longer needed.
1.2 misho 368: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
369: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
370: ** NULL before returning.
371: **
372: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
373: ** routine returns SQLITE_ABORT without invoking the callback again and
374: ** without running any subsequent SQL statements.
375: **
376: ** ^The 2nd argument to the sqlite3_exec() callback function is the
377: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
378: ** callback is an array of pointers to strings obtained as if from
379: ** [sqlite3_column_text()], one for each column. ^If an element of a
380: ** result row is NULL then the corresponding string pointer for the
381: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
382: ** sqlite3_exec() callback is an array of pointers to strings where each
383: ** entry represents the name of corresponding result column as obtained
384: ** from [sqlite3_column_name()].
385: **
386: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
1.5 misho 387: ** to an empty string, or a pointer that contains only whitespace and/or
1.2 misho 388: ** SQL comments, then no SQL statements are evaluated and the database
389: ** is not changed.
390: **
391: ** Restrictions:
392: **
393: ** <ul>
1.4 misho 394: ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
1.2 misho 395: ** is a valid and open [database connection].
1.4 misho 396: ** <li> The application must not close the [database connection] specified by
1.2 misho 397: ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
398: ** <li> The application must not modify the SQL statement text passed into
399: ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
400: ** </ul>
401: */
402: SQLITE_API int sqlite3_exec(
403: sqlite3*, /* An open database */
404: const char *sql, /* SQL to be evaluated */
405: int (*callback)(void*,int,char**,char**), /* Callback function */
406: void *, /* 1st argument to callback */
407: char **errmsg /* Error msg written here */
408: );
409:
410: /*
411: ** CAPI3REF: Result Codes
1.4 misho 412: ** KEYWORDS: {result code definitions}
1.2 misho 413: **
414: ** Many SQLite functions return an integer result code from the set shown
415: ** here in order to indicate success or failure.
416: **
417: ** New error codes may be added in future versions of SQLite.
418: **
1.4 misho 419: ** See also: [extended result code definitions]
1.2 misho 420: */
421: #define SQLITE_OK 0 /* Successful result */
422: /* beginning-of-error-codes */
1.5 misho 423: #define SQLITE_ERROR 1 /* Generic error */
1.2 misho 424: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
425: #define SQLITE_PERM 3 /* Access permission denied */
426: #define SQLITE_ABORT 4 /* Callback routine requested an abort */
427: #define SQLITE_BUSY 5 /* The database file is locked */
428: #define SQLITE_LOCKED 6 /* A table in the database is locked */
429: #define SQLITE_NOMEM 7 /* A malloc() failed */
430: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
431: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
432: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
433: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
434: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
435: #define SQLITE_FULL 13 /* Insertion failed because database is full */
436: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
437: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
1.5 misho 438: #define SQLITE_EMPTY 16 /* Internal use only */
1.2 misho 439: #define SQLITE_SCHEMA 17 /* The database schema changed */
440: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
441: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
442: #define SQLITE_MISMATCH 20 /* Data type mismatch */
443: #define SQLITE_MISUSE 21 /* Library used incorrectly */
444: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
445: #define SQLITE_AUTH 23 /* Authorization denied */
1.5 misho 446: #define SQLITE_FORMAT 24 /* Not used */
1.2 misho 447: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
448: #define SQLITE_NOTADB 26 /* File opened that is not a database file */
1.4 misho 449: #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
450: #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
1.2 misho 451: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
452: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
453: /* end-of-error-codes */
454:
455: /*
456: ** CAPI3REF: Extended Result Codes
1.4 misho 457: ** KEYWORDS: {extended result code definitions}
1.2 misho 458: **
1.4 misho 459: ** In its default configuration, SQLite API routines return one of 30 integer
460: ** [result codes]. However, experience has shown that many of
1.2 misho 461: ** these result codes are too coarse-grained. They do not provide as
462: ** much information about problems as programmers might like. In an effort to
1.5 misho 463: ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
464: ** and later) include
1.2 misho 465: ** support for additional result codes that provide more detailed information
1.4 misho 466: ** about errors. These [extended result codes] are enabled or disabled
1.2 misho 467: ** on a per database connection basis using the
1.4 misho 468: ** [sqlite3_extended_result_codes()] API. Or, the extended code for
469: ** the most recent error can be obtained using
470: ** [sqlite3_extended_errcode()].
1.2 misho 471: */
1.5 misho 472: #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
473: #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
474: #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
1.2 misho 475: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
476: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
477: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
478: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
479: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
480: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
481: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
482: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
483: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
484: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
485: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
486: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
487: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
488: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
489: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
490: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
491: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
492: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
493: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
494: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
495: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
496: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
1.3 misho 497: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
1.4 misho 498: #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
499: #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
500: #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
501: #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
502: #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
1.5 misho 503: #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
504: #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
505: #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
506: #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
1.6 ! misho 507: #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
1.2 misho 508: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
1.5 misho 509: #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
1.2 misho 510: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
1.4 misho 511: #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
1.5 misho 512: #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
1.2 misho 513: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
1.3 misho 514: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
515: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
1.4 misho 516: #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
1.5 misho 517: #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
518: #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
1.2 misho 519: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
1.5 misho 520: #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
521: #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
1.2 misho 522: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
523: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
1.4 misho 524: #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
525: #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
1.5 misho 526: #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
527: #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
1.3 misho 528: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
1.4 misho 529: #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
530: #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
531: #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
532: #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
533: #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
534: #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
535: #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
536: #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
537: #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
538: #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
1.5 misho 539: #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
1.4 misho 540: #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
541: #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
542: #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
543: #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
544: #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
1.5 misho 545: #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8))
1.2 misho 546:
547: /*
548: ** CAPI3REF: Flags For File Open Operations
549: **
550: ** These bit values are intended for use in the
551: ** 3rd parameter to the [sqlite3_open_v2()] interface and
552: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
553: */
554: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
555: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
556: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
557: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
558: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
559: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
560: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
1.3 misho 561: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
1.2 misho 562: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
563: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
564: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
565: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
566: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
567: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
1.5 misho 568: #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
1.2 misho 569: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
570: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
571: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
572: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
573: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
1.5 misho 574: #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
1.2 misho 575:
576: /* Reserved: 0x00F00000 */
1.5 misho 577: /* Legacy compatibility: */
578: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
579:
1.2 misho 580:
581: /*
582: ** CAPI3REF: Device Characteristics
583: **
584: ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
1.3 misho 585: ** object returns an integer which is a vector of these
1.2 misho 586: ** bit values expressing I/O characteristics of the mass storage
587: ** device that holds the file that the [sqlite3_io_methods]
588: ** refers to.
589: **
590: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
591: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
592: ** mean that writes of blocks that are nnn bytes in size and
593: ** are aligned to an address which is an integer multiple of
594: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
595: ** that when data is appended to a file, the data is appended
596: ** first then the size of the file is extended, never the other
597: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
598: ** information is written to disk in the same order as calls
599: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
600: ** after reboot following a crash or power loss, the only bytes in a
601: ** file that were written at the application level might have changed
602: ** and that adjacent bytes, even bytes within the same sector are
1.4 misho 603: ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
1.5 misho 604: ** flag indicates that a file cannot be deleted when open. The
1.4 misho 605: ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
606: ** read-only media and cannot be changed even by processes with
607: ** elevated privileges.
1.5 misho 608: **
609: ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
610: ** filesystem supports doing multiple write operations atomically when those
611: ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
612: ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
1.2 misho 613: */
614: #define SQLITE_IOCAP_ATOMIC 0x00000001
615: #define SQLITE_IOCAP_ATOMIC512 0x00000002
616: #define SQLITE_IOCAP_ATOMIC1K 0x00000004
617: #define SQLITE_IOCAP_ATOMIC2K 0x00000008
618: #define SQLITE_IOCAP_ATOMIC4K 0x00000010
619: #define SQLITE_IOCAP_ATOMIC8K 0x00000020
620: #define SQLITE_IOCAP_ATOMIC16K 0x00000040
621: #define SQLITE_IOCAP_ATOMIC32K 0x00000080
622: #define SQLITE_IOCAP_ATOMIC64K 0x00000100
623: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
624: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
625: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
626: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
1.4 misho 627: #define SQLITE_IOCAP_IMMUTABLE 0x00002000
1.5 misho 628: #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
1.2 misho 629:
630: /*
631: ** CAPI3REF: File Locking Levels
632: **
633: ** SQLite uses one of these integer values as the second
634: ** argument to calls it makes to the xLock() and xUnlock() methods
635: ** of an [sqlite3_io_methods] object.
636: */
637: #define SQLITE_LOCK_NONE 0
638: #define SQLITE_LOCK_SHARED 1
639: #define SQLITE_LOCK_RESERVED 2
640: #define SQLITE_LOCK_PENDING 3
641: #define SQLITE_LOCK_EXCLUSIVE 4
642:
643: /*
644: ** CAPI3REF: Synchronization Type Flags
645: **
646: ** When SQLite invokes the xSync() method of an
647: ** [sqlite3_io_methods] object it uses a combination of
648: ** these integer values as the second argument.
649: **
650: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
651: ** sync operation only needs to flush data to mass storage. Inode
652: ** information need not be flushed. If the lower four bits of the flag
653: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
654: ** If the lower four bits equal SQLITE_SYNC_FULL, that means
655: ** to use Mac OS X style fullsync instead of fsync().
656: **
657: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
658: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
659: ** settings. The [synchronous pragma] determines when calls to the
660: ** xSync VFS method occur and applies uniformly across all platforms.
661: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
662: ** energetic or rigorous or forceful the sync operations are and
663: ** only make a difference on Mac OSX for the default SQLite code.
664: ** (Third-party VFS implementations might also make the distinction
665: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
666: ** operating systems natively supported by SQLite, only Mac OSX
667: ** cares about the difference.)
668: */
669: #define SQLITE_SYNC_NORMAL 0x00002
670: #define SQLITE_SYNC_FULL 0x00003
671: #define SQLITE_SYNC_DATAONLY 0x00010
672:
673: /*
674: ** CAPI3REF: OS Interface Open File Handle
675: **
1.5 misho 676: ** An [sqlite3_file] object represents an open file in the
1.2 misho 677: ** [sqlite3_vfs | OS interface layer]. Individual OS interface
678: ** implementations will
679: ** want to subclass this object by appending additional fields
680: ** for their own use. The pMethods entry is a pointer to an
681: ** [sqlite3_io_methods] object that defines methods for performing
682: ** I/O operations on the open file.
683: */
684: typedef struct sqlite3_file sqlite3_file;
685: struct sqlite3_file {
686: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
687: };
688:
689: /*
690: ** CAPI3REF: OS Interface File Virtual Methods Object
691: **
692: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
693: ** [sqlite3_file] object (or, more commonly, a subclass of the
694: ** [sqlite3_file] object) with a pointer to an instance of this object.
695: ** This object defines the methods used to perform various operations
696: ** against the open file represented by the [sqlite3_file] object.
697: **
1.5 misho 698: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
1.2 misho 699: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
700: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
701: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
702: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
703: ** to NULL.
704: **
705: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
706: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
707: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
708: ** flag may be ORed in to indicate that only the data of the file
709: ** and not its inode needs to be synced.
710: **
711: ** The integer values to xLock() and xUnlock() are one of
712: ** <ul>
713: ** <li> [SQLITE_LOCK_NONE],
714: ** <li> [SQLITE_LOCK_SHARED],
715: ** <li> [SQLITE_LOCK_RESERVED],
716: ** <li> [SQLITE_LOCK_PENDING], or
717: ** <li> [SQLITE_LOCK_EXCLUSIVE].
718: ** </ul>
719: ** xLock() increases the lock. xUnlock() decreases the lock.
720: ** The xCheckReservedLock() method checks whether any database connection,
721: ** either in this process or in some other process, is holding a RESERVED,
722: ** PENDING, or EXCLUSIVE lock on the file. It returns true
723: ** if such a lock exists and false otherwise.
724: **
725: ** The xFileControl() method is a generic interface that allows custom
726: ** VFS implementations to directly control an open file using the
727: ** [sqlite3_file_control()] interface. The second "op" argument is an
728: ** integer opcode. The third argument is a generic pointer intended to
729: ** point to a structure that may contain arguments or space in which to
730: ** write return values. Potential uses for xFileControl() might be
731: ** functions to enable blocking locks with timeouts, to change the
732: ** locking strategy (for example to use dot-file locks), to inquire
733: ** about the status of a lock, or to break stale locks. The SQLite
734: ** core reserves all opcodes less than 100 for its own use.
1.4 misho 735: ** A [file control opcodes | list of opcodes] less than 100 is available.
1.2 misho 736: ** Applications that define a custom xFileControl method should use opcodes
737: ** greater than 100 to avoid conflicts. VFS implementations should
738: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
739: ** recognize.
740: **
741: ** The xSectorSize() method returns the sector size of the
742: ** device that underlies the file. The sector size is the
743: ** minimum write that can be performed without disturbing
744: ** other bytes in the file. The xDeviceCharacteristics()
745: ** method returns a bit vector describing behaviors of the
746: ** underlying device:
747: **
748: ** <ul>
749: ** <li> [SQLITE_IOCAP_ATOMIC]
750: ** <li> [SQLITE_IOCAP_ATOMIC512]
751: ** <li> [SQLITE_IOCAP_ATOMIC1K]
752: ** <li> [SQLITE_IOCAP_ATOMIC2K]
753: ** <li> [SQLITE_IOCAP_ATOMIC4K]
754: ** <li> [SQLITE_IOCAP_ATOMIC8K]
755: ** <li> [SQLITE_IOCAP_ATOMIC16K]
756: ** <li> [SQLITE_IOCAP_ATOMIC32K]
757: ** <li> [SQLITE_IOCAP_ATOMIC64K]
758: ** <li> [SQLITE_IOCAP_SAFE_APPEND]
759: ** <li> [SQLITE_IOCAP_SEQUENTIAL]
1.5 misho 760: ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
761: ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
762: ** <li> [SQLITE_IOCAP_IMMUTABLE]
763: ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
1.2 misho 764: ** </ul>
765: **
766: ** The SQLITE_IOCAP_ATOMIC property means that all writes of
767: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
768: ** mean that writes of blocks that are nnn bytes in size and
769: ** are aligned to an address which is an integer multiple of
770: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
771: ** that when data is appended to a file, the data is appended
772: ** first then the size of the file is extended, never the other
773: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
774: ** information is written to disk in the same order as calls
775: ** to xWrite().
776: **
777: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
778: ** in the unread portions of the buffer with zeros. A VFS that
779: ** fails to zero-fill short reads might seem to work. However,
780: ** failure to zero-fill short reads will eventually lead to
781: ** database corruption.
782: */
783: typedef struct sqlite3_io_methods sqlite3_io_methods;
784: struct sqlite3_io_methods {
785: int iVersion;
786: int (*xClose)(sqlite3_file*);
787: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
788: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
789: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
790: int (*xSync)(sqlite3_file*, int flags);
791: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
792: int (*xLock)(sqlite3_file*, int);
793: int (*xUnlock)(sqlite3_file*, int);
794: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
795: int (*xFileControl)(sqlite3_file*, int op, void *pArg);
796: int (*xSectorSize)(sqlite3_file*);
797: int (*xDeviceCharacteristics)(sqlite3_file*);
798: /* Methods above are valid for version 1 */
799: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
800: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
801: void (*xShmBarrier)(sqlite3_file*);
802: int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
803: /* Methods above are valid for version 2 */
1.4 misho 804: int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
805: int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
806: /* Methods above are valid for version 3 */
1.2 misho 807: /* Additional methods may be added in future releases */
808: };
809:
810: /*
811: ** CAPI3REF: Standard File Control Opcodes
1.4 misho 812: ** KEYWORDS: {file control opcodes} {file control opcode}
1.2 misho 813: **
814: ** These integer constants are opcodes for the xFileControl method
815: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
816: ** interface.
817: **
1.4 misho 818: ** <ul>
819: ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
1.2 misho 820: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
821: ** opcode causes the xFileControl method to write the current state of
822: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
823: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
824: ** into an integer that the pArg argument points to. This capability
1.4 misho 825: ** is used during testing and is only available when the SQLITE_TEST
826: ** compile-time option is used.
827: **
1.3 misho 828: ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
1.2 misho 829: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
830: ** layer a hint of how large the database file will grow to be during the
831: ** current transaction. This hint is not guaranteed to be accurate but it
832: ** is often close. The underlying VFS might choose to preallocate database
833: ** file space based on this hint in order to help writes to the database
834: ** file run faster.
835: **
1.5 misho 836: ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
837: ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
838: ** implements [sqlite3_deserialize()] to set an upper bound on the size
839: ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
840: ** If the integer pointed to is negative, then it is filled in with the
841: ** current limit. Otherwise the limit is set to the larger of the value
842: ** of the integer pointed to and the current database size. The integer
843: ** pointed to is set to the new limit.
844: **
1.3 misho 845: ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
1.2 misho 846: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
847: ** extends and truncates the database file in chunks of a size specified
1.5 misho 848: ** by the user. The fourth argument to [sqlite3_file_control()] should
1.2 misho 849: ** point to an integer (type int) containing the new chunk-size to use
850: ** for the nominated database. Allocating database file space in large
851: ** chunks (say 1MB at a time), may reduce file-system fragmentation and
852: ** improve performance on some systems.
853: **
1.3 misho 854: ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
1.2 misho 855: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
856: ** to the [sqlite3_file] object associated with a particular database
1.4 misho 857: ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
858: **
859: ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
860: ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
861: ** to the [sqlite3_file] object associated with the journal file (either
862: ** the [rollback journal] or the [write-ahead log]) for a particular database
863: ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
1.2 misho 864: **
1.3 misho 865: ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
1.4 misho 866: ** No longer in use.
867: **
868: ** <li>[[SQLITE_FCNTL_SYNC]]
869: ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
870: ** sent to the VFS immediately before the xSync method is invoked on a
1.5 misho 871: ** database file descriptor. Or, if the xSync method is not invoked
872: ** because the user has configured SQLite with
873: ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
1.4 misho 874: ** of the xSync method. In most cases, the pointer argument passed with
875: ** this file-control is NULL. However, if the database file is being synced
876: ** as part of a multi-database commit, the argument points to a nul-terminated
1.5 misho 877: ** string containing the transactions super-journal file name. VFSes that
878: ** do not need this signal should silently ignore this opcode. Applications
879: ** should not call [sqlite3_file_control()] with this opcode as doing so may
880: ** disrupt the operation of the specialized VFSes that do require it.
1.4 misho 881: **
882: ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
883: ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
884: ** and sent to the VFS after a transaction has been committed immediately
885: ** but before the database is unlocked. VFSes that do not need this signal
886: ** should silently ignore this opcode. Applications should not call
1.5 misho 887: ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
888: ** operation of the specialized VFSes that do require it.
1.2 misho 889: **
1.3 misho 890: ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
1.2 misho 891: ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
892: ** retry counts and intervals for certain disk I/O operations for the
893: ** windows [VFS] in order to provide robustness in the presence of
894: ** anti-virus programs. By default, the windows VFS will retry file read,
895: ** file write, and file delete operations up to 10 times, with a delay
896: ** of 25 milliseconds before the first retry and with the delay increasing
897: ** by an additional 25 milliseconds with each subsequent retry. This
898: ** opcode allows these two values (10 retries and 25 milliseconds of delay)
899: ** to be adjusted. The values are changed for all database connections
900: ** within the same process. The argument is a pointer to an array of two
1.5 misho 901: ** integers where the first integer is the new retry count and the second
1.2 misho 902: ** integer is the delay. If either integer is negative, then the setting
903: ** is not changed but instead the prior value of that setting is written
904: ** into the array entry, allowing the current retry settings to be
905: ** interrogated. The zDbName parameter is ignored.
906: **
1.3 misho 907: ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
1.2 misho 908: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
1.3 misho 909: ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
1.5 misho 910: ** write ahead log ([WAL file]) and shared memory
911: ** files used for transaction control
1.2 misho 912: ** are automatically deleted when the latest connection to the database
913: ** closes. Setting persistent WAL mode causes those files to persist after
914: ** close. Persisting the files is useful when other processes that do not
915: ** have write permission on the directory containing the database file want
916: ** to read the database file, as the WAL and shared memory files must exist
917: ** in order for the database to be readable. The fourth parameter to
918: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
919: ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
920: ** WAL mode. If the integer is -1, then it is overwritten with the current
921: ** WAL persistence setting.
922: **
1.3 misho 923: ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
1.2 misho 924: ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
925: ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
926: ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
927: ** xDeviceCharacteristics methods. The fourth parameter to
928: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
929: ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
930: ** mode. If the integer is -1, then it is overwritten with the current
931: ** zero-damage mode setting.
932: **
1.3 misho 933: ** <li>[[SQLITE_FCNTL_OVERWRITE]]
1.2 misho 934: ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
935: ** a write transaction to indicate that, unless it is rolled back for some
1.5 misho 936: ** reason, the entire database file will be overwritten by the current
1.2 misho 937: ** transaction. This is used by VACUUM operations.
938: **
1.3 misho 939: ** <li>[[SQLITE_FCNTL_VFSNAME]]
1.2 misho 940: ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
941: ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
1.5 misho 942: ** final bottom-level VFS are written into memory obtained from
1.2 misho 943: ** [sqlite3_malloc()] and the result is stored in the char* variable
944: ** that the fourth parameter of [sqlite3_file_control()] points to.
945: ** The caller is responsible for freeing the memory when done. As with
946: ** all file-control actions, there is no guarantee that this will actually
947: ** do anything. Callers should initialize the char* variable to a NULL
948: ** pointer in case this file-control is not implemented. This file-control
949: ** is intended for diagnostic use only.
1.3 misho 950: **
1.4 misho 951: ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
952: ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
953: ** [VFSes] currently in use. ^(The argument X in
954: ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
955: ** of type "[sqlite3_vfs] **". This opcodes will set *X
956: ** to a pointer to the top-level VFS.)^
957: ** ^When there are multiple VFS shims in the stack, this opcode finds the
958: ** upper-most shim only.
959: **
1.3 misho 960: ** <li>[[SQLITE_FCNTL_PRAGMA]]
1.5 misho 961: ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1.3 misho 962: ** file control is sent to the open [sqlite3_file] object corresponding
963: ** to the database file to which the pragma statement refers. ^The argument
964: ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
965: ** pointers to strings (char**) in which the second element of the array
966: ** is the name of the pragma and the third element is the argument to the
967: ** pragma or NULL if the pragma has no argument. ^The handler for an
968: ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
969: ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
970: ** or the equivalent and that string will become the result of the pragma or
971: ** the error message if the pragma fails. ^If the
1.5 misho 972: ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1.3 misho 973: ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
974: ** file control returns [SQLITE_OK], then the parser assumes that the
975: ** VFS has handled the PRAGMA itself and the parser generates a no-op
1.4 misho 976: ** prepared statement if result string is NULL, or that returns a copy
977: ** of the result string if the string is non-NULL.
978: ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1.3 misho 979: ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
980: ** that the VFS encountered an error while handling the [PRAGMA] and the
981: ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
982: ** file control occurs at the beginning of pragma statement analysis and so
983: ** it is able to override built-in [PRAGMA] statements.
984: **
985: ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1.4 misho 986: ** ^The [SQLITE_FCNTL_BUSYHANDLER]
987: ** file-control may be invoked by SQLite on the database file handle
1.3 misho 988: ** shortly after it is opened in order to provide a custom VFS with access
1.5 misho 989: ** to the connection's busy-handler callback. The argument is of type (void**)
1.3 misho 990: ** - an array of two (void *) values. The first (void *) actually points
1.5 misho 991: ** to a function of type (int (*)(void *)). In order to invoke the connection's
1.3 misho 992: ** busy-handler, this function should be invoked with the second (void *) in
993: ** the array as the only argument. If it returns non-zero, then the operation
994: ** should be retried. If it returns zero, the custom VFS should abandon the
995: ** current operation.
996: **
997: ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1.5 misho 998: ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1.4 misho 999: ** to have SQLite generate a
1.3 misho 1000: ** temporary filename using the same algorithm that is followed to generate
1001: ** temporary filenames for TEMP tables and other internal uses. The
1002: ** argument should be a char** which will be filled with the filename
1003: ** written into memory obtained from [sqlite3_malloc()]. The caller should
1004: ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1005: **
1.4 misho 1006: ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1007: ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1008: ** maximum number of bytes that will be used for memory-mapped I/O.
1009: ** The argument is a pointer to a value of type sqlite3_int64 that
1010: ** is an advisory maximum number of bytes in the file to memory map. The
1011: ** pointer is overwritten with the old value. The limit is not changed if
1.5 misho 1012: ** the value originally pointed to is negative, and so the current limit
1.4 misho 1013: ** can be queried by passing in a pointer to a negative number. This
1014: ** file-control is used internally to implement [PRAGMA mmap_size].
1015: **
1016: ** <li>[[SQLITE_FCNTL_TRACE]]
1017: ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1018: ** to the VFS about what the higher layers of the SQLite stack are doing.
1019: ** This file control is used by some VFS activity tracing [shims].
1020: ** The argument is a zero-terminated string. Higher layers in the
1021: ** SQLite stack may generate instances of this file control if
1022: ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1023: **
1024: ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1025: ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1026: ** pointer to an integer and it writes a boolean into that integer depending
1027: ** on whether or not the file has been renamed, moved, or deleted since it
1028: ** was first opened.
1029: **
1.5 misho 1030: ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1031: ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1032: ** underlying native file handle associated with a file handle. This file
1033: ** control interprets its argument as a pointer to a native file handle and
1034: ** writes the resulting value there.
1035: **
1.4 misho 1036: ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1037: ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1038: ** opcode causes the xFileControl method to swap the file handle with the one
1039: ** pointed to by the pArg argument. This capability is used during testing
1040: ** and only needs to be supported when SQLITE_TEST is defined.
1041: **
1042: ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1043: ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1044: ** be advantageous to block on the next WAL lock if the lock is not immediately
1045: ** available. The WAL subsystem issues this signal during rare
1046: ** circumstances in order to fix a problem with priority inversion.
1047: ** Applications should <em>not</em> use this file-control.
1048: **
1049: ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1050: ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1051: ** VFS should return SQLITE_NOTFOUND for this opcode.
1052: **
1053: ** <li>[[SQLITE_FCNTL_RBU]]
1054: ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1055: ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1.5 misho 1056: ** this opcode.
1057: **
1058: ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1059: ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1060: ** the file descriptor is placed in "batch write mode", which
1061: ** means all subsequent write operations will be deferred and done
1062: ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1063: ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1064: ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1065: ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1066: ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1067: ** no VFS interface calls on the same [sqlite3_file] file descriptor
1068: ** except for calls to the xWrite method and the xFileControl method
1069: ** with [SQLITE_FCNTL_SIZE_HINT].
1070: **
1071: ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1072: ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1073: ** operations since the previous successful call to
1074: ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1075: ** This file control returns [SQLITE_OK] if and only if the writes were
1076: ** all performed successfully and have been committed to persistent storage.
1077: ** ^Regardless of whether or not it is successful, this file control takes
1078: ** the file descriptor out of batch write mode so that all subsequent
1079: ** write operations are independent.
1080: ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1081: ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1082: **
1083: ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1084: ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1085: ** operations since the previous successful call to
1086: ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1087: ** ^This file control takes the file descriptor out of batch write mode
1088: ** so that all subsequent write operations are independent.
1089: ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1090: ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1091: **
1092: ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1093: ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1094: ** to block for up to M milliseconds before failing when attempting to
1095: ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1096: ** The parameter is a pointer to a 32-bit signed integer that contains
1097: ** the value that M is to be set to. Before returning, the 32-bit signed
1098: ** integer is overwritten with the previous value of M.
1099: **
1100: ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1101: ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1102: ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1103: ** The "data version" for the pager is written into the pointer. The
1104: ** "data version" changes whenever any change occurs to the corresponding
1105: ** database file, either through SQL statements on the same database
1106: ** connection or through transactions committed by separate database
1107: ** connections possibly in other processes. The [sqlite3_total_changes()]
1108: ** interface can be used to find if any database on the connection has changed,
1109: ** but that interface responds to changes on TEMP as well as MAIN and does
1110: ** not provide a mechanism to detect changes to MAIN only. Also, the
1111: ** [sqlite3_total_changes()] interface responds to internal changes only and
1112: ** omits changes made by other database connections. The
1113: ** [PRAGMA data_version] command provides a mechanism to detect changes to
1114: ** a single attached database that occur due to other database connections,
1115: ** but omits changes implemented by the database connection on which it is
1116: ** called. This file control is the only mechanism to detect changes that
1117: ** happen either internally or externally and that are associated with
1118: ** a particular attached database.
1119: **
1120: ** <li>[[SQLITE_FCNTL_CKPT_START]]
1121: ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1122: ** in wal mode before the client starts to copy pages from the wal
1123: ** file to the database file.
1124: **
1125: ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1126: ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1127: ** in wal mode after the client has finished copying pages from the wal
1128: ** file to the database file, but before the *-shm file is updated to
1129: ** record the fact that the pages have been checkpointed.
1.3 misho 1130: ** </ul>
1.2 misho 1131: */
1132: #define SQLITE_FCNTL_LOCKSTATE 1
1.4 misho 1133: #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1134: #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1135: #define SQLITE_FCNTL_LAST_ERRNO 4
1.2 misho 1136: #define SQLITE_FCNTL_SIZE_HINT 5
1137: #define SQLITE_FCNTL_CHUNK_SIZE 6
1138: #define SQLITE_FCNTL_FILE_POINTER 7
1139: #define SQLITE_FCNTL_SYNC_OMITTED 8
1140: #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1141: #define SQLITE_FCNTL_PERSIST_WAL 10
1142: #define SQLITE_FCNTL_OVERWRITE 11
1143: #define SQLITE_FCNTL_VFSNAME 12
1144: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1.3 misho 1145: #define SQLITE_FCNTL_PRAGMA 14
1146: #define SQLITE_FCNTL_BUSYHANDLER 15
1147: #define SQLITE_FCNTL_TEMPFILENAME 16
1.4 misho 1148: #define SQLITE_FCNTL_MMAP_SIZE 18
1149: #define SQLITE_FCNTL_TRACE 19
1150: #define SQLITE_FCNTL_HAS_MOVED 20
1151: #define SQLITE_FCNTL_SYNC 21
1152: #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1153: #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1154: #define SQLITE_FCNTL_WAL_BLOCK 24
1155: #define SQLITE_FCNTL_ZIPVFS 25
1156: #define SQLITE_FCNTL_RBU 26
1157: #define SQLITE_FCNTL_VFS_POINTER 27
1158: #define SQLITE_FCNTL_JOURNAL_POINTER 28
1.5 misho 1159: #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1160: #define SQLITE_FCNTL_PDB 30
1161: #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1162: #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1163: #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1164: #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1165: #define SQLITE_FCNTL_DATA_VERSION 35
1166: #define SQLITE_FCNTL_SIZE_LIMIT 36
1167: #define SQLITE_FCNTL_CKPT_DONE 37
1168: #define SQLITE_FCNTL_RESERVE_BYTES 38
1169: #define SQLITE_FCNTL_CKPT_START 39
1.4 misho 1170:
1171: /* deprecated names */
1172: #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1173: #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1174: #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1175:
1.2 misho 1176:
1177: /*
1178: ** CAPI3REF: Mutex Handle
1179: **
1180: ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1181: ** abstract type for a mutex object. The SQLite core never looks
1182: ** at the internal representation of an [sqlite3_mutex]. It only
1183: ** deals with pointers to the [sqlite3_mutex] object.
1184: **
1185: ** Mutexes are created using [sqlite3_mutex_alloc()].
1186: */
1187: typedef struct sqlite3_mutex sqlite3_mutex;
1188:
1189: /*
1.4 misho 1190: ** CAPI3REF: Loadable Extension Thunk
1191: **
1192: ** A pointer to the opaque sqlite3_api_routines structure is passed as
1193: ** the third parameter to entry points of [loadable extensions]. This
1194: ** structure must be typedefed in order to work around compiler warnings
1195: ** on some platforms.
1196: */
1197: typedef struct sqlite3_api_routines sqlite3_api_routines;
1198:
1199: /*
1.2 misho 1200: ** CAPI3REF: OS Interface Object
1201: **
1202: ** An instance of the sqlite3_vfs object defines the interface between
1203: ** the SQLite core and the underlying operating system. The "vfs"
1204: ** in the name of the object stands for "virtual file system". See
1205: ** the [VFS | VFS documentation] for further information.
1206: **
1.5 misho 1207: ** The VFS interface is sometimes extended by adding new methods onto
1208: ** the end. Each time such an extension occurs, the iVersion field
1209: ** is incremented. The iVersion value started out as 1 in
1210: ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1211: ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1212: ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1213: ** may be appended to the sqlite3_vfs object and the iVersion value
1214: ** may increase again in future versions of SQLite.
1215: ** Note that due to an oversight, the structure
1216: ** of the sqlite3_vfs object changed in the transition from
1217: ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1218: ** and yet the iVersion field was not increased.
1.2 misho 1219: **
1220: ** The szOsFile field is the size of the subclassed [sqlite3_file]
1221: ** structure used by this VFS. mxPathname is the maximum length of
1222: ** a pathname in this VFS.
1223: **
1224: ** Registered sqlite3_vfs objects are kept on a linked list formed by
1225: ** the pNext pointer. The [sqlite3_vfs_register()]
1226: ** and [sqlite3_vfs_unregister()] interfaces manage this list
1227: ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1228: ** searches the list. Neither the application code nor the VFS
1229: ** implementation should use the pNext pointer.
1230: **
1231: ** The pNext field is the only field in the sqlite3_vfs
1232: ** structure that SQLite will ever modify. SQLite will only access
1233: ** or modify this field while holding a particular static mutex.
1234: ** The application should never modify anything within the sqlite3_vfs
1235: ** object once the object has been registered.
1236: **
1237: ** The zName field holds the name of the VFS module. The name must
1238: ** be unique across all VFS modules.
1239: **
1240: ** [[sqlite3_vfs.xOpen]]
1241: ** ^SQLite guarantees that the zFilename parameter to xOpen
1242: ** is either a NULL pointer or string obtained
1243: ** from xFullPathname() with an optional suffix added.
1244: ** ^If a suffix is added to the zFilename parameter, it will
1245: ** consist of a single "-" character followed by no more than
1246: ** 11 alphanumeric and/or "-" characters.
1247: ** ^SQLite further guarantees that
1248: ** the string will be valid and unchanged until xClose() is
1249: ** called. Because of the previous sentence,
1250: ** the [sqlite3_file] can safely store a pointer to the
1251: ** filename if it needs to remember the filename for some reason.
1252: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1.5 misho 1253: ** must invent its own temporary name for the file. ^Whenever the
1.2 misho 1254: ** xFilename parameter is NULL it will also be the case that the
1255: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1256: **
1257: ** The flags argument to xOpen() includes all bits set in
1258: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1259: ** or [sqlite3_open16()] is used, then flags includes at least
1.5 misho 1260: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1.2 misho 1261: ** If xOpen() opens a file read-only then it sets *pOutFlags to
1262: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1263: **
1264: ** ^(SQLite will also add one of the following flags to the xOpen()
1265: ** call, depending on the object being opened:
1266: **
1267: ** <ul>
1268: ** <li> [SQLITE_OPEN_MAIN_DB]
1269: ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1270: ** <li> [SQLITE_OPEN_TEMP_DB]
1271: ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1272: ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1273: ** <li> [SQLITE_OPEN_SUBJOURNAL]
1.5 misho 1274: ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1.2 misho 1275: ** <li> [SQLITE_OPEN_WAL]
1276: ** </ul>)^
1277: **
1278: ** The file I/O implementation can use the object type flags to
1279: ** change the way it deals with files. For example, an application
1280: ** that does not care about crash recovery or rollback might make
1281: ** the open of a journal file a no-op. Writes to this journal would
1282: ** also be no-ops, and any attempt to read the journal would return
1283: ** SQLITE_IOERR. Or the implementation might recognize that a database
1284: ** file will be doing page-aligned sector reads and writes in a random
1285: ** order and set up its I/O subsystem accordingly.
1286: **
1287: ** SQLite might also add one of the following flags to the xOpen method:
1288: **
1289: ** <ul>
1290: ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1291: ** <li> [SQLITE_OPEN_EXCLUSIVE]
1292: ** </ul>
1293: **
1294: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1295: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1296: ** will be set for TEMP databases and their journals, transient
1297: ** databases, and subjournals.
1298: **
1299: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1300: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1301: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1.5 misho 1302: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1.2 misho 1303: ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1304: ** be created, and that it is an error if it already exists.
1.5 misho 1305: ** It is <i>not</i> used to indicate the file should be opened
1.2 misho 1306: ** for exclusive access.
1307: **
1308: ** ^At least szOsFile bytes of memory are allocated by SQLite
1.5 misho 1309: ** to hold the [sqlite3_file] structure passed as the third
1.2 misho 1310: ** argument to xOpen. The xOpen method does not have to
1311: ** allocate the structure; it should just fill it in. Note that
1312: ** the xOpen method must set the sqlite3_file.pMethods to either
1313: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1314: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1315: ** element will be valid after xOpen returns regardless of the success
1316: ** or failure of the xOpen call.
1317: **
1318: ** [[sqlite3_vfs.xAccess]]
1319: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1320: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1321: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1.5 misho 1322: ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1323: ** flag is never actually used and is not implemented in the built-in
1324: ** VFSes of SQLite. The file is named by the second argument and can be a
1325: ** directory. The xAccess method returns [SQLITE_OK] on success or some
1326: ** non-zero error code if there is an I/O error or if the name of
1327: ** the file given in the second argument is illegal. If SQLITE_OK
1328: ** is returned, then non-zero or zero is written into *pResOut to indicate
1329: ** whether or not the file is accessible.
1.2 misho 1330: **
1331: ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1332: ** output buffer xFullPathname. The exact size of the output buffer
1333: ** is also passed as a parameter to both methods. If the output buffer
1334: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1335: ** handled as a fatal error by SQLite, vfs implementations should endeavor
1336: ** to prevent this by setting mxPathname to a sufficiently large value.
1337: **
1338: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1339: ** interfaces are not strictly a part of the filesystem, but they are
1340: ** included in the VFS structure for completeness.
1341: ** The xRandomness() function attempts to return nBytes bytes
1342: ** of good-quality randomness into zOut. The return value is
1343: ** the actual number of bytes of randomness obtained.
1344: ** The xSleep() method causes the calling thread to sleep for at
1345: ** least the number of microseconds given. ^The xCurrentTime()
1346: ** method returns a Julian Day Number for the current date and time as
1347: ** a floating point value.
1348: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1.5 misho 1349: ** Day Number multiplied by 86400000 (the number of milliseconds in
1350: ** a 24-hour day).
1.2 misho 1351: ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1.5 misho 1352: ** date and time if that method is available (if iVersion is 2 or
1.2 misho 1353: ** greater and the function pointer is not NULL) and will fall back
1354: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1355: **
1356: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1357: ** are not used by the SQLite core. These optional interfaces are provided
1.5 misho 1358: ** by some VFSes to facilitate testing of the VFS code. By overriding
1.2 misho 1359: ** system calls with functions under its control, a test program can
1360: ** simulate faults and error conditions that would otherwise be difficult
1361: ** or impossible to induce. The set of system calls that can be overridden
1362: ** varies from one VFS to another, and from one version of the same VFS to the
1363: ** next. Applications that use these interfaces must be prepared for any
1364: ** or all of these interfaces to be NULL or for their behavior to change
1365: ** from one release to the next. Applications must not attempt to access
1366: ** any of these methods if the iVersion of the VFS is less than 3.
1367: */
1368: typedef struct sqlite3_vfs sqlite3_vfs;
1369: typedef void (*sqlite3_syscall_ptr)(void);
1370: struct sqlite3_vfs {
1371: int iVersion; /* Structure version number (currently 3) */
1372: int szOsFile; /* Size of subclassed sqlite3_file */
1373: int mxPathname; /* Maximum file pathname length */
1374: sqlite3_vfs *pNext; /* Next registered VFS */
1375: const char *zName; /* Name of this virtual file system */
1376: void *pAppData; /* Pointer to application-specific data */
1377: int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1378: int flags, int *pOutFlags);
1379: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1380: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1381: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1382: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1383: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1384: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1385: void (*xDlClose)(sqlite3_vfs*, void*);
1386: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1387: int (*xSleep)(sqlite3_vfs*, int microseconds);
1388: int (*xCurrentTime)(sqlite3_vfs*, double*);
1389: int (*xGetLastError)(sqlite3_vfs*, int, char *);
1390: /*
1391: ** The methods above are in version 1 of the sqlite_vfs object
1392: ** definition. Those that follow are added in version 2 or later
1393: */
1394: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1395: /*
1396: ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1397: ** Those below are for version 3 and greater.
1398: */
1399: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1400: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1401: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1402: /*
1403: ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1.4 misho 1404: ** New fields may be appended in future versions. The iVersion
1.5 misho 1405: ** value will increment whenever this happens.
1.2 misho 1406: */
1407: };
1408:
1409: /*
1410: ** CAPI3REF: Flags for the xAccess VFS method
1411: **
1412: ** These integer constants can be used as the third parameter to
1413: ** the xAccess method of an [sqlite3_vfs] object. They determine
1414: ** what kind of permissions the xAccess method is looking for.
1415: ** With SQLITE_ACCESS_EXISTS, the xAccess method
1416: ** simply checks whether the file exists.
1417: ** With SQLITE_ACCESS_READWRITE, the xAccess method
1418: ** checks whether the named directory is both readable and writable
1419: ** (in other words, if files can be added, removed, and renamed within
1420: ** the directory).
1421: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1422: ** [temp_store_directory pragma], though this could change in a future
1423: ** release of SQLite.
1424: ** With SQLITE_ACCESS_READ, the xAccess method
1425: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1426: ** currently unused, though it might be used in a future release of
1427: ** SQLite.
1428: */
1429: #define SQLITE_ACCESS_EXISTS 0
1430: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1431: #define SQLITE_ACCESS_READ 2 /* Unused */
1432:
1433: /*
1434: ** CAPI3REF: Flags for the xShmLock VFS method
1435: **
1436: ** These integer constants define the various locking operations
1437: ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1438: ** following are the only legal combinations of flags to the
1439: ** xShmLock method:
1440: **
1441: ** <ul>
1442: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1443: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1444: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1445: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1446: ** </ul>
1447: **
1448: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1.5 misho 1449: ** was given on the corresponding lock.
1.2 misho 1450: **
1451: ** The xShmLock method can transition between unlocked and SHARED or
1452: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1453: ** and EXCLUSIVE.
1454: */
1455: #define SQLITE_SHM_UNLOCK 1
1456: #define SQLITE_SHM_LOCK 2
1457: #define SQLITE_SHM_SHARED 4
1458: #define SQLITE_SHM_EXCLUSIVE 8
1459:
1460: /*
1461: ** CAPI3REF: Maximum xShmLock index
1462: **
1463: ** The xShmLock method on [sqlite3_io_methods] may use values
1464: ** between 0 and this upper bound as its "offset" argument.
1465: ** The SQLite core will never attempt to acquire or release a
1466: ** lock outside of this range
1467: */
1468: #define SQLITE_SHM_NLOCK 8
1469:
1470:
1471: /*
1472: ** CAPI3REF: Initialize The SQLite Library
1473: **
1474: ** ^The sqlite3_initialize() routine initializes the
1475: ** SQLite library. ^The sqlite3_shutdown() routine
1476: ** deallocates any resources that were allocated by sqlite3_initialize().
1477: ** These routines are designed to aid in process initialization and
1478: ** shutdown on embedded systems. Workstation applications using
1479: ** SQLite normally do not need to invoke either of these routines.
1480: **
1481: ** A call to sqlite3_initialize() is an "effective" call if it is
1482: ** the first time sqlite3_initialize() is invoked during the lifetime of
1483: ** the process, or if it is the first time sqlite3_initialize() is invoked
1484: ** following a call to sqlite3_shutdown(). ^(Only an effective call
1485: ** of sqlite3_initialize() does any initialization. All other calls
1486: ** are harmless no-ops.)^
1487: **
1488: ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1489: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1490: ** an effective call to sqlite3_shutdown() does any deinitialization.
1491: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1492: **
1493: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1494: ** is not. The sqlite3_shutdown() interface must only be called from a
1495: ** single thread. All open [database connections] must be closed and all
1496: ** other SQLite resources must be deallocated prior to invoking
1497: ** sqlite3_shutdown().
1498: **
1499: ** Among other things, ^sqlite3_initialize() will invoke
1500: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1501: ** will invoke sqlite3_os_end().
1502: **
1503: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1504: ** ^If for some reason, sqlite3_initialize() is unable to initialize
1505: ** the library (perhaps it is unable to allocate a needed resource such
1506: ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1507: **
1508: ** ^The sqlite3_initialize() routine is called internally by many other
1509: ** SQLite interfaces so that an application usually does not need to
1510: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1511: ** calls sqlite3_initialize() so the SQLite library will be automatically
1512: ** initialized when [sqlite3_open()] is called if it has not be initialized
1513: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1514: ** compile-time option, then the automatic calls to sqlite3_initialize()
1515: ** are omitted and the application must call sqlite3_initialize() directly
1516: ** prior to using any other SQLite interface. For maximum portability,
1517: ** it is recommended that applications always invoke sqlite3_initialize()
1518: ** directly prior to using any other SQLite interface. Future releases
1519: ** of SQLite may require this. In other words, the behavior exhibited
1520: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1521: ** default behavior in some future release of SQLite.
1522: **
1523: ** The sqlite3_os_init() routine does operating-system specific
1524: ** initialization of the SQLite library. The sqlite3_os_end()
1525: ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1526: ** performed by these routines include allocation or deallocation
1527: ** of static resources, initialization of global variables,
1528: ** setting up a default [sqlite3_vfs] module, or setting up
1529: ** a default configuration using [sqlite3_config()].
1530: **
1531: ** The application should never invoke either sqlite3_os_init()
1532: ** or sqlite3_os_end() directly. The application should only invoke
1533: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1534: ** interface is called automatically by sqlite3_initialize() and
1535: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1536: ** implementations for sqlite3_os_init() and sqlite3_os_end()
1537: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1538: ** When [custom builds | built for other platforms]
1539: ** (using the [SQLITE_OS_OTHER=1] compile-time
1540: ** option) the application must supply a suitable implementation for
1541: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1542: ** implementation of sqlite3_os_init() or sqlite3_os_end()
1543: ** must return [SQLITE_OK] on success and some other [error code] upon
1544: ** failure.
1545: */
1546: SQLITE_API int sqlite3_initialize(void);
1547: SQLITE_API int sqlite3_shutdown(void);
1548: SQLITE_API int sqlite3_os_init(void);
1549: SQLITE_API int sqlite3_os_end(void);
1550:
1551: /*
1552: ** CAPI3REF: Configuring The SQLite Library
1553: **
1554: ** The sqlite3_config() interface is used to make global configuration
1555: ** changes to SQLite in order to tune SQLite to the specific needs of
1556: ** the application. The default configuration is recommended for most
1557: ** applications and so this routine is usually not necessary. It is
1558: ** provided to support rare applications with unusual needs.
1559: **
1.4 misho 1560: ** <b>The sqlite3_config() interface is not threadsafe. The application
1561: ** must ensure that no other SQLite interfaces are invoked by other
1562: ** threads while sqlite3_config() is running.</b>
1563: **
1564: ** The sqlite3_config() interface
1.2 misho 1565: ** may only be invoked prior to library initialization using
1566: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1567: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1568: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1569: ** Note, however, that ^sqlite3_config() can be called as part of the
1570: ** implementation of an application-defined [sqlite3_os_init()].
1571: **
1572: ** The first argument to sqlite3_config() is an integer
1573: ** [configuration option] that determines
1574: ** what property of SQLite is to be configured. Subsequent arguments
1575: ** vary depending on the [configuration option]
1576: ** in the first argument.
1577: **
1578: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1579: ** ^If the option is unknown or SQLite is unable to set the option
1580: ** then this routine returns a non-zero [error code].
1581: */
1582: SQLITE_API int sqlite3_config(int, ...);
1583:
1584: /*
1585: ** CAPI3REF: Configure database connections
1.4 misho 1586: ** METHOD: sqlite3
1.2 misho 1587: **
1588: ** The sqlite3_db_config() interface is used to make configuration
1589: ** changes to a [database connection]. The interface is similar to
1590: ** [sqlite3_config()] except that the changes apply to a single
1591: ** [database connection] (specified in the first argument).
1592: **
1593: ** The second argument to sqlite3_db_config(D,V,...) is the
1.5 misho 1594: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1.2 misho 1595: ** that indicates what aspect of the [database connection] is being configured.
1596: ** Subsequent arguments vary depending on the configuration verb.
1597: **
1598: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1599: ** the call is considered successful.
1600: */
1601: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1602:
1603: /*
1604: ** CAPI3REF: Memory Allocation Routines
1605: **
1606: ** An instance of this object defines the interface between SQLite
1607: ** and low-level memory allocation routines.
1608: **
1609: ** This object is used in only one place in the SQLite interface.
1610: ** A pointer to an instance of this object is the argument to
1611: ** [sqlite3_config()] when the configuration option is
1.5 misho 1612: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1.2 misho 1613: ** By creating an instance of this object
1614: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1615: ** during configuration, an application can specify an alternative
1616: ** memory allocation subsystem for SQLite to use for all of its
1617: ** dynamic memory needs.
1618: **
1619: ** Note that SQLite comes with several [built-in memory allocators]
1620: ** that are perfectly adequate for the overwhelming majority of applications
1621: ** and that this object is only useful to a tiny minority of applications
1622: ** with specialized memory allocation requirements. This object is
1623: ** also used during testing of SQLite in order to specify an alternative
1624: ** memory allocator that simulates memory out-of-memory conditions in
1625: ** order to verify that SQLite recovers gracefully from such
1626: ** conditions.
1627: **
1628: ** The xMalloc, xRealloc, and xFree methods must work like the
1629: ** malloc(), realloc() and free() functions from the standard C library.
1630: ** ^SQLite guarantees that the second argument to
1631: ** xRealloc is always a value returned by a prior call to xRoundup.
1632: **
1633: ** xSize should return the allocated size of a memory allocation
1634: ** previously obtained from xMalloc or xRealloc. The allocated size
1635: ** is always at least as big as the requested size but may be larger.
1636: **
1637: ** The xRoundup method returns what would be the allocated size of
1638: ** a memory allocation given a particular requested size. Most memory
1639: ** allocators round up memory allocations at least to the next multiple
1640: ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1641: ** Every memory allocation request coming in through [sqlite3_malloc()]
1.5 misho 1642: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1.2 misho 1643: ** that causes the corresponding memory allocation to fail.
1644: **
1.4 misho 1645: ** The xInit method initializes the memory allocator. For example,
1.5 misho 1646: ** it might allocate any required mutexes or initialize internal data
1.2 misho 1647: ** structures. The xShutdown method is invoked (indirectly) by
1648: ** [sqlite3_shutdown()] and should deallocate any resources acquired
1649: ** by xInit. The pAppData pointer is used as the only parameter to
1650: ** xInit and xShutdown.
1651: **
1.5 misho 1652: ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1.2 misho 1653: ** the xInit method, so the xInit method need not be threadsafe. The
1654: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1655: ** not need to be threadsafe either. For all other methods, SQLite
1656: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1657: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1658: ** it is by default) and so the methods are automatically serialized.
1659: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1660: ** methods must be threadsafe or else make their own arrangements for
1661: ** serialization.
1662: **
1663: ** SQLite will never invoke xInit() more than once without an intervening
1664: ** call to xShutdown().
1665: */
1666: typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1667: struct sqlite3_mem_methods {
1668: void *(*xMalloc)(int); /* Memory allocation function */
1669: void (*xFree)(void*); /* Free a prior allocation */
1670: void *(*xRealloc)(void*,int); /* Resize an allocation */
1671: int (*xSize)(void*); /* Return the size of an allocation */
1672: int (*xRoundup)(int); /* Round up request size to allocation size */
1673: int (*xInit)(void*); /* Initialize the memory allocator */
1674: void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1675: void *pAppData; /* Argument to xInit() and xShutdown() */
1676: };
1677:
1678: /*
1679: ** CAPI3REF: Configuration Options
1680: ** KEYWORDS: {configuration option}
1681: **
1682: ** These constants are the available integer configuration options that
1683: ** can be passed as the first argument to the [sqlite3_config()] interface.
1684: **
1685: ** New configuration options may be added in future releases of SQLite.
1686: ** Existing configuration options might be discontinued. Applications
1687: ** should check the return code from [sqlite3_config()] to make sure that
1688: ** the call worked. The [sqlite3_config()] interface will return a
1689: ** non-zero [error code] if a discontinued or unsupported configuration option
1690: ** is invoked.
1691: **
1692: ** <dl>
1693: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1694: ** <dd>There are no arguments to this option. ^This option sets the
1695: ** [threading mode] to Single-thread. In other words, it disables
1696: ** all mutexing and puts SQLite into a mode where it can only be used
1697: ** by a single thread. ^If SQLite is compiled with
1698: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1699: ** it is not possible to change the [threading mode] from its default
1.5 misho 1700: ** value of Single-thread and so [sqlite3_config()] will return
1.2 misho 1701: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1702: ** configuration option.</dd>
1703: **
1704: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1705: ** <dd>There are no arguments to this option. ^This option sets the
1706: ** [threading mode] to Multi-thread. In other words, it disables
1707: ** mutexing on [database connection] and [prepared statement] objects.
1708: ** The application is responsible for serializing access to
1709: ** [database connections] and [prepared statements]. But other mutexes
1710: ** are enabled so that SQLite will be safe to use in a multi-threaded
1711: ** environment as long as no two threads attempt to use the same
1712: ** [database connection] at the same time. ^If SQLite is compiled with
1713: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1714: ** it is not possible to set the Multi-thread [threading mode] and
1715: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1716: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1717: **
1718: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1719: ** <dd>There are no arguments to this option. ^This option sets the
1720: ** [threading mode] to Serialized. In other words, this option enables
1721: ** all mutexes including the recursive
1722: ** mutexes on [database connection] and [prepared statement] objects.
1723: ** In this mode (which is the default when SQLite is compiled with
1724: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1725: ** to [database connections] and [prepared statements] so that the
1726: ** application is free to use the same [database connection] or the
1727: ** same [prepared statement] in different threads at the same time.
1728: ** ^If SQLite is compiled with
1729: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1730: ** it is not possible to set the Serialized [threading mode] and
1731: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1732: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1733: **
1734: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1.5 misho 1735: ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1.4 misho 1736: ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1737: ** The argument specifies
1.2 misho 1738: ** alternative low-level memory allocation routines to be used in place of
1739: ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1740: ** its own private copy of the content of the [sqlite3_mem_methods] structure
1741: ** before the [sqlite3_config()] call returns.</dd>
1742: **
1743: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1.4 misho 1744: ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1745: ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1746: ** The [sqlite3_mem_methods]
1.2 misho 1747: ** structure is filled with the currently defined memory allocation routines.)^
1748: ** This option can be used to overload the default memory allocation
1749: ** routines with a wrapper that simulations memory allocation failure or
1750: ** tracks memory usage, for example. </dd>
1751: **
1.5 misho 1752: ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1753: ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1754: ** type int, interpreted as a boolean, which if true provides a hint to
1755: ** SQLite that it should avoid large memory allocations if possible.
1756: ** SQLite will run faster if it is free to make large memory allocations,
1757: ** but some application might prefer to run slower in exchange for
1758: ** guarantees about memory fragmentation that are possible if large
1759: ** allocations are avoided. This hint is normally off.
1760: ** </dd>
1761: **
1.2 misho 1762: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1.4 misho 1763: ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1764: ** interpreted as a boolean, which enables or disables the collection of
1765: ** memory allocation statistics. ^(When memory allocation statistics are
1766: ** disabled, the following SQLite interfaces become non-operational:
1.2 misho 1767: ** <ul>
1.5 misho 1768: ** <li> [sqlite3_hard_heap_limit64()]
1.2 misho 1769: ** <li> [sqlite3_memory_used()]
1770: ** <li> [sqlite3_memory_highwater()]
1771: ** <li> [sqlite3_soft_heap_limit64()]
1.4 misho 1772: ** <li> [sqlite3_status64()]
1.2 misho 1773: ** </ul>)^
1774: ** ^Memory allocation statistics are enabled by default unless SQLite is
1775: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1776: ** allocation statistics are disabled by default.
1777: ** </dd>
1778: **
1779: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1.5 misho 1780: ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1.4 misho 1781: ** </dd>
1.2 misho 1782: **
1783: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1.4 misho 1784: ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1785: ** that SQLite can use for the database page cache with the default page
1.5 misho 1786: ** cache implementation.
1787: ** This configuration option is a no-op if an application-defined page
1.4 misho 1788: ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1789: ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1790: ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1791: ** and the number of cache lines (N).
1.2 misho 1792: ** The sz argument should be the size of the largest database page
1.4 misho 1793: ** (a power of two between 512 and 65536) plus some extra bytes for each
1794: ** page header. ^The number of extra bytes needed by the page header
1795: ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1796: ** ^It is harmless, apart from the wasted memory,
1797: ** for the sz parameter to be larger than necessary. The pMem
1798: ** argument must be either a NULL pointer or a pointer to an 8-byte
1799: ** aligned block of memory of at least sz*N bytes, otherwise
1800: ** subsequent behavior is undefined.
1801: ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1802: ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1803: ** a page cache line is larger than sz bytes or if all of the pMem buffer
1804: ** is exhausted.
1805: ** ^If pMem is NULL and N is non-zero, then each database connection
1806: ** does an initial bulk allocation for page cache memory
1807: ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1808: ** of -1024*N bytes if N is negative, . ^If additional
1809: ** page cache memory is needed beyond what is provided by the initial
1810: ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1811: ** additional cache line. </dd>
1.2 misho 1812: **
1813: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1.5 misho 1814: ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1.4 misho 1815: ** that SQLite will use for all of its dynamic memory allocation needs
1.5 misho 1816: ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1.4 misho 1817: ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1818: ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1819: ** [SQLITE_ERROR] if invoked otherwise.
1820: ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1821: ** An 8-byte aligned pointer to the memory,
1.2 misho 1822: ** the number of bytes in the memory buffer, and the minimum allocation size.
1823: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1824: ** to using its default memory allocator (the system malloc() implementation),
1825: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1.4 misho 1826: ** memory pointer is not NULL then the alternative memory
1.2 misho 1827: ** allocator is engaged to handle all of SQLites memory allocation needs.
1828: ** The first pointer (the memory pointer) must be aligned to an 8-byte
1829: ** boundary or subsequent behavior of SQLite will be undefined.
1830: ** The minimum allocation size is capped at 2**12. Reasonable values
1831: ** for the minimum allocation size are 2**5 through 2**8.</dd>
1832: **
1833: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1.4 misho 1834: ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1835: ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1836: ** The argument specifies alternative low-level mutex routines to be used
1837: ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1838: ** the content of the [sqlite3_mutex_methods] structure before the call to
1.2 misho 1839: ** [sqlite3_config()] returns. ^If SQLite is compiled with
1840: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1841: ** the entire mutexing subsystem is omitted from the build and hence calls to
1842: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1843: ** return [SQLITE_ERROR].</dd>
1844: **
1845: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1.4 misho 1846: ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1847: ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1.2 misho 1848: ** [sqlite3_mutex_methods]
1849: ** structure is filled with the currently defined mutex routines.)^
1850: ** This option can be used to overload the default mutex allocation
1851: ** routines with a wrapper used to track mutex usage for performance
1852: ** profiling or testing, for example. ^If SQLite is compiled with
1853: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1854: ** the entire mutexing subsystem is omitted from the build and hence calls to
1855: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1856: ** return [SQLITE_ERROR].</dd>
1857: **
1858: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1.4 misho 1859: ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1860: ** the default size of lookaside memory on each [database connection].
1861: ** The first argument is the
1.2 misho 1862: ** size of each lookaside buffer slot and the second is the number of
1.4 misho 1863: ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1864: ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1865: ** option to [sqlite3_db_config()] can be used to change the lookaside
1.2 misho 1866: ** configuration on individual connections.)^ </dd>
1867: **
1868: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1.5 misho 1869: ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1.4 misho 1870: ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1871: ** the interface to a custom page cache implementation.)^
1872: ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1.2 misho 1873: **
1874: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1.4 misho 1875: ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1876: ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1877: ** the current page cache implementation into that object.)^ </dd>
1.2 misho 1878: **
1879: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1.4 misho 1880: ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1881: ** global [error log].
1882: ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1.5 misho 1883: ** function with a call signature of void(*)(void*,int,const char*),
1.2 misho 1884: ** and a pointer to void. ^If the function pointer is not NULL, it is
1885: ** invoked by [sqlite3_log()] to process each logging event. ^If the
1886: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1887: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1888: ** passed through as the first parameter to the application-defined logger
1889: ** function whenever that function is invoked. ^The second parameter to
1890: ** the logger function is a copy of the first parameter to the corresponding
1891: ** [sqlite3_log()] call and is intended to be a [result code] or an
1892: ** [extended result code]. ^The third parameter passed to the logger is
1893: ** log message after formatting via [sqlite3_snprintf()].
1894: ** The SQLite logging interface is not reentrant; the logger function
1895: ** supplied by the application must not invoke any SQLite interface.
1896: ** In a multi-threaded application, the application-defined logger
1897: ** function must be threadsafe. </dd>
1898: **
1899: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1.4 misho 1900: ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1901: ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1902: ** then URI handling is globally disabled.)^ ^If URI handling is globally
1903: ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1904: ** [sqlite3_open16()] or
1.2 misho 1905: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1906: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1.4 misho 1907: ** connection is opened. ^If it is globally disabled, filenames are
1.2 misho 1908: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1.4 misho 1909: ** database connection is opened. ^(By default, URI handling is globally
1.2 misho 1910: ** disabled. The default value may be changed by compiling with the
1.4 misho 1911: ** [SQLITE_USE_URI] symbol defined.)^
1.2 misho 1912: **
1.3 misho 1913: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1.4 misho 1914: ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1915: ** argument which is interpreted as a boolean in order to enable or disable
1916: ** the use of covering indices for full table scans in the query optimizer.
