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1.2 misho 1: /* 2: ** 2001 September 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 suppose 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: ** Add the ability to override 'extern' 47: */ 48: #ifndef SQLITE_EXTERN 49: # define SQLITE_EXTERN extern 50: #endif 51: 52: #ifndef SQLITE_API 53: # define SQLITE_API 54: #endif 55: 56: 57: /* 58: ** These no-op macros are used in front of interfaces to mark those 59: ** interfaces as either deprecated or experimental. New applications 60: ** should not use deprecated interfaces - they are support for backwards 61: ** compatibility only. Application writers should be aware that 62: ** experimental interfaces are subject to change in point releases. 63: ** 64: ** These macros used to resolve to various kinds of compiler magic that 65: ** would generate warning messages when they were used. But that 66: ** compiler magic ended up generating such a flurry of bug reports 67: ** that we have taken it all out and gone back to using simple 68: ** noop macros. 69: */ 70: #define SQLITE_DEPRECATED 71: #define SQLITE_EXPERIMENTAL 72: 73: /* 74: ** Ensure these symbols were not defined by some previous header file. 75: */ 76: #ifdef SQLITE_VERSION 77: # undef SQLITE_VERSION 78: #endif 79: #ifdef SQLITE_VERSION_NUMBER 80: # undef SQLITE_VERSION_NUMBER 81: #endif 82: 83: /* 84: ** CAPI3REF: Compile-Time Library Version Numbers 85: ** 86: ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87: ** evaluates to a string literal that is the SQLite version in the 88: ** format "X.Y.Z" where X is the major version number (always 3 for 89: ** SQLite3) and Y is the minor version number and Z is the release number.)^ 90: ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91: ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92: ** numbers used in [SQLITE_VERSION].)^ 93: ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94: ** be larger than the release from which it is derived. Either Y will 95: ** be held constant and Z will be incremented or else Y will be incremented 96: ** and Z will be reset to zero. 97: ** 98: ** Since version 3.6.18, SQLite source code has been stored in the 99: ** <a href="http://www.fossil-scm.org/">Fossil configuration management 100: ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101: ** a string which identifies a particular check-in of SQLite 102: ** within its configuration management system. ^The SQLITE_SOURCE_ID 103: ** string contains the date and time of the check-in (UTC) and an SHA1 104: ** hash of the entire source tree. 105: ** 106: ** See also: [sqlite3_libversion()], 107: ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108: ** [sqlite_version()] and [sqlite_source_id()]. 109: */ 1.3 ! misho 110: #define SQLITE_VERSION "3.7.15.2" ! 111: #define SQLITE_VERSION_NUMBER 3007015 ! 112: #define SQLITE_SOURCE_ID "2013-01-09 11:53:05 c0e09560d26f0a6456be9dd3447f5311eb4f238f" 1.2 misho 113: 114: /* 115: ** CAPI3REF: Run-Time Library Version Numbers 116: ** KEYWORDS: sqlite3_version, sqlite3_sourceid 117: ** 118: ** These interfaces provide the same information as the [SQLITE_VERSION], 119: ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120: ** but are associated with the library instead of the header file. ^(Cautious 121: ** programmers might include assert() statements in their application to 122: ** verify that values returned by these interfaces match the macros in 123: ** the header, and thus insure that the application is 124: ** compiled with matching library and header files. 125: ** 126: ** <blockquote><pre> 127: ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128: ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129: ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130: ** </pre></blockquote>)^ 131: ** 132: ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133: ** macro. ^The sqlite3_libversion() function returns a pointer to the 134: ** to the sqlite3_version[] string constant. The sqlite3_libversion() 135: ** function is provided for use in DLLs since DLL users usually do not have 136: ** direct access to string constants within the DLL. ^The 137: ** sqlite3_libversion_number() function returns an integer equal to 138: ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139: ** a pointer to a string constant whose value is the same as the 140: ** [SQLITE_SOURCE_ID] C preprocessor macro. 141: ** 142: ** See also: [sqlite_version()] and [sqlite_source_id()]. 143: */ 144: SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145: SQLITE_API const char *sqlite3_libversion(void); 146: SQLITE_API const char *sqlite3_sourceid(void); 147: SQLITE_API int sqlite3_libversion_number(void); 148: 149: /* 150: ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151: ** 152: ** ^The sqlite3_compileoption_used() function returns 0 or 1 153: ** indicating whether the specified option was defined at 154: ** compile time. ^The SQLITE_ prefix may be omitted from the 155: ** option name passed to sqlite3_compileoption_used(). 156: ** 157: ** ^The sqlite3_compileoption_get() function allows iterating 158: ** over the list of options that were defined at compile time by 159: ** returning the N-th compile time option string. ^If N is out of range, 160: ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161: ** prefix is omitted from any strings returned by 162: ** sqlite3_compileoption_get(). 163: ** 164: ** ^Support for the diagnostic functions sqlite3_compileoption_used() 165: ** and sqlite3_compileoption_get() may be omitted by specifying the 166: ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167: ** 168: ** See also: SQL functions [sqlite_compileoption_used()] and 169: ** [sqlite_compileoption_get()] and the [compile_options pragma]. 170: */ 171: #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172: SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173: SQLITE_API const char *sqlite3_compileoption_get(int N); 174: #endif 175: 176: /* 177: ** CAPI3REF: Test To See If The Library Is Threadsafe 178: ** 179: ** ^The sqlite3_threadsafe() function returns zero if and only if 180: ** SQLite was compiled with mutexing code omitted due to the 181: ** [SQLITE_THREADSAFE] compile-time option being set to 0. 182: ** 183: ** SQLite can be compiled with or without mutexes. When 184: ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185: ** are enabled and SQLite is threadsafe. When the 186: ** [SQLITE_THREADSAFE] macro is 0, 187: ** the mutexes are omitted. Without the mutexes, it is not safe 188: ** to use SQLite concurrently from more than one thread. 189: ** 190: ** Enabling mutexes incurs a measurable performance penalty. 191: ** So if speed is of utmost importance, it makes sense to disable 192: ** the mutexes. But for maximum safety, mutexes should be enabled. 193: ** ^The default behavior is for mutexes to be enabled. 194: ** 195: ** This interface can be used by an application to make sure that the 196: ** version of SQLite that it is linking against was compiled with 197: ** the desired setting of the [SQLITE_THREADSAFE] macro. 198: ** 199: ** This interface only reports on the compile-time mutex setting 200: ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201: ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202: ** can be fully or partially disabled using a call to [sqlite3_config()] 203: ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204: ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205: ** sqlite3_threadsafe() function shows only the compile-time setting of 206: ** thread safety, not any run-time changes to that setting made by 207: ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208: ** is unchanged by calls to sqlite3_config().)^ 209: ** 210: ** See the [threading mode] documentation for additional information. 211: */ 212: SQLITE_API int sqlite3_threadsafe(void); 213: 214: /* 215: ** CAPI3REF: Database Connection Handle 216: ** KEYWORDS: {database connection} {database connections} 217: ** 218: ** Each open SQLite database is represented by a pointer to an instance of 219: ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220: ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221: ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 1.3 ! misho 222: ** and [sqlite3_close_v2()] are its destructors. There are many other ! 223: ** interfaces (such as 1.2 misho 224: ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 225: ** [sqlite3_busy_timeout()] to name but three) that are methods on an 226: ** sqlite3 object. 227: */ 228: typedef struct sqlite3 sqlite3; 229: 230: /* 231: ** CAPI3REF: 64-Bit Integer Types 232: ** KEYWORDS: sqlite_int64 sqlite_uint64 233: ** 234: ** Because there is no cross-platform way to specify 64-bit integer types 235: ** SQLite includes typedefs for 64-bit signed and unsigned integers. 236: ** 237: ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 238: ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 239: ** compatibility only. 240: ** 241: ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 242: ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 243: ** sqlite3_uint64 and sqlite_uint64 types can store integer values 244: ** between 0 and +18446744073709551615 inclusive. 245: */ 246: #ifdef SQLITE_INT64_TYPE 247: typedef SQLITE_INT64_TYPE sqlite_int64; 248: typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 249: #elif defined(_MSC_VER) || defined(__BORLANDC__) 250: typedef __int64 sqlite_int64; 251: typedef unsigned __int64 sqlite_uint64; 252: #else 253: typedef long long int sqlite_int64; 254: typedef unsigned long long int sqlite_uint64; 255: #endif 256: typedef sqlite_int64 sqlite3_int64; 257: typedef sqlite_uint64 sqlite3_uint64; 258: 259: /* 260: ** If compiling for a processor that lacks floating point support, 261: ** substitute integer for floating-point. 262: */ 263: #ifdef SQLITE_OMIT_FLOATING_POINT 264: # define double sqlite3_int64 265: #endif 266: 267: /* 268: ** CAPI3REF: Closing A Database Connection 269: ** 1.3 ! misho 270: ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors ! 271: ** for the [sqlite3] object. ! 272: ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if ! 273: ** the [sqlite3] object is successfully destroyed and all associated ! 274: ** resources are deallocated. ! 275: ** ! 276: ** ^If the database connection is associated with unfinalized prepared ! 277: ** statements or unfinished sqlite3_backup objects then sqlite3_close() ! 278: ** will leave the database connection open and return [SQLITE_BUSY]. ! 279: ** ^If sqlite3_close_v2() is called with unfinalized prepared statements ! 280: ** and unfinished sqlite3_backups, then the database connection becomes ! 281: ** an unusable "zombie" which will automatically be deallocated when the ! 282: ** last prepared statement is finalized or the last sqlite3_backup is ! 283: ** finished. The sqlite3_close_v2() interface is intended for use with ! 284: ** host languages that are garbage collected, and where the order in which ! 285: ** destructors are called is arbitrary. ! 286: ** ! 287: ** Applications should [sqlite3_finalize | finalize] all [prepared statements], ! 288: ** [sqlite3_blob_close | close] all [BLOB handles], and ! 289: ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated ! 290: ** with the [sqlite3] object prior to attempting to close the object. ^If 1.2 misho 291: ** sqlite3_close() is called on a [database connection] that still has 1.3 ! misho 292: ** outstanding [prepared statements], [BLOB handles], and/or ! 293: ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation ! 294: ** of resources is deferred until all [prepared statements], [BLOB handles], ! 295: ** and [sqlite3_backup] objects are also destroyed. 1.2 misho 296: ** 1.3 ! misho 297: ** ^If an [sqlite3] object is destroyed while a transaction is open, 1.2 misho 298: ** the transaction is automatically rolled back. 299: ** 1.3 ! misho 300: ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] ! 301: ** must be either a NULL 1.2 misho 302: ** pointer or an [sqlite3] object pointer obtained 303: ** from [sqlite3_open()], [sqlite3_open16()], or 304: ** [sqlite3_open_v2()], and not previously closed. 1.3 ! misho 305: ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer ! 306: ** argument is a harmless no-op. 1.2 misho 307: */ 1.3 ! misho 308: SQLITE_API int sqlite3_close(sqlite3*); ! 309: SQLITE_API int sqlite3_close_v2(sqlite3*); 1.2 misho 310: 311: /* 312: ** The type for a callback function. 313: ** This is legacy and deprecated. It is included for historical 314: ** compatibility and is not documented. 315: */ 316: typedef int (*sqlite3_callback)(void*,int,char**, char**); 317: 318: /* 319: ** CAPI3REF: One-Step Query Execution Interface 320: ** 321: ** The sqlite3_exec() interface is a convenience wrapper around 322: ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 323: ** that allows an application to run multiple statements of SQL 324: ** without having to use a lot of C code. 325: ** 326: ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 327: ** semicolon-separate SQL statements passed into its 2nd argument, 328: ** in the context of the [database connection] passed in as its 1st 329: ** argument. ^If the callback function of the 3rd argument to 330: ** sqlite3_exec() is not NULL, then it is invoked for each result row 331: ** coming out of the evaluated SQL statements. ^The 4th argument to 332: ** sqlite3_exec() is relayed through to the 1st argument of each 333: ** callback invocation. ^If the callback pointer to sqlite3_exec() 334: ** is NULL, then no callback is ever invoked and result rows are 335: ** ignored. 336: ** 337: ** ^If an error occurs while evaluating the SQL statements passed into 338: ** sqlite3_exec(), then execution of the current statement stops and 339: ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 340: ** is not NULL then any error message is written into memory obtained 341: ** from [sqlite3_malloc()] and passed back through the 5th parameter. 342: ** To avoid memory leaks, the application should invoke [sqlite3_free()] 343: ** on error message strings returned through the 5th parameter of 344: ** of sqlite3_exec() after the error message string is no longer needed. 345: ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 346: ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 347: ** NULL before returning. 348: ** 349: ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 350: ** routine returns SQLITE_ABORT without invoking the callback again and 351: ** without running any subsequent SQL statements. 352: ** 353: ** ^The 2nd argument to the sqlite3_exec() callback function is the 354: ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 355: ** callback is an array of pointers to strings obtained as if from 356: ** [sqlite3_column_text()], one for each column. ^If an element of a 357: ** result row is NULL then the corresponding string pointer for the 358: ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 359: ** sqlite3_exec() callback is an array of pointers to strings where each 360: ** entry represents the name of corresponding result column as obtained 361: ** from [sqlite3_column_name()]. 362: ** 363: ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 364: ** to an empty string, or a pointer that contains only whitespace and/or 365: ** SQL comments, then no SQL statements are evaluated and the database 366: ** is not changed. 367: ** 368: ** Restrictions: 369: ** 370: ** <ul> 371: ** <li> The application must insure that the 1st parameter to sqlite3_exec() 372: ** is a valid and open [database connection]. 373: ** <li> The application must not close [database connection] specified by 374: ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 375: ** <li> The application must not modify the SQL statement text passed into 376: ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 377: ** </ul> 378: */ 379: SQLITE_API int sqlite3_exec( 380: sqlite3*, /* An open database */ 381: const char *sql, /* SQL to be evaluated */ 382: int (*callback)(void*,int,char**,char**), /* Callback function */ 383: void *, /* 1st argument to callback */ 384: char **errmsg /* Error msg written here */ 385: ); 386: 387: /* 388: ** CAPI3REF: Result Codes 389: ** KEYWORDS: SQLITE_OK {error code} {error codes} 390: ** KEYWORDS: {result code} {result codes} 391: ** 392: ** Many SQLite functions return an integer result code from the set shown 393: ** here in order to indicate success or failure. 394: ** 395: ** New error codes may be added in future versions of SQLite. 396: ** 397: ** See also: [SQLITE_IOERR_READ | extended result codes], 398: ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 399: */ 400: #define SQLITE_OK 0 /* Successful result */ 401: /* beginning-of-error-codes */ 402: #define SQLITE_ERROR 1 /* SQL error or missing database */ 403: #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 404: #define SQLITE_PERM 3 /* Access permission denied */ 405: #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 406: #define SQLITE_BUSY 5 /* The database file is locked */ 407: #define SQLITE_LOCKED 6 /* A table in the database is locked */ 408: #define SQLITE_NOMEM 7 /* A malloc() failed */ 409: #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 410: #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 411: #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 412: #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 413: #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 414: #define SQLITE_FULL 13 /* Insertion failed because database is full */ 415: #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 416: #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 417: #define SQLITE_EMPTY 16 /* Database is empty */ 418: #define SQLITE_SCHEMA 17 /* The database schema changed */ 419: #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 420: #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 421: #define SQLITE_MISMATCH 20 /* Data type mismatch */ 422: #define SQLITE_MISUSE 21 /* Library used incorrectly */ 423: #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 424: #define SQLITE_AUTH 23 /* Authorization denied */ 425: #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 426: #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 427: #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 428: #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 429: #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 430: /* end-of-error-codes */ 431: 432: /* 433: ** CAPI3REF: Extended Result Codes 434: ** KEYWORDS: {extended error code} {extended error codes} 435: ** KEYWORDS: {extended result code} {extended result codes} 436: ** 437: ** In its default configuration, SQLite API routines return one of 26 integer 438: ** [SQLITE_OK | result codes]. However, experience has shown that many of 439: ** these result codes are too coarse-grained. They do not provide as 440: ** much information about problems as programmers might like. In an effort to 441: ** address this, newer versions of SQLite (version 3.3.8 and later) include 442: ** support for additional result codes that provide more detailed information 443: ** about errors. The extended result codes are enabled or disabled 444: ** on a per database connection basis using the 445: ** [sqlite3_extended_result_codes()] API. 446: ** 447: ** Some of the available extended result codes are listed here. 448: ** One may expect the number of extended result codes will be expand 449: ** over time. Software that uses extended result codes should expect 450: ** to see new result codes in future releases of SQLite. 451: ** 452: ** The SQLITE_OK result code will never be extended. It will always 453: ** be exactly zero. 454: */ 455: #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 456: #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 457: #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 458: #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 459: #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 460: #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 461: #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 462: #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 463: #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 464: #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 465: #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 466: #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 467: #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 468: #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 469: #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 470: #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 471: #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 472: #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 473: #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 474: #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 475: #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 476: #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 1.3 ! misho 477: #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 1.2 misho 478: #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 479: #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 480: #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 1.3 ! misho 481: #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) ! 482: #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 1.2 misho 483: #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 484: #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 485: #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 1.3 ! misho 486: #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 1.2 misho 487: 488: /* 489: ** CAPI3REF: Flags For File Open Operations 490: ** 491: ** These bit values are intended for use in the 492: ** 3rd parameter to the [sqlite3_open_v2()] interface and 493: ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 494: */ 495: #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 496: #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 497: #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 498: #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 499: #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 500: #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 501: #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 1.3 ! misho 502: #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 1.2 misho 503: #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 504: #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 505: #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 506: #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 507: #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 508: #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 509: #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 510: #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 511: #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 512: #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 513: #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 514: #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 515: 516: /* Reserved: 0x00F00000 */ 517: 518: /* 519: ** CAPI3REF: Device Characteristics 520: ** 521: ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 1.3 ! misho 522: ** object returns an integer which is a vector of these 1.2 misho 523: ** bit values expressing I/O characteristics of the mass storage 524: ** device that holds the file that the [sqlite3_io_methods] 525: ** refers to. 526: ** 527: ** The SQLITE_IOCAP_ATOMIC property means that all writes of 528: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 529: ** mean that writes of blocks that are nnn bytes in size and 530: ** are aligned to an address which is an integer multiple of 531: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 532: ** that when data is appended to a file, the data is appended 533: ** first then the size of the file is extended, never the other 534: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 535: ** information is written to disk in the same order as calls 536: ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 537: ** after reboot following a crash or power loss, the only bytes in a 538: ** file that were written at the application level might have changed 539: ** and that adjacent bytes, even bytes within the same sector are 540: ** guaranteed to be unchanged. 541: */ 542: #define SQLITE_IOCAP_ATOMIC 0x00000001 543: #define SQLITE_IOCAP_ATOMIC512 0x00000002 544: #define SQLITE_IOCAP_ATOMIC1K 0x00000004 545: #define SQLITE_IOCAP_ATOMIC2K 0x00000008 546: #define SQLITE_IOCAP_ATOMIC4K 0x00000010 547: #define SQLITE_IOCAP_ATOMIC8K 0x00000020 548: #define SQLITE_IOCAP_ATOMIC16K 0x00000040 549: #define SQLITE_IOCAP_ATOMIC32K 0x00000080 550: #define SQLITE_IOCAP_ATOMIC64K 0x00000100 551: #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 552: #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 553: #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 554: #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 555: 556: /* 557: ** CAPI3REF: File Locking Levels 558: ** 559: ** SQLite uses one of these integer values as the second 560: ** argument to calls it makes to the xLock() and xUnlock() methods 561: ** of an [sqlite3_io_methods] object. 562: */ 563: #define SQLITE_LOCK_NONE 0 564: #define SQLITE_LOCK_SHARED 1 565: #define SQLITE_LOCK_RESERVED 2 566: #define SQLITE_LOCK_PENDING 3 567: #define SQLITE_LOCK_EXCLUSIVE 4 568: 569: /* 570: ** CAPI3REF: Synchronization Type Flags 571: ** 572: ** When SQLite invokes the xSync() method of an 573: ** [sqlite3_io_methods] object it uses a combination of 574: ** these integer values as the second argument. 575: ** 576: ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 577: ** sync operation only needs to flush data to mass storage. Inode 578: ** information need not be flushed. If the lower four bits of the flag 579: ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 580: ** If the lower four bits equal SQLITE_SYNC_FULL, that means 581: ** to use Mac OS X style fullsync instead of fsync(). 582: ** 583: ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 584: ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 585: ** settings. The [synchronous pragma] determines when calls to the 586: ** xSync VFS method occur and applies uniformly across all platforms. 587: ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 588: ** energetic or rigorous or forceful the sync operations are and 589: ** only make a difference on Mac OSX for the default SQLite code. 590: ** (Third-party VFS implementations might also make the distinction 591: ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 592: ** operating systems natively supported by SQLite, only Mac OSX 593: ** cares about the difference.) 