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File: [ELWIX - Embedded LightWeight unIX -] / elwix / files / sqlite / dist / sqlite3.h
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Tue Mar 16 16:40:43 2021 UTC (3 years, 4 months ago) by misho
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sqlite ver 3.35.1

1: /* 2: ** 2001-09-15 3: ** 4: ** The author disclaims copyright to this source code. In place of 5: ** a legal notice, here is a blessing: 6: ** 7: ** May you do good and not evil. 8: ** May you find forgiveness for yourself and forgive others. 9: ** May you share freely, never taking more than you give. 10: ** 11: ************************************************************************* 12: ** This header file defines the interface that the SQLite library 13: ** presents to client programs. If a C-function, structure, datatype, 14: ** or constant definition does not appear in this file, then it is 15: ** not a published API of SQLite, is subject to change without 16: ** notice, and should not be referenced by programs that use SQLite. 17: ** 18: ** Some of the definitions that are in this file are marked as 19: ** "experimental". Experimental interfaces are normally new 20: ** features recently added to SQLite. We do not anticipate changes 21: ** to experimental interfaces but reserve the right to make minor changes 22: ** if experience from use "in the wild" suggest such changes are prudent. 23: ** 24: ** The official C-language API documentation for SQLite is derived 25: ** from comments in this file. This file is the authoritative source 26: ** on how SQLite interfaces are supposed to operate. 27: ** 28: ** The name of this file under configuration management is "sqlite.h.in". 29: ** The makefile makes some minor changes to this file (such as inserting 30: ** the version number) and changes its name to "sqlite3.h" as 31: ** part of the build process. 32: */ 33: #ifndef SQLITE3_H 34: #define SQLITE3_H 35: #include <stdarg.h> /* Needed for the definition of va_list */ 36: 37: /* 38: ** Make sure we can call this stuff from C++. 39: */ 40: #ifdef __cplusplus 41: extern "C" { 42: #endif 43: 44: 45: /* 46: ** Provide the ability to override linkage features of the interface. 47: */ 48: #ifndef SQLITE_EXTERN 49: # define SQLITE_EXTERN extern 50: #endif 51: #ifndef SQLITE_API 52: # define SQLITE_API 53: #endif 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 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 73: ** should not use deprecated interfaces - they are supported for backwards 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: ** 111: ** Since [version 3.6.18] ([dateof:3.6.18]), 112: ** SQLite source code has been stored in the 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 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. 121: ** 122: ** See also: [sqlite3_libversion()], 123: ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124: ** [sqlite_version()] and [sqlite_source_id()]. 125: */ 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" 129: 130: /* 131: ** CAPI3REF: Run-Time Library Version Numbers 132: ** KEYWORDS: sqlite3_version sqlite3_sourceid 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 139: ** the header, and thus ensure that the application is 140: ** compiled with matching library and header files. 141: ** 142: ** <blockquote><pre> 143: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144: ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 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 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].)^ 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: ** 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(). 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, 178: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179: ** prefix is omitted from any strings returned by 180: ** sqlite3_compileoption_get(). 181: ** 182: ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183: ** and sqlite3_compileoption_get() may be omitted by specifying the 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); 192: #else 193: # define sqlite3_compileoption_used(X) 0 194: # define sqlite3_compileoption_get(X) ((void*)0) 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 207: ** [SQLITE_THREADSAFE] macro is 0, 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], 225: ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 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()] 243: ** and [sqlite3_close_v2()] are its destructors. There are many other 244: ** interfaces (such as 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 264: ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265: ** between 0 and +18446744073709551615 inclusive. 266: */ 267: #ifdef SQLITE_INT64_TYPE 268: typedef SQLITE_INT64_TYPE sqlite_int64; 269: # ifdef SQLITE_UINT64_TYPE 270: typedef SQLITE_UINT64_TYPE sqlite_uint64; 271: # else 272: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273: # endif 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 294: ** DESTRUCTOR: sqlite3 295: ** 296: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297: ** for the [sqlite3] object. 298: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299: ** the [sqlite3] object is successfully destroyed and all associated 300: ** resources are deallocated. 301: ** 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. 306: ** ^If the database connection is associated with unfinalized prepared 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. 318: ** 319: ** ^If an [sqlite3] object is destroyed while a transaction is open, 320: ** the transaction is automatically rolled back. 321: ** 322: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323: ** must be either a NULL 324: ** pointer or an [sqlite3] object pointer obtained 325: ** from [sqlite3_open()], [sqlite3_open16()], or 326: ** [sqlite3_open_v2()], and not previously closed. 327: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328: ** argument is a harmless no-op. 329: */ 330: SQLITE_API int sqlite3_close(sqlite3*); 331: SQLITE_API int sqlite3_close_v2(sqlite3*); 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 342: ** METHOD: sqlite3 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 347: ** without having to use a lot of C code. 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 367: ** sqlite3_exec() after the error message string is no longer needed. 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 387: ** to an empty string, or a pointer that contains only whitespace and/or 388: ** SQL comments, then no SQL statements are evaluated and the database 389: ** is not changed. 390: ** 391: ** Restrictions: 392: ** 393: ** <ul> 394: ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395: ** is a valid and open [database connection]. 396: ** <li> The application must not close the [database connection] specified by 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 412: ** KEYWORDS: {result code definitions} 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: ** 419: ** See also: [extended result code definitions] 420: */ 421: #define SQLITE_OK 0 /* Successful result */ 422: /* beginning-of-error-codes */ 423: #define SQLITE_ERROR 1 /* Generic error */ 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 */ 438: #define SQLITE_EMPTY 16 /* Internal use only */ 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 */ 446: #define SQLITE_FORMAT 24 /* Not used */ 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 */ 449: #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450: #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 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 457: ** KEYWORDS: {extended result code definitions} 458: ** 459: ** In its default configuration, SQLite API routines return one of 30 integer 460: ** [result codes]. However, experience has shown that many of 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 463: ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464: ** and later) include 465: ** support for additional result codes that provide more detailed information 466: ** about errors. These [extended result codes] are enabled or disabled 467: ** on a per database connection basis using the 468: ** [sqlite3_extended_result_codes()] API. Or, the extended code for 469: ** the most recent error can be obtained using 470: ** [sqlite3_extended_errcode()]. 471: */ 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)) 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)) 497: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 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)) 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)) 507: #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 508: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 509: #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 510: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 511: #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 512: #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 513: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 514: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 515: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 516: #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 517: #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 518: #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 519: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520: #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521: #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 522: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524: #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525: #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526: #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527: #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 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)) 539: #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 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)) 545: #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 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() */ 561: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 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 */ 568: #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 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 */ 574: #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575: 576: /* Reserved: 0x00F00000 */ 577: /* Legacy compatibility: */ 578: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 579: 580: 581: /* 582: ** CAPI3REF: Device Characteristics 583: ** 584: ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 585: ** object returns an integer which is a vector of these 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 603: ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 604: ** flag indicates that a file cannot be deleted when open. The 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. 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]. 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 627: #define SQLITE_IOCAP_IMMUTABLE 0x00002000 628: #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 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: ** 676: ** An [sqlite3_file] object represents an open file in the 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: ** 698: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 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. 735: ** A [file control opcodes | list of opcodes] less than 100 is available. 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] 760: ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 761: ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 762: ** <li> [SQLITE_IOCAP_IMMUTABLE] 763: ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 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 */ 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 */ 807: /* Additional methods may be added in future releases */ 808: }; 809: 810: /* 811: ** CAPI3REF: Standard File Control Opcodes 812: ** KEYWORDS: {file control opcodes} {file control opcode} 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: ** 818: ** <ul> 819: ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 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 825: ** is used during testing and is only available when the SQLITE_TEST 826: ** compile-time option is used. 827: ** 828: ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 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: ** 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: ** 845: ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 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 848: ** by the user. The fourth argument to [sqlite3_file_control()] should 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: ** 854: ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 855: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 856: ** to the [sqlite3_file] object associated with a particular database 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]. 864: ** 865: ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 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 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 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 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. 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 887: ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 888: ** operation of the specialized VFSes that do require it. 889: ** 890: ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 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 901: ** integers where the first integer is the new retry count and the second 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: ** 907: ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 908: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 909: ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 910: ** write ahead log ([WAL file]) and shared memory 911: ** files used for transaction control 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: ** 923: ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 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: ** 933: ** <li>[[SQLITE_FCNTL_OVERWRITE]] 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 936: ** reason, the entire database file will be overwritten by the current 937: ** transaction. This is used by VACUUM operations. 938: ** 939: ** <li>[[SQLITE_FCNTL_VFSNAME]] 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 942: ** final bottom-level VFS are written into memory obtained from 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. 950: ** 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: ** 960: ** <li>[[SQLITE_FCNTL_PRAGMA]] 961: ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 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 972: ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 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 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 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]] 986: ** ^The [SQLITE_FCNTL_BUSYHANDLER] 987: ** file-control may be invoked by SQLite on the database file handle 988: ** shortly after it is opened in order to provide a custom VFS with access 989: ** to the connection's busy-handler callback. The argument is of type (void**) 990: ** - an array of two (void *) values. The first (void *) actually points 991: ** to a function of type (int (*)(void *)). In order to invoke the connection's 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]] 998: ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 999: ** to have SQLite generate a 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: ** 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 1012: ** the value originally pointed to is negative, and so the current limit 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: ** 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: ** 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 not 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 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. 1130: ** </ul> 1131: */ 1132: #define SQLITE_FCNTL_LOCKSTATE 1 1133: #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1134: #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1135: #define SQLITE_FCNTL_LAST_ERRNO 4 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 1145: #define SQLITE_FCNTL_PRAGMA 14 1146: #define SQLITE_FCNTL_BUSYHANDLER 15 1147: #define SQLITE_FCNTL_TEMPFILENAME 16 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 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 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: 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: /* 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: /* 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: ** 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. 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 1253: ** must invent its own temporary name for the file. ^Whenever the 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 1260: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 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] 1274: ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 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() 1302: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 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. 1305: ** It is not used to indicate the file should be opened 1306: ** for exclusive access. 1307: ** 1308: ** ^At least szOsFile bytes of memory are allocated by SQLite 1309: ** to hold the [sqlite3_file] structure passed as the third 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] 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. 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 1349: ** Day Number multiplied by 86400000 (the number of milliseconds in 1350: ** a 24-hour day). 1351: ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1352: ** date and time if that method is available (if iVersion is 2 or 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 1358: ** by some VFSes to facilitate testing of the VFS code. By overriding 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. 