1917: ** ^The default setting is determined
1.3 misho 1918: ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1919: ** if that compile-time option is omitted.
1920: ** The ability to disable the use of covering indices for full table scans
1921: ** is because some incorrectly coded legacy applications might malfunction
1.4 misho 1922: ** when the optimization is enabled. Providing the ability to
1.3 misho 1923: ** disable the optimization allows the older, buggy application code to work
1924: ** without change even with newer versions of SQLite.
1925: **
1.2 misho 1926: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1.3 misho 1927: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1.2 misho 1928: ** <dd> These options are obsolete and should not be used by new code.
1929: ** They are retained for backwards compatibility but are now no-ops.
1.4 misho 1930: ** </dd>
1.3 misho 1931: **
1932: ** [[SQLITE_CONFIG_SQLLOG]]
1933: ** <dt>SQLITE_CONFIG_SQLLOG
1934: ** <dd>This option is only available if sqlite is compiled with the
1.4 misho 1935: ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1.3 misho 1936: ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1937: ** The second should be of type (void*). The callback is invoked by the library
1938: ** in three separate circumstances, identified by the value passed as the
1939: ** fourth parameter. If the fourth parameter is 0, then the database connection
1940: ** passed as the second argument has just been opened. The third argument
1941: ** points to a buffer containing the name of the main database file. If the
1942: ** fourth parameter is 1, then the SQL statement that the third parameter
1943: ** points to has just been executed. Or, if the fourth parameter is 2, then
1944: ** the connection being passed as the second parameter is being closed. The
1.4 misho 1945: ** third parameter is passed NULL In this case. An example of using this
1946: ** configuration option can be seen in the "test_sqllog.c" source file in
1947: ** the canonical SQLite source tree.</dd>
1948: **
1949: ** [[SQLITE_CONFIG_MMAP_SIZE]]
1950: ** <dt>SQLITE_CONFIG_MMAP_SIZE
1951: ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1952: ** that are the default mmap size limit (the default setting for
1953: ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1954: ** ^The default setting can be overridden by each database connection using
1955: ** either the [PRAGMA mmap_size] command, or by using the
1956: ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1957: ** will be silently truncated if necessary so that it does not exceed the
1958: ** compile-time maximum mmap size set by the
1959: ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1960: ** ^If either argument to this option is negative, then that argument is
1961: ** changed to its compile-time default.
1962: **
1963: ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1964: ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1965: ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1966: ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1967: ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1968: ** that specifies the maximum size of the created heap.
1969: **
1970: ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1971: ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1972: ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1973: ** is a pointer to an integer and writes into that integer the number of extra
1974: ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1975: ** The amount of extra space required can change depending on the compiler,
1976: ** target platform, and SQLite version.
1977: **
1978: ** [[SQLITE_CONFIG_PMASZ]]
1979: ** <dt>SQLITE_CONFIG_PMASZ
1980: ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1981: ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1982: ** sorter to that integer. The default minimum PMA Size is set by the
1983: ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1984: ** to help with sort operations when multithreaded sorting
1985: ** is enabled (using the [PRAGMA threads] command) and the amount of content
1986: ** to be sorted exceeds the page size times the minimum of the
1987: ** [PRAGMA cache_size] setting and this value.
1988: **
1989: ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1990: ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1991: ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1.5 misho 1992: ** becomes the [statement journal] spill-to-disk threshold.
1.4 misho 1993: ** [Statement journals] are held in memory until their size (in bytes)
1994: ** exceeds this threshold, at which point they are written to disk.
1995: ** Or if the threshold is -1, statement journals are always held
1996: ** exclusively in memory.
1997: ** Since many statement journals never become large, setting the spill
1998: ** threshold to a value such as 64KiB can greatly reduce the amount of
1999: ** I/O required to support statement rollback.
2000: ** The default value for this setting is controlled by the
2001: ** [SQLITE_STMTJRNL_SPILL] compile-time option.
1.5 misho 2002: **
2003: ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2004: ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2005: ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2006: ** of type (int) - the new value of the sorter-reference size threshold.
2007: ** Usually, when SQLite uses an external sort to order records according
2008: ** to an ORDER BY clause, all fields required by the caller are present in the
2009: ** sorted records. However, if SQLite determines based on the declared type
2010: ** of a table column that its values are likely to be very large - larger
2011: ** than the configured sorter-reference size threshold - then a reference
2012: ** is stored in each sorted record and the required column values loaded
2013: ** from the database as records are returned in sorted order. The default
2014: ** value for this option is to never use this optimization. Specifying a
2015: ** negative value for this option restores the default behaviour.
2016: ** This option is only available if SQLite is compiled with the
2017: ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2018: **
2019: ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2020: ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2021: ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2022: ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2023: ** database created using [sqlite3_deserialize()]. This default maximum
2024: ** size can be adjusted up or down for individual databases using the
2025: ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2026: ** configuration setting is never used, then the default maximum is determined
2027: ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2028: ** compile-time option is not set, then the default maximum is 1073741824.
1.3 misho 2029: ** </dl>
1.2 misho 2030: */
2031: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2032: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2033: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2034: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2035: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1.5 misho 2036: #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
1.2 misho 2037: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2038: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2039: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2040: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2041: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1.5 misho 2042: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1.2 misho 2043: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2044: #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2045: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2046: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2047: #define SQLITE_CONFIG_URI 17 /* int */
2048: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2049: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1.3 misho 2050: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2051: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1.4 misho 2052: #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2053: #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2054: #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2055: #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2056: #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
1.5 misho 2057: #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2058: #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2059: #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
1.2 misho 2060:
2061: /*
2062: ** CAPI3REF: Database Connection Configuration Options
2063: **
2064: ** These constants are the available integer configuration options that
2065: ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2066: **
2067: ** New configuration options may be added in future releases of SQLite.
2068: ** Existing configuration options might be discontinued. Applications
2069: ** should check the return code from [sqlite3_db_config()] to make sure that
2070: ** the call worked. ^The [sqlite3_db_config()] interface will return a
2071: ** non-zero [error code] if a discontinued or unsupported configuration option
2072: ** is invoked.
2073: **
2074: ** <dl>
1.5 misho 2075: ** [[SQLITE_DBCONFIG_LOOKASIDE]]
1.2 misho 2076: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1.5 misho 2077: ** <dd> ^This option takes three additional arguments that determine the
1.2 misho 2078: ** [lookaside memory allocator] configuration for the [database connection].
2079: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2080: ** pointer to a memory buffer to use for lookaside memory.
2081: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2082: ** may be NULL in which case SQLite will allocate the
2083: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2084: ** size of each lookaside buffer slot. ^The third argument is the number of
2085: ** slots. The size of the buffer in the first argument must be greater than
2086: ** or equal to the product of the second and third arguments. The buffer
2087: ** must be aligned to an 8-byte boundary. ^If the second argument to
2088: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2089: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2090: ** configuration for a database connection can only be changed when that
2091: ** connection is not currently using lookaside memory, or in other words
2092: ** when the "current value" returned by
2093: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2094: ** Any attempt to change the lookaside memory configuration when lookaside
1.5 misho 2095: ** memory is in use leaves the configuration unchanged and returns
1.2 misho 2096: ** [SQLITE_BUSY].)^</dd>
2097: **
1.5 misho 2098: ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
1.2 misho 2099: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2100: ** <dd> ^This option is used to enable or disable the enforcement of
2101: ** [foreign key constraints]. There should be two additional arguments.
2102: ** The first argument is an integer which is 0 to disable FK enforcement,
2103: ** positive to enable FK enforcement or negative to leave FK enforcement
2104: ** unchanged. The second parameter is a pointer to an integer into which
2105: ** is written 0 or 1 to indicate whether FK enforcement is off or on
2106: ** following this call. The second parameter may be a NULL pointer, in
2107: ** which case the FK enforcement setting is not reported back. </dd>
2108: **
1.5 misho 2109: ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
1.2 misho 2110: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2111: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2112: ** There should be two additional arguments.
2113: ** The first argument is an integer which is 0 to disable triggers,
2114: ** positive to enable triggers or negative to leave the setting unchanged.
2115: ** The second parameter is a pointer to an integer into which
2116: ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2117: ** following this call. The second parameter may be a NULL pointer, in
1.6 ! misho 2118: ** which case the trigger setting is not reported back.
! 2119: **
! 2120: ** <p>Originally this option disabled all triggers. ^(However, since
! 2121: ** SQLite version 3.35.0, TEMP triggers are still allowed even if
! 2122: ** this option is off. So, in other words, this option now only disables
! 2123: ** triggers in the main database schema or in the schemas of ATTACH-ed
! 2124: ** databases.)^ </dd>
1.2 misho 2125: **
1.5 misho 2126: ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2127: ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2128: ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2129: ** There should be two additional arguments.
2130: ** The first argument is an integer which is 0 to disable views,
2131: ** positive to enable views or negative to leave the setting unchanged.
2132: ** The second parameter is a pointer to an integer into which
2133: ** is written 0 or 1 to indicate whether views are disabled or enabled
2134: ** following this call. The second parameter may be a NULL pointer, in
1.6 ! misho 2135: ** which case the view setting is not reported back.
! 2136: **
! 2137: ** <p>Originally this option disabled all views. ^(However, since
! 2138: ** SQLite version 3.35.0, TEMP views are still allowed even if
! 2139: ** this option is off. So, in other words, this option now only disables
! 2140: ** views in the main database schema or in the schemas of ATTACH-ed
! 2141: ** databases.)^ </dd>
1.5 misho 2142: **
2143: ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
1.4 misho 2144: ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
1.5 misho 2145: ** <dd> ^This option is used to enable or disable the
2146: ** [fts3_tokenizer()] function which is part of the
1.4 misho 2147: ** [FTS3] full-text search engine extension.
2148: ** There should be two additional arguments.
2149: ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2150: ** positive to enable fts3_tokenizer() or negative to leave the setting
2151: ** unchanged.
2152: ** The second parameter is a pointer to an integer into which
2153: ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2154: ** following this call. The second parameter may be a NULL pointer, in
2155: ** which case the new setting is not reported back. </dd>
2156: **
1.5 misho 2157: ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
1.4 misho 2158: ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2159: ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2160: ** interface independently of the [load_extension()] SQL function.
2161: ** The [sqlite3_enable_load_extension()] API enables or disables both the
2162: ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2163: ** There should be two additional arguments.
2164: ** When the first argument to this interface is 1, then only the C-API is
2165: ** enabled and the SQL function remains disabled. If the first argument to
2166: ** this interface is 0, then both the C-API and the SQL function are disabled.
2167: ** If the first argument is -1, then no changes are made to state of either the
2168: ** C-API or the SQL function.
2169: ** The second parameter is a pointer to an integer into which
2170: ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2171: ** is disabled or enabled following this call. The second parameter may
2172: ** be a NULL pointer, in which case the new setting is not reported back.
2173: ** </dd>
2174: **
1.5 misho 2175: ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2176: ** <dd> ^This option is used to change the name of the "main" database
2177: ** schema. ^The sole argument is a pointer to a constant UTF8 string
2178: ** which will become the new schema name in place of "main". ^SQLite
2179: ** does not make a copy of the new main schema name string, so the application
2180: ** must ensure that the argument passed into this DBCONFIG option is unchanged
2181: ** until after the database connection closes.
2182: ** </dd>
2183: **
2184: ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2185: ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2186: ** <dd> Usually, when a database in wal mode is closed or detached from a
2187: ** database handle, SQLite checks if this will mean that there are now no
2188: ** connections at all to the database. If so, it performs a checkpoint
2189: ** operation before closing the connection. This option may be used to
2190: ** override this behaviour. The first parameter passed to this operation
2191: ** is an integer - positive to disable checkpoints-on-close, or zero (the
2192: ** default) to enable them, and negative to leave the setting unchanged.
2193: ** The second parameter is a pointer to an integer
2194: ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2195: ** have been disabled - 0 if they are not disabled, 1 if they are.
2196: ** </dd>
2197: **
2198: ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2199: ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2200: ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2201: ** a single SQL query statement will always use the same algorithm regardless
2202: ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2203: ** that look at the values of bound parameters, which can make some queries
2204: ** slower. But the QPSG has the advantage of more predictable behavior. With
2205: ** the QPSG active, SQLite will always use the same query plan in the field as
2206: ** was used during testing in the lab.
2207: ** The first argument to this setting is an integer which is 0 to disable
2208: ** the QPSG, positive to enable QPSG, or negative to leave the setting
2209: ** unchanged. The second parameter is a pointer to an integer into which
2210: ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2211: ** following this call.
2212: ** </dd>
2213: **
2214: ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2215: ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2216: ** include output for any operations performed by trigger programs. This
2217: ** option is used to set or clear (the default) a flag that governs this
2218: ** behavior. The first parameter passed to this operation is an integer -
2219: ** positive to enable output for trigger programs, or zero to disable it,
2220: ** or negative to leave the setting unchanged.
2221: ** The second parameter is a pointer to an integer into which is written
2222: ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2223: ** it is not disabled, 1 if it is.
2224: ** </dd>
2225: **
2226: ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2227: ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2228: ** [VACUUM] in order to reset a database back to an empty database
2229: ** with no schema and no content. The following process works even for
2230: ** a badly corrupted database file:
2231: ** <ol>
2232: ** <li> If the database connection is newly opened, make sure it has read the
2233: ** database schema by preparing then discarding some query against the
2234: ** database, or calling sqlite3_table_column_metadata(), ignoring any
2235: ** errors. This step is only necessary if the application desires to keep
2236: ** the database in WAL mode after the reset if it was in WAL mode before
2237: ** the reset.
2238: ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2239: ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2240: ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2241: ** </ol>
2242: ** Because resetting a database is destructive and irreversible, the
2243: ** process requires the use of this obscure API and multiple steps to help
2244: ** ensure that it does not happen by accident.
2245: **
2246: ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2247: ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2248: ** "defensive" flag for a database connection. When the defensive
2249: ** flag is enabled, language features that allow ordinary SQL to
2250: ** deliberately corrupt the database file are disabled. The disabled
2251: ** features include but are not limited to the following:
2252: ** <ul>
2253: ** <li> The [PRAGMA writable_schema=ON] statement.
2254: ** <li> The [PRAGMA journal_mode=OFF] statement.
2255: ** <li> Writes to the [sqlite_dbpage] virtual table.
2256: ** <li> Direct writes to [shadow tables].
2257: ** </ul>
2258: ** </dd>
2259: **
2260: ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2261: ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2262: ** "writable_schema" flag. This has the same effect and is logically equivalent
2263: ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2264: ** The first argument to this setting is an integer which is 0 to disable
2265: ** the writable_schema, positive to enable writable_schema, or negative to
2266: ** leave the setting unchanged. The second parameter is a pointer to an
2267: ** integer into which is written 0 or 1 to indicate whether the writable_schema
2268: ** is enabled or disabled following this call.
2269: ** </dd>
2270: **
2271: ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2272: ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2273: ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2274: ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2275: ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2276: ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2277: ** additional information. This feature can also be turned on and off
2278: ** using the [PRAGMA legacy_alter_table] statement.
2279: ** </dd>
2280: **
2281: ** [[SQLITE_DBCONFIG_DQS_DML]]
2282: ** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2283: ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2284: ** the legacy [double-quoted string literal] misfeature for DML statements
2285: ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2286: ** default value of this setting is determined by the [-DSQLITE_DQS]
2287: ** compile-time option.
2288: ** </dd>
2289: **
2290: ** [[SQLITE_DBCONFIG_DQS_DDL]]
2291: ** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2292: ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2293: ** the legacy [double-quoted string literal] misfeature for DDL statements,
2294: ** such as CREATE TABLE and CREATE INDEX. The
2295: ** default value of this setting is determined by the [-DSQLITE_DQS]
2296: ** compile-time option.
2297: ** </dd>
2298: **
2299: ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2300: ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2301: ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2302: ** assume that database schemas are untainted by malicious content.
2303: ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2304: ** takes additional defensive steps to protect the application from harm
2305: ** including:
2306: ** <ul>
2307: ** <li> Prohibit the use of SQL functions inside triggers, views,
2308: ** CHECK constraints, DEFAULT clauses, expression indexes,
2309: ** partial indexes, or generated columns
2310: ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2311: ** <li> Prohibit the use of virtual tables inside of triggers or views
2312: ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2313: ** </ul>
2314: ** This setting defaults to "on" for legacy compatibility, however
2315: ** all applications are advised to turn it off if possible. This setting
2316: ** can also be controlled using the [PRAGMA trusted_schema] statement.
2317: ** </dd>
2318: **
2319: ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2320: ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2321: ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2322: ** the legacy file format flag. When activated, this flag causes all newly
2323: ** created database file to have a schema format version number (the 4-byte
2324: ** integer found at offset 44 into the database header) of 1. This in turn
2325: ** means that the resulting database file will be readable and writable by
2326: ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2327: ** newly created databases are generally not understandable by SQLite versions
2328: ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2329: ** is now scarcely any need to generated database files that are compatible
2330: ** all the way back to version 3.0.0, and so this setting is of little
2331: ** practical use, but is provided so that SQLite can continue to claim the
2332: ** ability to generate new database files that are compatible with version
2333: ** 3.0.0.
2334: ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2335: ** the [VACUUM] command will fail with an obscure error when attempting to
2336: ** process a table with generated columns and a descending index. This is
2337: ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2338: ** either generated columns or decending indexes.
2339: ** </dd>
1.2 misho 2340: ** </dl>
2341: */
1.5 misho 2342: #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
1.4 misho 2343: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2344: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2345: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2346: #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2347: #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
1.5 misho 2348: #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2349: #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2350: #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2351: #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2352: #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2353: #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2354: #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2355: #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2356: #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2357: #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2358: #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2359: #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2360: #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
1.2 misho 2361:
2362: /*
2363: ** CAPI3REF: Enable Or Disable Extended Result Codes
1.4 misho 2364: ** METHOD: sqlite3
1.2 misho 2365: **
2366: ** ^The sqlite3_extended_result_codes() routine enables or disables the
2367: ** [extended result codes] feature of SQLite. ^The extended result
2368: ** codes are disabled by default for historical compatibility.
2369: */
2370: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2371:
2372: /*
2373: ** CAPI3REF: Last Insert Rowid
1.4 misho 2374: ** METHOD: sqlite3
1.2 misho 2375: **
1.4 misho 2376: ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2377: ** has a unique 64-bit signed
1.2 misho 2378: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2379: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2380: ** names are not also used by explicitly declared columns. ^If
2381: ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2382: ** is another alias for the rowid.
2383: **
1.5 misho 2384: ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2385: ** the most recent successful [INSERT] into a rowid table or [virtual table]
2386: ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2387: ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2388: ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2389: ** zero.
2390: **
2391: ** As well as being set automatically as rows are inserted into database
2392: ** tables, the value returned by this function may be set explicitly by
2393: ** [sqlite3_set_last_insert_rowid()]
2394: **
2395: ** Some virtual table implementations may INSERT rows into rowid tables as
2396: ** part of committing a transaction (e.g. to flush data accumulated in memory
2397: ** to disk). In this case subsequent calls to this function return the rowid
2398: ** associated with these internal INSERT operations, which leads to
2399: ** unintuitive results. Virtual table implementations that do write to rowid
2400: ** tables in this way can avoid this problem by restoring the original
2401: ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2402: ** control to the user.
2403: **
2404: ** ^(If an [INSERT] occurs within a trigger then this routine will
2405: ** return the [rowid] of the inserted row as long as the trigger is
2406: ** running. Once the trigger program ends, the value returned
2407: ** by this routine reverts to what it was before the trigger was fired.)^
1.2 misho 2408: **
2409: ** ^An [INSERT] that fails due to a constraint violation is not a
2410: ** successful [INSERT] and does not change the value returned by this
2411: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2412: ** and INSERT OR ABORT make no changes to the return value of this
2413: ** routine when their insertion fails. ^(When INSERT OR REPLACE
2414: ** encounters a constraint violation, it does not fail. The
2415: ** INSERT continues to completion after deleting rows that caused
2416: ** the constraint problem so INSERT OR REPLACE will always change
2417: ** the return value of this interface.)^
2418: **
2419: ** ^For the purposes of this routine, an [INSERT] is considered to
2420: ** be successful even if it is subsequently rolled back.
2421: **
2422: ** This function is accessible to SQL statements via the
2423: ** [last_insert_rowid() SQL function].
2424: **
2425: ** If a separate thread performs a new [INSERT] on the same
2426: ** database connection while the [sqlite3_last_insert_rowid()]
2427: ** function is running and thus changes the last insert [rowid],
2428: ** then the value returned by [sqlite3_last_insert_rowid()] is
2429: ** unpredictable and might not equal either the old or the new
2430: ** last insert [rowid].
2431: */
2432: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2433:
2434: /*
1.5 misho 2435: ** CAPI3REF: Set the Last Insert Rowid value.
2436: ** METHOD: sqlite3
2437: **
2438: ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2439: ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2440: ** without inserting a row into the database.
2441: */
2442: SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2443:
2444: /*
1.2 misho 2445: ** CAPI3REF: Count The Number Of Rows Modified
1.4 misho 2446: ** METHOD: sqlite3
1.2 misho 2447: **
1.4 misho 2448: ** ^This function returns the number of rows modified, inserted or
2449: ** deleted by the most recently completed INSERT, UPDATE or DELETE
2450: ** statement on the database connection specified by the only parameter.
2451: ** ^Executing any other type of SQL statement does not modify the value
2452: ** returned by this function.
2453: **
2454: ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
1.5 misho 2455: ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
1.4 misho 2456: ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
1.5 misho 2457: **
2458: ** Changes to a view that are intercepted by
2459: ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2460: ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2461: ** DELETE statement run on a view is always zero. Only changes made to real
1.4 misho 2462: ** tables are counted.
2463: **
2464: ** Things are more complicated if the sqlite3_changes() function is
2465: ** executed while a trigger program is running. This may happen if the
2466: ** program uses the [changes() SQL function], or if some other callback
2467: ** function invokes sqlite3_changes() directly. Essentially:
1.5 misho 2468: **
1.4 misho 2469: ** <ul>
2470: ** <li> ^(Before entering a trigger program the value returned by
1.5 misho 2471: ** sqlite3_changes() function is saved. After the trigger program
1.4 misho 2472: ** has finished, the original value is restored.)^
1.5 misho 2473: **
2474: ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2475: ** statement sets the value returned by sqlite3_changes()
2476: ** upon completion as normal. Of course, this value will not include
2477: ** any changes performed by sub-triggers, as the sqlite3_changes()
1.4 misho 2478: ** value will be saved and restored after each sub-trigger has run.)^
2479: ** </ul>
1.5 misho 2480: **
1.4 misho 2481: ** ^This means that if the changes() SQL function (or similar) is used
1.5 misho 2482: ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
1.4 misho 2483: ** returns the value as set when the calling statement began executing.
1.5 misho 2484: ** ^If it is used by the second or subsequent such statement within a trigger
2485: ** program, the value returned reflects the number of rows modified by the
1.4 misho 2486: ** previous INSERT, UPDATE or DELETE statement within the same trigger.
1.2 misho 2487: **
2488: ** If a separate thread makes changes on the same database connection
2489: ** while [sqlite3_changes()] is running then the value returned
2490: ** is unpredictable and not meaningful.
1.5 misho 2491: **
2492: ** See also:
2493: ** <ul>
2494: ** <li> the [sqlite3_total_changes()] interface
2495: ** <li> the [count_changes pragma]
2496: ** <li> the [changes() SQL function]
2497: ** <li> the [data_version pragma]
2498: ** </ul>
1.2 misho 2499: */
2500: SQLITE_API int sqlite3_changes(sqlite3*);
2501:
2502: /*
2503: ** CAPI3REF: Total Number Of Rows Modified
1.4 misho 2504: ** METHOD: sqlite3
1.2 misho 2505: **
1.4 misho 2506: ** ^This function returns the total number of rows inserted, modified or
2507: ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2508: ** since the database connection was opened, including those executed as
2509: ** part of trigger programs. ^Executing any other type of SQL statement
2510: ** does not affect the value returned by sqlite3_total_changes().
1.5 misho 2511: **
1.4 misho 2512: ** ^Changes made as part of [foreign key actions] are included in the
2513: ** count, but those made as part of REPLACE constraint resolution are
1.5 misho 2514: ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
1.4 misho 2515: ** are not counted.
1.5 misho 2516: **
2517: ** The [sqlite3_total_changes(D)] interface only reports the number
2518: ** of rows that changed due to SQL statement run against database
2519: ** connection D. Any changes by other database connections are ignored.
2520: ** To detect changes against a database file from other database
2521: ** connections use the [PRAGMA data_version] command or the
2522: ** [SQLITE_FCNTL_DATA_VERSION] [file control].
1.2 misho 2523: **
2524: ** If a separate thread makes changes on the same database connection
2525: ** while [sqlite3_total_changes()] is running then the value
2526: ** returned is unpredictable and not meaningful.
1.5 misho 2527: **
2528: ** See also:
2529: ** <ul>
2530: ** <li> the [sqlite3_changes()] interface
2531: ** <li> the [count_changes pragma]
2532: ** <li> the [changes() SQL function]
2533: ** <li> the [data_version pragma]
2534: ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2535: ** </ul>
1.2 misho 2536: */
2537: SQLITE_API int sqlite3_total_changes(sqlite3*);
2538:
2539: /*
2540: ** CAPI3REF: Interrupt A Long-Running Query
1.4 misho 2541: ** METHOD: sqlite3
1.2 misho 2542: **
2543: ** ^This function causes any pending database operation to abort and
2544: ** return at its earliest opportunity. This routine is typically
2545: ** called in response to a user action such as pressing "Cancel"
2546: ** or Ctrl-C where the user wants a long query operation to halt
2547: ** immediately.
2548: **
2549: ** ^It is safe to call this routine from a thread different from the
2550: ** thread that is currently running the database operation. But it
2551: ** is not safe to call this routine with a [database connection] that
2552: ** is closed or might close before sqlite3_interrupt() returns.
2553: **
2554: ** ^If an SQL operation is very nearly finished at the time when
2555: ** sqlite3_interrupt() is called, then it might not have an opportunity
2556: ** to be interrupted and might continue to completion.
2557: **
2558: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2559: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2560: ** that is inside an explicit transaction, then the entire transaction
2561: ** will be rolled back automatically.
2562: **
2563: ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2564: ** SQL statements on [database connection] D complete. ^Any new SQL statements
1.5 misho 2565: ** that are started after the sqlite3_interrupt() call and before the
2566: ** running statement count reaches zero are interrupted as if they had been
1.2 misho 2567: ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2568: ** that are started after the running statement count reaches zero are
2569: ** not effected by the sqlite3_interrupt().
2570: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2571: ** SQL statements is a no-op and has no effect on SQL statements
2572: ** that are started after the sqlite3_interrupt() call returns.
2573: */
2574: SQLITE_API void sqlite3_interrupt(sqlite3*);
2575:
2576: /*
2577: ** CAPI3REF: Determine If An SQL Statement Is Complete
2578: **
2579: ** These routines are useful during command-line input to determine if the
2580: ** currently entered text seems to form a complete SQL statement or
2581: ** if additional input is needed before sending the text into
2582: ** SQLite for parsing. ^These routines return 1 if the input string
2583: ** appears to be a complete SQL statement. ^A statement is judged to be
2584: ** complete if it ends with a semicolon token and is not a prefix of a
2585: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2586: ** string literals or quoted identifier names or comments are not
2587: ** independent tokens (they are part of the token in which they are
2588: ** embedded) and thus do not count as a statement terminator. ^Whitespace
2589: ** and comments that follow the final semicolon are ignored.
2590: **
2591: ** ^These routines return 0 if the statement is incomplete. ^If a
2592: ** memory allocation fails, then SQLITE_NOMEM is returned.
2593: **
2594: ** ^These routines do not parse the SQL statements thus
2595: ** will not detect syntactically incorrect SQL.
2596: **
1.5 misho 2597: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
1.2 misho 2598: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2599: ** automatically by sqlite3_complete16(). If that initialization fails,
2600: ** then the return value from sqlite3_complete16() will be non-zero
2601: ** regardless of whether or not the input SQL is complete.)^
2602: **
2603: ** The input to [sqlite3_complete()] must be a zero-terminated
2604: ** UTF-8 string.
2605: **
2606: ** The input to [sqlite3_complete16()] must be a zero-terminated
2607: ** UTF-16 string in native byte order.
2608: */
2609: SQLITE_API int sqlite3_complete(const char *sql);
2610: SQLITE_API int sqlite3_complete16(const void *sql);
2611:
2612: /*
2613: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
1.4 misho 2614: ** KEYWORDS: {busy-handler callback} {busy handler}
2615: ** METHOD: sqlite3
1.2 misho 2616: **
1.4 misho 2617: ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2618: ** that might be invoked with argument P whenever
2619: ** an attempt is made to access a database table associated with
2620: ** [database connection] D when another thread
2621: ** or process has the table locked.
2622: ** The sqlite3_busy_handler() interface is used to implement
2623: ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
1.2 misho 2624: **
1.4 misho 2625: ** ^If the busy callback is NULL, then [SQLITE_BUSY]
1.2 misho 2626: ** is returned immediately upon encountering the lock. ^If the busy callback
2627: ** is not NULL, then the callback might be invoked with two arguments.
2628: **
2629: ** ^The first argument to the busy handler is a copy of the void* pointer which
2630: ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2631: ** the busy handler callback is the number of times that the busy handler has
1.4 misho 2632: ** been invoked previously for the same locking event. ^If the
1.2 misho 2633: ** busy callback returns 0, then no additional attempts are made to
1.4 misho 2634: ** access the database and [SQLITE_BUSY] is returned
2635: ** to the application.
1.2 misho 2636: ** ^If the callback returns non-zero, then another attempt
1.4 misho 2637: ** is made to access the database and the cycle repeats.
1.2 misho 2638: **
2639: ** The presence of a busy handler does not guarantee that it will be invoked
2640: ** when there is lock contention. ^If SQLite determines that invoking the busy
2641: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1.5 misho 2642: ** to the application instead of invoking the
1.4 misho 2643: ** busy handler.
1.2 misho 2644: ** Consider a scenario where one process is holding a read lock that
2645: ** it is trying to promote to a reserved lock and
2646: ** a second process is holding a reserved lock that it is trying
2647: ** to promote to an exclusive lock. The first process cannot proceed
2648: ** because it is blocked by the second and the second process cannot
2649: ** proceed because it is blocked by the first. If both processes
2650: ** invoke the busy handlers, neither will make any progress. Therefore,
2651: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2652: ** will induce the first process to release its read lock and allow
2653: ** the second process to proceed.
2654: **
2655: ** ^The default busy callback is NULL.
2656: **
2657: ** ^(There can only be a single busy handler defined for each
2658: ** [database connection]. Setting a new busy handler clears any
2659: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
1.4 misho 2660: ** or evaluating [PRAGMA busy_timeout=N] will change the
2661: ** busy handler and thus clear any previously set busy handler.
1.2 misho 2662: **
2663: ** The busy callback should not take any actions which modify the
1.4 misho 2664: ** database connection that invoked the busy handler. In other words,
2665: ** the busy handler is not reentrant. Any such actions
1.2 misho 2666: ** result in undefined behavior.
1.5 misho 2667: **
1.2 misho 2668: ** A busy handler must not close the database connection
2669: ** or [prepared statement] that invoked the busy handler.
2670: */
1.4 misho 2671: SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
1.2 misho 2672:
2673: /*
2674: ** CAPI3REF: Set A Busy Timeout
1.4 misho 2675: ** METHOD: sqlite3
1.2 misho 2676: **
2677: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2678: ** for a specified amount of time when a table is locked. ^The handler
2679: ** will sleep multiple times until at least "ms" milliseconds of sleeping
2680: ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2681: ** the handler returns 0 which causes [sqlite3_step()] to return
1.4 misho 2682: ** [SQLITE_BUSY].
1.2 misho 2683: **
2684: ** ^Calling this routine with an argument less than or equal to zero
2685: ** turns off all busy handlers.
2686: **
2687: ** ^(There can only be a single busy handler for a particular
1.4 misho 2688: ** [database connection] at any given moment. If another busy handler
1.2 misho 2689: ** was defined (using [sqlite3_busy_handler()]) prior to calling
2690: ** this routine, that other busy handler is cleared.)^
1.4 misho 2691: **
2692: ** See also: [PRAGMA busy_timeout]
1.2 misho 2693: */
2694: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2695:
2696: /*
2697: ** CAPI3REF: Convenience Routines For Running Queries
1.4 misho 2698: ** METHOD: sqlite3
1.2 misho 2699: **
2700: ** This is a legacy interface that is preserved for backwards compatibility.
2701: ** Use of this interface is not recommended.
2702: **
2703: ** Definition: A <b>result table</b> is memory data structure created by the
2704: ** [sqlite3_get_table()] interface. A result table records the
2705: ** complete query results from one or more queries.
2706: **
2707: ** The table conceptually has a number of rows and columns. But
2708: ** these numbers are not part of the result table itself. These
2709: ** numbers are obtained separately. Let N be the number of rows
2710: ** and M be the number of columns.
2711: **
2712: ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2713: ** There are (N+1)*M elements in the array. The first M pointers point
2714: ** to zero-terminated strings that contain the names of the columns.
2715: ** The remaining entries all point to query results. NULL values result
2716: ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2717: ** string representation as returned by [sqlite3_column_text()].
2718: **
2719: ** A result table might consist of one or more memory allocations.
2720: ** It is not safe to pass a result table directly to [sqlite3_free()].
2721: ** A result table should be deallocated using [sqlite3_free_table()].
2722: **
2723: ** ^(As an example of the result table format, suppose a query result
2724: ** is as follows:
2725: **
2726: ** <blockquote><pre>
2727: ** Name | Age
2728: ** -----------------------
2729: ** Alice | 43
2730: ** Bob | 28
2731: ** Cindy | 21
2732: ** </pre></blockquote>
2733: **
1.5 misho 2734: ** There are two columns (M==2) and three rows (N==3). Thus the
1.2 misho 2735: ** result table has 8 entries. Suppose the result table is stored
1.5 misho 2736: ** in an array named azResult. Then azResult holds this content:
1.2 misho 2737: **
2738: ** <blockquote><pre>
2739: ** azResult[0] = "Name";
2740: ** azResult[1] = "Age";
2741: ** azResult[2] = "Alice";
2742: ** azResult[3] = "43";
2743: ** azResult[4] = "Bob";
2744: ** azResult[5] = "28";
2745: ** azResult[6] = "Cindy";
2746: ** azResult[7] = "21";
2747: ** </pre></blockquote>)^
2748: **
2749: ** ^The sqlite3_get_table() function evaluates one or more
2750: ** semicolon-separated SQL statements in the zero-terminated UTF-8
2751: ** string of its 2nd parameter and returns a result table to the
2752: ** pointer given in its 3rd parameter.
2753: **
2754: ** After the application has finished with the result from sqlite3_get_table(),
2755: ** it must pass the result table pointer to sqlite3_free_table() in order to
2756: ** release the memory that was malloced. Because of the way the
2757: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2758: ** function must not try to call [sqlite3_free()] directly. Only
2759: ** [sqlite3_free_table()] is able to release the memory properly and safely.
2760: **
2761: ** The sqlite3_get_table() interface is implemented as a wrapper around
2762: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2763: ** to any internal data structures of SQLite. It uses only the public
2764: ** interface defined here. As a consequence, errors that occur in the
2765: ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2766: ** reflected in subsequent calls to [sqlite3_errcode()] or
2767: ** [sqlite3_errmsg()].
2768: */
2769: SQLITE_API int sqlite3_get_table(
2770: sqlite3 *db, /* An open database */
2771: const char *zSql, /* SQL to be evaluated */
2772: char ***pazResult, /* Results of the query */
2773: int *pnRow, /* Number of result rows written here */
2774: int *pnColumn, /* Number of result columns written here */
2775: char **pzErrmsg /* Error msg written here */
2776: );
2777: SQLITE_API void sqlite3_free_table(char **result);
2778:
2779: /*
2780: ** CAPI3REF: Formatted String Printing Functions
2781: **
2782: ** These routines are work-alikes of the "printf()" family of functions
2783: ** from the standard C library.
1.5 misho 2784: ** These routines understand most of the common formatting options from
2785: ** the standard library printf()
2786: ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2787: ** See the [built-in printf()] documentation for details.
1.2 misho 2788: **
2789: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
1.5 misho 2790: ** results into memory obtained from [sqlite3_malloc64()].
1.2 misho 2791: ** The strings returned by these two routines should be
2792: ** released by [sqlite3_free()]. ^Both routines return a
1.5 misho 2793: ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
1.2 misho 2794: ** memory to hold the resulting string.
2795: **
2796: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2797: ** the standard C library. The result is written into the
2798: ** buffer supplied as the second parameter whose size is given by
2799: ** the first parameter. Note that the order of the
2800: ** first two parameters is reversed from snprintf().)^ This is an
2801: ** historical accident that cannot be fixed without breaking
2802: ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2803: ** returns a pointer to its buffer instead of the number of
2804: ** characters actually written into the buffer.)^ We admit that
2805: ** the number of characters written would be a more useful return
2806: ** value but we cannot change the implementation of sqlite3_snprintf()
2807: ** now without breaking compatibility.
2808: **
2809: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2810: ** guarantees that the buffer is always zero-terminated. ^The first
2811: ** parameter "n" is the total size of the buffer, including space for
2812: ** the zero terminator. So the longest string that can be completely
2813: ** written will be n-1 characters.
2814: **
2815: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2816: **
1.5 misho 2817: ** See also: [built-in printf()], [printf() SQL function]
1.2 misho 2818: */
2819: SQLITE_API char *sqlite3_mprintf(const char*,...);
2820: SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2821: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2822: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2823:
2824: /*
2825: ** CAPI3REF: Memory Allocation Subsystem
2826: **
2827: ** The SQLite core uses these three routines for all of its own
2828: ** internal memory allocation needs. "Core" in the previous sentence
1.5 misho 2829: ** does not include operating-system specific [VFS] implementation. The
1.2 misho 2830: ** Windows VFS uses native malloc() and free() for some operations.
2831: **
2832: ** ^The sqlite3_malloc() routine returns a pointer to a block
2833: ** of memory at least N bytes in length, where N is the parameter.
2834: ** ^If sqlite3_malloc() is unable to obtain sufficient free
2835: ** memory, it returns a NULL pointer. ^If the parameter N to
2836: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2837: ** a NULL pointer.
2838: **
1.4 misho 2839: ** ^The sqlite3_malloc64(N) routine works just like
2840: ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2841: ** of a signed 32-bit integer.
2842: **
1.2 misho 2843: ** ^Calling sqlite3_free() with a pointer previously returned
2844: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2845: ** that it might be reused. ^The sqlite3_free() routine is
2846: ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2847: ** to sqlite3_free() is harmless. After being freed, memory
2848: ** should neither be read nor written. Even reading previously freed
2849: ** memory might result in a segmentation fault or other severe error.
2850: ** Memory corruption, a segmentation fault, or other severe error
2851: ** might result if sqlite3_free() is called with a non-NULL pointer that
2852: ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2853: **
1.4 misho 2854: ** ^The sqlite3_realloc(X,N) interface attempts to resize a
2855: ** prior memory allocation X to be at least N bytes.
2856: ** ^If the X parameter to sqlite3_realloc(X,N)
1.2 misho 2857: ** is a NULL pointer then its behavior is identical to calling
1.4 misho 2858: ** sqlite3_malloc(N).
2859: ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
1.2 misho 2860: ** negative then the behavior is exactly the same as calling
1.4 misho 2861: ** sqlite3_free(X).
2862: ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2863: ** of at least N bytes in size or NULL if insufficient memory is available.
1.2 misho 2864: ** ^If M is the size of the prior allocation, then min(N,M) bytes
2865: ** of the prior allocation are copied into the beginning of buffer returned
1.4 misho 2866: ** by sqlite3_realloc(X,N) and the prior allocation is freed.
2867: ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2868: ** prior allocation is not freed.
2869: **
2870: ** ^The sqlite3_realloc64(X,N) interfaces works the same as
2871: ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2872: ** of a 32-bit signed integer.
2873: **
2874: ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2875: ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2876: ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2877: ** ^The value returned by sqlite3_msize(X) might be larger than the number
2878: ** of bytes requested when X was allocated. ^If X is a NULL pointer then
2879: ** sqlite3_msize(X) returns zero. If X points to something that is not
2880: ** the beginning of memory allocation, or if it points to a formerly
2881: ** valid memory allocation that has now been freed, then the behavior
2882: ** of sqlite3_msize(X) is undefined and possibly harmful.
1.2 misho 2883: **
1.4 misho 2884: ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2885: ** sqlite3_malloc64(), and sqlite3_realloc64()
1.2 misho 2886: ** is always aligned to at least an 8 byte boundary, or to a
2887: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2888: ** option is used.
2889: **
2890: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2891: ** must be either NULL or else pointers obtained from a prior
2892: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2893: ** not yet been released.
2894: **
2895: ** The application must not read or write any part of
2896: ** a block of memory after it has been released using
2897: ** [sqlite3_free()] or [sqlite3_realloc()].
2898: */
2899: SQLITE_API void *sqlite3_malloc(int);
1.4 misho 2900: SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
1.2 misho 2901: SQLITE_API void *sqlite3_realloc(void*, int);
1.4 misho 2902: SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
1.2 misho 2903: SQLITE_API void sqlite3_free(void*);
1.4 misho 2904: SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
1.2 misho 2905:
2906: /*
2907: ** CAPI3REF: Memory Allocator Statistics
2908: **
2909: ** SQLite provides these two interfaces for reporting on the status
2910: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2911: ** routines, which form the built-in memory allocation subsystem.
2912: **
2913: ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2914: ** of memory currently outstanding (malloced but not freed).
2915: ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2916: ** value of [sqlite3_memory_used()] since the high-water mark
2917: ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2918: ** [sqlite3_memory_highwater()] include any overhead
2919: ** added by SQLite in its implementation of [sqlite3_malloc()],
2920: ** but not overhead added by the any underlying system library
2921: ** routines that [sqlite3_malloc()] may call.
2922: **
2923: ** ^The memory high-water mark is reset to the current value of
2924: ** [sqlite3_memory_used()] if and only if the parameter to
2925: ** [sqlite3_memory_highwater()] is true. ^The value returned
2926: ** by [sqlite3_memory_highwater(1)] is the high-water mark
2927: ** prior to the reset.
2928: */
2929: SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2930: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2931:
2932: /*
2933: ** CAPI3REF: Pseudo-Random Number Generator
2934: **
2935: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2936: ** select random [ROWID | ROWIDs] when inserting new records into a table that
2937: ** already uses the largest possible [ROWID]. The PRNG is also used for
1.5 misho 2938: ** the built-in random() and randomblob() SQL functions. This interface allows
1.2 misho 2939: ** applications to access the same PRNG for other purposes.
2940: **
2941: ** ^A call to this routine stores N bytes of randomness into buffer P.
1.4 misho 2942: ** ^The P parameter can be a NULL pointer.
1.2 misho 2943: **
1.4 misho 2944: ** ^If this routine has not been previously called or if the previous
2945: ** call had N less than one or a NULL pointer for P, then the PRNG is
2946: ** seeded using randomness obtained from the xRandomness method of
2947: ** the default [sqlite3_vfs] object.
2948: ** ^If the previous call to this routine had an N of 1 or more and a
2949: ** non-NULL P then the pseudo-randomness is generated
1.2 misho 2950: ** internally and without recourse to the [sqlite3_vfs] xRandomness
2951: ** method.
2952: */
2953: SQLITE_API void sqlite3_randomness(int N, void *P);
2954:
2955: /*
2956: ** CAPI3REF: Compile-Time Authorization Callbacks
1.4 misho 2957: ** METHOD: sqlite3
1.5 misho 2958: ** KEYWORDS: {authorizer callback}
1.2 misho 2959: **
2960: ** ^This routine registers an authorizer callback with a particular
2961: ** [database connection], supplied in the first argument.
2962: ** ^The authorizer callback is invoked as SQL statements are being compiled
2963: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
1.5 misho 2964: ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2965: ** and [sqlite3_prepare16_v3()]. ^At various
1.2 misho 2966: ** points during the compilation process, as logic is being created
2967: ** to perform various actions, the authorizer callback is invoked to
2968: ** see if those actions are allowed. ^The authorizer callback should
2969: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2970: ** specific action but allow the SQL statement to continue to be
2971: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2972: ** rejected with an error. ^If the authorizer callback returns
2973: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2974: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2975: ** the authorizer will fail with an error message.
2976: **
2977: ** When the callback returns [SQLITE_OK], that means the operation
2978: ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2979: ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2980: ** authorizer will fail with an error message explaining that
1.5 misho 2981: ** access is denied.
1.2 misho 2982: **
2983: ** ^The first parameter to the authorizer callback is a copy of the third
2984: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2985: ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2986: ** the particular action to be authorized. ^The third through sixth parameters
1.5 misho 2987: ** to the callback are either NULL pointers or zero-terminated strings
2988: ** that contain additional details about the action to be authorized.
2989: ** Applications must always be prepared to encounter a NULL pointer in any
2990: ** of the third through the sixth parameters of the authorization callback.
1.2 misho 2991: **
2992: ** ^If the action code is [SQLITE_READ]
2993: ** and the callback returns [SQLITE_IGNORE] then the
2994: ** [prepared statement] statement is constructed to substitute
2995: ** a NULL value in place of the table column that would have
2996: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2997: ** return can be used to deny an untrusted user access to individual
2998: ** columns of a table.
1.5 misho 2999: ** ^When a table is referenced by a [SELECT] but no column values are
3000: ** extracted from that table (for example in a query like
3001: ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3002: ** is invoked once for that table with a column name that is an empty string.
1.2 misho 3003: ** ^If the action code is [SQLITE_DELETE] and the callback returns
3004: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3005: ** [truncate optimization] is disabled and all rows are deleted individually.
3006: **
3007: ** An authorizer is used when [sqlite3_prepare | preparing]
3008: ** SQL statements from an untrusted source, to ensure that the SQL statements
3009: ** do not try to access data they are not allowed to see, or that they do not
3010: ** try to execute malicious statements that damage the database. For
3011: ** example, an application may allow a user to enter arbitrary
3012: ** SQL queries for evaluation by a database. But the application does
3013: ** not want the user to be able to make arbitrary changes to the
3014: ** database. An authorizer could then be put in place while the
3015: ** user-entered SQL is being [sqlite3_prepare | prepared] that
3016: ** disallows everything except [SELECT] statements.
3017: **
3018: ** Applications that need to process SQL from untrusted sources
3019: ** might also consider lowering resource limits using [sqlite3_limit()]
3020: ** and limiting database size using the [max_page_count] [PRAGMA]
3021: ** in addition to using an authorizer.
3022: **
3023: ** ^(Only a single authorizer can be in place on a database connection
3024: ** at a time. Each call to sqlite3_set_authorizer overrides the
3025: ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3026: ** The authorizer is disabled by default.
3027: **
3028: ** The authorizer callback must not do anything that will modify
3029: ** the database connection that invoked the authorizer callback.
3030: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3031: ** database connections for the meaning of "modify" in this paragraph.
3032: **
3033: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
1.5 misho 3034: ** statement might be re-prepared during [sqlite3_step()] due to a
1.2 misho 3035: ** schema change. Hence, the application should ensure that the
3036: ** correct authorizer callback remains in place during the [sqlite3_step()].
3037: **
3038: ** ^Note that the authorizer callback is invoked only during
3039: ** [sqlite3_prepare()] or its variants. Authorization is not
3040: ** performed during statement evaluation in [sqlite3_step()], unless
3041: ** as stated in the previous paragraph, sqlite3_step() invokes
3042: ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3043: */
3044: SQLITE_API int sqlite3_set_authorizer(
3045: sqlite3*,
3046: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3047: void *pUserData
3048: );
3049:
3050: /*
3051: ** CAPI3REF: Authorizer Return Codes
3052: **
3053: ** The [sqlite3_set_authorizer | authorizer callback function] must
3054: ** return either [SQLITE_OK] or one of these two constants in order
3055: ** to signal SQLite whether or not the action is permitted. See the
3056: ** [sqlite3_set_authorizer | authorizer documentation] for additional
3057: ** information.
3058: **
1.4 misho 3059: ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3060: ** returned from the [sqlite3_vtab_on_conflict()] interface.
1.2 misho 3061: */
3062: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3063: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3064:
3065: /*
3066: ** CAPI3REF: Authorizer Action Codes
3067: **
3068: ** The [sqlite3_set_authorizer()] interface registers a callback function
3069: ** that is invoked to authorize certain SQL statement actions. The
3070: ** second parameter to the callback is an integer code that specifies
3071: ** what action is being authorized. These are the integer action codes that
3072: ** the authorizer callback may be passed.
3073: **
3074: ** These action code values signify what kind of operation is to be
3075: ** authorized. The 3rd and 4th parameters to the authorization
3076: ** callback function will be parameters or NULL depending on which of these
3077: ** codes is used as the second parameter. ^(The 5th parameter to the
3078: ** authorizer callback is the name of the database ("main", "temp",
3079: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3080: ** is the name of the inner-most trigger or view that is responsible for
3081: ** the access attempt or NULL if this access attempt is directly from
3082: ** top-level SQL code.
3083: */
3084: /******************************************* 3rd ************ 4th ***********/
3085: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3086: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3087: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3088: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3089: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3090: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3091: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3092: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3093: #define SQLITE_DELETE 9 /* Table Name NULL */
3094: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3095: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3096: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3097: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3098: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3099: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3100: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3101: #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3102: #define SQLITE_INSERT 18 /* Table Name NULL */
3103: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3104: #define SQLITE_READ 20 /* Table Name Column Name */
3105: #define SQLITE_SELECT 21 /* NULL NULL */
3106: #define SQLITE_TRANSACTION 22 /* Operation NULL */
3107: #define SQLITE_UPDATE 23 /* Table Name Column Name */
3108: #define SQLITE_ATTACH 24 /* Filename NULL */
3109: #define SQLITE_DETACH 25 /* Database Name NULL */
3110: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3111: #define SQLITE_REINDEX 27 /* Index Name NULL */
3112: #define SQLITE_ANALYZE 28 /* Table Name NULL */
3113: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3114: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3115: #define SQLITE_FUNCTION 31 /* NULL Function Name */
3116: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3117: #define SQLITE_COPY 0 /* No longer used */
1.4 misho 3118: #define SQLITE_RECURSIVE 33 /* NULL NULL */
1.2 misho 3119:
3120: /*
3121: ** CAPI3REF: Tracing And Profiling Functions
1.4 misho 3122: ** METHOD: sqlite3
3123: **
3124: ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3125: ** instead of the routines described here.
1.2 misho 3126: **
3127: ** These routines register callback functions that can be used for
3128: ** tracing and profiling the execution of SQL statements.
3129: **
3130: ** ^The callback function registered by sqlite3_trace() is invoked at
3131: ** various times when an SQL statement is being run by [sqlite3_step()].
3132: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3133: ** SQL statement text as the statement first begins executing.
3134: ** ^(Additional sqlite3_trace() callbacks might occur
3135: ** as each triggered subprogram is entered. The callbacks for triggers
3136: ** contain a UTF-8 SQL comment that identifies the trigger.)^
3137: **
1.4 misho 3138: ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3139: ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3140: **
1.2 misho 3141: ** ^The callback function registered by sqlite3_profile() is invoked
3142: ** as each SQL statement finishes. ^The profile callback contains
3143: ** the original statement text and an estimate of wall-clock time
3144: ** of how long that statement took to run. ^The profile callback
3145: ** time is in units of nanoseconds, however the current implementation
3146: ** is only capable of millisecond resolution so the six least significant
3147: ** digits in the time are meaningless. Future versions of SQLite
1.5 misho 3148: ** might provide greater resolution on the profiler callback. Invoking
3149: ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3150: ** profile callback.
1.2 misho 3151: */
1.4 misho 3152: SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3153: void(*xTrace)(void*,const char*), void*);
3154: SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
1.2 misho 3155: void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3156:
3157: /*
1.4 misho 3158: ** CAPI3REF: SQL Trace Event Codes
3159: ** KEYWORDS: SQLITE_TRACE
3160: **
3161: ** These constants identify classes of events that can be monitored
1.5 misho 3162: ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3163: ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
1.4 misho 3164: ** the following constants. ^The first argument to the trace callback
3165: ** is one of the following constants.
3166: **
3167: ** New tracing constants may be added in future releases.
3168: **
3169: ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3170: ** ^The T argument is one of the integer type codes above.
3171: ** ^The C argument is a copy of the context pointer passed in as the
3172: ** fourth argument to [sqlite3_trace_v2()].
3173: ** The P and X arguments are pointers whose meanings depend on T.
3174: **
3175: ** <dl>
3176: ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3177: ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3178: ** first begins running and possibly at other times during the
3179: ** execution of the prepared statement, such as at the start of each
3180: ** trigger subprogram. ^The P argument is a pointer to the
3181: ** [prepared statement]. ^The X argument is a pointer to a string which
1.5 misho 3182: ** is the unexpanded SQL text of the prepared statement or an SQL comment
1.4 misho 3183: ** that indicates the invocation of a trigger. ^The callback can compute
3184: ** the same text that would have been returned by the legacy [sqlite3_trace()]
3185: ** interface by using the X argument when X begins with "--" and invoking
3186: ** [sqlite3_expanded_sql(P)] otherwise.
3187: **
3188: ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3189: ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3190: ** information as is provided by the [sqlite3_profile()] callback.
3191: ** ^The P argument is a pointer to the [prepared statement] and the
3192: ** X argument points to a 64-bit integer which is the estimated of
3193: ** the number of nanosecond that the prepared statement took to run.
3194: ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3195: **
3196: ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3197: ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
1.5 misho 3198: ** statement generates a single row of result.
1.4 misho 3199: ** ^The P argument is a pointer to the [prepared statement] and the
3200: ** X argument is unused.
3201: **
3202: ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3203: ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3204: ** connection closes.
3205: ** ^The P argument is a pointer to the [database connection] object
3206: ** and the X argument is unused.
3207: ** </dl>
3208: */
3209: #define SQLITE_TRACE_STMT 0x01
3210: #define SQLITE_TRACE_PROFILE 0x02
3211: #define SQLITE_TRACE_ROW 0x04
3212: #define SQLITE_TRACE_CLOSE 0x08
3213:
3214: /*
3215: ** CAPI3REF: SQL Trace Hook
3216: ** METHOD: sqlite3
3217: **
3218: ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3219: ** function X against [database connection] D, using property mask M
3220: ** and context pointer P. ^If the X callback is
3221: ** NULL or if the M mask is zero, then tracing is disabled. The
3222: ** M argument should be the bitwise OR-ed combination of
3223: ** zero or more [SQLITE_TRACE] constants.
3224: **
1.5 misho 3225: ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
1.4 misho 3226: ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3227: **
1.5 misho 3228: ** ^The X callback is invoked whenever any of the events identified by
1.4 misho 3229: ** mask M occur. ^The integer return value from the callback is currently
3230: ** ignored, though this may change in future releases. Callback
3231: ** implementations should return zero to ensure future compatibility.
3232: **
3233: ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3234: ** ^The T argument is one of the [SQLITE_TRACE]
3235: ** constants to indicate why the callback was invoked.
3236: ** ^The C argument is a copy of the context pointer.
3237: ** The P and X arguments are pointers whose meanings depend on T.
3238: **
3239: ** The sqlite3_trace_v2() interface is intended to replace the legacy
3240: ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3241: ** are deprecated.
3242: */
3243: SQLITE_API int sqlite3_trace_v2(
3244: sqlite3*,
3245: unsigned uMask,
3246: int(*xCallback)(unsigned,void*,void*,void*),
3247: void *pCtx
3248: );
3249:
3250: /*
1.2 misho 3251: ** CAPI3REF: Query Progress Callbacks
1.4 misho 3252: ** METHOD: sqlite3
1.2 misho 3253: **
3254: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3255: ** function X to be invoked periodically during long running calls to
3256: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3257: ** database connection D. An example use for this
3258: ** interface is to keep a GUI updated during a large query.
3259: **
1.5 misho 3260: ** ^The parameter P is passed through as the only parameter to the
3261: ** callback function X. ^The parameter N is the approximate number of
1.2 misho 3262: ** [virtual machine instructions] that are evaluated between successive
1.4 misho 3263: ** invocations of the callback X. ^If N is less than one then the progress
3264: ** handler is disabled.
1.2 misho 3265: **
3266: ** ^Only a single progress handler may be defined at one time per
3267: ** [database connection]; setting a new progress handler cancels the
3268: ** old one. ^Setting parameter X to NULL disables the progress handler.
3269: ** ^The progress handler is also disabled by setting N to a value less
3270: ** than 1.
3271: **
3272: ** ^If the progress callback returns non-zero, the operation is
3273: ** interrupted. This feature can be used to implement a
3274: ** "Cancel" button on a GUI progress dialog box.
3275: **
3276: ** The progress handler callback must not do anything that will modify
3277: ** the database connection that invoked the progress handler.
3278: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3279: ** database connections for the meaning of "modify" in this paragraph.
3280: **
3281: */
3282: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3283:
3284: /*
3285: ** CAPI3REF: Opening A New Database Connection
1.4 misho 3286: ** CONSTRUCTOR: sqlite3
1.2 misho 3287: **
1.5 misho 3288: ** ^These routines open an SQLite database file as specified by the
1.2 misho 3289: ** filename argument. ^The filename argument is interpreted as UTF-8 for
3290: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3291: ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3292: ** returned in *ppDb, even if an error occurs. The only exception is that
3293: ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3294: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3295: ** object.)^ ^(If the database is opened (and/or created) successfully, then
3296: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3297: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3298: ** an English language description of the error following a failure of any
3299: ** of the sqlite3_open() routines.
3300: **
1.4 misho 3301: ** ^The default encoding will be UTF-8 for databases created using
3302: ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3303: ** created using sqlite3_open16() will be UTF-16 in the native byte order.
1.2 misho 3304: **
3305: ** Whether or not an error occurs when it is opened, resources
3306: ** associated with the [database connection] handle should be released by
3307: ** passing it to [sqlite3_close()] when it is no longer required.
3308: **
3309: ** The sqlite3_open_v2() interface works like sqlite3_open()
3310: ** except that it accepts two additional parameters for additional control
3311: ** over the new database connection. ^(The flags parameter to
1.5 misho 3312: ** sqlite3_open_v2() must include, at a minimum, one of the following
3313: ** three flag combinations:)^
1.2 misho 3314: **
3315: ** <dl>
3316: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3317: ** <dd>The database is opened in read-only mode. If the database does not
3318: ** already exist, an error is returned.</dd>)^
3319: **
3320: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3321: ** <dd>The database is opened for reading and writing if possible, or reading
3322: ** only if the file is write protected by the operating system. In either
3323: ** case the database must already exist, otherwise an error is returned.</dd>)^
3324: **
3325: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3326: ** <dd>The database is opened for reading and writing, and is created if
3327: ** it does not already exist. This is the behavior that is always used for
3328: ** sqlite3_open() and sqlite3_open16().</dd>)^
3329: ** </dl>
3330: **
1.5 misho 3331: ** In addition to the required flags, the following optional flags are
3332: ** also supported:
3333: **
3334: ** <dl>
3335: ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3336: ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3337: **
3338: ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3339: ** <dd>The database will be opened as an in-memory database. The database
3340: ** is named by the "filename" argument for the purposes of cache-sharing,
3341: ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3342: ** </dd>)^
3343: **
3344: ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3345: ** <dd>The new database connection will use the "multi-thread"
3346: ** [threading mode].)^ This means that separate threads are allowed
3347: ** to use SQLite at the same time, as long as each thread is using
3348: ** a different [database connection].
3349: **
3350: ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3351: ** <dd>The new database connection will use the "serialized"
3352: ** [threading mode].)^ This means the multiple threads can safely
3353: ** attempt to use the same database connection at the same time.
3354: ** (Mutexes will block any actual concurrency, but in this mode
3355: ** there is no harm in trying.)
3356: **
3357: ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3358: ** <dd>The database is opened [shared cache] enabled, overriding
3359: ** the default shared cache setting provided by
3360: ** [sqlite3_enable_shared_cache()].)^
3361: **
3362: ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3363: ** <dd>The database is opened [shared cache] disabled, overriding
3364: ** the default shared cache setting provided by
3365: ** [sqlite3_enable_shared_cache()].)^
3366: **
3367: ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3368: ** <dd>The database filename is not allowed to be a symbolic link</dd>
3369: ** </dl>)^
3370: **
1.2 misho 3371: ** If the 3rd parameter to sqlite3_open_v2() is not one of the
1.5 misho 3372: ** required combinations shown above optionally combined with other
1.2 misho 3373: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3374: ** then the behavior is undefined.
3375: **
3376: ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3377: ** [sqlite3_vfs] object that defines the operating system interface that
3378: ** the new database connection should use. ^If the fourth parameter is
3379: ** a NULL pointer then the default [sqlite3_vfs] object is used.
3380: **
3381: ** ^If the filename is ":memory:", then a private, temporary in-memory database
3382: ** is created for the connection. ^This in-memory database will vanish when
3383: ** the database connection is closed. Future versions of SQLite might
3384: ** make use of additional special filenames that begin with the ":" character.
3385: ** It is recommended that when a database filename actually does begin with
3386: ** a ":" character you should prefix the filename with a pathname such as
3387: ** "./" to avoid ambiguity.
3388: **
3389: ** ^If the filename is an empty string, then a private, temporary
3390: ** on-disk database will be created. ^This private database will be
3391: ** automatically deleted as soon as the database connection is closed.
3392: **
3393: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3394: **
3395: ** ^If [URI filename] interpretation is enabled, and the filename argument
3396: ** begins with "file:", then the filename is interpreted as a URI. ^URI
3397: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
1.5 misho 3398: ** set in the third argument to sqlite3_open_v2(), or if it has
1.2 misho 3399: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3400: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
1.5 misho 3401: ** URI filename interpretation is turned off
1.2 misho 3402: ** by default, but future releases of SQLite might enable URI filename
3403: ** interpretation by default. See "[URI filenames]" for additional
3404: ** information.