594: */ 595: #define SQLITE_SYNC_NORMAL 0x00002 596: #define SQLITE_SYNC_FULL 0x00003 597: #define SQLITE_SYNC_DATAONLY 0x00010 598: 599: /* 600: ** CAPI3REF: OS Interface Open File Handle 601: ** 602: ** An [sqlite3_file] object represents an open file in the 603: ** [sqlite3_vfs | OS interface layer]. Individual OS interface 604: ** implementations will 605: ** want to subclass this object by appending additional fields 606: ** for their own use. The pMethods entry is a pointer to an 607: ** [sqlite3_io_methods] object that defines methods for performing 608: ** I/O operations on the open file. 609: */ 610: typedef struct sqlite3_file sqlite3_file; 611: struct sqlite3_file { 612: const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 613: }; 614: 615: /* 616: ** CAPI3REF: OS Interface File Virtual Methods Object 617: ** 618: ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 619: ** [sqlite3_file] object (or, more commonly, a subclass of the 620: ** [sqlite3_file] object) with a pointer to an instance of this object. 621: ** This object defines the methods used to perform various operations 622: ** against the open file represented by the [sqlite3_file] object. 623: ** 624: ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 625: ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 626: ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 627: ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 628: ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 629: ** to NULL. 630: ** 631: ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 632: ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 633: ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 634: ** flag may be ORed in to indicate that only the data of the file 635: ** and not its inode needs to be synced. 636: ** 637: ** The integer values to xLock() and xUnlock() are one of 638: ** <ul> 639: ** <li> [SQLITE_LOCK_NONE], 640: ** <li> [SQLITE_LOCK_SHARED], 641: ** <li> [SQLITE_LOCK_RESERVED], 642: ** <li> [SQLITE_LOCK_PENDING], or 643: ** <li> [SQLITE_LOCK_EXCLUSIVE]. 644: ** </ul> 645: ** xLock() increases the lock. xUnlock() decreases the lock. 646: ** The xCheckReservedLock() method checks whether any database connection, 647: ** either in this process or in some other process, is holding a RESERVED, 648: ** PENDING, or EXCLUSIVE lock on the file. It returns true 649: ** if such a lock exists and false otherwise. 650: ** 651: ** The xFileControl() method is a generic interface that allows custom 652: ** VFS implementations to directly control an open file using the 653: ** [sqlite3_file_control()] interface. The second "op" argument is an 654: ** integer opcode. The third argument is a generic pointer intended to 655: ** point to a structure that may contain arguments or space in which to 656: ** write return values. Potential uses for xFileControl() might be 657: ** functions to enable blocking locks with timeouts, to change the 658: ** locking strategy (for example to use dot-file locks), to inquire 659: ** about the status of a lock, or to break stale locks. The SQLite 660: ** core reserves all opcodes less than 100 for its own use. 661: ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 662: ** Applications that define a custom xFileControl method should use opcodes 663: ** greater than 100 to avoid conflicts. VFS implementations should 664: ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 665: ** recognize. 666: ** 667: ** The xSectorSize() method returns the sector size of the 668: ** device that underlies the file. The sector size is the 669: ** minimum write that can be performed without disturbing 670: ** other bytes in the file. The xDeviceCharacteristics() 671: ** method returns a bit vector describing behaviors of the 672: ** underlying device: 673: ** 674: ** <ul> 675: ** <li> [SQLITE_IOCAP_ATOMIC] 676: ** <li> [SQLITE_IOCAP_ATOMIC512] 677: ** <li> [SQLITE_IOCAP_ATOMIC1K] 678: ** <li> [SQLITE_IOCAP_ATOMIC2K] 679: ** <li> [SQLITE_IOCAP_ATOMIC4K] 680: ** <li> [SQLITE_IOCAP_ATOMIC8K] 681: ** <li> [SQLITE_IOCAP_ATOMIC16K] 682: ** <li> [SQLITE_IOCAP_ATOMIC32K] 683: ** <li> [SQLITE_IOCAP_ATOMIC64K] 684: ** <li> [SQLITE_IOCAP_SAFE_APPEND] 685: ** <li> [SQLITE_IOCAP_SEQUENTIAL] 686: ** </ul> 687: ** 688: ** The SQLITE_IOCAP_ATOMIC property means that all writes of 689: ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 690: ** mean that writes of blocks that are nnn bytes in size and 691: ** are aligned to an address which is an integer multiple of 692: ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 693: ** that when data is appended to a file, the data is appended 694: ** first then the size of the file is extended, never the other 695: ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 696: ** information is written to disk in the same order as calls 697: ** to xWrite(). 698: ** 699: ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 700: ** in the unread portions of the buffer with zeros. A VFS that 701: ** fails to zero-fill short reads might seem to work. However, 702: ** failure to zero-fill short reads will eventually lead to 703: ** database corruption. 704: */ 705: typedef struct sqlite3_io_methods sqlite3_io_methods; 706: struct sqlite3_io_methods { 707: int iVersion; 708: int (*xClose)(sqlite3_file*); 709: int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 710: int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 711: int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 712: int (*xSync)(sqlite3_file*, int flags); 713: int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 714: int (*xLock)(sqlite3_file*, int); 715: int (*xUnlock)(sqlite3_file*, int); 716: int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 717: int (*xFileControl)(sqlite3_file*, int op, void *pArg); 718: int (*xSectorSize)(sqlite3_file*); 719: int (*xDeviceCharacteristics)(sqlite3_file*); 720: /* Methods above are valid for version 1 */ 721: int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 722: int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 723: void (*xShmBarrier)(sqlite3_file*); 724: int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 725: /* Methods above are valid for version 2 */ 726: /* Additional methods may be added in future releases */ 727: }; 728: 729: /* 730: ** CAPI3REF: Standard File Control Opcodes 731: ** 732: ** These integer constants are opcodes for the xFileControl method 733: ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 734: ** interface. 735: ** 736: ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 737: ** opcode causes the xFileControl method to write the current state of 738: ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 739: ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 740: ** into an integer that the pArg argument points to. This capability 741: ** is used during testing and only needs to be supported when SQLITE_TEST 742: ** is defined. 1.3 ! misho 743: ** <ul> ! 744: ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 1.2 misho 745: ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 746: ** layer a hint of how large the database file will grow to be during the 747: ** current transaction. This hint is not guaranteed to be accurate but it 748: ** is often close. The underlying VFS might choose to preallocate database 749: ** file space based on this hint in order to help writes to the database 750: ** file run faster. 751: ** 1.3 ! misho 752: ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 1.2 misho 753: ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 754: ** extends and truncates the database file in chunks of a size specified 755: ** by the user. The fourth argument to [sqlite3_file_control()] should 756: ** point to an integer (type int) containing the new chunk-size to use 757: ** for the nominated database. Allocating database file space in large 758: ** chunks (say 1MB at a time), may reduce file-system fragmentation and 759: ** improve performance on some systems. 760: ** 1.3 ! misho 761: ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 1.2 misho 762: ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 763: ** to the [sqlite3_file] object associated with a particular database 764: ** connection. See the [sqlite3_file_control()] documentation for 765: ** additional information. 766: ** 1.3 ! misho 767: ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 1.2 misho 768: ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by 769: ** SQLite and sent to all VFSes in place of a call to the xSync method 770: ** when the database connection has [PRAGMA synchronous] set to OFF.)^ 771: ** Some specialized VFSes need this signal in order to operate correctly 772: ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 773: ** VFSes do not need this signal and should silently ignore this opcode. 774: ** Applications should not call [sqlite3_file_control()] with this 775: ** opcode as doing so may disrupt the operation of the specialized VFSes 776: ** that do require it. 777: ** 1.3 ! misho 778: ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 1.2 misho 779: ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 780: ** retry counts and intervals for certain disk I/O operations for the 781: ** windows [VFS] in order to provide robustness in the presence of 782: ** anti-virus programs. By default, the windows VFS will retry file read, 783: ** file write, and file delete operations up to 10 times, with a delay 784: ** of 25 milliseconds before the first retry and with the delay increasing 785: ** by an additional 25 milliseconds with each subsequent retry. This 786: ** opcode allows these two values (10 retries and 25 milliseconds of delay) 787: ** to be adjusted. The values are changed for all database connections 788: ** within the same process. The argument is a pointer to an array of two 789: ** integers where the first integer i the new retry count and the second 790: ** integer is the delay. If either integer is negative, then the setting 791: ** is not changed but instead the prior value of that setting is written 792: ** into the array entry, allowing the current retry settings to be 793: ** interrogated. The zDbName parameter is ignored. 794: ** 1.3 ! misho 795: ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 1.2 misho 796: ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 1.3 ! misho 797: ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 1.2 misho 798: ** write ahead log and shared memory files used for transaction control 799: ** are automatically deleted when the latest connection to the database 800: ** closes. Setting persistent WAL mode causes those files to persist after 801: ** close. Persisting the files is useful when other processes that do not 802: ** have write permission on the directory containing the database file want 803: ** to read the database file, as the WAL and shared memory files must exist 804: ** in order for the database to be readable. The fourth parameter to 805: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 806: ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 807: ** WAL mode. If the integer is -1, then it is overwritten with the current 808: ** WAL persistence setting. 809: ** 1.3 ! misho 810: ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 1.2 misho 811: ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 812: ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 813: ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 814: ** xDeviceCharacteristics methods. The fourth parameter to 815: ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 816: ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 817: ** mode. If the integer is -1, then it is overwritten with the current 818: ** zero-damage mode setting. 819: ** 1.3 ! misho 820: ** <li>[[SQLITE_FCNTL_OVERWRITE]] 1.2 misho 821: ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 822: ** a write transaction to indicate that, unless it is rolled back for some 823: ** reason, the entire database file will be overwritten by the current 824: ** transaction. This is used by VACUUM operations. 825: ** 1.3 ! misho 826: ** <li>[[SQLITE_FCNTL_VFSNAME]] 1.2 misho 827: ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 828: ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 829: ** final bottom-level VFS are written into memory obtained from 830: ** [sqlite3_malloc()] and the result is stored in the char* variable 831: ** that the fourth parameter of [sqlite3_file_control()] points to. 832: ** The caller is responsible for freeing the memory when done. As with 833: ** all file-control actions, there is no guarantee that this will actually 834: ** do anything. Callers should initialize the char* variable to a NULL 835: ** pointer in case this file-control is not implemented. This file-control 836: ** is intended for diagnostic use only. 1.3 ! misho 837: ** ! 838: ** <li>[[SQLITE_FCNTL_PRAGMA]] ! 839: ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] ! 840: ** file control is sent to the open [sqlite3_file] object corresponding ! 841: ** to the database file to which the pragma statement refers. ^The argument ! 842: ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of ! 843: ** pointers to strings (char**) in which the second element of the array ! 844: ** is the name of the pragma and the third element is the argument to the ! 845: ** pragma or NULL if the pragma has no argument. ^The handler for an ! 846: ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element ! 847: ** of the char** argument point to a string obtained from [sqlite3_mprintf()] ! 848: ** or the equivalent and that string will become the result of the pragma or ! 849: ** the error message if the pragma fails. ^If the ! 850: ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal ! 851: ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] ! 852: ** file control returns [SQLITE_OK], then the parser assumes that the ! 853: ** VFS has handled the PRAGMA itself and the parser generates a no-op ! 854: ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns ! 855: ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means ! 856: ** that the VFS encountered an error while handling the [PRAGMA] and the ! 857: ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] ! 858: ** file control occurs at the beginning of pragma statement analysis and so ! 859: ** it is able to override built-in [PRAGMA] statements. ! 860: ** ! 861: ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] ! 862: ** ^This file-control may be invoked by SQLite on the database file handle ! 863: ** shortly after it is opened in order to provide a custom VFS with access ! 864: ** to the connections busy-handler callback. The argument is of type (void **) ! 865: ** - an array of two (void *) values. The first (void *) actually points ! 866: ** to a function of type (int (*)(void *)). In order to invoke the connections ! 867: ** busy-handler, this function should be invoked with the second (void *) in ! 868: ** the array as the only argument. If it returns non-zero, then the operation ! 869: ** should be retried. If it returns zero, the custom VFS should abandon the ! 870: ** current operation. ! 871: ** ! 872: ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] ! 873: ** ^Application can invoke this file-control to have SQLite generate a ! 874: ** temporary filename using the same algorithm that is followed to generate ! 875: ** temporary filenames for TEMP tables and other internal uses. The ! 876: ** argument should be a char** which will be filled with the filename ! 877: ** written into memory obtained from [sqlite3_malloc()]. The caller should ! 878: ** invoke [sqlite3_free()] on the result to avoid a memory leak. ! 879: ** ! 880: ** </ul> 1.2 misho 881: */ 882: #define SQLITE_FCNTL_LOCKSTATE 1 883: #define SQLITE_GET_LOCKPROXYFILE 2 884: #define SQLITE_SET_LOCKPROXYFILE 3 885: #define SQLITE_LAST_ERRNO 4 886: #define SQLITE_FCNTL_SIZE_HINT 5 887: #define SQLITE_FCNTL_CHUNK_SIZE 6 888: #define SQLITE_FCNTL_FILE_POINTER 7 889: #define SQLITE_FCNTL_SYNC_OMITTED 8 890: #define SQLITE_FCNTL_WIN32_AV_RETRY 9 891: #define SQLITE_FCNTL_PERSIST_WAL 10 892: #define SQLITE_FCNTL_OVERWRITE 11 893: #define SQLITE_FCNTL_VFSNAME 12 894: #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1.3 ! misho 895: #define SQLITE_FCNTL_PRAGMA 14 ! 896: #define SQLITE_FCNTL_BUSYHANDLER 15 ! 897: #define SQLITE_FCNTL_TEMPFILENAME 16 1.2 misho 898: 899: /* 900: ** CAPI3REF: Mutex Handle 901: ** 902: ** The mutex module within SQLite defines [sqlite3_mutex] to be an 903: ** abstract type for a mutex object. The SQLite core never looks 904: ** at the internal representation of an [sqlite3_mutex]. It only 905: ** deals with pointers to the [sqlite3_mutex] object. 906: ** 907: ** Mutexes are created using [sqlite3_mutex_alloc()]. 908: */ 909: typedef struct sqlite3_mutex sqlite3_mutex; 910: 911: /* 912: ** CAPI3REF: OS Interface Object 913: ** 914: ** An instance of the sqlite3_vfs object defines the interface between 915: ** the SQLite core and the underlying operating system. The "vfs" 916: ** in the name of the object stands for "virtual file system". See 917: ** the [VFS | VFS documentation] for further information. 918: ** 919: ** The value of the iVersion field is initially 1 but may be larger in 920: ** future versions of SQLite. Additional fields may be appended to this 921: ** object when the iVersion value is increased. Note that the structure 922: ** of the sqlite3_vfs object changes in the transaction between 923: ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 924: ** modified. 925: ** 926: ** The szOsFile field is the size of the subclassed [sqlite3_file] 927: ** structure used by this VFS. mxPathname is the maximum length of 928: ** a pathname in this VFS. 929: ** 930: ** Registered sqlite3_vfs objects are kept on a linked list formed by 931: ** the pNext pointer. The [sqlite3_vfs_register()] 932: ** and [sqlite3_vfs_unregister()] interfaces manage this list 933: ** in a thread-safe way. The [sqlite3_vfs_find()] interface 934: ** searches the list. Neither the application code nor the VFS 935: ** implementation should use the pNext pointer. 936: ** 937: ** The pNext field is the only field in the sqlite3_vfs 938: ** structure that SQLite will ever modify. SQLite will only access 939: ** or modify this field while holding a particular static mutex. 940: ** The application should never modify anything within the sqlite3_vfs 941: ** object once the object has been registered. 942: ** 943: ** The zName field holds the name of the VFS module. The name must 944: ** be unique across all VFS modules. 945: ** 946: ** [[sqlite3_vfs.xOpen]] 947: ** ^SQLite guarantees that the zFilename parameter to xOpen 948: ** is either a NULL pointer or string obtained 949: ** from xFullPathname() with an optional suffix added. 950: ** ^If a suffix is added to the zFilename parameter, it will 951: ** consist of a single "-" character followed by no more than 952: ** 11 alphanumeric and/or "-" characters. 953: ** ^SQLite further guarantees that 954: ** the string will be valid and unchanged until xClose() is 955: ** called. Because of the previous sentence, 956: ** the [sqlite3_file] can safely store a pointer to the 957: ** filename if it needs to remember the filename for some reason. 958: ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 959: ** must invent its own temporary name for the file. ^Whenever the 960: ** xFilename parameter is NULL it will also be the case that the 961: ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 962: ** 963: ** The flags argument to xOpen() includes all bits set in 964: ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 965: ** or [sqlite3_open16()] is used, then flags includes at least 966: ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 967: ** If xOpen() opens a file read-only then it sets *pOutFlags to 968: ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 969: ** 970: ** ^(SQLite will also add one of the following flags to the xOpen() 971: ** call, depending on the object being opened: 972: ** 973: ** <ul> 974: ** <li> [SQLITE_OPEN_MAIN_DB] 975: ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 976: ** <li> [SQLITE_OPEN_TEMP_DB] 977: ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 978: ** <li> [SQLITE_OPEN_TRANSIENT_DB] 979: ** <li> [SQLITE_OPEN_SUBJOURNAL] 980: ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 981: ** <li> [SQLITE_OPEN_WAL] 982: ** </ul>)^ 983: ** 984: ** The file I/O implementation can use the object type flags to 985: ** change the way it deals with files. For example, an application 986: ** that does not care about crash recovery or rollback might make 987: ** the open of a journal file a no-op. Writes to this journal would 988: ** also be no-ops, and any attempt to read the journal would return 989: ** SQLITE_IOERR. Or the implementation might recognize that a database 990: ** file will be doing page-aligned sector reads and writes in a random 991: ** order and set up its I/O subsystem accordingly. 992: ** 993: ** SQLite might also add one of the following flags to the xOpen method: 994: ** 995: ** <ul> 996: ** <li> [SQLITE_OPEN_DELETEONCLOSE] 997: ** <li> [SQLITE_OPEN_EXCLUSIVE] 998: ** </ul> 999: ** 1000: ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1001: ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1002: ** will be set for TEMP databases and their journals, transient 1003: ** databases, and subjournals. 1004: ** 1005: ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1006: ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1007: ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1008: ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1009: ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1010: ** be created, and that it is an error if it already exists. 1011: ** It is <i>not</i> used to indicate the file should be opened 1012: ** for exclusive access. 1013: ** 1014: ** ^At least szOsFile bytes of memory are allocated by SQLite 1015: ** to hold the [sqlite3_file] structure passed as the third 1016: ** argument to xOpen. The xOpen method does not have to 1017: ** allocate the structure; it should just fill it in. Note that 1018: ** the xOpen method must set the sqlite3_file.pMethods to either 1019: ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1020: ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1021: ** element will be valid after xOpen returns regardless of the success 1022: ** or failure of the xOpen call. 1023: ** 1024: ** [[sqlite3_vfs.xAccess]] 1025: ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1026: ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1027: ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1028: ** to test whether a file is at least readable. The file can be a 1029: ** directory. 1030: ** 1031: ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1032: ** output buffer xFullPathname. The exact size of the output buffer 1033: ** is also passed as a parameter to both methods. If the output buffer 1034: ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1035: ** handled as a fatal error by SQLite, vfs implementations should endeavor 1036: ** to prevent this by setting mxPathname to a sufficiently large value. 1037: ** 1038: ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1039: ** interfaces are not strictly a part of the filesystem, but they are 1040: ** included in the VFS structure for completeness. 1041: ** The xRandomness() function attempts to return nBytes bytes 1042: ** of good-quality randomness into zOut. The return value is 1043: ** the actual number of bytes of randomness obtained. 1044: ** The xSleep() method causes the calling thread to sleep for at 1045: ** least the number of microseconds given. ^The xCurrentTime() 1046: ** method returns a Julian Day Number for the current date and time as 1047: ** a floating point value. 1048: ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1049: ** Day Number multiplied by 86400000 (the number of milliseconds in 1050: ** a 24-hour day). 1051: ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1052: ** date and time if that method is available (if iVersion is 2 or 1053: ** greater and the function pointer is not NULL) and will fall back 1054: ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1055: ** 1056: ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1057: ** are not used by the SQLite core. These optional interfaces are provided 1058: ** by some VFSes to facilitate testing of the VFS code. By overriding 1059: ** system calls with functions under its control, a test program can 1060: ** simulate faults and error conditions that would otherwise be difficult 1061: ** or impossible to induce. The set of system calls that can be overridden 1062: ** varies from one VFS to another, and from one version of the same VFS to the 1063: ** next. Applications that use these interfaces must be prepared for any 1064: ** or all of these interfaces to be NULL or for their behavior to change 1065: ** from one release to the next. Applications must not attempt to access 1066: ** any of these methods if the iVersion of the VFS is less than 3. 1067: */ 1068: typedef struct sqlite3_vfs sqlite3_vfs; 1069: typedef void (*sqlite3_syscall_ptr)(void); 1070: struct sqlite3_vfs { 1071: int iVersion; /* Structure version number (currently 3) */ 1072: int szOsFile; /* Size of subclassed sqlite3_file */ 1073: int mxPathname; /* Maximum file pathname length */ 1074: sqlite3_vfs *pNext; /* Next registered VFS */ 1075: const char *zName; /* Name of this virtual file system */ 1076: void *pAppData; /* Pointer to application-specific data */ 1077: int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1078: int flags, int *pOutFlags); 1079: int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1080: int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1081: int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1082: void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1083: void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1084: void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1085: void (*xDlClose)(sqlite3_vfs*, void*); 1086: int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1087: int (*xSleep)(sqlite3_vfs*, int microseconds); 1088: int (*xCurrentTime)(sqlite3_vfs*, double*); 1089: int (*xGetLastError)(sqlite3_vfs*, int, char *); 1090: /* 1091: ** The methods above are in version 1 of the sqlite_vfs object 1092: ** definition. Those that follow are added in version 2 or later 1093: */ 1094: int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1095: /* 1096: ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1097: ** Those below are for version 3 and greater. 1098: */ 1099: int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1100: sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1101: const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1102: /* 1103: ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1104: ** New fields may be appended in figure versions. The iVersion 1105: ** value will increment whenever this happens. 