1404: ** New fields may be appended in future versions. The iVersion 1405: ** value will increment whenever this happens. 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 1449: ** was given on the corresponding lock. 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: ** 1560: ** 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. 1563: ** 1564: ** The sqlite3_config() interface 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 1586: ** METHOD: sqlite3 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 1594: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 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 1612: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 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()] 1642: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1643: ** that causes the corresponding memory allocation to fail. 1644: ** 1645: ** The xInit method initializes the memory allocator. For example, 1646: ** it might allocate any required mutexes or initialize internal data 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: ** 1652: ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 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 1700: ** value of Single-thread and so [sqlite3_config()] will return 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> 1735: ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1736: ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1737: ** The argument specifies 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> 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] 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: ** 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: ** 1762: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 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: 1767: ** <ul> 1768: ** <li> [sqlite3_hard_heap_limit64()] 1769: ** <li> [sqlite3_memory_used()] 1770: ** <li> [sqlite3_memory_highwater()] 1771: ** <li> [sqlite3_soft_heap_limit64()] 1772: ** <li> [sqlite3_status64()] 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> 1780: ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1781: ** </dd> 1782: ** 1783: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 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 1786: ** cache implementation. 1787: ** This configuration option is a no-op if an application-defined page 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). 1792: ** The sz argument should be the size of the largest database page 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> 1812: ** 1813: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1814: ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1815: ** that SQLite will use for all of its dynamic memory allocation needs 1816: ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 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, 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 1826: ** memory pointer is not NULL then the alternative memory 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> 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 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> 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 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> 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 1862: ** size of each lookaside buffer slot and the second is the number of 1863: ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1864: ** sets the default lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1865: ** option to [sqlite3_db_config()] can be used to change the lookaside 1866: ** configuration on individual connections.)^ </dd> 1867: ** 1868: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1869: ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 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> 1873: ** 1874: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 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> 1878: ** 1879: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 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 1883: ** function with a call signature of void(*)(void*,int,const char*), 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 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 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 1907: ** connection is opened. ^If it is globally disabled, filenames are 1908: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1909: ** database connection is opened. ^(By default, URI handling is globally 1910: ** disabled. The default value may be changed by compiling with the 1911: ** [SQLITE_USE_URI] symbol defined.)^ 1912: ** 1913: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 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 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 1922: ** when the optimization is enabled. Providing the ability to 1923: ** disable the optimization allows the older, buggy application code to work 1924: ** without change even with newer versions of SQLite. 1925: ** 1926: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1927: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 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. 1930: ** </dd> 1931: ** 1932: ** [[SQLITE_CONFIG_SQLLOG]] 1933: ** <dt>SQLITE_CONFIG_SQLLOG 1934: ** <dd>This option is only available if sqlite is compiled with the 1935: ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 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 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 1992: ** becomes the [statement journal] spill-to-disk threshold. 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. 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. 2029: ** </dl> 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* */ 2036: #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 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* */ 2042: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 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* */ 2050: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2051: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 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 */ 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 */ 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> 2075: ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2076: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2077: ** <dd> ^This option takes three additional arguments that determine the 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 2095: ** memory is in use leaves the configuration unchanged and returns 2096: ** [SQLITE_BUSY].)^</dd> 2097: ** 2098: ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 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: ** 2109: ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 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 2118: ** which case the trigger setting is not reported back. 2119: ** 2120: ** 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> 2125: ** 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 2135: ** which case the view setting is not reported back. 2136: ** 2137: ** 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> 2142: ** 2143: ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2144: ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2145: ** <dd> ^This option is used to enable or disable the 2146: ** [fts3_tokenizer()] function which is part of the 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: ** 2157: ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 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: ** 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: ** 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> 2340: ** </dl> 2341: */ 2342: #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 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* */ 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 */ 2361: 2362: /* 2363: ** CAPI3REF: Enable Or Disable Extended Result Codes 2364: ** METHOD: sqlite3 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 2374: ** METHOD: sqlite3 2375: ** 2376: ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2377: ** has a unique 64-bit signed 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: ** 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.)^ 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: /* 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: /* 2445: ** CAPI3REF: Count The Number Of Rows Modified 2446: ** METHOD: sqlite3 2447: ** 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 2455: ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2456: ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 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 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: 2468: ** 2469: ** <ul> 2470: ** <li> ^(Before entering a trigger program the value returned by 2471: ** sqlite3_changes() function is saved. After the trigger program 2472: ** has finished, the original value is restored.)^ 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() 2478: ** value will be saved and restored after each sub-trigger has run.)^ 2479: ** </ul> 2480: ** 2481: ** ^This means that if the changes() SQL function (or similar) is used 2482: ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2483: ** returns the value as set when the calling statement began executing. 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 2486: ** previous INSERT, UPDATE or DELETE statement within the same trigger. 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. 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> 2499: */ 2500: SQLITE_API int sqlite3_changes(sqlite3*); 2501: 2502: /* 2503: ** CAPI3REF: Total Number Of Rows Modified 2504: ** METHOD: sqlite3 2505: ** 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(). 2511: ** 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 2514: ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2515: ** are not counted. 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]. 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. 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> 2536: */ 2537: SQLITE_API int sqlite3_total_changes(sqlite3*); 2538: 2539: /* 2540: ** CAPI3REF: Interrupt A Long-Running Query 2541: ** METHOD: sqlite3 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 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 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: ** 2597: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 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 2614: ** KEYWORDS: {busy-handler callback} {busy handler} 2615: ** METHOD: sqlite3 2616: ** 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]. 2624: ** 2625: ** ^If the busy callback is NULL, then [SQLITE_BUSY] 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 2632: ** been invoked previously for the same locking event. ^If the 2633: ** busy callback returns 0, then no additional attempts are made to 2634: ** access the database and [SQLITE_BUSY] is returned 2635: ** to the application. 2636: ** ^If the callback returns non-zero, then another attempt 2637: ** is made to access the database and the cycle repeats. 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] 2642: ** to the application instead of invoking the 2643: ** busy handler. 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()] 2660: ** or evaluating [PRAGMA busy_timeout=N] will change the 2661: ** busy handler and thus clear any previously set busy handler. 2662: ** 2663: ** The busy callback should not take any actions which modify the 2664: ** database connection that invoked the busy handler. In other words, 2665: ** the busy handler is not reentrant. Any such actions 2666: ** result in undefined behavior. 2667: ** 2668: ** A busy handler must not close the database connection 2669: ** or [prepared statement] that invoked the busy handler. 2670: */ 2671: SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2672: 2673: /* 2674: ** CAPI3REF: Set A Busy Timeout 2675: ** METHOD: sqlite3 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 2682: ** [SQLITE_BUSY]. 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 2688: ** [database connection] at any given moment. If another busy handler 2689: ** was defined (using [sqlite3_busy_handler()]) prior to calling 2690: ** this routine, that other busy handler is cleared.)^ 2691: ** 2692: ** See also: [PRAGMA busy_timeout] 2693: */ 2694: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2695: 2696: /* 2697: ** CAPI3REF: Convenience Routines For Running Queries 2698: ** METHOD: sqlite3 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 result table 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: ** 2734: ** There are two columns (M==2) and three rows (N==3). Thus the 2735: ** result table has 8 entries. Suppose the result table is stored 2736: ** in an array named azResult. Then azResult holds this content: 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. 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. 2788: ** 2789: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2790: ** results into memory obtained from [sqlite3_malloc64()]. 2791: ** The strings returned by these two routines should be 2792: ** released by [sqlite3_free()]. ^Both routines return a 2793: ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 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: ** 2817: ** See also: [built-in printf()], [printf() SQL function] 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 2829: ** does not include operating-system specific [VFS] implementation. The 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: ** 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: ** 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: ** 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) 2857: ** is a NULL pointer then its behavior is identical to calling 2858: ** sqlite3_malloc(N). 2859: ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2860: ** negative then the behavior is exactly the same as calling 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. 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 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. 2883: ** 2884: ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2885: ** sqlite3_malloc64(), and sqlite3_realloc64() 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); 2900: SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2901: SQLITE_API void *sqlite3_realloc(void*, int); 2902: SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2903: SQLITE_API void sqlite3_free(void*); 2904: SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 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 2938: ** the built-in random() and randomblob() SQL functions. This interface allows 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. 2942: ** ^The P parameter can be a NULL pointer. 2943: ** 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 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 2957: ** METHOD: sqlite3 2958: ** KEYWORDS: {authorizer callback} 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()], 2964: ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2965: ** and [sqlite3_prepare16_v3()]. ^At various 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 2981: ** access is denied. 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 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. 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. 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. 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 3034: ** statement might be re-prepared during [sqlite3_step()] due to a 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: ** 3059: ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3060: ** returned from the [sqlite3_vtab_on_conflict()] interface. 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 */ 3118: #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3119: 3120: /* 3121: ** CAPI3REF: Tracing And Profiling Functions 3122: ** METHOD: sqlite3 3123: ** 3124: ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3125: ** instead of the routines described here. 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: ** 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: ** 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 3148: ** might provide greater resolution on the profiler callback. Invoking 3149: ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3150: ** profile callback. 3151: */ 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*, 3155: void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3156: 3157: /* 3158: ** CAPI3REF: SQL Trace Event Codes 3159: ** KEYWORDS: SQLITE_TRACE 3160: ** 3161: ** These constants identify classes of events that can be monitored 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 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 3182: ** is the unexpanded SQL text of the prepared statement or an SQL comment 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 3198: ** statement generates a single row of result. 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: ** 3225: ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3226: ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3227: ** 3228: ** ^The X callback is invoked whenever any of the events identified by 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: /* 3251: ** CAPI3REF: Query Progress Callbacks 3252: ** METHOD: sqlite3 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: ** 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 3262: ** [virtual machine instructions] that are evaluated between successive 3263: ** invocations of the callback X. ^If N is less than one then the progress 3264: ** handler is disabled. 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 3286: ** CONSTRUCTOR: sqlite3 3287: ** 3288: ** ^These routines open an SQLite database file as specified by the 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: ** 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. 