3405: **
3406: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
1.5 misho 3407: ** authority, then it must be either an empty string or the string
3408: ** "localhost". ^If the authority is not an empty string or "localhost", an
3409: ** error is returned to the caller. ^The fragment component of a URI, if
1.2 misho 3410: ** present, is ignored.
3411: **
3412: ** ^SQLite uses the path component of the URI as the name of the disk file
1.5 misho 3413: ** which contains the database. ^If the path begins with a '/' character,
3414: ** then it is interpreted as an absolute path. ^If the path does not begin
1.2 misho 3415: ** with a '/' (meaning that the authority section is omitted from the URI)
1.5 misho 3416: ** then the path is interpreted as a relative path.
3417: ** ^(On windows, the first component of an absolute path
1.4 misho 3418: ** is a drive specification (e.g. "C:").)^
1.2 misho 3419: **
3420: ** [[core URI query parameters]]
3421: ** The query component of a URI may contain parameters that are interpreted
3422: ** either by SQLite itself, or by a [VFS | custom VFS implementation].
1.4 misho 3423: ** SQLite and its built-in [VFSes] interpret the
3424: ** following query parameters:
1.2 misho 3425: **
3426: ** <ul>
3427: ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3428: ** a VFS object that provides the operating system interface that should
3429: ** be used to access the database file on disk. ^If this option is set to
3430: ** an empty string the default VFS object is used. ^Specifying an unknown
3431: ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3432: ** present, then the VFS specified by the option takes precedence over
3433: ** the value passed as the fourth parameter to sqlite3_open_v2().
3434: **
1.3 misho 3435: ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3436: ** "rwc", or "memory". Attempting to set it to any other value is
1.5 misho 3437: ** an error)^.
3438: ** ^If "ro" is specified, then the database is opened for read-only
3439: ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3440: ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3441: ** "rw", then the database is opened for read-write (but not create)
3442: ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3443: ** been set. ^Value "rwc" is equivalent to setting both
1.3 misho 3444: ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3445: ** set to "memory" then a pure [in-memory database] that never reads
3446: ** or writes from disk is used. ^It is an error to specify a value for
3447: ** the mode parameter that is less restrictive than that specified by
3448: ** the flags passed in the third parameter to sqlite3_open_v2().
1.2 misho 3449: **
3450: ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3451: ** "private". ^Setting it to "shared" is equivalent to setting the
3452: ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
1.5 misho 3453: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
1.2 misho 3454: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3455: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
1.4 misho 3456: ** a URI filename, its value overrides any behavior requested by setting
1.2 misho 3457: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
1.4 misho 3458: **
3459: ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3460: ** [powersafe overwrite] property does or does not apply to the
3461: ** storage media on which the database file resides.
3462: **
3463: ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3464: ** which if set disables file locking in rollback journal modes. This
3465: ** is useful for accessing a database on a filesystem that does not
3466: ** support locking. Caution: Database corruption might result if two
3467: ** or more processes write to the same database and any one of those
3468: ** processes uses nolock=1.
3469: **
3470: ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3471: ** parameter that indicates that the database file is stored on
3472: ** read-only media. ^When immutable is set, SQLite assumes that the
3473: ** database file cannot be changed, even by a process with higher
3474: ** privilege, and so the database is opened read-only and all locking
3475: ** and change detection is disabled. Caution: Setting the immutable
3476: ** property on a database file that does in fact change can result
3477: ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3478: ** See also: [SQLITE_IOCAP_IMMUTABLE].
1.5 misho 3479: **
1.2 misho 3480: ** </ul>
3481: **
3482: ** ^Specifying an unknown parameter in the query component of a URI is not an
3483: ** error. Future versions of SQLite might understand additional query
3484: ** parameters. See "[query parameters with special meaning to SQLite]" for
3485: ** additional information.
3486: **
3487: ** [[URI filename examples]] <h3>URI filename examples</h3>
3488: **
3489: ** <table border="1" align=center cellpadding=5>
3490: ** <tr><th> URI filenames <th> Results
1.5 misho 3491: ** <tr><td> file:data.db <td>
1.2 misho 3492: ** Open the file "data.db" in the current directory.
3493: ** <tr><td> file:/home/fred/data.db<br>
1.5 misho 3494: ** file:///home/fred/data.db <br>
3495: ** file://localhost/home/fred/data.db <br> <td>
1.2 misho 3496: ** Open the database file "/home/fred/data.db".
1.5 misho 3497: ** <tr><td> file://darkstar/home/fred/data.db <td>
1.2 misho 3498: ** An error. "darkstar" is not a recognized authority.
1.5 misho 3499: ** <tr><td style="white-space:nowrap">
1.2 misho 3500: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3501: ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
1.5 misho 3502: ** C:. Note that the %20 escaping in this example is not strictly
1.2 misho 3503: ** necessary - space characters can be used literally
3504: ** in URI filenames.
1.5 misho 3505: ** <tr><td> file:data.db?mode=ro&cache=private <td>
1.2 misho 3506: ** Open file "data.db" in the current directory for read-only access.
3507: ** Regardless of whether or not shared-cache mode is enabled by
3508: ** default, use a private cache.
1.4 misho 3509: ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3510: ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3511: ** that uses dot-files in place of posix advisory locking.
1.5 misho 3512: ** <tr><td> file:data.db?mode=readonly <td>
1.2 misho 3513: ** An error. "readonly" is not a valid option for the "mode" parameter.
1.6 ! misho 3514: ** Use "ro" instead: "file:data.db?mode=ro".
1.2 misho 3515: ** </table>
3516: **
3517: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3518: ** query components of a URI. A hexadecimal escape sequence consists of a
1.5 misho 3519: ** percent sign - "%" - followed by exactly two hexadecimal digits
1.2 misho 3520: ** specifying an octet value. ^Before the path or query components of a
1.5 misho 3521: ** URI filename are interpreted, they are encoded using UTF-8 and all
1.2 misho 3522: ** hexadecimal escape sequences replaced by a single byte containing the
3523: ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3524: ** the results are undefined.
3525: **
3526: ** <b>Note to Windows users:</b> The encoding used for the filename argument
3527: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3528: ** codepage is currently defined. Filenames containing international
3529: ** characters must be converted to UTF-8 prior to passing them into
3530: ** sqlite3_open() or sqlite3_open_v2().
1.3 misho 3531: **
3532: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3533: ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3534: ** features that require the use of temporary files may fail.
3535: **
3536: ** See also: [sqlite3_temp_directory]
1.2 misho 3537: */
3538: SQLITE_API int sqlite3_open(
3539: const char *filename, /* Database filename (UTF-8) */
3540: sqlite3 **ppDb /* OUT: SQLite db handle */
3541: );
3542: SQLITE_API int sqlite3_open16(
3543: const void *filename, /* Database filename (UTF-16) */
3544: sqlite3 **ppDb /* OUT: SQLite db handle */
3545: );
3546: SQLITE_API int sqlite3_open_v2(
3547: const char *filename, /* Database filename (UTF-8) */
3548: sqlite3 **ppDb, /* OUT: SQLite db handle */
3549: int flags, /* Flags */
3550: const char *zVfs /* Name of VFS module to use */
3551: );
3552:
3553: /*
3554: ** CAPI3REF: Obtain Values For URI Parameters
3555: **
1.5 misho 3556: ** These are utility routines, useful to [VFS|custom VFS implementations],
3557: ** that check if a database file was a URI that contained a specific query
1.2 misho 3558: ** parameter, and if so obtains the value of that query parameter.
3559: **
1.5 misho 3560: ** The first parameter to these interfaces (hereafter referred to
3561: ** as F) must be one of:
3562: ** <ul>
3563: ** <li> A database filename pointer created by the SQLite core and
3564: ** passed into the xOpen() method of a VFS implemention, or
3565: ** <li> A filename obtained from [sqlite3_db_filename()], or
3566: ** <li> A new filename constructed using [sqlite3_create_filename()].
3567: ** </ul>
3568: ** If the F parameter is not one of the above, then the behavior is
3569: ** undefined and probably undesirable. Older versions of SQLite were
3570: ** more tolerant of invalid F parameters than newer versions.
3571: **
3572: ** If F is a suitable filename (as described in the previous paragraph)
3573: ** and if P is the name of the query parameter, then
1.2 misho 3574: ** sqlite3_uri_parameter(F,P) returns the value of the P
1.5 misho 3575: ** parameter if it exists or a NULL pointer if P does not appear as a
3576: ** query parameter on F. If P is a query parameter of F and it
1.2 misho 3577: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3578: ** a pointer to an empty string.
3579: **
3580: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3581: ** parameter and returns true (1) or false (0) according to the value
1.3 misho 3582: ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3583: ** value of query parameter P is one of "yes", "true", or "on" in any
1.5 misho 3584: ** case or if the value begins with a non-zero number. The
1.3 misho 3585: ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3586: ** query parameter P is one of "no", "false", or "off" in any case or
3587: ** if the value begins with a numeric zero. If P is not a query
1.5 misho 3588: ** parameter on F or if the value of P does not match any of the
1.3 misho 3589: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
1.2 misho 3590: **
3591: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3592: ** 64-bit signed integer and returns that integer, or D if P does not
3593: ** exist. If the value of P is something other than an integer, then
3594: ** zero is returned.
1.5 misho 3595: **
3596: ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3597: ** the value) of the N-th query parameter for filename F, or a NULL
3598: ** pointer if N is less than zero or greater than the number of query
3599: ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3600: ** the name of the first query parameter, 1 for the second parameter, and
3601: ** so forth.
3602: **
1.2 misho 3603: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3604: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
1.5 misho 3605: ** is not a database file pathname pointer that the SQLite core passed
3606: ** into the xOpen VFS method, then the behavior of this routine is undefined
3607: ** and probably undesirable.
3608: **
3609: ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3610: ** parameter can also be the name of a rollback journal file or WAL file
3611: ** in addition to the main database file. Prior to version 3.31.0, these
3612: ** routines would only work if F was the name of the main database file.
3613: ** When the F parameter is the name of the rollback journal or WAL file,
3614: ** it has access to all the same query parameters as were found on the
3615: ** main database file.
3616: **
3617: ** See the [URI filename] documentation for additional information.
1.2 misho 3618: */
3619: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3620: SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3621: SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
1.5 misho 3622: SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
1.2 misho 3623:
1.5 misho 3624: /*
3625: ** CAPI3REF: Translate filenames
3626: **
3627: ** These routines are available to [VFS|custom VFS implementations] for
3628: ** translating filenames between the main database file, the journal file,
3629: ** and the WAL file.
3630: **
3631: ** If F is the name of an sqlite database file, journal file, or WAL file
3632: ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3633: ** returns the name of the corresponding database file.
3634: **
3635: ** If F is the name of an sqlite database file, journal file, or WAL file
3636: ** passed by the SQLite core into the VFS, or if F is a database filename
3637: ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3638: ** returns the name of the corresponding rollback journal file.
3639: **
3640: ** If F is the name of an sqlite database file, journal file, or WAL file
3641: ** that was passed by the SQLite core into the VFS, or if F is a database
3642: ** filename obtained from [sqlite3_db_filename()], then
3643: ** sqlite3_filename_wal(F) returns the name of the corresponding
3644: ** WAL file.
3645: **
3646: ** In all of the above, if F is not the name of a database, journal or WAL
3647: ** filename passed into the VFS from the SQLite core and F is not the
3648: ** return value from [sqlite3_db_filename()], then the result is
3649: ** undefined and is likely a memory access violation.
3650: */
3651: SQLITE_API const char *sqlite3_filename_database(const char*);
3652: SQLITE_API const char *sqlite3_filename_journal(const char*);
3653: SQLITE_API const char *sqlite3_filename_wal(const char*);
3654:
3655: /*
3656: ** CAPI3REF: Database File Corresponding To A Journal
3657: **
3658: ** ^If X is the name of a rollback or WAL-mode journal file that is
3659: ** passed into the xOpen method of [sqlite3_vfs], then
3660: ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3661: ** object that represents the main database file.
3662: **
3663: ** This routine is intended for use in custom [VFS] implementations
3664: ** only. It is not a general-purpose interface.
3665: ** The argument sqlite3_file_object(X) must be a filename pointer that
3666: ** has been passed into [sqlite3_vfs].xOpen method where the
3667: ** flags parameter to xOpen contains one of the bits
3668: ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3669: ** of this routine results in undefined and probably undesirable
3670: ** behavior.
3671: */
3672: SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3673:
3674: /*
3675: ** CAPI3REF: Create and Destroy VFS Filenames
3676: **
3677: ** These interfces are provided for use by [VFS shim] implementations and
3678: ** are not useful outside of that context.
3679: **
3680: ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3681: ** database filename D with corresponding journal file J and WAL file W and
3682: ** with N URI parameters key/values pairs in the array P. The result from
3683: ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3684: ** is safe to pass to routines like:
3685: ** <ul>
3686: ** <li> [sqlite3_uri_parameter()],
3687: ** <li> [sqlite3_uri_boolean()],
3688: ** <li> [sqlite3_uri_int64()],
3689: ** <li> [sqlite3_uri_key()],
3690: ** <li> [sqlite3_filename_database()],
3691: ** <li> [sqlite3_filename_journal()], or
3692: ** <li> [sqlite3_filename_wal()].
3693: ** </ul>
3694: ** If a memory allocation error occurs, sqlite3_create_filename() might
3695: ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3696: ** must be released by a corresponding call to sqlite3_free_filename(Y).
3697: **
3698: ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3699: ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3700: ** to a key and value for a query parameter. The P parameter may be a NULL
3701: ** pointer if N is zero. None of the 2*N pointers in the P array may be
3702: ** NULL pointers and key pointers should not be empty strings.
3703: ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3704: ** be NULL pointers, though they can be empty strings.
3705: **
3706: ** The sqlite3_free_filename(Y) routine releases a memory allocation
3707: ** previously obtained from sqlite3_create_filename(). Invoking
3708: ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3709: **
3710: ** If the Y parameter to sqlite3_free_filename(Y) is anything other
3711: ** than a NULL pointer or a pointer previously acquired from
3712: ** sqlite3_create_filename(), then bad things such as heap
1.6 ! misho 3713: ** corruption or segfaults may occur. The value Y should not be
1.5 misho 3714: ** used again after sqlite3_free_filename(Y) has been called. This means
3715: ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3716: ** then the corresponding [sqlite3_module.xClose() method should also be
3717: ** invoked prior to calling sqlite3_free_filename(Y).
3718: */
3719: SQLITE_API char *sqlite3_create_filename(
3720: const char *zDatabase,
3721: const char *zJournal,
3722: const char *zWal,
3723: int nParam,
3724: const char **azParam
3725: );
3726: SQLITE_API void sqlite3_free_filename(char*);
1.2 misho 3727:
3728: /*
3729: ** CAPI3REF: Error Codes And Messages
1.4 misho 3730: ** METHOD: sqlite3
1.2 misho 3731: **
1.5 misho 3732: ** ^If the most recent sqlite3_* API call associated with
1.4 misho 3733: ** [database connection] D failed, then the sqlite3_errcode(D) interface
3734: ** returns the numeric [result code] or [extended result code] for that
3735: ** API call.
3736: ** ^The sqlite3_extended_errcode()
1.5 misho 3737: ** interface is the same except that it always returns the
1.2 misho 3738: ** [extended result code] even when extended result codes are
3739: ** disabled.
3740: **
1.5 misho 3741: ** The values returned by sqlite3_errcode() and/or
3742: ** sqlite3_extended_errcode() might change with each API call.
3743: ** Except, there are some interfaces that are guaranteed to never
3744: ** change the value of the error code. The error-code preserving
3745: ** interfaces are:
3746: **
3747: ** <ul>
3748: ** <li> sqlite3_errcode()
3749: ** <li> sqlite3_extended_errcode()
3750: ** <li> sqlite3_errmsg()
3751: ** <li> sqlite3_errmsg16()
3752: ** </ul>
3753: **
1.2 misho 3754: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3755: ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3756: ** ^(Memory to hold the error message string is managed internally.
3757: ** The application does not need to worry about freeing the result.
3758: ** However, the error string might be overwritten or deallocated by
3759: ** subsequent calls to other SQLite interface functions.)^
3760: **
1.3 misho 3761: ** ^The sqlite3_errstr() interface returns the English-language text
3762: ** that describes the [result code], as UTF-8.
3763: ** ^(Memory to hold the error message string is managed internally
3764: ** and must not be freed by the application)^.
3765: **
1.2 misho 3766: ** When the serialized [threading mode] is in use, it might be the
3767: ** case that a second error occurs on a separate thread in between
3768: ** the time of the first error and the call to these interfaces.
3769: ** When that happens, the second error will be reported since these
3770: ** interfaces always report the most recent result. To avoid
3771: ** this, each thread can obtain exclusive use of the [database connection] D
3772: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3773: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3774: ** all calls to the interfaces listed here are completed.
3775: **
3776: ** If an interface fails with SQLITE_MISUSE, that means the interface
3777: ** was invoked incorrectly by the application. In that case, the
3778: ** error code and message may or may not be set.
3779: */
3780: SQLITE_API int sqlite3_errcode(sqlite3 *db);
3781: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3782: SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3783: SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
1.3 misho 3784: SQLITE_API const char *sqlite3_errstr(int);
1.2 misho 3785:
3786: /*
1.4 misho 3787: ** CAPI3REF: Prepared Statement Object
1.2 misho 3788: ** KEYWORDS: {prepared statement} {prepared statements}
3789: **
1.4 misho 3790: ** An instance of this object represents a single SQL statement that
3791: ** has been compiled into binary form and is ready to be evaluated.
3792: **
3793: ** Think of each SQL statement as a separate computer program. The
1.5 misho 3794: ** original SQL text is source code. A prepared statement object
1.4 misho 3795: ** is the compiled object code. All SQL must be converted into a
3796: ** prepared statement before it can be run.
1.2 misho 3797: **
1.4 misho 3798: ** The life-cycle of a prepared statement object usually goes like this:
1.2 misho 3799: **
3800: ** <ol>
1.4 misho 3801: ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3802: ** <li> Bind values to [parameters] using the sqlite3_bind_*()
1.2 misho 3803: ** interfaces.
3804: ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
1.4 misho 3805: ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
1.2 misho 3806: ** to step 2. Do this zero or more times.
3807: ** <li> Destroy the object using [sqlite3_finalize()].
3808: ** </ol>
3809: */
3810: typedef struct sqlite3_stmt sqlite3_stmt;
3811:
3812: /*
3813: ** CAPI3REF: Run-time Limits
1.4 misho 3814: ** METHOD: sqlite3
1.2 misho 3815: **
3816: ** ^(This interface allows the size of various constructs to be limited
3817: ** on a connection by connection basis. The first parameter is the
3818: ** [database connection] whose limit is to be set or queried. The
3819: ** second parameter is one of the [limit categories] that define a
3820: ** class of constructs to be size limited. The third parameter is the
3821: ** new limit for that construct.)^
3822: **
3823: ** ^If the new limit is a negative number, the limit is unchanged.
1.5 misho 3824: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
1.2 misho 3825: ** [limits | hard upper bound]
3826: ** set at compile-time by a C preprocessor macro called
3827: ** [limits | SQLITE_MAX_<i>NAME</i>].
3828: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3829: ** ^Attempts to increase a limit above its hard upper bound are
3830: ** silently truncated to the hard upper bound.
3831: **
1.5 misho 3832: ** ^Regardless of whether or not the limit was changed, the
1.2 misho 3833: ** [sqlite3_limit()] interface returns the prior value of the limit.
3834: ** ^Hence, to find the current value of a limit without changing it,
3835: ** simply invoke this interface with the third parameter set to -1.
3836: **
3837: ** Run-time limits are intended for use in applications that manage
3838: ** both their own internal database and also databases that are controlled
3839: ** by untrusted external sources. An example application might be a
3840: ** web browser that has its own databases for storing history and
3841: ** separate databases controlled by JavaScript applications downloaded
3842: ** off the Internet. The internal databases can be given the
3843: ** large, default limits. Databases managed by external sources can
3844: ** be given much smaller limits designed to prevent a denial of service
3845: ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3846: ** interface to further control untrusted SQL. The size of the database
3847: ** created by an untrusted script can be contained using the
3848: ** [max_page_count] [PRAGMA].
3849: **
3850: ** New run-time limit categories may be added in future releases.
3851: */
3852: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3853:
3854: /*
3855: ** CAPI3REF: Run-Time Limit Categories
3856: ** KEYWORDS: {limit category} {*limit categories}
3857: **
3858: ** These constants define various performance limits
3859: ** that can be lowered at run-time using [sqlite3_limit()].
3860: ** The synopsis of the meanings of the various limits is shown below.
3861: ** Additional information is available at [limits | Limits in SQLite].
3862: **
3863: ** <dl>
3864: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3865: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3866: **
3867: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3868: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3869: **
3870: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3871: ** <dd>The maximum number of columns in a table definition or in the
3872: ** result set of a [SELECT] or the maximum number of columns in an index
3873: ** or in an ORDER BY or GROUP BY clause.</dd>)^
3874: **
3875: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3876: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3877: **
3878: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3879: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3880: **
3881: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3882: ** <dd>The maximum number of instructions in a virtual machine program
1.5 misho 3883: ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3884: ** the equivalent tries to allocate space for more than this many opcodes
3885: ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
1.2 misho 3886: **
3887: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3888: ** <dd>The maximum number of arguments on a function.</dd>)^
3889: **
3890: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3891: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3892: **
3893: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3894: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3895: ** <dd>The maximum length of the pattern argument to the [LIKE] or
3896: ** [GLOB] operators.</dd>)^
3897: **
3898: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3899: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3900: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3901: **
3902: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3903: ** <dd>The maximum depth of recursion for triggers.</dd>)^
1.4 misho 3904: **
3905: ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3906: ** <dd>The maximum number of auxiliary worker threads that a single
3907: ** [prepared statement] may start.</dd>)^
1.2 misho 3908: ** </dl>
3909: */
3910: #define SQLITE_LIMIT_LENGTH 0
3911: #define SQLITE_LIMIT_SQL_LENGTH 1
3912: #define SQLITE_LIMIT_COLUMN 2
3913: #define SQLITE_LIMIT_EXPR_DEPTH 3
3914: #define SQLITE_LIMIT_COMPOUND_SELECT 4
3915: #define SQLITE_LIMIT_VDBE_OP 5
3916: #define SQLITE_LIMIT_FUNCTION_ARG 6
3917: #define SQLITE_LIMIT_ATTACHED 7
3918: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3919: #define SQLITE_LIMIT_VARIABLE_NUMBER 9
3920: #define SQLITE_LIMIT_TRIGGER_DEPTH 10
1.4 misho 3921: #define SQLITE_LIMIT_WORKER_THREADS 11
1.2 misho 3922:
3923: /*
1.5 misho 3924: ** CAPI3REF: Prepare Flags
3925: **
3926: ** These constants define various flags that can be passed into
3927: ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3928: ** [sqlite3_prepare16_v3()] interfaces.
3929: **
3930: ** New flags may be added in future releases of SQLite.
3931: **
3932: ** <dl>
3933: ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3934: ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3935: ** that the prepared statement will be retained for a long time and
3936: ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3937: ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3938: ** be used just once or at most a few times and then destroyed using
3939: ** [sqlite3_finalize()] relatively soon. The current implementation acts
3940: ** on this hint by avoiding the use of [lookaside memory] so as not to
3941: ** deplete the limited store of lookaside memory. Future versions of
3942: ** SQLite may act on this hint differently.
3943: **
3944: ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
3945: ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
3946: ** to be required for any prepared statement that wanted to use the
3947: ** [sqlite3_normalized_sql()] interface. However, the
3948: ** [sqlite3_normalized_sql()] interface is now available to all
3949: ** prepared statements, regardless of whether or not they use this
3950: ** flag.
3951: **
3952: ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
3953: ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
3954: ** to return an error (error code SQLITE_ERROR) if the statement uses
3955: ** any virtual tables.
3956: ** </dl>
3957: */
3958: #define SQLITE_PREPARE_PERSISTENT 0x01
3959: #define SQLITE_PREPARE_NORMALIZE 0x02
3960: #define SQLITE_PREPARE_NO_VTAB 0x04
3961:
3962: /*
1.2 misho 3963: ** CAPI3REF: Compiling An SQL Statement
3964: ** KEYWORDS: {SQL statement compiler}
1.4 misho 3965: ** METHOD: sqlite3
3966: ** CONSTRUCTOR: sqlite3_stmt
1.2 misho 3967: **
1.5 misho 3968: ** To execute an SQL statement, it must first be compiled into a byte-code
3969: ** program using one of these routines. Or, in other words, these routines
3970: ** are constructors for the [prepared statement] object.
3971: **
3972: ** The preferred routine to use is [sqlite3_prepare_v2()]. The
3973: ** [sqlite3_prepare()] interface is legacy and should be avoided.
3974: ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3975: ** for special purposes.
3976: **
3977: ** The use of the UTF-8 interfaces is preferred, as SQLite currently
3978: ** does all parsing using UTF-8. The UTF-16 interfaces are provided
3979: ** as a convenience. The UTF-16 interfaces work by converting the
3980: ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
1.2 misho 3981: **
3982: ** The first argument, "db", is a [database connection] obtained from a
3983: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3984: ** [sqlite3_open16()]. The database connection must not have been closed.
3985: **
3986: ** The second argument, "zSql", is the statement to be compiled, encoded
1.5 misho 3987: ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3988: ** and sqlite3_prepare_v3()
3989: ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3990: ** and sqlite3_prepare16_v3() use UTF-16.
1.2 misho 3991: **
1.4 misho 3992: ** ^If the nByte argument is negative, then zSql is read up to the
3993: ** first zero terminator. ^If nByte is positive, then it is the
3994: ** number of bytes read from zSql. ^If nByte is zero, then no prepared
3995: ** statement is generated.
3996: ** If the caller knows that the supplied string is nul-terminated, then
3997: ** there is a small performance advantage to passing an nByte parameter that
3998: ** is the number of bytes in the input string <i>including</i>
3999: ** the nul-terminator.
1.2 misho 4000: **
4001: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4002: ** past the end of the first SQL statement in zSql. These routines only
4003: ** compile the first statement in zSql, so *pzTail is left pointing to
4004: ** what remains uncompiled.
4005: **
4006: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4007: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4008: ** to NULL. ^If the input text contains no SQL (if the input is an empty
4009: ** string or a comment) then *ppStmt is set to NULL.
4010: ** The calling procedure is responsible for deleting the compiled
4011: ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4012: ** ppStmt may not be NULL.
4013: **
4014: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4015: ** otherwise an [error code] is returned.
4016: **
1.5 misho 4017: ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4018: ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4019: ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4020: ** are retained for backwards compatibility, but their use is discouraged.
4021: ** ^In the "vX" interfaces, the prepared statement
1.2 misho 4022: ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4023: ** original SQL text. This causes the [sqlite3_step()] interface to
4024: ** behave differently in three ways:
4025: **
4026: ** <ol>
4027: ** <li>
4028: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4029: ** always used to do, [sqlite3_step()] will automatically recompile the SQL
1.4 misho 4030: ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4031: ** retries will occur before sqlite3_step() gives up and returns an error.
1.2 misho 4032: ** </li>
4033: **
4034: ** <li>
4035: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4036: ** [error codes] or [extended error codes]. ^The legacy behavior was that
4037: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4038: ** and the application would have to make a second call to [sqlite3_reset()]
4039: ** in order to find the underlying cause of the problem. With the "v2" prepare
4040: ** interfaces, the underlying reason for the error is returned immediately.
4041: ** </li>
4042: **
4043: ** <li>
1.5 misho 4044: ** ^If the specific value bound to a [parameter | host parameter] in the
1.2 misho 4045: ** WHERE clause might influence the choice of query plan for a statement,
1.5 misho 4046: ** then the statement will be automatically recompiled, as if there had been
4047: ** a schema change, on the first [sqlite3_step()] call following any change
4048: ** to the [sqlite3_bind_text | bindings] of that [parameter].
4049: ** ^The specific value of a WHERE-clause [parameter] might influence the
1.2 misho 4050: ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4051: ** or [GLOB] operator or if the parameter is compared to an indexed column
1.5 misho 4052: ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
1.2 misho 4053: ** </li>
4054: ** </ol>
1.5 misho 4055: **
4056: ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4057: ** the extra prepFlags parameter, which is a bit array consisting of zero or
4058: ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4059: ** sqlite3_prepare_v2() interface works exactly the same as
4060: ** sqlite3_prepare_v3() with a zero prepFlags parameter.
1.2 misho 4061: */
4062: SQLITE_API int sqlite3_prepare(
4063: sqlite3 *db, /* Database handle */
4064: const char *zSql, /* SQL statement, UTF-8 encoded */
4065: int nByte, /* Maximum length of zSql in bytes. */
4066: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4067: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4068: );
4069: SQLITE_API int sqlite3_prepare_v2(
4070: sqlite3 *db, /* Database handle */
4071: const char *zSql, /* SQL statement, UTF-8 encoded */
4072: int nByte, /* Maximum length of zSql in bytes. */
4073: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4074: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4075: );
1.5 misho 4076: SQLITE_API int sqlite3_prepare_v3(
4077: sqlite3 *db, /* Database handle */
4078: const char *zSql, /* SQL statement, UTF-8 encoded */
4079: int nByte, /* Maximum length of zSql in bytes. */
4080: unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4081: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4082: const char **pzTail /* OUT: Pointer to unused portion of zSql */
4083: );
1.2 misho 4084: SQLITE_API int sqlite3_prepare16(
4085: sqlite3 *db, /* Database handle */
4086: const void *zSql, /* SQL statement, UTF-16 encoded */
4087: int nByte, /* Maximum length of zSql in bytes. */
4088: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4089: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4090: );
4091: SQLITE_API int sqlite3_prepare16_v2(
4092: sqlite3 *db, /* Database handle */
4093: const void *zSql, /* SQL statement, UTF-16 encoded */
4094: int nByte, /* Maximum length of zSql in bytes. */
4095: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4096: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4097: );
1.5 misho 4098: SQLITE_API int sqlite3_prepare16_v3(
4099: sqlite3 *db, /* Database handle */
4100: const void *zSql, /* SQL statement, UTF-16 encoded */
4101: int nByte, /* Maximum length of zSql in bytes. */
4102: unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4103: sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4104: const void **pzTail /* OUT: Pointer to unused portion of zSql */
4105: );
1.2 misho 4106:
4107: /*
4108: ** CAPI3REF: Retrieving Statement SQL
1.4 misho 4109: ** METHOD: sqlite3_stmt
1.2 misho 4110: **
1.4 misho 4111: ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4112: ** SQL text used to create [prepared statement] P if P was
1.5 misho 4113: ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4114: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
1.4 misho 4115: ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4116: ** string containing the SQL text of prepared statement P with
4117: ** [bound parameters] expanded.
1.5 misho 4118: ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4119: ** string containing the normalized SQL text of prepared statement P. The
4120: ** semantics used to normalize a SQL statement are unspecified and subject
4121: ** to change. At a minimum, literal values will be replaced with suitable
4122: ** placeholders.
1.4 misho 4123: **
4124: ** ^(For example, if a prepared statement is created using the SQL
4125: ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4126: ** and parameter :xyz is unbound, then sqlite3_sql() will return
4127: ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4128: ** will return "SELECT 2345,NULL".)^
4129: **
4130: ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4131: ** is available to hold the result, or if the result would exceed the
4132: ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4133: **
4134: ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4135: ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4136: ** option causes sqlite3_expanded_sql() to always return NULL.
4137: **
1.5 misho 4138: ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4139: ** are managed by SQLite and are automatically freed when the prepared
4140: ** statement is finalized.
1.4 misho 4141: ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4142: ** is obtained from [sqlite3_malloc()] and must be free by the application
4143: ** by passing it to [sqlite3_free()].
1.2 misho 4144: */
4145: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
1.4 misho 4146: SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
1.5 misho 4147: SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
1.2 misho 4148:
4149: /*
4150: ** CAPI3REF: Determine If An SQL Statement Writes The Database
1.4 misho 4151: ** METHOD: sqlite3_stmt
1.2 misho 4152: **
4153: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4154: ** and only if the [prepared statement] X makes no direct changes to
4155: ** the content of the database file.
4156: **
4157: ** Note that [application-defined SQL functions] or
1.5 misho 4158: ** [virtual tables] might change the database indirectly as a side effect.
4159: ** ^(For example, if an application defines a function "eval()" that
1.2 misho 4160: ** calls [sqlite3_exec()], then the following SQL statement would
4161: ** change the database file through side-effects:
4162: **
4163: ** <blockquote><pre>
4164: ** SELECT eval('DELETE FROM t1') FROM t2;
4165: ** </pre></blockquote>
4166: **
4167: ** But because the [SELECT] statement does not change the database file
4168: ** directly, sqlite3_stmt_readonly() would still return true.)^
4169: **
4170: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4171: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4172: ** since the statements themselves do not actually modify the database but
1.5 misho 4173: ** rather they control the timing of when other statements modify the
1.2 misho 4174: ** database. ^The [ATTACH] and [DETACH] statements also cause
4175: ** sqlite3_stmt_readonly() to return true since, while those statements
1.5 misho 4176: ** change the configuration of a database connection, they do not make
1.2 misho 4177: ** changes to the content of the database files on disk.
1.5 misho 4178: ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4179: ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4180: ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4181: ** sqlite3_stmt_readonly() returns false for those commands.
1.2 misho 4182: */
4183: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4184:
4185: /*
1.5 misho 4186: ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4187: ** METHOD: sqlite3_stmt
4188: **
4189: ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4190: ** prepared statement S is an EXPLAIN statement, or 2 if the
4191: ** statement S is an EXPLAIN QUERY PLAN.
4192: ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4193: ** an ordinary statement or a NULL pointer.
4194: */
4195: SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4196:
4197: /*
1.2 misho 4198: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
1.4 misho 4199: ** METHOD: sqlite3_stmt
1.2 misho 4200: **
4201: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
1.5 misho 4202: ** [prepared statement] S has been stepped at least once using
1.4 misho 4203: ** [sqlite3_step(S)] but has neither run to completion (returned
4204: ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
1.2 misho 4205: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
1.5 misho 4206: ** interface returns false if S is a NULL pointer. If S is not a
1.2 misho 4207: ** NULL pointer and is not a pointer to a valid [prepared statement]
4208: ** object, then the behavior is undefined and probably undesirable.
4209: **
4210: ** This interface can be used in combination [sqlite3_next_stmt()]
1.5 misho 4211: ** to locate all prepared statements associated with a database
1.2 misho 4212: ** connection that are in need of being reset. This can be used,
1.5 misho 4213: ** for example, in diagnostic routines to search for prepared
1.2 misho 4214: ** statements that are holding a transaction open.
4215: */
4216: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4217:
4218: /*
4219: ** CAPI3REF: Dynamically Typed Value Object
4220: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4221: **
4222: ** SQLite uses the sqlite3_value object to represent all values
4223: ** that can be stored in a database table. SQLite uses dynamic typing
4224: ** for the values it stores. ^Values stored in sqlite3_value objects
4225: ** can be integers, floating point values, strings, BLOBs, or NULL.
4226: **
4227: ** An sqlite3_value object may be either "protected" or "unprotected".
4228: ** Some interfaces require a protected sqlite3_value. Other interfaces
4229: ** will accept either a protected or an unprotected sqlite3_value.
4230: ** Every interface that accepts sqlite3_value arguments specifies
1.4 misho 4231: ** whether or not it requires a protected sqlite3_value. The
1.5 misho 4232: ** [sqlite3_value_dup()] interface can be used to construct a new
1.4 misho 4233: ** protected sqlite3_value from an unprotected sqlite3_value.
1.2 misho 4234: **
4235: ** The terms "protected" and "unprotected" refer to whether or not
4236: ** a mutex is held. An internal mutex is held for a protected
4237: ** sqlite3_value object but no mutex is held for an unprotected
4238: ** sqlite3_value object. If SQLite is compiled to be single-threaded
4239: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
1.5 misho 4240: ** or if SQLite is run in one of reduced mutex modes
1.2 misho 4241: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4242: ** then there is no distinction between protected and unprotected
4243: ** sqlite3_value objects and they can be used interchangeably. However,
4244: ** for maximum code portability it is recommended that applications
4245: ** still make the distinction between protected and unprotected
4246: ** sqlite3_value objects even when not strictly required.
4247: **
4248: ** ^The sqlite3_value objects that are passed as parameters into the
4249: ** implementation of [application-defined SQL functions] are protected.
4250: ** ^The sqlite3_value object returned by
4251: ** [sqlite3_column_value()] is unprotected.
1.5 misho 4252: ** Unprotected sqlite3_value objects may only be used as arguments
4253: ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4254: ** [sqlite3_value_dup()].
1.2 misho 4255: ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4256: ** interfaces require protected sqlite3_value objects.
4257: */
1.5 misho 4258: typedef struct sqlite3_value sqlite3_value;
1.2 misho 4259:
4260: /*
4261: ** CAPI3REF: SQL Function Context Object
4262: **
4263: ** The context in which an SQL function executes is stored in an
4264: ** sqlite3_context object. ^A pointer to an sqlite3_context object
4265: ** is always first parameter to [application-defined SQL functions].
4266: ** The application-defined SQL function implementation will pass this
4267: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4268: ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4269: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4270: ** and/or [sqlite3_set_auxdata()].
4271: */
4272: typedef struct sqlite3_context sqlite3_context;
4273:
4274: /*
4275: ** CAPI3REF: Binding Values To Prepared Statements
4276: ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4277: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
1.4 misho 4278: ** METHOD: sqlite3_stmt
1.2 misho 4279: **
4280: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4281: ** literals may be replaced by a [parameter] that matches one of following
4282: ** templates:
4283: **
4284: ** <ul>
4285: ** <li> ?
4286: ** <li> ?NNN
4287: ** <li> :VVV
4288: ** <li> @VVV
4289: ** <li> $VVV
4290: ** </ul>
4291: **
4292: ** In the templates above, NNN represents an integer literal,
4293: ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4294: ** parameters (also called "host parameter names" or "SQL parameters")
4295: ** can be set using the sqlite3_bind_*() routines defined here.
4296: **
4297: ** ^The first argument to the sqlite3_bind_*() routines is always
4298: ** a pointer to the [sqlite3_stmt] object returned from
4299: ** [sqlite3_prepare_v2()] or its variants.
4300: **
4301: ** ^The second argument is the index of the SQL parameter to be set.
4302: ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4303: ** SQL parameter is used more than once, second and subsequent
4304: ** occurrences have the same index as the first occurrence.
4305: ** ^The index for named parameters can be looked up using the
4306: ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4307: ** for "?NNN" parameters is the value of NNN.
4308: ** ^The NNN value must be between 1 and the [sqlite3_limit()]
1.5 misho 4309: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
1.2 misho 4310: **
4311: ** ^The third argument is the value to bind to the parameter.
1.4 misho 4312: ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4313: ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4314: ** is ignored and the end result is the same as sqlite3_bind_null().
1.5 misho 4315: ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4316: ** it should be a pointer to well-formed UTF8 text.
4317: ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4318: ** it should be a pointer to well-formed UTF16 text.
4319: ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4320: ** it should be a pointer to a well-formed unicode string that is
4321: ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4322: ** otherwise.
4323: **
4324: ** [[byte-order determination rules]] ^The byte-order of
4325: ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4326: ** found in first character, which is removed, or in the absence of a BOM
4327: ** the byte order is the native byte order of the host
4328: ** machine for sqlite3_bind_text16() or the byte order specified in
4329: ** the 6th parameter for sqlite3_bind_text64().)^
4330: ** ^If UTF16 input text contains invalid unicode
4331: ** characters, then SQLite might change those invalid characters
4332: ** into the unicode replacement character: U+FFFD.
1.2 misho 4333: **
4334: ** ^(In those routines that have a fourth argument, its value is the
4335: ** number of bytes in the parameter. To be clear: the value is the
4336: ** number of <u>bytes</u> in the value, not the number of characters.)^
1.3 misho 4337: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4338: ** is negative, then the length of the string is
1.2 misho 4339: ** the number of bytes up to the first zero terminator.
1.3 misho 4340: ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4341: ** the behavior is undefined.
1.2 misho 4342: ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
1.4 misho 4343: ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4344: ** that parameter must be the byte offset
1.2 misho 4345: ** where the NUL terminator would occur assuming the string were NUL
1.5 misho 4346: ** terminated. If any NUL characters occurs at byte offsets less than
1.2 misho 4347: ** the value of the fourth parameter then the resulting string value will
4348: ** contain embedded NULs. The result of expressions involving strings
4349: ** with embedded NULs is undefined.
4350: **
1.4 misho 4351: ** ^The fifth argument to the BLOB and string binding interfaces
4352: ** is a destructor used to dispose of the BLOB or
1.2 misho 4353: ** string after SQLite has finished with it. ^The destructor is called
1.5 misho 4354: ** to dispose of the BLOB or string even if the call to the bind API fails,
4355: ** except the destructor is not called if the third parameter is a NULL
4356: ** pointer or the fourth parameter is negative.
1.2 misho 4357: ** ^If the fifth argument is
4358: ** the special value [SQLITE_STATIC], then SQLite assumes that the
4359: ** information is in static, unmanaged space and does not need to be freed.
4360: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4361: ** SQLite makes its own private copy of the data immediately, before
4362: ** the sqlite3_bind_*() routine returns.
4363: **
1.4 misho 4364: ** ^The sixth argument to sqlite3_bind_text64() must be one of
4365: ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4366: ** to specify the encoding of the text in the third parameter. If
4367: ** the sixth argument to sqlite3_bind_text64() is not one of the
4368: ** allowed values shown above, or if the text encoding is different
4369: ** from the encoding specified by the sixth parameter, then the behavior
4370: ** is undefined.
4371: **
1.2 misho 4372: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4373: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4374: ** (just an integer to hold its size) while it is being processed.
4375: ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4376: ** content is later written using
4377: ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4378: ** ^A negative value for the zeroblob results in a zero-length BLOB.
4379: **
1.5 misho 4380: ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4381: ** [prepared statement] S to have an SQL value of NULL, but to also be
4382: ** associated with the pointer P of type T. ^D is either a NULL pointer or
4383: ** a pointer to a destructor function for P. ^SQLite will invoke the
4384: ** destructor D with a single argument of P when it is finished using
4385: ** P. The T parameter should be a static string, preferably a string
4386: ** literal. The sqlite3_bind_pointer() routine is part of the
4387: ** [pointer passing interface] added for SQLite 3.20.0.
4388: **
1.2 misho 4389: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4390: ** for the [prepared statement] or with a prepared statement for which
4391: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4392: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4393: ** routine is passed a [prepared statement] that has been finalized, the
4394: ** result is undefined and probably harmful.
4395: **
4396: ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4397: ** ^Unbound parameters are interpreted as NULL.
4398: **
4399: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4400: ** [error code] if anything goes wrong.
1.4 misho 4401: ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4402: ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4403: ** [SQLITE_MAX_LENGTH].
1.2 misho 4404: ** ^[SQLITE_RANGE] is returned if the parameter
4405: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4406: **
4407: ** See also: [sqlite3_bind_parameter_count()],
4408: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4409: */
4410: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
1.4 misho 4411: SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4412: void(*)(void*));
1.2 misho 4413: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4414: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4415: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4416: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
1.4 misho 4417: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
1.2 misho 4418: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
1.4 misho 4419: SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4420: void(*)(void*), unsigned char encoding);
1.2 misho 4421: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
1.5 misho 4422: SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
1.2 misho 4423: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
1.4 misho 4424: SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
1.2 misho 4425:
4426: /*
4427: ** CAPI3REF: Number Of SQL Parameters
1.4 misho 4428: ** METHOD: sqlite3_stmt
1.2 misho 4429: **
4430: ** ^This routine can be used to find the number of [SQL parameters]
4431: ** in a [prepared statement]. SQL parameters are tokens of the
4432: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4433: ** placeholders for values that are [sqlite3_bind_blob | bound]
4434: ** to the parameters at a later time.
4435: **
4436: ** ^(This routine actually returns the index of the largest (rightmost)
4437: ** parameter. For all forms except ?NNN, this will correspond to the
4438: ** number of unique parameters. If parameters of the ?NNN form are used,
4439: ** there may be gaps in the list.)^
4440: **
4441: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4442: ** [sqlite3_bind_parameter_name()], and
4443: ** [sqlite3_bind_parameter_index()].
4444: */
4445: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4446:
4447: /*
4448: ** CAPI3REF: Name Of A Host Parameter
1.4 misho 4449: ** METHOD: sqlite3_stmt
1.2 misho 4450: **
4451: ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4452: ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4453: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4454: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4455: ** respectively.
4456: ** In other words, the initial ":" or "$" or "@" or "?"
4457: ** is included as part of the name.)^
4458: ** ^Parameters of the form "?" without a following integer have no name
4459: ** and are referred to as "nameless" or "anonymous parameters".
4460: **
4461: ** ^The first host parameter has an index of 1, not 0.
4462: **
4463: ** ^If the value N is out of range or if the N-th parameter is
4464: ** nameless, then NULL is returned. ^The returned string is
4465: ** always in UTF-8 encoding even if the named parameter was
1.5 misho 4466: ** originally specified as UTF-16 in [sqlite3_prepare16()],
4467: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
1.2 misho 4468: **
4469: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4470: ** [sqlite3_bind_parameter_count()], and
4471: ** [sqlite3_bind_parameter_index()].
4472: */
4473: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4474:
4475: /*
4476: ** CAPI3REF: Index Of A Parameter With A Given Name
1.4 misho 4477: ** METHOD: sqlite3_stmt
1.2 misho 4478: **
4479: ** ^Return the index of an SQL parameter given its name. ^The
4480: ** index value returned is suitable for use as the second
4481: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4482: ** is returned if no matching parameter is found. ^The parameter
4483: ** name must be given in UTF-8 even if the original statement
1.5 misho 4484: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4485: ** [sqlite3_prepare16_v3()].
1.2 misho 4486: **
4487: ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4488: ** [sqlite3_bind_parameter_count()], and
1.4 misho 4489: ** [sqlite3_bind_parameter_name()].
1.2 misho 4490: */
4491: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4492:
4493: /*
4494: ** CAPI3REF: Reset All Bindings On A Prepared Statement
1.4 misho 4495: ** METHOD: sqlite3_stmt
1.2 misho 4496: **
4497: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4498: ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4499: ** ^Use this routine to reset all host parameters to NULL.
4500: */
4501: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4502:
4503: /*
4504: ** CAPI3REF: Number Of Columns In A Result Set
1.4 misho 4505: ** METHOD: sqlite3_stmt
1.2 misho 4506: **
4507: ** ^Return the number of columns in the result set returned by the
1.5 misho 4508: ** [prepared statement]. ^If this routine returns 0, that means the
4509: ** [prepared statement] returns no data (for example an [UPDATE]).
4510: ** ^However, just because this routine returns a positive number does not
4511: ** mean that one or more rows of data will be returned. ^A SELECT statement
4512: ** will always have a positive sqlite3_column_count() but depending on the
4513: ** WHERE clause constraints and the table content, it might return no rows.
1.2 misho 4514: **
4515: ** See also: [sqlite3_data_count()]
4516: */
4517: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4518:
4519: /*
4520: ** CAPI3REF: Column Names In A Result Set
1.4 misho 4521: ** METHOD: sqlite3_stmt
1.2 misho 4522: **
4523: ** ^These routines return the name assigned to a particular column
4524: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4525: ** interface returns a pointer to a zero-terminated UTF-8 string
4526: ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4527: ** UTF-16 string. ^The first parameter is the [prepared statement]
4528: ** that implements the [SELECT] statement. ^The second parameter is the
4529: ** column number. ^The leftmost column is number 0.
4530: **
4531: ** ^The returned string pointer is valid until either the [prepared statement]
4532: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4533: ** reprepared by the first call to [sqlite3_step()] for a particular run
4534: ** or until the next call to
4535: ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4536: **
4537: ** ^If sqlite3_malloc() fails during the processing of either routine
4538: ** (for example during a conversion from UTF-8 to UTF-16) then a
4539: ** NULL pointer is returned.
4540: **
4541: ** ^The name of a result column is the value of the "AS" clause for
4542: ** that column, if there is an AS clause. If there is no AS clause
4543: ** then the name of the column is unspecified and may change from
4544: ** one release of SQLite to the next.
4545: */
4546: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4547: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4548:
4549: /*
4550: ** CAPI3REF: Source Of Data In A Query Result
1.4 misho 4551: ** METHOD: sqlite3_stmt
1.2 misho 4552: **
4553: ** ^These routines provide a means to determine the database, table, and
4554: ** table column that is the origin of a particular result column in
4555: ** [SELECT] statement.
4556: ** ^The name of the database or table or column can be returned as
4557: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4558: ** the database name, the _table_ routines return the table name, and
4559: ** the origin_ routines return the column name.
4560: ** ^The returned string is valid until the [prepared statement] is destroyed
4561: ** using [sqlite3_finalize()] or until the statement is automatically
4562: ** reprepared by the first call to [sqlite3_step()] for a particular run
4563: ** or until the same information is requested
4564: ** again in a different encoding.
4565: **
4566: ** ^The names returned are the original un-aliased names of the
4567: ** database, table, and column.
4568: **
4569: ** ^The first argument to these interfaces is a [prepared statement].
4570: ** ^These functions return information about the Nth result column returned by
4571: ** the statement, where N is the second function argument.
4572: ** ^The left-most column is column 0 for these routines.
4573: **
4574: ** ^If the Nth column returned by the statement is an expression or
4575: ** subquery and is not a column value, then all of these functions return
1.5 misho 4576: ** NULL. ^These routines might also return NULL if a memory allocation error
1.2 misho 4577: ** occurs. ^Otherwise, they return the name of the attached database, table,
4578: ** or column that query result column was extracted from.
4579: **
4580: ** ^As with all other SQLite APIs, those whose names end with "16" return
4581: ** UTF-16 encoded strings and the other functions return UTF-8.
4582: **
4583: ** ^These APIs are only available if the library was compiled with the
4584: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4585: **
4586: ** If two or more threads call one or more
4587: ** [sqlite3_column_database_name | column metadata interfaces]
4588: ** for the same [prepared statement] and result column
4589: ** at the same time then the results are undefined.
4590: */
4591: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4592: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4593: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4594: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4595: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4596: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4597:
4598: /*
4599: ** CAPI3REF: Declared Datatype Of A Query Result
1.4 misho 4600: ** METHOD: sqlite3_stmt
1.2 misho 4601: **
4602: ** ^(The first parameter is a [prepared statement].
4603: ** If this statement is a [SELECT] statement and the Nth column of the
4604: ** returned result set of that [SELECT] is a table column (not an
4605: ** expression or subquery) then the declared type of the table
4606: ** column is returned.)^ ^If the Nth column of the result set is an
4607: ** expression or subquery, then a NULL pointer is returned.
4608: ** ^The returned string is always UTF-8 encoded.
4609: **
4610: ** ^(For example, given the database schema:
4611: **
4612: ** CREATE TABLE t1(c1 VARIANT);
4613: **
4614: ** and the following statement to be compiled:
4615: **
4616: ** SELECT c1 + 1, c1 FROM t1;
4617: **
4618: ** this routine would return the string "VARIANT" for the second result
4619: ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4620: **
4621: ** ^SQLite uses dynamic run-time typing. ^So just because a column
4622: ** is declared to contain a particular type does not mean that the
4623: ** data stored in that column is of the declared type. SQLite is
4624: ** strongly typed, but the typing is dynamic not static. ^Type
4625: ** is associated with individual values, not with the containers
4626: ** used to hold those values.
4627: */
4628: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4629: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4630:
4631: /*
4632: ** CAPI3REF: Evaluate An SQL Statement
1.4 misho 4633: ** METHOD: sqlite3_stmt
1.2 misho 4634: **
1.5 misho 4635: ** After a [prepared statement] has been prepared using any of
4636: ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4637: ** or [sqlite3_prepare16_v3()] or one of the legacy
1.2 misho 4638: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4639: ** must be called one or more times to evaluate the statement.
4640: **
4641: ** The details of the behavior of the sqlite3_step() interface depend
1.5 misho 4642: ** on whether the statement was prepared using the newer "vX" interfaces
4643: ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4644: ** [sqlite3_prepare16_v2()] or the older legacy
4645: ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4646: ** new "vX" interface is recommended for new applications but the legacy
1.2 misho 4647: ** interface will continue to be supported.
4648: **
4649: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4650: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4651: ** ^With the "v2" interface, any of the other [result codes] or
4652: ** [extended result codes] might be returned as well.
4653: **
4654: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4655: ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4656: ** or occurs outside of an explicit transaction, then you can retry the
4657: ** statement. If the statement is not a [COMMIT] and occurs within an
4658: ** explicit transaction then you should rollback the transaction before
4659: ** continuing.
4660: **
4661: ** ^[SQLITE_DONE] means that the statement has finished executing
4662: ** successfully. sqlite3_step() should not be called again on this virtual
4663: ** machine without first calling [sqlite3_reset()] to reset the virtual
4664: ** machine back to its initial state.
4665: **
4666: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4667: ** is returned each time a new row of data is ready for processing by the
4668: ** caller. The values may be accessed using the [column access functions].
4669: ** sqlite3_step() is called again to retrieve the next row of data.
4670: **
4671: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4672: ** violation) has occurred. sqlite3_step() should not be called again on
4673: ** the VM. More information may be found by calling [sqlite3_errmsg()].
4674: ** ^With the legacy interface, a more specific error code (for example,
4675: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4676: ** can be obtained by calling [sqlite3_reset()] on the
4677: ** [prepared statement]. ^In the "v2" interface,
4678: ** the more specific error code is returned directly by sqlite3_step().
4679: **
4680: ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4681: ** Perhaps it was called on a [prepared statement] that has
4682: ** already been [sqlite3_finalize | finalized] or on one that had
4683: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4684: ** be the case that the same database connection is being used by two or
4685: ** more threads at the same moment in time.
4686: **
4687: ** For all versions of SQLite up to and including 3.6.23.1, a call to
4688: ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4689: ** other than [SQLITE_ROW] before any subsequent invocation of
1.5 misho 4690: ** sqlite3_step(). Failure to reset the prepared statement using
1.2 misho 4691: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
1.5 misho 4692: ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4693: ** sqlite3_step() began
1.2 misho 4694: ** calling [sqlite3_reset()] automatically in this circumstance rather
4695: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4696: ** break because any application that ever receives an SQLITE_MISUSE error
4697: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4698: ** can be used to restore the legacy behavior.
4699: **
4700: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4701: ** API always returns a generic error code, [SQLITE_ERROR], following any
4702: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4703: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4704: ** specific [error codes] that better describes the error.
4705: ** We admit that this is a goofy design. The problem has been fixed
4706: ** with the "v2" interface. If you prepare all of your SQL statements
1.5 misho 4707: ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4708: ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
1.2 misho 4709: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4710: ** then the more specific [error codes] are returned directly
1.5 misho 4711: ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
1.2 misho 4712: */
4713: SQLITE_API int sqlite3_step(sqlite3_stmt*);
4714:
4715: /*
4716: ** CAPI3REF: Number of columns in a result set
1.4 misho 4717: ** METHOD: sqlite3_stmt
1.2 misho 4718: **
4719: ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4720: ** current row of the result set of [prepared statement] P.
4721: ** ^If prepared statement P does not have results ready to return
1.5 misho 4722: ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
1.2 misho 4723: ** interfaces) then sqlite3_data_count(P) returns 0.
4724: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4725: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4726: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4727: ** will return non-zero if previous call to [sqlite3_step](P) returned
4728: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4729: ** where it always returns zero since each step of that multi-step
4730: ** pragma returns 0 columns of data.
4731: **
4732: ** See also: [sqlite3_column_count()]
4733: */
4734: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4735:
4736: /*
4737: ** CAPI3REF: Fundamental Datatypes
4738: ** KEYWORDS: SQLITE_TEXT
4739: **
4740: ** ^(Every value in SQLite has one of five fundamental datatypes:
4741: **
4742: ** <ul>
4743: ** <li> 64-bit signed integer
4744: ** <li> 64-bit IEEE floating point number
4745: ** <li> string
4746: ** <li> BLOB
4747: ** <li> NULL
4748: ** </ul>)^
4749: **
4750: ** These constants are codes for each of those types.
4751: **
4752: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4753: ** for a completely different meaning. Software that links against both
4754: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4755: ** SQLITE_TEXT.
4756: */
4757: #define SQLITE_INTEGER 1
4758: #define SQLITE_FLOAT 2
4759: #define SQLITE_BLOB 4
4760: #define SQLITE_NULL 5
4761: #ifdef SQLITE_TEXT
4762: # undef SQLITE_TEXT
4763: #else
4764: # define SQLITE_TEXT 3
4765: #endif
4766: #define SQLITE3_TEXT 3
4767:
4768: /*
4769: ** CAPI3REF: Result Values From A Query
4770: ** KEYWORDS: {column access functions}
1.4 misho 4771: ** METHOD: sqlite3_stmt
1.2 misho 4772: **
1.5 misho 4773: ** <b>Summary:</b>
4774: ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4775: ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
4776: ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
4777: ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
4778: ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
4779: ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
4780: ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
4781: ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
4782: ** [sqlite3_value|unprotected sqlite3_value] object.
4783: ** <tr><td> <td> <td>
4784: ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
4785: ** or a UTF-8 TEXT result in bytes
4786: ** <tr><td><b>sqlite3_column_bytes16 </b>
4787: ** <td>→ <td>Size of UTF-16
4788: ** TEXT in bytes
4789: ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
4790: ** datatype of the result
4791: ** </table></blockquote>
4792: **
4793: ** <b>Details:</b>
4794: **
1.2 misho 4795: ** ^These routines return information about a single column of the current
4796: ** result row of a query. ^In every case the first argument is a pointer
4797: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4798: ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4799: ** and the second argument is the index of the column for which information
4800: ** should be returned. ^The leftmost column of the result set has the index 0.
4801: ** ^The number of columns in the result can be determined using
4802: ** [sqlite3_column_count()].
4803: **
4804: ** If the SQL statement does not currently point to a valid row, or if the
4805: ** column index is out of range, the result is undefined.
4806: ** These routines may only be called when the most recent call to
4807: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4808: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4809: ** If any of these routines are called after [sqlite3_reset()] or
4810: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4811: ** something other than [SQLITE_ROW], the results are undefined.
4812: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4813: ** are called from a different thread while any of these routines
4814: ** are pending, then the results are undefined.
4815: **
1.5 misho 4816: ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4817: ** each return the value of a result column in a specific data format. If
4818: ** the result column is not initially in the requested format (for example,
4819: ** if the query returns an integer but the sqlite3_column_text() interface
4820: ** is used to extract the value) then an automatic type conversion is performed.
4821: **
1.2 misho 4822: ** ^The sqlite3_column_type() routine returns the
4823: ** [SQLITE_INTEGER | datatype code] for the initial data type
4824: ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
1.5 misho 4825: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4826: ** The return value of sqlite3_column_type() can be used to decide which
4827: ** of the first six interface should be used to extract the column value.
4828: ** The value returned by sqlite3_column_type() is only meaningful if no
4829: ** automatic type conversions have occurred for the value in question.
4830: ** After a type conversion, the result of calling sqlite3_column_type()
4831: ** is undefined, though harmless. Future
1.2 misho 4832: ** versions of SQLite may change the behavior of sqlite3_column_type()
4833: ** following a type conversion.
4834: **
1.5 misho 4835: ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4836: ** or sqlite3_column_bytes16() interfaces can be used to determine the size
4837: ** of that BLOB or string.
4838: **
1.2 misho 4839: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4840: ** routine returns the number of bytes in that BLOB or string.
4841: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4842: ** the string to UTF-8 and then returns the number of bytes.
4843: ** ^If the result is a numeric value then sqlite3_column_bytes() uses
4844: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4845: ** the number of bytes in that string.
4846: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4847: **
4848: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4849: ** routine returns the number of bytes in that BLOB or string.
4850: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4851: ** the string to UTF-16 and then returns the number of bytes.
4852: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4853: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4854: ** the number of bytes in that string.
4855: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4856: **
1.5 misho 4857: ** ^The values returned by [sqlite3_column_bytes()] and
1.2 misho 4858: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4859: ** of the string. ^For clarity: the values returned by
4860: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4861: ** bytes in the string, not the number of characters.
4862: **
4863: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4864: ** even empty strings, are always zero-terminated. ^The return
4865: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4866: **
1.4 misho 4867: ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4868: ** [unprotected sqlite3_value] object. In a multithreaded environment,
4869: ** an unprotected sqlite3_value object may only be used safely with
4870: ** [sqlite3_bind_value()] and [sqlite3_result_value()].
1.2 misho 4871: ** If the [unprotected sqlite3_value] object returned by
4872: ** [sqlite3_column_value()] is used in any other way, including calls
4873: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
1.4 misho 4874: ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
1.5 misho 4875: ** Hence, the sqlite3_column_value() interface
4876: ** is normally only useful within the implementation of
4877: ** [application-defined SQL functions] or [virtual tables], not within
4878: ** top-level application code.
1.2 misho 4879: **
1.5 misho 4880: ** The these routines may attempt to convert the datatype of the result.
4881: ** ^For example, if the internal representation is FLOAT and a text result
1.2 misho 4882: ** is requested, [sqlite3_snprintf()] is used internally to perform the
4883: ** conversion automatically. ^(The following table details the conversions
4884: ** that are applied:
4885: **
4886: ** <blockquote>
4887: ** <table border="1">
4888: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4889: **
4890: ** <tr><td> NULL <td> INTEGER <td> Result is 0
4891: ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
1.4 misho 4892: ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4893: ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
1.2 misho 4894: ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4895: ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4896: ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
1.4 misho 4897: ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
1.2 misho 4898: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
1.4 misho 4899: ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4900: ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4901: ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
1.2 misho 4902: ** <tr><td> TEXT <td> BLOB <td> No change
1.4 misho 4903: ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4904: ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
1.2 misho 4905: ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4906: ** </table>
4907: ** </blockquote>)^
4908: **
4909: ** Note that when type conversions occur, pointers returned by prior
4910: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4911: ** sqlite3_column_text16() may be invalidated.