1106: */ 1107: }; 1108: 1109: /* 1110: ** CAPI3REF: Flags for the xAccess VFS method 1111: ** 1112: ** These integer constants can be used as the third parameter to 1113: ** the xAccess method of an [sqlite3_vfs] object. They determine 1114: ** what kind of permissions the xAccess method is looking for. 1115: ** With SQLITE_ACCESS_EXISTS, the xAccess method 1116: ** simply checks whether the file exists. 1117: ** With SQLITE_ACCESS_READWRITE, the xAccess method 1118: ** checks whether the named directory is both readable and writable 1119: ** (in other words, if files can be added, removed, and renamed within 1120: ** the directory). 1121: ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1122: ** [temp_store_directory pragma], though this could change in a future 1123: ** release of SQLite. 1124: ** With SQLITE_ACCESS_READ, the xAccess method 1125: ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1126: ** currently unused, though it might be used in a future release of 1127: ** SQLite. 1128: */ 1129: #define SQLITE_ACCESS_EXISTS 0 1130: #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1131: #define SQLITE_ACCESS_READ 2 /* Unused */ 1132: 1133: /* 1134: ** CAPI3REF: Flags for the xShmLock VFS method 1135: ** 1136: ** These integer constants define the various locking operations 1137: ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1138: ** following are the only legal combinations of flags to the 1139: ** xShmLock method: 1140: ** 1141: ** <ul> 1142: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1143: ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1144: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1145: ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1146: ** </ul> 1147: ** 1148: ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1149: ** was given no the corresponding lock. 1150: ** 1151: ** The xShmLock method can transition between unlocked and SHARED or 1152: ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1153: ** and EXCLUSIVE. 1154: */ 1155: #define SQLITE_SHM_UNLOCK 1 1156: #define SQLITE_SHM_LOCK 2 1157: #define SQLITE_SHM_SHARED 4 1158: #define SQLITE_SHM_EXCLUSIVE 8 1159: 1160: /* 1161: ** CAPI3REF: Maximum xShmLock index 1162: ** 1163: ** The xShmLock method on [sqlite3_io_methods] may use values 1164: ** between 0 and this upper bound as its "offset" argument. 1165: ** The SQLite core will never attempt to acquire or release a 1166: ** lock outside of this range 1167: */ 1168: #define SQLITE_SHM_NLOCK 8 1169: 1170: 1171: /* 1172: ** CAPI3REF: Initialize The SQLite Library 1173: ** 1174: ** ^The sqlite3_initialize() routine initializes the 1175: ** SQLite library. ^The sqlite3_shutdown() routine 1176: ** deallocates any resources that were allocated by sqlite3_initialize(). 1177: ** These routines are designed to aid in process initialization and 1178: ** shutdown on embedded systems. Workstation applications using 1179: ** SQLite normally do not need to invoke either of these routines. 1180: ** 1181: ** A call to sqlite3_initialize() is an "effective" call if it is 1182: ** the first time sqlite3_initialize() is invoked during the lifetime of 1183: ** the process, or if it is the first time sqlite3_initialize() is invoked 1184: ** following a call to sqlite3_shutdown(). ^(Only an effective call 1185: ** of sqlite3_initialize() does any initialization. All other calls 1186: ** are harmless no-ops.)^ 1187: ** 1188: ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1189: ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1190: ** an effective call to sqlite3_shutdown() does any deinitialization. 1191: ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1192: ** 1193: ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1194: ** is not. The sqlite3_shutdown() interface must only be called from a 1195: ** single thread. All open [database connections] must be closed and all 1196: ** other SQLite resources must be deallocated prior to invoking 1197: ** sqlite3_shutdown(). 1198: ** 1199: ** Among other things, ^sqlite3_initialize() will invoke 1200: ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1201: ** will invoke sqlite3_os_end(). 1202: ** 1203: ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1204: ** ^If for some reason, sqlite3_initialize() is unable to initialize 1205: ** the library (perhaps it is unable to allocate a needed resource such 1206: ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1207: ** 1208: ** ^The sqlite3_initialize() routine is called internally by many other 1209: ** SQLite interfaces so that an application usually does not need to 1210: ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1211: ** calls sqlite3_initialize() so the SQLite library will be automatically 1212: ** initialized when [sqlite3_open()] is called if it has not be initialized 1213: ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1214: ** compile-time option, then the automatic calls to sqlite3_initialize() 1215: ** are omitted and the application must call sqlite3_initialize() directly 1216: ** prior to using any other SQLite interface. For maximum portability, 1217: ** it is recommended that applications always invoke sqlite3_initialize() 1218: ** directly prior to using any other SQLite interface. Future releases 1219: ** of SQLite may require this. In other words, the behavior exhibited 1220: ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1221: ** default behavior in some future release of SQLite. 1222: ** 1223: ** The sqlite3_os_init() routine does operating-system specific 1224: ** initialization of the SQLite library. The sqlite3_os_end() 1225: ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1226: ** performed by these routines include allocation or deallocation 1227: ** of static resources, initialization of global variables, 1228: ** setting up a default [sqlite3_vfs] module, or setting up 1229: ** a default configuration using [sqlite3_config()]. 1230: ** 1231: ** The application should never invoke either sqlite3_os_init() 1232: ** or sqlite3_os_end() directly. The application should only invoke 1233: ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1234: ** interface is called automatically by sqlite3_initialize() and 1235: ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1236: ** implementations for sqlite3_os_init() and sqlite3_os_end() 1237: ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1238: ** When [custom builds | built for other platforms] 1239: ** (using the [SQLITE_OS_OTHER=1] compile-time 1240: ** option) the application must supply a suitable implementation for 1241: ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1242: ** implementation of sqlite3_os_init() or sqlite3_os_end() 1243: ** must return [SQLITE_OK] on success and some other [error code] upon 1244: ** failure. 1245: */ 1246: SQLITE_API int sqlite3_initialize(void); 1247: SQLITE_API int sqlite3_shutdown(void); 1248: SQLITE_API int sqlite3_os_init(void); 1249: SQLITE_API int sqlite3_os_end(void); 1250: 1251: /* 1252: ** CAPI3REF: Configuring The SQLite Library 1253: ** 1254: ** The sqlite3_config() interface is used to make global configuration 1255: ** changes to SQLite in order to tune SQLite to the specific needs of 1256: ** the application. The default configuration is recommended for most 1257: ** applications and so this routine is usually not necessary. It is 1258: ** provided to support rare applications with unusual needs. 1259: ** 1260: ** The sqlite3_config() interface is not threadsafe. The application 1261: ** must insure that no other SQLite interfaces are invoked by other 1262: ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1263: ** may only be invoked prior to library initialization using 1264: ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1265: ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1266: ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1267: ** Note, however, that ^sqlite3_config() can be called as part of the 1268: ** implementation of an application-defined [sqlite3_os_init()]. 1269: ** 1270: ** The first argument to sqlite3_config() is an integer 1271: ** [configuration option] that determines 1272: ** what property of SQLite is to be configured. Subsequent arguments 1273: ** vary depending on the [configuration option] 1274: ** in the first argument. 1275: ** 1276: ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1277: ** ^If the option is unknown or SQLite is unable to set the option 1278: ** then this routine returns a non-zero [error code]. 1279: */ 1280: SQLITE_API int sqlite3_config(int, ...); 1281: 1282: /* 1283: ** CAPI3REF: Configure database connections 1284: ** 1285: ** The sqlite3_db_config() interface is used to make configuration 1286: ** changes to a [database connection]. The interface is similar to 1287: ** [sqlite3_config()] except that the changes apply to a single 1288: ** [database connection] (specified in the first argument). 1289: ** 1290: ** The second argument to sqlite3_db_config(D,V,...) is the 1291: ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1292: ** that indicates what aspect of the [database connection] is being configured. 1293: ** Subsequent arguments vary depending on the configuration verb. 1294: ** 1295: ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1296: ** the call is considered successful. 1297: */ 1298: SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1299: 1300: /* 1301: ** CAPI3REF: Memory Allocation Routines 1302: ** 1303: ** An instance of this object defines the interface between SQLite 1304: ** and low-level memory allocation routines. 1305: ** 1306: ** This object is used in only one place in the SQLite interface. 1307: ** A pointer to an instance of this object is the argument to 1308: ** [sqlite3_config()] when the configuration option is 1309: ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1310: ** By creating an instance of this object 1311: ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1312: ** during configuration, an application can specify an alternative 1313: ** memory allocation subsystem for SQLite to use for all of its 1314: ** dynamic memory needs. 1315: ** 1316: ** Note that SQLite comes with several [built-in memory allocators] 1317: ** that are perfectly adequate for the overwhelming majority of applications 1318: ** and that this object is only useful to a tiny minority of applications 1319: ** with specialized memory allocation requirements. This object is 1320: ** also used during testing of SQLite in order to specify an alternative 1321: ** memory allocator that simulates memory out-of-memory conditions in 1322: ** order to verify that SQLite recovers gracefully from such 1323: ** conditions. 1324: ** 1325: ** The xMalloc, xRealloc, and xFree methods must work like the 1326: ** malloc(), realloc() and free() functions from the standard C library. 1327: ** ^SQLite guarantees that the second argument to 1328: ** xRealloc is always a value returned by a prior call to xRoundup. 1329: ** 1330: ** xSize should return the allocated size of a memory allocation 1331: ** previously obtained from xMalloc or xRealloc. The allocated size 1332: ** is always at least as big as the requested size but may be larger. 1333: ** 1334: ** The xRoundup method returns what would be the allocated size of 1335: ** a memory allocation given a particular requested size. Most memory 1336: ** allocators round up memory allocations at least to the next multiple 1337: ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1338: ** Every memory allocation request coming in through [sqlite3_malloc()] 1339: ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1340: ** that causes the corresponding memory allocation to fail. 1341: ** 1342: ** The xInit method initializes the memory allocator. (For example, 1343: ** it might allocate any require mutexes or initialize internal data 1344: ** structures. The xShutdown method is invoked (indirectly) by 1345: ** [sqlite3_shutdown()] and should deallocate any resources acquired 1346: ** by xInit. The pAppData pointer is used as the only parameter to 1347: ** xInit and xShutdown. 1348: ** 1349: ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1350: ** the xInit method, so the xInit method need not be threadsafe. The 1351: ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1352: ** not need to be threadsafe either. For all other methods, SQLite 1353: ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1354: ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1355: ** it is by default) and so the methods are automatically serialized. 1356: ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1357: ** methods must be threadsafe or else make their own arrangements for 1358: ** serialization. 1359: ** 1360: ** SQLite will never invoke xInit() more than once without an intervening 1361: ** call to xShutdown(). 1362: */ 1363: typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1364: struct sqlite3_mem_methods { 1365: void *(*xMalloc)(int); /* Memory allocation function */ 1366: void (*xFree)(void*); /* Free a prior allocation */ 1367: void *(*xRealloc)(void*,int); /* Resize an allocation */ 1368: int (*xSize)(void*); /* Return the size of an allocation */ 1369: int (*xRoundup)(int); /* Round up request size to allocation size */ 1370: int (*xInit)(void*); /* Initialize the memory allocator */ 1371: void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1372: void *pAppData; /* Argument to xInit() and xShutdown() */ 1373: }; 1374: 1375: /* 1376: ** CAPI3REF: Configuration Options 1377: ** KEYWORDS: {configuration option} 1378: ** 1379: ** These constants are the available integer configuration options that 1380: ** can be passed as the first argument to the [sqlite3_config()] interface. 1381: ** 1382: ** New configuration options may be added in future releases of SQLite. 1383: ** Existing configuration options might be discontinued. Applications 1384: ** should check the return code from [sqlite3_config()] to make sure that 1385: ** the call worked. The [sqlite3_config()] interface will return a 1386: ** non-zero [error code] if a discontinued or unsupported configuration option 1387: ** is invoked. 1388: ** 1389: ** <dl> 1390: ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1391: ** <dd>There are no arguments to this option. ^This option sets the 1392: ** [threading mode] to Single-thread. In other words, it disables 1393: ** all mutexing and puts SQLite into a mode where it can only be used 1394: ** by a single thread. ^If SQLite is compiled with 1395: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1396: ** it is not possible to change the [threading mode] from its default 1397: ** value of Single-thread and so [sqlite3_config()] will return 1398: ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1399: ** configuration option.</dd> 1400: ** 1401: ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1402: ** <dd>There are no arguments to this option. ^This option sets the 1403: ** [threading mode] to Multi-thread. In other words, it disables 1404: ** mutexing on [database connection] and [prepared statement] objects. 1405: ** The application is responsible for serializing access to 1406: ** [database connections] and [prepared statements]. But other mutexes 1407: ** are enabled so that SQLite will be safe to use in a multi-threaded 1408: ** environment as long as no two threads attempt to use the same 1409: ** [database connection] at the same time. ^If SQLite is compiled with 1410: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1411: ** it is not possible to set the Multi-thread [threading mode] and 1412: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1413: ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1414: ** 1415: ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1416: ** <dd>There are no arguments to this option. ^This option sets the 1417: ** [threading mode] to Serialized. In other words, this option enables 1418: ** all mutexes including the recursive 1419: ** mutexes on [database connection] and [prepared statement] objects. 1420: ** In this mode (which is the default when SQLite is compiled with 1421: ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1422: ** to [database connections] and [prepared statements] so that the 1423: ** application is free to use the same [database connection] or the 1424: ** same [prepared statement] in different threads at the same time. 1425: ** ^If SQLite is compiled with 1426: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1427: ** it is not possible to set the Serialized [threading mode] and 1428: ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1429: ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1430: ** 1431: ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1432: ** <dd> ^(This option takes a single argument which is a pointer to an 1433: ** instance of the [sqlite3_mem_methods] structure. The argument specifies 1434: ** alternative low-level memory allocation routines to be used in place of 1435: ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1436: ** its own private copy of the content of the [sqlite3_mem_methods] structure 1437: ** before the [sqlite3_config()] call returns.</dd> 1438: ** 1439: ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1440: ** <dd> ^(This option takes a single argument which is a pointer to an 1441: ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1442: ** structure is filled with the currently defined memory allocation routines.)^ 1443: ** This option can be used to overload the default memory allocation 1444: ** routines with a wrapper that simulations memory allocation failure or 1445: ** tracks memory usage, for example. </dd> 1446: ** 1447: ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1448: ** <dd> ^This option takes single argument of type int, interpreted as a 1449: ** boolean, which enables or disables the collection of memory allocation 1450: ** statistics. ^(When memory allocation statistics are disabled, the 1451: ** following SQLite interfaces become non-operational: 1452: ** <ul> 1453: ** <li> [sqlite3_memory_used()] 1454: ** <li> [sqlite3_memory_highwater()] 1455: ** <li> [sqlite3_soft_heap_limit64()] 1456: ** <li> [sqlite3_status()] 1457: ** </ul>)^ 1458: ** ^Memory allocation statistics are enabled by default unless SQLite is 1459: ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1460: ** allocation statistics are disabled by default. 1461: ** </dd> 1462: ** 1463: ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1464: ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1465: ** scratch memory. There are three arguments: A pointer an 8-byte 1466: ** aligned memory buffer from which the scratch allocations will be 1467: ** drawn, the size of each scratch allocation (sz), 1468: ** and the maximum number of scratch allocations (N). The sz 1469: ** argument must be a multiple of 16. 1470: ** The first argument must be a pointer to an 8-byte aligned buffer 1471: ** of at least sz*N bytes of memory. 1472: ** ^SQLite will use no more than two scratch buffers per thread. So 1473: ** N should be set to twice the expected maximum number of threads. 1474: ** ^SQLite will never require a scratch buffer that is more than 6 1475: ** times the database page size. ^If SQLite needs needs additional 1476: ** scratch memory beyond what is provided by this configuration option, then 1477: ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1478: ** 1479: ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1480: ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1481: ** the database page cache with the default page cache implementation. 1482: ** This configuration should not be used if an application-define page 1483: ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1484: ** There are three arguments to this option: A pointer to 8-byte aligned 1485: ** memory, the size of each page buffer (sz), and the number of pages (N). 1486: ** The sz argument should be the size of the largest database page 1487: ** (a power of two between 512 and 32768) plus a little extra for each 1488: ** page header. ^The page header size is 20 to 40 bytes depending on 1489: ** the host architecture. ^It is harmless, apart from the wasted memory, 1490: ** to make sz a little too large. The first 1491: ** argument should point to an allocation of at least sz*N bytes of memory. 1492: ** ^SQLite will use the memory provided by the first argument to satisfy its 1493: ** memory needs for the first N pages that it adds to cache. ^If additional 1494: ** page cache memory is needed beyond what is provided by this option, then 1495: ** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1496: ** The pointer in the first argument must 1497: ** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1498: ** will be undefined.</dd> 1499: ** 1500: ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1501: ** <dd> ^This option specifies a static memory buffer that SQLite will use 1502: ** for all of its dynamic memory allocation needs beyond those provided 1503: ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1504: ** There are three arguments: An 8-byte aligned pointer to the memory, 1505: ** the number of bytes in the memory buffer, and the minimum allocation size. 1506: ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1507: ** to using its default memory allocator (the system malloc() implementation), 1508: ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1509: ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1510: ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1511: ** allocator is engaged to handle all of SQLites memory allocation needs. 1512: ** The first pointer (the memory pointer) must be aligned to an 8-byte 1513: ** boundary or subsequent behavior of SQLite will be undefined. 1514: ** The minimum allocation size is capped at 2**12. Reasonable values 1515: ** for the minimum allocation size are 2**5 through 2**8.</dd> 1516: ** 1517: ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1518: ** <dd> ^(This option takes a single argument which is a pointer to an 1519: ** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1520: ** alternative low-level mutex routines to be used in place 1521: ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1522: ** content of the [sqlite3_mutex_methods] structure before the call to 1523: ** [sqlite3_config()] returns. ^If SQLite is compiled with 1524: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1525: ** the entire mutexing subsystem is omitted from the build and hence calls to 1526: ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1527: ** return [SQLITE_ERROR].</dd> 1528: ** 1529: ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1530: ** <dd> ^(This option takes a single argument which is a pointer to an 1531: ** instance of the [sqlite3_mutex_methods] structure. The 1532: ** [sqlite3_mutex_methods] 1533: ** structure is filled with the currently defined mutex routines.)^ 1534: ** This option can be used to overload the default mutex allocation 1535: ** routines with a wrapper used to track mutex usage for performance 1536: ** profiling or testing, for example. ^If SQLite is compiled with 1537: ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1538: ** the entire mutexing subsystem is omitted from the build and hence calls to 1539: ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1540: ** return [SQLITE_ERROR].</dd> 1541: ** 1542: ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1543: ** <dd> ^(This option takes two arguments that determine the default 1544: ** memory allocation for the lookaside memory allocator on each 1545: ** [database connection]. The first argument is the 1546: ** size of each lookaside buffer slot and the second is the number of 1547: ** slots allocated to each database connection.)^ ^(This option sets the 1548: ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1549: ** verb to [sqlite3_db_config()] can be used to change the lookaside 1550: ** configuration on individual connections.)^ </dd> 1551: ** 1552: ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1553: ** <dd> ^(This option takes a single argument which is a pointer to 1554: ** an [sqlite3_pcache_methods2] object. This object specifies the interface 1555: ** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1556: ** object and uses it for page cache memory allocations.</dd> 1557: ** 1558: ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1559: ** <dd> ^(This option takes a single argument which is a pointer to an 1560: ** [sqlite3_pcache_methods2] object. SQLite copies of the current 1561: ** page cache implementation into that object.)^ </dd> 1562: ** 1563: ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1564: ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1565: ** function with a call signature of void(*)(void*,int,const char*), 1566: ** and a pointer to void. ^If the function pointer is not NULL, it is 1567: ** invoked by [sqlite3_log()] to process each logging event. ^If the 1568: ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1569: ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1570: ** passed through as the first parameter to the application-defined logger 1571: ** function whenever that function is invoked. ^The second parameter to 1572: ** the logger function is a copy of the first parameter to the corresponding 1573: ** [sqlite3_log()] call and is intended to be a [result code] or an 1574: ** [extended result code]. ^The third parameter passed to the logger is 1575: ** log message after formatting via [sqlite3_snprintf()]. 1576: ** The SQLite logging interface is not reentrant; the logger function 1577: ** supplied by the application must not invoke any SQLite interface. 1578: ** In a multi-threaded application, the application-defined logger 1579: ** function must be threadsafe. </dd> 1580: ** 1581: ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1582: ** <dd> This option takes a single argument of type int. If non-zero, then 1583: ** URI handling is globally enabled. If the parameter is zero, then URI handling 1584: ** is globally disabled. If URI handling is globally enabled, all filenames 1585: ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1586: ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1587: ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1588: ** connection is opened. If it is globally disabled, filenames are 1589: ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1590: ** database connection is opened. By default, URI handling is globally 1591: ** disabled. The default value may be changed by compiling with the 1592: ** [SQLITE_USE_URI] symbol defined. 1593: ** 1.3 ! misho 1594: ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN ! 1595: ** <dd> This option takes a single integer argument which is interpreted as ! 1596: ** a boolean in order to enable or disable the use of covering indices for ! 1597: ** full table scans in the query optimizer. The default setting is determined ! 1598: ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" ! 