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 3312: ** sqlite3_open_v2() must include, at a minimum, one of the following 3313: ** three flag combinations:)^ 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: ** 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: ** 3371: ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3372: ** required combinations shown above optionally combined with other 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 3398: ** set in the third argument to sqlite3_open_v2(), or if it has 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. 3401: ** URI filename interpretation is turned off 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 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 3410: ** present, is ignored. 3411: ** 3412: ** ^SQLite uses the path component of the URI as the name of the disk file 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 3415: ** with a '/' (meaning that the authority section is omitted from the URI) 3416: ** then the path is interpreted as a relative path. 3417: ** ^(On windows, the first component of an absolute path 3418: ** is a drive specification (e.g. "C:").)^ 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]. 3423: ** SQLite and its built-in [VFSes] interpret the 3424: ** following query parameters: 3425: ** 3426: ** <ul> 3427: ** <li> vfs: ^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: ** 3435: ** <li> mode: ^(The mode parameter may be set to either "ro", "rw", 3436: ** "rwc", or "memory". Attempting to set it to any other value is 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 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(). 3449: ** 3450: ** <li> cache: ^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 3453: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3454: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3455: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3456: ** a URI filename, its value overrides any behavior requested by setting 3457: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3458: ** 3459: ** <li> psow: ^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> nolock: ^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> immutable: ^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]. 3479: ** 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 3491: ** <tr><td> file:data.db <td> 3492: ** Open the file "data.db" in the current directory. 3493: ** <tr><td> file:/home/fred/data.db 3494: ** file:///home/fred/data.db 3495: ** file://localhost/home/fred/data.db <td> 3496: ** Open the database file "/home/fred/data.db". 3497: ** <tr><td> file://darkstar/home/fred/data.db <td> 3498: ** An error. "darkstar" is not a recognized authority. 3499: ** <tr><td style="white-space:nowrap"> 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 3502: ** C:. Note that the %20 escaping in this example is not strictly 3503: ** necessary - space characters can be used literally 3504: ** in URI filenames. 3505: ** <tr><td> file:data.db?mode=ro&cache=private <td> 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. 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. 3512: ** <tr><td> file:data.db?mode=readonly <td> 3513: ** An error. "readonly" is not a valid option for the "mode" parameter. 3514: ** Use "ro" instead: "file:data.db?mode=ro". 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 3519: ** percent sign - "%" - followed by exactly two hexadecimal digits 3520: ** specifying an octet value. ^Before the path or query components of a 3521: ** URI filename are interpreted, they are encoded using UTF-8 and all 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: ** Note to Windows users: 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(). 3531: ** 3532: ** Note to Windows Runtime users: 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] 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: ** 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 3558: ** parameter, and if so obtains the value of that query parameter. 3559: ** 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 3574: ** sqlite3_uri_parameter(F,P) returns the value of the P 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 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 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 3584: ** case or if the value begins with a non-zero number. The 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 3588: ** parameter on F or if the value of P does not match any of the 3589: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 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. 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: ** 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 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. 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); 3622: SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3623: 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 3713: ** corruption or segfaults may occur. The value Y should not be 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*); 3727: 3728: /* 3729: ** CAPI3REF: Error Codes And Messages 3730: ** METHOD: sqlite3 3731: ** 3732: ** ^If the most recent sqlite3_* API call associated with 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() 3737: ** interface is the same except that it always returns the 3738: ** [extended result code] even when extended result codes are 3739: ** disabled. 3740: ** 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: ** 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: ** 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: ** 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*); 3784: SQLITE_API const char *sqlite3_errstr(int); 3785: 3786: /* 3787: ** CAPI3REF: Prepared Statement Object 3788: ** KEYWORDS: {prepared statement} {prepared statements} 3789: ** 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 3794: ** original SQL text is source code. A prepared statement object 3795: ** is the compiled object code. All SQL must be converted into a 3796: ** prepared statement before it can be run. 3797: ** 3798: ** The life-cycle of a prepared statement object usually goes like this: 3799: ** 3800: ** <ol> 3801: ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3802: ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3803: ** interfaces. 3804: ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3805: ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 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 3814: ** METHOD: sqlite3 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. 3824: ** ^(For each limit category SQLITE_LIMIT_NAME there is a 3825: ** [limits | hard upper bound] 3826: ** set at compile-time by a C preprocessor macro called 3827: ** [limits | SQLITE_MAX_NAME]. 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: ** 3832: ** ^Regardless of whether or not the limit was changed, the 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 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>)^ 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>)^ 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>)^ 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 3921: #define SQLITE_LIMIT_WORKER_THREADS 11 3922: 3923: /* 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: /* 3963: ** CAPI3REF: Compiling An SQL Statement 3964: ** KEYWORDS: {SQL statement compiler} 3965: ** METHOD: sqlite3 3966: ** CONSTRUCTOR: sqlite3_stmt 3967: ** 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. 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 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. 3991: ** 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 including 3999: ** the nul-terminator. 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: ** 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 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 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. 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> 4044: ** ^If the specific value bound to a [parameter | host parameter] in the 4045: ** WHERE clause might influence the choice of query plan for a statement, 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 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 4052: ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4053: ** </li> 4054: ** </ol> 4055: ** 4056: ** ^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. 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: ); 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: ); 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: ); 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: ); 4106: 4107: /* 4108: ** CAPI3REF: Retrieving Statement SQL 4109: ** METHOD: sqlite3_stmt 4110: ** 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 4113: ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4114: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 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. 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. 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: ** 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. 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()]. 4144: */ 4145: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4146: SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4147: SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4148: 4149: /* 4150: ** CAPI3REF: Determine If An SQL Statement Writes The Database 4151: ** METHOD: sqlite3_stmt 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 4158: ** [virtual tables] might change the database indirectly as a side effect. 4159: ** ^(For example, if an application defines a function "eval()" that 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 4173: ** rather they control the timing of when other statements modify the 4174: ** database. ^The [ATTACH] and [DETACH] statements also cause 4175: ** sqlite3_stmt_readonly() to return true since, while those statements 4176: ** change the configuration of a database connection, they do not make 4177: ** changes to the content of the database files on disk. 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. 4182: */ 4183: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4184: 4185: /* 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: /* 4198: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4199: ** METHOD: sqlite3_stmt 4200: ** 4201: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4202: ** [prepared statement] S has been stepped at least once using 4203: ** [sqlite3_step(S)] but has neither run to completion (returned 4204: ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4205: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4206: ** interface returns false if S is a NULL pointer. If S is not a 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()] 4211: ** to locate all prepared statements associated with a database 4212: ** connection that are in need of being reset. This can be used, 4213: ** for example, in diagnostic routines to search for prepared 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 4231: ** whether or not it requires a protected sqlite3_value. The 4232: ** [sqlite3_value_dup()] interface can be used to construct a new 4233: ** protected sqlite3_value from an unprotected sqlite3_value. 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) 4240: ** or if SQLite is run in one of reduced mutex modes 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. 4252: ** Unprotected sqlite3_value objects may only be used as arguments 4253: ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4254: ** [sqlite3_value_dup()]. 4255: ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4256: ** interfaces require protected sqlite3_value objects. 4257: */ 4258: typedef struct sqlite3_value sqlite3_value; 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} 4278: ** METHOD: sqlite3_stmt 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()] 4309: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4310: ** 4311: ** ^The third argument is the value to bind to the parameter. 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(). 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. 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 bytes in the value, not the number of characters.)^ 4337: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4338: ** is negative, then the length of the string is 4339: ** the number of bytes up to the first zero terminator. 4340: ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4341: ** the behavior is undefined. 4342: ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4343: ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4344: ** that parameter must be the byte offset 4345: ** where the NUL terminator would occur assuming the string were NUL 4346: ** terminated. If any NUL characters occurs at byte offsets less than 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: ** 4351: ** ^The fifth argument to the BLOB and string binding interfaces 4352: ** is a destructor used to dispose of the BLOB or 4353: ** string after SQLite has finished with it. ^The destructor is called 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. 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: ** 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: ** 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: ** 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: ** 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. 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]. 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*)); 4411: SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4412: void(*)(void*)); 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); 4417: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4418: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4419: SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4420: void(*)(void*), unsigned char encoding); 4421: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4422: SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4423: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4424: SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4425: 4426: /* 4427: ** CAPI3REF: Number Of SQL Parameters 4428: ** METHOD: sqlite3_stmt 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 4449: ** METHOD: sqlite3_stmt 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 4466: ** originally specified as UTF-16 in [sqlite3_prepare16()], 4467: ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 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 4477: ** METHOD: sqlite3_stmt 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 4484: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4485: ** [sqlite3_prepare16_v3()]. 4486: ** 4487: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4488: ** [sqlite3_bind_parameter_count()], and 4489: ** [sqlite3_bind_parameter_name()]. 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 4495: ** METHOD: sqlite3_stmt 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 4505: ** METHOD: sqlite3_stmt 4506: ** 4507: ** ^Return the number of columns in the result set returned by the 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. 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 4521: ** METHOD: sqlite3_stmt 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 4551: ** METHOD: sqlite3_stmt 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 4576: ** NULL. ^These routines might also return NULL if a memory allocation error 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 4600: ** METHOD: sqlite3_stmt 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 4633: ** METHOD: sqlite3_stmt 4634: ** 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 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 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 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 4690: ** sqlite3_step(). Failure to reset the prepared statement using 4691: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4692: ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4693: ** sqlite3_step() began 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: ** Goofy Interface Alert: 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 4707: ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4708: ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4709: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4710: ** then the more specific [error codes] are returned directly 4711: ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4712: */ 4713: SQLITE_API int sqlite3_step(sqlite3_stmt*); 4714: 4715: /* 4716: ** CAPI3REF: Number of columns in a result set 4717: ** METHOD: sqlite3_stmt 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 4722: ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 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} 4771: ** METHOD: sqlite3_stmt 4772: ** 4773: ** Summary: 4774: ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4775: ** <tr><td>sqlite3_column_blob<td>→<td>BLOB result 4776: ** <tr><td>sqlite3_column_double<td>→<td>REAL result 4777: ** <tr><td>sqlite3_column_int<td>→<td>32-bit INTEGER result 4778: ** <tr><td>sqlite3_column_int64<td>→<td>64-bit INTEGER result 4779: ** <tr><td>sqlite3_column_text<td>→<td>UTF-8 TEXT result 4780: ** <tr><td>sqlite3_column_text16<td>→<td>UTF-16 TEXT result 4781: ** <tr><td>sqlite3_column_value<td>→<td>The result as an 4782: ** [sqlite3_value|unprotected sqlite3_value] object. 4783: ** <tr><td> <td> <td>  4784: ** <tr><td>sqlite3_column_bytes<td>→<td>Size of a BLOB 4785: ** or a UTF-8 TEXT result in bytes 4786: ** <tr><td>sqlite3_column_bytes16   4787: ** <td>→  <td>Size of UTF-16 4788: ** TEXT in bytes 4789: ** <tr><td>sqlite3_column_type<td>→<td>Default 4790: ** datatype of the result 4791: ** </table></blockquote> 4792: ** 4793: ** Details: 4794: ** 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: ** 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: ** 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], 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 4832: ** versions of SQLite may change the behavior of sqlite3_column_type() 4833: ** following a type conversion. 