4912: ** Type conversions and pointer invalidations might occur
4913: ** in the following cases:
4914: **
4915: ** <ul>
4916: ** <li> The initial content is a BLOB and sqlite3_column_text() or
4917: ** sqlite3_column_text16() is called. A zero-terminator might
4918: ** need to be added to the string.</li>
4919: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4920: ** sqlite3_column_text16() is called. The content must be converted
4921: ** to UTF-16.</li>
4922: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4923: ** sqlite3_column_text() is called. The content must be converted
4924: ** to UTF-8.</li>
4925: ** </ul>
4926: **
4927: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4928: ** not invalidate a prior pointer, though of course the content of the buffer
4929: ** that the prior pointer references will have been modified. Other kinds
4930: ** of conversion are done in place when it is possible, but sometimes they
4931: ** are not possible and in those cases prior pointers are invalidated.
4932: **
1.4 misho 4933: ** The safest policy is to invoke these routines
1.2 misho 4934: ** in one of the following ways:
4935: **
4936: ** <ul>
4937: ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4938: ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4939: ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4940: ** </ul>
4941: **
4942: ** In other words, you should call sqlite3_column_text(),
4943: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4944: ** into the desired format, then invoke sqlite3_column_bytes() or
4945: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4946: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4947: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4948: ** with calls to sqlite3_column_bytes().
4949: **
4950: ** ^The pointers returned are valid until a type conversion occurs as
4951: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4952: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
1.5 misho 4953: ** and BLOBs is freed automatically. Do not pass the pointers returned
1.4 misho 4954: ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
1.2 misho 4955: ** [sqlite3_free()].
4956: **
1.5 misho 4957: ** As long as the input parameters are correct, these routines will only
4958: ** fail if an out-of-memory error occurs during a format conversion.
4959: ** Only the following subset of interfaces are subject to out-of-memory
4960: ** errors:
4961: **
4962: ** <ul>
4963: ** <li> sqlite3_column_blob()
4964: ** <li> sqlite3_column_text()
4965: ** <li> sqlite3_column_text16()
4966: ** <li> sqlite3_column_bytes()
4967: ** <li> sqlite3_column_bytes16()
4968: ** </ul>
4969: **
4970: ** If an out-of-memory error occurs, then the return value from these
4971: ** routines is the same as if the column had contained an SQL NULL value.
4972: ** Valid SQL NULL returns can be distinguished from out-of-memory errors
4973: ** by invoking the [sqlite3_errcode()] immediately after the suspect
4974: ** return value is obtained and before any
4975: ** other SQLite interface is called on the same [database connection].
1.2 misho 4976: */
4977: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4978: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4979: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4980: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4981: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4982: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
1.5 misho 4983: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4984: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4985: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
1.2 misho 4986: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4987:
4988: /*
4989: ** CAPI3REF: Destroy A Prepared Statement Object
1.4 misho 4990: ** DESTRUCTOR: sqlite3_stmt
1.2 misho 4991: **
4992: ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4993: ** ^If the most recent evaluation of the statement encountered no errors
4994: ** or if the statement is never been evaluated, then sqlite3_finalize() returns
4995: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4996: ** sqlite3_finalize(S) returns the appropriate [error code] or
4997: ** [extended error code].
4998: **
4999: ** ^The sqlite3_finalize(S) routine can be called at any point during
5000: ** the life cycle of [prepared statement] S:
5001: ** before statement S is ever evaluated, after
5002: ** one or more calls to [sqlite3_reset()], or after any call
5003: ** to [sqlite3_step()] regardless of whether or not the statement has
5004: ** completed execution.
5005: **
5006: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5007: **
5008: ** The application must finalize every [prepared statement] in order to avoid
5009: ** resource leaks. It is a grievous error for the application to try to use
5010: ** a prepared statement after it has been finalized. Any use of a prepared
5011: ** statement after it has been finalized can result in undefined and
5012: ** undesirable behavior such as segfaults and heap corruption.
5013: */
5014: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5015:
5016: /*
5017: ** CAPI3REF: Reset A Prepared Statement Object
1.4 misho 5018: ** METHOD: sqlite3_stmt
1.2 misho 5019: **
5020: ** The sqlite3_reset() function is called to reset a [prepared statement]
5021: ** object back to its initial state, ready to be re-executed.
5022: ** ^Any SQL statement variables that had values bound to them using
5023: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5024: ** Use [sqlite3_clear_bindings()] to reset the bindings.
5025: **
5026: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5027: ** back to the beginning of its program.
5028: **
5029: ** ^If the most recent call to [sqlite3_step(S)] for the
5030: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5031: ** or if [sqlite3_step(S)] has never before been called on S,
5032: ** then [sqlite3_reset(S)] returns [SQLITE_OK].
5033: **
5034: ** ^If the most recent call to [sqlite3_step(S)] for the
5035: ** [prepared statement] S indicated an error, then
5036: ** [sqlite3_reset(S)] returns an appropriate [error code].
5037: **
5038: ** ^The [sqlite3_reset(S)] interface does not change the values
5039: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5040: */
5041: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5042:
5043: /*
5044: ** CAPI3REF: Create Or Redefine SQL Functions
5045: ** KEYWORDS: {function creation routines}
1.4 misho 5046: ** METHOD: sqlite3
1.2 misho 5047: **
5048: ** ^These functions (collectively known as "function creation routines")
5049: ** are used to add SQL functions or aggregates or to redefine the behavior
1.5 misho 5050: ** of existing SQL functions or aggregates. The only differences between
5051: ** the three "sqlite3_create_function*" routines are the text encoding
5052: ** expected for the second parameter (the name of the function being
5053: ** created) and the presence or absence of a destructor callback for
5054: ** the application data pointer. Function sqlite3_create_window_function()
5055: ** is similar, but allows the user to supply the extra callback functions
5056: ** needed by [aggregate window functions].
1.2 misho 5057: **
5058: ** ^The first parameter is the [database connection] to which the SQL
5059: ** function is to be added. ^If an application uses more than one database
5060: ** connection then application-defined SQL functions must be added
5061: ** to each database connection separately.
5062: **
5063: ** ^The second parameter is the name of the SQL function to be created or
5064: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5065: ** representation, exclusive of the zero-terminator. ^Note that the name
1.5 misho 5066: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
1.2 misho 5067: ** ^Any attempt to create a function with a longer name
5068: ** will result in [SQLITE_MISUSE] being returned.
5069: **
5070: ** ^The third parameter (nArg)
5071: ** is the number of arguments that the SQL function or
5072: ** aggregate takes. ^If this parameter is -1, then the SQL function or
5073: ** aggregate may take any number of arguments between 0 and the limit
5074: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5075: ** parameter is less than -1 or greater than 127 then the behavior is
5076: ** undefined.
5077: **
5078: ** ^The fourth parameter, eTextRep, specifies what
5079: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
1.4 misho 5080: ** its parameters. The application should set this parameter to
1.5 misho 5081: ** [SQLITE_UTF16LE] if the function implementation invokes
1.4 misho 5082: ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5083: ** implementation invokes [sqlite3_value_text16be()] on an input, or
5084: ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5085: ** otherwise. ^The same SQL function may be registered multiple times using
5086: ** different preferred text encodings, with different implementations for
5087: ** each encoding.
1.2 misho 5088: ** ^When multiple implementations of the same function are available, SQLite
5089: ** will pick the one that involves the least amount of data conversion.
1.4 misho 5090: **
5091: ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5092: ** to signal that the function will always return the same result given
5093: ** the same inputs within a single SQL statement. Most SQL functions are
5094: ** deterministic. The built-in [random()] SQL function is an example of a
5095: ** function that is not deterministic. The SQLite query planner is able to
5096: ** perform additional optimizations on deterministic functions, so use
5097: ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
1.2 misho 5098: **
1.5 misho 5099: ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5100: ** flag, which if present prevents the function from being invoked from
5101: ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5102: ** index expressions, or the WHERE clause of partial indexes.
5103: **
5104: ** <span style="background-color:#ffff90;">
5105: ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5106: ** all application-defined SQL functions that do not need to be
5107: ** used inside of triggers, view, CHECK constraints, or other elements of
5108: ** the database schema. This flags is especially recommended for SQL
5109: ** functions that have side effects or reveal internal application state.
5110: ** Without this flag, an attacker might be able to modify the schema of
5111: ** a database file to include invocations of the function with parameters
5112: ** chosen by the attacker, which the application will then execute when
5113: ** the database file is opened and read.
5114: ** </span>
5115: **
1.2 misho 5116: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5117: ** function can gain access to this pointer using [sqlite3_user_data()].)^
5118: **
1.5 misho 5119: ** ^The sixth, seventh and eighth parameters passed to the three
5120: ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
1.2 misho 5121: ** pointers to C-language functions that implement the SQL function or
5122: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5123: ** callback only; NULL pointers must be passed as the xStep and xFinal
5124: ** parameters. ^An aggregate SQL function requires an implementation of xStep
5125: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5126: ** SQL function or aggregate, pass NULL pointers for all three function
5127: ** callbacks.
5128: **
1.5 misho 5129: ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5130: ** and xInverse) passed to sqlite3_create_window_function are pointers to
5131: ** C-language callbacks that implement the new function. xStep and xFinal
5132: ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5133: ** which case a regular aggregate function is created, or must both be
5134: ** non-NULL, in which case the new function may be used as either an aggregate
5135: ** or aggregate window function. More details regarding the implementation
5136: ** of aggregate window functions are
5137: ** [user-defined window functions|available here].
5138: **
5139: ** ^(If the final parameter to sqlite3_create_function_v2() or
5140: ** sqlite3_create_window_function() is not NULL, then it is destructor for
5141: ** the application data pointer. The destructor is invoked when the function
5142: ** is deleted, either by being overloaded or when the database connection
5143: ** closes.)^ ^The destructor is also invoked if the call to
5144: ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5145: ** invoked, it is passed a single argument which is a copy of the application
5146: ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
1.2 misho 5147: **
5148: ** ^It is permitted to register multiple implementations of the same
5149: ** functions with the same name but with either differing numbers of
5150: ** arguments or differing preferred text encodings. ^SQLite will use
5151: ** the implementation that most closely matches the way in which the
5152: ** SQL function is used. ^A function implementation with a non-negative
5153: ** nArg parameter is a better match than a function implementation with
5154: ** a negative nArg. ^A function where the preferred text encoding
5155: ** matches the database encoding is a better
1.5 misho 5156: ** match than a function where the encoding is different.
1.2 misho 5157: ** ^A function where the encoding difference is between UTF16le and UTF16be
5158: ** is a closer match than a function where the encoding difference is
5159: ** between UTF8 and UTF16.
5160: **
5161: ** ^Built-in functions may be overloaded by new application-defined functions.
5162: **
5163: ** ^An application-defined function is permitted to call other
5164: ** SQLite interfaces. However, such calls must not
5165: ** close the database connection nor finalize or reset the prepared
5166: ** statement in which the function is running.
5167: */
5168: SQLITE_API int sqlite3_create_function(
5169: sqlite3 *db,
5170: const char *zFunctionName,
5171: int nArg,
5172: int eTextRep,
5173: void *pApp,
5174: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5175: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5176: void (*xFinal)(sqlite3_context*)
5177: );
5178: SQLITE_API int sqlite3_create_function16(
5179: sqlite3 *db,
5180: const void *zFunctionName,
5181: int nArg,
5182: int eTextRep,
5183: void *pApp,
5184: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5185: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5186: void (*xFinal)(sqlite3_context*)
5187: );
5188: SQLITE_API int sqlite3_create_function_v2(
5189: sqlite3 *db,
5190: const char *zFunctionName,
5191: int nArg,
5192: int eTextRep,
5193: void *pApp,
5194: void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5195: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5196: void (*xFinal)(sqlite3_context*),
5197: void(*xDestroy)(void*)
5198: );
1.5 misho 5199: SQLITE_API int sqlite3_create_window_function(
5200: sqlite3 *db,
5201: const char *zFunctionName,
5202: int nArg,
5203: int eTextRep,
5204: void *pApp,
5205: void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5206: void (*xFinal)(sqlite3_context*),
5207: void (*xValue)(sqlite3_context*),
5208: void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5209: void(*xDestroy)(void*)
5210: );
1.2 misho 5211:
5212: /*
5213: ** CAPI3REF: Text Encodings
5214: **
5215: ** These constant define integer codes that represent the various
5216: ** text encodings supported by SQLite.
5217: */
1.4 misho 5218: #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5219: #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5220: #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
1.2 misho 5221: #define SQLITE_UTF16 4 /* Use native byte order */
1.4 misho 5222: #define SQLITE_ANY 5 /* Deprecated */
1.2 misho 5223: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5224:
5225: /*
1.4 misho 5226: ** CAPI3REF: Function Flags
5227: **
1.5 misho 5228: ** These constants may be ORed together with the
1.4 misho 5229: ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5230: ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5231: ** [sqlite3_create_function_v2()].
1.5 misho 5232: **
5233: ** <dl>
5234: ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5235: ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5236: ** the same output when the input parameters are the same.
5237: ** The [abs|abs() function] is deterministic, for example, but
5238: ** [randomblob|randomblob()] is not. Functions must
5239: ** be deterministic in order to be used in certain contexts such as
5240: ** with the WHERE clause of [partial indexes] or in [generated columns].
5241: ** SQLite might also optimize deterministic functions by factoring them
5242: ** out of inner loops.
5243: ** </dd>
5244: **
5245: ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5246: ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5247: ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5248: ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5249: ** [expression indexes], [partial indexes], or [generated columns].
5250: ** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5251: ** for all [application-defined SQL functions], and especially for functions
5252: ** that have side-effects or that could potentially leak sensitive
5253: ** information.
5254: ** </dd>
5255: **
5256: ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5257: ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5258: ** to cause problems even if misused. An innocuous function should have
5259: ** no side effects and should not depend on any values other than its
5260: ** input parameters. The [abs|abs() function] is an example of an
5261: ** innocuous function.
5262: ** The [load_extension() SQL function] is not innocuous because of its
5263: ** side effects.
5264: ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5265: ** exactly the same. The [random|random() function] is an example of a
5266: ** function that is innocuous but not deterministic.
5267: ** <p>Some heightened security settings
5268: ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5269: ** disable the use of SQL functions inside views and triggers and in
5270: ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5271: ** [expression indexes], [partial indexes], and [generated columns] unless
5272: ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5273: ** are innocuous. Developers are advised to avoid using the
5274: ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5275: ** function has been carefully audited and found to be free of potentially
5276: ** security-adverse side-effects and information-leaks.
5277: ** </dd>
5278: **
5279: ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5280: ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5281: ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5282: ** Specifying this flag makes no difference for scalar or aggregate user
5283: ** functions. However, if it is not specified for a user-defined window
5284: ** function, then any sub-types belonging to arguments passed to the window
5285: ** function may be discarded before the window function is called (i.e.
5286: ** sqlite3_value_subtype() will always return 0).
5287: ** </dd>
5288: ** </dl>
1.4 misho 5289: */
1.5 misho 5290: #define SQLITE_DETERMINISTIC 0x000000800
5291: #define SQLITE_DIRECTONLY 0x000080000
5292: #define SQLITE_SUBTYPE 0x000100000
5293: #define SQLITE_INNOCUOUS 0x000200000
1.4 misho 5294:
5295: /*
1.2 misho 5296: ** CAPI3REF: Deprecated Functions
5297: ** DEPRECATED
5298: **
5299: ** These functions are [deprecated]. In order to maintain
1.5 misho 5300: ** backwards compatibility with older code, these functions continue
1.2 misho 5301: ** to be supported. However, new applications should avoid
1.4 misho 5302: ** the use of these functions. To encourage programmers to avoid
5303: ** these functions, we will not explain what they do.
1.2 misho 5304: */
5305: #ifndef SQLITE_OMIT_DEPRECATED
5306: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5307: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5308: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5309: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5310: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
1.4 misho 5311: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5312: void*,sqlite3_int64);
1.2 misho 5313: #endif
5314:
5315: /*
1.4 misho 5316: ** CAPI3REF: Obtaining SQL Values
5317: ** METHOD: sqlite3_value
1.2 misho 5318: **
1.5 misho 5319: ** <b>Summary:</b>
5320: ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5321: ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5322: ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5323: ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5324: ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5325: ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5326: ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5327: ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5328: ** the native byteorder
5329: ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5330: ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5331: ** <tr><td> <td> <td>
5332: ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5333: ** or a UTF-8 TEXT in bytes
5334: ** <tr><td><b>sqlite3_value_bytes16 </b>
5335: ** <td>→ <td>Size of UTF-16
5336: ** TEXT in bytes
5337: ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5338: ** datatype of the value
5339: ** <tr><td><b>sqlite3_value_numeric_type </b>
5340: ** <td>→ <td>Best numeric datatype of the value
5341: ** <tr><td><b>sqlite3_value_nochange </b>
5342: ** <td>→ <td>True if the column is unchanged in an UPDATE
5343: ** against a virtual table.
5344: ** <tr><td><b>sqlite3_value_frombind </b>
5345: ** <td>→ <td>True if value originated from a [bound parameter]
5346: ** </table></blockquote>
5347: **
5348: ** <b>Details:</b>
5349: **
5350: ** These routines extract type, size, and content information from
5351: ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5352: ** are used to pass parameter information into the functions that
5353: ** implement [application-defined SQL functions] and [virtual tables].
1.2 misho 5354: **
5355: ** These routines work only with [protected sqlite3_value] objects.
5356: ** Any attempt to use these routines on an [unprotected sqlite3_value]
1.5 misho 5357: ** is not threadsafe.
1.2 misho 5358: **
5359: ** ^These routines work just like the corresponding [column access functions]
1.4 misho 5360: ** except that these routines take a single [protected sqlite3_value] object
1.2 misho 5361: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5362: **
5363: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5364: ** in the native byte-order of the host machine. ^The
5365: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5366: ** extract UTF-16 strings as big-endian and little-endian respectively.
5367: **
1.5 misho 5368: ** ^If [sqlite3_value] object V was initialized
5369: ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5370: ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5371: ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5372: ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5373: ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5374: **
5375: ** ^(The sqlite3_value_type(V) interface returns the
5376: ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5377: ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5378: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5379: ** Other interfaces might change the datatype for an sqlite3_value object.
5380: ** For example, if the datatype is initially SQLITE_INTEGER and
5381: ** sqlite3_value_text(V) is called to extract a text value for that
5382: ** integer, then subsequent calls to sqlite3_value_type(V) might return
5383: ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5384: ** occurs is undefined and may change from one release of SQLite to the next.
5385: **
1.2 misho 5386: ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5387: ** numeric affinity to the value. This means that an attempt is
5388: ** made to convert the value to an integer or floating point. If
5389: ** such a conversion is possible without loss of information (in other
5390: ** words, if the value is a string that looks like a number)
5391: ** then the conversion is performed. Otherwise no conversion occurs.
5392: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5393: **
1.5 misho 5394: ** ^Within the [xUpdate] method of a [virtual table], the
5395: ** sqlite3_value_nochange(X) interface returns true if and only if
5396: ** the column corresponding to X is unchanged by the UPDATE operation
5397: ** that the xUpdate method call was invoked to implement and if
5398: ** and the prior [xColumn] method call that was invoked to extracted
5399: ** the value for that column returned without setting a result (probably
5400: ** because it queried [sqlite3_vtab_nochange()] and found that the column
5401: ** was unchanging). ^Within an [xUpdate] method, any value for which
5402: ** sqlite3_value_nochange(X) is true will in all other respects appear
5403: ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5404: ** than within an [xUpdate] method call for an UPDATE statement, then
5405: ** the return value is arbitrary and meaningless.
5406: **
5407: ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5408: ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5409: ** interfaces. ^If X comes from an SQL literal value, or a table column,
5410: ** or an expression, then sqlite3_value_frombind(X) returns zero.
5411: **
1.2 misho 5412: ** Please pay particular attention to the fact that the pointer returned
5413: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5414: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5415: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5416: ** or [sqlite3_value_text16()].
5417: **
5418: ** These routines must be called from the same thread as
5419: ** the SQL function that supplied the [sqlite3_value*] parameters.
1.5 misho 5420: **
5421: ** As long as the input parameter is correct, these routines can only
5422: ** fail if an out-of-memory error occurs during a format conversion.
5423: ** Only the following subset of interfaces are subject to out-of-memory
5424: ** errors:
5425: **
5426: ** <ul>
5427: ** <li> sqlite3_value_blob()
5428: ** <li> sqlite3_value_text()
5429: ** <li> sqlite3_value_text16()
5430: ** <li> sqlite3_value_text16le()
5431: ** <li> sqlite3_value_text16be()
5432: ** <li> sqlite3_value_bytes()
5433: ** <li> sqlite3_value_bytes16()
5434: ** </ul>
5435: **
5436: ** If an out-of-memory error occurs, then the return value from these
5437: ** routines is the same as if the column had contained an SQL NULL value.
5438: ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5439: ** by invoking the [sqlite3_errcode()] immediately after the suspect
5440: ** return value is obtained and before any
5441: ** other SQLite interface is called on the same [database connection].
1.2 misho 5442: */
5443: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5444: SQLITE_API double sqlite3_value_double(sqlite3_value*);
5445: SQLITE_API int sqlite3_value_int(sqlite3_value*);
5446: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
1.5 misho 5447: SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
1.2 misho 5448: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5449: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5450: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5451: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
1.5 misho 5452: SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5453: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
1.2 misho 5454: SQLITE_API int sqlite3_value_type(sqlite3_value*);
5455: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
1.5 misho 5456: SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5457: SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
1.2 misho 5458:
5459: /*
1.4 misho 5460: ** CAPI3REF: Finding The Subtype Of SQL Values
5461: ** METHOD: sqlite3_value
5462: **
5463: ** The sqlite3_value_subtype(V) function returns the subtype for
5464: ** an [application-defined SQL function] argument V. The subtype
5465: ** information can be used to pass a limited amount of context from
5466: ** one SQL function to another. Use the [sqlite3_result_subtype()]
5467: ** routine to set the subtype for the return value of an SQL function.
5468: */
5469: SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5470:
5471: /*
5472: ** CAPI3REF: Copy And Free SQL Values
5473: ** METHOD: sqlite3_value
5474: **
5475: ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5476: ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5477: ** is a [protected sqlite3_value] object even if the input is not.
5478: ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5479: ** memory allocation fails.
5480: **
5481: ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5482: ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5483: ** then sqlite3_value_free(V) is a harmless no-op.
5484: */
5485: SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5486: SQLITE_API void sqlite3_value_free(sqlite3_value*);
5487:
5488: /*
1.2 misho 5489: ** CAPI3REF: Obtain Aggregate Function Context
1.4 misho 5490: ** METHOD: sqlite3_context
1.2 misho 5491: **
5492: ** Implementations of aggregate SQL functions use this
5493: ** routine to allocate memory for storing their state.
5494: **
1.5 misho 5495: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5496: ** for a particular aggregate function, SQLite allocates
5497: ** N bytes of memory, zeroes out that memory, and returns a pointer
1.2 misho 5498: ** to the new memory. ^On second and subsequent calls to
5499: ** sqlite3_aggregate_context() for the same aggregate function instance,
5500: ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5501: ** called once for each invocation of the xStep callback and then one
5502: ** last time when the xFinal callback is invoked. ^(When no rows match
5503: ** an aggregate query, the xStep() callback of the aggregate function
5504: ** implementation is never called and xFinal() is called exactly once.
5505: ** In those cases, sqlite3_aggregate_context() might be called for the
5506: ** first time from within xFinal().)^
5507: **
1.5 misho 5508: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
1.4 misho 5509: ** when first called if N is less than or equal to zero or if a memory
5510: ** allocate error occurs.
1.2 misho 5511: **
5512: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5513: ** determined by the N parameter on first successful call. Changing the
1.5 misho 5514: ** value of N in any subsequent call to sqlite3_aggregate_context() within
1.2 misho 5515: ** the same aggregate function instance will not resize the memory
1.4 misho 5516: ** allocation.)^ Within the xFinal callback, it is customary to set
1.5 misho 5517: ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
1.4 misho 5518: ** pointless memory allocations occur.
1.2 misho 5519: **
1.5 misho 5520: ** ^SQLite automatically frees the memory allocated by
1.2 misho 5521: ** sqlite3_aggregate_context() when the aggregate query concludes.
5522: **
5523: ** The first parameter must be a copy of the
5524: ** [sqlite3_context | SQL function context] that is the first parameter
5525: ** to the xStep or xFinal callback routine that implements the aggregate
5526: ** function.
5527: **
5528: ** This routine must be called from the same thread in which
5529: ** the aggregate SQL function is running.
5530: */
5531: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5532:
5533: /*
5534: ** CAPI3REF: User Data For Functions
1.4 misho 5535: ** METHOD: sqlite3_context
1.2 misho 5536: **
5537: ** ^The sqlite3_user_data() interface returns a copy of
5538: ** the pointer that was the pUserData parameter (the 5th parameter)
5539: ** of the [sqlite3_create_function()]
5540: ** and [sqlite3_create_function16()] routines that originally
5541: ** registered the application defined function.
5542: **
5543: ** This routine must be called from the same thread in which
5544: ** the application-defined function is running.
5545: */
5546: SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5547:
5548: /*
5549: ** CAPI3REF: Database Connection For Functions
1.4 misho 5550: ** METHOD: sqlite3_context
1.2 misho 5551: **
5552: ** ^The sqlite3_context_db_handle() interface returns a copy of
5553: ** the pointer to the [database connection] (the 1st parameter)
5554: ** of the [sqlite3_create_function()]
5555: ** and [sqlite3_create_function16()] routines that originally
5556: ** registered the application defined function.
5557: */
5558: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5559:
5560: /*
5561: ** CAPI3REF: Function Auxiliary Data
1.4 misho 5562: ** METHOD: sqlite3_context
1.2 misho 5563: **
1.4 misho 5564: ** These functions may be used by (non-aggregate) SQL functions to
1.2 misho 5565: ** associate metadata with argument values. If the same value is passed to
5566: ** multiple invocations of the same SQL function during query execution, under
1.4 misho 5567: ** some circumstances the associated metadata may be preserved. An example
5568: ** of where this might be useful is in a regular-expression matching
5569: ** function. The compiled version of the regular expression can be stored as
1.5 misho 5570: ** metadata associated with the pattern string.
1.4 misho 5571: ** Then as long as the pattern string remains the same,
5572: ** the compiled regular expression can be reused on multiple
5573: ** invocations of the same function.
1.2 misho 5574: **
1.5 misho 5575: ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5576: ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5577: ** value to the application-defined function. ^N is zero for the left-most
5578: ** function argument. ^If there is no metadata
5579: ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
1.4 misho 5580: ** returns a NULL pointer.
5581: **
5582: ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5583: ** argument of the application-defined function. ^Subsequent
5584: ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5585: ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5586: ** NULL if the metadata has been discarded.
5587: ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5588: ** SQLite will invoke the destructor function X with parameter P exactly
5589: ** once, when the metadata is discarded.
5590: ** SQLite is free to discard the metadata at any time, including: <ul>
5591: ** <li> ^(when the corresponding function parameter changes)^, or
5592: ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5593: ** SQL statement)^, or
5594: ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5595: ** parameter)^, or
1.5 misho 5596: ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
1.4 misho 5597: ** allocation error occurs.)^ </ul>
5598: **
1.5 misho 5599: ** Note the last bullet in particular. The destructor X in
1.4 misho 5600: ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5601: ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5602: ** should be called near the end of the function implementation and the
5603: ** function implementation should not make any use of P after
5604: ** sqlite3_set_auxdata() has been called.
1.2 misho 5605: **
5606: ** ^(In practice, metadata is preserved between function calls for
1.4 misho 5607: ** function parameters that are compile-time constants, including literal
5608: ** values and [parameters] and expressions composed from the same.)^
1.2 misho 5609: **
1.5 misho 5610: ** The value of the N parameter to these interfaces should be non-negative.
5611: ** Future enhancements may make use of negative N values to define new
5612: ** kinds of function caching behavior.
5613: **
1.2 misho 5614: ** These routines must be called from the same thread in which
5615: ** the SQL function is running.
5616: */
5617: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5618: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5619:
5620:
5621: /*
5622: ** CAPI3REF: Constants Defining Special Destructor Behavior
5623: **
5624: ** These are special values for the destructor that is passed in as the
5625: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5626: ** argument is SQLITE_STATIC, it means that the content pointer is constant
5627: ** and will never change. It does not need to be destroyed. ^The
5628: ** SQLITE_TRANSIENT value means that the content will likely change in
5629: ** the near future and that SQLite should make its own private copy of
5630: ** the content before returning.
5631: **
5632: ** The typedef is necessary to work around problems in certain
1.4 misho 5633: ** C++ compilers.
1.2 misho 5634: */
5635: typedef void (*sqlite3_destructor_type)(void*);
5636: #define SQLITE_STATIC ((sqlite3_destructor_type)0)
5637: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5638:
5639: /*
5640: ** CAPI3REF: Setting The Result Of An SQL Function
1.4 misho 5641: ** METHOD: sqlite3_context
1.2 misho 5642: **
5643: ** These routines are used by the xFunc or xFinal callbacks that
5644: ** implement SQL functions and aggregates. See
5645: ** [sqlite3_create_function()] and [sqlite3_create_function16()]
5646: ** for additional information.
5647: **
5648: ** These functions work very much like the [parameter binding] family of
5649: ** functions used to bind values to host parameters in prepared statements.
5650: ** Refer to the [SQL parameter] documentation for additional information.
5651: **
5652: ** ^The sqlite3_result_blob() interface sets the result from
5653: ** an application-defined function to be the BLOB whose content is pointed
5654: ** to by the second parameter and which is N bytes long where N is the
5655: ** third parameter.
5656: **
1.4 misho 5657: ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5658: ** interfaces set the result of the application-defined function to be
5659: ** a BLOB containing all zero bytes and N bytes in size.
1.2 misho 5660: **
5661: ** ^The sqlite3_result_double() interface sets the result from
5662: ** an application-defined function to be a floating point value specified
5663: ** by its 2nd argument.
5664: **
5665: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5666: ** cause the implemented SQL function to throw an exception.
5667: ** ^SQLite uses the string pointed to by the
5668: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5669: ** as the text of an error message. ^SQLite interprets the error
5670: ** message string from sqlite3_result_error() as UTF-8. ^SQLite
1.5 misho 5671: ** interprets the string from sqlite3_result_error16() as UTF-16 using
5672: ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5673: ** ^If the third parameter to sqlite3_result_error()
1.2 misho 5674: ** or sqlite3_result_error16() is negative then SQLite takes as the error
5675: ** message all text up through the first zero character.
5676: ** ^If the third parameter to sqlite3_result_error() or
5677: ** sqlite3_result_error16() is non-negative then SQLite takes that many
5678: ** bytes (not characters) from the 2nd parameter as the error message.
5679: ** ^The sqlite3_result_error() and sqlite3_result_error16()
5680: ** routines make a private copy of the error message text before
5681: ** they return. Hence, the calling function can deallocate or
5682: ** modify the text after they return without harm.
5683: ** ^The sqlite3_result_error_code() function changes the error code
5684: ** returned by SQLite as a result of an error in a function. ^By default,
5685: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5686: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5687: **
1.3 misho 5688: ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5689: ** error indicating that a string or BLOB is too long to represent.
1.2 misho 5690: **
1.3 misho 5691: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5692: ** error indicating that a memory allocation failed.
1.2 misho 5693: **
5694: ** ^The sqlite3_result_int() interface sets the return value
5695: ** of the application-defined function to be the 32-bit signed integer
5696: ** value given in the 2nd argument.
5697: ** ^The sqlite3_result_int64() interface sets the return value
5698: ** of the application-defined function to be the 64-bit signed integer
5699: ** value given in the 2nd argument.
5700: **
5701: ** ^The sqlite3_result_null() interface sets the return value
5702: ** of the application-defined function to be NULL.
5703: **
5704: ** ^The sqlite3_result_text(), sqlite3_result_text16(),
5705: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5706: ** set the return value of the application-defined function to be
5707: ** a text string which is represented as UTF-8, UTF-16 native byte order,
5708: ** UTF-16 little endian, or UTF-16 big endian, respectively.
1.4 misho 5709: ** ^The sqlite3_result_text64() interface sets the return value of an
5710: ** application-defined function to be a text string in an encoding
5711: ** specified by the fifth (and last) parameter, which must be one
5712: ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
1.2 misho 5713: ** ^SQLite takes the text result from the application from
5714: ** the 2nd parameter of the sqlite3_result_text* interfaces.
5715: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5716: ** is negative, then SQLite takes result text from the 2nd parameter
5717: ** through the first zero character.
5718: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5719: ** is non-negative, then as many bytes (not characters) of the text
5720: ** pointed to by the 2nd parameter are taken as the application-defined
5721: ** function result. If the 3rd parameter is non-negative, then it
5722: ** must be the byte offset into the string where the NUL terminator would
5723: ** appear if the string where NUL terminated. If any NUL characters occur
5724: ** in the string at a byte offset that is less than the value of the 3rd
5725: ** parameter, then the resulting string will contain embedded NULs and the
5726: ** result of expressions operating on strings with embedded NULs is undefined.
5727: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5728: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5729: ** function as the destructor on the text or BLOB result when it has
5730: ** finished using that result.
5731: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5732: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5733: ** assumes that the text or BLOB result is in constant space and does not
5734: ** copy the content of the parameter nor call a destructor on the content
5735: ** when it has finished using that result.
5736: ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5737: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
1.5 misho 5738: ** then SQLite makes a copy of the result into space obtained
1.2 misho 5739: ** from [sqlite3_malloc()] before it returns.
5740: **
1.5 misho 5741: ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5742: ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5743: ** when the encoding is not UTF8, if the input UTF16 begins with a
5744: ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5745: ** string and the rest of the string is interpreted according to the
5746: ** byte-order specified by the BOM. ^The byte-order specified by
5747: ** the BOM at the beginning of the text overrides the byte-order
5748: ** specified by the interface procedure. ^So, for example, if
5749: ** sqlite3_result_text16le() is invoked with text that begins
5750: ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5751: ** first two bytes of input are skipped and the remaining input
5752: ** is interpreted as UTF16BE text.
5753: **
5754: ** ^For UTF16 input text to the sqlite3_result_text16(),
5755: ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5756: ** sqlite3_result_text64() routines, if the text contains invalid
5757: ** UTF16 characters, the invalid characters might be converted
5758: ** into the unicode replacement character, U+FFFD.
5759: **
1.2 misho 5760: ** ^The sqlite3_result_value() interface sets the result of
1.4 misho 5761: ** the application-defined function to be a copy of the
1.2 misho 5762: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5763: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5764: ** so that the [sqlite3_value] specified in the parameter may change or
5765: ** be deallocated after sqlite3_result_value() returns without harm.
5766: ** ^A [protected sqlite3_value] object may always be used where an
5767: ** [unprotected sqlite3_value] object is required, so either
5768: ** kind of [sqlite3_value] object can be used with this interface.
5769: **
1.5 misho 5770: ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5771: ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5772: ** also associates the host-language pointer P or type T with that
5773: ** NULL value such that the pointer can be retrieved within an
5774: ** [application-defined SQL function] using [sqlite3_value_pointer()].
5775: ** ^If the D parameter is not NULL, then it is a pointer to a destructor
5776: ** for the P parameter. ^SQLite invokes D with P as its only argument
5777: ** when SQLite is finished with P. The T parameter should be a static
5778: ** string and preferably a string literal. The sqlite3_result_pointer()
5779: ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5780: **
1.2 misho 5781: ** If these routines are called from within the different thread
5782: ** than the one containing the application-defined function that received
5783: ** the [sqlite3_context] pointer, the results are undefined.
5784: */
5785: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
1.4 misho 5786: SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5787: sqlite3_uint64,void(*)(void*));
1.2 misho 5788: SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5789: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5790: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5791: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5792: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5793: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5794: SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5795: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5796: SQLITE_API void sqlite3_result_null(sqlite3_context*);
5797: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
1.4 misho 5798: SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5799: void(*)(void*), unsigned char encoding);
1.2 misho 5800: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5801: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5802: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5803: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
1.5 misho 5804: SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
1.2 misho 5805: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
1.4 misho 5806: SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5807:
5808:
5809: /*
5810: ** CAPI3REF: Setting The Subtype Of An SQL Function
5811: ** METHOD: sqlite3_context
5812: **
5813: ** The sqlite3_result_subtype(C,T) function causes the subtype of
1.5 misho 5814: ** the result from the [application-defined SQL function] with
5815: ** [sqlite3_context] C to be the value T. Only the lower 8 bits
1.4 misho 5816: ** of the subtype T are preserved in current versions of SQLite;
5817: ** higher order bits are discarded.
5818: ** The number of subtype bytes preserved by SQLite might increase
5819: ** in future releases of SQLite.
5820: */
5821: SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
1.2 misho 5822:
5823: /*
5824: ** CAPI3REF: Define New Collating Sequences
1.4 misho 5825: ** METHOD: sqlite3
1.2 misho 5826: **
5827: ** ^These functions add, remove, or modify a [collation] associated
5828: ** with the [database connection] specified as the first argument.
5829: **
5830: ** ^The name of the collation is a UTF-8 string
5831: ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5832: ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5833: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5834: ** considered to be the same name.
5835: **
5836: ** ^(The third argument (eTextRep) must be one of the constants:
5837: ** <ul>
5838: ** <li> [SQLITE_UTF8],
5839: ** <li> [SQLITE_UTF16LE],
5840: ** <li> [SQLITE_UTF16BE],
5841: ** <li> [SQLITE_UTF16], or
5842: ** <li> [SQLITE_UTF16_ALIGNED].
5843: ** </ul>)^
5844: ** ^The eTextRep argument determines the encoding of strings passed
1.5 misho 5845: ** to the collating function callback, xCompare.
1.2 misho 5846: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5847: ** force strings to be UTF16 with native byte order.
5848: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5849: ** on an even byte address.
5850: **
5851: ** ^The fourth argument, pArg, is an application data pointer that is passed
5852: ** through as the first argument to the collating function callback.
5853: **
1.5 misho 5854: ** ^The fifth argument, xCompare, is a pointer to the collating function.
1.2 misho 5855: ** ^Multiple collating functions can be registered using the same name but
5856: ** with different eTextRep parameters and SQLite will use whichever
5857: ** function requires the least amount of data transformation.
1.5 misho 5858: ** ^If the xCompare argument is NULL then the collating function is
1.2 misho 5859: ** deleted. ^When all collating functions having the same name are deleted,
5860: ** that collation is no longer usable.
5861: **
1.5 misho 5862: ** ^The collating function callback is invoked with a copy of the pArg
1.2 misho 5863: ** application data pointer and with two strings in the encoding specified
1.5 misho 5864: ** by the eTextRep argument. The two integer parameters to the collating
5865: ** function callback are the length of the two strings, in bytes. The collating
5866: ** function must return an integer that is negative, zero, or positive
1.2 misho 5867: ** if the first string is less than, equal to, or greater than the second,
5868: ** respectively. A collating function must always return the same answer
5869: ** given the same inputs. If two or more collating functions are registered
5870: ** to the same collation name (using different eTextRep values) then all
5871: ** must give an equivalent answer when invoked with equivalent strings.
5872: ** The collating function must obey the following properties for all
5873: ** strings A, B, and C:
5874: **
5875: ** <ol>
5876: ** <li> If A==B then B==A.
5877: ** <li> If A==B and B==C then A==C.
5878: ** <li> If A<B THEN B>A.
5879: ** <li> If A<B and B<C then A<C.
5880: ** </ol>
5881: **
5882: ** If a collating function fails any of the above constraints and that
1.5 misho 5883: ** collating function is registered and used, then the behavior of SQLite
1.2 misho 5884: ** is undefined.
5885: **
5886: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5887: ** with the addition that the xDestroy callback is invoked on pArg when
5888: ** the collating function is deleted.
5889: ** ^Collating functions are deleted when they are overridden by later
5890: ** calls to the collation creation functions or when the
5891: ** [database connection] is closed using [sqlite3_close()].
5892: **
1.5 misho 5893: ** ^The xDestroy callback is <u>not</u> called if the
1.2 misho 5894: ** sqlite3_create_collation_v2() function fails. Applications that invoke
1.5 misho 5895: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
1.2 misho 5896: ** check the return code and dispose of the application data pointer
5897: ** themselves rather than expecting SQLite to deal with it for them.
1.5 misho 5898: ** This is different from every other SQLite interface. The inconsistency
5899: ** is unfortunate but cannot be changed without breaking backwards
1.2 misho 5900: ** compatibility.
5901: **
5902: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5903: */
5904: SQLITE_API int sqlite3_create_collation(
1.5 misho 5905: sqlite3*,
5906: const char *zName,
5907: int eTextRep,
1.2 misho 5908: void *pArg,
5909: int(*xCompare)(void*,int,const void*,int,const void*)
5910: );
5911: SQLITE_API int sqlite3_create_collation_v2(
1.5 misho 5912: sqlite3*,
5913: const char *zName,
5914: int eTextRep,
1.2 misho 5915: void *pArg,
5916: int(*xCompare)(void*,int,const void*,int,const void*),
5917: void(*xDestroy)(void*)
5918: );
5919: SQLITE_API int sqlite3_create_collation16(
1.5 misho 5920: sqlite3*,
1.2 misho 5921: const void *zName,
1.5 misho 5922: int eTextRep,
1.2 misho 5923: void *pArg,
5924: int(*xCompare)(void*,int,const void*,int,const void*)
5925: );
5926:
5927: /*
5928: ** CAPI3REF: Collation Needed Callbacks
1.4 misho 5929: ** METHOD: sqlite3
1.2 misho 5930: **
5931: ** ^To avoid having to register all collation sequences before a database
5932: ** can be used, a single callback function may be registered with the
5933: ** [database connection] to be invoked whenever an undefined collation
5934: ** sequence is required.
5935: **
5936: ** ^If the function is registered using the sqlite3_collation_needed() API,
5937: ** then it is passed the names of undefined collation sequences as strings
5938: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5939: ** the names are passed as UTF-16 in machine native byte order.
5940: ** ^A call to either function replaces the existing collation-needed callback.
5941: **
5942: ** ^(When the callback is invoked, the first argument passed is a copy
5943: ** of the second argument to sqlite3_collation_needed() or
5944: ** sqlite3_collation_needed16(). The second argument is the database
5945: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5946: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5947: ** sequence function required. The fourth parameter is the name of the
5948: ** required collation sequence.)^
5949: **
5950: ** The callback function should register the desired collation using
5951: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5952: ** [sqlite3_create_collation_v2()].
5953: */
5954: SQLITE_API int sqlite3_collation_needed(
1.5 misho 5955: sqlite3*,
5956: void*,
1.2 misho 5957: void(*)(void*,sqlite3*,int eTextRep,const char*)
5958: );
5959: SQLITE_API int sqlite3_collation_needed16(
1.5 misho 5960: sqlite3*,
1.2 misho 5961: void*,
5962: void(*)(void*,sqlite3*,int eTextRep,const void*)
5963: );
5964:
5965: #ifdef SQLITE_ENABLE_CEROD
5966: /*
1.5 misho 5967: ** Specify the activation key for a CEROD database. Unless
1.2 misho 5968: ** activated, none of the CEROD routines will work.
5969: */
5970: SQLITE_API void sqlite3_activate_cerod(
5971: const char *zPassPhrase /* Activation phrase */
5972: );
5973: #endif
5974:
5975: /*
5976: ** CAPI3REF: Suspend Execution For A Short Time
5977: **
5978: ** The sqlite3_sleep() function causes the current thread to suspend execution
5979: ** for at least a number of milliseconds specified in its parameter.
5980: **
5981: ** If the operating system does not support sleep requests with
5982: ** millisecond time resolution, then the time will be rounded up to
5983: ** the nearest second. The number of milliseconds of sleep actually
5984: ** requested from the operating system is returned.
5985: **
5986: ** ^SQLite implements this interface by calling the xSleep()
5987: ** method of the default [sqlite3_vfs] object. If the xSleep() method
5988: ** of the default VFS is not implemented correctly, or not implemented at
5989: ** all, then the behavior of sqlite3_sleep() may deviate from the description
5990: ** in the previous paragraphs.
5991: */
5992: SQLITE_API int sqlite3_sleep(int);
5993:
5994: /*
5995: ** CAPI3REF: Name Of The Folder Holding Temporary Files
5996: **
5997: ** ^(If this global variable is made to point to a string which is
5998: ** the name of a folder (a.k.a. directory), then all temporary files
5999: ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6000: ** will be placed in that directory.)^ ^If this variable
6001: ** is a NULL pointer, then SQLite performs a search for an appropriate
6002: ** temporary file directory.
6003: **
1.4 misho 6004: ** Applications are strongly discouraged from using this global variable.
6005: ** It is required to set a temporary folder on Windows Runtime (WinRT).
6006: ** But for all other platforms, it is highly recommended that applications
6007: ** neither read nor write this variable. This global variable is a relic
6008: ** that exists for backwards compatibility of legacy applications and should
6009: ** be avoided in new projects.
6010: **
1.2 misho 6011: ** It is not safe to read or modify this variable in more than one
6012: ** thread at a time. It is not safe to read or modify this variable
6013: ** if a [database connection] is being used at the same time in a separate
6014: ** thread.
6015: ** It is intended that this variable be set once
6016: ** as part of process initialization and before any SQLite interface
6017: ** routines have been called and that this variable remain unchanged
6018: ** thereafter.
6019: **
6020: ** ^The [temp_store_directory pragma] may modify this variable and cause
6021: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6022: ** the [temp_store_directory pragma] always assumes that any string
1.5 misho 6023: ** that this variable points to is held in memory obtained from
1.2 misho 6024: ** [sqlite3_malloc] and the pragma may attempt to free that memory
6025: ** using [sqlite3_free].
6026: ** Hence, if this variable is modified directly, either it should be
6027: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6028: ** or else the use of the [temp_store_directory pragma] should be avoided.
1.4 misho 6029: ** Except when requested by the [temp_store_directory pragma], SQLite
6030: ** does not free the memory that sqlite3_temp_directory points to. If
6031: ** the application wants that memory to be freed, it must do
6032: ** so itself, taking care to only do so after all [database connection]
6033: ** objects have been destroyed.
1.3 misho 6034: **
6035: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6036: ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6037: ** features that require the use of temporary files may fail. Here is an
6038: ** example of how to do this using C++ with the Windows Runtime:
6039: **
6040: ** <blockquote><pre>
6041: ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6042: ** TemporaryFolder->Path->Data();
6043: ** char zPathBuf[MAX_PATH + 1];
6044: ** memset(zPathBuf, 0, sizeof(zPathBuf));
6045: ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6046: ** NULL, NULL);
6047: ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6048: ** </pre></blockquote>
1.2 misho 6049: */
6050: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6051:
6052: /*
1.3 misho 6053: ** CAPI3REF: Name Of The Folder Holding Database Files
6054: **
6055: ** ^(If this global variable is made to point to a string which is
6056: ** the name of a folder (a.k.a. directory), then all database files
6057: ** specified with a relative pathname and created or accessed by
6058: ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6059: ** to be relative to that directory.)^ ^If this variable is a NULL
6060: ** pointer, then SQLite assumes that all database files specified
6061: ** with a relative pathname are relative to the current directory
6062: ** for the process. Only the windows VFS makes use of this global
6063: ** variable; it is ignored by the unix VFS.
6064: **
6065: ** Changing the value of this variable while a database connection is
6066: ** open can result in a corrupt database.
6067: **
6068: ** It is not safe to read or modify this variable in more than one
6069: ** thread at a time. It is not safe to read or modify this variable
6070: ** if a [database connection] is being used at the same time in a separate
6071: ** thread.
6072: ** It is intended that this variable be set once
6073: ** as part of process initialization and before any SQLite interface
6074: ** routines have been called and that this variable remain unchanged
6075: ** thereafter.
6076: **
6077: ** ^The [data_store_directory pragma] may modify this variable and cause
6078: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6079: ** the [data_store_directory pragma] always assumes that any string
1.5 misho 6080: ** that this variable points to is held in memory obtained from
1.3 misho 6081: ** [sqlite3_malloc] and the pragma may attempt to free that memory
6082: ** using [sqlite3_free].
6083: ** Hence, if this variable is modified directly, either it should be
6084: ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6085: ** or else the use of the [data_store_directory pragma] should be avoided.
6086: */
6087: SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6088:
6089: /*
1.5 misho 6090: ** CAPI3REF: Win32 Specific Interface
6091: **
6092: ** These interfaces are available only on Windows. The
6093: ** [sqlite3_win32_set_directory] interface is used to set the value associated
6094: ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6095: ** zValue, depending on the value of the type parameter. The zValue parameter
6096: ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6097: ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6098: ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6099: ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6100: ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6101: ** [sqlite3_data_directory] variable is intended to act as a replacement for
6102: ** the current directory on the sub-platforms of Win32 where that concept is
6103: ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6104: ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6105: ** sqlite3_win32_set_directory interface except the string parameter must be
6106: ** UTF-8 or UTF-16, respectively.
6107: */
6108: SQLITE_API int sqlite3_win32_set_directory(
6109: unsigned long type, /* Identifier for directory being set or reset */
6110: void *zValue /* New value for directory being set or reset */
6111: );
6112: SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6113: SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6114:
6115: /*
6116: ** CAPI3REF: Win32 Directory Types
6117: **
6118: ** These macros are only available on Windows. They define the allowed values
6119: ** for the type argument to the [sqlite3_win32_set_directory] interface.
6120: */
6121: #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6122: #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6123:
6124: /*
1.2 misho 6125: ** CAPI3REF: Test For Auto-Commit Mode
6126: ** KEYWORDS: {autocommit mode}
1.4 misho 6127: ** METHOD: sqlite3
1.2 misho 6128: **
6129: ** ^The sqlite3_get_autocommit() interface returns non-zero or
6130: ** zero if the given database connection is or is not in autocommit mode,
6131: ** respectively. ^Autocommit mode is on by default.
6132: ** ^Autocommit mode is disabled by a [BEGIN] statement.
6133: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6134: **
6135: ** If certain kinds of errors occur on a statement within a multi-statement
6136: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6137: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6138: ** transaction might be rolled back automatically. The only way to
6139: ** find out whether SQLite automatically rolled back the transaction after
6140: ** an error is to use this function.
6141: **
6142: ** If another thread changes the autocommit status of the database
6143: ** connection while this routine is running, then the return value
6144: ** is undefined.
6145: */
6146: SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6147:
6148: /*
6149: ** CAPI3REF: Find The Database Handle Of A Prepared Statement
1.4 misho 6150: ** METHOD: sqlite3_stmt
1.2 misho 6151: **
6152: ** ^The sqlite3_db_handle interface returns the [database connection] handle
6153: ** to which a [prepared statement] belongs. ^The [database connection]
6154: ** returned by sqlite3_db_handle is the same [database connection]
6155: ** that was the first argument
6156: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6157: ** create the statement in the first place.
6158: */
6159: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6160:
6161: /*
6162: ** CAPI3REF: Return The Filename For A Database Connection
1.4 misho 6163: ** METHOD: sqlite3
1.2 misho 6164: **
1.5 misho 6165: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6166: ** associated with database N of connection D.
6167: ** ^If there is no attached database N on the database
1.2 misho 6168: ** connection D, or if database N is a temporary or in-memory database, then
1.5 misho 6169: ** this function will return either a NULL pointer or an empty string.
6170: **
6171: ** ^The string value returned by this routine is owned and managed by
6172: ** the database connection. ^The value will be valid until the database N
6173: ** is [DETACH]-ed or until the database connection closes.
1.2 misho 6174: **
6175: ** ^The filename returned by this function is the output of the
6176: ** xFullPathname method of the [VFS]. ^In other words, the filename
6177: ** will be an absolute pathname, even if the filename used
6178: ** to open the database originally was a URI or relative pathname.
1.5 misho 6179: **
6180: ** If the filename pointer returned by this routine is not NULL, then it
6181: ** can be used as the filename input parameter to these routines:
6182: ** <ul>
6183: ** <li> [sqlite3_uri_parameter()]
6184: ** <li> [sqlite3_uri_boolean()]
6185: ** <li> [sqlite3_uri_int64()]
6186: ** <li> [sqlite3_filename_database()]
6187: ** <li> [sqlite3_filename_journal()]
6188: ** <li> [sqlite3_filename_wal()]
6189: ** </ul>
1.2 misho 6190: */
6191: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6192:
6193: /*
1.3 misho 6194: ** CAPI3REF: Determine if a database is read-only
1.4 misho 6195: ** METHOD: sqlite3
1.3 misho 6196: **
6197: ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6198: ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6199: ** the name of a database on connection D.
6200: */
6201: SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6202:
6203: /*
1.6 ! misho 6204: ** CAPI3REF: Determine the transaction state of a database
! 6205: ** METHOD: sqlite3
! 6206: **
! 6207: ** ^The sqlite3_txn_state(D,S) interface returns the current
! 6208: ** [transaction state] of schema S in database connection D. ^If S is NULL,
! 6209: ** then the highest transaction state of any schema on database connection D
! 6210: ** is returned. Transaction states are (in order of lowest to highest):
! 6211: ** <ol>
! 6212: ** <li value="0"> SQLITE_TXN_NONE
! 6213: ** <li value="1"> SQLITE_TXN_READ
! 6214: ** <li value="2"> SQLITE_TXN_WRITE
! 6215: ** </ol>
! 6216: ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
! 6217: ** a valid schema, then -1 is returned.
! 6218: */
! 6219: SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
! 6220:
! 6221: /*
! 6222: ** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
! 6223: ** KEYWORDS: {transaction state}
! 6224: **
! 6225: ** These constants define the current transaction state of a database file.
! 6226: ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
! 6227: ** constants in order to describe the transaction state of schema S
! 6228: ** in [database connection] D.
! 6229: **
! 6230: ** <dl>
! 6231: ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
! 6232: ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
! 6233: ** pending.</dd>
! 6234: **
! 6235: ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
! 6236: ** <dd>The SQLITE_TXN_READ state means that the database is currently
! 6237: ** in a read transaction. Content has been read from the database file
! 6238: ** but nothing in the database file has changed. The transaction state
! 6239: ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
! 6240: ** no other conflicting concurrent write transactions. The transaction
! 6241: ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
! 6242: ** [COMMIT].</dd>
! 6243: **
! 6244: ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
! 6245: ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
! 6246: ** in a write transaction. Content has been written to the database file
! 6247: ** but has not yet committed. The transaction state will change to
! 6248: ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
! 6249: */
! 6250: #define SQLITE_TXN_NONE 0
! 6251: #define SQLITE_TXN_READ 1
! 6252: #define SQLITE_TXN_WRITE 2
! 6253:
! 6254: /*
1.2 misho 6255: ** CAPI3REF: Find the next prepared statement
1.4 misho 6256: ** METHOD: sqlite3
1.2 misho 6257: **
6258: ** ^This interface returns a pointer to the next [prepared statement] after
6259: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6260: ** then this interface returns a pointer to the first prepared statement
6261: ** associated with the database connection pDb. ^If no prepared statement
6262: ** satisfies the conditions of this routine, it returns NULL.
6263: **
6264: ** The [database connection] pointer D in a call to
6265: ** [sqlite3_next_stmt(D,S)] must refer to an open database
6266: ** connection and in particular must not be a NULL pointer.
6267: */
6268: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6269:
6270: /*
6271: ** CAPI3REF: Commit And Rollback Notification Callbacks
1.4 misho 6272: ** METHOD: sqlite3
1.2 misho 6273: **
6274: ** ^The sqlite3_commit_hook() interface registers a callback
6275: ** function to be invoked whenever a transaction is [COMMIT | committed].
6276: ** ^Any callback set by a previous call to sqlite3_commit_hook()
6277: ** for the same database connection is overridden.
6278: ** ^The sqlite3_rollback_hook() interface registers a callback
6279: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6280: ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6281: ** for the same database connection is overridden.
6282: ** ^The pArg argument is passed through to the callback.
6283: ** ^If the callback on a commit hook function returns non-zero,
6284: ** then the commit is converted into a rollback.
6285: **
6286: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6287: ** return the P argument from the previous call of the same function
6288: ** on the same [database connection] D, or NULL for
6289: ** the first call for each function on D.
6290: **
6291: ** The commit and rollback hook callbacks are not reentrant.
6292: ** The callback implementation must not do anything that will modify
6293: ** the database connection that invoked the callback. Any actions
6294: ** to modify the database connection must be deferred until after the
6295: ** completion of the [sqlite3_step()] call that triggered the commit
6296: ** or rollback hook in the first place.
6297: ** Note that running any other SQL statements, including SELECT statements,
6298: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6299: ** the database connections for the meaning of "modify" in this paragraph.
6300: **
6301: ** ^Registering a NULL function disables the callback.
6302: **
6303: ** ^When the commit hook callback routine returns zero, the [COMMIT]
6304: ** operation is allowed to continue normally. ^If the commit hook
6305: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6306: ** ^The rollback hook is invoked on a rollback that results from a commit
6307: ** hook returning non-zero, just as it would be with any other rollback.
6308: **
6309: ** ^For the purposes of this API, a transaction is said to have been
6310: ** rolled back if an explicit "ROLLBACK" statement is executed, or
6311: ** an error or constraint causes an implicit rollback to occur.
6312: ** ^The rollback callback is not invoked if a transaction is
6313: ** automatically rolled back because the database connection is closed.
6314: **
6315: ** See also the [sqlite3_update_hook()] interface.
6316: */
6317: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6318: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6319:
6320: /*
6321: ** CAPI3REF: Data Change Notification Callbacks
1.4 misho 6322: ** METHOD: sqlite3
1.2 misho 6323: **
6324: ** ^The sqlite3_update_hook() interface registers a callback function
6325: ** with the [database connection] identified by the first argument
1.4 misho 6326: ** to be invoked whenever a row is updated, inserted or deleted in
6327: ** a [rowid table].
1.2 misho 6328: ** ^Any callback set by a previous call to this function
6329: ** for the same database connection is overridden.
6330: **
6331: ** ^The second argument is a pointer to the function to invoke when a
1.4 misho 6332: ** row is updated, inserted or deleted in a rowid table.
1.2 misho 6333: ** ^The first argument to the callback is a copy of the third argument
6334: ** to sqlite3_update_hook().
6335: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6336: ** or [SQLITE_UPDATE], depending on the operation that caused the callback
6337: ** to be invoked.
6338: ** ^The third and fourth arguments to the callback contain pointers to the
6339: ** database and table name containing the affected row.
6340: ** ^The final callback parameter is the [rowid] of the row.
6341: ** ^In the case of an update, this is the [rowid] after the update takes place.
6342: **
6343: ** ^(The update hook is not invoked when internal system tables are
1.5 misho 6344: ** modified (i.e. sqlite_sequence).)^
1.4 misho 6345: ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
1.2 misho 6346: **
6347: ** ^In the current implementation, the update hook
1.5 misho 6348: ** is not invoked when conflicting rows are deleted because of an
1.2 misho 6349: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6350: ** invoked when rows are deleted using the [truncate optimization].
6351: ** The exceptions defined in this paragraph might change in a future
6352: ** release of SQLite.
6353: **
6354: ** The update hook implementation must not do anything that will modify
6355: ** the database connection that invoked the update hook. Any actions
6356: ** to modify the database connection must be deferred until after the
6357: ** completion of the [sqlite3_step()] call that triggered the update hook.
6358: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6359: ** database connections for the meaning of "modify" in this paragraph.
6360: **
6361: ** ^The sqlite3_update_hook(D,C,P) function
6362: ** returns the P argument from the previous call
6363: ** on the same [database connection] D, or NULL for
6364: ** the first call on D.
6365: **
1.4 misho 6366: ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6367: ** and [sqlite3_preupdate_hook()] interfaces.
1.2 misho 6368: */
6369: SQLITE_API void *sqlite3_update_hook(
1.5 misho 6370: sqlite3*,
1.2 misho 6371: void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6372: void*
6373: );
6374:
6375: /*
6376: ** CAPI3REF: Enable Or Disable Shared Pager Cache
6377: **
6378: ** ^(This routine enables or disables the sharing of the database cache
6379: ** and schema data structures between [database connection | connections]
6380: ** to the same database. Sharing is enabled if the argument is true
6381: ** and disabled if the argument is false.)^
6382: **
6383: ** ^Cache sharing is enabled and disabled for an entire process.
1.5 misho 6384: ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6385: ** In prior versions of SQLite,
1.2 misho 6386: ** sharing was enabled or disabled for each thread separately.
6387: **
6388: ** ^(The cache sharing mode set by this interface effects all subsequent
6389: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
1.5 misho 6390: ** Existing database connections continue to use the sharing mode
1.2 misho 6391: ** that was in effect at the time they were opened.)^
6392: **
6393: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6394: ** successfully. An [error code] is returned otherwise.)^
6395: **
1.5 misho 6396: ** ^Shared cache is disabled by default. It is recommended that it stay
6397: ** that way. In other words, do not use this routine. This interface
6398: ** continues to be provided for historical compatibility, but its use is
6399: ** discouraged. Any use of shared cache is discouraged. If shared cache
6400: ** must be used, it is recommended that shared cache only be enabled for
6401: ** individual database connections using the [sqlite3_open_v2()] interface
6402: ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
1.2 misho 6403: **
1.4 misho 6404: ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
1.5 misho 6405: ** and will always return SQLITE_MISUSE. On those systems,
6406: ** shared cache mode should be enabled per-database connection via
1.4 misho 6407: ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6408: **
1.3 misho 6409: ** This interface is threadsafe on processors where writing a
6410: ** 32-bit integer is atomic.
6411: **
1.2 misho 6412: ** See Also: [SQLite Shared-Cache Mode]
6413: */
6414: SQLITE_API int sqlite3_enable_shared_cache(int);
6415:
6416: /*
6417: ** CAPI3REF: Attempt To Free Heap Memory
6418: **
6419: ** ^The sqlite3_release_memory() interface attempts to free N bytes
6420: ** of heap memory by deallocating non-essential memory allocations
6421: ** held by the database library. Memory used to cache database
6422: ** pages to improve performance is an example of non-essential memory.
6423: ** ^sqlite3_release_memory() returns the number of bytes actually freed,
6424: ** which might be more or less than the amount requested.