1599: ** if that compile-time option is omitted. ! 1600: ** The ability to disable the use of covering indices for full table scans ! 1601: ** is because some incorrectly coded legacy applications might malfunction ! 1602: ** malfunction when the optimization is enabled. Providing the ability to ! 1603: ** disable the optimization allows the older, buggy application code to work ! 1604: ** without change even with newer versions of SQLite. ! 1605: ** 1.2 misho 1606: ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1.3 ! misho 1607: ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1.2 misho 1608: ** <dd> These options are obsolete and should not be used by new code. 1609: ** They are retained for backwards compatibility but are now no-ops. 1610: ** </dl> 1.3 ! misho 1611: ** ! 1612: ** [[SQLITE_CONFIG_SQLLOG]] ! 1613: ** <dt>SQLITE_CONFIG_SQLLOG ! 1614: ** <dd>This option is only available if sqlite is compiled with the ! 1615: ** SQLITE_ENABLE_SQLLOG pre-processor macro defined. The first argument should ! 1616: ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). ! 1617: ** The second should be of type (void*). The callback is invoked by the library ! 1618: ** in three separate circumstances, identified by the value passed as the ! 1619: ** fourth parameter. If the fourth parameter is 0, then the database connection ! 1620: ** passed as the second argument has just been opened. The third argument ! 1621: ** points to a buffer containing the name of the main database file. If the ! 1622: ** fourth parameter is 1, then the SQL statement that the third parameter ! 1623: ** points to has just been executed. Or, if the fourth parameter is 2, then ! 1624: ** the connection being passed as the second parameter is being closed. The ! 1625: ** third parameter is passed NULL In this case. ! 1626: ** </dl> 1.2 misho 1627: */ 1628: #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1629: #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1630: #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1631: #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1632: #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1633: #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1634: #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1635: #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1636: #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1637: #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1638: #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1639: /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1640: #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1641: #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1642: #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1643: #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1644: #define SQLITE_CONFIG_URI 17 /* int */ 1645: #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1646: #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1.3 ! misho 1647: #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ ! 1648: #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1.2 misho 1649: 1650: /* 1651: ** CAPI3REF: Database Connection Configuration Options 1652: ** 1653: ** These constants are the available integer configuration options that 1654: ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1655: ** 1656: ** New configuration options may be added in future releases of SQLite. 1657: ** Existing configuration options might be discontinued. Applications 1658: ** should check the return code from [sqlite3_db_config()] to make sure that 1659: ** the call worked. ^The [sqlite3_db_config()] interface will return a 1660: ** non-zero [error code] if a discontinued or unsupported configuration option 1661: ** is invoked. 1662: ** 1663: ** <dl> 1664: ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1665: ** <dd> ^This option takes three additional arguments that determine the 1666: ** [lookaside memory allocator] configuration for the [database connection]. 1667: ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1668: ** pointer to a memory buffer to use for lookaside memory. 1669: ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1670: ** may be NULL in which case SQLite will allocate the 1671: ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1672: ** size of each lookaside buffer slot. ^The third argument is the number of 1673: ** slots. The size of the buffer in the first argument must be greater than 1674: ** or equal to the product of the second and third arguments. The buffer 1675: ** must be aligned to an 8-byte boundary. ^If the second argument to 1676: ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1677: ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1678: ** configuration for a database connection can only be changed when that 1679: ** connection is not currently using lookaside memory, or in other words 1680: ** when the "current value" returned by 1681: ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1682: ** Any attempt to change the lookaside memory configuration when lookaside 1683: ** memory is in use leaves the configuration unchanged and returns 1684: ** [SQLITE_BUSY].)^</dd> 1685: ** 1686: ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1687: ** <dd> ^This option is used to enable or disable the enforcement of 1688: ** [foreign key constraints]. There should be two additional arguments. 1689: ** The first argument is an integer which is 0 to disable FK enforcement, 1690: ** positive to enable FK enforcement or negative to leave FK enforcement 1691: ** unchanged. The second parameter is a pointer to an integer into which 1692: ** is written 0 or 1 to indicate whether FK enforcement is off or on 1693: ** following this call. The second parameter may be a NULL pointer, in 1694: ** which case the FK enforcement setting is not reported back. </dd> 1695: ** 1696: ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1697: ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1698: ** There should be two additional arguments. 1699: ** The first argument is an integer which is 0 to disable triggers, 1700: ** positive to enable triggers or negative to leave the setting unchanged. 1701: ** The second parameter is a pointer to an integer into which 1702: ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1703: ** following this call. The second parameter may be a NULL pointer, in 1704: ** which case the trigger setting is not reported back. </dd> 1705: ** 1706: ** </dl> 1707: */ 1708: #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1709: #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1710: #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1711: 1712: 1713: /* 1714: ** CAPI3REF: Enable Or Disable Extended Result Codes 1715: ** 1716: ** ^The sqlite3_extended_result_codes() routine enables or disables the 1717: ** [extended result codes] feature of SQLite. ^The extended result 1718: ** codes are disabled by default for historical compatibility. 1719: */ 1720: SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1721: 1722: /* 1723: ** CAPI3REF: Last Insert Rowid 1724: ** 1725: ** ^Each entry in an SQLite table has a unique 64-bit signed 1726: ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1727: ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1728: ** names are not also used by explicitly declared columns. ^If 1729: ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1730: ** is another alias for the rowid. 1731: ** 1732: ** ^This routine returns the [rowid] of the most recent 1733: ** successful [INSERT] into the database from the [database connection] 1734: ** in the first argument. ^As of SQLite version 3.7.7, this routines 1735: ** records the last insert rowid of both ordinary tables and [virtual tables]. 1736: ** ^If no successful [INSERT]s 1737: ** have ever occurred on that database connection, zero is returned. 1738: ** 1739: ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1740: ** method, then this routine will return the [rowid] of the inserted 1741: ** row as long as the trigger or virtual table method is running. 1742: ** But once the trigger or virtual table method ends, the value returned 1743: ** by this routine reverts to what it was before the trigger or virtual 1744: ** table method began.)^ 1745: ** 1746: ** ^An [INSERT] that fails due to a constraint violation is not a 1747: ** successful [INSERT] and does not change the value returned by this 1748: ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1749: ** and INSERT OR ABORT make no changes to the return value of this 1750: ** routine when their insertion fails. ^(When INSERT OR REPLACE 1751: ** encounters a constraint violation, it does not fail. The 1752: ** INSERT continues to completion after deleting rows that caused 1753: ** the constraint problem so INSERT OR REPLACE will always change 1754: ** the return value of this interface.)^ 1755: ** 1756: ** ^For the purposes of this routine, an [INSERT] is considered to 1757: ** be successful even if it is subsequently rolled back. 1758: ** 1759: ** This function is accessible to SQL statements via the 1760: ** [last_insert_rowid() SQL function]. 1761: ** 1762: ** If a separate thread performs a new [INSERT] on the same 1763: ** database connection while the [sqlite3_last_insert_rowid()] 1764: ** function is running and thus changes the last insert [rowid], 1765: ** then the value returned by [sqlite3_last_insert_rowid()] is 1766: ** unpredictable and might not equal either the old or the new 1767: ** last insert [rowid]. 1768: */ 1769: SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1770: 1771: /* 1772: ** CAPI3REF: Count The Number Of Rows Modified 1773: ** 1774: ** ^This function returns the number of database rows that were changed 1775: ** or inserted or deleted by the most recently completed SQL statement 1776: ** on the [database connection] specified by the first parameter. 1777: ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1778: ** or [DELETE] statement are counted. Auxiliary changes caused by 1779: ** triggers or [foreign key actions] are not counted.)^ Use the 1780: ** [sqlite3_total_changes()] function to find the total number of changes 1781: ** including changes caused by triggers and foreign key actions. 1782: ** 1783: ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1784: ** are not counted. Only real table changes are counted. 1785: ** 1786: ** ^(A "row change" is a change to a single row of a single table 1787: ** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1788: ** are changed as side effects of [REPLACE] constraint resolution, 1789: ** rollback, ABORT processing, [DROP TABLE], or by any other 1790: ** mechanisms do not count as direct row changes.)^ 1791: ** 1792: ** A "trigger context" is a scope of execution that begins and 1793: ** ends with the script of a [CREATE TRIGGER | trigger]. 1794: ** Most SQL statements are 1795: ** evaluated outside of any trigger. This is the "top level" 1796: ** trigger context. If a trigger fires from the top level, a 1797: ** new trigger context is entered for the duration of that one 1798: ** trigger. Subtriggers create subcontexts for their duration. 1799: ** 1800: ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1801: ** not create a new trigger context. 1802: ** 1803: ** ^This function returns the number of direct row changes in the 1804: ** most recent INSERT, UPDATE, or DELETE statement within the same 1805: ** trigger context. 1806: ** 1807: ** ^Thus, when called from the top level, this function returns the 1808: ** number of changes in the most recent INSERT, UPDATE, or DELETE 1809: ** that also occurred at the top level. ^(Within the body of a trigger, 1810: ** the sqlite3_changes() interface can be called to find the number of 1811: ** changes in the most recently completed INSERT, UPDATE, or DELETE 1812: ** statement within the body of the same trigger. 1813: ** However, the number returned does not include changes 1814: ** caused by subtriggers since those have their own context.)^ 1815: ** 1816: ** See also the [sqlite3_total_changes()] interface, the 1817: ** [count_changes pragma], and the [changes() SQL function]. 1818: ** 1819: ** If a separate thread makes changes on the same database connection 1820: ** while [sqlite3_changes()] is running then the value returned 1821: ** is unpredictable and not meaningful. 1822: */ 1823: SQLITE_API int sqlite3_changes(sqlite3*); 1824: 1825: /* 1826: ** CAPI3REF: Total Number Of Rows Modified 1827: ** 1828: ** ^This function returns the number of row changes caused by [INSERT], 1829: ** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1830: ** ^(The count returned by sqlite3_total_changes() includes all changes 1831: ** from all [CREATE TRIGGER | trigger] contexts and changes made by 1832: ** [foreign key actions]. However, 1833: ** the count does not include changes used to implement [REPLACE] constraints, 1834: ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1835: ** count does not include rows of views that fire an [INSTEAD OF trigger], 1836: ** though if the INSTEAD OF trigger makes changes of its own, those changes 1837: ** are counted.)^ 1838: ** ^The sqlite3_total_changes() function counts the changes as soon as 1839: ** the statement that makes them is completed (when the statement handle 1840: ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1841: ** 1842: ** See also the [sqlite3_changes()] interface, the 1843: ** [count_changes pragma], and the [total_changes() SQL function]. 1844: ** 1845: ** If a separate thread makes changes on the same database connection 1846: ** while [sqlite3_total_changes()] is running then the value 1847: ** returned is unpredictable and not meaningful. 1848: */ 1849: SQLITE_API int sqlite3_total_changes(sqlite3*); 1850: 1851: /* 1852: ** CAPI3REF: Interrupt A Long-Running Query 1853: ** 1854: ** ^This function causes any pending database operation to abort and 1855: ** return at its earliest opportunity. This routine is typically 1856: ** called in response to a user action such as pressing "Cancel" 1857: ** or Ctrl-C where the user wants a long query operation to halt 1858: ** immediately. 1859: ** 1860: ** ^It is safe to call this routine from a thread different from the 1861: ** thread that is currently running the database operation. But it 1862: ** is not safe to call this routine with a [database connection] that 1863: ** is closed or might close before sqlite3_interrupt() returns. 1864: ** 1865: ** ^If an SQL operation is very nearly finished at the time when 1866: ** sqlite3_interrupt() is called, then it might not have an opportunity 1867: ** to be interrupted and might continue to completion. 1868: ** 1869: ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1870: ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1871: ** that is inside an explicit transaction, then the entire transaction 1872: ** will be rolled back automatically. 1873: ** 1874: ** ^The sqlite3_interrupt(D) call is in effect until all currently running 1875: ** SQL statements on [database connection] D complete. ^Any new SQL statements 1876: ** that are started after the sqlite3_interrupt() call and before the 1877: ** running statements reaches zero are interrupted as if they had been 1878: ** running prior to the sqlite3_interrupt() call. ^New SQL statements 1879: ** that are started after the running statement count reaches zero are 1880: ** not effected by the sqlite3_interrupt(). 1881: ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1882: ** SQL statements is a no-op and has no effect on SQL statements 1883: ** that are started after the sqlite3_interrupt() call returns. 1884: ** 1885: ** If the database connection closes while [sqlite3_interrupt()] 1886: ** is running then bad things will likely happen. 1887: */ 1888: SQLITE_API void sqlite3_interrupt(sqlite3*); 1889: 1890: /* 1891: ** CAPI3REF: Determine If An SQL Statement Is Complete 1892: ** 1893: ** These routines are useful during command-line input to determine if the 1894: ** currently entered text seems to form a complete SQL statement or 1895: ** if additional input is needed before sending the text into 1896: ** SQLite for parsing. ^These routines return 1 if the input string 1897: ** appears to be a complete SQL statement. ^A statement is judged to be 1898: ** complete if it ends with a semicolon token and is not a prefix of a 1899: ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1900: ** string literals or quoted identifier names or comments are not 1901: ** independent tokens (they are part of the token in which they are 1902: ** embedded) and thus do not count as a statement terminator. ^Whitespace 1903: ** and comments that follow the final semicolon are ignored. 1904: ** 1905: ** ^These routines return 0 if the statement is incomplete. ^If a 1906: ** memory allocation fails, then SQLITE_NOMEM is returned. 1907: ** 1908: ** ^These routines do not parse the SQL statements thus 1909: ** will not detect syntactically incorrect SQL. 1910: ** 1911: ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 1912: ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 1913: ** automatically by sqlite3_complete16(). If that initialization fails, 1914: ** then the return value from sqlite3_complete16() will be non-zero 1915: ** regardless of whether or not the input SQL is complete.)^ 1916: ** 1917: ** The input to [sqlite3_complete()] must be a zero-terminated 1918: ** UTF-8 string. 1919: ** 1920: ** The input to [sqlite3_complete16()] must be a zero-terminated 1921: ** UTF-16 string in native byte order. 1922: */ 1923: SQLITE_API int sqlite3_complete(const char *sql); 1924: SQLITE_API int sqlite3_complete16(const void *sql); 1925: 1926: /* 1927: ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 1928: ** 1929: ** ^This routine sets a callback function that might be invoked whenever 1930: ** an attempt is made to open a database table that another thread 1931: ** or process has locked. 1932: ** 1933: ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 1934: ** is returned immediately upon encountering the lock. ^If the busy callback 1935: ** is not NULL, then the callback might be invoked with two arguments. 1936: ** 1937: ** ^The first argument to the busy handler is a copy of the void* pointer which 1938: ** is the third argument to sqlite3_busy_handler(). ^The second argument to 1939: ** the busy handler callback is the number of times that the busy handler has 1940: ** been invoked for this locking event. ^If the 1941: ** busy callback returns 0, then no additional attempts are made to 1942: ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1943: ** ^If the callback returns non-zero, then another attempt 1944: ** is made to open the database for reading and the cycle repeats. 1945: ** 1946: ** The presence of a busy handler does not guarantee that it will be invoked 1947: ** when there is lock contention. ^If SQLite determines that invoking the busy 1948: ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 1949: ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 1950: ** Consider a scenario where one process is holding a read lock that 1951: ** it is trying to promote to a reserved lock and 1952: ** a second process is holding a reserved lock that it is trying 1953: ** to promote to an exclusive lock. The first process cannot proceed 1954: ** because it is blocked by the second and the second process cannot 1955: ** proceed because it is blocked by the first. If both processes 1956: ** invoke the busy handlers, neither will make any progress. Therefore, 1957: ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1958: ** will induce the first process to release its read lock and allow 1959: ** the second process to proceed. 1960: ** 1961: ** ^The default busy callback is NULL. 1962: ** 1963: ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1964: ** when SQLite is in the middle of a large transaction where all the 1965: ** changes will not fit into the in-memory cache. SQLite will 1966: ** already hold a RESERVED lock on the database file, but it needs 1967: ** to promote this lock to EXCLUSIVE so that it can spill cache 1968: ** pages into the database file without harm to concurrent 1969: ** readers. ^If it is unable to promote the lock, then the in-memory 1970: ** cache will be left in an inconsistent state and so the error 1971: ** code is promoted from the relatively benign [SQLITE_BUSY] to 1972: ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 1973: ** forces an automatic rollback of the changes. See the 1974: ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1975: ** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1976: ** this is important. 1977: ** 1978: ** ^(There can only be a single busy handler defined for each 1979: ** [database connection]. Setting a new busy handler clears any 1980: ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 1981: ** will also set or clear the busy handler. 1982: ** 1983: ** The busy callback should not take any actions which modify the 1984: ** database connection that invoked the busy handler. Any such actions 1985: ** result in undefined behavior. 1986: ** 1987: ** A busy handler must not close the database connection 1988: ** or [prepared statement] that invoked the busy handler. 1989: */ 1990: SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1991: 1992: /* 1993: ** CAPI3REF: Set A Busy Timeout 1994: ** 1995: ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 1996: ** for a specified amount of time when a table is locked. ^The handler 1997: ** will sleep multiple times until at least "ms" milliseconds of sleeping 1998: ** have accumulated. ^After at least "ms" milliseconds of sleeping, 1999: ** the handler returns 0 which causes [sqlite3_step()] to return 2000: ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 2001: ** 2002: ** ^Calling this routine with an argument less than or equal to zero 2003: ** turns off all busy handlers. 2004: ** 2005: ** ^(There can only be a single busy handler for a particular 2006: ** [database connection] any any given moment. If another busy handler 2007: ** was defined (using [sqlite3_busy_handler()]) prior to calling 2008: ** this routine, that other busy handler is cleared.)^ 2009: */ 2010: SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2011: 2012: /* 2013: ** CAPI3REF: Convenience Routines For Running Queries 2014: ** 2015: ** This is a legacy interface that is preserved for backwards compatibility. 2016: ** Use of this interface is not recommended. 2017: ** 2018: ** Definition: A <b>result table</b> is memory data structure created by the 2019: ** [sqlite3_get_table()] interface. A result table records the 2020: ** complete query results from one or more queries. 2021: ** 2022: ** The table conceptually has a number of rows and columns. But 2023: ** these numbers are not part of the result table itself. These 2024: ** numbers are obtained separately. Let N be the number of rows 2025: ** and M be the number of columns. 2026: ** 2027: ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2028: ** There are (N+1)*M elements in the array. The first M pointers point 2029: ** to zero-terminated strings that contain the names of the columns. 2030: ** The remaining entries all point to query results. NULL values result 2031: ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2032: ** string representation as returned by [sqlite3_column_text()]. 2033: ** 2034: ** A result table might consist of one or more memory allocations. 2035: ** It is not safe to pass a result table directly to [sqlite3_free()]. 2036: ** A result table should be deallocated using [sqlite3_free_table()]. 2037: ** 2038: ** ^(As an example of the result table format, suppose a query result 2039: ** is as follows: 2040: ** 2041: ** <blockquote><pre> 2042: ** Name | Age 2043: ** ----------------------- 2044: ** Alice | 43 2045: ** Bob | 28 2046: ** Cindy | 21 2047: ** </pre></blockquote> 2048: ** 2049: ** There are two column (M==2) and three rows (N==3). Thus the 2050: ** result table has 8 entries. Suppose the result table is stored 2051: ** in an array names azResult. Then azResult holds this content: 2052: ** 2053: ** <blockquote><pre> 2054: ** azResult[0] = "Name"; 2055: ** azResult[1] = "Age"; 2056: ** azResult[2] = "Alice"; 2057: ** azResult[3] = "43"; 2058: ** azResult[4] = "Bob"; 2059: ** azResult[5] = "28"; 2060: ** azResult[6] = "Cindy"; 2061: ** azResult[7] = "21"; 2062: ** </pre></blockquote>)^ 2063: ** 2064: ** ^The sqlite3_get_table() function evaluates one or more 2065: ** semicolon-separated SQL statements in the zero-terminated UTF-8 2066: ** string of its 2nd parameter and returns a result table to the 2067: ** pointer given in its 3rd parameter. 2068: ** 2069: ** After the application has finished with the result from sqlite3_get_table(), 2070: ** it must pass the result table pointer to sqlite3_free_table() in order to 2071: ** release the memory that was malloced. Because of the way the 2072: ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2073: ** function must not try to call [sqlite3_free()] directly. Only 2074: ** [sqlite3_free_table()] is able to release the memory properly and safely. 2075: ** 2076: ** The sqlite3_get_table() interface is implemented as a wrapper around 2077: ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2078: ** to any internal data structures of SQLite. It uses only the public 2079: ** interface defined here. As a consequence, errors that occur in the 2080: ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2081: ** reflected in subsequent calls to [sqlite3_errcode()] or 2082: ** [sqlite3_errmsg()]. 2083: */ 2084: SQLITE_API int sqlite3_get_table( 2085: sqlite3 *db, /* An open database */ 2086: const char *zSql, /* SQL to be evaluated */ 2087: char ***pazResult, /* Results of the query */ 2088: int *pnRow, /* Number of result rows written here */ 2089: int *pnColumn, /* Number of result columns written here */ 2090: char **pzErrmsg /* Error msg written here */ 2091: ); 2092: SQLITE_API void sqlite3_free_table(char **result); 2093: 2094: /* 2095: ** CAPI3REF: Formatted String Printing Functions 2096: ** 2097: ** These routines are work-alikes of the "printf()" family of functions 2098: ** from the standard C library. 2099: ** 2100: ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2101: ** results into memory obtained from [sqlite3_malloc()]. 2102: ** The strings returned by these two routines should be 2103: ** released by [sqlite3_free()]. ^Both routines return a 2104: ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2105: ** memory to hold the resulting string. 2106: ** 2107: ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2108: ** the standard C library. The result is written into the 2109: ** buffer supplied as the second parameter whose size is given by 2110: ** the first parameter. Note that the order of the 2111: ** first two parameters is reversed from snprintf().)