4834: ** 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: ** 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: ** 4857: ** ^The values returned by [sqlite3_column_bytes()] and 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: ** 4867: ** Warning: ^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()]. 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()], 4874: ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 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. 4879: ** 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 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 Type <th> Requested 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 4892: ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4893: ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 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 4897: ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4898: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 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 4902: ** <tr><td> TEXT <td> BLOB <td> No change 4903: ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4904: ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 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: ** 4933: ** The safest policy is to invoke these routines 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 4953: ** and BLOBs is freed automatically. Do not pass the pointers returned 4954: ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4955: ** [sqlite3_free()]. 4956: ** 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]. 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); 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); 4986: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4987: 4988: /* 4989: ** CAPI3REF: Destroy A Prepared Statement Object 4990: ** DESTRUCTOR: sqlite3_stmt 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 5018: ** METHOD: sqlite3_stmt 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} 5046: ** METHOD: sqlite3 5047: ** 5048: ** ^These functions (collectively known as "function creation routines") 5049: ** are used to add SQL functions or aggregates or to redefine the behavior 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]. 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 5066: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 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 5080: ** its parameters. The application should set this parameter to 5081: ** [SQLITE_UTF16LE] if the function implementation invokes 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. 5088: ** ^When multiple implementations of the same function are available, SQLite 5089: ** will pick the one that involves the least amount of data conversion. 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. 5098: ** 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: ** 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: ** 5115: ** 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: ** 5119: ** ^The sixth, seventh and eighth parameters passed to the three 5120: ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 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: ** 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(). 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 5156: ** match than a function where the encoding is different. 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: ); 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: ); 5211: 5212: /* 5213: ** CAPI3REF: Text Encodings 5214: ** 5215: ** These constant define integer codes that represent the various 5216: ** text encodings supported by SQLite. 5217: */ 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 */ 5221: #define SQLITE_UTF16 4 /* Use native byte order */ 5222: #define SQLITE_ANY 5 /* Deprecated */ 5223: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5224: 5225: /* 5226: ** CAPI3REF: Function Flags 5227: ** 5228: ** These constants may be ORed together with the 5229: ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5230: ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5231: ** [sqlite3_create_function_v2()]. 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: ** 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: ** 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> 5289: */ 5290: #define SQLITE_DETERMINISTIC 0x000000800 5291: #define SQLITE_DIRECTONLY 0x000080000 5292: #define SQLITE_SUBTYPE 0x000100000 5293: #define SQLITE_INNOCUOUS 0x000200000 5294: 5295: /* 5296: ** CAPI3REF: Deprecated Functions 5297: ** DEPRECATED 5298: ** 5299: ** These functions are [deprecated]. In order to maintain 5300: ** backwards compatibility with older code, these functions continue 5301: ** to be supported. However, new applications should avoid 5302: ** the use of these functions. To encourage programmers to avoid 5303: ** these functions, we will not explain what they do. 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); 5311: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5312: void*,sqlite3_int64); 5313: #endif 5314: 5315: /* 5316: ** CAPI3REF: Obtaining SQL Values 5317: ** METHOD: sqlite3_value 5318: ** 5319: ** Summary: 5320: ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5321: ** <tr><td>sqlite3_value_blob<td>→<td>BLOB value 5322: ** <tr><td>sqlite3_value_double<td>→<td>REAL value 5323: ** <tr><td>sqlite3_value_int<td>→<td>32-bit INTEGER value 5324: ** <tr><td>sqlite3_value_int64<td>→<td>64-bit INTEGER value 5325: ** <tr><td>sqlite3_value_pointer<td>→<td>Pointer value 5326: ** <tr><td>sqlite3_value_text<td>→<td>UTF-8 TEXT value 5327: ** <tr><td>sqlite3_value_text16<td>→<td>UTF-16 TEXT value in 5328: ** the native byteorder 5329: ** <tr><td>sqlite3_value_text16be<td>→<td>UTF-16be TEXT value 5330: ** <tr><td>sqlite3_value_text16le<td>→<td>UTF-16le TEXT value 5331: ** <tr><td> <td> <td>  5332: ** <tr><td>sqlite3_value_bytes<td>→<td>Size of a BLOB 5333: ** or a UTF-8 TEXT in bytes 5334: ** <tr><td>sqlite3_value_bytes16   5335: ** <td>→  <td>Size of UTF-16 5336: ** TEXT in bytes 5337: ** <tr><td>sqlite3_value_type<td>→<td>Default 5338: ** datatype of the value 5339: ** <tr><td>sqlite3_value_numeric_type   5340: ** <td>→  <td>Best numeric datatype of the value 5341: ** <tr><td>sqlite3_value_nochange   5342: ** <td>→  <td>True if the column is unchanged in an UPDATE 5343: ** against a virtual table. 5344: ** <tr><td>sqlite3_value_frombind   5345: ** <td>→  <td>True if value originated from a [bound parameter] 5346: ** </table></blockquote> 5347: ** 5348: ** Details: 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]. 5354: ** 5355: ** These routines work only with [protected sqlite3_value] objects. 5356: ** Any attempt to use these routines on an [unprotected sqlite3_value] 5357: ** is not threadsafe. 5358: ** 5359: ** ^These routines work just like the corresponding [column access functions] 5360: ** except that these routines take a single [protected sqlite3_value] object 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: ** 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: ** 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: ** 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: ** 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. 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]. 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*); 5447: SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 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*); 5452: SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5453: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5454: SQLITE_API int sqlite3_value_type(sqlite3_value*); 5455: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5456: SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5457: SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5458: 5459: /* 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: /* 5489: ** CAPI3REF: Obtain Aggregate Function Context 5490: ** METHOD: sqlite3_context 5491: ** 5492: ** Implementations of aggregate SQL functions use this 5493: ** routine to allocate memory for storing their state. 5494: ** 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 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: ** 5508: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5509: ** when first called if N is less than or equal to zero or if a memory 5510: ** allocate error occurs. 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 5514: ** value of N in any subsequent call to sqlite3_aggregate_context() within 5515: ** the same aggregate function instance will not resize the memory 5516: ** allocation.)^ Within the xFinal callback, it is customary to set 5517: ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5518: ** pointless memory allocations occur. 5519: ** 5520: ** ^SQLite automatically frees the memory allocated by 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 5535: ** METHOD: sqlite3_context 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 5550: ** METHOD: sqlite3_context 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 5562: ** METHOD: sqlite3_context 5563: ** 5564: ** These functions may be used by (non-aggregate) SQL functions to 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 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 5570: ** metadata associated with the pattern string. 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. 5574: ** 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 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 5596: ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5597: ** allocation error occurs.)^ </ul> 5598: ** 5599: ** Note the last bullet in particular. The destructor X in 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. 5605: ** 5606: ** ^(In practice, metadata is preserved between function calls for 5607: ** function parameters that are compile-time constants, including literal 5608: ** values and [parameters] and expressions composed from the same.)^ 5609: ** 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: ** 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 5633: ** C++ compilers. 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 5641: ** METHOD: sqlite3_context 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: ** 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. 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 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() 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: ** 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. 5690: ** 5691: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5692: ** error indicating that a memory allocation failed. 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. 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]. 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 5738: ** then SQLite makes a copy of the result into space obtained 5739: ** from [sqlite3_malloc()] before it returns. 5740: ** 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: ** 5760: ** ^The sqlite3_result_value() interface sets the result of 5761: ** the application-defined function to be a copy of the 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: ** 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: ** 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*)); 5786: SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5787: sqlite3_uint64,void(*)(void*)); 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*)); 5798: SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5799: void(*)(void*), unsigned char encoding); 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*); 5804: SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5805: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 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 5814: ** the result from the [application-defined SQL function] with 5815: ** [sqlite3_context] C to be the value T. Only the lower 8 bits 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); 5822: 5823: /* 5824: ** CAPI3REF: Define New Collating Sequences 5825: ** METHOD: sqlite3 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 5845: ** to the collating function callback, xCompare. 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: ** 5854: ** ^The fifth argument, xCompare, is a pointer to the collating function. 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. 5858: ** ^If the xCompare argument is NULL then the collating function is 5859: ** deleted. ^When all collating functions having the same name are deleted, 5860: ** that collation is no longer usable. 5861: ** 5862: ** ^The collating function callback is invoked with a copy of the pArg 5863: ** application data pointer and with two strings in the encoding specified 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 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 AA. 5879: ** <li> If A 5881: ** 5882: ** If a collating function fails any of the above constraints and that 5883: ** collating function is registered and used, then the behavior of SQLite 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: ** 5893: ** ^The xDestroy callback is not called if the 5894: ** sqlite3_create_collation_v2() function fails. Applications that invoke 5895: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5896: ** check the return code and dispose of the application data pointer 5897: ** themselves rather than expecting SQLite to deal with it for them. 5898: ** This is different from every other SQLite interface. The inconsistency 5899: ** is unfortunate but cannot be changed without breaking backwards 5900: ** compatibility. 5901: ** 5902: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5903: */ 5904: SQLITE_API int sqlite3_create_collation( 5905: sqlite3*, 5906: const char *zName, 5907: int eTextRep, 5908: void *pArg, 5909: int(*xCompare)(void*,int,const void*,int,const void*) 5910: ); 5911: SQLITE_API int sqlite3_create_collation_v2( 5912: sqlite3*, 5913: const char *zName, 5914: int eTextRep, 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( 5920: sqlite3*, 5921: const void *zName, 5922: int eTextRep, 5923: void *pArg, 5924: int(*xCompare)(void*,int,const void*,int,const void*) 5925: ); 5926: 5927: /* 5928: ** CAPI3REF: Collation Needed Callbacks 5929: ** METHOD: sqlite3 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( 5955: sqlite3*, 5956: void*, 5957: void(*)(void*,sqlite3*,int eTextRep,const char*) 5958: ); 5959: SQLITE_API int sqlite3_collation_needed16( 5960: sqlite3*, 5961: void*, 5962: void(*)(void*,sqlite3*,int eTextRep,const void*) 5963: ); 5964: 5965: #ifdef SQLITE_ENABLE_CEROD 5966: /* 5967: ** Specify the activation key for a CEROD database. Unless 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: ** 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: ** 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 6023: ** that this variable points to is held in memory obtained from 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. 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. 6034: ** 6035: ** Note to Windows Runtime users: 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> 6049: */ 6050: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6051: 6052: /* 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 6080: ** that this variable points to is held in memory obtained from 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: /* 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: /* 6125: ** CAPI3REF: Test For Auto-Commit Mode 6126: ** KEYWORDS: {autocommit mode} 6127: ** METHOD: sqlite3 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 6150: ** METHOD: sqlite3_stmt 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 6163: ** METHOD: sqlite3 6164: ** 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 6168: ** connection D, or if database N is a temporary or in-memory database, then 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. 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. 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> 6190: */ 6191: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6192: 6193: /* 6194: ** CAPI3REF: Determine if a database is read-only 6195: ** METHOD: sqlite3 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: /* 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: /* 6255: ** CAPI3REF: Find the next prepared statement 6256: ** METHOD: sqlite3 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 6272: ** METHOD: sqlite3 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 6322: ** METHOD: sqlite3 6323: ** 6324: ** ^The sqlite3_update_hook() interface registers a callback function 6325: ** with the [database connection] identified by the first argument 6326: ** to be invoked whenever a row is updated, inserted or deleted in 6327: ** a [rowid table]. 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 6332: ** row is updated, inserted or deleted in a rowid table. 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 6344: ** modified (i.e. sqlite_sequence).)^ 6345: ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6346: ** 6347: ** ^In the current implementation, the update hook 6348: ** is not invoked when conflicting rows are deleted because of an 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: ** 6366: ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6367: ** and [sqlite3_preupdate_hook()] interfaces. 6368: */ 6369: SQLITE_API void *sqlite3_update_hook( 6370: sqlite3*, 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. 6384: ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6385: ** In prior versions of SQLite, 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()]. 6390: ** Existing database connections continue to use the sharing mode 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: ** 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. 6403: ** 6404: ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6405: ** and will always return SQLITE_MISUSE. On those systems, 6406: ** shared cache mode should be enabled per-database connection via 6407: ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6408: ** 6409: ** This interface is threadsafe on processors where writing a 6410: ** 32-bit integer is atomic. 