6425: ** ^The sqlite3_release_memory() routine is a no-op returning zero
6426: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6427: **
6428: ** See also: [sqlite3_db_release_memory()]
6429: */
6430: SQLITE_API int sqlite3_release_memory(int);
6431:
6432: /*
6433: ** CAPI3REF: Free Memory Used By A Database Connection
1.4 misho 6434: ** METHOD: sqlite3
1.2 misho 6435: **
6436: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6437: ** memory as possible from database connection D. Unlike the
1.4 misho 6438: ** [sqlite3_release_memory()] interface, this interface is in effect even
6439: ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
1.2 misho 6440: ** omitted.
6441: **
6442: ** See also: [sqlite3_release_memory()]
6443: */
6444: SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6445:
6446: /*
6447: ** CAPI3REF: Impose A Limit On Heap Size
6448: **
1.5 misho 6449: ** These interfaces impose limits on the amount of heap memory that will be
6450: ** by all database connections within a single process.
6451: **
1.2 misho 6452: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6453: ** soft limit on the amount of heap memory that may be allocated by SQLite.
6454: ** ^SQLite strives to keep heap memory utilization below the soft heap
6455: ** limit by reducing the number of pages held in the page cache
6456: ** as heap memory usages approaches the limit.
6457: ** ^The soft heap limit is "soft" because even though SQLite strives to stay
6458: ** below the limit, it will exceed the limit rather than generate
1.5 misho 6459: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
1.2 misho 6460: ** is advisory only.
6461: **
1.5 misho 6462: ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6463: ** N bytes on the amount of memory that will be allocated. ^The
6464: ** sqlite3_hard_heap_limit64(N) interface is similar to
6465: ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6466: ** when the hard heap limit is reached.
6467: **
6468: ** ^The return value from both sqlite3_soft_heap_limit64() and
6469: ** sqlite3_hard_heap_limit64() is the size of
6470: ** the heap limit prior to the call, or negative in the case of an
1.2 misho 6471: ** error. ^If the argument N is negative
1.5 misho 6472: ** then no change is made to the heap limit. Hence, the current
6473: ** size of heap limits can be determined by invoking
6474: ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6475: **
6476: ** ^Setting the heap limits to zero disables the heap limiter mechanism.
6477: **
6478: ** ^The soft heap limit may not be greater than the hard heap limit.
6479: ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6480: ** is invoked with a value of N that is greater than the hard heap limit,
6481: ** the the soft heap limit is set to the value of the hard heap limit.
6482: ** ^The soft heap limit is automatically enabled whenever the hard heap
6483: ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6484: ** the soft heap limit is outside the range of 1..N, then the soft heap
6485: ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6486: ** hard heap limit is enabled makes the soft heap limit equal to the
6487: ** hard heap limit.
1.2 misho 6488: **
1.5 misho 6489: ** The memory allocation limits can also be adjusted using
6490: ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
1.2 misho 6491: **
1.5 misho 6492: ** ^(The heap limits are not enforced in the current implementation
1.2 misho 6493: ** if one or more of following conditions are true:
6494: **
6495: ** <ul>
1.5 misho 6496: ** <li> The limit value is set to zero.
1.2 misho 6497: ** <li> Memory accounting is disabled using a combination of the
6498: ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6499: ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6500: ** <li> An alternative page cache implementation is specified using
6501: ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6502: ** <li> The page cache allocates from its own memory pool supplied
6503: ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6504: ** from the heap.
6505: ** </ul>)^
6506: **
1.5 misho 6507: ** The circumstances under which SQLite will enforce the heap limits may
1.2 misho 6508: ** changes in future releases of SQLite.
6509: */
6510: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
1.5 misho 6511: SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
1.2 misho 6512:
6513: /*
6514: ** CAPI3REF: Deprecated Soft Heap Limit Interface
6515: ** DEPRECATED
6516: **
6517: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6518: ** interface. This routine is provided for historical compatibility
6519: ** only. All new applications should use the
6520: ** [sqlite3_soft_heap_limit64()] interface rather than this one.
6521: */
6522: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6523:
6524:
6525: /*
6526: ** CAPI3REF: Extract Metadata About A Column Of A Table
1.4 misho 6527: ** METHOD: sqlite3
1.2 misho 6528: **
1.4 misho 6529: ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6530: ** information about column C of table T in database D
6531: ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6532: ** interface returns SQLITE_OK and fills in the non-NULL pointers in
6533: ** the final five arguments with appropriate values if the specified
6534: ** column exists. ^The sqlite3_table_column_metadata() interface returns
1.5 misho 6535: ** SQLITE_ERROR if the specified column does not exist.
1.4 misho 6536: ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6537: ** NULL pointer, then this routine simply checks for the existence of the
6538: ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
1.5 misho 6539: ** does not. If the table name parameter T in a call to
6540: ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6541: ** undefined behavior.
1.2 misho 6542: **
6543: ** ^The column is identified by the second, third and fourth parameters to
1.4 misho 6544: ** this function. ^(The second parameter is either the name of the database
1.2 misho 6545: ** (i.e. "main", "temp", or an attached database) containing the specified
1.4 misho 6546: ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
1.2 misho 6547: ** for the table using the same algorithm used by the database engine to
6548: ** resolve unqualified table references.
6549: **
6550: ** ^The third and fourth parameters to this function are the table and column
1.4 misho 6551: ** name of the desired column, respectively.
1.2 misho 6552: **
6553: ** ^Metadata is returned by writing to the memory locations passed as the 5th
6554: ** and subsequent parameters to this function. ^Any of these arguments may be
6555: ** NULL, in which case the corresponding element of metadata is omitted.
6556: **
6557: ** ^(<blockquote>
6558: ** <table border="1">
6559: ** <tr><th> Parameter <th> Output<br>Type <th> Description
6560: **
6561: ** <tr><td> 5th <td> const char* <td> Data type
6562: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6563: ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6564: ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6565: ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6566: ** </table>
6567: ** </blockquote>)^
6568: **
6569: ** ^The memory pointed to by the character pointers returned for the
1.4 misho 6570: ** declaration type and collation sequence is valid until the next
1.2 misho 6571: ** call to any SQLite API function.
6572: **
6573: ** ^If the specified table is actually a view, an [error code] is returned.
6574: **
1.5 misho 6575: ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
1.4 misho 6576: ** is not a [WITHOUT ROWID] table and an
1.2 misho 6577: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6578: ** parameters are set for the explicitly declared column. ^(If there is no
1.4 misho 6579: ** [INTEGER PRIMARY KEY] column, then the outputs
6580: ** for the [rowid] are set as follows:
1.2 misho 6581: **
6582: ** <pre>
6583: ** data type: "INTEGER"
6584: ** collation sequence: "BINARY"
6585: ** not null: 0
6586: ** primary key: 1
6587: ** auto increment: 0
6588: ** </pre>)^
6589: **
1.4 misho 6590: ** ^This function causes all database schemas to be read from disk and
6591: ** parsed, if that has not already been done, and returns an error if
6592: ** any errors are encountered while loading the schema.
1.2 misho 6593: */
6594: SQLITE_API int sqlite3_table_column_metadata(
6595: sqlite3 *db, /* Connection handle */
6596: const char *zDbName, /* Database name or NULL */
6597: const char *zTableName, /* Table name */
6598: const char *zColumnName, /* Column name */
6599: char const **pzDataType, /* OUTPUT: Declared data type */
6600: char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6601: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6602: int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6603: int *pAutoinc /* OUTPUT: True if column is auto-increment */
6604: );
6605:
6606: /*
6607: ** CAPI3REF: Load An Extension
1.4 misho 6608: ** METHOD: sqlite3
1.2 misho 6609: **
6610: ** ^This interface loads an SQLite extension library from the named file.
6611: **
6612: ** ^The sqlite3_load_extension() interface attempts to load an
1.4 misho 6613: ** [SQLite extension] library contained in the file zFile. If
6614: ** the file cannot be loaded directly, attempts are made to load
6615: ** with various operating-system specific extensions added.
6616: ** So for example, if "samplelib" cannot be loaded, then names like
6617: ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6618: ** be tried also.
1.2 misho 6619: **
6620: ** ^The entry point is zProc.
1.4 misho 6621: ** ^(zProc may be 0, in which case SQLite will try to come up with an
6622: ** entry point name on its own. It first tries "sqlite3_extension_init".
6623: ** If that does not work, it constructs a name "sqlite3_X_init" where the
6624: ** X is consists of the lower-case equivalent of all ASCII alphabetic
6625: ** characters in the filename from the last "/" to the first following
6626: ** "." and omitting any initial "lib".)^
1.2 misho 6627: ** ^The sqlite3_load_extension() interface returns
6628: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6629: ** ^If an error occurs and pzErrMsg is not 0, then the
6630: ** [sqlite3_load_extension()] interface shall attempt to
6631: ** fill *pzErrMsg with error message text stored in memory
6632: ** obtained from [sqlite3_malloc()]. The calling function
6633: ** should free this memory by calling [sqlite3_free()].
6634: **
6635: ** ^Extension loading must be enabled using
1.4 misho 6636: ** [sqlite3_enable_load_extension()] or
6637: ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6638: ** prior to calling this API,
1.2 misho 6639: ** otherwise an error will be returned.
6640: **
1.5 misho 6641: ** <b>Security warning:</b> It is recommended that the
1.4 misho 6642: ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6643: ** interface. The use of the [sqlite3_enable_load_extension()] interface
6644: ** should be avoided. This will keep the SQL function [load_extension()]
6645: ** disabled and prevent SQL injections from giving attackers
6646: ** access to extension loading capabilities.
6647: **
1.2 misho 6648: ** See also the [load_extension() SQL function].
6649: */
6650: SQLITE_API int sqlite3_load_extension(
6651: sqlite3 *db, /* Load the extension into this database connection */
6652: const char *zFile, /* Name of the shared library containing extension */
6653: const char *zProc, /* Entry point. Derived from zFile if 0 */
6654: char **pzErrMsg /* Put error message here if not 0 */
6655: );
6656:
6657: /*
6658: ** CAPI3REF: Enable Or Disable Extension Loading
1.4 misho 6659: ** METHOD: sqlite3
1.2 misho 6660: **
6661: ** ^So as not to open security holes in older applications that are
1.4 misho 6662: ** unprepared to deal with [extension loading], and as a means of disabling
6663: ** [extension loading] while evaluating user-entered SQL, the following API
1.2 misho 6664: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6665: **
1.4 misho 6666: ** ^Extension loading is off by default.
1.2 misho 6667: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6668: ** to turn extension loading on and call it with onoff==0 to turn
6669: ** it back off again.
1.4 misho 6670: **
6671: ** ^This interface enables or disables both the C-API
6672: ** [sqlite3_load_extension()] and the SQL function [load_extension()].
6673: ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6674: ** to enable or disable only the C-API.)^
6675: **
6676: ** <b>Security warning:</b> It is recommended that extension loading
1.5 misho 6677: ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
1.4 misho 6678: ** rather than this interface, so the [load_extension()] SQL function
6679: ** remains disabled. This will prevent SQL injections from giving attackers
6680: ** access to extension loading capabilities.
1.2 misho 6681: */
6682: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6683:
6684: /*
6685: ** CAPI3REF: Automatically Load Statically Linked Extensions
6686: **
6687: ** ^This interface causes the xEntryPoint() function to be invoked for
6688: ** each new [database connection] that is created. The idea here is that
1.4 misho 6689: ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
1.2 misho 6690: ** that is to be automatically loaded into all new database connections.
6691: **
6692: ** ^(Even though the function prototype shows that xEntryPoint() takes
6693: ** no arguments and returns void, SQLite invokes xEntryPoint() with three
1.4 misho 6694: ** arguments and expects an integer result as if the signature of the
1.2 misho 6695: ** entry point where as follows:
6696: **
6697: ** <blockquote><pre>
6698: ** int xEntryPoint(
6699: ** sqlite3 *db,
6700: ** const char **pzErrMsg,
6701: ** const struct sqlite3_api_routines *pThunk
6702: ** );
6703: ** </pre></blockquote>)^
6704: **
6705: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6706: ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6707: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6708: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6709: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6710: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6711: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6712: **
6713: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6714: ** on the list of automatic extensions is a harmless no-op. ^No entry point
6715: ** will be called more than once for each database connection that is opened.
6716: **
1.4 misho 6717: ** See also: [sqlite3_reset_auto_extension()]
6718: ** and [sqlite3_cancel_auto_extension()]
1.2 misho 6719: */
1.4 misho 6720: SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6721:
6722: /*
6723: ** CAPI3REF: Cancel Automatic Extension Loading
6724: **
6725: ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6726: ** initialization routine X that was registered using a prior call to
6727: ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
1.5 misho 6728: ** routine returns 1 if initialization routine X was successfully
1.4 misho 6729: ** unregistered and it returns 0 if X was not on the list of initialization
6730: ** routines.
6731: */
6732: SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
1.2 misho 6733:
6734: /*
6735: ** CAPI3REF: Reset Automatic Extension Loading
6736: **
6737: ** ^This interface disables all automatic extensions previously
6738: ** registered using [sqlite3_auto_extension()].
6739: */
6740: SQLITE_API void sqlite3_reset_auto_extension(void);
6741:
6742: /*
6743: ** The interface to the virtual-table mechanism is currently considered
6744: ** to be experimental. The interface might change in incompatible ways.
6745: ** If this is a problem for you, do not use the interface at this time.
6746: **
6747: ** When the virtual-table mechanism stabilizes, we will declare the
6748: ** interface fixed, support it indefinitely, and remove this comment.
6749: */
6750:
6751: /*
6752: ** Structures used by the virtual table interface
6753: */
6754: typedef struct sqlite3_vtab sqlite3_vtab;
6755: typedef struct sqlite3_index_info sqlite3_index_info;
6756: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6757: typedef struct sqlite3_module sqlite3_module;
6758:
6759: /*
6760: ** CAPI3REF: Virtual Table Object
6761: ** KEYWORDS: sqlite3_module {virtual table module}
6762: **
1.5 misho 6763: ** This structure, sometimes called a "virtual table module",
6764: ** defines the implementation of a [virtual table].
1.2 misho 6765: ** This structure consists mostly of methods for the module.
6766: **
6767: ** ^A virtual table module is created by filling in a persistent
6768: ** instance of this structure and passing a pointer to that instance
6769: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6770: ** ^The registration remains valid until it is replaced by a different
6771: ** module or until the [database connection] closes. The content
6772: ** of this structure must not change while it is registered with
6773: ** any database connection.
6774: */
6775: struct sqlite3_module {
6776: int iVersion;
6777: int (*xCreate)(sqlite3*, void *pAux,
6778: int argc, const char *const*argv,
6779: sqlite3_vtab **ppVTab, char**);
6780: int (*xConnect)(sqlite3*, void *pAux,
6781: int argc, const char *const*argv,
6782: sqlite3_vtab **ppVTab, char**);
6783: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6784: int (*xDisconnect)(sqlite3_vtab *pVTab);
6785: int (*xDestroy)(sqlite3_vtab *pVTab);
6786: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6787: int (*xClose)(sqlite3_vtab_cursor*);
6788: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6789: int argc, sqlite3_value **argv);
6790: int (*xNext)(sqlite3_vtab_cursor*);
6791: int (*xEof)(sqlite3_vtab_cursor*);
6792: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6793: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6794: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6795: int (*xBegin)(sqlite3_vtab *pVTab);
6796: int (*xSync)(sqlite3_vtab *pVTab);
6797: int (*xCommit)(sqlite3_vtab *pVTab);
6798: int (*xRollback)(sqlite3_vtab *pVTab);
6799: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6800: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6801: void **ppArg);
6802: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
1.5 misho 6803: /* The methods above are in version 1 of the sqlite_module object. Those
1.2 misho 6804: ** below are for version 2 and greater. */
6805: int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6806: int (*xRelease)(sqlite3_vtab *pVTab, int);
6807: int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
1.5 misho 6808: /* The methods above are in versions 1 and 2 of the sqlite_module object.
6809: ** Those below are for version 3 and greater. */
6810: int (*xShadowName)(const char*);
1.2 misho 6811: };
6812:
6813: /*
6814: ** CAPI3REF: Virtual Table Indexing Information
6815: ** KEYWORDS: sqlite3_index_info
6816: **
6817: ** The sqlite3_index_info structure and its substructures is used as part
6818: ** of the [virtual table] interface to
6819: ** pass information into and receive the reply from the [xBestIndex]
6820: ** method of a [virtual table module]. The fields under **Inputs** are the
6821: ** inputs to xBestIndex and are read-only. xBestIndex inserts its
6822: ** results into the **Outputs** fields.
6823: **
6824: ** ^(The aConstraint[] array records WHERE clause constraints of the form:
6825: **
6826: ** <blockquote>column OP expr</blockquote>
6827: **
6828: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
6829: ** stored in aConstraint[].op using one of the
6830: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6831: ** ^(The index of the column is stored in
6832: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6833: ** expr on the right-hand side can be evaluated (and thus the constraint
6834: ** is usable) and false if it cannot.)^
6835: **
6836: ** ^The optimizer automatically inverts terms of the form "expr OP column"
6837: ** and makes other simplifications to the WHERE clause in an attempt to
6838: ** get as many WHERE clause terms into the form shown above as possible.
6839: ** ^The aConstraint[] array only reports WHERE clause terms that are
6840: ** relevant to the particular virtual table being queried.
6841: **
6842: ** ^Information about the ORDER BY clause is stored in aOrderBy[].
6843: ** ^Each term of aOrderBy records a column of the ORDER BY clause.
6844: **
1.4 misho 6845: ** The colUsed field indicates which columns of the virtual table may be
6846: ** required by the current scan. Virtual table columns are numbered from
6847: ** zero in the order in which they appear within the CREATE TABLE statement
6848: ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6849: ** the corresponding bit is set within the colUsed mask if the column may be
6850: ** required by SQLite. If the table has at least 64 columns and any column
6851: ** to the right of the first 63 is required, then bit 63 of colUsed is also
6852: ** set. In other words, column iCol may be required if the expression
1.5 misho 6853: ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
1.4 misho 6854: ** non-zero.
6855: **
1.2 misho 6856: ** The [xBestIndex] method must fill aConstraintUsage[] with information
6857: ** about what parameters to pass to xFilter. ^If argvIndex>0 then
6858: ** the right-hand side of the corresponding aConstraint[] is evaluated
6859: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6860: ** is true, then the constraint is assumed to be fully handled by the
1.5 misho 6861: ** virtual table and might not be checked again by the byte code.)^ ^(The
6862: ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
6863: ** is left in its default setting of false, the constraint will always be
6864: ** checked separately in byte code. If the omit flag is change to true, then
6865: ** the constraint may or may not be checked in byte code. In other words,
6866: ** when the omit flag is true there is no guarantee that the constraint will
6867: ** not be checked again using byte code.)^
1.2 misho 6868: **
6869: ** ^The idxNum and idxPtr values are recorded and passed into the
6870: ** [xFilter] method.
6871: ** ^[sqlite3_free()] is used to free idxPtr if and only if
6872: ** needToFreeIdxPtr is true.
6873: **
6874: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6875: ** the correct order to satisfy the ORDER BY clause so that no separate
6876: ** sorting step is required.
6877: **
1.4 misho 6878: ** ^The estimatedCost value is an estimate of the cost of a particular
6879: ** strategy. A cost of N indicates that the cost of the strategy is similar
1.5 misho 6880: ** to a linear scan of an SQLite table with N rows. A cost of log(N)
1.4 misho 6881: ** indicates that the expense of the operation is similar to that of a
6882: ** binary search on a unique indexed field of an SQLite table with N rows.
6883: **
6884: ** ^The estimatedRows value is an estimate of the number of rows that
6885: ** will be returned by the strategy.
6886: **
1.5 misho 6887: ** The xBestIndex method may optionally populate the idxFlags field with a
1.4 misho 6888: ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6889: ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
1.5 misho 6890: ** assumes that the strategy may visit at most one row.
1.4 misho 6891: **
6892: ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6893: ** SQLite also assumes that if a call to the xUpdate() method is made as
6894: ** part of the same statement to delete or update a virtual table row and the
6895: ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6896: ** any database changes. In other words, if the xUpdate() returns
6897: ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6898: ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6899: ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6900: ** the xUpdate method are automatically rolled back by SQLite.
6901: **
6902: ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
1.5 misho 6903: ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6904: ** If a virtual table extension is
6905: ** used with an SQLite version earlier than 3.8.2, the results of attempting
6906: ** to read or write the estimatedRows field are undefined (but are likely
6907: ** to include crashing the application). The estimatedRows field should
1.4 misho 6908: ** therefore only be used if [sqlite3_libversion_number()] returns a
6909: ** value greater than or equal to 3008002. Similarly, the idxFlags field
1.5 misho 6910: ** was added for [version 3.9.0] ([dateof:3.9.0]).
6911: ** It may therefore only be used if
1.4 misho 6912: ** sqlite3_libversion_number() returns a value greater than or equal to
6913: ** 3009000.
1.2 misho 6914: */
6915: struct sqlite3_index_info {
6916: /* Inputs */
6917: int nConstraint; /* Number of entries in aConstraint */
6918: struct sqlite3_index_constraint {
1.4 misho 6919: int iColumn; /* Column constrained. -1 for ROWID */
1.2 misho 6920: unsigned char op; /* Constraint operator */
6921: unsigned char usable; /* True if this constraint is usable */
6922: int iTermOffset; /* Used internally - xBestIndex should ignore */
6923: } *aConstraint; /* Table of WHERE clause constraints */
6924: int nOrderBy; /* Number of terms in the ORDER BY clause */
6925: struct sqlite3_index_orderby {
6926: int iColumn; /* Column number */
6927: unsigned char desc; /* True for DESC. False for ASC. */
6928: } *aOrderBy; /* The ORDER BY clause */
6929: /* Outputs */
6930: struct sqlite3_index_constraint_usage {
6931: int argvIndex; /* if >0, constraint is part of argv to xFilter */
6932: unsigned char omit; /* Do not code a test for this constraint */
6933: } *aConstraintUsage;
6934: int idxNum; /* Number used to identify the index */
6935: char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6936: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6937: int orderByConsumed; /* True if output is already ordered */
1.4 misho 6938: double estimatedCost; /* Estimated cost of using this index */
6939: /* Fields below are only available in SQLite 3.8.2 and later */
6940: sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6941: /* Fields below are only available in SQLite 3.9.0 and later */
6942: int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6943: /* Fields below are only available in SQLite 3.10.0 and later */
6944: sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
1.2 misho 6945: };
6946:
6947: /*
1.4 misho 6948: ** CAPI3REF: Virtual Table Scan Flags
1.5 misho 6949: **
6950: ** Virtual table implementations are allowed to set the
6951: ** [sqlite3_index_info].idxFlags field to some combination of
6952: ** these bits.
1.4 misho 6953: */
6954: #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6955:
6956: /*
1.2 misho 6957: ** CAPI3REF: Virtual Table Constraint Operator Codes
6958: **
1.5 misho 6959: ** These macros define the allowed values for the
1.2 misho 6960: ** [sqlite3_index_info].aConstraint[].op field. Each value represents
6961: ** an operator that is part of a constraint term in the wHERE clause of
6962: ** a query that uses a [virtual table].
6963: */
1.5 misho 6964: #define SQLITE_INDEX_CONSTRAINT_EQ 2
6965: #define SQLITE_INDEX_CONSTRAINT_GT 4
6966: #define SQLITE_INDEX_CONSTRAINT_LE 8
6967: #define SQLITE_INDEX_CONSTRAINT_LT 16
6968: #define SQLITE_INDEX_CONSTRAINT_GE 32
6969: #define SQLITE_INDEX_CONSTRAINT_MATCH 64
6970: #define SQLITE_INDEX_CONSTRAINT_LIKE 65
6971: #define SQLITE_INDEX_CONSTRAINT_GLOB 66
6972: #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6973: #define SQLITE_INDEX_CONSTRAINT_NE 68
6974: #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6975: #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6976: #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6977: #define SQLITE_INDEX_CONSTRAINT_IS 72
6978: #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
1.2 misho 6979:
6980: /*
6981: ** CAPI3REF: Register A Virtual Table Implementation
1.4 misho 6982: ** METHOD: sqlite3
1.2 misho 6983: **
6984: ** ^These routines are used to register a new [virtual table module] name.
6985: ** ^Module names must be registered before
6986: ** creating a new [virtual table] using the module and before using a
6987: ** preexisting [virtual table] for the module.
6988: **
6989: ** ^The module name is registered on the [database connection] specified
1.5 misho 6990: ** by the first parameter. ^The name of the module is given by the
1.2 misho 6991: ** second parameter. ^The third parameter is a pointer to
6992: ** the implementation of the [virtual table module]. ^The fourth
6993: ** parameter is an arbitrary client data pointer that is passed through
6994: ** into the [xCreate] and [xConnect] methods of the virtual table module
6995: ** when a new virtual table is be being created or reinitialized.
6996: **
6997: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6998: ** is a pointer to a destructor for the pClientData. ^SQLite will
6999: ** invoke the destructor function (if it is not NULL) when SQLite
7000: ** no longer needs the pClientData pointer. ^The destructor will also
7001: ** be invoked if the call to sqlite3_create_module_v2() fails.
7002: ** ^The sqlite3_create_module()
7003: ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7004: ** destructor.
1.5 misho 7005: **
7006: ** ^If the third parameter (the pointer to the sqlite3_module object) is
7007: ** NULL then no new module is create and any existing modules with the
7008: ** same name are dropped.
7009: **
7010: ** See also: [sqlite3_drop_modules()]
1.2 misho 7011: */
7012: SQLITE_API int sqlite3_create_module(
7013: sqlite3 *db, /* SQLite connection to register module with */
7014: const char *zName, /* Name of the module */
7015: const sqlite3_module *p, /* Methods for the module */
7016: void *pClientData /* Client data for xCreate/xConnect */
7017: );
7018: SQLITE_API int sqlite3_create_module_v2(
7019: sqlite3 *db, /* SQLite connection to register module with */
7020: const char *zName, /* Name of the module */
7021: const sqlite3_module *p, /* Methods for the module */
7022: void *pClientData, /* Client data for xCreate/xConnect */
7023: void(*xDestroy)(void*) /* Module destructor function */
7024: );
7025:
7026: /*
1.5 misho 7027: ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7028: ** METHOD: sqlite3
7029: **
7030: ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7031: ** table modules from database connection D except those named on list L.
7032: ** The L parameter must be either NULL or a pointer to an array of pointers
7033: ** to strings where the array is terminated by a single NULL pointer.
7034: ** ^If the L parameter is NULL, then all virtual table modules are removed.
7035: **
7036: ** See also: [sqlite3_create_module()]
7037: */
7038: SQLITE_API int sqlite3_drop_modules(
7039: sqlite3 *db, /* Remove modules from this connection */
7040: const char **azKeep /* Except, do not remove the ones named here */
7041: );
7042:
7043: /*
1.2 misho 7044: ** CAPI3REF: Virtual Table Instance Object
7045: ** KEYWORDS: sqlite3_vtab
7046: **
7047: ** Every [virtual table module] implementation uses a subclass
7048: ** of this object to describe a particular instance
7049: ** of the [virtual table]. Each subclass will
7050: ** be tailored to the specific needs of the module implementation.
7051: ** The purpose of this superclass is to define certain fields that are
7052: ** common to all module implementations.
7053: **
7054: ** ^Virtual tables methods can set an error message by assigning a
7055: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7056: ** take care that any prior string is freed by a call to [sqlite3_free()]
7057: ** prior to assigning a new string to zErrMsg. ^After the error message
7058: ** is delivered up to the client application, the string will be automatically
7059: ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7060: */
7061: struct sqlite3_vtab {
7062: const sqlite3_module *pModule; /* The module for this virtual table */
1.4 misho 7063: int nRef; /* Number of open cursors */
1.2 misho 7064: char *zErrMsg; /* Error message from sqlite3_mprintf() */
7065: /* Virtual table implementations will typically add additional fields */
7066: };
7067:
7068: /*
7069: ** CAPI3REF: Virtual Table Cursor Object
7070: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7071: **
7072: ** Every [virtual table module] implementation uses a subclass of the
7073: ** following structure to describe cursors that point into the
7074: ** [virtual table] and are used
7075: ** to loop through the virtual table. Cursors are created using the
7076: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7077: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7078: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7079: ** of the module. Each module implementation will define
7080: ** the content of a cursor structure to suit its own needs.
7081: **
7082: ** This superclass exists in order to define fields of the cursor that
7083: ** are common to all implementations.
7084: */
7085: struct sqlite3_vtab_cursor {
7086: sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7087: /* Virtual table implementations will typically add additional fields */
7088: };
7089:
7090: /*
7091: ** CAPI3REF: Declare The Schema Of A Virtual Table
7092: **
7093: ** ^The [xCreate] and [xConnect] methods of a
7094: ** [virtual table module] call this interface
7095: ** to declare the format (the names and datatypes of the columns) of
7096: ** the virtual tables they implement.
7097: */
7098: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7099:
7100: /*
7101: ** CAPI3REF: Overload A Function For A Virtual Table
1.4 misho 7102: ** METHOD: sqlite3
1.2 misho 7103: **
7104: ** ^(Virtual tables can provide alternative implementations of functions
1.5 misho 7105: ** using the [xFindFunction] method of the [virtual table module].
1.2 misho 7106: ** But global versions of those functions
7107: ** must exist in order to be overloaded.)^
7108: **
7109: ** ^(This API makes sure a global version of a function with a particular
7110: ** name and number of parameters exists. If no such function exists
7111: ** before this API is called, a new function is created.)^ ^The implementation
7112: ** of the new function always causes an exception to be thrown. So
7113: ** the new function is not good for anything by itself. Its only
7114: ** purpose is to be a placeholder function that can be overloaded
7115: ** by a [virtual table].
7116: */
7117: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7118:
7119: /*
7120: ** The interface to the virtual-table mechanism defined above (back up
7121: ** to a comment remarkably similar to this one) is currently considered
7122: ** to be experimental. The interface might change in incompatible ways.
7123: ** If this is a problem for you, do not use the interface at this time.
7124: **
7125: ** When the virtual-table mechanism stabilizes, we will declare the
7126: ** interface fixed, support it indefinitely, and remove this comment.
7127: */
7128:
7129: /*
7130: ** CAPI3REF: A Handle To An Open BLOB
7131: ** KEYWORDS: {BLOB handle} {BLOB handles}
7132: **
7133: ** An instance of this object represents an open BLOB on which
7134: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7135: ** ^Objects of this type are created by [sqlite3_blob_open()]
7136: ** and destroyed by [sqlite3_blob_close()].
7137: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7138: ** can be used to read or write small subsections of the BLOB.
7139: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7140: */
7141: typedef struct sqlite3_blob sqlite3_blob;
7142:
7143: /*
7144: ** CAPI3REF: Open A BLOB For Incremental I/O
1.4 misho 7145: ** METHOD: sqlite3
7146: ** CONSTRUCTOR: sqlite3_blob
1.2 misho 7147: **
7148: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7149: ** in row iRow, column zColumn, table zTable in database zDb;
7150: ** in other words, the same BLOB that would be selected by:
7151: **
7152: ** <pre>
7153: ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7154: ** </pre>)^
7155: **
1.5 misho 7156: ** ^(Parameter zDb is not the filename that contains the database, but
1.4 misho 7157: ** rather the symbolic name of the database. For attached databases, this is
7158: ** the name that appears after the AS keyword in the [ATTACH] statement.
7159: ** For the main database file, the database name is "main". For TEMP
7160: ** tables, the database name is "temp".)^
7161: **
1.2 misho 7162: ** ^If the flags parameter is non-zero, then the BLOB is opened for read
1.4 misho 7163: ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7164: ** read-only access.
7165: **
7166: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7167: ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7168: ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
1.5 misho 7169: ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
1.4 misho 7170: ** on *ppBlob after this function it returns.
7171: **
7172: ** This function fails with SQLITE_ERROR if any of the following are true:
7173: ** <ul>
1.5 misho 7174: ** <li> ^(Database zDb does not exist)^,
7175: ** <li> ^(Table zTable does not exist within database zDb)^,
7176: ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
1.4 misho 7177: ** <li> ^(Column zColumn does not exist)^,
7178: ** <li> ^(Row iRow is not present in the table)^,
7179: ** <li> ^(The specified column of row iRow contains a value that is not
7180: ** a TEXT or BLOB value)^,
1.5 misho 7181: ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
1.4 misho 7182: ** constraint and the blob is being opened for read/write access)^,
1.5 misho 7183: ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
1.4 misho 7184: ** column zColumn is part of a [child key] definition and the blob is
7185: ** being opened for read/write access)^.
7186: ** </ul>
7187: **
1.5 misho 7188: ** ^Unless it returns SQLITE_MISUSE, this function sets the
7189: ** [database connection] error code and message accessible via
7190: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7191: **
7192: ** A BLOB referenced by sqlite3_blob_open() may be read using the
7193: ** [sqlite3_blob_read()] interface and modified by using
7194: ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7195: ** different row of the same table using the [sqlite3_blob_reopen()]
7196: ** interface. However, the column, table, or database of a [BLOB handle]
7197: ** cannot be changed after the [BLOB handle] is opened.
1.2 misho 7198: **
7199: ** ^(If the row that a BLOB handle points to is modified by an
7200: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7201: ** then the BLOB handle is marked as "expired".
7202: ** This is true if any column of the row is changed, even a column
7203: ** other than the one the BLOB handle is open on.)^
7204: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7205: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7206: ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7207: ** rolled back by the expiration of the BLOB. Such changes will eventually
7208: ** commit if the transaction continues to completion.)^
7209: **
7210: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7211: ** the opened blob. ^The size of a blob may not be changed by this
7212: ** interface. Use the [UPDATE] SQL command to change the size of a
7213: ** blob.
7214: **
7215: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
1.5 misho 7216: ** and the built-in [zeroblob] SQL function may be used to create a
1.4 misho 7217: ** zero-filled blob to read or write using the incremental-blob interface.
1.2 misho 7218: **
7219: ** To avoid a resource leak, every open [BLOB handle] should eventually
7220: ** be released by a call to [sqlite3_blob_close()].
1.5 misho 7221: **
7222: ** See also: [sqlite3_blob_close()],
7223: ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7224: ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
1.2 misho 7225: */
7226: SQLITE_API int sqlite3_blob_open(
7227: sqlite3*,
7228: const char *zDb,
7229: const char *zTable,
7230: const char *zColumn,
7231: sqlite3_int64 iRow,
7232: int flags,
7233: sqlite3_blob **ppBlob
7234: );
7235:
7236: /*
7237: ** CAPI3REF: Move a BLOB Handle to a New Row
1.4 misho 7238: ** METHOD: sqlite3_blob
1.2 misho 7239: **
1.5 misho 7240: ** ^This function is used to move an existing [BLOB handle] so that it points
1.2 misho 7241: ** to a different row of the same database table. ^The new row is identified
7242: ** by the rowid value passed as the second argument. Only the row can be
7243: ** changed. ^The database, table and column on which the blob handle is open
1.5 misho 7244: ** remain the same. Moving an existing [BLOB handle] to a new row is
1.2 misho 7245: ** faster than closing the existing handle and opening a new one.
7246: **
7247: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7248: ** it must exist and there must be either a blob or text value stored in
7249: ** the nominated column.)^ ^If the new row is not present in the table, or if
7250: ** it does not contain a blob or text value, or if another error occurs, an
7251: ** SQLite error code is returned and the blob handle is considered aborted.
7252: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7253: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7254: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7255: ** always returns zero.
7256: **
7257: ** ^This function sets the database handle error code and message.
7258: */
1.4 misho 7259: SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
1.2 misho 7260:
7261: /*
7262: ** CAPI3REF: Close A BLOB Handle
1.4 misho 7263: ** DESTRUCTOR: sqlite3_blob
1.2 misho 7264: **
1.4 misho 7265: ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
1.5 misho 7266: ** unconditionally. Even if this routine returns an error code, the
1.4 misho 7267: ** handle is still closed.)^
7268: **
7269: ** ^If the blob handle being closed was opened for read-write access, and if
7270: ** the database is in auto-commit mode and there are no other open read-write
7271: ** blob handles or active write statements, the current transaction is
7272: ** committed. ^If an error occurs while committing the transaction, an error
7273: ** code is returned and the transaction rolled back.
7274: **
7275: ** Calling this function with an argument that is not a NULL pointer or an
1.5 misho 7276: ** open blob handle results in undefined behaviour. ^Calling this routine
7277: ** with a null pointer (such as would be returned by a failed call to
1.4 misho 7278: ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
1.5 misho 7279: ** is passed a valid open blob handle, the values returned by the
1.4 misho 7280: ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
1.2 misho 7281: */
7282: SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7283:
7284: /*
7285: ** CAPI3REF: Return The Size Of An Open BLOB
1.4 misho 7286: ** METHOD: sqlite3_blob
1.2 misho 7287: **
1.5 misho 7288: ** ^Returns the size in bytes of the BLOB accessible via the
1.2 misho 7289: ** successfully opened [BLOB handle] in its only argument. ^The
7290: ** incremental blob I/O routines can only read or overwriting existing
7291: ** blob content; they cannot change the size of a blob.
7292: **
7293: ** This routine only works on a [BLOB handle] which has been created
7294: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7295: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7296: ** to this routine results in undefined and probably undesirable behavior.
7297: */
7298: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7299:
7300: /*
7301: ** CAPI3REF: Read Data From A BLOB Incrementally
1.4 misho 7302: ** METHOD: sqlite3_blob
1.2 misho 7303: **
7304: ** ^(This function is used to read data from an open [BLOB handle] into a
7305: ** caller-supplied buffer. N bytes of data are copied into buffer Z
7306: ** from the open BLOB, starting at offset iOffset.)^
7307: **
7308: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7309: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7310: ** less than zero, [SQLITE_ERROR] is returned and no data is read.
7311: ** ^The size of the blob (and hence the maximum value of N+iOffset)
7312: ** can be determined using the [sqlite3_blob_bytes()] interface.
7313: **
7314: ** ^An attempt to read from an expired [BLOB handle] fails with an
7315: ** error code of [SQLITE_ABORT].
7316: **
7317: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7318: ** Otherwise, an [error code] or an [extended error code] is returned.)^
7319: **
7320: ** This routine only works on a [BLOB handle] which has been created
7321: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7322: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7323: ** to this routine results in undefined and probably undesirable behavior.
7324: **
7325: ** See also: [sqlite3_blob_write()].
7326: */
7327: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7328:
7329: /*
7330: ** CAPI3REF: Write Data Into A BLOB Incrementally
1.4 misho 7331: ** METHOD: sqlite3_blob
1.2 misho 7332: **
1.4 misho 7333: ** ^(This function is used to write data into an open [BLOB handle] from a
7334: ** caller-supplied buffer. N bytes of data are copied from the buffer Z
7335: ** into the open BLOB, starting at offset iOffset.)^
7336: **
7337: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7338: ** Otherwise, an [error code] or an [extended error code] is returned.)^
1.5 misho 7339: ** ^Unless SQLITE_MISUSE is returned, this function sets the
7340: ** [database connection] error code and message accessible via
7341: ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
1.2 misho 7342: **
7343: ** ^If the [BLOB handle] passed as the first argument was not opened for
7344: ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7345: ** this function returns [SQLITE_READONLY].
7346: **
1.4 misho 7347: ** This function may only modify the contents of the BLOB; it is
1.2 misho 7348: ** not possible to increase the size of a BLOB using this API.
7349: ** ^If offset iOffset is less than N bytes from the end of the BLOB,
1.5 misho 7350: ** [SQLITE_ERROR] is returned and no data is written. The size of the
7351: ** BLOB (and hence the maximum value of N+iOffset) can be determined
7352: ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
1.4 misho 7353: ** than zero [SQLITE_ERROR] is returned and no data is written.
1.2 misho 7354: **
7355: ** ^An attempt to write to an expired [BLOB handle] fails with an
7356: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7357: ** before the [BLOB handle] expired are not rolled back by the
7358: ** expiration of the handle, though of course those changes might
7359: ** have been overwritten by the statement that expired the BLOB handle
7360: ** or by other independent statements.
7361: **
7362: ** This routine only works on a [BLOB handle] which has been created
7363: ** by a prior successful call to [sqlite3_blob_open()] and which has not
7364: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7365: ** to this routine results in undefined and probably undesirable behavior.
7366: **
7367: ** See also: [sqlite3_blob_read()].
7368: */
7369: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7370:
7371: /*
7372: ** CAPI3REF: Virtual File System Objects
7373: **
7374: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7375: ** that SQLite uses to interact
7376: ** with the underlying operating system. Most SQLite builds come with a
7377: ** single default VFS that is appropriate for the host computer.
7378: ** New VFSes can be registered and existing VFSes can be unregistered.
7379: ** The following interfaces are provided.
7380: **
7381: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7382: ** ^Names are case sensitive.
7383: ** ^Names are zero-terminated UTF-8 strings.
7384: ** ^If there is no match, a NULL pointer is returned.
7385: ** ^If zVfsName is NULL then the default VFS is returned.
7386: **
7387: ** ^New VFSes are registered with sqlite3_vfs_register().
7388: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7389: ** ^The same VFS can be registered multiple times without injury.
7390: ** ^To make an existing VFS into the default VFS, register it again
7391: ** with the makeDflt flag set. If two different VFSes with the
7392: ** same name are registered, the behavior is undefined. If a
7393: ** VFS is registered with a name that is NULL or an empty string,
7394: ** then the behavior is undefined.
7395: **
7396: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7397: ** ^(If the default VFS is unregistered, another VFS is chosen as
7398: ** the default. The choice for the new VFS is arbitrary.)^
7399: */
7400: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7401: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7402: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7403:
7404: /*
7405: ** CAPI3REF: Mutexes
7406: **
7407: ** The SQLite core uses these routines for thread
7408: ** synchronization. Though they are intended for internal
7409: ** use by SQLite, code that links against SQLite is
7410: ** permitted to use any of these routines.
7411: **
7412: ** The SQLite source code contains multiple implementations
7413: ** of these mutex routines. An appropriate implementation
1.4 misho 7414: ** is selected automatically at compile-time. The following
1.2 misho 7415: ** implementations are available in the SQLite core:
7416: **
7417: ** <ul>
7418: ** <li> SQLITE_MUTEX_PTHREADS
7419: ** <li> SQLITE_MUTEX_W32
7420: ** <li> SQLITE_MUTEX_NOOP
1.4 misho 7421: ** </ul>
1.2 misho 7422: **
1.4 misho 7423: ** The SQLITE_MUTEX_NOOP implementation is a set of routines
1.2 misho 7424: ** that does no real locking and is appropriate for use in
1.4 misho 7425: ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
1.3 misho 7426: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7427: ** and Windows.
1.2 misho 7428: **
1.4 misho 7429: ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
1.2 misho 7430: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7431: ** implementation is included with the library. In this case the
7432: ** application must supply a custom mutex implementation using the
7433: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7434: ** before calling sqlite3_initialize() or any other public sqlite3_
1.4 misho 7435: ** function that calls sqlite3_initialize().
1.2 misho 7436: **
7437: ** ^The sqlite3_mutex_alloc() routine allocates a new
1.4 misho 7438: ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7439: ** routine returns NULL if it is unable to allocate the requested
7440: ** mutex. The argument to sqlite3_mutex_alloc() must one of these
7441: ** integer constants:
1.2 misho 7442: **
7443: ** <ul>
7444: ** <li> SQLITE_MUTEX_FAST
7445: ** <li> SQLITE_MUTEX_RECURSIVE
1.5 misho 7446: ** <li> SQLITE_MUTEX_STATIC_MAIN
1.2 misho 7447: ** <li> SQLITE_MUTEX_STATIC_MEM
1.4 misho 7448: ** <li> SQLITE_MUTEX_STATIC_OPEN
1.2 misho 7449: ** <li> SQLITE_MUTEX_STATIC_PRNG
7450: ** <li> SQLITE_MUTEX_STATIC_LRU
1.4 misho 7451: ** <li> SQLITE_MUTEX_STATIC_PMEM
7452: ** <li> SQLITE_MUTEX_STATIC_APP1
7453: ** <li> SQLITE_MUTEX_STATIC_APP2
7454: ** <li> SQLITE_MUTEX_STATIC_APP3
7455: ** <li> SQLITE_MUTEX_STATIC_VFS1
7456: ** <li> SQLITE_MUTEX_STATIC_VFS2
7457: ** <li> SQLITE_MUTEX_STATIC_VFS3
7458: ** </ul>
1.2 misho 7459: **
7460: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7461: ** cause sqlite3_mutex_alloc() to create
7462: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7463: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7464: ** The mutex implementation does not need to make a distinction
7465: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
1.4 misho 7466: ** not want to. SQLite will only request a recursive mutex in
7467: ** cases where it really needs one. If a faster non-recursive mutex
1.2 misho 7468: ** implementation is available on the host platform, the mutex subsystem
7469: ** might return such a mutex in response to SQLITE_MUTEX_FAST.
7470: **
7471: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7472: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
1.4 misho 7473: ** a pointer to a static preexisting mutex. ^Nine static mutexes are
1.2 misho 7474: ** used by the current version of SQLite. Future versions of SQLite
7475: ** may add additional static mutexes. Static mutexes are for internal
7476: ** use by SQLite only. Applications that use SQLite mutexes should
7477: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7478: ** SQLITE_MUTEX_RECURSIVE.
7479: **
7480: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7481: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
1.4 misho 7482: ** returns a different mutex on every call. ^For the static
1.2 misho 7483: ** mutex types, the same mutex is returned on every call that has
7484: ** the same type number.
7485: **
7486: ** ^The sqlite3_mutex_free() routine deallocates a previously
1.4 misho 7487: ** allocated dynamic mutex. Attempting to deallocate a static
7488: ** mutex results in undefined behavior.
1.2 misho 7489: **
7490: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7491: ** to enter a mutex. ^If another thread is already within the mutex,
7492: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7493: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7494: ** upon successful entry. ^(Mutexes created using
7495: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
1.4 misho 7496: ** In such cases, the
1.2 misho 7497: ** mutex must be exited an equal number of times before another thread
1.4 misho 7498: ** can enter.)^ If the same thread tries to enter any mutex other
7499: ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
1.2 misho 7500: **
7501: ** ^(Some systems (for example, Windows 95) do not support the operation
7502: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
1.4 misho 7503: ** will always return SQLITE_BUSY. The SQLite core only ever uses
1.5 misho 7504: ** sqlite3_mutex_try() as an optimization so this is acceptable
1.4 misho 7505: ** behavior.)^
1.2 misho 7506: **
7507: ** ^The sqlite3_mutex_leave() routine exits a mutex that was
1.4 misho 7508: ** previously entered by the same thread. The behavior
1.2 misho 7509: ** is undefined if the mutex is not currently entered by the
1.4 misho 7510: ** calling thread or is not currently allocated.
1.2 misho 7511: **
7512: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7513: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7514: ** behave as no-ops.
7515: **
7516: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7517: */
7518: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7519: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7520: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7521: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7522: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7523:
7524: /*
7525: ** CAPI3REF: Mutex Methods Object
7526: **
7527: ** An instance of this structure defines the low-level routines
7528: ** used to allocate and use mutexes.
7529: **
7530: ** Usually, the default mutex implementations provided by SQLite are
1.4 misho 7531: ** sufficient, however the application has the option of substituting a custom
1.2 misho 7532: ** implementation for specialized deployments or systems for which SQLite
1.4 misho 7533: ** does not provide a suitable implementation. In this case, the application
1.2 misho 7534: ** creates and populates an instance of this structure to pass
7535: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7536: ** Additionally, an instance of this structure can be used as an
7537: ** output variable when querying the system for the current mutex
7538: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7539: **
7540: ** ^The xMutexInit method defined by this structure is invoked as
7541: ** part of system initialization by the sqlite3_initialize() function.
7542: ** ^The xMutexInit routine is called by SQLite exactly once for each
7543: ** effective call to [sqlite3_initialize()].
7544: **
7545: ** ^The xMutexEnd method defined by this structure is invoked as
7546: ** part of system shutdown by the sqlite3_shutdown() function. The
7547: ** implementation of this method is expected to release all outstanding
7548: ** resources obtained by the mutex methods implementation, especially
7549: ** those obtained by the xMutexInit method. ^The xMutexEnd()
7550: ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7551: **
7552: ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7553: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7554: ** xMutexNotheld) implement the following interfaces (respectively):
7555: **
7556: ** <ul>
7557: ** <li> [sqlite3_mutex_alloc()] </li>
7558: ** <li> [sqlite3_mutex_free()] </li>
7559: ** <li> [sqlite3_mutex_enter()] </li>
7560: ** <li> [sqlite3_mutex_try()] </li>
7561: ** <li> [sqlite3_mutex_leave()] </li>
7562: ** <li> [sqlite3_mutex_held()] </li>
7563: ** <li> [sqlite3_mutex_notheld()] </li>
7564: ** </ul>)^
7565: **
7566: ** The only difference is that the public sqlite3_XXX functions enumerated
7567: ** above silently ignore any invocations that pass a NULL pointer instead
7568: ** of a valid mutex handle. The implementations of the methods defined
1.5 misho 7569: ** by this structure are not required to handle this case. The results
1.2 misho 7570: ** of passing a NULL pointer instead of a valid mutex handle are undefined
7571: ** (i.e. it is acceptable to provide an implementation that segfaults if
7572: ** it is passed a NULL pointer).
7573: **
1.4 misho 7574: ** The xMutexInit() method must be threadsafe. It must be harmless to
1.2 misho 7575: ** invoke xMutexInit() multiple times within the same process and without
7576: ** intervening calls to xMutexEnd(). Second and subsequent calls to
7577: ** xMutexInit() must be no-ops.
7578: **
1.4 misho 7579: ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7580: ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
1.2 misho 7581: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7582: ** memory allocation for a fast or recursive mutex.
7583: **
7584: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7585: ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7586: ** If xMutexInit fails in any way, it is expected to clean up after itself
7587: ** prior to returning.
7588: */
7589: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7590: struct sqlite3_mutex_methods {
7591: int (*xMutexInit)(void);
7592: int (*xMutexEnd)(void);
7593: sqlite3_mutex *(*xMutexAlloc)(int);
7594: void (*xMutexFree)(sqlite3_mutex *);
7595: void (*xMutexEnter)(sqlite3_mutex *);
7596: int (*xMutexTry)(sqlite3_mutex *);
7597: void (*xMutexLeave)(sqlite3_mutex *);
7598: int (*xMutexHeld)(sqlite3_mutex *);
7599: int (*xMutexNotheld)(sqlite3_mutex *);
7600: };
7601:
7602: /*
7603: ** CAPI3REF: Mutex Verification Routines
7604: **
7605: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
1.4 misho 7606: ** are intended for use inside assert() statements. The SQLite core
1.2 misho 7607: ** never uses these routines except inside an assert() and applications
1.4 misho 7608: ** are advised to follow the lead of the core. The SQLite core only
1.2 misho 7609: ** provides implementations for these routines when it is compiled
1.4 misho 7610: ** with the SQLITE_DEBUG flag. External mutex implementations
1.2 misho 7611: ** are only required to provide these routines if SQLITE_DEBUG is
7612: ** defined and if NDEBUG is not defined.
7613: **
1.4 misho 7614: ** These routines should return true if the mutex in their argument
1.2 misho 7615: ** is held or not held, respectively, by the calling thread.
7616: **
1.4 misho 7617: ** The implementation is not required to provide versions of these
1.2 misho 7618: ** routines that actually work. If the implementation does not provide working
7619: ** versions of these routines, it should at least provide stubs that always
7620: ** return true so that one does not get spurious assertion failures.
7621: **
1.4 misho 7622: ** If the argument to sqlite3_mutex_held() is a NULL pointer then
1.2 misho 7623: ** the routine should return 1. This seems counter-intuitive since
7624: ** clearly the mutex cannot be held if it does not exist. But
7625: ** the reason the mutex does not exist is because the build is not
7626: ** using mutexes. And we do not want the assert() containing the
7627: ** call to sqlite3_mutex_held() to fail, so a non-zero return is
1.4 misho 7628: ** the appropriate thing to do. The sqlite3_mutex_notheld()
1.2 misho 7629: ** interface should also return 1 when given a NULL pointer.
7630: */
7631: #ifndef NDEBUG
7632: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7633: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7634: #endif
7635:
7636: /*
7637: ** CAPI3REF: Mutex Types
7638: **
7639: ** The [sqlite3_mutex_alloc()] interface takes a single argument
7640: ** which is one of these integer constants.
7641: **
7642: ** The set of static mutexes may change from one SQLite release to the
7643: ** next. Applications that override the built-in mutex logic must be
7644: ** prepared to accommodate additional static mutexes.
7645: */
7646: #define SQLITE_MUTEX_FAST 0
7647: #define SQLITE_MUTEX_RECURSIVE 1
1.5 misho 7648: #define SQLITE_MUTEX_STATIC_MAIN 2
1.2 misho 7649: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7650: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7651: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
1.5 misho 7652: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
1.2 misho 7653: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7654: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7655: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
1.4 misho 7656: #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7657: #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7658: #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7659: #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7660: #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7661: #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
1.2 misho 7662:
1.5 misho 7663: /* Legacy compatibility: */
7664: #define SQLITE_MUTEX_STATIC_MASTER 2
7665:
7666:
1.2 misho 7667: /*
7668: ** CAPI3REF: Retrieve the mutex for a database connection
1.4 misho 7669: ** METHOD: sqlite3
1.2 misho 7670: **
1.5 misho 7671: ** ^This interface returns a pointer the [sqlite3_mutex] object that
1.2 misho 7672: ** serializes access to the [database connection] given in the argument
7673: ** when the [threading mode] is Serialized.
7674: ** ^If the [threading mode] is Single-thread or Multi-thread then this
7675: ** routine returns a NULL pointer.
7676: */
7677: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7678:
7679: /*
7680: ** CAPI3REF: Low-Level Control Of Database Files
1.4 misho 7681: ** METHOD: sqlite3
1.5 misho 7682: ** KEYWORDS: {file control}
1.2 misho 7683: **
7684: ** ^The [sqlite3_file_control()] interface makes a direct call to the
7685: ** xFileControl method for the [sqlite3_io_methods] object associated
7686: ** with a particular database identified by the second argument. ^The
7687: ** name of the database is "main" for the main database or "temp" for the
7688: ** TEMP database, or the name that appears after the AS keyword for
7689: ** databases that are added using the [ATTACH] SQL command.
7690: ** ^A NULL pointer can be used in place of "main" to refer to the
7691: ** main database file.
7692: ** ^The third and fourth parameters to this routine
7693: ** are passed directly through to the second and third parameters of
7694: ** the xFileControl method. ^The return value of the xFileControl
7695: ** method becomes the return value of this routine.
7696: **
1.5 misho 7697: ** A few opcodes for [sqlite3_file_control()] are handled directly
7698: ** by the SQLite core and never invoke the
7699: ** sqlite3_io_methods.xFileControl method.
7700: ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
1.2 misho 7701: ** a pointer to the underlying [sqlite3_file] object to be written into
1.5 misho 7702: ** the space pointed to by the 4th parameter. The
7703: ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7704: ** the [sqlite3_file] object associated with the journal file instead of
7705: ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7706: ** a pointer to the underlying [sqlite3_vfs] object for the file.
7707: ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7708: ** from the pager.
1.2 misho 7709: **
7710: ** ^If the second parameter (zDbName) does not match the name of any
7711: ** open database file, then SQLITE_ERROR is returned. ^This error
7712: ** code is not remembered and will not be recalled by [sqlite3_errcode()]
7713: ** or [sqlite3_errmsg()]. The underlying xFileControl method might
7714: ** also return SQLITE_ERROR. There is no way to distinguish between
7715: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7716: ** xFileControl method.
7717: **
1.5 misho 7718: ** See also: [file control opcodes]
1.2 misho 7719: */
7720: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7721:
7722: /*
7723: ** CAPI3REF: Testing Interface
7724: **
7725: ** ^The sqlite3_test_control() interface is used to read out internal
7726: ** state of SQLite and to inject faults into SQLite for testing
7727: ** purposes. ^The first parameter is an operation code that determines
7728: ** the number, meaning, and operation of all subsequent parameters.
7729: **
7730: ** This interface is not for use by applications. It exists solely
7731: ** for verifying the correct operation of the SQLite library. Depending
7732: ** on how the SQLite library is compiled, this interface might not exist.
7733: **
7734: ** The details of the operation codes, their meanings, the parameters
7735: ** they take, and what they do are all subject to change without notice.
7736: ** Unlike most of the SQLite API, this function is not guaranteed to
7737: ** operate consistently from one release to the next.
7738: */
7739: SQLITE_API int sqlite3_test_control(int op, ...);
7740:
7741: /*
7742: ** CAPI3REF: Testing Interface Operation Codes
7743: **
7744: ** These constants are the valid operation code parameters used
7745: ** as the first argument to [sqlite3_test_control()].
7746: **
7747: ** These parameters and their meanings are subject to change
7748: ** without notice. These values are for testing purposes only.
7749: ** Applications should not use any of these parameters or the
7750: ** [sqlite3_test_control()] interface.
7751: */
7752: #define SQLITE_TESTCTRL_FIRST 5
7753: #define SQLITE_TESTCTRL_PRNG_SAVE 5
7754: #define SQLITE_TESTCTRL_PRNG_RESTORE 6
1.5 misho 7755: #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
1.2 misho 7756: #define SQLITE_TESTCTRL_BITVEC_TEST 8
7757: #define SQLITE_TESTCTRL_FAULT_INSTALL 9
7758: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7759: #define SQLITE_TESTCTRL_PENDING_BYTE 11
7760: #define SQLITE_TESTCTRL_ASSERT 12
7761: #define SQLITE_TESTCTRL_ALWAYS 13
1.5 misho 7762: #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
1.2 misho 7763: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
1.5 misho 7764: #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7765: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7766: #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
1.2 misho 7767: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
1.4 misho 7768: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
1.5 misho 7769: #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
1.4 misho 7770: #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7771: #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7772: #define SQLITE_TESTCTRL_BYTEORDER 22
7773: #define SQLITE_TESTCTRL_ISINIT 23
7774: #define SQLITE_TESTCTRL_SORTER_MMAP 24
7775: #define SQLITE_TESTCTRL_IMPOSTER 25
1.5 misho 7776: #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7777: #define SQLITE_TESTCTRL_RESULT_INTREAL 27
7778: #define SQLITE_TESTCTRL_PRNG_SEED 28
7779: #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
1.6 ! misho 7780: #define SQLITE_TESTCTRL_SEEK_COUNT 30
! 7781: #define SQLITE_TESTCTRL_TRACEFLAGS 31
! 7782: #define SQLITE_TESTCTRL_LAST 31 /* Largest TESTCTRL */
1.5 misho 7783:
7784: /*
7785: ** CAPI3REF: SQL Keyword Checking
7786: **
7787: ** These routines provide access to the set of SQL language keywords
7788: ** recognized by SQLite. Applications can uses these routines to determine
7789: ** whether or not a specific identifier needs to be escaped (for example,
7790: ** by enclosing in double-quotes) so as not to confuse the parser.
7791: **
7792: ** The sqlite3_keyword_count() interface returns the number of distinct
7793: ** keywords understood by SQLite.
7794: **
7795: ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7796: ** makes *Z point to that keyword expressed as UTF8 and writes the number
7797: ** of bytes in the keyword into *L. The string that *Z points to is not
7798: ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7799: ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7800: ** or L are NULL or invalid pointers then calls to
7801: ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7802: **
7803: ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7804: ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7805: ** if it is and zero if not.
7806: **
7807: ** The parser used by SQLite is forgiving. It is often possible to use
7808: ** a keyword as an identifier as long as such use does not result in a
7809: ** parsing ambiguity. For example, the statement
7810: ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7811: ** creates a new table named "BEGIN" with three columns named
7812: ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7813: ** using keywords as identifiers. Common techniques used to avoid keyword
7814: ** name collisions include:
7815: ** <ul>
7816: ** <li> Put all identifier names inside double-quotes. This is the official
7817: ** SQL way to escape identifier names.
7818: ** <li> Put identifier names inside [...]. This is not standard SQL,
7819: ** but it is what SQL Server does and so lots of programmers use this
7820: ** technique.
7821: ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7822: ** with "Z".
7823: ** <li> Include a digit somewhere in every identifier name.
7824: ** </ul>
7825: **
7826: ** Note that the number of keywords understood by SQLite can depend on
7827: ** compile-time options. For example, "VACUUM" is not a keyword if
7828: ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7829: ** new keywords may be added to future releases of SQLite.
7830: */
7831: SQLITE_API int sqlite3_keyword_count(void);
7832: SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7833: SQLITE_API int sqlite3_keyword_check(const char*,int);
7834:
7835: /*
7836: ** CAPI3REF: Dynamic String Object
7837: ** KEYWORDS: {dynamic string}
7838: **
7839: ** An instance of the sqlite3_str object contains a dynamically-sized
7840: ** string under construction.
7841: **
7842: ** The lifecycle of an sqlite3_str object is as follows:
7843: ** <ol>
7844: ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7845: ** <li> ^Text is appended to the sqlite3_str object using various
7846: ** methods, such as [sqlite3_str_appendf()].
7847: ** <li> ^The sqlite3_str object is destroyed and the string it created
7848: ** is returned using the [sqlite3_str_finish()] interface.
7849: ** </ol>
7850: */
7851: typedef struct sqlite3_str sqlite3_str;
7852:
7853: /*
7854: ** CAPI3REF: Create A New Dynamic String Object
7855: ** CONSTRUCTOR: sqlite3_str
7856: **
7857: ** ^The [sqlite3_str_new(D)] interface allocates and initializes
7858: ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7859: ** [sqlite3_str_new()] must be freed by a subsequent call to
7860: ** [sqlite3_str_finish(X)].
7861: **
7862: ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7863: ** valid [sqlite3_str] object, though in the event of an out-of-memory
7864: ** error the returned object might be a special singleton that will
7865: ** silently reject new text, always return SQLITE_NOMEM from
7866: ** [sqlite3_str_errcode()], always return 0 for
7867: ** [sqlite3_str_length()], and always return NULL from
7868: ** [sqlite3_str_finish(X)]. It is always safe to use the value
7869: ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7870: ** to any of the other [sqlite3_str] methods.