^ This is an 2112: ** historical accident that cannot be fixed without breaking 2113: ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2114: ** returns a pointer to its buffer instead of the number of 2115: ** characters actually written into the buffer.)^ We admit that 2116: ** the number of characters written would be a more useful return 2117: ** value but we cannot change the implementation of sqlite3_snprintf() 2118: ** now without breaking compatibility. 2119: ** 2120: ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2121: ** guarantees that the buffer is always zero-terminated. ^The first 2122: ** parameter "n" is the total size of the buffer, including space for 2123: ** the zero terminator. So the longest string that can be completely 2124: ** written will be n-1 characters. 2125: ** 2126: ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2127: ** 2128: ** These routines all implement some additional formatting 2129: ** options that are useful for constructing SQL statements. 2130: ** All of the usual printf() formatting options apply. In addition, there 2131: ** is are "%q", "%Q", and "%z" options. 2132: ** 2133: ** ^(The %q option works like %s in that it substitutes a nul-terminated 2134: ** string from the argument list. But %q also doubles every '\'' character. 2135: ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2136: ** character it escapes that character and allows it to be inserted into 2137: ** the string. 2138: ** 2139: ** For example, assume the string variable zText contains text as follows: 2140: ** 2141: ** <blockquote><pre> 2142: ** char *zText = "It's a happy day!"; 2143: ** </pre></blockquote> 2144: ** 2145: ** One can use this text in an SQL statement as follows: 2146: ** 2147: ** <blockquote><pre> 2148: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2149: ** sqlite3_exec(db, zSQL, 0, 0, 0); 2150: ** sqlite3_free(zSQL); 2151: ** </pre></blockquote> 2152: ** 2153: ** Because the %q format string is used, the '\'' character in zText 2154: ** is escaped and the SQL generated is as follows: 2155: ** 2156: ** <blockquote><pre> 2157: ** INSERT INTO table1 VALUES('It''s a happy day!') 2158: ** </pre></blockquote> 2159: ** 2160: ** This is correct. Had we used %s instead of %q, the generated SQL 2161: ** would have looked like this: 2162: ** 2163: ** <blockquote><pre> 2164: ** INSERT INTO table1 VALUES('It's a happy day!'); 2165: ** </pre></blockquote> 2166: ** 2167: ** This second example is an SQL syntax error. As a general rule you should 2168: ** always use %q instead of %s when inserting text into a string literal. 2169: ** 2170: ** ^(The %Q option works like %q except it also adds single quotes around 2171: ** the outside of the total string. Additionally, if the parameter in the 2172: ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2173: ** single quotes).)^ So, for example, one could say: 2174: ** 2175: ** <blockquote><pre> 2176: ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2177: ** sqlite3_exec(db, zSQL, 0, 0, 0); 2178: ** sqlite3_free(zSQL); 2179: ** </pre></blockquote> 2180: ** 2181: ** The code above will render a correct SQL statement in the zSQL 2182: ** variable even if the zText variable is a NULL pointer. 2183: ** 2184: ** ^(The "%z" formatting option works like "%s" but with the 2185: ** addition that after the string has been read and copied into 2186: ** the result, [sqlite3_free()] is called on the input string.)^ 2187: */ 2188: SQLITE_API char *sqlite3_mprintf(const char*,...); 2189: SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2190: SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2191: SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2192: 2193: /* 2194: ** CAPI3REF: Memory Allocation Subsystem 2195: ** 2196: ** The SQLite core uses these three routines for all of its own 2197: ** internal memory allocation needs. "Core" in the previous sentence 2198: ** does not include operating-system specific VFS implementation. The 2199: ** Windows VFS uses native malloc() and free() for some operations. 2200: ** 2201: ** ^The sqlite3_malloc() routine returns a pointer to a block 2202: ** of memory at least N bytes in length, where N is the parameter. 2203: ** ^If sqlite3_malloc() is unable to obtain sufficient free 2204: ** memory, it returns a NULL pointer. ^If the parameter N to 2205: ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2206: ** a NULL pointer. 2207: ** 2208: ** ^Calling sqlite3_free() with a pointer previously returned 2209: ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2210: ** that it might be reused. ^The sqlite3_free() routine is 2211: ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2212: ** to sqlite3_free() is harmless. After being freed, memory 2213: ** should neither be read nor written. Even reading previously freed 2214: ** memory might result in a segmentation fault or other severe error. 2215: ** Memory corruption, a segmentation fault, or other severe error 2216: ** might result if sqlite3_free() is called with a non-NULL pointer that 2217: ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2218: ** 2219: ** ^(The sqlite3_realloc() interface attempts to resize a 2220: ** prior memory allocation to be at least N bytes, where N is the 2221: ** second parameter. The memory allocation to be resized is the first 2222: ** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2223: ** is a NULL pointer then its behavior is identical to calling 2224: ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2225: ** ^If the second parameter to sqlite3_realloc() is zero or 2226: ** negative then the behavior is exactly the same as calling 2227: ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2228: ** ^sqlite3_realloc() returns a pointer to a memory allocation 2229: ** of at least N bytes in size or NULL if sufficient memory is unavailable. 2230: ** ^If M is the size of the prior allocation, then min(N,M) bytes 2231: ** of the prior allocation are copied into the beginning of buffer returned 2232: ** by sqlite3_realloc() and the prior allocation is freed. 2233: ** ^If sqlite3_realloc() returns NULL, then the prior allocation 2234: ** is not freed. 2235: ** 2236: ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2237: ** is always aligned to at least an 8 byte boundary, or to a 2238: ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2239: ** option is used. 2240: ** 2241: ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2242: ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2243: ** implementation of these routines to be omitted. That capability 2244: ** is no longer provided. Only built-in memory allocators can be used. 2245: ** 1.3 ! misho 2246: ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 1.2 misho 2247: ** the system malloc() and free() directly when converting 2248: ** filenames between the UTF-8 encoding used by SQLite 2249: ** and whatever filename encoding is used by the particular Windows 1.3 ! misho 2250: ** installation. Memory allocation errors were detected, but ! 2251: ** they were reported back as [SQLITE_CANTOPEN] or 1.2 misho 2252: ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2253: ** 2254: ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2255: ** must be either NULL or else pointers obtained from a prior 2256: ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2257: ** not yet been released. 2258: ** 2259: ** The application must not read or write any part of 2260: ** a block of memory after it has been released using 2261: ** [sqlite3_free()] or [sqlite3_realloc()]. 2262: */ 2263: SQLITE_API void *sqlite3_malloc(int); 2264: SQLITE_API void *sqlite3_realloc(void*, int); 2265: SQLITE_API void sqlite3_free(void*); 2266: 2267: /* 2268: ** CAPI3REF: Memory Allocator Statistics 2269: ** 2270: ** SQLite provides these two interfaces for reporting on the status 2271: ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2272: ** routines, which form the built-in memory allocation subsystem. 2273: ** 2274: ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2275: ** of memory currently outstanding (malloced but not freed). 2276: ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2277: ** value of [sqlite3_memory_used()] since the high-water mark 2278: ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2279: ** [sqlite3_memory_highwater()] include any overhead 2280: ** added by SQLite in its implementation of [sqlite3_malloc()], 2281: ** but not overhead added by the any underlying system library 2282: ** routines that [sqlite3_malloc()] may call. 2283: ** 2284: ** ^The memory high-water mark is reset to the current value of 2285: ** [sqlite3_memory_used()] if and only if the parameter to 2286: ** [sqlite3_memory_highwater()] is true. ^The value returned 2287: ** by [sqlite3_memory_highwater(1)] is the high-water mark 2288: ** prior to the reset. 2289: */ 2290: SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2291: SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2292: 2293: /* 2294: ** CAPI3REF: Pseudo-Random Number Generator 2295: ** 2296: ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2297: ** select random [ROWID | ROWIDs] when inserting new records into a table that 2298: ** already uses the largest possible [ROWID]. The PRNG is also used for 2299: ** the build-in random() and randomblob() SQL functions. This interface allows 2300: ** applications to access the same PRNG for other purposes. 2301: ** 2302: ** ^A call to this routine stores N bytes of randomness into buffer P. 2303: ** 2304: ** ^The first time this routine is invoked (either internally or by 2305: ** the application) the PRNG is seeded using randomness obtained 2306: ** from the xRandomness method of the default [sqlite3_vfs] object. 2307: ** ^On all subsequent invocations, the pseudo-randomness is generated 2308: ** internally and without recourse to the [sqlite3_vfs] xRandomness 2309: ** method. 2310: */ 2311: SQLITE_API void sqlite3_randomness(int N, void *P); 2312: 2313: /* 2314: ** CAPI3REF: Compile-Time Authorization Callbacks 2315: ** 2316: ** ^This routine registers an authorizer callback with a particular 2317: ** [database connection], supplied in the first argument. 2318: ** ^The authorizer callback is invoked as SQL statements are being compiled 2319: ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2320: ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2321: ** points during the compilation process, as logic is being created 2322: ** to perform various actions, the authorizer callback is invoked to 2323: ** see if those actions are allowed. ^The authorizer callback should 2324: ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2325: ** specific action but allow the SQL statement to continue to be 2326: ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2327: ** rejected with an error. ^If the authorizer callback returns 2328: ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2329: ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2330: ** the authorizer will fail with an error message. 2331: ** 2332: ** When the callback returns [SQLITE_OK], that means the operation 2333: ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2334: ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2335: ** authorizer will fail with an error message explaining that 2336: ** access is denied. 2337: ** 2338: ** ^The first parameter to the authorizer callback is a copy of the third 2339: ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2340: ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2341: ** the particular action to be authorized. ^The third through sixth parameters 2342: ** to the callback are zero-terminated strings that contain additional 2343: ** details about the action to be authorized. 2344: ** 2345: ** ^If the action code is [SQLITE_READ] 2346: ** and the callback returns [SQLITE_IGNORE] then the 2347: ** [prepared statement] statement is constructed to substitute 2348: ** a NULL value in place of the table column that would have 2349: ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2350: ** return can be used to deny an untrusted user access to individual 2351: ** columns of a table. 2352: ** ^If the action code is [SQLITE_DELETE] and the callback returns 2353: ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2354: ** [truncate optimization] is disabled and all rows are deleted individually. 2355: ** 2356: ** An authorizer is used when [sqlite3_prepare | preparing] 2357: ** SQL statements from an untrusted source, to ensure that the SQL statements 2358: ** do not try to access data they are not allowed to see, or that they do not 2359: ** try to execute malicious statements that damage the database. For 2360: ** example, an application may allow a user to enter arbitrary 2361: ** SQL queries for evaluation by a database. But the application does 2362: ** not want the user to be able to make arbitrary changes to the 2363: ** database. An authorizer could then be put in place while the 2364: ** user-entered SQL is being [sqlite3_prepare | prepared] that 2365: ** disallows everything except [SELECT] statements. 2366: ** 2367: ** Applications that need to process SQL from untrusted sources 2368: ** might also consider lowering resource limits using [sqlite3_limit()] 2369: ** and limiting database size using the [max_page_count] [PRAGMA] 2370: ** in addition to using an authorizer. 2371: ** 2372: ** ^(Only a single authorizer can be in place on a database connection 2373: ** at a time. Each call to sqlite3_set_authorizer overrides the 2374: ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2375: ** The authorizer is disabled by default. 2376: ** 2377: ** The authorizer callback must not do anything that will modify 2378: ** the database connection that invoked the authorizer callback. 2379: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2380: ** database connections for the meaning of "modify" in this paragraph. 2381: ** 2382: ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2383: ** statement might be re-prepared during [sqlite3_step()] due to a 2384: ** schema change. Hence, the application should ensure that the 2385: ** correct authorizer callback remains in place during the [sqlite3_step()]. 2386: ** 2387: ** ^Note that the authorizer callback is invoked only during 2388: ** [sqlite3_prepare()] or its variants. Authorization is not 2389: ** performed during statement evaluation in [sqlite3_step()], unless 2390: ** as stated in the previous paragraph, sqlite3_step() invokes 2391: ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2392: */ 2393: SQLITE_API int sqlite3_set_authorizer( 2394: sqlite3*, 2395: int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2396: void *pUserData 2397: ); 2398: 2399: /* 2400: ** CAPI3REF: Authorizer Return Codes 2401: ** 2402: ** The [sqlite3_set_authorizer | authorizer callback function] must 2403: ** return either [SQLITE_OK] or one of these two constants in order 2404: ** to signal SQLite whether or not the action is permitted. See the 2405: ** [sqlite3_set_authorizer | authorizer documentation] for additional 2406: ** information. 2407: ** 2408: ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2409: ** from the [sqlite3_vtab_on_conflict()] interface. 2410: */ 2411: #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2412: #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2413: 2414: /* 2415: ** CAPI3REF: Authorizer Action Codes 2416: ** 2417: ** The [sqlite3_set_authorizer()] interface registers a callback function 2418: ** that is invoked to authorize certain SQL statement actions. The 2419: ** second parameter to the callback is an integer code that specifies 2420: ** what action is being authorized. These are the integer action codes that 2421: ** the authorizer callback may be passed. 2422: ** 2423: ** These action code values signify what kind of operation is to be 2424: ** authorized. The 3rd and 4th parameters to the authorization 2425: ** callback function will be parameters or NULL depending on which of these 2426: ** codes is used as the second parameter. ^(The 5th parameter to the 2427: ** authorizer callback is the name of the database ("main", "temp", 2428: ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2429: ** is the name of the inner-most trigger or view that is responsible for 2430: ** the access attempt or NULL if this access attempt is directly from 2431: ** top-level SQL code. 2432: */ 2433: /******************************************* 3rd ************ 4th ***********/ 2434: #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2435: #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2436: #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2437: #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2438: #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2439: #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2440: #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2441: #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2442: #define SQLITE_DELETE 9 /* Table Name NULL */ 2443: #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2444: #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2445: #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2446: #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2447: #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2448: #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2449: #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2450: #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2451: #define SQLITE_INSERT 18 /* Table Name NULL */ 2452: #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2453: #define SQLITE_READ 20 /* Table Name Column Name */ 2454: #define SQLITE_SELECT 21 /* NULL NULL */ 2455: #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2456: #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2457: #define SQLITE_ATTACH 24 /* Filename NULL */ 2458: #define SQLITE_DETACH 25 /* Database Name NULL */ 2459: #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2460: #define SQLITE_REINDEX 27 /* Index Name NULL */ 2461: #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2462: #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2463: #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2464: #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2465: #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2466: #define SQLITE_COPY 0 /* No longer used */ 2467: 2468: /* 2469: ** CAPI3REF: Tracing And Profiling Functions 2470: ** 2471: ** These routines register callback functions that can be used for 2472: ** tracing and profiling the execution of SQL statements. 2473: ** 2474: ** ^The callback function registered by sqlite3_trace() is invoked at 2475: ** various times when an SQL statement is being run by [sqlite3_step()]. 2476: ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2477: ** SQL statement text as the statement first begins executing. 2478: ** ^(Additional sqlite3_trace() callbacks might occur 2479: ** as each triggered subprogram is entered. The callbacks for triggers 2480: ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2481: ** 2482: ** ^The callback function registered by sqlite3_profile() is invoked 2483: ** as each SQL statement finishes. ^The profile callback contains 2484: ** the original statement text and an estimate of wall-clock time 2485: ** of how long that statement took to run. ^The profile callback 2486: ** time is in units of nanoseconds, however the current implementation 2487: ** is only capable of millisecond resolution so the six least significant 2488: ** digits in the time are meaningless. Future versions of SQLite 2489: ** might provide greater resolution on the profiler callback. The 2490: ** sqlite3_profile() function is considered experimental and is 2491: ** subject to change in future versions of SQLite. 2492: */ 2493: SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2494: SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2495: void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2496: 2497: /* 2498: ** CAPI3REF: Query Progress Callbacks 2499: ** 2500: ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2501: ** function X to be invoked periodically during long running calls to 2502: ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2503: ** database connection D. An example use for this 2504: ** interface is to keep a GUI updated during a large query. 2505: ** 2506: ** ^The parameter P is passed through as the only parameter to the 2507: ** callback function X. ^The parameter N is the number of 2508: ** [virtual machine instructions] that are evaluated between successive 2509: ** invocations of the callback X. 2510: ** 2511: ** ^Only a single progress handler may be defined at one time per 2512: ** [database connection]; setting a new progress handler cancels the 2513: ** old one. ^Setting parameter X to NULL disables the progress handler. 2514: ** ^The progress handler is also disabled by setting N to a value less 2515: ** than 1. 2516: ** 2517: ** ^If the progress callback returns non-zero, the operation is 2518: ** interrupted. This feature can be used to implement a 2519: ** "Cancel" button on a GUI progress dialog box. 2520: ** 2521: ** The progress handler callback must not do anything that will modify 2522: ** the database connection that invoked the progress handler. 2523: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2524: ** database connections for the meaning of "modify" in this paragraph. 2525: ** 2526: */ 2527: SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2528: 2529: /* 2530: ** CAPI3REF: Opening A New Database Connection 2531: ** 2532: ** ^These routines open an SQLite database file as specified by the 2533: ** filename argument. ^The filename argument is interpreted as UTF-8 for 2534: ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2535: ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2536: ** returned in *ppDb, even if an error occurs. The only exception is that 2537: ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2538: ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2539: ** object.)^ ^(If the database is opened (and/or created) successfully, then 2540: ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2541: ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2542: ** an English language description of the error following a failure of any 2543: ** of the sqlite3_open() routines. 2544: ** 2545: ** ^The default encoding for the database will be UTF-8 if 2546: ** sqlite3_open() or sqlite3_open_v2() is called and 2547: ** UTF-16 in the native byte order if sqlite3_open16() is used. 2548: ** 2549: ** Whether or not an error occurs when it is opened, resources 2550: ** associated with the [database connection] handle should be released by 2551: ** passing it to [sqlite3_close()] when it is no longer required. 2552: ** 2553: ** The sqlite3_open_v2() interface works like sqlite3_open() 2554: ** except that it accepts two additional parameters for additional control 2555: ** over the new database connection. ^(The flags parameter to 2556: ** sqlite3_open_v2() can take one of 2557: ** the following three values, optionally combined with the 2558: ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2559: ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2560: ** 2561: ** <dl> 2562: ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2563: ** <dd>The database is opened in read-only mode. If the database does not 2564: ** already exist, an error is returned.</dd>)^ 2565: ** 2566: ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2567: ** <dd>The database is opened for reading and writing if possible, or reading 2568: ** only if the file is write protected by the operating system. In either 2569: ** case the database must already exist, otherwise an error is returned.</dd>)^ 2570: ** 2571: ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2572: ** <dd>The database is opened for reading and writing, and is created if 2573: ** it does not already exist. This is the behavior that is always used for 2574: ** sqlite3_open() and sqlite3_open16().</dd>)^ 2575: ** </dl> 2576: ** 2577: ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2578: ** combinations shown above optionally combined with other 2579: ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2580: ** then the behavior is undefined. 2581: ** 2582: ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2583: ** opens in the multi-thread [threading mode] as long as the single-thread 2584: ** mode has not been set at compile-time or start-time. ^If the 2585: ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2586: ** in the serialized [threading mode] unless single-thread was 2587: ** previously selected at compile-time or start-time. 2588: ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2589: ** eligible to use [shared cache mode], regardless of whether or not shared 2590: ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2591: ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2592: ** participate in [shared cache mode] even if it is enabled. 2593: ** 2594: ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2595: ** [sqlite3_vfs] object that defines the operating system interface that 2596: ** the new database connection should use. ^If the fourth parameter is 2597: ** a NULL pointer then the default [sqlite3_vfs] object is used. 2598: ** 2599: ** ^If the filename is ":memory:", then a private, temporary in-memory database 2600: ** is created for the connection. ^This in-memory database will vanish when 2601: ** the database connection is closed. Future versions of SQLite might 2602: ** make use of additional special filenames that begin with the ":" character. 2603: ** It is recommended that when a database filename actually does begin with 2604: ** a ":" character you should prefix the filename with a pathname such as 2605: ** "./" to avoid ambiguity. 2606: ** 2607: ** ^If the filename is an empty string, then a private, temporary 2608: ** on-disk database will be created. ^This private database will be 2609: ** automatically deleted as soon as the database connection is closed. 2610: ** 2611: ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2612: ** 2613: ** ^If [URI filename] interpretation is enabled, and the filename argument 2614: ** begins with "file:", then the filename is interpreted as a URI. ^URI 2615: ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2616: ** set in the fourth argument to sqlite3_open_v2(), or if it has 2617: ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2618: ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2619: ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2620: ** by default, but future releases of SQLite might enable URI filename 2621: ** interpretation by default. See "[URI filenames]" for additional 2622: ** information. 2623: ** 2624: ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2625: ** authority, then it must be either an empty string or the string 2626: ** "localhost". ^If the authority is not an empty string or "localhost", an 2627: ** error is returned to the caller. ^The fragment component of a URI, if 2628: ** present, is ignored. 