6411: ** 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 6434: ** METHOD: sqlite3 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 6438: ** [sqlite3_release_memory()] interface, this interface is in effect even 6439: ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 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: ** 6449: ** These interfaces impose limits on the amount of heap memory that will be 6450: ** by all database connections within a single process. 6451: ** 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 6459: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6460: ** is advisory only. 6461: ** 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 6471: ** error. ^If the argument N is negative 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. 6488: ** 6489: ** The memory allocation limits can also be adjusted using 6490: ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6491: ** 6492: ** ^(The heap limits are not enforced in the current implementation 6493: ** if one or more of following conditions are true: 6494: ** 6495: ** <ul> 6496: ** <li> The limit value is set to zero. 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: ** 6507: ** The circumstances under which SQLite will enforce the heap limits may 6508: ** changes in future releases of SQLite. 6509: */ 6510: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6511: SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 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 6527: ** METHOD: sqlite3 6528: ** 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 6535: ** SQLITE_ERROR if the specified column does not exist. 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 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. 6542: ** 6543: ** ^The column is identified by the second, third and fourth parameters to 6544: ** this function. ^(The second parameter is either the name of the database 6545: ** (i.e. "main", "temp", or an attached database) containing the specified 6546: ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 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 6551: ** name of the desired column, respectively. 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 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 6570: ** declaration type and collation sequence is valid until the next 6571: ** call to any SQLite API function. 6572: ** 6573: ** ^If the specified table is actually a view, an [error code] is returned. 6574: ** 6575: ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6576: ** is not a [WITHOUT ROWID] table and an 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 6579: ** [INTEGER PRIMARY KEY] column, then the outputs 6580: ** for the [rowid] are set as follows: 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: ** 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. 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 6608: ** METHOD: sqlite3 6609: ** 6610: ** ^This interface loads an SQLite extension library from the named file. 6611: ** 6612: ** ^The sqlite3_load_extension() interface attempts to load an 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. 6619: ** 6620: ** ^The entry point is zProc. 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".)^ 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 6636: ** [sqlite3_enable_load_extension()] or 6637: ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6638: ** prior to calling this API, 6639: ** otherwise an error will be returned. 6640: ** 6641: ** Security warning: It is recommended that the 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: ** 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 6659: ** METHOD: sqlite3 6660: ** 6661: ** ^So as not to open security holes in older applications that are 6662: ** unprepared to deal with [extension loading], and as a means of disabling 6663: ** [extension loading] while evaluating user-entered SQL, the following API 6664: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6665: ** 6666: ** ^Extension loading is off by default. 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. 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: ** Security warning: It is recommended that extension loading 6677: ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 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. 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 6689: ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 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 6694: ** arguments and expects an integer result as if the signature of the 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: ** 6717: ** See also: [sqlite3_reset_auto_extension()] 6718: ** and [sqlite3_cancel_auto_extension()] 6719: */ 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)] 6728: ** routine returns 1 if initialization routine X was successfully 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)); 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: ** 6763: ** This structure, sometimes called a "virtual table module", 6764: ** defines the implementation of a [virtual table]. 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); 6803: /* The methods above are in version 1 of the sqlite_module object. Those 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); 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*); 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: ** 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 6853: ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6854: ** non-zero. 6855: ** 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 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.)^ 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: ** 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 6880: ** to a linear scan of an SQLite table with N rows. A cost of log(N) 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: ** 6887: ** The xBestIndex method may optionally populate the idxFlags field with a 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 6890: ** assumes that the strategy may visit at most one row. 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 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 6908: ** therefore only be used if [sqlite3_libversion_number()] returns a 6909: ** value greater than or equal to 3008002. Similarly, the idxFlags field 6910: ** was added for [version 3.9.0] ([dateof:3.9.0]). 6911: ** It may therefore only be used if 6912: ** sqlite3_libversion_number() returns a value greater than or equal to 6913: ** 3009000. 6914: */ 6915: struct sqlite3_index_info { 6916: /* Inputs */ 6917: int nConstraint; /* Number of entries in aConstraint */ 6918: struct sqlite3_index_constraint { 6919: int iColumn; /* Column constrained. -1 for ROWID */ 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 */ 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 */ 6945: }; 6946: 6947: /* 6948: ** CAPI3REF: Virtual Table Scan Flags 6949: ** 6950: ** Virtual table implementations are allowed to set the 6951: ** [sqlite3_index_info].idxFlags field to some combination of 6952: ** these bits. 6953: */ 6954: #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6955: 6956: /* 6957: ** CAPI3REF: Virtual Table Constraint Operator Codes 6958: ** 6959: ** These macros define the allowed values for the 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: */ 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 6979: 6980: /* 6981: ** CAPI3REF: Register A Virtual Table Implementation 6982: ** METHOD: sqlite3 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 6990: ** by the first parameter. ^The name of the module is given by the 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. 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()] 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: /* 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: /* 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 */ 7063: int nRef; /* Number of open cursors */ 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 7102: ** METHOD: sqlite3 7103: ** 7104: ** ^(Virtual tables can provide alternative implementations of functions 7105: ** using the [xFindFunction] method of the [virtual table module]. 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 7145: ** METHOD: sqlite3 7146: ** CONSTRUCTOR: sqlite3_blob 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: ** 7156: ** ^(Parameter zDb is not the filename that contains the database, but 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: ** 7162: ** ^If the flags parameter is non-zero, then the BLOB is opened for read 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 7169: ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 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> 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)^, 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)^, 7181: ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7182: ** constraint and the blob is being opened for read/write access)^, 7183: ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7184: ** column zColumn is part of a [child key] definition and the blob is 7185: ** being opened for read/write access)^. 7186: ** </ul> 7187: ** 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. 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 7216: ** and the built-in [zeroblob] SQL function may be used to create a 7217: ** zero-filled blob to read or write using the incremental-blob interface. 7218: ** 7219: ** To avoid a resource leak, every open [BLOB handle] should eventually 7220: ** be released by a call to [sqlite3_blob_close()]. 7221: ** 7222: ** See also: [sqlite3_blob_close()], 7223: ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7224: ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 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 7238: ** METHOD: sqlite3_blob 7239: ** 7240: ** ^This function is used to move an existing [BLOB handle] so that it points 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 7244: ** remain the same. Moving an existing [BLOB handle] to a new row is 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: */ 7259: SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7260: 7261: /* 7262: ** CAPI3REF: Close A BLOB Handle 7263: ** DESTRUCTOR: sqlite3_blob 7264: ** 7265: ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7266: ** unconditionally. Even if this routine returns an error code, the 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 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 7278: ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7279: ** is passed a valid open blob handle, the values returned by the 7280: ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7281: */ 7282: SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7283: 7284: /* 7285: ** CAPI3REF: Return The Size Of An Open BLOB 7286: ** METHOD: sqlite3_blob 7287: ** 7288: ** ^Returns the size in bytes of the BLOB accessible via the 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 7302: ** METHOD: sqlite3_blob 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 7331: ** METHOD: sqlite3_blob 7332: ** 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.)^ 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. 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: ** 7347: ** This function may only modify the contents of the BLOB; it is 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, 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 7353: ** than zero [SQLITE_ERROR] is returned and no data is written. 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 7414: ** is selected automatically at compile-time. The following 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 7421: ** </ul> 7422: ** 7423: ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7424: ** that does no real locking and is appropriate for use in 7425: ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7426: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7427: ** and Windows. 7428: ** 7429: ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 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_ 7435: ** function that calls sqlite3_initialize(). 7436: ** 7437: ** ^The sqlite3_mutex_alloc() routine allocates a new 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: 7442: ** 7443: ** <ul> 7444: ** <li> SQLITE_MUTEX_FAST 7445: ** <li> SQLITE_MUTEX_RECURSIVE 7446: ** <li> SQLITE_MUTEX_STATIC_MAIN 7447: ** <li> SQLITE_MUTEX_STATIC_MEM 7448: ** <li> SQLITE_MUTEX_STATIC_OPEN 7449: ** <li> SQLITE_MUTEX_STATIC_PRNG 7450: ** <li> SQLITE_MUTEX_STATIC_LRU 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> 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 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 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 7473: ** a pointer to a static preexisting mutex. ^Nine static mutexes are 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() 7482: ** returns a different mutex on every call. ^For the static 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 7487: ** allocated dynamic mutex. Attempting to deallocate a static 7488: ** mutex results in undefined behavior. 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. 7496: ** In such cases, the 7497: ** mutex must be exited an equal number of times before another thread 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. 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() 7503: ** will always return SQLITE_BUSY. The SQLite core only ever uses 7504: ** sqlite3_mutex_try() as an optimization so this is acceptable 7505: ** behavior.)^ 7506: ** 7507: ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7508: ** previously entered by the same thread. The behavior 7509: ** is undefined if the mutex is not currently entered by the 7510: ** calling thread or is not currently allocated. 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 7531: ** sufficient, however the application has the option of substituting a custom 7532: ** implementation for specialized deployments or systems for which SQLite 7533: ** does not provide a suitable implementation. In this case, the application 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 7569: ** by this structure are not required to handle this case. The results 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: ** 7574: ** The xMutexInit() method must be threadsafe. It must be harmless to 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: ** 7579: ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7580: ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 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 7606: ** are intended for use inside assert() statements. The SQLite core 7607: ** never uses these routines except inside an assert() and applications 7608: ** are advised to follow the lead of the core. The SQLite core only 7609: ** provides implementations for these routines when it is compiled 7610: ** with the SQLITE_DEBUG flag. External mutex implementations 7611: ** are only required to provide these routines if SQLITE_DEBUG is 7612: ** defined and if NDEBUG is not defined. 7613: ** 7614: ** These routines should return true if the mutex in their argument 7615: ** is held or not held, respectively, by the calling thread. 7616: ** 7617: ** The implementation is not required to provide versions of these 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: ** 7622: ** If the argument to sqlite3_mutex_held() is a NULL pointer then 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 7628: ** the appropriate thing to do. The sqlite3_mutex_notheld() 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 7648: #define SQLITE_MUTEX_STATIC_MAIN 2 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() */ 7652: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 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() */ 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 */ 7662: 7663: /* Legacy compatibility: */ 7664: #define SQLITE_MUTEX_STATIC_MASTER 2 7665: 7666: 7667: /* 7668: ** CAPI3REF: Retrieve the mutex for a database connection 7669: ** METHOD: sqlite3 7670: ** 7671: ** ^This interface returns a pointer the [sqlite3_mutex] object that 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 7681: ** METHOD: sqlite3 7682: ** KEYWORDS: {file control} 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: ** 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 7701: ** a pointer to the underlying [sqlite3_file] object to be written into 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. 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: ** 7718: ** See also: [file control opcodes] 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 7755: #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 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 7762: #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7763: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7764: #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7765: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7766: #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7767: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7768: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7769: #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 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 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 7780: #define SQLITE_TESTCTRL_SEEK_COUNT 30 7781: #define SQLITE_TESTCTRL_TRACEFLAGS 31 7782: #define SQLITE_TESTCTRL_LAST 31 /* Largest TESTCTRL */ 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*); 7966: 7967: /* 7968: ** CAPI3REF: SQLite Runtime Status 7969: ** 7970: ** ^These interfaces are used to retrieve runtime status information 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: ** 7984: ** ^The sqlite3_status() and sqlite3_status64() routines return 7985: ** SQLITE_OK on success and a non-zero [error code] on failure. 7986: ** 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. 