7871: **
7872: ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7873: ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7874: ** length of the string contained in the [sqlite3_str] object will be
7875: ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7876: ** of [SQLITE_MAX_LENGTH].
7877: */
7878: SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7879:
7880: /*
7881: ** CAPI3REF: Finalize A Dynamic String
7882: ** DESTRUCTOR: sqlite3_str
7883: **
7884: ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7885: ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7886: ** that contains the constructed string. The calling application should
7887: ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7888: ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7889: ** errors were encountered during construction of the string. ^The
7890: ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7891: ** string in [sqlite3_str] object X is zero bytes long.
7892: */
7893: SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7894:
7895: /*
7896: ** CAPI3REF: Add Content To A Dynamic String
7897: ** METHOD: sqlite3_str
7898: **
7899: ** These interfaces add content to an sqlite3_str object previously obtained
7900: ** from [sqlite3_str_new()].
7901: **
7902: ** ^The [sqlite3_str_appendf(X,F,...)] and
7903: ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7904: ** functionality of SQLite to append formatted text onto the end of
7905: ** [sqlite3_str] object X.
7906: **
7907: ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7908: ** onto the end of the [sqlite3_str] object X. N must be non-negative.
7909: ** S must contain at least N non-zero bytes of content. To append a
7910: ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7911: ** method instead.
7912: **
7913: ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7914: ** zero-terminated string S onto the end of [sqlite3_str] object X.
7915: **
7916: ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7917: ** single-byte character C onto the end of [sqlite3_str] object X.
7918: ** ^This method can be used, for example, to add whitespace indentation.
7919: **
7920: ** ^The [sqlite3_str_reset(X)] method resets the string under construction
7921: ** inside [sqlite3_str] object X back to zero bytes in length.
7922: **
7923: ** These methods do not return a result code. ^If an error occurs, that fact
7924: ** is recorded in the [sqlite3_str] object and can be recovered by a
7925: ** subsequent call to [sqlite3_str_errcode(X)].
7926: */
7927: SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7928: SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7929: SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7930: SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7931: SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7932: SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7933:
7934: /*
7935: ** CAPI3REF: Status Of A Dynamic String
7936: ** METHOD: sqlite3_str
7937: **
7938: ** These interfaces return the current status of an [sqlite3_str] object.
7939: **
7940: ** ^If any prior errors have occurred while constructing the dynamic string
7941: ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7942: ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7943: ** [SQLITE_NOMEM] following any out-of-memory error, or
7944: ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7945: ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7946: **
7947: ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7948: ** of the dynamic string under construction in [sqlite3_str] object X.
7949: ** ^The length returned by [sqlite3_str_length(X)] does not include the
7950: ** zero-termination byte.
7951: **
7952: ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7953: ** content of the dynamic string under construction in X. The value
7954: ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7955: ** and might be freed or altered by any subsequent method on the same
7956: ** [sqlite3_str] object. Applications must not used the pointer returned
7957: ** [sqlite3_str_value(X)] after any subsequent method call on the same
7958: ** object. ^Applications may change the content of the string returned
7959: ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7960: ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7961: ** write any byte after any subsequent sqlite3_str method call.
7962: */
7963: SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7964: SQLITE_API int sqlite3_str_length(sqlite3_str*);
7965: SQLITE_API char *sqlite3_str_value(sqlite3_str*);
1.2 misho 7966:
7967: /*
7968: ** CAPI3REF: SQLite Runtime Status
7969: **
1.4 misho 7970: ** ^These interfaces are used to retrieve runtime status information
1.2 misho 7971: ** about the performance of SQLite, and optionally to reset various
7972: ** highwater marks. ^The first argument is an integer code for
7973: ** the specific parameter to measure. ^(Recognized integer codes
7974: ** are of the form [status parameters | SQLITE_STATUS_...].)^
7975: ** ^The current value of the parameter is returned into *pCurrent.
7976: ** ^The highest recorded value is returned in *pHighwater. ^If the
7977: ** resetFlag is true, then the highest record value is reset after
7978: ** *pHighwater is written. ^(Some parameters do not record the highest
7979: ** value. For those parameters
7980: ** nothing is written into *pHighwater and the resetFlag is ignored.)^
7981: ** ^(Other parameters record only the highwater mark and not the current
7982: ** value. For these latter parameters nothing is written into *pCurrent.)^
7983: **
1.4 misho 7984: ** ^The sqlite3_status() and sqlite3_status64() routines return
7985: ** SQLITE_OK on success and a non-zero [error code] on failure.
1.2 misho 7986: **
1.4 misho 7987: ** If either the current value or the highwater mark is too large to
7988: ** be represented by a 32-bit integer, then the values returned by
7989: ** sqlite3_status() are undefined.
1.2 misho 7990: **
7991: ** See also: [sqlite3_db_status()]
7992: */
7993: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
1.4 misho 7994: SQLITE_API int sqlite3_status64(
7995: int op,
7996: sqlite3_int64 *pCurrent,
7997: sqlite3_int64 *pHighwater,
7998: int resetFlag
7999: );
1.2 misho 8000:
8001:
8002: /*
8003: ** CAPI3REF: Status Parameters
8004: ** KEYWORDS: {status parameters}
8005: **
8006: ** These integer constants designate various run-time status parameters
8007: ** that can be returned by [sqlite3_status()].
8008: **
8009: ** <dl>
8010: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8011: ** <dd>This parameter is the current amount of memory checked out
8012: ** using [sqlite3_malloc()], either directly or indirectly. The
8013: ** figure includes calls made to [sqlite3_malloc()] by the application
1.5 misho 8014: ** and internal memory usage by the SQLite library. Auxiliary page-cache
1.2 misho 8015: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8016: ** this parameter. The amount returned is the sum of the allocation
8017: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8018: **
8019: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8020: ** <dd>This parameter records the largest memory allocation request
8021: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8022: ** internal equivalents). Only the value returned in the
1.5 misho 8023: ** *pHighwater parameter to [sqlite3_status()] is of interest.
1.2 misho 8024: ** The value written into the *pCurrent parameter is undefined.</dd>)^
8025: **
8026: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8027: ** <dd>This parameter records the number of separate memory allocations
8028: ** currently checked out.</dd>)^
8029: **
8030: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8031: ** <dd>This parameter returns the number of pages used out of the
1.5 misho 8032: ** [pagecache memory allocator] that was configured using
1.2 misho 8033: ** [SQLITE_CONFIG_PAGECACHE]. The
8034: ** value returned is in pages, not in bytes.</dd>)^
8035: **
1.5 misho 8036: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
1.2 misho 8037: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8038: ** <dd>This parameter returns the number of bytes of page cache
8039: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8040: ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8041: ** returned value includes allocations that overflowed because they
8042: ** where too large (they were larger than the "sz" parameter to
8043: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8044: ** no space was left in the page cache.</dd>)^
8045: **
8046: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8047: ** <dd>This parameter records the largest memory allocation request
1.5 misho 8048: ** handed to the [pagecache memory allocator]. Only the value returned in the
8049: ** *pHighwater parameter to [sqlite3_status()] is of interest.
1.2 misho 8050: ** The value written into the *pCurrent parameter is undefined.</dd>)^
8051: **
1.5 misho 8052: ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8053: ** <dd>No longer used.</dd>
1.2 misho 8054: **
8055: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
1.5 misho 8056: ** <dd>No longer used.</dd>
1.2 misho 8057: **
1.5 misho 8058: ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8059: ** <dd>No longer used.</dd>
1.2 misho 8060: **
8061: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
1.5 misho 8062: ** <dd>The *pHighwater parameter records the deepest parser stack.
1.4 misho 8063: ** The *pCurrent value is undefined. The *pHighwater value is only
1.2 misho 8064: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8065: ** </dl>
8066: **
8067: ** New status parameters may be added from time to time.
8068: */
8069: #define SQLITE_STATUS_MEMORY_USED 0
8070: #define SQLITE_STATUS_PAGECACHE_USED 1
8071: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
1.5 misho 8072: #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8073: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
1.2 misho 8074: #define SQLITE_STATUS_MALLOC_SIZE 5
8075: #define SQLITE_STATUS_PARSER_STACK 6
8076: #define SQLITE_STATUS_PAGECACHE_SIZE 7
1.5 misho 8077: #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
1.2 misho 8078: #define SQLITE_STATUS_MALLOC_COUNT 9
8079:
8080: /*
8081: ** CAPI3REF: Database Connection Status
1.4 misho 8082: ** METHOD: sqlite3
1.2 misho 8083: **
1.5 misho 8084: ** ^This interface is used to retrieve runtime status information
1.2 misho 8085: ** about a single [database connection]. ^The first argument is the
8086: ** database connection object to be interrogated. ^The second argument
8087: ** is an integer constant, taken from the set of
8088: ** [SQLITE_DBSTATUS options], that
1.5 misho 8089: ** determines the parameter to interrogate. The set of
1.2 misho 8090: ** [SQLITE_DBSTATUS options] is likely
8091: ** to grow in future releases of SQLite.
8092: **
8093: ** ^The current value of the requested parameter is written into *pCur
8094: ** and the highest instantaneous value is written into *pHiwtr. ^If
8095: ** the resetFlg is true, then the highest instantaneous value is
8096: ** reset back down to the current value.
8097: **
8098: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8099: ** non-zero [error code] on failure.
8100: **
8101: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8102: */
8103: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8104:
8105: /*
8106: ** CAPI3REF: Status Parameters for database connections
8107: ** KEYWORDS: {SQLITE_DBSTATUS options}
8108: **
8109: ** These constants are the available integer "verbs" that can be passed as
8110: ** the second argument to the [sqlite3_db_status()] interface.
8111: **
8112: ** New verbs may be added in future releases of SQLite. Existing verbs
8113: ** might be discontinued. Applications should check the return code from
8114: ** [sqlite3_db_status()] to make sure that the call worked.
8115: ** The [sqlite3_db_status()] interface will return a non-zero error code
8116: ** if a discontinued or unsupported verb is invoked.
8117: **
8118: ** <dl>
8119: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8120: ** <dd>This parameter returns the number of lookaside memory slots currently
8121: ** checked out.</dd>)^
8122: **
8123: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
1.5 misho 8124: ** <dd>This parameter returns the number of malloc attempts that were
1.2 misho 8125: ** satisfied using lookaside memory. Only the high-water value is meaningful;
8126: ** the current value is always zero.)^
8127: **
8128: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8129: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8130: ** <dd>This parameter returns the number malloc attempts that might have
8131: ** been satisfied using lookaside memory but failed due to the amount of
8132: ** memory requested being larger than the lookaside slot size.
8133: ** Only the high-water value is meaningful;
8134: ** the current value is always zero.)^
8135: **
8136: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8137: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8138: ** <dd>This parameter returns the number malloc attempts that might have
8139: ** been satisfied using lookaside memory but failed due to all lookaside
8140: ** memory already being in use.
8141: ** Only the high-water value is meaningful;
8142: ** the current value is always zero.)^
8143: **
8144: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
1.4 misho 8145: ** <dd>This parameter returns the approximate number of bytes of heap
1.2 misho 8146: ** memory used by all pager caches associated with the database connection.)^
8147: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8148: **
1.5 misho 8149: ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
1.4 misho 8150: ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8151: ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8152: ** pager cache is shared between two or more connections the bytes of heap
8153: ** memory used by that pager cache is divided evenly between the attached
8154: ** connections.)^ In other words, if none of the pager caches associated
8155: ** with the database connection are shared, this request returns the same
8156: ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8157: ** shared, the value returned by this call will be smaller than that returned
8158: ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8159: ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8160: **
1.2 misho 8161: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
1.4 misho 8162: ** <dd>This parameter returns the approximate number of bytes of heap
1.2 misho 8163: ** memory used to store the schema for all databases associated
1.5 misho 8164: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
1.2 misho 8165: ** ^The full amount of memory used by the schemas is reported, even if the
8166: ** schema memory is shared with other database connections due to
8167: ** [shared cache mode] being enabled.
8168: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8169: **
8170: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
1.4 misho 8171: ** <dd>This parameter returns the approximate number of bytes of heap
1.2 misho 8172: ** and lookaside memory used by all prepared statements associated with
8173: ** the database connection.)^
8174: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8175: ** </dd>
8176: **
8177: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8178: ** <dd>This parameter returns the number of pager cache hits that have
1.5 misho 8179: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
1.2 misho 8180: ** is always 0.
8181: ** </dd>
8182: **
8183: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8184: ** <dd>This parameter returns the number of pager cache misses that have
1.5 misho 8185: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
1.2 misho 8186: ** is always 0.
8187: ** </dd>
1.3 misho 8188: **
8189: ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8190: ** <dd>This parameter returns the number of dirty cache entries that have
8191: ** been written to disk. Specifically, the number of pages written to the
8192: ** wal file in wal mode databases, or the number of pages written to the
8193: ** database file in rollback mode databases. Any pages written as part of
8194: ** transaction rollback or database recovery operations are not included.
8195: ** If an IO or other error occurs while writing a page to disk, the effect
8196: ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8197: ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8198: ** </dd>
1.4 misho 8199: **
1.5 misho 8200: ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8201: ** <dd>This parameter returns the number of dirty cache entries that have
8202: ** been written to disk in the middle of a transaction due to the page
8203: ** cache overflowing. Transactions are more efficient if they are written
8204: ** to disk all at once. When pages spill mid-transaction, that introduces
8205: ** additional overhead. This parameter can be used help identify
8206: ** inefficiencies that can be resolved by increasing the cache size.
8207: ** </dd>
8208: **
1.4 misho 8209: ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8210: ** <dd>This parameter returns zero for the current value if and only if
8211: ** all foreign key constraints (deferred or immediate) have been
8212: ** resolved.)^ ^The highwater mark is always 0.
8213: ** </dd>
1.2 misho 8214: ** </dl>
8215: */
8216: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8217: #define SQLITE_DBSTATUS_CACHE_USED 1
8218: #define SQLITE_DBSTATUS_SCHEMA_USED 2
8219: #define SQLITE_DBSTATUS_STMT_USED 3
8220: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8221: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8222: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8223: #define SQLITE_DBSTATUS_CACHE_HIT 7
8224: #define SQLITE_DBSTATUS_CACHE_MISS 8
1.3 misho 8225: #define SQLITE_DBSTATUS_CACHE_WRITE 9
1.4 misho 8226: #define SQLITE_DBSTATUS_DEFERRED_FKS 10
8227: #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
1.5 misho 8228: #define SQLITE_DBSTATUS_CACHE_SPILL 12
8229: #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
1.2 misho 8230:
8231:
8232: /*
8233: ** CAPI3REF: Prepared Statement Status
1.4 misho 8234: ** METHOD: sqlite3_stmt
1.2 misho 8235: **
8236: ** ^(Each prepared statement maintains various
8237: ** [SQLITE_STMTSTATUS counters] that measure the number
8238: ** of times it has performed specific operations.)^ These counters can
8239: ** be used to monitor the performance characteristics of the prepared
8240: ** statements. For example, if the number of table steps greatly exceeds
8241: ** the number of table searches or result rows, that would tend to indicate
8242: ** that the prepared statement is using a full table scan rather than
1.5 misho 8243: ** an index.
1.2 misho 8244: **
8245: ** ^(This interface is used to retrieve and reset counter values from
8246: ** a [prepared statement]. The first argument is the prepared statement
8247: ** object to be interrogated. The second argument
8248: ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8249: ** to be interrogated.)^
8250: ** ^The current value of the requested counter is returned.
8251: ** ^If the resetFlg is true, then the counter is reset to zero after this
8252: ** interface call returns.
8253: **
8254: ** See also: [sqlite3_status()] and [sqlite3_db_status()].
8255: */
8256: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8257:
8258: /*
8259: ** CAPI3REF: Status Parameters for prepared statements
8260: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8261: **
8262: ** These preprocessor macros define integer codes that name counter
8263: ** values associated with the [sqlite3_stmt_status()] interface.
8264: ** The meanings of the various counters are as follows:
8265: **
8266: ** <dl>
8267: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8268: ** <dd>^This is the number of times that SQLite has stepped forward in
8269: ** a table as part of a full table scan. Large numbers for this counter
1.5 misho 8270: ** may indicate opportunities for performance improvement through
1.2 misho 8271: ** careful use of indices.</dd>
8272: **
8273: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8274: ** <dd>^This is the number of sort operations that have occurred.
8275: ** A non-zero value in this counter may indicate an opportunity to
8276: ** improvement performance through careful use of indices.</dd>
8277: **
8278: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8279: ** <dd>^This is the number of rows inserted into transient indices that
8280: ** were created automatically in order to help joins run faster.
8281: ** A non-zero value in this counter may indicate an opportunity to
8282: ** improvement performance by adding permanent indices that do not
8283: ** need to be reinitialized each time the statement is run.</dd>
1.4 misho 8284: **
8285: ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8286: ** <dd>^This is the number of virtual machine operations executed
8287: ** by the prepared statement if that number is less than or equal
1.5 misho 8288: ** to 2147483647. The number of virtual machine operations can be
1.4 misho 8289: ** used as a proxy for the total work done by the prepared statement.
8290: ** If the number of virtual machine operations exceeds 2147483647
8291: ** then the value returned by this statement status code is undefined.
1.5 misho 8292: **
8293: ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8294: ** <dd>^This is the number of times that the prepare statement has been
8295: ** automatically regenerated due to schema changes or changes to
8296: ** [bound parameters] that might affect the query plan.
8297: **
8298: ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8299: ** <dd>^This is the number of times that the prepared statement has
8300: ** been run. A single "run" for the purposes of this counter is one
8301: ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8302: ** The counter is incremented on the first [sqlite3_step()] call of each
8303: ** cycle.
8304: **
8305: ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8306: ** <dd>^This is the approximate number of bytes of heap memory
8307: ** used to store the prepared statement. ^This value is not actually
8308: ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8309: ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
1.4 misho 8310: ** </dd>
1.2 misho 8311: ** </dl>
8312: */
8313: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8314: #define SQLITE_STMTSTATUS_SORT 2
8315: #define SQLITE_STMTSTATUS_AUTOINDEX 3
1.4 misho 8316: #define SQLITE_STMTSTATUS_VM_STEP 4
1.5 misho 8317: #define SQLITE_STMTSTATUS_REPREPARE 5
8318: #define SQLITE_STMTSTATUS_RUN 6
8319: #define SQLITE_STMTSTATUS_MEMUSED 99
1.2 misho 8320:
8321: /*
8322: ** CAPI3REF: Custom Page Cache Object
8323: **
8324: ** The sqlite3_pcache type is opaque. It is implemented by
8325: ** the pluggable module. The SQLite core has no knowledge of
8326: ** its size or internal structure and never deals with the
8327: ** sqlite3_pcache object except by holding and passing pointers
8328: ** to the object.
8329: **
8330: ** See [sqlite3_pcache_methods2] for additional information.
8331: */
8332: typedef struct sqlite3_pcache sqlite3_pcache;
8333:
8334: /*
8335: ** CAPI3REF: Custom Page Cache Object
8336: **
8337: ** The sqlite3_pcache_page object represents a single page in the
8338: ** page cache. The page cache will allocate instances of this
8339: ** object. Various methods of the page cache use pointers to instances
8340: ** of this object as parameters or as their return value.
8341: **
8342: ** See [sqlite3_pcache_methods2] for additional information.
8343: */
8344: typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8345: struct sqlite3_pcache_page {
8346: void *pBuf; /* The content of the page */
8347: void *pExtra; /* Extra information associated with the page */
8348: };
8349:
8350: /*
8351: ** CAPI3REF: Application Defined Page Cache.
8352: ** KEYWORDS: {page cache}
8353: **
8354: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
1.5 misho 8355: ** register an alternative page cache implementation by passing in an
1.2 misho 8356: ** instance of the sqlite3_pcache_methods2 structure.)^
1.5 misho 8357: ** In many applications, most of the heap memory allocated by
1.2 misho 8358: ** SQLite is used for the page cache.
1.5 misho 8359: ** By implementing a
1.2 misho 8360: ** custom page cache using this API, an application can better control
1.5 misho 8361: ** the amount of memory consumed by SQLite, the way in which
8362: ** that memory is allocated and released, and the policies used to
8363: ** determine exactly which parts of a database file are cached and for
1.2 misho 8364: ** how long.
8365: **
8366: ** The alternative page cache mechanism is an
8367: ** extreme measure that is only needed by the most demanding applications.
8368: ** The built-in page cache is recommended for most uses.
8369: **
8370: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8371: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8372: ** the application may discard the parameter after the call to
8373: ** [sqlite3_config()] returns.)^
8374: **
8375: ** [[the xInit() page cache method]]
1.5 misho 8376: ** ^(The xInit() method is called once for each effective
1.2 misho 8377: ** call to [sqlite3_initialize()])^
8378: ** (usually only once during the lifetime of the process). ^(The xInit()
8379: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
1.5 misho 8380: ** The intent of the xInit() method is to set up global data structures
8381: ** required by the custom page cache implementation.
8382: ** ^(If the xInit() method is NULL, then the
1.2 misho 8383: ** built-in default page cache is used instead of the application defined
8384: ** page cache.)^
8385: **
8386: ** [[the xShutdown() page cache method]]
8387: ** ^The xShutdown() method is called by [sqlite3_shutdown()].
1.5 misho 8388: ** It can be used to clean up
1.2 misho 8389: ** any outstanding resources before process shutdown, if required.
8390: ** ^The xShutdown() method may be NULL.
8391: **
8392: ** ^SQLite automatically serializes calls to the xInit method,
8393: ** so the xInit method need not be threadsafe. ^The
8394: ** xShutdown method is only called from [sqlite3_shutdown()] so it does
8395: ** not need to be threadsafe either. All other methods must be threadsafe
8396: ** in multithreaded applications.
8397: **
8398: ** ^SQLite will never invoke xInit() more than once without an intervening
8399: ** call to xShutdown().
8400: **
8401: ** [[the xCreate() page cache methods]]
8402: ** ^SQLite invokes the xCreate() method to construct a new cache instance.
8403: ** SQLite will typically create one cache instance for each open database file,
8404: ** though this is not guaranteed. ^The
8405: ** first parameter, szPage, is the size in bytes of the pages that must
8406: ** be allocated by the cache. ^szPage will always a power of two. ^The
1.5 misho 8407: ** second parameter szExtra is a number of bytes of extra storage
1.2 misho 8408: ** associated with each page cache entry. ^The szExtra parameter will
8409: ** a number less than 250. SQLite will use the
8410: ** extra szExtra bytes on each page to store metadata about the underlying
8411: ** database page on disk. The value passed into szExtra depends
8412: ** on the SQLite version, the target platform, and how SQLite was compiled.
8413: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8414: ** created will be used to cache database pages of a file stored on disk, or
8415: ** false if it is used for an in-memory database. The cache implementation
8416: ** does not have to do anything special based with the value of bPurgeable;
8417: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8418: ** never invoke xUnpin() except to deliberately delete a page.
8419: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
1.5 misho 8420: ** false will always have the "discard" flag set to true.
1.2 misho 8421: ** ^Hence, a cache created with bPurgeable false will
8422: ** never contain any unpinned pages.
8423: **
8424: ** [[the xCachesize() page cache method]]
8425: ** ^(The xCachesize() method may be called at any time by SQLite to set the
8426: ** suggested maximum cache-size (number of pages stored by) the cache
8427: ** instance passed as the first argument. This is the value configured using
8428: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8429: ** parameter, the implementation is not required to do anything with this
8430: ** value; it is advisory only.
8431: **
8432: ** [[the xPagecount() page cache methods]]
8433: ** The xPagecount() method must return the number of pages currently
8434: ** stored in the cache, both pinned and unpinned.
1.5 misho 8435: **
1.2 misho 8436: ** [[the xFetch() page cache methods]]
1.5 misho 8437: ** The xFetch() method locates a page in the cache and returns a pointer to
1.2 misho 8438: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8439: ** The pBuf element of the returned sqlite3_pcache_page object will be a
1.5 misho 8440: ** pointer to a buffer of szPage bytes used to store the content of a
1.2 misho 8441: ** single database page. The pExtra element of sqlite3_pcache_page will be
8442: ** a pointer to the szExtra bytes of extra storage that SQLite has requested
8443: ** for each entry in the page cache.
8444: **
8445: ** The page to be fetched is determined by the key. ^The minimum key value
8446: ** is 1. After it has been retrieved using xFetch, the page is considered
8447: ** to be "pinned".
8448: **
8449: ** If the requested page is already in the page cache, then the page cache
8450: ** implementation must return a pointer to the page buffer with its content
8451: ** intact. If the requested page is not already in the cache, then the
8452: ** cache implementation should use the value of the createFlag
8453: ** parameter to help it determined what action to take:
8454: **
8455: ** <table border=1 width=85% align=center>
1.4 misho 8456: ** <tr><th> createFlag <th> Behavior when page is not already in cache
1.2 misho 8457: ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8458: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8459: ** Otherwise return NULL.
8460: ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8461: ** NULL if allocating a new page is effectively impossible.
8462: ** </table>
8463: **
8464: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8465: ** will only use a createFlag of 2 after a prior call with a createFlag of 1
1.5 misho 8466: ** failed.)^ In between the xFetch() calls, SQLite may
1.2 misho 8467: ** attempt to unpin one or more cache pages by spilling the content of
8468: ** pinned pages to disk and synching the operating system disk cache.
8469: **
8470: ** [[the xUnpin() page cache method]]
8471: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8472: ** as its second argument. If the third parameter, discard, is non-zero,
8473: ** then the page must be evicted from the cache.
8474: ** ^If the discard parameter is
8475: ** zero, then the page may be discarded or retained at the discretion of
8476: ** page cache implementation. ^The page cache implementation
8477: ** may choose to evict unpinned pages at any time.
8478: **
1.5 misho 8479: ** The cache must not perform any reference counting. A single
8480: ** call to xUnpin() unpins the page regardless of the number of prior calls
1.2 misho 8481: ** to xFetch().
8482: **
8483: ** [[the xRekey() page cache methods]]
8484: ** The xRekey() method is used to change the key value associated with the
8485: ** page passed as the second argument. If the cache
8486: ** previously contains an entry associated with newKey, it must be
8487: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8488: ** to be pinned.
8489: **
8490: ** When SQLite calls the xTruncate() method, the cache must discard all
8491: ** existing cache entries with page numbers (keys) greater than or equal
8492: ** to the value of the iLimit parameter passed to xTruncate(). If any
8493: ** of these pages are pinned, they are implicitly unpinned, meaning that
8494: ** they can be safely discarded.
8495: **
8496: ** [[the xDestroy() page cache method]]
8497: ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8498: ** All resources associated with the specified cache should be freed. ^After
8499: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8500: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8501: ** functions.
8502: **
8503: ** [[the xShrink() page cache method]]
8504: ** ^SQLite invokes the xShrink() method when it wants the page cache to
8505: ** free up as much of heap memory as possible. The page cache implementation
8506: ** is not obligated to free any memory, but well-behaved implementations should
8507: ** do their best.
8508: */
8509: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8510: struct sqlite3_pcache_methods2 {
8511: int iVersion;
8512: void *pArg;
8513: int (*xInit)(void*);
8514: void (*xShutdown)(void*);
8515: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8516: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8517: int (*xPagecount)(sqlite3_pcache*);
8518: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8519: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
1.5 misho 8520: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
1.2 misho 8521: unsigned oldKey, unsigned newKey);
8522: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8523: void (*xDestroy)(sqlite3_pcache*);
8524: void (*xShrink)(sqlite3_pcache*);
8525: };
8526:
8527: /*
8528: ** This is the obsolete pcache_methods object that has now been replaced
8529: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8530: ** retained in the header file for backwards compatibility only.
8531: */
8532: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8533: struct sqlite3_pcache_methods {
8534: void *pArg;
8535: int (*xInit)(void*);
8536: void (*xShutdown)(void*);
8537: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8538: void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8539: int (*xPagecount)(sqlite3_pcache*);
8540: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8541: void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8542: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8543: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8544: void (*xDestroy)(sqlite3_pcache*);
8545: };
8546:
8547:
8548: /*
8549: ** CAPI3REF: Online Backup Object
8550: **
8551: ** The sqlite3_backup object records state information about an ongoing
8552: ** online backup operation. ^The sqlite3_backup object is created by
8553: ** a call to [sqlite3_backup_init()] and is destroyed by a call to
8554: ** [sqlite3_backup_finish()].
8555: **
8556: ** See Also: [Using the SQLite Online Backup API]
8557: */
8558: typedef struct sqlite3_backup sqlite3_backup;
8559:
8560: /*
8561: ** CAPI3REF: Online Backup API.
8562: **
8563: ** The backup API copies the content of one database into another.
8564: ** It is useful either for creating backups of databases or
1.5 misho 8565: ** for copying in-memory databases to or from persistent files.
1.2 misho 8566: **
8567: ** See Also: [Using the SQLite Online Backup API]
8568: **
8569: ** ^SQLite holds a write transaction open on the destination database file
8570: ** for the duration of the backup operation.
8571: ** ^The source database is read-locked only while it is being read;
8572: ** it is not locked continuously for the entire backup operation.
8573: ** ^Thus, the backup may be performed on a live source database without
8574: ** preventing other database connections from
8575: ** reading or writing to the source database while the backup is underway.
1.5 misho 8576: **
8577: ** ^(To perform a backup operation:
1.2 misho 8578: ** <ol>
8579: ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
1.5 misho 8580: ** backup,
8581: ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
1.2 misho 8582: ** the data between the two databases, and finally
1.5 misho 8583: ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8584: ** associated with the backup operation.
1.2 misho 8585: ** </ol>)^
8586: ** There should be exactly one call to sqlite3_backup_finish() for each
8587: ** successful call to sqlite3_backup_init().
8588: **
8589: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8590: **
1.5 misho 8591: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8592: ** [database connection] associated with the destination database
1.2 misho 8593: ** and the database name, respectively.
8594: ** ^The database name is "main" for the main database, "temp" for the
8595: ** temporary database, or the name specified after the AS keyword in
8596: ** an [ATTACH] statement for an attached database.
1.5 misho 8597: ** ^The S and M arguments passed to
1.2 misho 8598: ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8599: ** and database name of the source database, respectively.
8600: ** ^The source and destination [database connections] (parameters S and D)
8601: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8602: ** an error.
8603: **
1.5 misho 8604: ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8605: ** there is already a read or read-write transaction open on the
1.4 misho 8606: ** destination database.
8607: **
1.2 misho 8608: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8609: ** returned and an error code and error message are stored in the
8610: ** destination [database connection] D.
8611: ** ^The error code and message for the failed call to sqlite3_backup_init()
8612: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8613: ** [sqlite3_errmsg16()] functions.
8614: ** ^A successful call to sqlite3_backup_init() returns a pointer to an
8615: ** [sqlite3_backup] object.
8616: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
1.5 misho 8617: ** sqlite3_backup_finish() functions to perform the specified backup
1.2 misho 8618: ** operation.
8619: **
8620: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8621: **
1.5 misho 8622: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
1.2 misho 8623: ** the source and destination databases specified by [sqlite3_backup] object B.
1.5 misho 8624: ** ^If N is negative, all remaining source pages are copied.
1.2 misho 8625: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8626: ** are still more pages to be copied, then the function returns [SQLITE_OK].
8627: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8628: ** from source to destination, then it returns [SQLITE_DONE].
8629: ** ^If an error occurs while running sqlite3_backup_step(B,N),
8630: ** then an [error code] is returned. ^As well as [SQLITE_OK] and
8631: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8632: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8633: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8634: **
8635: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8636: ** <ol>
8637: ** <li> the destination database was opened read-only, or
8638: ** <li> the destination database is using write-ahead-log journaling
8639: ** and the destination and source page sizes differ, or
8640: ** <li> the destination database is an in-memory database and the
8641: ** destination and source page sizes differ.
8642: ** </ol>)^
8643: **
8644: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8645: ** the [sqlite3_busy_handler | busy-handler function]
1.5 misho 8646: ** is invoked (if one is specified). ^If the
8647: ** busy-handler returns non-zero before the lock is available, then
1.2 misho 8648: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8649: ** sqlite3_backup_step() can be retried later. ^If the source
8650: ** [database connection]
8651: ** is being used to write to the source database when sqlite3_backup_step()
8652: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8653: ** case the call to sqlite3_backup_step() can be retried later on. ^(If
8654: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
1.5 misho 8655: ** [SQLITE_READONLY] is returned, then
8656: ** there is no point in retrying the call to sqlite3_backup_step(). These
8657: ** errors are considered fatal.)^ The application must accept
8658: ** that the backup operation has failed and pass the backup operation handle
1.2 misho 8659: ** to the sqlite3_backup_finish() to release associated resources.
8660: **
8661: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
1.5 misho 8662: ** on the destination file. ^The exclusive lock is not released until either
8663: ** sqlite3_backup_finish() is called or the backup operation is complete
1.2 misho 8664: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8665: ** sqlite3_backup_step() obtains a [shared lock] on the source database that
8666: ** lasts for the duration of the sqlite3_backup_step() call.
8667: ** ^Because the source database is not locked between calls to
8668: ** sqlite3_backup_step(), the source database may be modified mid-way
8669: ** through the backup process. ^If the source database is modified by an
8670: ** external process or via a database connection other than the one being
8671: ** used by the backup operation, then the backup will be automatically
1.5 misho 8672: ** restarted by the next call to sqlite3_backup_step(). ^If the source
1.2 misho 8673: ** database is modified by the using the same database connection as is used
8674: ** by the backup operation, then the backup database is automatically
8675: ** updated at the same time.
8676: **
8677: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8678: **
1.5 misho 8679: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
1.2 misho 8680: ** application wishes to abandon the backup operation, the application
8681: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8682: ** ^The sqlite3_backup_finish() interfaces releases all
1.5 misho 8683: ** resources associated with the [sqlite3_backup] object.
1.2 misho 8684: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8685: ** active write-transaction on the destination database is rolled back.
8686: ** The [sqlite3_backup] object is invalid
8687: ** and may not be used following a call to sqlite3_backup_finish().
8688: **
8689: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8690: ** sqlite3_backup_step() errors occurred, regardless or whether or not
8691: ** sqlite3_backup_step() completed.
8692: ** ^If an out-of-memory condition or IO error occurred during any prior
8693: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8694: ** sqlite3_backup_finish() returns the corresponding [error code].
8695: **
8696: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8697: ** is not a permanent error and does not affect the return value of
8698: ** sqlite3_backup_finish().
8699: **
1.4 misho 8700: ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
1.2 misho 8701: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8702: **
1.4 misho 8703: ** ^The sqlite3_backup_remaining() routine returns the number of pages still
8704: ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8705: ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8706: ** in the source database at the conclusion of the most recent
8707: ** sqlite3_backup_step().
8708: ** ^(The values returned by these functions are only updated by
8709: ** sqlite3_backup_step(). If the source database is modified in a way that
8710: ** changes the size of the source database or the number of pages remaining,
8711: ** those changes are not reflected in the output of sqlite3_backup_pagecount()
8712: ** and sqlite3_backup_remaining() until after the next
8713: ** sqlite3_backup_step().)^
1.2 misho 8714: **
8715: ** <b>Concurrent Usage of Database Handles</b>
8716: **
8717: ** ^The source [database connection] may be used by the application for other
8718: ** purposes while a backup operation is underway or being initialized.
8719: ** ^If SQLite is compiled and configured to support threadsafe database
8720: ** connections, then the source database connection may be used concurrently
8721: ** from within other threads.
8722: **
1.5 misho 8723: ** However, the application must guarantee that the destination
8724: ** [database connection] is not passed to any other API (by any thread) after
1.2 misho 8725: ** sqlite3_backup_init() is called and before the corresponding call to
8726: ** sqlite3_backup_finish(). SQLite does not currently check to see
8727: ** if the application incorrectly accesses the destination [database connection]
8728: ** and so no error code is reported, but the operations may malfunction
8729: ** nevertheless. Use of the destination database connection while a
8730: ** backup is in progress might also also cause a mutex deadlock.
8731: **
8732: ** If running in [shared cache mode], the application must
8733: ** guarantee that the shared cache used by the destination database
8734: ** is not accessed while the backup is running. In practice this means
1.5 misho 8735: ** that the application must guarantee that the disk file being
1.2 misho 8736: ** backed up to is not accessed by any connection within the process,
8737: ** not just the specific connection that was passed to sqlite3_backup_init().
8738: **
1.5 misho 8739: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
1.2 misho 8740: ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8741: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8742: ** APIs are not strictly speaking threadsafe. If they are invoked at the
8743: ** same time as another thread is invoking sqlite3_backup_step() it is
8744: ** possible that they return invalid values.
8745: */
8746: SQLITE_API sqlite3_backup *sqlite3_backup_init(
8747: sqlite3 *pDest, /* Destination database handle */
8748: const char *zDestName, /* Destination database name */
8749: sqlite3 *pSource, /* Source database handle */
8750: const char *zSourceName /* Source database name */
8751: );
8752: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8753: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8754: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8755: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8756:
8757: /*
8758: ** CAPI3REF: Unlock Notification
1.4 misho 8759: ** METHOD: sqlite3
1.2 misho 8760: **
8761: ** ^When running in shared-cache mode, a database operation may fail with
8762: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8763: ** individual tables within the shared-cache cannot be obtained. See
1.5 misho 8764: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8765: ** ^This API may be used to register a callback that SQLite will invoke
1.2 misho 8766: ** when the connection currently holding the required lock relinquishes it.
8767: ** ^This API is only available if the library was compiled with the
8768: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8769: **
8770: ** See Also: [Using the SQLite Unlock Notification Feature].
8771: **
8772: ** ^Shared-cache locks are released when a database connection concludes
1.5 misho 8773: ** its current transaction, either by committing it or rolling it back.
1.2 misho 8774: **
8775: ** ^When a connection (known as the blocked connection) fails to obtain a
8776: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8777: ** identity of the database connection (the blocking connection) that
1.5 misho 8778: ** has locked the required resource is stored internally. ^After an
1.2 misho 8779: ** application receives an SQLITE_LOCKED error, it may call the
1.5 misho 8780: ** sqlite3_unlock_notify() method with the blocked connection handle as
1.2 misho 8781: ** the first argument to register for a callback that will be invoked
8782: ** when the blocking connections current transaction is concluded. ^The
8783: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
1.5 misho 8784: ** call that concludes the blocking connection's transaction.
1.2 misho 8785: **
8786: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8787: ** there is a chance that the blocking connection will have already
8788: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8789: ** If this happens, then the specified callback is invoked immediately,
8790: ** from within the call to sqlite3_unlock_notify().)^
8791: **
8792: ** ^If the blocked connection is attempting to obtain a write-lock on a
8793: ** shared-cache table, and more than one other connection currently holds
1.5 misho 8794: ** a read-lock on the same table, then SQLite arbitrarily selects one of
1.2 misho 8795: ** the other connections to use as the blocking connection.
8796: **
1.5 misho 8797: ** ^(There may be at most one unlock-notify callback registered by a
1.2 misho 8798: ** blocked connection. If sqlite3_unlock_notify() is called when the
8799: ** blocked connection already has a registered unlock-notify callback,
8800: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8801: ** called with a NULL pointer as its second argument, then any existing
1.5 misho 8802: ** unlock-notify callback is canceled. ^The blocked connections
1.2 misho 8803: ** unlock-notify callback may also be canceled by closing the blocked
8804: ** connection using [sqlite3_close()].
8805: **
8806: ** The unlock-notify callback is not reentrant. If an application invokes
8807: ** any sqlite3_xxx API functions from within an unlock-notify callback, a
8808: ** crash or deadlock may be the result.
8809: **
8810: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8811: ** returns SQLITE_OK.
8812: **
8813: ** <b>Callback Invocation Details</b>
8814: **
1.5 misho 8815: ** When an unlock-notify callback is registered, the application provides a
1.2 misho 8816: ** single void* pointer that is passed to the callback when it is invoked.
8817: ** However, the signature of the callback function allows SQLite to pass
8818: ** it an array of void* context pointers. The first argument passed to
8819: ** an unlock-notify callback is a pointer to an array of void* pointers,
8820: ** and the second is the number of entries in the array.
8821: **
1.5 misho 8822: ** When a blocking connection's transaction is concluded, there may be
1.2 misho 8823: ** more than one blocked connection that has registered for an unlock-notify
8824: ** callback. ^If two or more such blocked connections have specified the
8825: ** same callback function, then instead of invoking the callback function
8826: ** multiple times, it is invoked once with the set of void* context pointers
8827: ** specified by the blocked connections bundled together into an array.
1.5 misho 8828: ** This gives the application an opportunity to prioritize any actions
1.2 misho 8829: ** related to the set of unblocked database connections.
8830: **
8831: ** <b>Deadlock Detection</b>
8832: **
1.5 misho 8833: ** Assuming that after registering for an unlock-notify callback a
1.2 misho 8834: ** database waits for the callback to be issued before taking any further
8835: ** action (a reasonable assumption), then using this API may cause the
8836: ** application to deadlock. For example, if connection X is waiting for
8837: ** connection Y's transaction to be concluded, and similarly connection
8838: ** Y is waiting on connection X's transaction, then neither connection
8839: ** will proceed and the system may remain deadlocked indefinitely.
8840: **
8841: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8842: ** detection. ^If a given call to sqlite3_unlock_notify() would put the
8843: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8844: ** unlock-notify callback is registered. The system is said to be in
8845: ** a deadlocked state if connection A has registered for an unlock-notify
8846: ** callback on the conclusion of connection B's transaction, and connection
8847: ** B has itself registered for an unlock-notify callback when connection
8848: ** A's transaction is concluded. ^Indirect deadlock is also detected, so
8849: ** the system is also considered to be deadlocked if connection B has
8850: ** registered for an unlock-notify callback on the conclusion of connection
8851: ** C's transaction, where connection C is waiting on connection A. ^Any
8852: ** number of levels of indirection are allowed.
8853: **
8854: ** <b>The "DROP TABLE" Exception</b>
8855: **
1.5 misho 8856: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
1.2 misho 8857: ** always appropriate to call sqlite3_unlock_notify(). There is however,
8858: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8859: ** SQLite checks if there are any currently executing SELECT statements
8860: ** that belong to the same connection. If there are, SQLITE_LOCKED is
8861: ** returned. In this case there is no "blocking connection", so invoking
8862: ** sqlite3_unlock_notify() results in the unlock-notify callback being
8863: ** invoked immediately. If the application then re-attempts the "DROP TABLE"
8864: ** or "DROP INDEX" query, an infinite loop might be the result.
8865: **
8866: ** One way around this problem is to check the extended error code returned
8867: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8868: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
1.5 misho 8869: ** the special "DROP TABLE/INDEX" case, the extended error code is just
1.2 misho 8870: ** SQLITE_LOCKED.)^
8871: */
8872: SQLITE_API int sqlite3_unlock_notify(
8873: sqlite3 *pBlocked, /* Waiting connection */
8874: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8875: void *pNotifyArg /* Argument to pass to xNotify */
8876: );
8877:
8878:
8879: /*
8880: ** CAPI3REF: String Comparison
8881: **
1.3 misho 8882: ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8883: ** and extensions to compare the contents of two buffers containing UTF-8
8884: ** strings in a case-independent fashion, using the same definition of "case
8885: ** independence" that SQLite uses internally when comparing identifiers.
1.2 misho 8886: */
1.3 misho 8887: SQLITE_API int sqlite3_stricmp(const char *, const char *);
1.2 misho 8888: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8889:
8890: /*
1.4 misho 8891: ** CAPI3REF: String Globbing
8892: *
8893: ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8894: ** string X matches the [GLOB] pattern P.
8895: ** ^The definition of [GLOB] pattern matching used in
8896: ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8897: ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8898: ** is case sensitive.
8899: **
8900: ** Note that this routine returns zero on a match and non-zero if the strings
8901: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8902: **
8903: ** See also: [sqlite3_strlike()].
8904: */
8905: SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8906:
8907: /*
8908: ** CAPI3REF: String LIKE Matching
8909: *
8910: ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8911: ** string X matches the [LIKE] pattern P with escape character E.
8912: ** ^The definition of [LIKE] pattern matching used in
8913: ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8914: ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8915: ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8916: ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8917: ** insensitive - equivalent upper and lower case ASCII characters match
8918: ** one another.
8919: **
8920: ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8921: ** only ASCII characters are case folded.
8922: **
8923: ** Note that this routine returns zero on a match and non-zero if the strings
8924: ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8925: **
8926: ** See also: [sqlite3_strglob()].
8927: */
8928: SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8929:
8930: /*
1.2 misho 8931: ** CAPI3REF: Error Logging Interface
8932: **
1.4 misho 8933: ** ^The [sqlite3_log()] interface writes a message into the [error log]
1.2 misho 8934: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8935: ** ^If logging is enabled, the zFormat string and subsequent arguments are
8936: ** used with [sqlite3_snprintf()] to generate the final output string.
8937: **
8938: ** The sqlite3_log() interface is intended for use by extensions such as
8939: ** virtual tables, collating functions, and SQL functions. While there is
8940: ** nothing to prevent an application from calling sqlite3_log(), doing so
8941: ** is considered bad form.
8942: **
8943: ** The zFormat string must not be NULL.
8944: **
8945: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8946: ** will not use dynamically allocated memory. The log message is stored in
8947: ** a fixed-length buffer on the stack. If the log message is longer than
8948: ** a few hundred characters, it will be truncated to the length of the
8949: ** buffer.
8950: */
8951: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8952:
8953: /*
8954: ** CAPI3REF: Write-Ahead Log Commit Hook
1.4 misho 8955: ** METHOD: sqlite3
1.2 misho 8956: **
8957: ** ^The [sqlite3_wal_hook()] function is used to register a callback that
1.4 misho 8958: ** is invoked each time data is committed to a database in wal mode.
1.2 misho 8959: **
1.5 misho 8960: ** ^(The callback is invoked by SQLite after the commit has taken place and
8961: ** the associated write-lock on the database released)^, so the implementation
1.2 misho 8962: ** may read, write or [checkpoint] the database as required.
8963: **
8964: ** ^The first parameter passed to the callback function when it is invoked
8965: ** is a copy of the third parameter passed to sqlite3_wal_hook() when
8966: ** registering the callback. ^The second is a copy of the database handle.
8967: ** ^The third parameter is the name of the database that was written to -
8968: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8969: ** is the number of pages currently in the write-ahead log file,
8970: ** including those that were just committed.
8971: **
8972: ** The callback function should normally return [SQLITE_OK]. ^If an error
8973: ** code is returned, that error will propagate back up through the
8974: ** SQLite code base to cause the statement that provoked the callback
8975: ** to report an error, though the commit will have still occurred. If the
8976: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8977: ** that does not correspond to any valid SQLite error code, the results
8978: ** are undefined.
8979: **
1.5 misho 8980: ** A single database handle may have at most a single write-ahead log callback
1.2 misho 8981: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8982: ** previously registered write-ahead log callback. ^Note that the
8983: ** [sqlite3_wal_autocheckpoint()] interface and the
8984: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
1.4 misho 8985: ** overwrite any prior [sqlite3_wal_hook()] settings.
1.2 misho 8986: */
8987: SQLITE_API void *sqlite3_wal_hook(
1.5 misho 8988: sqlite3*,
1.2 misho 8989: int(*)(void *,sqlite3*,const char*,int),
8990: void*
8991: );
8992:
8993: /*
8994: ** CAPI3REF: Configure an auto-checkpoint
1.4 misho 8995: ** METHOD: sqlite3
1.2 misho 8996: **
8997: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8998: ** [sqlite3_wal_hook()] that causes any database on [database connection] D
8999: ** to automatically [checkpoint]
9000: ** after committing a transaction if there are N or
1.5 misho 9001: ** more frames in the [write-ahead log] file. ^Passing zero or
1.2 misho 9002: ** a negative value as the nFrame parameter disables automatic
9003: ** checkpoints entirely.
9004: **
9005: ** ^The callback registered by this function replaces any existing callback
9006: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9007: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9008: ** configured by this function.
9009: **
9010: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9011: ** from SQL.
9012: **
1.4 misho 9013: ** ^Checkpoints initiated by this mechanism are
9014: ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9015: **
1.2 misho 9016: ** ^Every new [database connection] defaults to having the auto-checkpoint
9017: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9018: ** pages. The use of this interface
9019: ** is only necessary if the default setting is found to be suboptimal
9020: ** for a particular application.
9021: */
9022: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9023:
9024: /*
9025: ** CAPI3REF: Checkpoint a database
1.4 misho 9026: ** METHOD: sqlite3
1.2 misho 9027: **
1.4 misho 9028: ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9029: ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
1.2 misho 9030: **
1.5 misho 9031: ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
1.4 misho 9032: ** [write-ahead log] for database X on [database connection] D to be
9033: ** transferred into the database file and for the write-ahead log to
9034: ** be reset. See the [checkpointing] documentation for addition
9035: ** information.
9036: **
9037: ** This interface used to be the only way to cause a checkpoint to
9038: ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9039: ** interface was added. This interface is retained for backwards
9040: ** compatibility and as a convenience for applications that need to manually
9041: ** start a callback but which do not need the full power (and corresponding
9042: ** complication) of [sqlite3_wal_checkpoint_v2()].
1.2 misho 9043: */
9044: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9045:
9046: /*
9047: ** CAPI3REF: Checkpoint a database
1.4 misho 9048: ** METHOD: sqlite3
1.2 misho 9049: **
1.4 misho 9050: ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9051: ** operation on database X of [database connection] D in mode M. Status
9052: ** information is written back into integers pointed to by L and C.)^
9053: ** ^(The M parameter must be a valid [checkpoint mode]:)^
1.2 misho 9054: **
9055: ** <dl>
9056: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
1.5 misho 9057: ** ^Checkpoint as many frames as possible without waiting for any database
9058: ** readers or writers to finish, then sync the database file if all frames
1.4 misho 9059: ** in the log were checkpointed. ^The [busy-handler callback]
1.5 misho 9060: ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
1.4 misho 9061: ** ^On the other hand, passive mode might leave the checkpoint unfinished
9062: ** if there are concurrent readers or writers.
1.2 misho 9063: **
9064: ** <dt>SQLITE_CHECKPOINT_FULL<dd>
1.4 misho 9065: ** ^This mode blocks (it invokes the
9066: ** [sqlite3_busy_handler|busy-handler callback]) until there is no
1.2 misho 9067: ** database writer and all readers are reading from the most recent database
1.4 misho 9068: ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9069: ** database file. ^This mode blocks new database writers while it is pending,
9070: ** but new database readers are allowed to continue unimpeded.
1.2 misho 9071: **
9072: ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
1.4 misho 9073: ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
1.5 misho 9074: ** that after checkpointing the log file it blocks (calls the
1.4 misho 9075: ** [busy-handler callback])
1.5 misho 9076: ** until all readers are reading from the database file only. ^This ensures
1.4 misho 9077: ** that the next writer will restart the log file from the beginning.
9078: ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9079: ** database writer attempts while it is pending, but does not impede readers.
9080: **
9081: ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9082: ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9083: ** addition that it also truncates the log file to zero bytes just prior
9084: ** to a successful return.
1.2 misho 9085: ** </dl>
9086: **
1.4 misho 9087: ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9088: ** the log file or to -1 if the checkpoint could not run because
9089: ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9090: ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9091: ** log file (including any that were already checkpointed before the function
9092: ** was called) or to -1 if the checkpoint could not run due to an error or
9093: ** because the database is not in WAL mode. ^Note that upon successful
9094: ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9095: ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
1.2 misho 9096: **
1.4 misho 9097: ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
1.5 misho 9098: ** any other process is running a checkpoint operation at the same time, the
9099: ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
1.2 misho 9100: ** busy-handler configured, it will not be invoked in this case.
9101: **
1.5 misho 9102: ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
1.4 misho 9103: ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9104: ** obtained immediately, and a busy-handler is configured, it is invoked and
9105: ** the writer lock retried until either the busy-handler returns 0 or the lock
9106: ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9107: ** database readers as described above. ^If the busy-handler returns 0 before
1.2 misho 9108: ** the writer lock is obtained or while waiting for database readers, the
1.5 misho 9109: ** checkpoint operation proceeds from that point in the same way as
9110: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
1.4 misho 9111: ** without blocking any further. ^SQLITE_BUSY is returned in this case.
1.2 misho 9112: **
1.4 misho 9113: ** ^If parameter zDb is NULL or points to a zero length string, then the
1.5 misho 9114: ** specified operation is attempted on all WAL databases [attached] to
1.4 misho 9115: ** [database connection] db. In this case the
1.5 misho 9116: ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9117: ** an SQLITE_BUSY error is encountered when processing one or more of the
9118: ** attached WAL databases, the operation is still attempted on any remaining
9119: ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9120: ** error occurs while processing an attached database, processing is abandoned
9121: ** and the error code is returned to the caller immediately. ^If no error
9122: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
1.2 misho 9123: ** databases, SQLITE_OK is returned.
9124: **
1.4 misho 9125: ** ^If database zDb is the name of an attached database that is not in WAL
9126: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
1.2 misho 9127: ** zDb is not NULL (or a zero length string) and is not the name of any
9128: ** attached database, SQLITE_ERROR is returned to the caller.
1.4 misho 9129: **
9130: ** ^Unless it returns SQLITE_MISUSE,
9131: ** the sqlite3_wal_checkpoint_v2() interface
9132: ** sets the error information that is queried by
9133: ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9134: **
9135: ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9136: ** from SQL.
1.2 misho 9137: */
9138: SQLITE_API int sqlite3_wal_checkpoint_v2(
9139: sqlite3 *db, /* Database handle */
9140: const char *zDb, /* Name of attached database (or NULL) */
9141: int eMode, /* SQLITE_CHECKPOINT_* value */
9142: int *pnLog, /* OUT: Size of WAL log in frames */
9143: int *pnCkpt /* OUT: Total number of frames checkpointed */
9144: );
9145:
9146: /*
1.4 misho 9147: ** CAPI3REF: Checkpoint Mode Values
9148: ** KEYWORDS: {checkpoint mode}
1.2 misho 9149: **
1.4 misho 9150: ** These constants define all valid values for the "checkpoint mode" passed
9151: ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9152: ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9153: ** meaning of each of these checkpoint modes.
9154: */
9155: #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9156: #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9157: #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9158: #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
1.2 misho 9159:
9160: /*
9161: ** CAPI3REF: Virtual Table Interface Configuration
9162: **
9163: ** This function may be called by either the [xConnect] or [xCreate] method
9164: ** of a [virtual table] implementation to configure
9165: ** various facets of the virtual table interface.
9166: **
9167: ** If this interface is invoked outside the context of an xConnect or
9168: ** xCreate virtual table method then the behavior is undefined.
9169: **
1.5 misho 9170: ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9171: ** [database connection] in which the virtual table is being created and
9172: ** which is passed in as the first argument to the [xConnect] or [xCreate]
9173: ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9174: ** of the [virtual table configuration options]. The presence and meaning
9175: ** of parameters after C depend on which [virtual table configuration option]
9176: ** is used.
1.2 misho 9177: */
9178: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9179:
9180: /*
9181: ** CAPI3REF: Virtual Table Configuration Options
1.5 misho 9182: ** KEYWORDS: {virtual table configuration options}
9183: ** KEYWORDS: {virtual table configuration option}
1.2 misho 9184: **
9185: ** These macros define the various options to the
9186: ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9187: ** can use to customize and optimize their behavior.
9188: **
9189: ** <dl>
1.5 misho 9190: ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9191: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
1.2 misho 9192: ** <dd>Calls of the form
9193: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9194: ** where X is an integer. If X is zero, then the [virtual table] whose
9195: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9196: ** support constraints. In this configuration (which is the default) if
9197: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9198: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9199: ** specified as part of the users SQL statement, regardless of the actual
9200: ** ON CONFLICT mode specified.
9201: **
9202: ** If X is non-zero, then the virtual table implementation guarantees
9203: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9204: ** any modifications to internal or persistent data structures have been made.
1.5 misho 9205: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
1.2 misho 9206: ** is able to roll back a statement or database transaction, and abandon
1.5 misho 9207: ** or continue processing the current SQL statement as appropriate.
1.2 misho 9208: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9209: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9210: ** had been ABORT.
9211: **
9212: ** Virtual table implementations that are required to handle OR REPLACE
1.5 misho 9213: ** must do so within the [xUpdate] method. If a call to the
9214: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9215: ** CONFLICT policy is REPLACE, the virtual table implementation should
1.2 misho 9216: ** silently replace the appropriate rows within the xUpdate callback and
9217: ** return SQLITE_OK. Or, if this is not possible, it may return
1.5 misho 9218: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
1.2 misho 9219: ** constraint handling.
1.5 misho 9220: ** </dd>
9221: **
9222: ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9223: ** <dd>Calls of the form
9224: ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9225: ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9226: ** prohibits that virtual table from being used from within triggers and
9227: ** views.
9228: ** </dd>
9229: **
9230: ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9231: ** <dd>Calls of the form
9232: ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9233: ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9234: ** identify that virtual table as being safe to use from within triggers
9235: ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9236: ** virtual table can do no serious harm even if it is controlled by a
9237: ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9238: ** flag unless absolutely necessary.
9239: ** </dd>
1.2 misho 9240: ** </dl>
9241: */
9242: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
1.5 misho 9243: #define SQLITE_VTAB_INNOCUOUS 2
9244: #define SQLITE_VTAB_DIRECTONLY 3
1.2 misho 9245:
9246: /*
9247: ** CAPI3REF: Determine The Virtual Table Conflict Policy
9248: **
9249: ** This function may only be called from within a call to the [xUpdate] method
9250: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9251: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9252: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9253: ** of the SQL statement that triggered the call to the [xUpdate] method of the
9254: ** [virtual table].
9255: */
9256: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9257:
9258: /*
1.5 misho 9259: ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9260: **
9261: ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
1.6 ! misho 9262: ** method of a [virtual table], then it might return true if the
1.5 misho 9263: ** column is being fetched as part of an UPDATE operation during which the
1.6 ! misho 9264: ** column value will not change. The virtual table implementation can use
! 9265: ** this hint as permission to substitute a return value that is less
! 9266: ** expensive to compute and that the corresponding
1.5 misho 9267: ** [xUpdate] method understands as a "no-change" value.
9268: **
9269: ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9270: ** the column is not changed by the UPDATE statement, then the xColumn
9271: ** method can optionally return without setting a result, without calling
9272: ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9273: ** In that case, [sqlite3_value_nochange(X)] will return true for the
9274: ** same column in the [xUpdate] method.
1.6 ! misho 9275: **
! 9276: ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
! 9277: ** implementations should continue to give a correct answer even if the
! 9278: ** sqlite3_vtab_nochange() interface were to always return false. In the
! 9279: ** current implementation, the sqlite3_vtab_nochange() interface does always
! 9280: ** returns false for the enhanced [UPDATE FROM] statement.
1.5 misho 9281: */
9282: SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9283:
9284: /*
9285: ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9286: **
9287: ** This function may only be called from within a call to the [xBestIndex]
9288: ** method of a [virtual table].
9289: **
9290: ** The first argument must be the sqlite3_index_info object that is the
9291: ** first parameter to the xBestIndex() method. The second argument must be
9292: ** an index into the aConstraint[] array belonging to the sqlite3_index_info
9293: ** structure passed to xBestIndex. This function returns a pointer to a buffer
9294: ** containing the name of the collation sequence for the corresponding
9295: ** constraint.
9296: */
9297: SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9298:
9299: /*
1.2 misho 9300: ** CAPI3REF: Conflict resolution modes
1.4 misho 9301: ** KEYWORDS: {conflict resolution mode}
1.2 misho 9302: **
9303: ** These constants are returned by [sqlite3_vtab_on_conflict()] to
9304: ** inform a [virtual table] implementation what the [ON CONFLICT] mode
9305: ** is for the SQL statement being evaluated.
9306: **
9307: ** Note that the [SQLITE_IGNORE] constant is also used as a potential
9308: ** return value from the [sqlite3_set_authorizer()] callback and that
9309: ** [SQLITE_ABORT] is also a [result code].
9310: */
9311: #define SQLITE_ROLLBACK 1
9312: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9313: #define SQLITE_FAIL 3
9314: /* #define SQLITE_ABORT 4 // Also an error code */
9315: #define SQLITE_REPLACE 5
9316:
1.4 misho 9317: /*
9318: ** CAPI3REF: Prepared Statement Scan Status Opcodes
9319: ** KEYWORDS: {scanstatus options}
9320: **
9321: ** The following constants can be used for the T parameter to the
9322: ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9323: ** different metric for sqlite3_stmt_scanstatus() to return.
9324: **
9325: ** When the value returned to V is a string, space to hold that string is
9326: ** managed by the prepared statement S and will be automatically freed when
9327: ** S is finalized.
9328: **
9329: ** <dl>
9330: ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
1.5 misho 9331: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
1.4 misho 9332: ** set to the total number of times that the X-th loop has run.</dd>
9333: **
9334: ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
1.5 misho 9335: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
1.4 misho 9336: ** to the total number of rows examined by all iterations of the X-th loop.</dd>
9337: **
9338: ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
1.5 misho 9339: ** <dd>^The "double" variable pointed to by the V parameter will be set to the
1.4 misho 9340: ** query planner's estimate for the average number of rows output from each
9341: ** iteration of the X-th loop. If the query planner's estimates was accurate,
9342: ** then this value will approximate the quotient NVISIT/NLOOP and the
9343: ** product of this value for all prior loops with the same SELECTID will
9344: ** be the NLOOP value for the current loop.
9345: **
9346: ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
1.5 misho 9347: ** <dd>^The "const char *" variable pointed to by the V parameter will be set
1.4 misho 9348: ** to a zero-terminated UTF-8 string containing the name of the index or table
9349: ** used for the X-th loop.
9350: **
9351: ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
1.5 misho 9352: ** <dd>^The "const char *" variable pointed to by the V parameter will be set
1.4 misho 9353: ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9354: ** description for the X-th loop.
9355: **
9356: ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
1.5 misho 9357: ** <dd>^The "int" variable pointed to by the V parameter will be set to the
1.4 misho 9358: ** "select-id" for the X-th loop. The select-id identifies which query or
9359: ** subquery the loop is part of. The main query has a select-id of zero.