2629: ** 2630: ** ^SQLite uses the path component of the URI as the name of the disk file 2631: ** which contains the database. ^If the path begins with a '/' character, 2632: ** then it is interpreted as an absolute path. ^If the path does not begin 2633: ** with a '/' (meaning that the authority section is omitted from the URI) 2634: ** then the path is interpreted as a relative path. 2635: ** ^On windows, the first component of an absolute path 2636: ** is a drive specification (e.g. "C:"). 2637: ** 2638: ** [[core URI query parameters]] 2639: ** The query component of a URI may contain parameters that are interpreted 2640: ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2641: ** SQLite interprets the following three query parameters: 2642: ** 2643: ** <ul> 2644: ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2645: ** a VFS object that provides the operating system interface that should 2646: ** be used to access the database file on disk. ^If this option is set to 2647: ** an empty string the default VFS object is used. ^Specifying an unknown 2648: ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2649: ** present, then the VFS specified by the option takes precedence over 2650: ** the value passed as the fourth parameter to sqlite3_open_v2(). 2651: ** 1.3 ! misho 2652: ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", ! 2653: ** "rwc", or "memory". Attempting to set it to any other value is ! 2654: ** an error)^. 1.2 misho 2655: ** ^If "ro" is specified, then the database is opened for read-only 2656: ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 1.3 ! misho 2657: ** third argument to sqlite3_open_v2(). ^If the mode option is set to 1.2 misho 2658: ** "rw", then the database is opened for read-write (but not create) 2659: ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2660: ** been set. ^Value "rwc" is equivalent to setting both 1.3 ! misho 2661: ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is ! 2662: ** set to "memory" then a pure [in-memory database] that never reads ! 2663: ** or writes from disk is used. ^It is an error to specify a value for ! 2664: ** the mode parameter that is less restrictive than that specified by ! 2665: ** the flags passed in the third parameter to sqlite3_open_v2(). 1.2 misho 2666: ** 2667: ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2668: ** "private". ^Setting it to "shared" is equivalent to setting the 2669: ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2670: ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2671: ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2672: ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2673: ** a URI filename, its value overrides any behaviour requested by setting 2674: ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2675: ** </ul> 2676: ** 2677: ** ^Specifying an unknown parameter in the query component of a URI is not an 2678: ** error. Future versions of SQLite might understand additional query 2679: ** parameters. See "[query parameters with special meaning to SQLite]" for 2680: ** additional information. 2681: ** 2682: ** [[URI filename examples]] <h3>URI filename examples</h3> 2683: ** 2684: ** <table border="1" align=center cellpadding=5> 2685: ** <tr><th> URI filenames <th> Results 2686: ** <tr><td> file:data.db <td> 2687: ** Open the file "data.db" in the current directory. 2688: ** <tr><td> file:/home/fred/data.db<br> 2689: ** file:///home/fred/data.db <br> 2690: ** file://localhost/home/fred/data.db <br> <td> 2691: ** Open the database file "/home/fred/data.db". 2692: ** <tr><td> file://darkstar/home/fred/data.db <td> 2693: ** An error. "darkstar" is not a recognized authority. 2694: ** <tr><td style="white-space:nowrap"> 2695: ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2696: ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2697: ** C:. Note that the %20 escaping in this example is not strictly 2698: ** necessary - space characters can be used literally 2699: ** in URI filenames. 2700: ** <tr><td> file:data.db?mode=ro&cache=private <td> 2701: ** Open file "data.db" in the current directory for read-only access. 2702: ** Regardless of whether or not shared-cache mode is enabled by 2703: ** default, use a private cache. 2704: ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2705: ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2706: ** <tr><td> file:data.db?mode=readonly <td> 2707: ** An error. "readonly" is not a valid option for the "mode" parameter. 2708: ** </table> 2709: ** 2710: ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2711: ** query components of a URI. A hexadecimal escape sequence consists of a 2712: ** percent sign - "%" - followed by exactly two hexadecimal digits 2713: ** specifying an octet value. ^Before the path or query components of a 2714: ** URI filename are interpreted, they are encoded using UTF-8 and all 2715: ** hexadecimal escape sequences replaced by a single byte containing the 2716: ** corresponding octet. If this process generates an invalid UTF-8 encoding, 2717: ** the results are undefined. 2718: ** 2719: ** <b>Note to Windows users:</b> The encoding used for the filename argument 2720: ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2721: ** codepage is currently defined. Filenames containing international 2722: ** characters must be converted to UTF-8 prior to passing them into 2723: ** sqlite3_open() or sqlite3_open_v2(). 1.3 ! misho 2724: ** ! 2725: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set ! 2726: ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various ! 2727: ** features that require the use of temporary files may fail. ! 2728: ** ! 2729: ** See also: [sqlite3_temp_directory] 1.2 misho 2730: */ 2731: SQLITE_API int sqlite3_open( 2732: const char *filename, /* Database filename (UTF-8) */ 2733: sqlite3 **ppDb /* OUT: SQLite db handle */ 2734: ); 2735: SQLITE_API int sqlite3_open16( 2736: const void *filename, /* Database filename (UTF-16) */ 2737: sqlite3 **ppDb /* OUT: SQLite db handle */ 2738: ); 2739: SQLITE_API int sqlite3_open_v2( 2740: const char *filename, /* Database filename (UTF-8) */ 2741: sqlite3 **ppDb, /* OUT: SQLite db handle */ 2742: int flags, /* Flags */ 2743: const char *zVfs /* Name of VFS module to use */ 2744: ); 2745: 2746: /* 2747: ** CAPI3REF: Obtain Values For URI Parameters 2748: ** 2749: ** These are utility routines, useful to VFS implementations, that check 2750: ** to see if a database file was a URI that contained a specific query 2751: ** parameter, and if so obtains the value of that query parameter. 2752: ** 2753: ** If F is the database filename pointer passed into the xOpen() method of 2754: ** a VFS implementation when the flags parameter to xOpen() has one or 2755: ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2756: ** P is the name of the query parameter, then 2757: ** sqlite3_uri_parameter(F,P) returns the value of the P 2758: ** parameter if it exists or a NULL pointer if P does not appear as a 2759: ** query parameter on F. If P is a query parameter of F 2760: ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2761: ** a pointer to an empty string. 2762: ** 2763: ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2764: ** parameter and returns true (1) or false (0) according to the value 1.3 ! misho 2765: ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the ! 2766: ** value of query parameter P is one of "yes", "true", or "on" in any ! 2767: ** case or if the value begins with a non-zero number. The ! 2768: ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of ! 2769: ** query parameter P is one of "no", "false", or "off" in any case or ! 2770: ** if the value begins with a numeric zero. If P is not a query ! 2771: ** parameter on F or if the value of P is does not match any of the ! 2772: ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 1.2 misho 2773: ** 2774: ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2775: ** 64-bit signed integer and returns that integer, or D if P does not 2776: ** exist. If the value of P is something other than an integer, then 2777: ** zero is returned. 2778: ** 2779: ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2780: ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2781: ** is not a database file pathname pointer that SQLite passed into the xOpen 2782: ** VFS method, then the behavior of this routine is undefined and probably 2783: ** undesirable. 2784: */ 2785: SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2786: SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2787: SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2788: 2789: 2790: /* 2791: ** CAPI3REF: Error Codes And Messages 2792: ** 2793: ** ^The sqlite3_errcode() interface returns the numeric [result code] or 2794: ** [extended result code] for the most recent failed sqlite3_* API call 2795: ** associated with a [database connection]. If a prior API call failed 2796: ** but the most recent API call succeeded, the return value from 2797: ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2798: ** interface is the same except that it always returns the 2799: ** [extended result code] even when extended result codes are 2800: ** disabled. 2801: ** 2802: ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2803: ** text that describes the error, as either UTF-8 or UTF-16 respectively. 2804: ** ^(Memory to hold the error message string is managed internally. 2805: ** The application does not need to worry about freeing the result. 2806: ** However, the error string might be overwritten or deallocated by 2807: ** subsequent calls to other SQLite interface functions.)^ 2808: ** 1.3 ! misho 2809: ** ^The sqlite3_errstr() interface returns the English-language text ! 2810: ** that describes the [result code], as UTF-8. ! 2811: ** ^(Memory to hold the error message string is managed internally ! 2812: ** and must not be freed by the application)^. ! 2813: ** 1.2 misho 2814: ** When the serialized [threading mode] is in use, it might be the 2815: ** case that a second error occurs on a separate thread in between 2816: ** the time of the first error and the call to these interfaces. 2817: ** When that happens, the second error will be reported since these 2818: ** interfaces always report the most recent result. To avoid 2819: ** this, each thread can obtain exclusive use of the [database connection] D 2820: ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2821: ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2822: ** all calls to the interfaces listed here are completed. 2823: ** 2824: ** If an interface fails with SQLITE_MISUSE, that means the interface 2825: ** was invoked incorrectly by the application. In that case, the 2826: ** error code and message may or may not be set. 2827: */ 2828: SQLITE_API int sqlite3_errcode(sqlite3 *db); 2829: SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2830: SQLITE_API const char *sqlite3_errmsg(sqlite3*); 2831: SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 1.3 ! misho 2832: SQLITE_API const char *sqlite3_errstr(int); 1.2 misho 2833: 2834: /* 2835: ** CAPI3REF: SQL Statement Object 2836: ** KEYWORDS: {prepared statement} {prepared statements} 2837: ** 2838: ** An instance of this object represents a single SQL statement. 2839: ** This object is variously known as a "prepared statement" or a 2840: ** "compiled SQL statement" or simply as a "statement". 2841: ** 2842: ** The life of a statement object goes something like this: 2843: ** 2844: ** <ol> 2845: ** <li> Create the object using [sqlite3_prepare_v2()] or a related 2846: ** function. 2847: ** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2848: ** interfaces. 2849: ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2850: ** <li> Reset the statement using [sqlite3_reset()] then go back 2851: ** to step 2. Do this zero or more times. 2852: ** <li> Destroy the object using [sqlite3_finalize()]. 2853: ** </ol> 2854: ** 2855: ** Refer to documentation on individual methods above for additional 2856: ** information. 2857: */ 2858: typedef struct sqlite3_stmt sqlite3_stmt; 2859: 2860: /* 2861: ** CAPI3REF: Run-time Limits 2862: ** 2863: ** ^(This interface allows the size of various constructs to be limited 2864: ** on a connection by connection basis. The first parameter is the 2865: ** [database connection] whose limit is to be set or queried. The 2866: ** second parameter is one of the [limit categories] that define a 2867: ** class of constructs to be size limited. The third parameter is the 2868: ** new limit for that construct.)^ 2869: ** 2870: ** ^If the new limit is a negative number, the limit is unchanged. 2871: ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2872: ** [limits | hard upper bound] 2873: ** set at compile-time by a C preprocessor macro called 2874: ** [limits | SQLITE_MAX_<i>NAME</i>]. 2875: ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2876: ** ^Attempts to increase a limit above its hard upper bound are 2877: ** silently truncated to the hard upper bound. 2878: ** 2879: ** ^Regardless of whether or not the limit was changed, the 2880: ** [sqlite3_limit()] interface returns the prior value of the limit. 2881: ** ^Hence, to find the current value of a limit without changing it, 2882: ** simply invoke this interface with the third parameter set to -1. 2883: ** 2884: ** Run-time limits are intended for use in applications that manage 2885: ** both their own internal database and also databases that are controlled 2886: ** by untrusted external sources. An example application might be a 2887: ** web browser that has its own databases for storing history and 2888: ** separate databases controlled by JavaScript applications downloaded 2889: ** off the Internet. The internal databases can be given the 2890: ** large, default limits. Databases managed by external sources can 2891: ** be given much smaller limits designed to prevent a denial of service 2892: ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 2893: ** interface to further control untrusted SQL. The size of the database 2894: ** created by an untrusted script can be contained using the 2895: ** [max_page_count] [PRAGMA]. 2896: ** 2897: ** New run-time limit categories may be added in future releases. 2898: */ 2899: SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 2900: 2901: /* 2902: ** CAPI3REF: Run-Time Limit Categories 2903: ** KEYWORDS: {limit category} {*limit categories} 2904: ** 2905: ** These constants define various performance limits 2906: ** that can be lowered at run-time using [sqlite3_limit()]. 2907: ** The synopsis of the meanings of the various limits is shown below. 2908: ** Additional information is available at [limits | Limits in SQLite]. 2909: ** 2910: ** <dl> 2911: ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 2912: ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 2913: ** 2914: ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2915: ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 2916: ** 2917: ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 2918: ** <dd>The maximum number of columns in a table definition or in the 2919: ** result set of a [SELECT] or the maximum number of columns in an index 2920: ** or in an ORDER BY or GROUP BY clause.</dd>)^ 2921: ** 2922: ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2923: ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 2924: ** 2925: ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2926: ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 2927: ** 2928: ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 2929: ** <dd>The maximum number of instructions in a virtual machine program 2930: ** used to implement an SQL statement. This limit is not currently 2931: ** enforced, though that might be added in some future release of 2932: ** SQLite.</dd>)^ 2933: ** 2934: ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2935: ** <dd>The maximum number of arguments on a function.</dd>)^ 2936: ** 2937: ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 2938: ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 2939: ** 2940: ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 2941: ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2942: ** <dd>The maximum length of the pattern argument to the [LIKE] or 2943: ** [GLOB] operators.</dd>)^ 2944: ** 2945: ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 2946: ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2947: ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 2948: ** 2949: ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 2950: ** <dd>The maximum depth of recursion for triggers.</dd>)^ 2951: ** </dl> 2952: */ 2953: #define SQLITE_LIMIT_LENGTH 0 2954: #define SQLITE_LIMIT_SQL_LENGTH 1 2955: #define SQLITE_LIMIT_COLUMN 2 2956: #define SQLITE_LIMIT_EXPR_DEPTH 3 2957: #define SQLITE_LIMIT_COMPOUND_SELECT 4 2958: #define SQLITE_LIMIT_VDBE_OP 5 2959: #define SQLITE_LIMIT_FUNCTION_ARG 6 2960: #define SQLITE_LIMIT_ATTACHED 7 2961: #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2962: #define SQLITE_LIMIT_VARIABLE_NUMBER 9 2963: #define SQLITE_LIMIT_TRIGGER_DEPTH 10 2964: 2965: /* 2966: ** CAPI3REF: Compiling An SQL Statement 2967: ** KEYWORDS: {SQL statement compiler} 2968: ** 2969: ** To execute an SQL query, it must first be compiled into a byte-code 2970: ** program using one of these routines. 2971: ** 2972: ** The first argument, "db", is a [database connection] obtained from a 2973: ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 2974: ** [sqlite3_open16()]. The database connection must not have been closed. 2975: ** 2976: ** The second argument, "zSql", is the statement to be compiled, encoded 2977: ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2978: ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 2979: ** use UTF-16. 2980: ** 2981: ** ^If the nByte argument is less than zero, then zSql is read up to the 2982: ** first zero terminator. ^If nByte is non-negative, then it is the maximum 2983: ** number of bytes read from zSql. ^When nByte is non-negative, the 2984: ** zSql string ends at either the first '\000' or '\u0000' character or 2985: ** the nByte-th byte, whichever comes first. If the caller knows 2986: ** that the supplied string is nul-terminated, then there is a small 2987: ** performance advantage to be gained by passing an nByte parameter that 2988: ** is equal to the number of bytes in the input string <i>including</i> 2989: ** the nul-terminator bytes as this saves SQLite from having to 2990: ** make a copy of the input string. 2991: ** 2992: ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 2993: ** past the end of the first SQL statement in zSql. These routines only 2994: ** compile the first statement in zSql, so *pzTail is left pointing to 2995: ** what remains uncompiled. 2996: ** 2997: ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 2998: ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 2999: ** to NULL. ^If the input text contains no SQL (if the input is an empty 3000: ** string or a comment) then *ppStmt is set to NULL. 3001: ** The calling procedure is responsible for deleting the compiled 3002: ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3003: ** ppStmt may not be NULL. 3004: ** 3005: ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3006: ** otherwise an [error code] is returned. 3007: ** 3008: ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3009: ** recommended for all new programs. The two older interfaces are retained 3010: ** for backwards compatibility, but their use is discouraged. 3011: ** ^In the "v2" interfaces, the prepared statement 3012: ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3013: ** original SQL text. This causes the [sqlite3_step()] interface to 3014: ** behave differently in three ways: 3015: ** 3016: ** <ol> 3017: ** <li> 3018: ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3019: ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3020: ** statement and try to run it again. 3021: ** </li> 3022: ** 3023: ** <li> 3024: ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3025: ** [error codes] or [extended error codes]. ^The legacy behavior was that 3026: ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3027: ** and the application would have to make a second call to [sqlite3_reset()] 3028: ** in order to find the underlying cause of the problem. With the "v2" prepare 3029: ** interfaces, the underlying reason for the error is returned immediately. 3030: ** </li> 3031: ** 3032: ** <li> 3033: ** ^If the specific value bound to [parameter | host parameter] in the 3034: ** WHERE clause might influence the choice of query plan for a statement, 3035: ** then the statement will be automatically recompiled, as if there had been 3036: ** a schema change, on the first [sqlite3_step()] call following any change 3037: ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3038: ** ^The specific value of WHERE-clause [parameter] might influence the 3039: ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3040: ** or [GLOB] operator or if the parameter is compared to an indexed column 3041: ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3042: ** the 3043: ** </li> 3044: ** </ol> 3045: */ 3046: SQLITE_API int sqlite3_prepare( 3047: sqlite3 *db, /* Database handle */ 3048: const char *zSql, /* SQL statement, UTF-8 encoded */ 3049: int nByte, /* Maximum length of zSql in bytes. */ 3050: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3051: const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3052: ); 3053: SQLITE_API int sqlite3_prepare_v2( 3054: sqlite3 *db, /* Database handle */ 3055: const char *zSql, /* SQL statement, UTF-8 encoded */ 3056: int nByte, /* Maximum length of zSql in bytes. */ 3057: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3058: const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3059: ); 3060: SQLITE_API int sqlite3_prepare16( 3061: sqlite3 *db, /* Database handle */ 3062: const void *zSql, /* SQL statement, UTF-16 encoded */ 3063: int nByte, /* Maximum length of zSql in bytes. */ 3064: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3065: const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3066: ); 3067: SQLITE_API int sqlite3_prepare16_v2( 3068: sqlite3 *db, /* Database handle */ 3069: const void *zSql, /* SQL statement, UTF-16 encoded */ 3070: int nByte, /* Maximum length of zSql in bytes. */ 3071: sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3072: const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3073: ); 3074: 3075: /* 3076: ** CAPI3REF: Retrieving Statement SQL 3077: ** 3078: ** ^This interface can be used to retrieve a saved copy of the original 3079: ** SQL text used to create a [prepared statement] if that statement was 3080: ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3081: */ 3082: SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3083: 3084: /* 3085: ** CAPI3REF: Determine If An SQL Statement Writes The Database 3086: ** 3087: ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3088: ** and only if the [prepared statement] X makes no direct changes to 3089: ** the content of the database file. 3090: ** 3091: ** Note that [application-defined SQL functions] or 3092: ** [virtual tables] might change the database indirectly as a side effect. 3093: ** ^(For example, if an application defines a function "eval()" that 3094: ** calls [sqlite3_exec()], then the following SQL statement would 3095: ** change the database file through side-effects: 3096: ** 3097: ** <blockquote><pre> 3098: ** SELECT eval('DELETE FROM t1') FROM t2; 3099: ** </pre></blockquote> 3100: ** 3101: ** But because the [SELECT] statement does not change the database file 3102: ** directly, sqlite3_stmt_readonly() would still return true.)^ 3103: ** 3104: ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3105: ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3106: ** since the statements themselves do not actually modify the database but 3107: ** rather they control the timing of when other statements modify the 3108: ** database. ^The [ATTACH] and [DETACH] statements also cause 3109: ** sqlite3_stmt_readonly() to return true since, while those statements 3110: ** change the configuration of a database connection, they do not make 3111: ** changes to the content of the database files on disk. 3112: */ 3113: SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3114: 3115: /* 3116: ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3117: ** 3118: ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3119: ** [prepared statement] S has been stepped at least once using 3120: ** [sqlite3_step(S)] but has not run to completion and/or has not 3121: ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3122: ** interface returns false if S is a NULL pointer. If S is not a 3123: ** NULL pointer and is not a pointer to a valid [prepared statement] 3124: ** object, then the behavior is undefined and probably undesirable. 3125: ** 3126: ** This interface can be used in combination [sqlite3_next_stmt()] 3127: ** to locate all prepared statements associated with a database 3128: ** connection that are in need of being reset. This can be used, 3129: ** for example, in diagnostic routines to search for prepared 3130: ** statements that are holding a transaction open. 3131: */ 3132: SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3133: 3134: /* 3135: ** CAPI3REF: Dynamically Typed Value Object 3136: ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3137: ** 3138: ** SQLite uses the sqlite3_value object to represent all values 3139: ** that can be stored in a database table. SQLite uses dynamic typing 3140: ** for the values it stores. ^Values stored in sqlite3_value objects 3141: ** can be integers, floating point values, strings, BLOBs, or NULL. 3142: ** 3143: ** An sqlite3_value object may be either "protected" or "unprotected". 3144: ** Some interfaces require a protected sqlite3_value. Other interfaces 3145: ** will accept either a protected or an unprotected sqlite3_value. 3146: ** Every interface that accepts sqlite3_value arguments specifies 3147: ** whether or not it requires a protected sqlite3_value. 3148: ** 3149: ** The terms "protected" and "unprotected" refer to whether or not 3150: ** a mutex is held. An internal mutex is held for a protected 3151: ** sqlite3_value object but no mutex is held for an unprotected 3152: ** sqlite3_value object. If SQLite is compiled to be single-threaded 3153: ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3154: ** or if SQLite is run in one of reduced mutex modes 3155: ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3156: ** then there is no distinction between protected and unprotected 3157: ** sqlite3_value objects and they can be used interchangeably. However, 3158: ** for maximum code portability it is recommended that applications 3159: ** still make the distinction between protected and unprotected 3160: ** sqlite3_value objects even when not strictly required. 