7990: ** 7991: ** See also: [sqlite3_db_status()] 7992: */ 7993: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7994: SQLITE_API int sqlite3_status64( 7995: int op, 7996: sqlite3_int64 *pCurrent, 7997: sqlite3_int64 *pHighwater, 7998: int resetFlag 7999: ); 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 8014: ** and internal memory usage by the SQLite library. Auxiliary page-cache 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 8023: ** *pHighwater parameter to [sqlite3_status()] is of interest. 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 8032: ** [pagecache memory allocator] that was configured using 8033: ** [SQLITE_CONFIG_PAGECACHE]. The 8034: ** value returned is in pages, not in bytes.</dd>)^ 8035: ** 8036: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 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 8048: ** handed to the [pagecache memory allocator]. Only the value returned in the 8049: ** *pHighwater parameter to [sqlite3_status()] is of interest. 8050: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8051: ** 8052: ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8053: ** <dd>No longer used.</dd> 8054: ** 8055: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8056: ** <dd>No longer used.</dd> 8057: ** 8058: ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8059: ** <dd>No longer used.</dd> 8060: ** 8061: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8062: ** <dd>The *pHighwater parameter records the deepest parser stack. 8063: ** The *pCurrent value is undefined. The *pHighwater value is only 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 8072: #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8073: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8074: #define SQLITE_STATUS_MALLOC_SIZE 5 8075: #define SQLITE_STATUS_PARSER_STACK 6 8076: #define SQLITE_STATUS_PAGECACHE_SIZE 7 8077: #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8078: #define SQLITE_STATUS_MALLOC_COUNT 9 8079: 8080: /* 8081: ** CAPI3REF: Database Connection Status 8082: ** METHOD: sqlite3 8083: ** 8084: ** ^This interface is used to retrieve runtime status information 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 8089: ** determines the parameter to interrogate. The set of 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> 8124: ** <dd>This parameter returns the number of malloc attempts that were 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> 8145: ** <dd>This parameter returns the approximate number of bytes of heap 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: ** 8149: ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 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: ** 8161: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8162: ** <dd>This parameter returns the approximate number of bytes of heap 8163: ** memory used to store the schema for all databases associated 8164: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 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> 8171: ** <dd>This parameter returns the approximate number of bytes of heap 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 8179: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 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 8185: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8186: ** is always 0. 8187: ** </dd> 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> 8199: ** 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: ** 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> 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 8225: #define SQLITE_DBSTATUS_CACHE_WRITE 9 8226: #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8227: #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8228: #define SQLITE_DBSTATUS_CACHE_SPILL 12 8229: #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8230: 8231: 8232: /* 8233: ** CAPI3REF: Prepared Statement Status 8234: ** METHOD: sqlite3_stmt 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 8243: ** an index. 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 8270: ** may indicate opportunities for performance improvement through 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> 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 8288: ** to 2147483647. The number of virtual machine operations can be 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. 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. 8310: ** </dd> 8311: ** </dl> 8312: */ 8313: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8314: #define SQLITE_STMTSTATUS_SORT 2 8315: #define SQLITE_STMTSTATUS_AUTOINDEX 3 8316: #define SQLITE_STMTSTATUS_VM_STEP 4 8317: #define SQLITE_STMTSTATUS_REPREPARE 5 8318: #define SQLITE_STMTSTATUS_RUN 6 8319: #define SQLITE_STMTSTATUS_MEMUSED 99 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 8355: ** register an alternative page cache implementation by passing in an 8356: ** instance of the sqlite3_pcache_methods2 structure.)^ 8357: ** In many applications, most of the heap memory allocated by 8358: ** SQLite is used for the page cache. 8359: ** By implementing a 8360: ** custom page cache using this API, an application can better control 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 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]] 8376: ** ^(The xInit() method is called once for each effective 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.)^ 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 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()]. 8388: ** It can be used to clean up 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 8407: ** second parameter szExtra is a number of bytes of extra storage 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 8420: ** false will always have the "discard" flag set to true. 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. 8435: ** 8436: ** [[the xFetch() page cache methods]] 8437: ** The xFetch() method locates a page in the cache and returns a pointer to 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 8440: ** pointer to a buffer of szPage bytes used to store the content of a 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> 8456: ** <tr><th> createFlag <th> Behavior when page is not already in cache 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 8466: ** failed.)^ In between the xFetch() calls, SQLite may 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: ** 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 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); 8520: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 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 8565: ** for copying in-memory databases to or from persistent files. 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. 8576: ** 8577: ** ^(To perform a backup operation: 8578: ** <ol> 8579: ** <li>sqlite3_backup_init() is called once to initialize the 8580: ** backup, 8581: ** <li>sqlite3_backup_step() is called one or more times to transfer 8582: ** the data between the two databases, and finally 8583: ** <li>sqlite3_backup_finish() is called to release all resources 8584: ** associated with the backup operation. 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()]] sqlite3_backup_init() 8590: ** 8591: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8592: ** [database connection] associated with the destination database 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. 8597: ** ^The S and M arguments passed to 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: ** 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 8606: ** destination database. 8607: ** 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 8617: ** sqlite3_backup_finish() functions to perform the specified backup 8618: ** operation. 8619: ** 8620: ** [[sqlite3_backup_step()]] sqlite3_backup_step() 8621: ** 8622: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8623: ** the source and destination databases specified by [sqlite3_backup] object B. 8624: ** ^If N is negative, all remaining source pages are copied. 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] 8646: ** is invoked (if one is specified). ^If the 8647: ** busy-handler returns non-zero before the lock is available, then 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 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 8659: ** to the sqlite3_backup_finish() to release associated resources. 8660: ** 8661: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 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 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 8672: ** restarted by the next call to sqlite3_backup_step(). ^If the source 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()]] sqlite3_backup_finish() 8678: ** 8679: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 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 8683: ** resources associated with the [sqlite3_backup] object. 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: ** 8700: ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8701: ** sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8702: ** 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().)^ 8714: ** 8715: ** Concurrent Usage of Database Handles 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: ** 8723: ** However, the application must guarantee that the destination 8724: ** [database connection] is not passed to any other API (by any thread) after 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 8735: ** that the application must guarantee that the disk file being 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: ** 8739: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 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 8759: ** METHOD: sqlite3 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 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 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 8773: ** its current transaction, either by committing it or rolling it back. 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 8778: ** has locked the required resource is stored internally. ^After an 8779: ** application receives an SQLITE_LOCKED error, it may call the 8780: ** sqlite3_unlock_notify() method with the blocked connection handle as 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] 8784: ** call that concludes the blocking connection's transaction. 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 8794: ** a read-lock on the same table, then SQLite arbitrarily selects one of 8795: ** the other connections to use as the blocking connection. 8796: ** 8797: ** ^(There may be at most one unlock-notify callback registered by a 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 8802: ** unlock-notify callback is canceled. ^The blocked connections 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: ** Callback Invocation Details 8814: ** 8815: ** When an unlock-notify callback is registered, the application provides a 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: ** 8822: ** When a blocking connection's transaction is concluded, there may be 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. 8828: ** This gives the application an opportunity to prioritize any actions 8829: ** related to the set of unblocked database connections. 8830: ** 8831: ** Deadlock Detection 8832: ** 8833: ** Assuming that after registering for an unlock-notify callback a 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: ** The "DROP TABLE" Exception 8855: ** 8856: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 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 8869: ** the special "DROP TABLE/INDEX" case, the extended error code is just 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: ** 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. 8886: */ 8887: SQLITE_API int sqlite3_stricmp(const char *, const char *); 8888: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8889: 8890: /* 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: /* 8931: ** CAPI3REF: Error Logging Interface 8932: ** 8933: ** ^The [sqlite3_log()] interface writes a message into the [error log] 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 8955: ** METHOD: sqlite3 8956: ** 8957: ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8958: ** is invoked each time data is committed to a database in wal mode. 8959: ** 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 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: ** 8980: ** A single database handle may have at most a single write-ahead log callback 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 8985: ** overwrite any prior [sqlite3_wal_hook()] settings. 8986: */ 8987: SQLITE_API void *sqlite3_wal_hook( 8988: sqlite3*, 8989: int(*)(void *,sqlite3*,const char*,int), 8990: void* 8991: ); 8992: 8993: /* 8994: ** CAPI3REF: Configure an auto-checkpoint 8995: ** METHOD: sqlite3 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 9001: ** more frames in the [write-ahead log] file. ^Passing zero or 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: ** 9013: ** ^Checkpoints initiated by this mechanism are 9014: ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9015: ** 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 9026: ** METHOD: sqlite3 9027: ** 9028: ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9029: ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9030: ** 9031: ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 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()]. 9043: */ 9044: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9045: 9046: /* 9047: ** CAPI3REF: Checkpoint a database 9048: ** METHOD: sqlite3 9049: ** 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]:)^ 9054: ** 9055: ** <dl> 9056: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 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 9059: ** in the log were checkpointed. ^The [busy-handler callback] 9060: ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9061: ** ^On the other hand, passive mode might leave the checkpoint unfinished 9062: ** if there are concurrent readers or writers. 9063: ** 9064: ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9065: ** ^This mode blocks (it invokes the 9066: ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9067: ** database writer and all readers are reading from the most recent database 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. 9071: ** 9072: ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9073: ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9074: ** that after checkpointing the log file it blocks (calls the 9075: ** [busy-handler callback]) 9076: ** until all readers are reading from the database file only. ^This ensures 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. 9085: ** </dl> 9086: ** 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. 9096: ** 9097: ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 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 9100: ** busy-handler configured, it will not be invoked in this case. 9101: ** 9102: ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 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 9108: ** the writer lock is obtained or while waiting for database readers, the 9109: ** checkpoint operation proceeds from that point in the same way as 9110: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9111: ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9112: ** 9113: ** ^If parameter zDb is NULL or points to a zero length string, then the 9114: ** specified operation is attempted on all WAL databases [attached] to 9115: ** [database connection] db. In this case the 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 9123: ** databases, SQLITE_OK is returned. 9124: ** 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 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. 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. 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: /* 9147: ** CAPI3REF: Checkpoint Mode Values 9148: ** KEYWORDS: {checkpoint mode} 9149: ** 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 */ 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: ** 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. 9177: */ 9178: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9179: 9180: /* 9181: ** CAPI3REF: Virtual Table Configuration Options 9182: ** KEYWORDS: {virtual table configuration options} 9183: ** KEYWORDS: {virtual table configuration option} 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> 9190: ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9191: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 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. 9205: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9206: ** is able to roll back a statement or database transaction, and abandon 9207: ** or continue processing the current SQL statement as appropriate. 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 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 9216: ** silently replace the appropriate rows within the xUpdate callback and 9217: ** return SQLITE_OK. Or, if this is not possible, it may return 9218: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9219: ** constraint handling. 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> 9240: ** </dl> 9241: */ 9242: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9243: #define SQLITE_VTAB_INNOCUOUS 2 9244: #define SQLITE_VTAB_DIRECTONLY 3 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: /* 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] 9262: ** method of a [virtual table], then it might return true if the 9263: ** column is being fetched as part of an UPDATE operation during which the 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 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. 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. 