9360: ** The select-id is the same value as is output in the first column
9361: ** of an [EXPLAIN QUERY PLAN] query.
9362: ** </dl>
9363: */
9364: #define SQLITE_SCANSTAT_NLOOP 0
9365: #define SQLITE_SCANSTAT_NVISIT 1
9366: #define SQLITE_SCANSTAT_EST 2
9367: #define SQLITE_SCANSTAT_NAME 3
9368: #define SQLITE_SCANSTAT_EXPLAIN 4
9369: #define SQLITE_SCANSTAT_SELECTID 5
9370:
9371: /*
9372: ** CAPI3REF: Prepared Statement Scan Status
9373: ** METHOD: sqlite3_stmt
9374: **
9375: ** This interface returns information about the predicted and measured
9376: ** performance for pStmt. Advanced applications can use this
9377: ** interface to compare the predicted and the measured performance and
9378: ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9379: **
9380: ** Since this interface is expected to be rarely used, it is only
9381: ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9382: ** compile-time option.
9383: **
9384: ** The "iScanStatusOp" parameter determines which status information to return.
9385: ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9386: ** of this interface is undefined.
9387: ** ^The requested measurement is written into a variable pointed to by
9388: ** the "pOut" parameter.
9389: ** Parameter "idx" identifies the specific loop to retrieve statistics for.
9390: ** Loops are numbered starting from zero. ^If idx is out of range - less than
9391: ** zero or greater than or equal to the total number of loops used to implement
9392: ** the statement - a non-zero value is returned and the variable that pOut
9393: ** points to is unchanged.
9394: **
9395: ** ^Statistics might not be available for all loops in all statements. ^In cases
9396: ** where there exist loops with no available statistics, this function behaves
9397: ** as if the loop did not exist - it returns non-zero and leave the variable
9398: ** that pOut points to unchanged.
9399: **
9400: ** See also: [sqlite3_stmt_scanstatus_reset()]
9401: */
9402: SQLITE_API int sqlite3_stmt_scanstatus(
9403: sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9404: int idx, /* Index of loop to report on */
9405: int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9406: void *pOut /* Result written here */
1.5 misho 9407: );
1.4 misho 9408:
9409: /*
9410: ** CAPI3REF: Zero Scan-Status Counters
9411: ** METHOD: sqlite3_stmt
9412: **
9413: ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9414: **
9415: ** This API is only available if the library is built with pre-processor
9416: ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9417: */
9418: SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9419:
9420: /*
9421: ** CAPI3REF: Flush caches to disk mid-transaction
1.6 ! misho 9422: ** METHOD: sqlite3
1.4 misho 9423: **
9424: ** ^If a write-transaction is open on [database connection] D when the
9425: ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
1.5 misho 9426: ** pages in the pager-cache that are not currently in use are written out
1.4 misho 9427: ** to disk. A dirty page may be in use if a database cursor created by an
9428: ** active SQL statement is reading from it, or if it is page 1 of a database
9429: ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9430: ** interface flushes caches for all schemas - "main", "temp", and
9431: ** any [attached] databases.
9432: **
1.5 misho 9433: ** ^If this function needs to obtain extra database locks before dirty pages
9434: ** can be flushed to disk, it does so. ^If those locks cannot be obtained
1.4 misho 9435: ** immediately and there is a busy-handler callback configured, it is invoked
9436: ** in the usual manner. ^If the required lock still cannot be obtained, then
9437: ** the database is skipped and an attempt made to flush any dirty pages
9438: ** belonging to the next (if any) database. ^If any databases are skipped
9439: ** because locks cannot be obtained, but no other error occurs, this
9440: ** function returns SQLITE_BUSY.
9441: **
9442: ** ^If any other error occurs while flushing dirty pages to disk (for
9443: ** example an IO error or out-of-memory condition), then processing is
9444: ** abandoned and an SQLite [error code] is returned to the caller immediately.
9445: **
9446: ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9447: **
9448: ** ^This function does not set the database handle error code or message
9449: ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9450: */
9451: SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9452:
9453: /*
9454: ** CAPI3REF: The pre-update hook.
1.6 ! misho 9455: ** METHOD: sqlite3
1.4 misho 9456: **
9457: ** ^These interfaces are only available if SQLite is compiled using the
9458: ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9459: **
9460: ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9461: ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
1.5 misho 9462: ** on a database table.
1.4 misho 9463: ** ^At most one preupdate hook may be registered at a time on a single
9464: ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9465: ** the previous setting.
9466: ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9467: ** with a NULL pointer as the second parameter.
9468: ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9469: ** the first parameter to callbacks.
9470: **
1.5 misho 9471: ** ^The preupdate hook only fires for changes to real database tables; the
9472: ** preupdate hook is not invoked for changes to [virtual tables] or to
9473: ** system tables like sqlite_sequence or sqlite_stat1.
1.4 misho 9474: **
9475: ** ^The second parameter to the preupdate callback is a pointer to
9476: ** the [database connection] that registered the preupdate hook.
9477: ** ^The third parameter to the preupdate callback is one of the constants
9478: ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9479: ** kind of update operation that is about to occur.
9480: ** ^(The fourth parameter to the preupdate callback is the name of the
9481: ** database within the database connection that is being modified. This
1.5 misho 9482: ** will be "main" for the main database or "temp" for TEMP tables or
1.4 misho 9483: ** the name given after the AS keyword in the [ATTACH] statement for attached
9484: ** databases.)^
9485: ** ^The fifth parameter to the preupdate callback is the name of the
9486: ** table that is being modified.
1.5 misho 9487: **
9488: ** For an UPDATE or DELETE operation on a [rowid table], the sixth
9489: ** parameter passed to the preupdate callback is the initial [rowid] of the
9490: ** row being modified or deleted. For an INSERT operation on a rowid table,
9491: ** or any operation on a WITHOUT ROWID table, the value of the sixth
9492: ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
9493: ** seventh parameter is the final rowid value of the row being inserted
9494: ** or updated. The value of the seventh parameter passed to the callback
9495: ** function is not defined for operations on WITHOUT ROWID tables, or for
1.6 ! misho 9496: ** DELETE operations on rowid tables.
1.4 misho 9497: **
9498: ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9499: ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9500: ** provide additional information about a preupdate event. These routines
9501: ** may only be called from within a preupdate callback. Invoking any of
9502: ** these routines from outside of a preupdate callback or with a
9503: ** [database connection] pointer that is different from the one supplied
9504: ** to the preupdate callback results in undefined and probably undesirable
9505: ** behavior.
9506: **
9507: ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9508: ** in the row that is being inserted, updated, or deleted.
9509: **
9510: ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9511: ** a [protected sqlite3_value] that contains the value of the Nth column of
9512: ** the table row before it is updated. The N parameter must be between 0
9513: ** and one less than the number of columns or the behavior will be
9514: ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9515: ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9516: ** behavior is undefined. The [sqlite3_value] that P points to
9517: ** will be destroyed when the preupdate callback returns.
9518: **
9519: ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9520: ** a [protected sqlite3_value] that contains the value of the Nth column of
9521: ** the table row after it is updated. The N parameter must be between 0
9522: ** and one less than the number of columns or the behavior will be
9523: ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9524: ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9525: ** behavior is undefined. The [sqlite3_value] that P points to
9526: ** will be destroyed when the preupdate callback returns.
9527: **
9528: ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9529: ** callback was invoked as a result of a direct insert, update, or delete
1.5 misho 9530: ** operation; or 1 for inserts, updates, or deletes invoked by top-level
1.4 misho 9531: ** triggers; or 2 for changes resulting from triggers called by top-level
9532: ** triggers; and so forth.
9533: **
9534: ** See also: [sqlite3_update_hook()]
9535: */
1.5 misho 9536: #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9537: SQLITE_API void *sqlite3_preupdate_hook(
1.4 misho 9538: sqlite3 *db,
9539: void(*xPreUpdate)(
9540: void *pCtx, /* Copy of third arg to preupdate_hook() */
9541: sqlite3 *db, /* Database handle */
9542: int op, /* SQLITE_UPDATE, DELETE or INSERT */
9543: char const *zDb, /* Database name */
9544: char const *zName, /* Table name */
9545: sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9546: sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9547: ),
9548: void*
9549: );
1.5 misho 9550: SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9551: SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9552: SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9553: SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9554: #endif
1.4 misho 9555:
9556: /*
9557: ** CAPI3REF: Low-level system error code
1.6 ! misho 9558: ** METHOD: sqlite3
1.4 misho 9559: **
9560: ** ^Attempt to return the underlying operating system error code or error
9561: ** number that caused the most recent I/O error or failure to open a file.
9562: ** The return value is OS-dependent. For example, on unix systems, after
9563: ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9564: ** called to get back the underlying "errno" that caused the problem, such
1.5 misho 9565: ** as ENOSPC, EAUTH, EISDIR, and so forth.
1.4 misho 9566: */
9567: SQLITE_API int sqlite3_system_errno(sqlite3*);
9568:
9569: /*
9570: ** CAPI3REF: Database Snapshot
1.5 misho 9571: ** KEYWORDS: {snapshot} {sqlite3_snapshot}
1.4 misho 9572: **
9573: ** An instance of the snapshot object records the state of a [WAL mode]
9574: ** database for some specific point in history.
9575: **
9576: ** In [WAL mode], multiple [database connections] that are open on the
9577: ** same database file can each be reading a different historical version
9578: ** of the database file. When a [database connection] begins a read
9579: ** transaction, that connection sees an unchanging copy of the database
9580: ** as it existed for the point in time when the transaction first started.
9581: ** Subsequent changes to the database from other connections are not seen
9582: ** by the reader until a new read transaction is started.
9583: **
9584: ** The sqlite3_snapshot object records state information about an historical
9585: ** version of the database file so that it is possible to later open a new read
9586: ** transaction that sees that historical version of the database rather than
9587: ** the most recent version.
9588: */
1.5 misho 9589: typedef struct sqlite3_snapshot {
9590: unsigned char hidden[48];
9591: } sqlite3_snapshot;
1.4 misho 9592:
9593: /*
9594: ** CAPI3REF: Record A Database Snapshot
1.5 misho 9595: ** CONSTRUCTOR: sqlite3_snapshot
1.4 misho 9596: **
9597: ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9598: ** new [sqlite3_snapshot] object that records the current state of
9599: ** schema S in database connection D. ^On success, the
9600: ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9601: ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
1.5 misho 9602: ** If there is not already a read-transaction open on schema S when
9603: ** this function is called, one is opened automatically.
9604: **
9605: ** The following must be true for this function to succeed. If any of
9606: ** the following statements are false when sqlite3_snapshot_get() is
9607: ** called, SQLITE_ERROR is returned. The final value of *P is undefined
9608: ** in this case.
9609: **
9610: ** <ul>
9611: ** <li> The database handle must not be in [autocommit mode].
9612: **
9613: ** <li> Schema S of [database connection] D must be a [WAL mode] database.
9614: **
9615: ** <li> There must not be a write transaction open on schema S of database
9616: ** connection D.
9617: **
9618: ** <li> One or more transactions must have been written to the current wal
9619: ** file since it was created on disk (by any connection). This means
9620: ** that a snapshot cannot be taken on a wal mode database with no wal
9621: ** file immediately after it is first opened. At least one transaction
9622: ** must be written to it first.
9623: ** </ul>
9624: **
9625: ** This function may also return SQLITE_NOMEM. If it is called with the
9626: ** database handle in autocommit mode but fails for some other reason,
9627: ** whether or not a read transaction is opened on schema S is undefined.
1.4 misho 9628: **
9629: ** The [sqlite3_snapshot] object returned from a successful call to
9630: ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9631: ** to avoid a memory leak.
9632: **
9633: ** The [sqlite3_snapshot_get()] interface is only available when the
1.5 misho 9634: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
1.4 misho 9635: */
9636: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9637: sqlite3 *db,
9638: const char *zSchema,
9639: sqlite3_snapshot **ppSnapshot
9640: );
9641:
9642: /*
9643: ** CAPI3REF: Start a read transaction on an historical snapshot
1.5 misho 9644: ** METHOD: sqlite3_snapshot
9645: **
9646: ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9647: ** transaction or upgrades an existing one for schema S of
9648: ** [database connection] D such that the read transaction refers to
9649: ** historical [snapshot] P, rather than the most recent change to the
9650: ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9651: ** on success or an appropriate [error code] if it fails.
9652: **
9653: ** ^In order to succeed, the database connection must not be in
9654: ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9655: ** is already a read transaction open on schema S, then the database handle
9656: ** must have no active statements (SELECT statements that have been passed
9657: ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9658: ** SQLITE_ERROR is returned if either of these conditions is violated, or
9659: ** if schema S does not exist, or if the snapshot object is invalid.
9660: **
9661: ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9662: ** snapshot has been overwritten by a [checkpoint]. In this case
9663: ** SQLITE_ERROR_SNAPSHOT is returned.
9664: **
9665: ** If there is already a read transaction open when this function is
9666: ** invoked, then the same read transaction remains open (on the same
9667: ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9668: ** is returned. If another error code - for example SQLITE_PROTOCOL or an
9669: ** SQLITE_IOERR error code - is returned, then the final state of the
9670: ** read transaction is undefined. If SQLITE_OK is returned, then the
9671: ** read transaction is now open on database snapshot P.
1.4 misho 9672: **
9673: ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9674: ** database connection D does not know that the database file for
9675: ** schema S is in [WAL mode]. A database connection might not know
9676: ** that the database file is in [WAL mode] if there has been no prior
1.5 misho 9677: ** I/O on that database connection, or if the database entered [WAL mode]
1.4 misho 9678: ** after the most recent I/O on the database connection.)^
9679: ** (Hint: Run "[PRAGMA application_id]" against a newly opened
9680: ** database connection in order to make it ready to use snapshots.)
9681: **
9682: ** The [sqlite3_snapshot_open()] interface is only available when the
1.5 misho 9683: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
1.4 misho 9684: */
9685: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9686: sqlite3 *db,
9687: const char *zSchema,
9688: sqlite3_snapshot *pSnapshot
9689: );
9690:
9691: /*
9692: ** CAPI3REF: Destroy a snapshot
1.5 misho 9693: ** DESTRUCTOR: sqlite3_snapshot
1.4 misho 9694: **
9695: ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9696: ** The application must eventually free every [sqlite3_snapshot] object
9697: ** using this routine to avoid a memory leak.
9698: **
9699: ** The [sqlite3_snapshot_free()] interface is only available when the
1.5 misho 9700: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
1.4 misho 9701: */
9702: SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
1.2 misho 9703:
1.4 misho 9704: /*
9705: ** CAPI3REF: Compare the ages of two snapshot handles.
1.5 misho 9706: ** METHOD: sqlite3_snapshot
1.4 misho 9707: **
9708: ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
1.5 misho 9709: ** of two valid snapshot handles.
1.4 misho 9710: **
1.5 misho 9711: ** If the two snapshot handles are not associated with the same database
9712: ** file, the result of the comparison is undefined.
1.4 misho 9713: **
9714: ** Additionally, the result of the comparison is only valid if both of the
9715: ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9716: ** last time the wal file was deleted. The wal file is deleted when the
9717: ** database is changed back to rollback mode or when the number of database
1.5 misho 9718: ** clients drops to zero. If either snapshot handle was obtained before the
9719: ** wal file was last deleted, the value returned by this function
1.4 misho 9720: ** is undefined.
9721: **
9722: ** Otherwise, this API returns a negative value if P1 refers to an older
9723: ** snapshot than P2, zero if the two handles refer to the same database
9724: ** snapshot, and a positive value if P1 is a newer snapshot than P2.
1.5 misho 9725: **
9726: ** This interface is only available if SQLite is compiled with the
9727: ** [SQLITE_ENABLE_SNAPSHOT] option.
1.4 misho 9728: */
9729: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9730: sqlite3_snapshot *p1,
9731: sqlite3_snapshot *p2
9732: );
1.2 misho 9733:
9734: /*
1.5 misho 9735: ** CAPI3REF: Recover snapshots from a wal file
9736: ** METHOD: sqlite3_snapshot
9737: **
9738: ** If a [WAL file] remains on disk after all database connections close
9739: ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9740: ** or because the last process to have the database opened exited without
9741: ** calling [sqlite3_close()]) and a new connection is subsequently opened
9742: ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9743: ** will only be able to open the last transaction added to the WAL file
9744: ** even though the WAL file contains other valid transactions.
9745: **
9746: ** This function attempts to scan the WAL file associated with database zDb
9747: ** of database handle db and make all valid snapshots available to
9748: ** sqlite3_snapshot_open(). It is an error if there is already a read
9749: ** transaction open on the database, or if the database is not a WAL mode
9750: ** database.
9751: **
9752: ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9753: **
9754: ** This interface is only available if SQLite is compiled with the
9755: ** [SQLITE_ENABLE_SNAPSHOT] option.
9756: */
9757: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9758:
9759: /*
9760: ** CAPI3REF: Serialize a database
9761: **
9762: ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9763: ** that is a serialization of the S database on [database connection] D.
9764: ** If P is not a NULL pointer, then the size of the database in bytes
9765: ** is written into *P.
9766: **
9767: ** For an ordinary on-disk database file, the serialization is just a
9768: ** copy of the disk file. For an in-memory database or a "TEMP" database,
9769: ** the serialization is the same sequence of bytes which would be written
9770: ** to disk if that database where backed up to disk.
9771: **
9772: ** The usual case is that sqlite3_serialize() copies the serialization of
9773: ** the database into memory obtained from [sqlite3_malloc64()] and returns
9774: ** a pointer to that memory. The caller is responsible for freeing the
9775: ** returned value to avoid a memory leak. However, if the F argument
9776: ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9777: ** are made, and the sqlite3_serialize() function will return a pointer
9778: ** to the contiguous memory representation of the database that SQLite
9779: ** is currently using for that database, or NULL if the no such contiguous
9780: ** memory representation of the database exists. A contiguous memory
9781: ** representation of the database will usually only exist if there has
9782: ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9783: ** values of D and S.
9784: ** The size of the database is written into *P even if the
9785: ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9786: ** of the database exists.
9787: **
9788: ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9789: ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9790: ** allocation error occurs.
9791: **
9792: ** This interface is only available if SQLite is compiled with the
9793: ** [SQLITE_ENABLE_DESERIALIZE] option.
9794: */
9795: SQLITE_API unsigned char *sqlite3_serialize(
9796: sqlite3 *db, /* The database connection */
9797: const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9798: sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9799: unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9800: );
9801:
9802: /*
9803: ** CAPI3REF: Flags for sqlite3_serialize
9804: **
9805: ** Zero or more of the following constants can be OR-ed together for
9806: ** the F argument to [sqlite3_serialize(D,S,P,F)].
9807: **
9808: ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9809: ** a pointer to contiguous in-memory database that it is currently using,
9810: ** without making a copy of the database. If SQLite is not currently using
9811: ** a contiguous in-memory database, then this option causes
9812: ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9813: ** using a contiguous in-memory database if it has been initialized by a
9814: ** prior call to [sqlite3_deserialize()].
9815: */
9816: #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9817:
9818: /*
9819: ** CAPI3REF: Deserialize a database
9820: **
9821: ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9822: ** [database connection] D to disconnect from database S and then
9823: ** reopen S as an in-memory database based on the serialization contained
9824: ** in P. The serialized database P is N bytes in size. M is the size of
9825: ** the buffer P, which might be larger than N. If M is larger than N, and
9826: ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9827: ** permitted to add content to the in-memory database as long as the total
9828: ** size does not exceed M bytes.
9829: **
9830: ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9831: ** invoke sqlite3_free() on the serialization buffer when the database
9832: ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9833: ** SQLite will try to increase the buffer size using sqlite3_realloc64()
9834: ** if writes on the database cause it to grow larger than M bytes.
9835: **
9836: ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9837: ** database is currently in a read transaction or is involved in a backup
9838: ** operation.
9839: **
9840: ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9841: ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9842: ** [sqlite3_free()] is invoked on argument P prior to returning.
9843: **
9844: ** This interface is only available if SQLite is compiled with the
9845: ** [SQLITE_ENABLE_DESERIALIZE] option.
9846: */
9847: SQLITE_API int sqlite3_deserialize(
9848: sqlite3 *db, /* The database connection */
9849: const char *zSchema, /* Which DB to reopen with the deserialization */
9850: unsigned char *pData, /* The serialized database content */
9851: sqlite3_int64 szDb, /* Number bytes in the deserialization */
9852: sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9853: unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9854: );
9855:
9856: /*
9857: ** CAPI3REF: Flags for sqlite3_deserialize()
9858: **
9859: ** The following are allowed values for 6th argument (the F argument) to
9860: ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9861: **
9862: ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9863: ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9864: ** and that SQLite should take ownership of this memory and automatically
9865: ** free it when it has finished using it. Without this flag, the caller
9866: ** is responsible for freeing any dynamically allocated memory.
9867: **
9868: ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9869: ** grow the size of the database using calls to [sqlite3_realloc64()]. This
9870: ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9871: ** Without this flag, the deserialized database cannot increase in size beyond
9872: ** the number of bytes specified by the M parameter.
9873: **
9874: ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9875: ** should be treated as read-only.
9876: */
9877: #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9878: #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9879: #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9880:
9881: /*
1.2 misho 9882: ** Undo the hack that converts floating point types to integer for
9883: ** builds on processors without floating point support.
9884: */
9885: #ifdef SQLITE_OMIT_FLOATING_POINT
9886: # undef double
9887: #endif
9888:
9889: #ifdef __cplusplus
9890: } /* End of the 'extern "C"' block */
9891: #endif
1.4 misho 9892: #endif /* SQLITE3_H */
1.2 misho 9893:
1.4 misho 9894: /******** Begin file sqlite3rtree.h *********/
1.2 misho 9895: /*
9896: ** 2010 August 30
9897: **
9898: ** The author disclaims copyright to this source code. In place of
9899: ** a legal notice, here is a blessing:
9900: **
9901: ** May you do good and not evil.
9902: ** May you find forgiveness for yourself and forgive others.
9903: ** May you share freely, never taking more than you give.
9904: **
9905: *************************************************************************
9906: */
9907:
9908: #ifndef _SQLITE3RTREE_H_
9909: #define _SQLITE3RTREE_H_
9910:
9911:
9912: #ifdef __cplusplus
9913: extern "C" {
9914: #endif
9915:
9916: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
1.4 misho 9917: typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9918:
9919: /* The double-precision datatype used by RTree depends on the
9920: ** SQLITE_RTREE_INT_ONLY compile-time option.
9921: */
9922: #ifdef SQLITE_RTREE_INT_ONLY
9923: typedef sqlite3_int64 sqlite3_rtree_dbl;
9924: #else
9925: typedef double sqlite3_rtree_dbl;
9926: #endif
1.2 misho 9927:
9928: /*
9929: ** Register a geometry callback named zGeom that can be used as part of an
9930: ** R-Tree geometry query as follows:
9931: **
9932: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9933: */
9934: SQLITE_API int sqlite3_rtree_geometry_callback(
9935: sqlite3 *db,
9936: const char *zGeom,
1.4 misho 9937: int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
1.2 misho 9938: void *pContext
9939: );
9940:
9941:
9942: /*
9943: ** A pointer to a structure of the following type is passed as the first
9944: ** argument to callbacks registered using rtree_geometry_callback().
9945: */
9946: struct sqlite3_rtree_geometry {
9947: void *pContext; /* Copy of pContext passed to s_r_g_c() */
9948: int nParam; /* Size of array aParam[] */
1.4 misho 9949: sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
1.2 misho 9950: void *pUser; /* Callback implementation user data */
9951: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9952: };
9953:
1.4 misho 9954: /*
1.5 misho 9955: ** Register a 2nd-generation geometry callback named zScore that can be
1.4 misho 9956: ** used as part of an R-Tree geometry query as follows:
9957: **
9958: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9959: */
9960: SQLITE_API int sqlite3_rtree_query_callback(
9961: sqlite3 *db,
9962: const char *zQueryFunc,
9963: int (*xQueryFunc)(sqlite3_rtree_query_info*),
9964: void *pContext,
9965: void (*xDestructor)(void*)
9966: );
9967:
9968:
9969: /*
1.5 misho 9970: ** A pointer to a structure of the following type is passed as the
1.4 misho 9971: ** argument to scored geometry callback registered using
9972: ** sqlite3_rtree_query_callback().
9973: **
9974: ** Note that the first 5 fields of this structure are identical to
9975: ** sqlite3_rtree_geometry. This structure is a subclass of
9976: ** sqlite3_rtree_geometry.
9977: */
9978: struct sqlite3_rtree_query_info {
9979: void *pContext; /* pContext from when function registered */
9980: int nParam; /* Number of function parameters */
9981: sqlite3_rtree_dbl *aParam; /* value of function parameters */
9982: void *pUser; /* callback can use this, if desired */
9983: void (*xDelUser)(void*); /* function to free pUser */
9984: sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9985: unsigned int *anQueue; /* Number of pending entries in the queue */
9986: int nCoord; /* Number of coordinates */
9987: int iLevel; /* Level of current node or entry */
9988: int mxLevel; /* The largest iLevel value in the tree */
9989: sqlite3_int64 iRowid; /* Rowid for current entry */
9990: sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9991: int eParentWithin; /* Visibility of parent node */
1.5 misho 9992: int eWithin; /* OUT: Visibility */
1.4 misho 9993: sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9994: /* The following fields are only available in 3.8.11 and later */
9995: sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9996: };
9997:
9998: /*
9999: ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10000: */
10001: #define NOT_WITHIN 0 /* Object completely outside of query region */
10002: #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10003: #define FULLY_WITHIN 2 /* Object fully contained within query region */
10004:
1.2 misho 10005:
10006: #ifdef __cplusplus
10007: } /* end of the 'extern "C"' block */
10008: #endif
10009:
10010: #endif /* ifndef _SQLITE3RTREE_H_ */
10011:
1.4 misho 10012: /******** End of sqlite3rtree.h *********/
10013: /******** Begin file sqlite3session.h *********/
10014:
10015: #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10016: #define __SQLITESESSION_H_ 1
10017:
10018: /*
10019: ** Make sure we can call this stuff from C++.
10020: */
10021: #ifdef __cplusplus
10022: extern "C" {
10023: #endif
10024:
10025:
10026: /*
10027: ** CAPI3REF: Session Object Handle
1.5 misho 10028: **
10029: ** An instance of this object is a [session] that can be used to
10030: ** record changes to a database.
1.4 misho 10031: */
10032: typedef struct sqlite3_session sqlite3_session;
10033:
10034: /*
10035: ** CAPI3REF: Changeset Iterator Handle
1.5 misho 10036: **
10037: ** An instance of this object acts as a cursor for iterating
10038: ** over the elements of a [changeset] or [patchset].
1.4 misho 10039: */
10040: typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10041:
10042: /*
10043: ** CAPI3REF: Create A New Session Object
1.5 misho 10044: ** CONSTRUCTOR: sqlite3_session
1.4 misho 10045: **
10046: ** Create a new session object attached to database handle db. If successful,
10047: ** a pointer to the new object is written to *ppSession and SQLITE_OK is
10048: ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10049: ** error code (e.g. SQLITE_NOMEM) is returned.
10050: **
10051: ** It is possible to create multiple session objects attached to a single
10052: ** database handle.
10053: **
10054: ** Session objects created using this function should be deleted using the
10055: ** [sqlite3session_delete()] function before the database handle that they
10056: ** are attached to is itself closed. If the database handle is closed before
10057: ** the session object is deleted, then the results of calling any session
10058: ** module function, including [sqlite3session_delete()] on the session object
10059: ** are undefined.
10060: **
10061: ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10062: ** is not possible for an application to register a pre-update hook on a
10063: ** database handle that has one or more session objects attached. Nor is
10064: ** it possible to create a session object attached to a database handle for
1.5 misho 10065: ** which a pre-update hook is already defined. The results of attempting
1.4 misho 10066: ** either of these things are undefined.
10067: **
10068: ** The session object will be used to create changesets for tables in
10069: ** database zDb, where zDb is either "main", or "temp", or the name of an
10070: ** attached database. It is not an error if database zDb is not attached
10071: ** to the database when the session object is created.
10072: */
1.5 misho 10073: SQLITE_API int sqlite3session_create(
1.4 misho 10074: sqlite3 *db, /* Database handle */
10075: const char *zDb, /* Name of db (e.g. "main") */
10076: sqlite3_session **ppSession /* OUT: New session object */
10077: );
10078:
10079: /*
10080: ** CAPI3REF: Delete A Session Object
1.5 misho 10081: ** DESTRUCTOR: sqlite3_session
1.4 misho 10082: **
1.5 misho 10083: ** Delete a session object previously allocated using
1.4 misho 10084: ** [sqlite3session_create()]. Once a session object has been deleted, the
10085: ** results of attempting to use pSession with any other session module
10086: ** function are undefined.
10087: **
10088: ** Session objects must be deleted before the database handle to which they
1.5 misho 10089: ** are attached is closed. Refer to the documentation for
1.4 misho 10090: ** [sqlite3session_create()] for details.
10091: */
1.5 misho 10092: SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
1.4 misho 10093:
10094:
10095: /*
10096: ** CAPI3REF: Enable Or Disable A Session Object
1.5 misho 10097: ** METHOD: sqlite3_session
1.4 misho 10098: **
10099: ** Enable or disable the recording of changes by a session object. When
10100: ** enabled, a session object records changes made to the database. When
10101: ** disabled - it does not. A newly created session object is enabled.
10102: ** Refer to the documentation for [sqlite3session_changeset()] for further
10103: ** details regarding how enabling and disabling a session object affects
10104: ** the eventual changesets.
10105: **
10106: ** Passing zero to this function disables the session. Passing a value
1.5 misho 10107: ** greater than zero enables it. Passing a value less than zero is a
1.4 misho 10108: ** no-op, and may be used to query the current state of the session.
10109: **
1.5 misho 10110: ** The return value indicates the final state of the session object: 0 if
1.4 misho 10111: ** the session is disabled, or 1 if it is enabled.
10112: */
1.5 misho 10113: SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
1.4 misho 10114:
10115: /*
10116: ** CAPI3REF: Set Or Clear the Indirect Change Flag
1.5 misho 10117: ** METHOD: sqlite3_session
1.4 misho 10118: **
10119: ** Each change recorded by a session object is marked as either direct or
10120: ** indirect. A change is marked as indirect if either:
10121: **
10122: ** <ul>
10123: ** <li> The session object "indirect" flag is set when the change is
10124: ** made, or
1.5 misho 10125: ** <li> The change is made by an SQL trigger or foreign key action
1.4 misho 10126: ** instead of directly as a result of a users SQL statement.
10127: ** </ul>
10128: **
10129: ** If a single row is affected by more than one operation within a session,
10130: ** then the change is considered indirect if all operations meet the criteria
10131: ** for an indirect change above, or direct otherwise.
10132: **
10133: ** This function is used to set, clear or query the session object indirect
10134: ** flag. If the second argument passed to this function is zero, then the
10135: ** indirect flag is cleared. If it is greater than zero, the indirect flag
10136: ** is set. Passing a value less than zero does not modify the current value
1.5 misho 10137: ** of the indirect flag, and may be used to query the current state of the
1.4 misho 10138: ** indirect flag for the specified session object.
10139: **
1.5 misho 10140: ** The return value indicates the final state of the indirect flag: 0 if
1.4 misho 10141: ** it is clear, or 1 if it is set.
10142: */
1.5 misho 10143: SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
1.4 misho 10144:
10145: /*
10146: ** CAPI3REF: Attach A Table To A Session Object
1.5 misho 10147: ** METHOD: sqlite3_session
1.4 misho 10148: **
10149: ** If argument zTab is not NULL, then it is the name of a table to attach
1.5 misho 10150: ** to the session object passed as the first argument. All subsequent changes
10151: ** made to the table while the session object is enabled will be recorded. See
1.4 misho 10152: ** documentation for [sqlite3session_changeset()] for further details.
10153: **
10154: ** Or, if argument zTab is NULL, then changes are recorded for all tables
1.5 misho 10155: ** in the database. If additional tables are added to the database (by
10156: ** executing "CREATE TABLE" statements) after this call is made, changes for
1.4 misho 10157: ** the new tables are also recorded.
10158: **
10159: ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
1.5 misho 10160: ** defined as part of their CREATE TABLE statement. It does not matter if the
1.4 misho 10161: ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10162: ** KEY may consist of a single column, or may be a composite key.
1.5 misho 10163: **
1.4 misho 10164: ** It is not an error if the named table does not exist in the database. Nor
10165: ** is it an error if the named table does not have a PRIMARY KEY. However,
10166: ** no changes will be recorded in either of these scenarios.
10167: **
10168: ** Changes are not recorded for individual rows that have NULL values stored
10169: ** in one or more of their PRIMARY KEY columns.
10170: **
1.5 misho 10171: ** SQLITE_OK is returned if the call completes without error. Or, if an error
1.4 misho 10172: ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
1.5 misho 10173: **
10174: ** <h3>Special sqlite_stat1 Handling</h3>
10175: **
10176: ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10177: ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10178: ** <pre>
10179: ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
10180: ** </pre>
10181: **
10182: ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10183: ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10184: ** are recorded for rows for which (idx IS NULL) is true. However, for such
10185: ** rows a zero-length blob (SQL value X'') is stored in the changeset or
10186: ** patchset instead of a NULL value. This allows such changesets to be
10187: ** manipulated by legacy implementations of sqlite3changeset_invert(),
10188: ** concat() and similar.
10189: **
10190: ** The sqlite3changeset_apply() function automatically converts the
10191: ** zero-length blob back to a NULL value when updating the sqlite_stat1
10192: ** table. However, if the application calls sqlite3changeset_new(),
10193: ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10194: ** iterator directly (including on a changeset iterator passed to a
10195: ** conflict-handler callback) then the X'' value is returned. The application
10196: ** must translate X'' to NULL itself if required.
10197: **
10198: ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10199: ** changes made to the sqlite_stat1 table. Legacy versions of the
10200: ** sqlite3changeset_apply() function silently ignore any modifications to the
10201: ** sqlite_stat1 table that are part of a changeset or patchset.
1.4 misho 10202: */
1.5 misho 10203: SQLITE_API int sqlite3session_attach(
1.4 misho 10204: sqlite3_session *pSession, /* Session object */
10205: const char *zTab /* Table name */
10206: );
10207:
10208: /*
10209: ** CAPI3REF: Set a table filter on a Session Object.
1.5 misho 10210: ** METHOD: sqlite3_session
1.4 misho 10211: **
1.5 misho 10212: ** The second argument (xFilter) is the "filter callback". For changes to rows
10213: ** in tables that are not attached to the Session object, the filter is called
10214: ** to determine whether changes to the table's rows should be tracked or not.
10215: ** If xFilter returns 0, changes are not tracked. Note that once a table is
1.4 misho 10216: ** attached, xFilter will not be called again.
10217: */
1.5 misho 10218: SQLITE_API void sqlite3session_table_filter(
1.4 misho 10219: sqlite3_session *pSession, /* Session object */
10220: int(*xFilter)(
10221: void *pCtx, /* Copy of third arg to _filter_table() */
10222: const char *zTab /* Table name */
10223: ),
10224: void *pCtx /* First argument passed to xFilter */
10225: );
10226:
10227: /*
10228: ** CAPI3REF: Generate A Changeset From A Session Object
1.5 misho 10229: ** METHOD: sqlite3_session
1.4 misho 10230: **
1.5 misho 10231: ** Obtain a changeset containing changes to the tables attached to the
10232: ** session object passed as the first argument. If successful,
10233: ** set *ppChangeset to point to a buffer containing the changeset
1.4 misho 10234: ** and *pnChangeset to the size of the changeset in bytes before returning
10235: ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10236: ** zero and return an SQLite error code.
10237: **
10238: ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10239: ** each representing a change to a single row of an attached table. An INSERT
10240: ** change contains the values of each field of a new database row. A DELETE
10241: ** contains the original values of each field of a deleted database row. An
10242: ** UPDATE change contains the original values of each field of an updated
10243: ** database row along with the updated values for each updated non-primary-key
10244: ** column. It is not possible for an UPDATE change to represent a change that
10245: ** modifies the values of primary key columns. If such a change is made, it
10246: ** is represented in a changeset as a DELETE followed by an INSERT.
10247: **
1.5 misho 10248: ** Changes are not recorded for rows that have NULL values stored in one or
1.4 misho 10249: ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10250: ** no corresponding change is present in the changesets returned by this
10251: ** function. If an existing row with one or more NULL values stored in
10252: ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10253: ** only an INSERT is appears in the changeset. Similarly, if an existing row
10254: ** with non-NULL PRIMARY KEY values is updated so that one or more of its
10255: ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10256: ** DELETE change only.
10257: **
10258: ** The contents of a changeset may be traversed using an iterator created
10259: ** using the [sqlite3changeset_start()] API. A changeset may be applied to
10260: ** a database with a compatible schema using the [sqlite3changeset_apply()]
10261: ** API.
10262: **
10263: ** Within a changeset generated by this function, all changes related to a
10264: ** single table are grouped together. In other words, when iterating through
10265: ** a changeset or when applying a changeset to a database, all changes related
10266: ** to a single table are processed before moving on to the next table. Tables
10267: ** are sorted in the same order in which they were attached (or auto-attached)
10268: ** to the sqlite3_session object. The order in which the changes related to
10269: ** a single table are stored is undefined.
10270: **
10271: ** Following a successful call to this function, it is the responsibility of
10272: ** the caller to eventually free the buffer that *ppChangeset points to using
10273: ** [sqlite3_free()].
10274: **
10275: ** <h3>Changeset Generation</h3>
10276: **
10277: ** Once a table has been attached to a session object, the session object
10278: ** records the primary key values of all new rows inserted into the table.
10279: ** It also records the original primary key and other column values of any
10280: ** deleted or updated rows. For each unique primary key value, data is only
10281: ** recorded once - the first time a row with said primary key is inserted,
10282: ** updated or deleted in the lifetime of the session.
10283: **
10284: ** There is one exception to the previous paragraph: when a row is inserted,
10285: ** updated or deleted, if one or more of its primary key columns contain a
10286: ** NULL value, no record of the change is made.
10287: **
10288: ** The session object therefore accumulates two types of records - those
10289: ** that consist of primary key values only (created when the user inserts
10290: ** a new record) and those that consist of the primary key values and the
10291: ** original values of other table columns (created when the users deletes
10292: ** or updates a record).
10293: **
10294: ** When this function is called, the requested changeset is created using
10295: ** both the accumulated records and the current contents of the database
10296: ** file. Specifically:
10297: **
10298: ** <ul>
10299: ** <li> For each record generated by an insert, the database is queried
10300: ** for a row with a matching primary key. If one is found, an INSERT
1.5 misho 10301: ** change is added to the changeset. If no such row is found, no change
1.4 misho 10302: ** is added to the changeset.
10303: **
1.5 misho 10304: ** <li> For each record generated by an update or delete, the database is
1.4 misho 10305: ** queried for a row with a matching primary key. If such a row is
10306: ** found and one or more of the non-primary key fields have been
1.5 misho 10307: ** modified from their original values, an UPDATE change is added to
10308: ** the changeset. Or, if no such row is found in the table, a DELETE
1.4 misho 10309: ** change is added to the changeset. If there is a row with a matching
10310: ** primary key in the database, but all fields contain their original
10311: ** values, no change is added to the changeset.
10312: ** </ul>
10313: **
10314: ** This means, amongst other things, that if a row is inserted and then later
10315: ** deleted while a session object is active, neither the insert nor the delete
1.5 misho 10316: ** will be present in the changeset. Or if a row is deleted and then later a
1.4 misho 10317: ** row with the same primary key values inserted while a session object is
10318: ** active, the resulting changeset will contain an UPDATE change instead of
10319: ** a DELETE and an INSERT.
10320: **
10321: ** When a session object is disabled (see the [sqlite3session_enable()] API),
10322: ** it does not accumulate records when rows are inserted, updated or deleted.
10323: ** This may appear to have some counter-intuitive effects if a single row
10324: ** is written to more than once during a session. For example, if a row
1.5 misho 10325: ** is inserted while a session object is enabled, then later deleted while
1.4 misho 10326: ** the same session object is disabled, no INSERT record will appear in the
10327: ** changeset, even though the delete took place while the session was disabled.
1.5 misho 10328: ** Or, if one field of a row is updated while a session is disabled, and
1.4 misho 10329: ** another field of the same row is updated while the session is enabled, the
10330: ** resulting changeset will contain an UPDATE change that updates both fields.
10331: */
1.5 misho 10332: SQLITE_API int sqlite3session_changeset(
1.4 misho 10333: sqlite3_session *pSession, /* Session object */
10334: int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10335: void **ppChangeset /* OUT: Buffer containing changeset */
10336: );
10337:
10338: /*
1.5 misho 10339: ** CAPI3REF: Load The Difference Between Tables Into A Session
10340: ** METHOD: sqlite3_session
1.4 misho 10341: **
10342: ** If it is not already attached to the session object passed as the first
10343: ** argument, this function attaches table zTbl in the same manner as the
10344: ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10345: ** does not have a primary key, this function is a no-op (but does not return
10346: ** an error).
10347: **
10348: ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
1.5 misho 10349: ** attached to the same database handle as the session object that contains
1.4 misho 10350: ** a table compatible with the table attached to the session by this function.
10351: ** A table is considered compatible if it:
10352: **
10353: ** <ul>
10354: ** <li> Has the same name,
10355: ** <li> Has the same set of columns declared in the same order, and
10356: ** <li> Has the same PRIMARY KEY definition.
10357: ** </ul>
10358: **
10359: ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10360: ** are compatible but do not have any PRIMARY KEY columns, it is not an error
10361: ** but no changes are added to the session object. As with other session
10362: ** APIs, tables without PRIMARY KEYs are simply ignored.
10363: **
10364: ** This function adds a set of changes to the session object that could be
1.5 misho 10365: ** used to update the table in database zFrom (call this the "from-table")
10366: ** so that its content is the same as the table attached to the session
1.4 misho 10367: ** object (call this the "to-table"). Specifically:
10368: **
10369: ** <ul>
1.5 misho 10370: ** <li> For each row (primary key) that exists in the to-table but not in
1.4 misho 10371: ** the from-table, an INSERT record is added to the session object.
10372: **
1.5 misho 10373: ** <li> For each row (primary key) that exists in the to-table but not in
1.4 misho 10374: ** the from-table, a DELETE record is added to the session object.
10375: **
1.5 misho 10376: ** <li> For each row (primary key) that exists in both tables, but features
10377: ** different non-PK values in each, an UPDATE record is added to the
10378: ** session.
1.4 misho 10379: ** </ul>
10380: **
10381: ** To clarify, if this function is called and then a changeset constructed
1.5 misho 10382: ** using [sqlite3session_changeset()], then after applying that changeset to
10383: ** database zFrom the contents of the two compatible tables would be
1.4 misho 10384: ** identical.
10385: **
10386: ** It an error if database zFrom does not exist or does not contain the
10387: ** required compatible table.
10388: **
1.5 misho 10389: ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
1.4 misho 10390: ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
1.5 misho 10391: ** may be set to point to a buffer containing an English language error
1.4 misho 10392: ** message. It is the responsibility of the caller to free this buffer using
10393: ** sqlite3_free().
10394: */
1.5 misho 10395: SQLITE_API int sqlite3session_diff(
1.4 misho 10396: sqlite3_session *pSession,
10397: const char *zFromDb,
10398: const char *zTbl,
10399: char **pzErrMsg
10400: );
10401:
10402:
10403: /*
10404: ** CAPI3REF: Generate A Patchset From A Session Object
1.5 misho 10405: ** METHOD: sqlite3_session
1.4 misho 10406: **
10407: ** The differences between a patchset and a changeset are that:
10408: **
10409: ** <ul>
1.5 misho 10410: ** <li> DELETE records consist of the primary key fields only. The
1.4 misho 10411: ** original values of other fields are omitted.
1.5 misho 10412: ** <li> The original values of any modified fields are omitted from
1.4 misho 10413: ** UPDATE records.
10414: ** </ul>
10415: **
1.5 misho 10416: ** A patchset blob may be used with up to date versions of all
10417: ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
1.4 misho 10418: ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10419: ** attempting to use a patchset blob with old versions of the
1.5 misho 10420: ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
1.4 misho 10421: **
1.5 misho 10422: ** Because the non-primary key "old.*" fields are omitted, no
1.4 misho 10423: ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10424: ** is passed to the sqlite3changeset_apply() API. Other conflict types work
10425: ** in the same way as for changesets.
10426: **
10427: ** Changes within a patchset are ordered in the same way as for changesets
10428: ** generated by the sqlite3session_changeset() function (i.e. all changes for
10429: ** a single table are grouped together, tables appear in the order in which
10430: ** they were attached to the session object).
10431: */
1.5 misho 10432: SQLITE_API int sqlite3session_patchset(
1.4 misho 10433: sqlite3_session *pSession, /* Session object */
1.5 misho 10434: int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
10435: void **ppPatchset /* OUT: Buffer containing patchset */
1.4 misho 10436: );
10437:
10438: /*
10439: ** CAPI3REF: Test if a changeset has recorded any changes.
10440: **
1.5 misho 10441: ** Return non-zero if no changes to attached tables have been recorded by
10442: ** the session object passed as the first argument. Otherwise, if one or
1.4 misho 10443: ** more changes have been recorded, return zero.
10444: **
10445: ** Even if this function returns zero, it is possible that calling
10446: ** [sqlite3session_changeset()] on the session handle may still return a
1.5 misho 10447: ** changeset that contains no changes. This can happen when a row in
10448: ** an attached table is modified and then later on the original values
1.4 misho 10449: ** are restored. However, if this function returns non-zero, then it is
1.5 misho 10450: ** guaranteed that a call to sqlite3session_changeset() will return a
1.4 misho 10451: ** changeset containing zero changes.
10452: */
1.5 misho 10453: SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
1.4 misho 10454:
10455: /*
1.6 ! misho 10456: ** CAPI3REF: Query for the amount of heap memory used by a session object.
! 10457: **
! 10458: ** This API returns the total amount of heap memory in bytes currently
! 10459: ** used by the session object passed as the only argument.
! 10460: */
! 10461: SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
! 10462:
! 10463: /*
1.5 misho 10464: ** CAPI3REF: Create An Iterator To Traverse A Changeset
10465: ** CONSTRUCTOR: sqlite3_changeset_iter
1.4 misho 10466: **
10467: ** Create an iterator used to iterate through the contents of a changeset.
10468: ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
10469: ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
10470: ** SQLite error code is returned.
10471: **
1.5 misho 10472: ** The following functions can be used to advance and query a changeset
1.4 misho 10473: ** iterator created by this function:
10474: **
10475: ** <ul>
10476: ** <li> [sqlite3changeset_next()]
10477: ** <li> [sqlite3changeset_op()]
10478: ** <li> [sqlite3changeset_new()]
10479: ** <li> [sqlite3changeset_old()]
10480: ** </ul>
10481: **
10482: ** It is the responsibility of the caller to eventually destroy the iterator
10483: ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
10484: ** changeset (pChangeset) must remain valid until after the iterator is
10485: ** destroyed.
10486: **
10487: ** Assuming the changeset blob was created by one of the
10488: ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
1.5 misho 10489: ** [sqlite3changeset_invert()] functions, all changes within the changeset
10490: ** that apply to a single table are grouped together. This means that when
10491: ** an application iterates through a changeset using an iterator created by
10492: ** this function, all changes that relate to a single table are visited
10493: ** consecutively. There is no chance that the iterator will visit a change
10494: ** the applies to table X, then one for table Y, and then later on visit
1.4 misho 10495: ** another change for table X.
1.5 misho 10496: **
10497: ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
10498: ** may be modified by passing a combination of
10499: ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
10500: **
10501: ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
10502: ** and therefore subject to change.
1.4 misho 10503: */
1.5 misho 10504: SQLITE_API int sqlite3changeset_start(
1.4 misho 10505: sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10506: int nChangeset, /* Size of changeset blob in bytes */
10507: void *pChangeset /* Pointer to blob containing changeset */
10508: );
1.5 misho 10509: SQLITE_API int sqlite3changeset_start_v2(
10510: sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10511: int nChangeset, /* Size of changeset blob in bytes */
10512: void *pChangeset, /* Pointer to blob containing changeset */
10513: int flags /* SESSION_CHANGESETSTART_* flags */
10514: );
10515:
10516: /*
10517: ** CAPI3REF: Flags for sqlite3changeset_start_v2
10518: **
10519: ** The following flags may passed via the 4th parameter to
10520: ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10521: **
10522: ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10523: ** Invert the changeset while iterating through it. This is equivalent to
10524: ** inverting a changeset using sqlite3changeset_invert() before applying it.
10525: ** It is an error to specify this flag with a patchset.
10526: */
10527: #define SQLITE_CHANGESETSTART_INVERT 0x0002
1.4 misho 10528:
10529:
10530: /*
10531: ** CAPI3REF: Advance A Changeset Iterator
1.5 misho 10532: ** METHOD: sqlite3_changeset_iter
1.4 misho 10533: **
1.5 misho 10534: ** This function may only be used with iterators created by the function
1.4 misho 10535: ** [sqlite3changeset_start()]. If it is called on an iterator passed to
10536: ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10537: ** is returned and the call has no effect.
10538: **
10539: ** Immediately after an iterator is created by sqlite3changeset_start(), it
10540: ** does not point to any change in the changeset. Assuming the changeset
10541: ** is not empty, the first call to this function advances the iterator to
10542: ** point to the first change in the changeset. Each subsequent call advances
10543: ** the iterator to point to the next change in the changeset (if any). If
10544: ** no error occurs and the iterator points to a valid change after a call
1.5 misho 10545: ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
1.4 misho 10546: ** Otherwise, if all changes in the changeset have already been visited,
10547: ** SQLITE_DONE is returned.
10548: **
1.5 misho 10549: ** If an error occurs, an SQLite error code is returned. Possible error
10550: ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
1.4 misho 10551: ** SQLITE_NOMEM.
10552: */
1.5 misho 10553: SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
1.4 misho 10554:
10555: /*
10556: ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
1.5 misho 10557: ** METHOD: sqlite3_changeset_iter
1.4 misho 10558: **
10559: ** The pIter argument passed to this function may either be an iterator
10560: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10561: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10562: ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10563: ** is not the case, this function returns [SQLITE_MISUSE].
10564: **
1.6 ! misho 10565: ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
! 10566: ** outputs are set through these pointers:
! 10567: **
! 10568: ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
! 10569: ** depending on the type of change that the iterator currently points to;
! 10570: **
! 10571: ** *pnCol is set to the number of columns in the table affected by the change; and
! 10572: **
! 10573: ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
! 10574: ** the name of the table affected by the current change. The buffer remains
! 10575: ** valid until either sqlite3changeset_next() is called on the iterator
! 10576: ** or until the conflict-handler function returns.
! 10577: **
! 10578: ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
1.4 misho 10579: ** is an indirect change, or false (0) otherwise. See the documentation for
10580: ** [sqlite3session_indirect()] for a description of direct and indirect
1.6 ! misho 10581: ** changes.
1.4 misho 10582: **
10583: ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10584: ** SQLite error code is returned. The values of the output variables may not
10585: ** be trusted in this case.
10586: */
1.5 misho 10587: SQLITE_API int sqlite3changeset_op(
1.4 misho 10588: sqlite3_changeset_iter *pIter, /* Iterator object */
10589: const char **pzTab, /* OUT: Pointer to table name */
10590: int *pnCol, /* OUT: Number of columns in table */
10591: int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10592: int *pbIndirect /* OUT: True for an 'indirect' change */
10593: );
10594:
10595: /*
10596: ** CAPI3REF: Obtain The Primary Key Definition Of A Table
1.5 misho 10597: ** METHOD: sqlite3_changeset_iter
1.4 misho 10598: **
10599: ** For each modified table, a changeset includes the following:
10600: **
10601: ** <ul>
10602: ** <li> The number of columns in the table, and
10603: ** <li> Which of those columns make up the tables PRIMARY KEY.
10604: ** </ul>
10605: **
10606: ** This function is used to find which columns comprise the PRIMARY KEY of
10607: ** the table modified by the change that iterator pIter currently points to.
10608: ** If successful, *pabPK is set to point to an array of nCol entries, where
10609: ** nCol is the number of columns in the table. Elements of *pabPK are set to
10610: ** 0x01 if the corresponding column is part of the tables primary key, or
10611: ** 0x00 if it is not.
10612: **
1.5 misho 10613: ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
1.4 misho 10614: ** in the table.
10615: **
10616: ** If this function is called when the iterator does not point to a valid
10617: ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10618: ** SQLITE_OK is returned and the output variables populated as described
10619: ** above.
10620: */
1.5 misho 10621: SQLITE_API int sqlite3changeset_pk(
1.4 misho 10622: sqlite3_changeset_iter *pIter, /* Iterator object */
10623: unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10624: int *pnCol /* OUT: Number of entries in output array */
10625: );
10626:
10627: /*
10628: ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
1.5 misho 10629: ** METHOD: sqlite3_changeset_iter
1.4 misho 10630: **
10631: ** The pIter argument passed to this function may either be an iterator
10632: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10633: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
1.5 misho 10634: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
1.4 misho 10635: ** Furthermore, it may only be called if the type of change that the iterator
10636: ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10637: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10638: **
10639: ** Argument iVal must be greater than or equal to 0, and less than the number
10640: ** of columns in the table affected by the current change. Otherwise,
10641: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10642: **
10643: ** If successful, this function sets *ppValue to point to a protected
1.5 misho 10644: ** sqlite3_value object containing the iVal'th value from the vector of
1.4 misho 10645: ** original row values stored as part of the UPDATE or DELETE change and
1.5 misho 10646: ** returns SQLITE_OK. The name of the function comes from the fact that this
1.4 misho 10647: ** is similar to the "old.*" columns available to update or delete triggers.
10648: **
10649: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10650: ** is returned and *ppValue is set to NULL.
10651: */
1.5 misho 10652: SQLITE_API int sqlite3changeset_old(
1.4 misho 10653: sqlite3_changeset_iter *pIter, /* Changeset iterator */
10654: int iVal, /* Column number */
10655: sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10656: );
10657:
10658: /*
10659: ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
1.5 misho 10660: ** METHOD: sqlite3_changeset_iter
1.4 misho 10661: **
10662: ** The pIter argument passed to this function may either be an iterator
10663: ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10664: ** created by [sqlite3changeset_start()]. In the latter case, the most recent
1.5 misho 10665: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
1.4 misho 10666: ** Furthermore, it may only be called if the type of change that the iterator
10667: ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10668: ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10669: **
10670: ** Argument iVal must be greater than or equal to 0, and less than the number
10671: ** of columns in the table affected by the current change. Otherwise,
10672: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10673: **
10674: ** If successful, this function sets *ppValue to point to a protected
1.5 misho 10675: ** sqlite3_value object containing the iVal'th value from the vector of
1.4 misho 10676: ** new row values stored as part of the UPDATE or INSERT change and
10677: ** returns SQLITE_OK. If the change is an UPDATE and does not include
1.5 misho 10678: ** a new value for the requested column, *ppValue is set to NULL and
10679: ** SQLITE_OK returned. The name of the function comes from the fact that
10680: ** this is similar to the "new.*" columns available to update or delete
1.4 misho 10681: ** triggers.
10682: **
10683: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10684: ** is returned and *ppValue is set to NULL.
10685: */
1.5 misho 10686: SQLITE_API int sqlite3changeset_new(
1.4 misho 10687: sqlite3_changeset_iter *pIter, /* Changeset iterator */
10688: int iVal, /* Column number */
10689: sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10690: );
10691:
10692: /*
10693: ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
1.5 misho 10694: ** METHOD: sqlite3_changeset_iter
1.4 misho 10695: **
10696: ** This function should only be used with iterator objects passed to a
10697: ** conflict-handler callback by [sqlite3changeset_apply()] with either
10698: ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10699: ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10700: ** is set to NULL.
10701: **
10702: ** Argument iVal must be greater than or equal to 0, and less than the number
10703: ** of columns in the table affected by the current change. Otherwise,
10704: ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10705: **
10706: ** If successful, this function sets *ppValue to point to a protected
1.5 misho 10707: ** sqlite3_value object containing the iVal'th value from the
1.4 misho 10708: ** "conflicting row" associated with the current conflict-handler callback
10709: ** and returns SQLITE_OK.
10710: **
10711: ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10712: ** is returned and *ppValue is set to NULL.
10713: */
1.5 misho 10714: SQLITE_API int sqlite3changeset_conflict(
1.4 misho 10715: sqlite3_changeset_iter *pIter, /* Changeset iterator */
10716: int iVal, /* Column number */
10717: sqlite3_value **ppValue /* OUT: Value from conflicting row */
10718: );
10719:
10720: /*
10721: ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
1.5 misho 10722: ** METHOD: sqlite3_changeset_iter
1.4 misho 10723: **
10724: ** This function may only be called with an iterator passed to an
10725: ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10726: ** it sets the output variable to the total number of known foreign key
10727: ** violations in the destination database and returns SQLITE_OK.
10728: **
10729: ** In all other cases this function returns SQLITE_MISUSE.
10730: */
1.5 misho 10731: SQLITE_API int sqlite3changeset_fk_conflicts(
1.4 misho 10732: sqlite3_changeset_iter *pIter, /* Changeset iterator */
10733: int *pnOut /* OUT: Number of FK violations */
10734: );
10735:
10736:
10737: /*
10738: ** CAPI3REF: Finalize A Changeset Iterator
1.5 misho 10739: ** METHOD: sqlite3_changeset_iter
1.4 misho 10740: **
10741: ** This function is used to finalize an iterator allocated with
10742: ** [sqlite3changeset_start()].
10743: **
10744: ** This function should only be called on iterators created using the
10745: ** [sqlite3changeset_start()] function. If an application calls this
10746: ** function with an iterator passed to a conflict-handler by
10747: ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10748: ** call has no effect.
10749: **
10750: ** If an error was encountered within a call to an sqlite3changeset_xxx()
1.5 misho 10751: ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
1.4 misho 10752: ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10753: ** to that error is returned by this function. Otherwise, SQLITE_OK is
10754: ** returned. This is to allow the following pattern (pseudo-code):
10755: **
1.5 misho 10756: ** <pre>
1.4 misho 10757: ** sqlite3changeset_start();
10758: ** while( SQLITE_ROW==sqlite3changeset_next() ){
10759: ** // Do something with change.
10760: ** }
10761: ** rc = sqlite3changeset_finalize();
10762: ** if( rc!=SQLITE_OK ){
1.5 misho 10763: ** // An error has occurred
1.4 misho 10764: ** }
1.5 misho 10765: ** </pre>
1.4 misho 10766: */
1.5 misho 10767: SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
1.4 misho 10768:
10769: /*
10770: ** CAPI3REF: Invert A Changeset
10771: **
10772: ** This function is used to "invert" a changeset object. Applying an inverted
10773: ** changeset to a database reverses the effects of applying the uninverted
10774: ** changeset. Specifically:
10775: **
10776: ** <ul>
10777: ** <li> Each DELETE change is changed to an INSERT, and
10778: ** <li> Each INSERT change is changed to a DELETE, and
10779: ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10780: ** </ul>
10781: **
10782: ** This function does not change the order in which changes appear within
10783: ** the changeset. It merely reverses the sense of each individual change.
10784: **
10785: ** If successful, a pointer to a buffer containing the inverted changeset
10786: ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10787: ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10788: ** zeroed and an SQLite error code returned.
10789: **
10790: ** It is the responsibility of the caller to eventually call sqlite3_free()
1.5 misho 10791: ** on the *ppOut pointer to free the buffer allocation following a successful
1.4 misho 10792: ** call to this function.
10793: **
10794: ** WARNING/TODO: This function currently assumes that the input is a valid
10795: ** changeset. If it is not, the results are undefined.
10796: */
1.5 misho 10797: SQLITE_API int sqlite3changeset_invert(
1.4 misho 10798: int nIn, const void *pIn, /* Input changeset */
10799: int *pnOut, void **ppOut /* OUT: Inverse of input */
10800: );
10801:
10802: /*
10803: ** CAPI3REF: Concatenate Two Changeset Objects
10804: **
1.5 misho 10805: ** This function is used to concatenate two changesets, A and B, into a
1.4 misho 10806: ** single changeset. The result is a changeset equivalent to applying
1.5 misho 10807: ** changeset A followed by changeset B.
1.4 misho 10808: **
1.5 misho 10809: ** This function combines the two input changesets using an
1.4 misho 10810: ** sqlite3_changegroup object. Calling it produces similar results as the
10811: ** following code fragment:
10812: **
1.5 misho 10813: ** <pre>
1.4 misho 10814: ** sqlite3_changegroup *pGrp;
10815: ** rc = sqlite3_changegroup_new(&pGrp);
10816: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10817: ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10818: ** if( rc==SQLITE_OK ){
10819: ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10820: ** }else{
10821: ** *ppOut = 0;
10822: ** *pnOut = 0;
10823: ** }
1.5 misho 10824: ** </pre>
1.4 misho 10825: **
10826: ** Refer to the sqlite3_changegroup documentation below for details.
10827: */
1.5 misho 10828: SQLITE_API int sqlite3changeset_concat(
1.4 misho 10829: int nA, /* Number of bytes in buffer pA */
10830: void *pA, /* Pointer to buffer containing changeset A */
10831: int nB, /* Number of bytes in buffer pB */
10832: void *pB, /* Pointer to buffer containing changeset B */
10833: int *pnOut, /* OUT: Number of bytes in output changeset */
10834: void **ppOut /* OUT: Buffer containing output changeset */
10835: );
10836:
10837:
10838: /*
1.5 misho 10839: ** CAPI3REF: Changegroup Handle
10840: **
10841: ** A changegroup is an object used to combine two or more
10842: ** [changesets] or [patchsets]
1.4 misho 10843: */
10844: typedef struct sqlite3_changegroup sqlite3_changegroup;
10845:
10846: /*
1.5 misho 10847: ** CAPI3REF: Create A New Changegroup Object
10848: ** CONSTRUCTOR: sqlite3_changegroup
1.4 misho 10849: **
10850: ** An sqlite3_changegroup object is used to combine two or more changesets
10851: ** (or patchsets) into a single changeset (or patchset). A single changegroup
10852: ** object may combine changesets or patchsets, but not both. The output is
10853: ** always in the same format as the input.