3161: ** 3162: ** ^The sqlite3_value objects that are passed as parameters into the 3163: ** implementation of [application-defined SQL functions] are protected. 3164: ** ^The sqlite3_value object returned by 3165: ** [sqlite3_column_value()] is unprotected. 3166: ** Unprotected sqlite3_value objects may only be used with 3167: ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3168: ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3169: ** interfaces require protected sqlite3_value objects. 3170: */ 3171: typedef struct Mem sqlite3_value; 3172: 3173: /* 3174: ** CAPI3REF: SQL Function Context Object 3175: ** 3176: ** The context in which an SQL function executes is stored in an 3177: ** sqlite3_context object. ^A pointer to an sqlite3_context object 3178: ** is always first parameter to [application-defined SQL functions]. 3179: ** The application-defined SQL function implementation will pass this 3180: ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3181: ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3182: ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3183: ** and/or [sqlite3_set_auxdata()]. 3184: */ 3185: typedef struct sqlite3_context sqlite3_context; 3186: 3187: /* 3188: ** CAPI3REF: Binding Values To Prepared Statements 3189: ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3190: ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3191: ** 3192: ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3193: ** literals may be replaced by a [parameter] that matches one of following 3194: ** templates: 3195: ** 3196: ** <ul> 3197: ** <li> ? 3198: ** <li> ?NNN 3199: ** <li> :VVV 3200: ** <li> @VVV 3201: ** <li> $VVV 3202: ** </ul> 3203: ** 3204: ** In the templates above, NNN represents an integer literal, 3205: ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3206: ** parameters (also called "host parameter names" or "SQL parameters") 3207: ** can be set using the sqlite3_bind_*() routines defined here. 3208: ** 3209: ** ^The first argument to the sqlite3_bind_*() routines is always 3210: ** a pointer to the [sqlite3_stmt] object returned from 3211: ** [sqlite3_prepare_v2()] or its variants. 3212: ** 3213: ** ^The second argument is the index of the SQL parameter to be set. 3214: ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3215: ** SQL parameter is used more than once, second and subsequent 3216: ** occurrences have the same index as the first occurrence. 3217: ** ^The index for named parameters can be looked up using the 3218: ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3219: ** for "?NNN" parameters is the value of NNN. 3220: ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3221: ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3222: ** 3223: ** ^The third argument is the value to bind to the parameter. 3224: ** 3225: ** ^(In those routines that have a fourth argument, its value is the 3226: ** number of bytes in the parameter. To be clear: the value is the 3227: ** number of <u>bytes</u> in the value, not the number of characters.)^ 1.3 ! misho 3228: ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() ! 3229: ** is negative, then the length of the string is 1.2 misho 3230: ** the number of bytes up to the first zero terminator. 1.3 ! misho 3231: ** If the fourth parameter to sqlite3_bind_blob() is negative, then ! 3232: ** the behavior is undefined. 1.2 misho 3233: ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3234: ** or sqlite3_bind_text16() then that parameter must be the byte offset 3235: ** where the NUL terminator would occur assuming the string were NUL 3236: ** terminated. If any NUL characters occur at byte offsets less than 3237: ** the value of the fourth parameter then the resulting string value will 3238: ** contain embedded NULs. The result of expressions involving strings 3239: ** with embedded NULs is undefined. 3240: ** 3241: ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3242: ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3243: ** string after SQLite has finished with it. ^The destructor is called 3244: ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3245: ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3246: ** ^If the fifth argument is 3247: ** the special value [SQLITE_STATIC], then SQLite assumes that the 3248: ** information is in static, unmanaged space and does not need to be freed. 3249: ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3250: ** SQLite makes its own private copy of the data immediately, before 3251: ** the sqlite3_bind_*() routine returns. 3252: ** 3253: ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3254: ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3255: ** (just an integer to hold its size) while it is being processed. 3256: ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3257: ** content is later written using 3258: ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3259: ** ^A negative value for the zeroblob results in a zero-length BLOB. 3260: ** 3261: ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3262: ** for the [prepared statement] or with a prepared statement for which 3263: ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3264: ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3265: ** routine is passed a [prepared statement] that has been finalized, the 3266: ** result is undefined and probably harmful. 3267: ** 3268: ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3269: ** ^Unbound parameters are interpreted as NULL. 3270: ** 3271: ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3272: ** [error code] if anything goes wrong. 3273: ** ^[SQLITE_RANGE] is returned if the parameter 3274: ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3275: ** 3276: ** See also: [sqlite3_bind_parameter_count()], 3277: ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3278: */ 3279: SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3280: SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3281: SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3282: SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3283: SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3284: SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3285: SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3286: SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3287: SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3288: 3289: /* 3290: ** CAPI3REF: Number Of SQL Parameters 3291: ** 3292: ** ^This routine can be used to find the number of [SQL parameters] 3293: ** in a [prepared statement]. SQL parameters are tokens of the 3294: ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3295: ** placeholders for values that are [sqlite3_bind_blob | bound] 3296: ** to the parameters at a later time. 3297: ** 3298: ** ^(This routine actually returns the index of the largest (rightmost) 3299: ** parameter. For all forms except ?NNN, this will correspond to the 3300: ** number of unique parameters. If parameters of the ?NNN form are used, 3301: ** there may be gaps in the list.)^ 3302: ** 3303: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3304: ** [sqlite3_bind_parameter_name()], and 3305: ** [sqlite3_bind_parameter_index()]. 3306: */ 3307: SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3308: 3309: /* 3310: ** CAPI3REF: Name Of A Host Parameter 3311: ** 3312: ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3313: ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3314: ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3315: ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3316: ** respectively. 3317: ** In other words, the initial ":" or "$" or "@" or "?" 3318: ** is included as part of the name.)^ 3319: ** ^Parameters of the form "?" without a following integer have no name 3320: ** and are referred to as "nameless" or "anonymous parameters". 3321: ** 3322: ** ^The first host parameter has an index of 1, not 0. 3323: ** 3324: ** ^If the value N is out of range or if the N-th parameter is 3325: ** nameless, then NULL is returned. ^The returned string is 3326: ** always in UTF-8 encoding even if the named parameter was 3327: ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3328: ** [sqlite3_prepare16_v2()]. 3329: ** 3330: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3331: ** [sqlite3_bind_parameter_count()], and 3332: ** [sqlite3_bind_parameter_index()]. 3333: */ 3334: SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3335: 3336: /* 3337: ** CAPI3REF: Index Of A Parameter With A Given Name 3338: ** 3339: ** ^Return the index of an SQL parameter given its name. ^The 3340: ** index value returned is suitable for use as the second 3341: ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3342: ** is returned if no matching parameter is found. ^The parameter 3343: ** name must be given in UTF-8 even if the original statement 3344: ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3345: ** 3346: ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3347: ** [sqlite3_bind_parameter_count()], and 3348: ** [sqlite3_bind_parameter_index()]. 3349: */ 3350: SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3351: 3352: /* 3353: ** CAPI3REF: Reset All Bindings On A Prepared Statement 3354: ** 3355: ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3356: ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3357: ** ^Use this routine to reset all host parameters to NULL. 3358: */ 3359: SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3360: 3361: /* 3362: ** CAPI3REF: Number Of Columns In A Result Set 3363: ** 3364: ** ^Return the number of columns in the result set returned by the 3365: ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3366: ** statement that does not return data (for example an [UPDATE]). 3367: ** 3368: ** See also: [sqlite3_data_count()] 3369: */ 3370: SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3371: 3372: /* 3373: ** CAPI3REF: Column Names In A Result Set 3374: ** 3375: ** ^These routines return the name assigned to a particular column 3376: ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3377: ** interface returns a pointer to a zero-terminated UTF-8 string 3378: ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3379: ** UTF-16 string. ^The first parameter is the [prepared statement] 3380: ** that implements the [SELECT] statement. ^The second parameter is the 3381: ** column number. ^The leftmost column is number 0. 3382: ** 3383: ** ^The returned string pointer is valid until either the [prepared statement] 3384: ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3385: ** reprepared by the first call to [sqlite3_step()] for a particular run 3386: ** or until the next call to 3387: ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3388: ** 3389: ** ^If sqlite3_malloc() fails during the processing of either routine 3390: ** (for example during a conversion from UTF-8 to UTF-16) then a 3391: ** NULL pointer is returned. 3392: ** 3393: ** ^The name of a result column is the value of the "AS" clause for 3394: ** that column, if there is an AS clause. If there is no AS clause 3395: ** then the name of the column is unspecified and may change from 3396: ** one release of SQLite to the next. 3397: */ 3398: SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3399: SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3400: 3401: /* 3402: ** CAPI3REF: Source Of Data In A Query Result 3403: ** 3404: ** ^These routines provide a means to determine the database, table, and 3405: ** table column that is the origin of a particular result column in 3406: ** [SELECT] statement. 3407: ** ^The name of the database or table or column can be returned as 3408: ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3409: ** the database name, the _table_ routines return the table name, and 3410: ** the origin_ routines return the column name. 3411: ** ^The returned string is valid until the [prepared statement] is destroyed 3412: ** using [sqlite3_finalize()] or until the statement is automatically 3413: ** reprepared by the first call to [sqlite3_step()] for a particular run 3414: ** or until the same information is requested 3415: ** again in a different encoding. 3416: ** 3417: ** ^The names returned are the original un-aliased names of the 3418: ** database, table, and column. 3419: ** 3420: ** ^The first argument to these interfaces is a [prepared statement]. 3421: ** ^These functions return information about the Nth result column returned by 3422: ** the statement, where N is the second function argument. 3423: ** ^The left-most column is column 0 for these routines. 3424: ** 3425: ** ^If the Nth column returned by the statement is an expression or 3426: ** subquery and is not a column value, then all of these functions return 3427: ** NULL. ^These routine might also return NULL if a memory allocation error 3428: ** occurs. ^Otherwise, they return the name of the attached database, table, 3429: ** or column that query result column was extracted from. 3430: ** 3431: ** ^As with all other SQLite APIs, those whose names end with "16" return 3432: ** UTF-16 encoded strings and the other functions return UTF-8. 3433: ** 3434: ** ^These APIs are only available if the library was compiled with the 3435: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3436: ** 3437: ** If two or more threads call one or more of these routines against the same 3438: ** prepared statement and column at the same time then the results are 3439: ** undefined. 3440: ** 3441: ** If two or more threads call one or more 3442: ** [sqlite3_column_database_name | column metadata interfaces] 3443: ** for the same [prepared statement] and result column 3444: ** at the same time then the results are undefined. 3445: */ 3446: SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3447: SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3448: SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3449: SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3450: SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3451: SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3452: 3453: /* 3454: ** CAPI3REF: Declared Datatype Of A Query Result 3455: ** 3456: ** ^(The first parameter is a [prepared statement]. 3457: ** If this statement is a [SELECT] statement and the Nth column of the 3458: ** returned result set of that [SELECT] is a table column (not an 3459: ** expression or subquery) then the declared type of the table 3460: ** column is returned.)^ ^If the Nth column of the result set is an 3461: ** expression or subquery, then a NULL pointer is returned. 3462: ** ^The returned string is always UTF-8 encoded. 3463: ** 3464: ** ^(For example, given the database schema: 3465: ** 3466: ** CREATE TABLE t1(c1 VARIANT); 3467: ** 3468: ** and the following statement to be compiled: 3469: ** 3470: ** SELECT c1 + 1, c1 FROM t1; 3471: ** 3472: ** this routine would return the string "VARIANT" for the second result 3473: ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3474: ** 3475: ** ^SQLite uses dynamic run-time typing. ^So just because a column 3476: ** is declared to contain a particular type does not mean that the 3477: ** data stored in that column is of the declared type. SQLite is 3478: ** strongly typed, but the typing is dynamic not static. ^Type 3479: ** is associated with individual values, not with the containers 3480: ** used to hold those values. 3481: */ 3482: SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3483: SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3484: 3485: /* 3486: ** CAPI3REF: Evaluate An SQL Statement 3487: ** 3488: ** After a [prepared statement] has been prepared using either 3489: ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3490: ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3491: ** must be called one or more times to evaluate the statement. 3492: ** 3493: ** The details of the behavior of the sqlite3_step() interface depend 3494: ** on whether the statement was prepared using the newer "v2" interface 3495: ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3496: ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3497: ** new "v2" interface is recommended for new applications but the legacy 3498: ** interface will continue to be supported. 3499: ** 3500: ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3501: ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3502: ** ^With the "v2" interface, any of the other [result codes] or 3503: ** [extended result codes] might be returned as well. 3504: ** 3505: ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3506: ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3507: ** or occurs outside of an explicit transaction, then you can retry the 3508: ** statement. If the statement is not a [COMMIT] and occurs within an 3509: ** explicit transaction then you should rollback the transaction before 3510: ** continuing. 3511: ** 3512: ** ^[SQLITE_DONE] means that the statement has finished executing 3513: ** successfully. sqlite3_step() should not be called again on this virtual 3514: ** machine without first calling [sqlite3_reset()] to reset the virtual 3515: ** machine back to its initial state. 3516: ** 3517: ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3518: ** is returned each time a new row of data is ready for processing by the 3519: ** caller. The values may be accessed using the [column access functions]. 3520: ** sqlite3_step() is called again to retrieve the next row of data. 3521: ** 3522: ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3523: ** violation) has occurred. sqlite3_step() should not be called again on 3524: ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3525: ** ^With the legacy interface, a more specific error code (for example, 3526: ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3527: ** can be obtained by calling [sqlite3_reset()] on the 3528: ** [prepared statement]. ^In the "v2" interface, 3529: ** the more specific error code is returned directly by sqlite3_step(). 3530: ** 3531: ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3532: ** Perhaps it was called on a [prepared statement] that has 3533: ** already been [sqlite3_finalize | finalized] or on one that had 3534: ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3535: ** be the case that the same database connection is being used by two or 3536: ** more threads at the same moment in time. 3537: ** 3538: ** For all versions of SQLite up to and including 3.6.23.1, a call to 3539: ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3540: ** other than [SQLITE_ROW] before any subsequent invocation of 3541: ** sqlite3_step(). Failure to reset the prepared statement using 3542: ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3543: ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3544: ** calling [sqlite3_reset()] automatically in this circumstance rather 3545: ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3546: ** break because any application that ever receives an SQLITE_MISUSE error 3547: ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3548: ** can be used to restore the legacy behavior. 3549: ** 3550: ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3551: ** API always returns a generic error code, [SQLITE_ERROR], following any 3552: ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3553: ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3554: ** specific [error codes] that better describes the error. 3555: ** We admit that this is a goofy design. The problem has been fixed 3556: ** with the "v2" interface. If you prepare all of your SQL statements 3557: ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3558: ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3559: ** then the more specific [error codes] are returned directly 3560: ** by sqlite3_step(). The use of the "v2" interface is recommended. 3561: */ 3562: SQLITE_API int sqlite3_step(sqlite3_stmt*); 3563: 3564: /* 3565: ** CAPI3REF: Number of columns in a result set 3566: ** 3567: ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3568: ** current row of the result set of [prepared statement] P. 3569: ** ^If prepared statement P does not have results ready to return 3570: ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3571: ** interfaces) then sqlite3_data_count(P) returns 0. 3572: ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3573: ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3574: ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3575: ** will return non-zero if previous call to [sqlite3_step](P) returned 3576: ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3577: ** where it always returns zero since each step of that multi-step 3578: ** pragma returns 0 columns of data. 3579: ** 3580: ** See also: [sqlite3_column_count()] 3581: */ 3582: SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3583: 3584: /* 3585: ** CAPI3REF: Fundamental Datatypes 3586: ** KEYWORDS: SQLITE_TEXT 3587: ** 3588: ** ^(Every value in SQLite has one of five fundamental datatypes: 3589: ** 3590: ** <ul> 3591: ** <li> 64-bit signed integer 3592: ** <li> 64-bit IEEE floating point number 3593: ** <li> string 3594: ** <li> BLOB 3595: ** <li> NULL 3596: ** </ul>)^ 3597: ** 3598: ** These constants are codes for each of those types. 3599: ** 3600: ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3601: ** for a completely different meaning. Software that links against both 3602: ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3603: ** SQLITE_TEXT. 3604: */ 3605: #define SQLITE_INTEGER 1 3606: #define SQLITE_FLOAT 2 3607: #define SQLITE_BLOB 4 3608: #define SQLITE_NULL 5 3609: #ifdef SQLITE_TEXT 3610: # undef SQLITE_TEXT 3611: #else 3612: # define SQLITE_TEXT 3 3613: #endif 3614: #define SQLITE3_TEXT 3 3615: 3616: /* 3617: ** CAPI3REF: Result Values From A Query 3618: ** KEYWORDS: {column access functions} 3619: ** 3620: ** These routines form the "result set" interface. 3621: ** 3622: ** ^These routines return information about a single column of the current 3623: ** result row of a query. ^In every case the first argument is a pointer 3624: ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3625: ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3626: ** and the second argument is the index of the column for which information 3627: ** should be returned. ^The leftmost column of the result set has the index 0. 3628: ** ^The number of columns in the result can be determined using 3629: ** [sqlite3_column_count()]. 3630: ** 3631: ** If the SQL statement does not currently point to a valid row, or if the 3632: ** column index is out of range, the result is undefined. 3633: ** These routines may only be called when the most recent call to 3634: ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3635: ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3636: ** If any of these routines are called after [sqlite3_reset()] or 3637: ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3638: ** something other than [SQLITE_ROW], the results are undefined. 3639: ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3640: ** are called from a different thread while any of these routines 3641: ** are pending, then the results are undefined. 3642: ** 3643: ** ^The sqlite3_column_type() routine returns the 3644: ** [SQLITE_INTEGER | datatype code] for the initial data type 3645: ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3646: ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3647: ** returned by sqlite3_column_type() is only meaningful if no type 3648: ** conversions have occurred as described below. After a type conversion, 3649: ** the value returned by sqlite3_column_type() is undefined. Future 3650: ** versions of SQLite may change the behavior of sqlite3_column_type() 3651: ** following a type conversion. 3652: ** 3653: ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3654: ** routine returns the number of bytes in that BLOB or string. 3655: ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3656: ** the string to UTF-8 and then returns the number of bytes. 3657: ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3658: ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3659: ** the number of bytes in that string. 3660: ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3661: ** 3662: ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3663: ** routine returns the number of bytes in that BLOB or string. 3664: ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3665: ** the string to UTF-16 and then returns the number of bytes. 3666: ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3667: ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3668: ** the number of bytes in that string. 3669: ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3670: ** 3671: ** ^The values returned by [sqlite3_column_bytes()] and 3672: ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3673: ** of the string. ^For clarity: the values returned by 3674: ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3675: ** bytes in the string, not the number of characters. 3676: ** 3677: ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3678: ** even empty strings, are always zero-terminated. ^The return 3679: ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3680: ** 3681: ** ^The object returned by [sqlite3_column_value()] is an 3682: ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3683: ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3684: ** If the [unprotected sqlite3_value] object returned by 3685: ** [sqlite3_column_value()] is used in any other way, including calls 3686: ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3687: ** or [sqlite3_value_bytes()], then the behavior is undefined. 3688: ** 3689: ** These routines attempt to convert the value where appropriate. ^For 3690: ** example, if the internal representation is FLOAT and a text result 3691: ** is requested, [sqlite3_snprintf()] is used internally to perform the 3692: ** conversion automatically. ^(The following table details the conversions 3693: ** that are applied: 3694: ** 3695: ** <blockquote> 3696: ** <table border="1"> 3697: ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3698: ** 3699: ** <tr><td> NULL <td> INTEGER <td> Result is 0 3700: ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3701: ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3702: ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3703: ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3704: ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3705: ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3706: ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3707: ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3708: ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3709: ** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3710: ** <tr><td> TEXT <td> FLOAT <td> Use atof() 3711: ** <tr><td> TEXT <td> BLOB <td> No change 3712: ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3713: ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3714: ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3715: ** </table> 3716: ** </blockquote>)^ 3717: ** 3718: ** The table above makes reference to standard C library functions atoi() 3719: ** and atof(). SQLite does not really use these functions. It has its 3720: ** own equivalent internal routines. The atoi() and atof() names are 3721: ** used in the table for brevity and because they are familiar to most 3722: ** C programmers. 