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: /* 9300: ** CAPI3REF: Conflict resolution modes 9301: ** KEYWORDS: {conflict resolution mode} 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: 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> 9331: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 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> 9335: ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 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> 9339: ** <dd>^The "double" variable pointed to by the V parameter will be set to the 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> 9347: ** <dd>^The "const char *" variable pointed to by the V parameter will be set 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> 9352: ** <dd>^The "const char *" variable pointed to by the V parameter will be set 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> 9357: ** <dd>^The "int" variable pointed to by the V parameter will be set to the 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 */ 9407: ); 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 9422: ** METHOD: sqlite3 9423: ** 9424: ** ^If a write-transaction is open on [database connection] D when the 9425: ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9426: ** pages in the pager-cache that are not currently in use are written out 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: ** 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 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. 9455: ** METHOD: sqlite3 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 9462: ** on a database table. 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: ** 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. 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 9482: ** will be "main" for the main database or "temp" for TEMP tables or 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. 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 9496: ** DELETE operations on rowid tables. 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 9530: ** operation; or 1 for inserts, updates, or deletes invoked by top-level 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: */ 9536: #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9537: SQLITE_API void *sqlite3_preupdate_hook( 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: ); 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 9555: 9556: /* 9557: ** CAPI3REF: Low-level system error code 9558: ** METHOD: sqlite3 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 9565: ** as ENOSPC, EAUTH, EISDIR, and so forth. 9566: */ 9567: SQLITE_API int sqlite3_system_errno(sqlite3*); 9568: 9569: /* 9570: ** CAPI3REF: Database Snapshot 9571: ** KEYWORDS: {snapshot} {sqlite3_snapshot} 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: */ 9589: typedef struct sqlite3_snapshot { 9590: unsigned char hidden[48]; 9591: } sqlite3_snapshot; 9592: 9593: /* 9594: ** CAPI3REF: Record A Database Snapshot 9595: ** CONSTRUCTOR: sqlite3_snapshot 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. 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. 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 9634: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 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 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. 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 9677: ** I/O on that database connection, or if the database entered [WAL mode] 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 9683: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 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 9693: ** DESTRUCTOR: sqlite3_snapshot 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 9700: ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9701: */ 9702: SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9703: 9704: /* 9705: ** CAPI3REF: Compare the ages of two snapshot handles. 9706: ** METHOD: sqlite3_snapshot 9707: ** 9708: ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9709: ** of two valid snapshot handles. 9710: ** 9711: ** If the two snapshot handles are not associated with the same database 9712: ** file, the result of the comparison is undefined. 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 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 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. 9725: ** 9726: ** This interface is only available if SQLite is compiled with the 9727: ** [SQLITE_ENABLE_SNAPSHOT] option. 9728: */ 9729: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9730: sqlite3_snapshot *p1, 9731: sqlite3_snapshot *p2 9732: ); 9733: 9734: /* 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: /* 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 9892: #endif /* SQLITE3_H */ 9893: 9894: /******** Begin file sqlite3rtree.h *********/ 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; 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 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, 9937: int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 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[] */ 9949: sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9950: void *pUser; /* Callback implementation user data */ 9951: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9952: }; 9953: 9954: /* 9955: ** Register a 2nd-generation geometry callback named zScore that can be 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: /* 9970: ** A pointer to a structure of the following type is passed as the 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 */ 9992: int eWithin; /* OUT: Visibility */ 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: 10005: 10006: #ifdef __cplusplus 10007: } /* end of the 'extern "C"' block */ 10008: #endif 10009: 10010: #endif /* ifndef _SQLITE3RTREE_H_ */ 10011: 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 10028: ** 10029: ** An instance of this object is a [session] that can be used to 10030: ** record changes to a database. 10031: */ 10032: typedef struct sqlite3_session sqlite3_session; 10033: 10034: /* 10035: ** CAPI3REF: Changeset Iterator Handle 10036: ** 10037: ** An instance of this object acts as a cursor for iterating 10038: ** over the elements of a [changeset] or [patchset]. 10039: */ 10040: typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10041: 10042: /* 10043: ** CAPI3REF: Create A New Session Object 10044: ** CONSTRUCTOR: sqlite3_session 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 10065: ** which a pre-update hook is already defined. The results of attempting 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: */ 10073: SQLITE_API int sqlite3session_create( 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 10081: ** DESTRUCTOR: sqlite3_session 10082: ** 10083: ** Delete a session object previously allocated using 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 10089: ** are attached is closed. Refer to the documentation for 10090: ** [sqlite3session_create()] for details. 10091: */ 10092: SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10093: 10094: 10095: /* 10096: ** CAPI3REF: Enable Or Disable A Session Object 10097: ** METHOD: sqlite3_session 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 10107: ** greater than zero enables it. Passing a value less than zero is a 10108: ** no-op, and may be used to query the current state of the session. 10109: ** 10110: ** The return value indicates the final state of the session object: 0 if 10111: ** the session is disabled, or 1 if it is enabled. 10112: */ 10113: SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10114: 10115: /* 10116: ** CAPI3REF: Set Or Clear the Indirect Change Flag 10117: ** METHOD: sqlite3_session 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 10125: ** <li> The change is made by an SQL trigger or foreign key action 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 10137: ** of the indirect flag, and may be used to query the current state of the 10138: ** indirect flag for the specified session object. 10139: ** 10140: ** The return value indicates the final state of the indirect flag: 0 if 10141: ** it is clear, or 1 if it is set. 10142: */ 10143: SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10144: 10145: /* 10146: ** CAPI3REF: Attach A Table To A Session Object 10147: ** METHOD: sqlite3_session 10148: ** 10149: ** If argument zTab is not NULL, then it is the name of a table to attach 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 10152: ** documentation for [sqlite3session_changeset()] for further details. 10153: ** 10154: ** Or, if argument zTab is NULL, then changes are recorded for all tables 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 10157: ** the new tables are also recorded. 10158: ** 10159: ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10160: ** defined as part of their CREATE TABLE statement. It does not matter if the 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. 10163: ** 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: ** 10171: ** SQLITE_OK is returned if the call completes without error. Or, if an error 10172: ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 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. 10202: */ 10203: SQLITE_API int sqlite3session_attach( 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. 10210: ** METHOD: sqlite3_session 10211: ** 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 10216: ** attached, xFilter will not be called again. 10217: */ 10218: SQLITE_API void sqlite3session_table_filter( 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 10229: ** METHOD: sqlite3_session 10230: ** 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 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: ** 10248: ** Changes are not recorded for rows that have NULL values stored in one or 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 10301: ** change is added to the changeset. If no such row is found, no change 10302: ** is added to the changeset. 10303: ** 10304: ** <li> For each record generated by an update or delete, the database is 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 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 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 10316: ** will be present in the changeset. Or if a row is deleted and then later a 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 10325: ** is inserted while a session object is enabled, then later deleted while 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. 10328: ** Or, if one field of a row is updated while a session is disabled, and 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: */ 10332: SQLITE_API int sqlite3session_changeset( 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: /* 10339: ** CAPI3REF: Load The Difference Between Tables Into A Session 10340: ** METHOD: sqlite3_session 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.) 10349: ** attached to the same database handle as the session object that contains 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 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 10367: ** object (call this the "to-table"). Specifically: 10368: ** 10369: ** <ul> 10370: ** <li> For each row (primary key) that exists in the to-table but not in 10371: ** the from-table, an INSERT record is added to the session object. 10372: ** 10373: ** <li> For each row (primary key) that exists in the to-table but not in 10374: ** the from-table, a DELETE record is added to the session object. 10375: ** 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. 10379: ** </ul> 10380: ** 10381: ** To clarify, if this function is called and then a changeset constructed 10382: ** using [sqlite3session_changeset()], then after applying that changeset to 10383: ** database zFrom the contents of the two compatible tables would be 10384: ** identical. 10385: ** 10386: ** It an error if database zFrom does not exist or does not contain the 10387: ** required compatible table. 10388: ** 10389: ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10390: ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10391: ** may be set to point to a buffer containing an English language error 10392: ** message. It is the responsibility of the caller to free this buffer using 10393: ** sqlite3_free(). 10394: */ 10395: SQLITE_API int sqlite3session_diff( 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 10405: ** METHOD: sqlite3_session 10406: ** 10407: ** The differences between a patchset and a changeset are that: 10408: ** 10409: ** <ul> 10410: ** <li> DELETE records consist of the primary key fields only. The 10411: ** original values of other fields are omitted. 10412: ** <li> The original values of any modified fields are omitted from 10413: ** UPDATE records. 10414: ** </ul> 10415: ** 10416: ** A patchset blob may be used with up to date versions of all 10417: ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10418: ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10419: ** attempting to use a patchset blob with old versions of the 10420: ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10421: ** 10422: ** Because the non-primary key "old.*" fields are omitted, no 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: */ 10432: SQLITE_API int sqlite3session_patchset( 10433: sqlite3_session *pSession, /* Session object */ 10434: int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10435: void **ppPatchset /* OUT: Buffer containing patchset */ 10436: ); 10437: 10438: /* 10439: ** CAPI3REF: Test if a changeset has recorded any changes. 10440: ** 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 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 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 10449: ** are restored. However, if this function returns non-zero, then it is 10450: ** guaranteed that a call to sqlite3session_changeset() will return a 10451: ** changeset containing zero changes. 10452: */ 10453: SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10454: 10455: /* 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: /* 10464: ** CAPI3REF: Create An Iterator To Traverse A Changeset 10465: ** CONSTRUCTOR: sqlite3_changeset_iter 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: ** 10472: ** The following functions can be used to advance and query a changeset 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 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 10495: ** another change for table X. 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 experimental 10502: ** and therefore subject to change. 10503: */ 10504: SQLITE_API int sqlite3changeset_start( 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: ); 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 10528: 10529: 10530: /* 10531: ** CAPI3REF: Advance A Changeset Iterator 10532: ** METHOD: sqlite3_changeset_iter 10533: ** 10534: ** This function may only be used with iterators created by the function 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 10545: ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10546: ** Otherwise, if all changes in the changeset have already been visited, 10547: ** SQLITE_DONE is returned. 10548: ** 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 10551: ** SQLITE_NOMEM. 10552: */ 10553: SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10554: 10555: /* 10556: ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10557: ** METHOD: sqlite3_changeset_iter 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: ** 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 10579: ** is an indirect change, or false (0) otherwise. See the documentation for 10580: ** [sqlite3session_indirect()] for a description of direct and indirect 10581: ** changes. 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: */ 10587: SQLITE_API int sqlite3changeset_op( 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 10597: ** METHOD: sqlite3_changeset_iter 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: ** 10613: ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 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: */ 10621: SQLITE_API int sqlite3changeset_pk( 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 10629: ** METHOD: sqlite3_changeset_iter 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 10634: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 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 10644: ** sqlite3_value object containing the iVal'th value from the vector of 10645: ** original row values stored as part of the UPDATE or DELETE change and 10646: ** returns SQLITE_OK. The name of the function comes from the fact that this 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: */ 10652: SQLITE_API int sqlite3changeset_old( 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 10660: ** METHOD: sqlite3_changeset_iter 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 10665: ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 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 10675: ** sqlite3_value object containing the iVal'th value from the vector of 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 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 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: */ 10686: SQLITE_API int sqlite3changeset_new( 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 10694: ** METHOD: sqlite3_changeset_iter 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 10707: ** sqlite3_value object containing the iVal'th value from the 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: */ 10714: SQLITE_API int sqlite3changeset_conflict( 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 10722: ** METHOD: sqlite3_changeset_iter 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: */ 10731: SQLITE_API int sqlite3changeset_fk_conflicts( 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 10739: ** METHOD: sqlite3_changeset_iter 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() 10751: ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 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: ** 10756: ** <pre> 10757: ** sqlite3changeset_start(); 10758: ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10759: ** // Do something with change. 10760: ** } 10761: ** rc = sqlite3changeset_finalize(); 10762: ** if( rc!