10854: **
10855: ** If successful, this function returns SQLITE_OK and populates (*pp) with
10856: ** a pointer to a new sqlite3_changegroup object before returning. The caller
1.5 misho 10857: ** should eventually free the returned object using a call to
1.4 misho 10858: ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10859: ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10860: **
10861: ** The usual usage pattern for an sqlite3_changegroup object is as follows:
10862: **
10863: ** <ul>
10864: ** <li> It is created using a call to sqlite3changegroup_new().
10865: **
10866: ** <li> Zero or more changesets (or patchsets) are added to the object
10867: ** by calling sqlite3changegroup_add().
10868: **
1.5 misho 10869: ** <li> The result of combining all input changesets together is obtained
1.4 misho 10870: ** by the application via a call to sqlite3changegroup_output().
10871: **
10872: ** <li> The object is deleted using a call to sqlite3changegroup_delete().
10873: ** </ul>
10874: **
10875: ** Any number of calls to add() and output() may be made between the calls to
10876: ** new() and delete(), and in any order.
10877: **
1.5 misho 10878: ** As well as the regular sqlite3changegroup_add() and
1.4 misho 10879: ** sqlite3changegroup_output() functions, also available are the streaming
10880: ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10881: */
1.5 misho 10882: SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
1.4 misho 10883:
10884: /*
1.5 misho 10885: ** CAPI3REF: Add A Changeset To A Changegroup
10886: ** METHOD: sqlite3_changegroup
10887: **
1.4 misho 10888: ** Add all changes within the changeset (or patchset) in buffer pData (size
1.5 misho 10889: ** nData bytes) to the changegroup.
1.4 misho 10890: **
10891: ** If the buffer contains a patchset, then all prior calls to this function
10892: ** on the same changegroup object must also have specified patchsets. Or, if
10893: ** the buffer contains a changeset, so must have the earlier calls to this
10894: ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10895: ** to the changegroup.
10896: **
10897: ** Rows within the changeset and changegroup are identified by the values in
10898: ** their PRIMARY KEY columns. A change in the changeset is considered to
10899: ** apply to the same row as a change already present in the changegroup if
10900: ** the two rows have the same primary key.
10901: **
1.5 misho 10902: ** Changes to rows that do not already appear in the changegroup are
1.4 misho 10903: ** simply copied into it. Or, if both the new changeset and the changegroup
10904: ** contain changes that apply to a single row, the final contents of the
10905: ** changegroup depends on the type of each change, as follows:
10906: **
10907: ** <table border=1 style="margin-left:8ex;margin-right:8ex">
10908: ** <tr><th style="white-space:pre">Existing Change </th>
10909: ** <th style="white-space:pre">New Change </th>
10910: ** <th>Output Change
10911: ** <tr><td>INSERT <td>INSERT <td>
10912: ** The new change is ignored. This case does not occur if the new
10913: ** changeset was recorded immediately after the changesets already
10914: ** added to the changegroup.
10915: ** <tr><td>INSERT <td>UPDATE <td>
1.5 misho 10916: ** The INSERT change remains in the changegroup. The values in the
1.4 misho 10917: ** INSERT change are modified as if the row was inserted by the
10918: ** existing change and then updated according to the new change.
10919: ** <tr><td>INSERT <td>DELETE <td>
10920: ** The existing INSERT is removed from the changegroup. The DELETE is
10921: ** not added.
10922: ** <tr><td>UPDATE <td>INSERT <td>
10923: ** The new change is ignored. This case does not occur if the new
10924: ** changeset was recorded immediately after the changesets already
10925: ** added to the changegroup.
10926: ** <tr><td>UPDATE <td>UPDATE <td>
1.5 misho 10927: ** The existing UPDATE remains within the changegroup. It is amended
10928: ** so that the accompanying values are as if the row was updated once
1.4 misho 10929: ** by the existing change and then again by the new change.
10930: ** <tr><td>UPDATE <td>DELETE <td>
10931: ** The existing UPDATE is replaced by the new DELETE within the
10932: ** changegroup.
10933: ** <tr><td>DELETE <td>INSERT <td>
10934: ** If one or more of the column values in the row inserted by the
1.5 misho 10935: ** new change differ from those in the row deleted by the existing
1.4 misho 10936: ** change, the existing DELETE is replaced by an UPDATE within the
1.5 misho 10937: ** changegroup. Otherwise, if the inserted row is exactly the same
1.4 misho 10938: ** as the deleted row, the existing DELETE is simply discarded.
10939: ** <tr><td>DELETE <td>UPDATE <td>
10940: ** The new change is ignored. This case does not occur if the new
10941: ** changeset was recorded immediately after the changesets already
10942: ** added to the changegroup.
10943: ** <tr><td>DELETE <td>DELETE <td>
10944: ** The new change is ignored. This case does not occur if the new
10945: ** changeset was recorded immediately after the changesets already
10946: ** added to the changegroup.
10947: ** </table>
10948: **
10949: ** If the new changeset contains changes to a table that is already present
10950: ** in the changegroup, then the number of columns and the position of the
10951: ** primary key columns for the table must be consistent. If this is not the
10952: ** case, this function fails with SQLITE_SCHEMA. If the input changeset
10953: ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10954: ** returned. Or, if an out-of-memory condition occurs during processing, this
1.5 misho 10955: ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
10956: ** of the final contents of the changegroup is undefined.
1.4 misho 10957: **
10958: ** If no error occurs, SQLITE_OK is returned.
10959: */
1.5 misho 10960: SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
1.4 misho 10961:
10962: /*
1.5 misho 10963: ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10964: ** METHOD: sqlite3_changegroup
10965: **
1.4 misho 10966: ** Obtain a buffer containing a changeset (or patchset) representing the
10967: ** current contents of the changegroup. If the inputs to the changegroup
10968: ** were themselves changesets, the output is a changeset. Or, if the
10969: ** inputs were patchsets, the output is also a patchset.
10970: **
10971: ** As with the output of the sqlite3session_changeset() and
10972: ** sqlite3session_patchset() functions, all changes related to a single
10973: ** table are grouped together in the output of this function. Tables appear
10974: ** in the same order as for the very first changeset added to the changegroup.
10975: ** If the second or subsequent changesets added to the changegroup contain
10976: ** changes for tables that do not appear in the first changeset, they are
10977: ** appended onto the end of the output changeset, again in the order in
10978: ** which they are first encountered.
10979: **
10980: ** If an error occurs, an SQLite error code is returned and the output
10981: ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
1.5 misho 10982: ** is returned and the output variables are set to the size of and a
1.4 misho 10983: ** pointer to the output buffer, respectively. In this case it is the
10984: ** responsibility of the caller to eventually free the buffer using a
10985: ** call to sqlite3_free().
10986: */
1.5 misho 10987: SQLITE_API int sqlite3changegroup_output(
1.4 misho 10988: sqlite3_changegroup*,
10989: int *pnData, /* OUT: Size of output buffer in bytes */
10990: void **ppData /* OUT: Pointer to output buffer */
10991: );
10992:
10993: /*
1.5 misho 10994: ** CAPI3REF: Delete A Changegroup Object
10995: ** DESTRUCTOR: sqlite3_changegroup
1.4 misho 10996: */
1.5 misho 10997: SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
1.4 misho 10998:
10999: /*
11000: ** CAPI3REF: Apply A Changeset To A Database
11001: **
1.5 misho 11002: ** Apply a changeset or patchset to a database. These functions attempt to
11003: ** update the "main" database attached to handle db with the changes found in
11004: ** the changeset passed via the second and third arguments.
1.4 misho 11005: **
1.5 misho 11006: ** The fourth argument (xFilter) passed to these functions is the "filter
1.4 misho 11007: ** callback". If it is not NULL, then for each table affected by at least one
11008: ** change in the changeset, the filter callback is invoked with
11009: ** the table name as the second argument, and a copy of the context pointer
1.5 misho 11010: ** passed as the sixth argument as the first. If the "filter callback"
11011: ** returns zero, then no attempt is made to apply any changes to the table.
11012: ** Otherwise, if the return value is non-zero or the xFilter argument to
11013: ** is NULL, all changes related to the table are attempted.
1.4 misho 11014: **
1.5 misho 11015: ** For each table that is not excluded by the filter callback, this function
11016: ** tests that the target database contains a compatible table. A table is
1.4 misho 11017: ** considered compatible if all of the following are true:
11018: **
11019: ** <ul>
1.5 misho 11020: ** <li> The table has the same name as the name recorded in the
1.4 misho 11021: ** changeset, and
1.5 misho 11022: ** <li> The table has at least as many columns as recorded in the
1.4 misho 11023: ** changeset, and
1.5 misho 11024: ** <li> The table has primary key columns in the same position as
1.4 misho 11025: ** recorded in the changeset.
11026: ** </ul>
11027: **
11028: ** If there is no compatible table, it is not an error, but none of the
11029: ** changes associated with the table are applied. A warning message is issued
11030: ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11031: ** one such warning is issued for each table in the changeset.
11032: **
1.5 misho 11033: ** For each change for which there is a compatible table, an attempt is made
11034: ** to modify the table contents according to the UPDATE, INSERT or DELETE
11035: ** change. If a change cannot be applied cleanly, the conflict handler
11036: ** function passed as the fifth argument to sqlite3changeset_apply() may be
11037: ** invoked. A description of exactly when the conflict handler is invoked for
1.4 misho 11038: ** each type of change is below.
11039: **
11040: ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11041: ** of passing anything other than a valid function pointer as the xConflict
11042: ** argument are undefined.
11043: **
11044: ** Each time the conflict handler function is invoked, it must return one
1.5 misho 11045: ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
1.4 misho 11046: ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11047: ** if the second argument passed to the conflict handler is either
11048: ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11049: ** returns an illegal value, any changes already made are rolled back and
1.5 misho 11050: ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
1.4 misho 11051: ** actions are taken by sqlite3changeset_apply() depending on the value
11052: ** returned by each invocation of the conflict-handler function. Refer to
1.5 misho 11053: ** the documentation for the three
1.4 misho 11054: ** [SQLITE_CHANGESET_OMIT|available return values] for details.
11055: **
11056: ** <dl>
11057: ** <dt>DELETE Changes<dd>
1.5 misho 11058: ** For each DELETE change, the function checks if the target database
11059: ** contains a row with the same primary key value (or values) as the
11060: ** original row values stored in the changeset. If it does, and the values
11061: ** stored in all non-primary key columns also match the values stored in
1.4 misho 11062: ** the changeset the row is deleted from the target database.
11063: **
11064: ** If a row with matching primary key values is found, but one or more of
11065: ** the non-primary key fields contains a value different from the original
11066: ** row value stored in the changeset, the conflict-handler function is
1.5 misho 11067: ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11068: ** database table has more columns than are recorded in the changeset,
11069: ** only the values of those non-primary key fields are compared against
11070: ** the current database contents - any trailing database table columns
11071: ** are ignored.
1.4 misho 11072: **
11073: ** If no row with matching primary key values is found in the database,
11074: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11075: ** passed as the second argument.
11076: **
11077: ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11078: ** (which can only happen if a foreign key constraint is violated), the
11079: ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11080: ** passed as the second argument. This includes the case where the DELETE
11081: ** operation is attempted because an earlier call to the conflict handler
11082: ** function returned [SQLITE_CHANGESET_REPLACE].
11083: **
11084: ** <dt>INSERT Changes<dd>
11085: ** For each INSERT change, an attempt is made to insert the new row into
1.5 misho 11086: ** the database. If the changeset row contains fewer fields than the
11087: ** database table, the trailing fields are populated with their default
11088: ** values.
1.4 misho 11089: **
1.5 misho 11090: ** If the attempt to insert the row fails because the database already
1.4 misho 11091: ** contains a row with the same primary key values, the conflict handler
1.5 misho 11092: ** function is invoked with the second argument set to
1.4 misho 11093: ** [SQLITE_CHANGESET_CONFLICT].
11094: **
11095: ** If the attempt to insert the row fails because of some other constraint
1.5 misho 11096: ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
1.4 misho 11097: ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
1.5 misho 11098: ** This includes the case where the INSERT operation is re-attempted because
11099: ** an earlier call to the conflict handler function returned
1.4 misho 11100: ** [SQLITE_CHANGESET_REPLACE].
11101: **
11102: ** <dt>UPDATE Changes<dd>
1.5 misho 11103: ** For each UPDATE change, the function checks if the target database
11104: ** contains a row with the same primary key value (or values) as the
11105: ** original row values stored in the changeset. If it does, and the values
11106: ** stored in all modified non-primary key columns also match the values
11107: ** stored in the changeset the row is updated within the target database.
1.4 misho 11108: **
11109: ** If a row with matching primary key values is found, but one or more of
1.5 misho 11110: ** the modified non-primary key fields contains a value different from an
11111: ** original row value stored in the changeset, the conflict-handler function
11112: ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
1.4 misho 11113: ** UPDATE changes only contain values for non-primary key fields that are
11114: ** to be modified, only those fields need to match the original values to
11115: ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11116: **
11117: ** If no row with matching primary key values is found in the database,
11118: ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11119: ** passed as the second argument.
11120: **
1.5 misho 11121: ** If the UPDATE operation is attempted, but SQLite returns
11122: ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
1.4 misho 11123: ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
1.5 misho 11124: ** This includes the case where the UPDATE operation is attempted after
1.4 misho 11125: ** an earlier call to the conflict handler function returned
1.5 misho 11126: ** [SQLITE_CHANGESET_REPLACE].
1.4 misho 11127: ** </dl>
11128: **
11129: ** It is safe to execute SQL statements, including those that write to the
11130: ** table that the callback related to, from within the xConflict callback.
1.5 misho 11131: ** This can be used to further customize the application's conflict
1.4 misho 11132: ** resolution strategy.
11133: **
1.5 misho 11134: ** All changes made by these functions are enclosed in a savepoint transaction.
1.4 misho 11135: ** If any other error (aside from a constraint failure when attempting to
11136: ** write to the target database) occurs, then the savepoint transaction is
1.5 misho 11137: ** rolled back, restoring the target database to its original state, and an
1.4 misho 11138: ** SQLite error code returned.
1.5 misho 11139: **
11140: ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11141: ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11142: ** may set (*ppRebase) to point to a "rebase" that may be used with the
11143: ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11144: ** is set to the size of the buffer in bytes. It is the responsibility of the
11145: ** caller to eventually free any such buffer using sqlite3_free(). The buffer
11146: ** is only allocated and populated if one or more conflicts were encountered
11147: ** while applying the patchset. See comments surrounding the sqlite3_rebaser
11148: ** APIs for further details.
11149: **
11150: ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11151: ** may be modified by passing a combination of
11152: ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11153: **
11154: ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11155: ** and therefore subject to change.
1.4 misho 11156: */
1.5 misho 11157: SQLITE_API int sqlite3changeset_apply(
1.4 misho 11158: sqlite3 *db, /* Apply change to "main" db of this handle */
11159: int nChangeset, /* Size of changeset in bytes */
11160: void *pChangeset, /* Changeset blob */
11161: int(*xFilter)(
11162: void *pCtx, /* Copy of sixth arg to _apply() */
11163: const char *zTab /* Table name */
11164: ),
11165: int(*xConflict)(
11166: void *pCtx, /* Copy of sixth arg to _apply() */
11167: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11168: sqlite3_changeset_iter *p /* Handle describing change and conflict */
11169: ),
11170: void *pCtx /* First argument passed to xConflict */
11171: );
1.5 misho 11172: SQLITE_API int sqlite3changeset_apply_v2(
11173: sqlite3 *db, /* Apply change to "main" db of this handle */
11174: int nChangeset, /* Size of changeset in bytes */
11175: void *pChangeset, /* Changeset blob */
11176: int(*xFilter)(
11177: void *pCtx, /* Copy of sixth arg to _apply() */
11178: const char *zTab /* Table name */
11179: ),
11180: int(*xConflict)(
11181: void *pCtx, /* Copy of sixth arg to _apply() */
11182: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11183: sqlite3_changeset_iter *p /* Handle describing change and conflict */
11184: ),
11185: void *pCtx, /* First argument passed to xConflict */
11186: void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11187: int flags /* SESSION_CHANGESETAPPLY_* flags */
11188: );
1.4 misho 11189:
1.5 misho 11190: /*
11191: ** CAPI3REF: Flags for sqlite3changeset_apply_v2
11192: **
11193: ** The following flags may passed via the 9th parameter to
11194: ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11195: **
11196: ** <dl>
11197: ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11198: ** Usually, the sessions module encloses all operations performed by
11199: ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11200: ** SAVEPOINT is committed if the changeset or patchset is successfully
11201: ** applied, or rolled back if an error occurs. Specifying this flag
11202: ** causes the sessions module to omit this savepoint. In this case, if the
11203: ** caller has an open transaction or savepoint when apply_v2() is called,
11204: ** it may revert the partially applied changeset by rolling it back.
11205: **
11206: ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11207: ** Invert the changeset before applying it. This is equivalent to inverting
11208: ** a changeset using sqlite3changeset_invert() before applying it. It is
11209: ** an error to specify this flag with a patchset.
11210: */
11211: #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11212: #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11213:
11214: /*
1.4 misho 11215: ** CAPI3REF: Constants Passed To The Conflict Handler
11216: **
11217: ** Values that may be passed as the second argument to a conflict-handler.
11218: **
11219: ** <dl>
11220: ** <dt>SQLITE_CHANGESET_DATA<dd>
11221: ** The conflict handler is invoked with CHANGESET_DATA as the second argument
11222: ** when processing a DELETE or UPDATE change if a row with the required
1.5 misho 11223: ** PRIMARY KEY fields is present in the database, but one or more other
11224: ** (non primary-key) fields modified by the update do not contain the
1.4 misho 11225: ** expected "before" values.
1.5 misho 11226: **
1.4 misho 11227: ** The conflicting row, in this case, is the database row with the matching
11228: ** primary key.
1.5 misho 11229: **
1.4 misho 11230: ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11231: ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11232: ** argument when processing a DELETE or UPDATE change if a row with the
11233: ** required PRIMARY KEY fields is not present in the database.
1.5 misho 11234: **
1.4 misho 11235: ** There is no conflicting row in this case. The results of invoking the
11236: ** sqlite3changeset_conflict() API are undefined.
1.5 misho 11237: **
1.4 misho 11238: ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11239: ** CHANGESET_CONFLICT is passed as the second argument to the conflict
1.5 misho 11240: ** handler while processing an INSERT change if the operation would result
1.4 misho 11241: ** in duplicate primary key values.
1.5 misho 11242: **
1.4 misho 11243: ** The conflicting row in this case is the database row with the matching
11244: ** primary key.
11245: **
11246: ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11247: ** If foreign key handling is enabled, and applying a changeset leaves the
1.5 misho 11248: ** database in a state containing foreign key violations, the conflict
1.4 misho 11249: ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11250: ** exactly once before the changeset is committed. If the conflict handler
11251: ** returns CHANGESET_OMIT, the changes, including those that caused the
11252: ** foreign key constraint violation, are committed. Or, if it returns
11253: ** CHANGESET_ABORT, the changeset is rolled back.
11254: **
11255: ** No current or conflicting row information is provided. The only function
11256: ** it is possible to call on the supplied sqlite3_changeset_iter handle
11257: ** is sqlite3changeset_fk_conflicts().
1.5 misho 11258: **
1.4 misho 11259: ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
1.5 misho 11260: ** If any other constraint violation occurs while applying a change (i.e.
11261: ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
1.4 misho 11262: ** invoked with CHANGESET_CONSTRAINT as the second argument.
1.5 misho 11263: **
1.4 misho 11264: ** There is no conflicting row in this case. The results of invoking the
11265: ** sqlite3changeset_conflict() API are undefined.
11266: **
11267: ** </dl>
11268: */
11269: #define SQLITE_CHANGESET_DATA 1
11270: #define SQLITE_CHANGESET_NOTFOUND 2
11271: #define SQLITE_CHANGESET_CONFLICT 3
11272: #define SQLITE_CHANGESET_CONSTRAINT 4
11273: #define SQLITE_CHANGESET_FOREIGN_KEY 5
11274:
1.5 misho 11275: /*
1.4 misho 11276: ** CAPI3REF: Constants Returned By The Conflict Handler
11277: **
11278: ** A conflict handler callback must return one of the following three values.
11279: **
11280: ** <dl>
11281: ** <dt>SQLITE_CHANGESET_OMIT<dd>
11282: ** If a conflict handler returns this value no special action is taken. The
1.5 misho 11283: ** change that caused the conflict is not applied. The session module
1.4 misho 11284: ** continues to the next change in the changeset.
11285: **
11286: ** <dt>SQLITE_CHANGESET_REPLACE<dd>
11287: ** This value may only be returned if the second argument to the conflict
11288: ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
1.5 misho 11289: ** is not the case, any changes applied so far are rolled back and the
1.4 misho 11290: ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11291: **
11292: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11293: ** handler, then the conflicting row is either updated or deleted, depending
11294: ** on the type of change.
11295: **
11296: ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11297: ** handler, then the conflicting row is removed from the database and a
11298: ** second attempt to apply the change is made. If this second attempt fails,
11299: ** the original row is restored to the database before continuing.
11300: **
11301: ** <dt>SQLITE_CHANGESET_ABORT<dd>
1.5 misho 11302: ** If this value is returned, any changes applied so far are rolled back
1.4 misho 11303: ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11304: ** </dl>
11305: */
11306: #define SQLITE_CHANGESET_OMIT 0
11307: #define SQLITE_CHANGESET_REPLACE 1
11308: #define SQLITE_CHANGESET_ABORT 2
11309:
11310: /*
1.5 misho 11311: ** CAPI3REF: Rebasing changesets
11312: ** EXPERIMENTAL
11313: **
11314: ** Suppose there is a site hosting a database in state S0. And that
11315: ** modifications are made that move that database to state S1 and a
11316: ** changeset recorded (the "local" changeset). Then, a changeset based
11317: ** on S0 is received from another site (the "remote" changeset) and
11318: ** applied to the database. The database is then in state
11319: ** (S1+"remote"), where the exact state depends on any conflict
11320: ** resolution decisions (OMIT or REPLACE) made while applying "remote".
11321: ** Rebasing a changeset is to update it to take those conflict
11322: ** resolution decisions into account, so that the same conflicts
11323: ** do not have to be resolved elsewhere in the network.
11324: **
11325: ** For example, if both the local and remote changesets contain an
11326: ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11327: **
11328: ** local: INSERT INTO t1 VALUES(1, 'v1');
11329: ** remote: INSERT INTO t1 VALUES(1, 'v2');
11330: **
11331: ** and the conflict resolution is REPLACE, then the INSERT change is
11332: ** removed from the local changeset (it was overridden). Or, if the
11333: ** conflict resolution was "OMIT", then the local changeset is modified
11334: ** to instead contain:
11335: **
11336: ** UPDATE t1 SET b = 'v2' WHERE a=1;
11337: **
11338: ** Changes within the local changeset are rebased as follows:
11339: **
11340: ** <dl>
11341: ** <dt>Local INSERT<dd>
11342: ** This may only conflict with a remote INSERT. If the conflict
11343: ** resolution was OMIT, then add an UPDATE change to the rebased
11344: ** changeset. Or, if the conflict resolution was REPLACE, add
11345: ** nothing to the rebased changeset.
11346: **
11347: ** <dt>Local DELETE<dd>
11348: ** This may conflict with a remote UPDATE or DELETE. In both cases the
11349: ** only possible resolution is OMIT. If the remote operation was a
11350: ** DELETE, then add no change to the rebased changeset. If the remote
11351: ** operation was an UPDATE, then the old.* fields of change are updated
11352: ** to reflect the new.* values in the UPDATE.
11353: **
11354: ** <dt>Local UPDATE<dd>
11355: ** This may conflict with a remote UPDATE or DELETE. If it conflicts
11356: ** with a DELETE, and the conflict resolution was OMIT, then the update
11357: ** is changed into an INSERT. Any undefined values in the new.* record
11358: ** from the update change are filled in using the old.* values from
11359: ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11360: ** the UPDATE change is simply omitted from the rebased changeset.
11361: **
11362: ** If conflict is with a remote UPDATE and the resolution is OMIT, then
11363: ** the old.* values are rebased using the new.* values in the remote
11364: ** change. Or, if the resolution is REPLACE, then the change is copied
11365: ** into the rebased changeset with updates to columns also updated by
11366: ** the conflicting remote UPDATE removed. If this means no columns would
11367: ** be updated, the change is omitted.
11368: ** </dl>
11369: **
11370: ** A local change may be rebased against multiple remote changes
11371: ** simultaneously. If a single key is modified by multiple remote
11372: ** changesets, they are combined as follows before the local changeset
11373: ** is rebased:
11374: **
11375: ** <ul>
11376: ** <li> If there has been one or more REPLACE resolutions on a
11377: ** key, it is rebased according to a REPLACE.
11378: **
11379: ** <li> If there have been no REPLACE resolutions on a key, then
11380: ** the local changeset is rebased according to the most recent
11381: ** of the OMIT resolutions.
11382: ** </ul>
11383: **
11384: ** Note that conflict resolutions from multiple remote changesets are
11385: ** combined on a per-field basis, not per-row. This means that in the
11386: ** case of multiple remote UPDATE operations, some fields of a single
11387: ** local change may be rebased for REPLACE while others are rebased for
11388: ** OMIT.
11389: **
11390: ** In order to rebase a local changeset, the remote changeset must first
11391: ** be applied to the local database using sqlite3changeset_apply_v2() and
11392: ** the buffer of rebase information captured. Then:
11393: **
11394: ** <ol>
11395: ** <li> An sqlite3_rebaser object is created by calling
11396: ** sqlite3rebaser_create().
11397: ** <li> The new object is configured with the rebase buffer obtained from
11398: ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11399: ** If the local changeset is to be rebased against multiple remote
11400: ** changesets, then sqlite3rebaser_configure() should be called
11401: ** multiple times, in the same order that the multiple
11402: ** sqlite3changeset_apply_v2() calls were made.
11403: ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11404: ** <li> The sqlite3_rebaser object is deleted by calling
11405: ** sqlite3rebaser_delete().
11406: ** </ol>
11407: */
11408: typedef struct sqlite3_rebaser sqlite3_rebaser;
11409:
11410: /*
11411: ** CAPI3REF: Create a changeset rebaser object.
11412: ** EXPERIMENTAL
11413: **
11414: ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11415: ** point to the new object and return SQLITE_OK. Otherwise, if an error
11416: ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11417: ** to NULL.
11418: */
11419: SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11420:
11421: /*
11422: ** CAPI3REF: Configure a changeset rebaser object.
11423: ** EXPERIMENTAL
11424: **
11425: ** Configure the changeset rebaser object to rebase changesets according
11426: ** to the conflict resolutions described by buffer pRebase (size nRebase
11427: ** bytes), which must have been obtained from a previous call to
11428: ** sqlite3changeset_apply_v2().
11429: */
11430: SQLITE_API int sqlite3rebaser_configure(
11431: sqlite3_rebaser*,
11432: int nRebase, const void *pRebase
11433: );
11434:
11435: /*
11436: ** CAPI3REF: Rebase a changeset
11437: ** EXPERIMENTAL
11438: **
11439: ** Argument pIn must point to a buffer containing a changeset nIn bytes
11440: ** in size. This function allocates and populates a buffer with a copy
11441: ** of the changeset rebased according to the configuration of the
11442: ** rebaser object passed as the first argument. If successful, (*ppOut)
11443: ** is set to point to the new buffer containing the rebased changeset and
11444: ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
11445: ** responsibility of the caller to eventually free the new buffer using
11446: ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
11447: ** are set to zero and an SQLite error code returned.
11448: */
11449: SQLITE_API int sqlite3rebaser_rebase(
11450: sqlite3_rebaser*,
11451: int nIn, const void *pIn,
11452: int *pnOut, void **ppOut
11453: );
11454:
11455: /*
11456: ** CAPI3REF: Delete a changeset rebaser object.
11457: ** EXPERIMENTAL
11458: **
11459: ** Delete the changeset rebaser object and all associated resources. There
11460: ** should be one call to this function for each successful invocation
11461: ** of sqlite3rebaser_create().
11462: */
11463: SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
11464:
11465: /*
1.4 misho 11466: ** CAPI3REF: Streaming Versions of API functions.
11467: **
1.5 misho 11468: ** The six streaming API xxx_strm() functions serve similar purposes to the
1.4 misho 11469: ** corresponding non-streaming API functions:
11470: **
11471: ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11472: ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
1.5 misho 11473: ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
11474: ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
11475: ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
11476: ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
11477: ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
11478: ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
11479: ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
1.4 misho 11480: ** </table>
11481: **
11482: ** Non-streaming functions that accept changesets (or patchsets) as input
1.5 misho 11483: ** require that the entire changeset be stored in a single buffer in memory.
11484: ** Similarly, those that return a changeset or patchset do so by returning
11485: ** a pointer to a single large buffer allocated using sqlite3_malloc().
11486: ** Normally this is convenient. However, if an application running in a
1.4 misho 11487: ** low-memory environment is required to handle very large changesets, the
11488: ** large contiguous memory allocations required can become onerous.
11489: **
11490: ** In order to avoid this problem, instead of a single large buffer, input
11491: ** is passed to a streaming API functions by way of a callback function that
11492: ** the sessions module invokes to incrementally request input data as it is
11493: ** required. In all cases, a pair of API function parameters such as
11494: **
11495: ** <pre>
11496: ** int nChangeset,
11497: ** void *pChangeset,
11498: ** </pre>
11499: **
11500: ** Is replaced by:
11501: **
11502: ** <pre>
11503: ** int (*xInput)(void *pIn, void *pData, int *pnData),
11504: ** void *pIn,
11505: ** </pre>
11506: **
11507: ** Each time the xInput callback is invoked by the sessions module, the first
1.5 misho 11508: ** argument passed is a copy of the supplied pIn context pointer. The second
11509: ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
11510: ** error occurs the xInput method should copy up to (*pnData) bytes of data
11511: ** into the buffer and set (*pnData) to the actual number of bytes copied
11512: ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11513: ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
1.4 misho 11514: ** error code should be returned. In all cases, if an xInput callback returns
11515: ** an error, all processing is abandoned and the streaming API function
11516: ** returns a copy of the error code to the caller.
11517: **
11518: ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11519: ** invoked by the sessions module at any point during the lifetime of the
11520: ** iterator. If such an xInput callback returns an error, the iterator enters
1.5 misho 11521: ** an error state, whereby all subsequent calls to iterator functions
1.4 misho 11522: ** immediately fail with the same error code as returned by xInput.
11523: **
11524: ** Similarly, streaming API functions that return changesets (or patchsets)
11525: ** return them in chunks by way of a callback function instead of via a
11526: ** pointer to a single large buffer. In this case, a pair of parameters such
11527: ** as:
11528: **
11529: ** <pre>
11530: ** int *pnChangeset,
11531: ** void **ppChangeset,
11532: ** </pre>
11533: **
11534: ** Is replaced by:
11535: **
11536: ** <pre>
11537: ** int (*xOutput)(void *pOut, const void *pData, int nData),
11538: ** void *pOut
11539: ** </pre>
11540: **
11541: ** The xOutput callback is invoked zero or more times to return data to
11542: ** the application. The first parameter passed to each call is a copy of the
11543: ** pOut pointer supplied by the application. The second parameter, pData,
11544: ** points to a buffer nData bytes in size containing the chunk of output
11545: ** data being returned. If the xOutput callback successfully processes the
11546: ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11547: ** it should return some other SQLite error code. In this case processing
11548: ** is immediately abandoned and the streaming API function returns a copy
11549: ** of the xOutput error code to the application.
11550: **
1.5 misho 11551: ** The sessions module never invokes an xOutput callback with the third
1.4 misho 11552: ** parameter set to a value less than or equal to zero. Other than this,
11553: ** no guarantees are made as to the size of the chunks of data returned.
11554: */
1.5 misho 11555: SQLITE_API int sqlite3changeset_apply_strm(
1.4 misho 11556: sqlite3 *db, /* Apply change to "main" db of this handle */
11557: int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11558: void *pIn, /* First arg for xInput */
11559: int(*xFilter)(
11560: void *pCtx, /* Copy of sixth arg to _apply() */
11561: const char *zTab /* Table name */
11562: ),
11563: int(*xConflict)(
11564: void *pCtx, /* Copy of sixth arg to _apply() */
11565: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11566: sqlite3_changeset_iter *p /* Handle describing change and conflict */
11567: ),
11568: void *pCtx /* First argument passed to xConflict */
11569: );
1.5 misho 11570: SQLITE_API int sqlite3changeset_apply_v2_strm(
11571: sqlite3 *db, /* Apply change to "main" db of this handle */
11572: int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11573: void *pIn, /* First arg for xInput */
11574: int(*xFilter)(
11575: void *pCtx, /* Copy of sixth arg to _apply() */
11576: const char *zTab /* Table name */
11577: ),
11578: int(*xConflict)(
11579: void *pCtx, /* Copy of sixth arg to _apply() */
11580: int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11581: sqlite3_changeset_iter *p /* Handle describing change and conflict */
11582: ),
11583: void *pCtx, /* First argument passed to xConflict */
11584: void **ppRebase, int *pnRebase,
11585: int flags
11586: );
11587: SQLITE_API int sqlite3changeset_concat_strm(
1.4 misho 11588: int (*xInputA)(void *pIn, void *pData, int *pnData),
11589: void *pInA,
11590: int (*xInputB)(void *pIn, void *pData, int *pnData),
11591: void *pInB,
11592: int (*xOutput)(void *pOut, const void *pData, int nData),
11593: void *pOut
11594: );
1.5 misho 11595: SQLITE_API int sqlite3changeset_invert_strm(
1.4 misho 11596: int (*xInput)(void *pIn, void *pData, int *pnData),
11597: void *pIn,
11598: int (*xOutput)(void *pOut, const void *pData, int nData),
11599: void *pOut
11600: );
1.5 misho 11601: SQLITE_API int sqlite3changeset_start_strm(
1.4 misho 11602: sqlite3_changeset_iter **pp,
11603: int (*xInput)(void *pIn, void *pData, int *pnData),
11604: void *pIn
11605: );
1.5 misho 11606: SQLITE_API int sqlite3changeset_start_v2_strm(
11607: sqlite3_changeset_iter **pp,
11608: int (*xInput)(void *pIn, void *pData, int *pnData),
11609: void *pIn,
11610: int flags
11611: );
11612: SQLITE_API int sqlite3session_changeset_strm(
1.4 misho 11613: sqlite3_session *pSession,
11614: int (*xOutput)(void *pOut, const void *pData, int nData),
11615: void *pOut
11616: );
1.5 misho 11617: SQLITE_API int sqlite3session_patchset_strm(
1.4 misho 11618: sqlite3_session *pSession,
11619: int (*xOutput)(void *pOut, const void *pData, int nData),
11620: void *pOut
11621: );
1.5 misho 11622: SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
1.4 misho 11623: int (*xInput)(void *pIn, void *pData, int *pnData),
11624: void *pIn
11625: );
1.5 misho 11626: SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11627: int (*xOutput)(void *pOut, const void *pData, int nData),
1.4 misho 11628: void *pOut
11629: );
1.5 misho 11630: SQLITE_API int sqlite3rebaser_rebase_strm(
11631: sqlite3_rebaser *pRebaser,
11632: int (*xInput)(void *pIn, void *pData, int *pnData),
11633: void *pIn,
11634: int (*xOutput)(void *pOut, const void *pData, int nData),
11635: void *pOut
11636: );
11637:
11638: /*
11639: ** CAPI3REF: Configure global parameters
11640: **
11641: ** The sqlite3session_config() interface is used to make global configuration
11642: ** changes to the sessions module in order to tune it to the specific needs
11643: ** of the application.
11644: **
11645: ** The sqlite3session_config() interface is not threadsafe. If it is invoked
11646: ** while any other thread is inside any other sessions method then the
11647: ** results are undefined. Furthermore, if it is invoked after any sessions
11648: ** related objects have been created, the results are also undefined.
11649: **
11650: ** The first argument to the sqlite3session_config() function must be one
11651: ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11652: ** interpretation of the (void*) value passed as the second parameter and
11653: ** the effect of calling this function depends on the value of the first
11654: ** parameter.
11655: **
11656: ** <dl>
11657: ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11658: ** By default, the sessions module streaming interfaces attempt to input
11659: ** and output data in approximately 1 KiB chunks. This operand may be used
11660: ** to set and query the value of this configuration setting. The pointer
11661: ** passed as the second argument must point to a value of type (int).
11662: ** If this value is greater than 0, it is used as the new streaming data
11663: ** chunk size for both input and output. Before returning, the (int) value
11664: ** pointed to by pArg is set to the final value of the streaming interface
11665: ** chunk size.
11666: ** </dl>
11667: **
11668: ** This function returns SQLITE_OK if successful, or an SQLite error code
11669: ** otherwise.
11670: */
11671: SQLITE_API int sqlite3session_config(int op, void *pArg);
1.4 misho 11672:
1.5 misho 11673: /*
11674: ** CAPI3REF: Values for sqlite3session_config().
11675: */
11676: #define SQLITE_SESSION_CONFIG_STRMSIZE 1
1.4 misho 11677:
11678: /*
11679: ** Make sure we can call this stuff from C++.
11680: */
11681: #ifdef __cplusplus
11682: }
11683: #endif
11684:
11685: #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11686:
11687: /******** End of sqlite3session.h *********/
11688: /******** Begin file fts5.h *********/
11689: /*
11690: ** 2014 May 31
11691: **
11692: ** The author disclaims copyright to this source code. In place of
11693: ** a legal notice, here is a blessing:
11694: **
11695: ** May you do good and not evil.
11696: ** May you find forgiveness for yourself and forgive others.
11697: ** May you share freely, never taking more than you give.
11698: **
11699: ******************************************************************************
11700: **
1.5 misho 11701: ** Interfaces to extend FTS5. Using the interfaces defined in this file,
1.4 misho 11702: ** FTS5 may be extended with:
11703: **
11704: ** * custom tokenizers, and
11705: ** * custom auxiliary functions.
11706: */
11707:
11708:
11709: #ifndef _FTS5_H
11710: #define _FTS5_H
11711:
11712:
11713: #ifdef __cplusplus
11714: extern "C" {
11715: #endif
11716:
11717: /*************************************************************************
11718: ** CUSTOM AUXILIARY FUNCTIONS
11719: **
11720: ** Virtual table implementations may overload SQL functions by implementing
11721: ** the sqlite3_module.xFindFunction() method.
11722: */
11723:
11724: typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11725: typedef struct Fts5Context Fts5Context;
11726: typedef struct Fts5PhraseIter Fts5PhraseIter;
11727:
11728: typedef void (*fts5_extension_function)(
11729: const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11730: Fts5Context *pFts, /* First arg to pass to pApi functions */
11731: sqlite3_context *pCtx, /* Context for returning result/error */
11732: int nVal, /* Number of values in apVal[] array */
11733: sqlite3_value **apVal /* Array of trailing arguments */
11734: );
11735:
11736: struct Fts5PhraseIter {
11737: const unsigned char *a;
11738: const unsigned char *b;
11739: };
11740:
11741: /*
11742: ** EXTENSION API FUNCTIONS
11743: **
11744: ** xUserData(pFts):
1.5 misho 11745: ** Return a copy of the context pointer the extension function was
1.4 misho 11746: ** registered with.
11747: **
11748: ** xColumnTotalSize(pFts, iCol, pnToken):
11749: ** If parameter iCol is less than zero, set output variable *pnToken
11750: ** to the total number of tokens in the FTS5 table. Or, if iCol is
11751: ** non-negative but less than the number of columns in the table, return
1.5 misho 11752: ** the total number of tokens in column iCol, considering all rows in
1.4 misho 11753: ** the FTS5 table.
11754: **
11755: ** If parameter iCol is greater than or equal to the number of columns
11756: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
1.5 misho 11757: ** an OOM condition or IO error), an appropriate SQLite error code is
1.4 misho 11758: ** returned.
11759: **
11760: ** xColumnCount(pFts):
11761: ** Return the number of columns in the table.
11762: **
11763: ** xColumnSize(pFts, iCol, pnToken):
11764: ** If parameter iCol is less than zero, set output variable *pnToken
11765: ** to the total number of tokens in the current row. Or, if iCol is
11766: ** non-negative but less than the number of columns in the table, set
11767: ** *pnToken to the number of tokens in column iCol of the current row.
11768: **
11769: ** If parameter iCol is greater than or equal to the number of columns
11770: ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
1.5 misho 11771: ** an OOM condition or IO error), an appropriate SQLite error code is
1.4 misho 11772: ** returned.
11773: **
11774: ** This function may be quite inefficient if used with an FTS5 table
11775: ** created with the "columnsize=0" option.
11776: **
11777: ** xColumnText:
11778: ** This function attempts to retrieve the text of column iCol of the
11779: ** current document. If successful, (*pz) is set to point to a buffer
11780: ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11781: ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11782: ** if an error occurs, an SQLite error code is returned and the final values
11783: ** of (*pz) and (*pn) are undefined.
11784: **
11785: ** xPhraseCount:
11786: ** Returns the number of phrases in the current query expression.
11787: **
11788: ** xPhraseSize:
11789: ** Returns the number of tokens in phrase iPhrase of the query. Phrases
11790: ** are numbered starting from zero.
11791: **
11792: ** xInstCount:
11793: ** Set *pnInst to the total number of occurrences of all phrases within
11794: ** the query within the current row. Return SQLITE_OK if successful, or
11795: ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11796: **
11797: ** This API can be quite slow if used with an FTS5 table created with the
1.5 misho 11798: ** "detail=none" or "detail=column" option. If the FTS5 table is created
11799: ** with either "detail=none" or "detail=column" and "content=" option
1.4 misho 11800: ** (i.e. if it is a contentless table), then this API always returns 0.
11801: **
11802: ** xInst:
11803: ** Query for the details of phrase match iIdx within the current row.
11804: ** Phrase matches are numbered starting from zero, so the iIdx argument
11805: ** should be greater than or equal to zero and smaller than the value
11806: ** output by xInstCount().
11807: **
11808: ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11809: ** to the column in which it occurs and *piOff the token offset of the
1.5 misho 11810: ** first token of the phrase. Returns SQLITE_OK if successful, or an error
11811: ** code (i.e. SQLITE_NOMEM) if an error occurs.
1.4 misho 11812: **
11813: ** This API can be quite slow if used with an FTS5 table created with the
1.5 misho 11814: ** "detail=none" or "detail=column" option.
1.4 misho 11815: **
11816: ** xRowid:
11817: ** Returns the rowid of the current row.
11818: **
11819: ** xTokenize:
11820: ** Tokenize text using the tokenizer belonging to the FTS5 table.
11821: **
11822: ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11823: ** This API function is used to query the FTS table for phrase iPhrase
11824: ** of the current query. Specifically, a query equivalent to:
11825: **
11826: ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11827: **
11828: ** with $p set to a phrase equivalent to the phrase iPhrase of the
11829: ** current query is executed. Any column filter that applies to
1.5 misho 11830: ** phrase iPhrase of the current query is included in $p. For each
11831: ** row visited, the callback function passed as the fourth argument
11832: ** is invoked. The context and API objects passed to the callback
1.4 misho 11833: ** function may be used to access the properties of each matched row.
1.5 misho 11834: ** Invoking Api.xUserData() returns a copy of the pointer passed as
1.4 misho 11835: ** the third argument to pUserData.
11836: **
11837: ** If the callback function returns any value other than SQLITE_OK, the
11838: ** query is abandoned and the xQueryPhrase function returns immediately.
11839: ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11840: ** Otherwise, the error code is propagated upwards.
11841: **
11842: ** If the query runs to completion without incident, SQLITE_OK is returned.
11843: ** Or, if some error occurs before the query completes or is aborted by
11844: ** the callback, an SQLite error code is returned.
11845: **
11846: **
11847: ** xSetAuxdata(pFts5, pAux, xDelete)
11848: **
1.5 misho 11849: ** Save the pointer passed as the second argument as the extension function's
1.4 misho 11850: ** "auxiliary data". The pointer may then be retrieved by the current or any
11851: ** future invocation of the same fts5 extension function made as part of
1.5 misho 11852: ** the same MATCH query using the xGetAuxdata() API.
1.4 misho 11853: **
11854: ** Each extension function is allocated a single auxiliary data slot for
1.5 misho 11855: ** each FTS query (MATCH expression). If the extension function is invoked
11856: ** more than once for a single FTS query, then all invocations share a
1.4 misho 11857: ** single auxiliary data context.
11858: **
11859: ** If there is already an auxiliary data pointer when this function is
11860: ** invoked, then it is replaced by the new pointer. If an xDelete callback
11861: ** was specified along with the original pointer, it is invoked at this
11862: ** point.
11863: **
11864: ** The xDelete callback, if one is specified, is also invoked on the
11865: ** auxiliary data pointer after the FTS5 query has finished.
11866: **
1.5 misho 11867: ** If an error (e.g. an OOM condition) occurs within this function,
1.4 misho 11868: ** the auxiliary data is set to NULL and an error code returned. If the
11869: ** xDelete parameter was not NULL, it is invoked on the auxiliary data
11870: ** pointer before returning.
11871: **
11872: **
11873: ** xGetAuxdata(pFts5, bClear)
11874: **
1.5 misho 11875: ** Returns the current auxiliary data pointer for the fts5 extension
1.4 misho 11876: ** function. See the xSetAuxdata() method for details.
11877: **
11878: ** If the bClear argument is non-zero, then the auxiliary data is cleared
11879: ** (set to NULL) before this function returns. In this case the xDelete,
11880: ** if any, is not invoked.
11881: **
11882: **
11883: ** xRowCount(pFts5, pnRow)
11884: **
11885: ** This function is used to retrieve the total number of rows in the table.
11886: ** In other words, the same value that would be returned by:
11887: **
11888: ** SELECT count(*) FROM ftstable;
11889: **
11890: ** xPhraseFirst()
11891: ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11892: ** method, to iterate through all instances of a single query phrase within
11893: ** the current row. This is the same information as is accessible via the
11894: ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
1.5 misho 11895: ** to use, this API may be faster under some circumstances. To iterate
1.4 misho 11896: ** through instances of phrase iPhrase, use the following code:
11897: **
11898: ** Fts5PhraseIter iter;
11899: ** int iCol, iOff;
11900: ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11901: ** iCol>=0;
11902: ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11903: ** ){
11904: ** // An instance of phrase iPhrase at offset iOff of column iCol
11905: ** }
11906: **
11907: ** The Fts5PhraseIter structure is defined above. Applications should not
11908: ** modify this structure directly - it should only be used as shown above
11909: ** with the xPhraseFirst() and xPhraseNext() API methods (and by
11910: ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11911: **
11912: ** This API can be quite slow if used with an FTS5 table created with the
1.5 misho 11913: ** "detail=none" or "detail=column" option. If the FTS5 table is created
11914: ** with either "detail=none" or "detail=column" and "content=" option
1.4 misho 11915: ** (i.e. if it is a contentless table), then this API always iterates
11916: ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11917: **
11918: ** xPhraseNext()
11919: ** See xPhraseFirst above.
11920: **
11921: ** xPhraseFirstColumn()
11922: ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11923: ** and xPhraseNext() APIs described above. The difference is that instead
11924: ** of iterating through all instances of a phrase in the current row, these
11925: ** APIs are used to iterate through the set of columns in the current row
11926: ** that contain one or more instances of a specified phrase. For example:
11927: **
11928: ** Fts5PhraseIter iter;
11929: ** int iCol;
11930: ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11931: ** iCol>=0;
11932: ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11933: ** ){
11934: ** // Column iCol contains at least one instance of phrase iPhrase
11935: ** }
11936: **
11937: ** This API can be quite slow if used with an FTS5 table created with the
1.5 misho 11938: ** "detail=none" option. If the FTS5 table is created with either
11939: ** "detail=none" "content=" option (i.e. if it is a contentless table),
11940: ** then this API always iterates through an empty set (all calls to
1.4 misho 11941: ** xPhraseFirstColumn() set iCol to -1).
11942: **
11943: ** The information accessed using this API and its companion
11944: ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11945: ** (or xInst/xInstCount). The chief advantage of this API is that it is
11946: ** significantly more efficient than those alternatives when used with
1.5 misho 11947: ** "detail=column" tables.
1.4 misho 11948: **
11949: ** xPhraseNextColumn()
11950: ** See xPhraseFirstColumn above.
11951: */
11952: struct Fts5ExtensionApi {
11953: int iVersion; /* Currently always set to 3 */
11954:
11955: void *(*xUserData)(Fts5Context*);
11956:
11957: int (*xColumnCount)(Fts5Context*);
11958: int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11959: int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11960:
1.5 misho 11961: int (*xTokenize)(Fts5Context*,
1.4 misho 11962: const char *pText, int nText, /* Text to tokenize */
11963: void *pCtx, /* Context passed to xToken() */
11964: int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11965: );
11966:
11967: int (*xPhraseCount)(Fts5Context*);
11968: int (*xPhraseSize)(Fts5Context*, int iPhrase);
11969:
11970: int (*xInstCount)(Fts5Context*, int *pnInst);
11971: int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11972:
11973: sqlite3_int64 (*xRowid)(Fts5Context*);
11974: int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11975: int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11976:
11977: int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11978: int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11979: );
11980: int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11981: void *(*xGetAuxdata)(Fts5Context*, int bClear);
11982:
11983: int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11984: void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11985:
11986: int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11987: void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11988: };
11989:
1.5 misho 11990: /*
1.4 misho 11991: ** CUSTOM AUXILIARY FUNCTIONS
11992: *************************************************************************/
11993:
11994: /*************************************************************************
11995: ** CUSTOM TOKENIZERS
11996: **
1.5 misho 11997: ** Applications may also register custom tokenizer types. A tokenizer
11998: ** is registered by providing fts5 with a populated instance of the
1.4 misho 11999: ** following structure. All structure methods must be defined, setting
12000: ** any member of the fts5_tokenizer struct to NULL leads to undefined
12001: ** behaviour. The structure methods are expected to function as follows:
12002: **
12003: ** xCreate:
12004: ** This function is used to allocate and initialize a tokenizer instance.
12005: ** A tokenizer instance is required to actually tokenize text.
12006: **
12007: ** The first argument passed to this function is a copy of the (void*)
12008: ** pointer provided by the application when the fts5_tokenizer object
1.5 misho 12009: ** was registered with FTS5 (the third argument to xCreateTokenizer()).
1.4 misho 12010: ** The second and third arguments are an array of nul-terminated strings
12011: ** containing the tokenizer arguments, if any, specified following the
12012: ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12013: ** to create the FTS5 table.
12014: **
1.5 misho 12015: ** The final argument is an output variable. If successful, (*ppOut)
1.4 misho 12016: ** should be set to point to the new tokenizer handle and SQLITE_OK
12017: ** returned. If an error occurs, some value other than SQLITE_OK should
1.5 misho 12018: ** be returned. In this case, fts5 assumes that the final value of *ppOut
1.4 misho 12019: ** is undefined.
12020: **
12021: ** xDelete:
12022: ** This function is invoked to delete a tokenizer handle previously
12023: ** allocated using xCreate(). Fts5 guarantees that this function will
12024: ** be invoked exactly once for each successful call to xCreate().
12025: **
12026: ** xTokenize:
1.5 misho 12027: ** This function is expected to tokenize the nText byte string indicated
1.4 misho 12028: ** by argument pText. pText may or may not be nul-terminated. The first
12029: ** argument passed to this function is a pointer to an Fts5Tokenizer object
12030: ** returned by an earlier call to xCreate().
12031: **
12032: ** The second argument indicates the reason that FTS5 is requesting
12033: ** tokenization of the supplied text. This is always one of the following
12034: ** four values:
12035: **
12036: ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12037: ** or removed from the FTS table. The tokenizer is being invoked to
12038: ** determine the set of tokens to add to (or delete from) the
12039: ** FTS index.
12040: **
1.5 misho 12041: ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12042: ** against the FTS index. The tokenizer is being called to tokenize
1.4 misho 12043: ** a bareword or quoted string specified as part of the query.
12044: **
12045: ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12046: ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12047: ** followed by a "*" character, indicating that the last token
12048: ** returned by the tokenizer will be treated as a token prefix.
12049: **
1.5 misho 12050: ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
1.4 misho 12051: ** satisfy an fts5_api.xTokenize() request made by an auxiliary
12052: ** function. Or an fts5_api.xColumnSize() request made by the same
1.5 misho 12053: ** on a columnsize=0 database.
1.4 misho 12054: ** </ul>
12055: **
12056: ** For each token in the input string, the supplied callback xToken() must
12057: ** be invoked. The first argument to it should be a copy of the pointer
12058: ** passed as the second argument to xTokenize(). The third and fourth
12059: ** arguments are a pointer to a buffer containing the token text, and the
12060: ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12061: ** of the first byte of and first byte immediately following the text from
12062: ** which the token is derived within the input.
12063: **
12064: ** The second argument passed to the xToken() callback ("tflags") should
1.5 misho 12065: ** normally be set to 0. The exception is if the tokenizer supports
1.4 misho 12066: ** synonyms. In this case see the discussion below for details.
12067: **
1.5 misho 12068: ** FTS5 assumes the xToken() callback is invoked for each token in the
1.4 misho 12069: ** order that they occur within the input text.
12070: **
12071: ** If an xToken() callback returns any value other than SQLITE_OK, then
12072: ** the tokenization should be abandoned and the xTokenize() method should
12073: ** immediately return a copy of the xToken() return value. Or, if the
12074: ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12075: ** if an error occurs with the xTokenize() implementation itself, it
12076: ** may abandon the tokenization and return any error code other than
12077: ** SQLITE_OK or SQLITE_DONE.
12078: **
12079: ** SYNONYM SUPPORT
12080: **
12081: ** Custom tokenizers may also support synonyms. Consider a case in which a
1.5 misho 12082: ** user wishes to query for a phrase such as "first place". Using the
1.4 misho 12083: ** built-in tokenizers, the FTS5 query 'first + place' will match instances
12084: ** of "first place" within the document set, but not alternative forms
12085: ** such as "1st place". In some applications, it would be better to match
12086: ** all instances of "first place" or "1st place" regardless of which form
12087: ** the user specified in the MATCH query text.
12088: **
12089: ** There are several ways to approach this in FTS5:
12090: **
1.5 misho 12091: ** <ol><li> By mapping all synonyms to a single token. In this case, using
12092: ** the above example, this means that the tokenizer returns the
1.4 misho 12093: ** same token for inputs "first" and "1st". Say that token is in
12094: ** fact "first", so that when the user inserts the document "I won
12095: ** 1st place" entries are added to the index for tokens "i", "won",
12096: ** "first" and "place". If the user then queries for '1st + place',
12097: ** the tokenizer substitutes "first" for "1st" and the query works
12098: ** as expected.
12099: **
1.5 misho 12100: ** <li> By querying the index for all synonyms of each query term
12101: ** separately. In this case, when tokenizing query text, the
12102: ** tokenizer may provide multiple synonyms for a single term
12103: ** within the document. FTS5 then queries the index for each
12104: ** synonym individually. For example, faced with the query:
1.4 misho 12105: **
12106: ** <codeblock>
12107: ** ... MATCH 'first place'</codeblock>
12108: **
12109: ** the tokenizer offers both "1st" and "first" as synonyms for the
1.5 misho 12110: ** first token in the MATCH query and FTS5 effectively runs a query
1.4 misho 12111: ** similar to:
12112: **
12113: ** <codeblock>
12114: ** ... MATCH '(first OR 1st) place'</codeblock>
12115: **
12116: ** except that, for the purposes of auxiliary functions, the query
1.5 misho 12117: ** still appears to contain just two phrases - "(first OR 1st)"
1.4 misho 12118: ** being treated as a single phrase.
12119: **
12120: ** <li> By adding multiple synonyms for a single term to the FTS index.
12121: ** Using this method, when tokenizing document text, the tokenizer
1.5 misho 12122: ** provides multiple synonyms for each token. So that when a
1.4 misho 12123: ** document such as "I won first place" is tokenized, entries are
12124: ** added to the FTS index for "i", "won", "first", "1st" and
12125: ** "place".
12126: **
12127: ** This way, even if the tokenizer does not provide synonyms
1.5 misho 12128: ** when tokenizing query text (it should not - to do so would be
12129: ** inefficient), it doesn't matter if the user queries for
12130: ** 'first + place' or '1st + place', as there are entries in the
1.4 misho 12131: ** FTS index corresponding to both forms of the first token.
12132: ** </ol>
12133: **
12134: ** Whether it is parsing document or query text, any call to xToken that
12135: ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12136: ** is considered to supply a synonym for the previous token. For example,
12137: ** when parsing the document "I won first place", a tokenizer that supports
12138: ** synonyms would call xToken() 5 times, as follows:
12139: **
12140: ** <codeblock>
12141: ** xToken(pCtx, 0, "i", 1, 0, 1);
12142: ** xToken(pCtx, 0, "won", 3, 2, 5);
12143: ** xToken(pCtx, 0, "first", 5, 6, 11);
12144: ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12145: ** xToken(pCtx, 0, "place", 5, 12, 17);
12146: **</codeblock>
12147: **
12148: ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12149: ** xToken() is called. Multiple synonyms may be specified for a single token
1.5 misho 12150: ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
1.4 misho 12151: ** There is no limit to the number of synonyms that may be provided for a
12152: ** single token.
12153: **
1.5 misho 12154: ** In many cases, method (1) above is the best approach. It does not add
1.4 misho 12155: ** extra data to the FTS index or require FTS5 to query for multiple terms,
12156: ** so it is efficient in terms of disk space and query speed. However, it
12157: ** does not support prefix queries very well. If, as suggested above, the
1.5 misho 12158: ** token "first" is substituted for "1st" by the tokenizer, then the query:
1.4 misho 12159: **
12160: ** <codeblock>
12161: ** ... MATCH '1s*'</codeblock>
12162: **
12163: ** will not match documents that contain the token "1st" (as the tokenizer
12164: ** will probably not map "1s" to any prefix of "first").
12165: **
1.5 misho 12166: ** For full prefix support, method (3) may be preferred. In this case,
1.4 misho 12167: ** because the index contains entries for both "first" and "1st", prefix
12168: ** queries such as 'fi*' or '1s*' will match correctly. However, because
12169: ** extra entries are added to the FTS index, this method uses more space
12170: ** within the database.
12171: **
12172: ** Method (2) offers a midpoint between (1) and (3). Using this method,
1.5 misho 12173: ** a query such as '1s*' will match documents that contain the literal
1.4 misho 12174: ** token "1st", but not "first" (assuming the tokenizer is not able to
12175: ** provide synonyms for prefixes). However, a non-prefix query like '1st'
12176: ** will match against "1st" and "first". This method does not require
1.5 misho 12177: ** extra disk space, as no extra entries are added to the FTS index.
1.4 misho 12178: ** On the other hand, it may require more CPU cycles to run MATCH queries,
12179: ** as separate queries of the FTS index are required for each synonym.
12180: **
12181: ** When using methods (2) or (3), it is important that the tokenizer only
12182: ** provide synonyms when tokenizing document text (method (2)) or query
12183: ** text (method (3)), not both. Doing so will not cause any errors, but is
12184: ** inefficient.
12185: */
12186: typedef struct Fts5Tokenizer Fts5Tokenizer;
12187: typedef struct fts5_tokenizer fts5_tokenizer;
12188: struct fts5_tokenizer {
12189: int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12190: void (*xDelete)(Fts5Tokenizer*);
1.5 misho 12191: int (*xTokenize)(Fts5Tokenizer*,
1.4 misho 12192: void *pCtx,
12193: int flags, /* Mask of FTS5_TOKENIZE_* flags */
1.5 misho 12194: const char *pText, int nText,
1.4 misho 12195: int (*xToken)(
12196: void *pCtx, /* Copy of 2nd argument to xTokenize() */
12197: int tflags, /* Mask of FTS5_TOKEN_* flags */
12198: const char *pToken, /* Pointer to buffer containing token */
12199: int nToken, /* Size of token in bytes */
12200: int iStart, /* Byte offset of token within input text */
12201: int iEnd /* Byte offset of end of token within input text */
12202: )
12203: );
12204: };
12205:
12206: /* Flags that may be passed as the third argument to xTokenize() */
12207: #define FTS5_TOKENIZE_QUERY 0x0001
12208: #define FTS5_TOKENIZE_PREFIX 0x0002
12209: #define FTS5_TOKENIZE_DOCUMENT 0x0004
12210: #define FTS5_TOKENIZE_AUX 0x0008
12211:
12212: /* Flags that may be passed by the tokenizer implementation back to FTS5
12213: ** as the third argument to the supplied xToken callback. */
12214: #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12215:
12216: /*
12217: ** END OF CUSTOM TOKENIZERS
12218: *************************************************************************/
12219:
12220: /*************************************************************************
12221: ** FTS5 EXTENSION REGISTRATION API
12222: */
12223: typedef struct fts5_api fts5_api;
12224: struct fts5_api {
12225: int iVersion; /* Currently always set to 2 */
12226:
12227: /* Create a new tokenizer */
12228: int (*xCreateTokenizer)(
12229: fts5_api *pApi,
12230: const char *zName,
12231: void *pContext,
12232: fts5_tokenizer *pTokenizer,
12233: void (*xDestroy)(void*)
12234: );
12235:
12236: /* Find an existing tokenizer */
12237: int (*xFindTokenizer)(
12238: fts5_api *pApi,
12239: const char *zName,
12240: void **ppContext,
12241: fts5_tokenizer *pTokenizer
12242: );
12243:
12244: /* Create a new auxiliary function */
12245: int (*xCreateFunction)(
12246: fts5_api *pApi,
12247: const char *zName,
12248: void *pContext,
12249: fts5_extension_function xFunction,
12250: void (*xDestroy)(void*)
12251: );
12252: };
12253:
12254: /*
12255: ** END OF REGISTRATION API
12256: *************************************************************************/
12257:
12258: #ifdef __cplusplus
12259: } /* end of the 'extern "C"' block */
12260: #endif
12261:
12262: #endif /* _FTS5_H */
12263:
12264: /******** End of fts5.h *********/
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