=SQLITE_OK ){ 10763: ** // An error has occurred 10764: ** } 10765: ** </pre> 10766: */ 10767: SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 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() 10791: ** on the *ppOut pointer to free the buffer allocation following a successful 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: */ 10797: SQLITE_API int sqlite3changeset_invert( 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: ** 10805: ** This function is used to concatenate two changesets, A and B, into a 10806: ** single changeset. The result is a changeset equivalent to applying 10807: ** changeset A followed by changeset B. 10808: ** 10809: ** This function combines the two input changesets using an 10810: ** sqlite3_changegroup object. Calling it produces similar results as the 10811: ** following code fragment: 10812: ** 10813: ** <pre> 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: ** } 10824: ** </pre> 10825: ** 10826: ** Refer to the sqlite3_changegroup documentation below for details. 10827: */ 10828: SQLITE_API int sqlite3changeset_concat( 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: /* 10839: ** CAPI3REF: Changegroup Handle 10840: ** 10841: ** A changegroup is an object used to combine two or more 10842: ** [changesets] or [patchsets] 10843: */ 10844: typedef struct sqlite3_changegroup sqlite3_changegroup; 10845: 10846: /* 10847: ** CAPI3REF: Create A New Changegroup Object 10848: ** CONSTRUCTOR: sqlite3_changegroup 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 10857: ** should eventually free the returned object using a call to 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: ** 10869: ** <li> The result of combining all input changesets together is obtained 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: ** 10878: ** As well as the regular sqlite3changegroup_add() and 10879: ** sqlite3changegroup_output() functions, also available are the streaming 10880: ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10881: */ 10882: SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10883: 10884: /* 10885: ** CAPI3REF: Add A Changeset To A Changegroup 10886: ** METHOD: sqlite3_changegroup 10887: ** 10888: ** Add all changes within the changeset (or patchset) in buffer pData (size 10889: ** nData bytes) to the changegroup. 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: ** 10902: ** Changes to rows that do not already appear in the changegroup are 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> 10916: ** The INSERT change remains in the changegroup. The values in the 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> 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 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 10935: ** new change differ from those in the row deleted by the existing 10936: ** change, the existing DELETE is replaced by an UPDATE within the 10937: ** changegroup. Otherwise, if the inserted row is exactly the same 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 10955: ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10956: ** of the final contents of the changegroup is undefined. 10957: ** 10958: ** If no error occurs, SQLITE_OK is returned. 10959: */ 10960: SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10961: 10962: /* 10963: ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10964: ** METHOD: sqlite3_changegroup 10965: ** 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 10982: ** is returned and the output variables are set to the size of and a 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: */ 10987: SQLITE_API int sqlite3changegroup_output( 10988: sqlite3_changegroup*, 10989: int *pnData, /* OUT: Size of output buffer in bytes */ 10990: void **ppData /* OUT: Pointer to output buffer */ 10991: ); 10992: 10993: /* 10994: ** CAPI3REF: Delete A Changegroup Object 10995: ** DESTRUCTOR: sqlite3_changegroup 10996: */ 10997: SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10998: 10999: /* 11000: ** CAPI3REF: Apply A Changeset To A Database 11001: ** 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. 11005: ** 11006: ** The fourth argument (xFilter) passed to these functions is the "filter 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 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. 11014: ** 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 11017: ** considered compatible if all of the following are true: 11018: ** 11019: ** <ul> 11020: ** <li> The table has the same name as the name recorded in the 11021: ** changeset, and 11022: ** <li> The table has at least as many columns as recorded in the 11023: ** changeset, and 11024: ** <li> The table has primary key columns in the same position as 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: ** 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 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 11045: ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 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 11050: ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11051: ** actions are taken by sqlite3changeset_apply() depending on the value 11052: ** returned by each invocation of the conflict-handler function. Refer to 11053: ** the documentation for the three 11054: ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11055: ** 11056: ** <dl> 11057: ** <dt>DELETE Changes<dd> 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 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 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. 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 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. 11089: ** 11090: ** If the attempt to insert the row fails because the database already 11091: ** contains a row with the same primary key values, the conflict handler 11092: ** function is invoked with the second argument set to 11093: ** [SQLITE_CHANGESET_CONFLICT]. 11094: ** 11095: ** If the attempt to insert the row fails because of some other constraint 11096: ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11097: ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11098: ** This includes the case where the INSERT operation is re-attempted because 11099: ** an earlier call to the conflict handler function returned 11100: ** [SQLITE_CHANGESET_REPLACE]. 11101: ** 11102: ** <dt>UPDATE Changes<dd> 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. 11108: ** 11109: ** If a row with matching primary key values is found, but one or more of 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 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: ** 11121: ** If the UPDATE operation is attempted, but SQLite returns 11122: ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11123: ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11124: ** This includes the case where the UPDATE operation is attempted after 11125: ** an earlier call to the conflict handler function returned 11126: ** [SQLITE_CHANGESET_REPLACE]. 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. 11131: ** This can be used to further customize the application's conflict 11132: ** resolution strategy. 11133: ** 11134: ** All changes made by these functions are enclosed in a savepoint transaction. 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 11137: ** rolled back, restoring the target database to its original state, and an 11138: ** SQLite error code returned. 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 experimental 11155: ** and therefore subject to change. 11156: */ 11157: SQLITE_API int sqlite3changeset_apply( 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: ); 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: ); 11189: 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: /* 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 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 11225: ** expected "before" values. 11226: ** 11227: ** The conflicting row, in this case, is the database row with the matching 11228: ** primary key. 11229: ** 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. 11234: ** 11235: ** There is no conflicting row in this case. The results of invoking the 11236: ** sqlite3changeset_conflict() API are undefined. 11237: ** 11238: ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11239: ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11240: ** handler while processing an INSERT change if the operation would result 11241: ** in duplicate primary key values. 11242: ** 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 11248: ** database in a state containing foreign key violations, the conflict 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(). 11258: ** 11259: ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 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 11262: ** invoked with CHANGESET_CONSTRAINT as the second argument. 11263: ** 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: 11275: /* 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 11283: ** change that caused the conflict is not applied. The session module 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 11289: ** is not the case, any changes applied so far are rolled back and the 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> 11302: ** If this value is returned, any changes applied so far are rolled back 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: /* 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: /* 11466: ** CAPI3REF: Streaming Versions of API functions. 11467: ** 11468: ** The six streaming API xxx_strm() functions serve similar purposes to the 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> 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] 11480: ** </table> 11481: ** 11482: ** Non-streaming functions that accept changesets (or patchsets) as input 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 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 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 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 11521: ** an error state, whereby all subsequent calls to iterator functions 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: ** 11551: ** The sessions module never invokes an xOutput callback with the third 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: */ 11555: SQLITE_API int sqlite3changeset_apply_strm( 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: ); 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( 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: ); 11595: SQLITE_API int sqlite3changeset_invert_strm( 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: ); 11601: SQLITE_API int sqlite3changeset_start_strm( 11602: sqlite3_changeset_iter **pp, 11603: int (*xInput)(void *pIn, void *pData, int *pnData), 11604: void *pIn 11605: ); 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( 11613: sqlite3_session *pSession, 11614: int (*xOutput)(void *pOut, const void *pData, int nData), 11615: void *pOut 11616: ); 11617: SQLITE_API int sqlite3session_patchset_strm( 11618: sqlite3_session *pSession, 11619: int (*xOutput)(void *pOut, const void *pData, int nData), 11620: void *pOut 11621: ); 11622: SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11623: int (*xInput)(void *pIn, void *pData, int *pnData), 11624: void *pIn 11625: ); 11626: SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11627: int (*xOutput)(void *pOut, const void *pData, int nData), 11628: void *pOut 11629: ); 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); 11672: 11673: /* 11674: ** CAPI3REF: Values for sqlite3session_config(). 11675: */ 11676: #define SQLITE_SESSION_CONFIG_STRMSIZE 1 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: ** 11701: ** Interfaces to extend FTS5. Using the interfaces defined in this file, 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): 11745: ** Return a copy of the context pointer the extension function was 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 11752: ** the total number of tokens in column iCol, considering all rows in 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. 11757: ** an OOM condition or IO error), an appropriate SQLite error code is 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. 11771: ** an OOM condition or IO error), an appropriate SQLite error code is 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 11798: ** "detail=none" or "detail=column" option. If the FTS5 table is created 11799: ** with either "detail=none" or "detail=column" and "content=" option 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 11810: ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11811: ** code (i.e. SQLITE_NOMEM) if an error occurs. 11812: ** 11813: ** This API can be quite slow if used with an FTS5 table created with the 11814: ** "detail=none" or "detail=column" option. 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 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 11833: ** function may be used to access the properties of each matched row. 11834: ** Invoking Api.xUserData() returns a copy of the pointer passed as 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: ** 11849: ** Save the pointer passed as the second argument as the extension function's 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 11852: ** the same MATCH query using the xGetAuxdata() API. 11853: ** 11854: ** Each extension function is allocated a single auxiliary data slot for 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 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: ** 11867: ** If an error (e.g. an OOM condition) occurs within this function, 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: ** 11875: ** Returns the current auxiliary data pointer for the fts5 extension 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 11895: ** to use, this API may be faster under some circumstances. To iterate 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 11913: ** "detail=none" or "detail=column" option. If the FTS5 table is created 11914: ** with either "detail=none" or "detail=column" and "content=" option 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 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 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 11947: ** "detail=column" tables. 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: 11961: int (*xTokenize)(Fts5Context*, 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: 11990: /* 11991: ** CUSTOM AUXILIARY FUNCTIONS 11992: *************************************************************************/ 11993: 11994: /************************************************************************* 11995: ** CUSTOM TOKENIZERS 11996: ** 11997: ** Applications may also register custom tokenizer types. A tokenizer 11998: ** is registered by providing fts5 with a populated instance of the 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 12009: ** was registered with FTS5 (the third argument to xCreateTokenizer()). 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: ** 12015: ** The final argument is an output variable. If successful, (*ppOut) 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 12018: ** be returned. In this case, fts5 assumes that the final value of *ppOut 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: 12027: ** This function is expected to tokenize the nText byte string indicated 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> FTS5_TOKENIZE_DOCUMENT - 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: ** 12041: ** <li> FTS5_TOKENIZE_QUERY - A MATCH query is being executed 12042: ** against the FTS index. The tokenizer is being called to tokenize 12043: ** a bareword or quoted string specified as part of the query. 12044: ** 12045: ** <li> (FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX) - 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: ** 12050: ** <li> FTS5_TOKENIZE_AUX - The tokenizer is being invoked to 12051: ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12052: ** function. Or an fts5_api.xColumnSize() request made by the same 12053: ** on a columnsize=0 database. 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 12065: ** normally be set to 0. The exception is if the tokenizer supports 12066: ** synonyms. In this case see the discussion below for details. 12067: ** 12068: ** FTS5 assumes the xToken() callback is invoked for each token in the 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 12082: ** user wishes to query for a phrase such as "first place". Using the 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: ** 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 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: ** 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: 12105: ** 12106: ** <codeblock> 12107: ** ... MATCH 'first place'</codeblock> 12108: ** 12109: ** the tokenizer offers both "1st" and "first" as synonyms for the 12110: ** first token in the MATCH query and FTS5 effectively runs a query 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 12117: ** still appears to contain just two phrases - "(first OR 1st)" 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 12122: ** provides multiple synonyms for each token. So that when a 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 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 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 tflags 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 12150: ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12151: ** There is no limit to the number of synonyms that may be provided for a 12152: ** single token. 12153: ** 12154: ** In many cases, method (1) above is the best approach. It does not add 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 12158: ** token "first" is substituted for "1st" by the tokenizer, then the query: 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: ** 12166: ** For full prefix support, method (3) may be preferred. In this case, 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, 12173: ** a query such as '1s*' will match documents that contain the literal 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 12177: ** extra disk space, as no extra entries are added to the FTS index. 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*); 12191: int (*xTokenize)(Fts5Tokenizer*, 12192: void *pCtx, 12193: int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12194: const char *pText, int nText, 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 *********/