3723: ** 3724: ** Note that when type conversions occur, pointers returned by prior 3725: ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3726: ** sqlite3_column_text16() may be invalidated. 3727: ** Type conversions and pointer invalidations might occur 3728: ** in the following cases: 3729: ** 3730: ** <ul> 3731: ** <li> The initial content is a BLOB and sqlite3_column_text() or 3732: ** sqlite3_column_text16() is called. A zero-terminator might 3733: ** need to be added to the string.</li> 3734: ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3735: ** sqlite3_column_text16() is called. The content must be converted 3736: ** to UTF-16.</li> 3737: ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3738: ** sqlite3_column_text() is called. The content must be converted 3739: ** to UTF-8.</li> 3740: ** </ul> 3741: ** 3742: ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3743: ** not invalidate a prior pointer, though of course the content of the buffer 3744: ** that the prior pointer references will have been modified. Other kinds 3745: ** of conversion are done in place when it is possible, but sometimes they 3746: ** are not possible and in those cases prior pointers are invalidated. 3747: ** 3748: ** The safest and easiest to remember policy is to invoke these routines 3749: ** in one of the following ways: 3750: ** 3751: ** <ul> 3752: ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3753: ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3754: ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3755: ** </ul> 3756: ** 3757: ** In other words, you should call sqlite3_column_text(), 3758: ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3759: ** into the desired format, then invoke sqlite3_column_bytes() or 3760: ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3761: ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3762: ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3763: ** with calls to sqlite3_column_bytes(). 3764: ** 3765: ** ^The pointers returned are valid until a type conversion occurs as 3766: ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3767: ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3768: ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3769: ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3770: ** [sqlite3_free()]. 3771: ** 3772: ** ^(If a memory allocation error occurs during the evaluation of any 3773: ** of these routines, a default value is returned. The default value 3774: ** is either the integer 0, the floating point number 0.0, or a NULL 3775: ** pointer. Subsequent calls to [sqlite3_errcode()] will return 3776: ** [SQLITE_NOMEM].)^ 3777: */ 3778: SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3779: SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3780: SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3781: SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3782: SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3783: SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3784: SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3785: SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3786: SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3787: SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3788: 3789: /* 3790: ** CAPI3REF: Destroy A Prepared Statement Object 3791: ** 3792: ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3793: ** ^If the most recent evaluation of the statement encountered no errors 3794: ** or if the statement is never been evaluated, then sqlite3_finalize() returns 3795: ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3796: ** sqlite3_finalize(S) returns the appropriate [error code] or 3797: ** [extended error code]. 3798: ** 3799: ** ^The sqlite3_finalize(S) routine can be called at any point during 3800: ** the life cycle of [prepared statement] S: 3801: ** before statement S is ever evaluated, after 3802: ** one or more calls to [sqlite3_reset()], or after any call 3803: ** to [sqlite3_step()] regardless of whether or not the statement has 3804: ** completed execution. 3805: ** 3806: ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3807: ** 3808: ** The application must finalize every [prepared statement] in order to avoid 3809: ** resource leaks. It is a grievous error for the application to try to use 3810: ** a prepared statement after it has been finalized. Any use of a prepared 3811: ** statement after it has been finalized can result in undefined and 3812: ** undesirable behavior such as segfaults and heap corruption. 3813: */ 3814: SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3815: 3816: /* 3817: ** CAPI3REF: Reset A Prepared Statement Object 3818: ** 3819: ** The sqlite3_reset() function is called to reset a [prepared statement] 3820: ** object back to its initial state, ready to be re-executed. 3821: ** ^Any SQL statement variables that had values bound to them using 3822: ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3823: ** Use [sqlite3_clear_bindings()] to reset the bindings. 3824: ** 3825: ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3826: ** back to the beginning of its program. 3827: ** 3828: ** ^If the most recent call to [sqlite3_step(S)] for the 3829: ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3830: ** or if [sqlite3_step(S)] has never before been called on S, 3831: ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3832: ** 3833: ** ^If the most recent call to [sqlite3_step(S)] for the 3834: ** [prepared statement] S indicated an error, then 3835: ** [sqlite3_reset(S)] returns an appropriate [error code]. 3836: ** 3837: ** ^The [sqlite3_reset(S)] interface does not change the values 3838: ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3839: */ 3840: SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3841: 3842: /* 3843: ** CAPI3REF: Create Or Redefine SQL Functions 3844: ** KEYWORDS: {function creation routines} 3845: ** KEYWORDS: {application-defined SQL function} 3846: ** KEYWORDS: {application-defined SQL functions} 3847: ** 3848: ** ^These functions (collectively known as "function creation routines") 3849: ** are used to add SQL functions or aggregates or to redefine the behavior 3850: ** of existing SQL functions or aggregates. The only differences between 3851: ** these routines are the text encoding expected for 3852: ** the second parameter (the name of the function being created) 3853: ** and the presence or absence of a destructor callback for 3854: ** the application data pointer. 3855: ** 3856: ** ^The first parameter is the [database connection] to which the SQL 3857: ** function is to be added. ^If an application uses more than one database 3858: ** connection then application-defined SQL functions must be added 3859: ** to each database connection separately. 3860: ** 3861: ** ^The second parameter is the name of the SQL function to be created or 3862: ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3863: ** representation, exclusive of the zero-terminator. ^Note that the name 3864: ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3865: ** ^Any attempt to create a function with a longer name 3866: ** will result in [SQLITE_MISUSE] being returned. 3867: ** 3868: ** ^The third parameter (nArg) 3869: ** is the number of arguments that the SQL function or 3870: ** aggregate takes. ^If this parameter is -1, then the SQL function or 3871: ** aggregate may take any number of arguments between 0 and the limit 3872: ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3873: ** parameter is less than -1 or greater than 127 then the behavior is 3874: ** undefined. 3875: ** 3876: ** ^The fourth parameter, eTextRep, specifies what 3877: ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3878: ** its parameters. Every SQL function implementation must be able to work 3879: ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3880: ** more efficient with one encoding than another. ^An application may 3881: ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3882: ** times with the same function but with different values of eTextRep. 3883: ** ^When multiple implementations of the same function are available, SQLite 3884: ** will pick the one that involves the least amount of data conversion. 3885: ** If there is only a single implementation which does not care what text 3886: ** encoding is used, then the fourth argument should be [SQLITE_ANY]. 3887: ** 3888: ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 3889: ** function can gain access to this pointer using [sqlite3_user_data()].)^ 3890: ** 3891: ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 3892: ** pointers to C-language functions that implement the SQL function or 3893: ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 3894: ** callback only; NULL pointers must be passed as the xStep and xFinal 3895: ** parameters. ^An aggregate SQL function requires an implementation of xStep 3896: ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 3897: ** SQL function or aggregate, pass NULL pointers for all three function 3898: ** callbacks. 3899: ** 3900: ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 3901: ** then it is destructor for the application data pointer. 3902: ** The destructor is invoked when the function is deleted, either by being 3903: ** overloaded or when the database connection closes.)^ 3904: ** ^The destructor is also invoked if the call to 3905: ** sqlite3_create_function_v2() fails. 3906: ** ^When the destructor callback of the tenth parameter is invoked, it 3907: ** is passed a single argument which is a copy of the application data 3908: ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 3909: ** 3910: ** ^It is permitted to register multiple implementations of the same 3911: ** functions with the same name but with either differing numbers of 3912: ** arguments or differing preferred text encodings. ^SQLite will use 3913: ** the implementation that most closely matches the way in which the 3914: ** SQL function is used. ^A function implementation with a non-negative 3915: ** nArg parameter is a better match than a function implementation with 3916: ** a negative nArg. ^A function where the preferred text encoding 3917: ** matches the database encoding is a better 3918: ** match than a function where the encoding is different. 3919: ** ^A function where the encoding difference is between UTF16le and UTF16be 3920: ** is a closer match than a function where the encoding difference is 3921: ** between UTF8 and UTF16. 3922: ** 3923: ** ^Built-in functions may be overloaded by new application-defined functions. 3924: ** 3925: ** ^An application-defined function is permitted to call other 3926: ** SQLite interfaces. However, such calls must not 3927: ** close the database connection nor finalize or reset the prepared 3928: ** statement in which the function is running. 3929: */ 3930: SQLITE_API int sqlite3_create_function( 3931: sqlite3 *db, 3932: const char *zFunctionName, 3933: int nArg, 3934: int eTextRep, 3935: void *pApp, 3936: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3937: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3938: void (*xFinal)(sqlite3_context*) 3939: ); 3940: SQLITE_API int sqlite3_create_function16( 3941: sqlite3 *db, 3942: const void *zFunctionName, 3943: int nArg, 3944: int eTextRep, 3945: void *pApp, 3946: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3947: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3948: void (*xFinal)(sqlite3_context*) 3949: ); 3950: SQLITE_API int sqlite3_create_function_v2( 3951: sqlite3 *db, 3952: const char *zFunctionName, 3953: int nArg, 3954: int eTextRep, 3955: void *pApp, 3956: void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3957: void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3958: void (*xFinal)(sqlite3_context*), 3959: void(*xDestroy)(void*) 3960: ); 3961: 3962: /* 3963: ** CAPI3REF: Text Encodings 3964: ** 3965: ** These constant define integer codes that represent the various 3966: ** text encodings supported by SQLite. 3967: */ 3968: #define SQLITE_UTF8 1 3969: #define SQLITE_UTF16LE 2 3970: #define SQLITE_UTF16BE 3 3971: #define SQLITE_UTF16 4 /* Use native byte order */ 3972: #define SQLITE_ANY 5 /* sqlite3_create_function only */ 3973: #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3974: 3975: /* 3976: ** CAPI3REF: Deprecated Functions 3977: ** DEPRECATED 3978: ** 3979: ** These functions are [deprecated]. In order to maintain 3980: ** backwards compatibility with older code, these functions continue 3981: ** to be supported. However, new applications should avoid 3982: ** the use of these functions. To help encourage people to avoid 3983: ** using these functions, we are not going to tell you what they do. 3984: */ 3985: #ifndef SQLITE_OMIT_DEPRECATED 3986: SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 3987: SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 3988: SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3989: SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 3990: SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 3991: SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3992: #endif 3993: 3994: /* 3995: ** CAPI3REF: Obtaining SQL Function Parameter Values 3996: ** 3997: ** The C-language implementation of SQL functions and aggregates uses 3998: ** this set of interface routines to access the parameter values on 3999: ** the function or aggregate. 4000: ** 4001: ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4002: ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4003: ** define callbacks that implement the SQL functions and aggregates. 4004: ** The 3rd parameter to these callbacks is an array of pointers to 4005: ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4006: ** each parameter to the SQL function. These routines are used to 4007: ** extract values from the [sqlite3_value] objects. 4008: ** 4009: ** These routines work only with [protected sqlite3_value] objects. 4010: ** Any attempt to use these routines on an [unprotected sqlite3_value] 4011: ** object results in undefined behavior. 4012: ** 4013: ** ^These routines work just like the corresponding [column access functions] 4014: ** except that these routines take a single [protected sqlite3_value] object 4015: ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4016: ** 4017: ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4018: ** in the native byte-order of the host machine. ^The 4019: ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4020: ** extract UTF-16 strings as big-endian and little-endian respectively. 4021: ** 4022: ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4023: ** numeric affinity to the value. This means that an attempt is 4024: ** made to convert the value to an integer or floating point. If 4025: ** such a conversion is possible without loss of information (in other 4026: ** words, if the value is a string that looks like a number) 4027: ** then the conversion is performed. Otherwise no conversion occurs. 4028: ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4029: ** 4030: ** Please pay particular attention to the fact that the pointer returned 4031: ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4032: ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4033: ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4034: ** or [sqlite3_value_text16()]. 4035: ** 4036: ** These routines must be called from the same thread as 4037: ** the SQL function that supplied the [sqlite3_value*] parameters. 4038: */ 4039: SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4040: SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4041: SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4042: SQLITE_API double sqlite3_value_double(sqlite3_value*); 4043: SQLITE_API int sqlite3_value_int(sqlite3_value*); 4044: SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4045: SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4046: SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4047: SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4048: SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4049: SQLITE_API int sqlite3_value_type(sqlite3_value*); 4050: SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4051: 4052: /* 4053: ** CAPI3REF: Obtain Aggregate Function Context 4054: ** 4055: ** Implementations of aggregate SQL functions use this 4056: ** routine to allocate memory for storing their state. 4057: ** 4058: ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4059: ** for a particular aggregate function, SQLite 4060: ** allocates N of memory, zeroes out that memory, and returns a pointer 4061: ** to the new memory. ^On second and subsequent calls to 4062: ** sqlite3_aggregate_context() for the same aggregate function instance, 4063: ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4064: ** called once for each invocation of the xStep callback and then one 4065: ** last time when the xFinal callback is invoked. ^(When no rows match 4066: ** an aggregate query, the xStep() callback of the aggregate function 4067: ** implementation is never called and xFinal() is called exactly once. 4068: ** In those cases, sqlite3_aggregate_context() might be called for the 4069: ** first time from within xFinal().)^ 4070: ** 4071: ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is 4072: ** less than or equal to zero or if a memory allocate error occurs. 4073: ** 4074: ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4075: ** determined by the N parameter on first successful call. Changing the 4076: ** value of N in subsequent call to sqlite3_aggregate_context() within 4077: ** the same aggregate function instance will not resize the memory 4078: ** allocation.)^ 4079: ** 4080: ** ^SQLite automatically frees the memory allocated by 4081: ** sqlite3_aggregate_context() when the aggregate query concludes. 4082: ** 4083: ** The first parameter must be a copy of the 4084: ** [sqlite3_context | SQL function context] that is the first parameter 4085: ** to the xStep or xFinal callback routine that implements the aggregate 4086: ** function. 4087: ** 4088: ** This routine must be called from the same thread in which 4089: ** the aggregate SQL function is running. 4090: */ 4091: SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4092: 4093: /* 4094: ** CAPI3REF: User Data For Functions 4095: ** 4096: ** ^The sqlite3_user_data() interface returns a copy of 4097: ** the pointer that was the pUserData parameter (the 5th parameter) 4098: ** of the [sqlite3_create_function()] 4099: ** and [sqlite3_create_function16()] routines that originally 4100: ** registered the application defined function. 4101: ** 4102: ** This routine must be called from the same thread in which 4103: ** the application-defined function is running. 4104: */ 4105: SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4106: 4107: /* 4108: ** CAPI3REF: Database Connection For Functions 4109: ** 4110: ** ^The sqlite3_context_db_handle() interface returns a copy of 4111: ** the pointer to the [database connection] (the 1st parameter) 4112: ** of the [sqlite3_create_function()] 4113: ** and [sqlite3_create_function16()] routines that originally 4114: ** registered the application defined function. 4115: */ 4116: SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4117: 4118: /* 4119: ** CAPI3REF: Function Auxiliary Data 4120: ** 4121: ** The following two functions may be used by scalar SQL functions to 4122: ** associate metadata with argument values. If the same value is passed to 4123: ** multiple invocations of the same SQL function during query execution, under 4124: ** some circumstances the associated metadata may be preserved. This may 4125: ** be used, for example, to add a regular-expression matching scalar 4126: ** function. The compiled version of the regular expression is stored as 4127: ** metadata associated with the SQL value passed as the regular expression 4128: ** pattern. The compiled regular expression can be reused on multiple 4129: ** invocations of the same function so that the original pattern string 4130: ** does not need to be recompiled on each invocation. 4131: ** 4132: ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4133: ** associated by the sqlite3_set_auxdata() function with the Nth argument 4134: ** value to the application-defined function. ^If no metadata has been ever 4135: ** been set for the Nth argument of the function, or if the corresponding 4136: ** function parameter has changed since the meta-data was set, 4137: ** then sqlite3_get_auxdata() returns a NULL pointer. 4138: ** 4139: ** ^The sqlite3_set_auxdata() interface saves the metadata 4140: ** pointed to by its 3rd parameter as the metadata for the N-th 4141: ** argument of the application-defined function. Subsequent 4142: ** calls to sqlite3_get_auxdata() might return this data, if it has 4143: ** not been destroyed. 4144: ** ^If it is not NULL, SQLite will invoke the destructor 4145: ** function given by the 4th parameter to sqlite3_set_auxdata() on 4146: ** the metadata when the corresponding function parameter changes 4147: ** or when the SQL statement completes, whichever comes first. 4148: ** 4149: ** SQLite is free to call the destructor and drop metadata on any 4150: ** parameter of any function at any time. ^The only guarantee is that 4151: ** the destructor will be called before the metadata is dropped. 4152: ** 4153: ** ^(In practice, metadata is preserved between function calls for 4154: ** expressions that are constant at compile time. This includes literal 4155: ** values and [parameters].)^ 4156: ** 4157: ** These routines must be called from the same thread in which 4158: ** the SQL function is running. 4159: */ 4160: SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4161: SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4162: 4163: 4164: /* 4165: ** CAPI3REF: Constants Defining Special Destructor Behavior 4166: ** 4167: ** These are special values for the destructor that is passed in as the 4168: ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4169: ** argument is SQLITE_STATIC, it means that the content pointer is constant 4170: ** and will never change. It does not need to be destroyed. ^The 4171: ** SQLITE_TRANSIENT value means that the content will likely change in 4172: ** the near future and that SQLite should make its own private copy of 4173: ** the content before returning. 4174: ** 4175: ** The typedef is necessary to work around problems in certain 4176: ** C++ compilers. See ticket #2191. 4177: */ 4178: typedef void (*sqlite3_destructor_type)(void*); 4179: #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4180: #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4181: 4182: /* 4183: ** CAPI3REF: Setting The Result Of An SQL Function 4184: ** 4185: ** These routines are used by the xFunc or xFinal callbacks that 4186: ** implement SQL functions and aggregates. See 4187: ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4188: ** for additional information. 4189: ** 4190: ** These functions work very much like the [parameter binding] family of 4191: ** functions used to bind values to host parameters in prepared statements. 4192: ** Refer to the [SQL parameter] documentation for additional information. 4193: ** 4194: ** ^The sqlite3_result_blob() interface sets the result from 4195: ** an application-defined function to be the BLOB whose content is pointed 4196: ** to by the second parameter and which is N bytes long where N is the 4197: ** third parameter. 4198: ** 4199: ** ^The sqlite3_result_zeroblob() interfaces set the result of 4200: ** the application-defined function to be a BLOB containing all zero 4201: ** bytes and N bytes in size, where N is the value of the 2nd parameter. 4202: ** 4203: ** ^The sqlite3_result_double() interface sets the result from 4204: ** an application-defined function to be a floating point value specified 4205: ** by its 2nd argument. 4206: ** 4207: ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4208: ** cause the implemented SQL function to throw an exception. 4209: ** ^SQLite uses the string pointed to by the 4210: ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4211: ** as the text of an error message. ^SQLite interprets the error 4212: ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4213: ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4214: ** byte order. ^If the third parameter to sqlite3_result_error() 4215: ** or sqlite3_result_error16() is negative then SQLite takes as the error 4216: ** message all text up through the first zero character. 4217: ** ^If the third parameter to sqlite3_result_error() or 4218: ** sqlite3_result_error16() is non-negative then SQLite takes that many 4219: ** bytes (not characters) from the 2nd parameter as the error message. 4220: ** ^The sqlite3_result_error() and sqlite3_result_error16() 4221: ** routines make a private copy of the error message text before 4222: ** they return. Hence, the calling function can deallocate or 4223: ** modify the text after they return without harm. 4224: ** ^The sqlite3_result_error_code() function changes the error code 4225: ** returned by SQLite as a result of an error in a function. ^By default, 4226: ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4227: ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4228: ** 1.3 ! misho 4229: ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an ! 4230: ** error indicating that a string or BLOB is too long to represent. 1.2 misho 4231: ** 1.3 ! misho 4232: ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an ! 4233: ** error indicating that a memory allocation failed. 1.2 misho 4234: ** 4235: ** ^The sqlite3_result_int() interface sets the return value 4236: ** of the application-defined function to be the 32-bit signed integer 4237: ** value given in the 2nd argument. 4238: ** ^The sqlite3_result_int64() interface sets the return value 4239: ** of the application-defined function to be the 64-bit signed integer 4240: ** value given in the 2nd argument. 4241: ** 4242: ** ^The sqlite3_result_null() interface sets the return value 4243: ** of the application-defined function to be NULL. 4244: ** 4245: ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4246: ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4247: ** set the return value of the application-defined function to be 4248: ** a text string which is represented as UTF-8, UTF-16 native byte order, 4249: ** UTF-16 little endian, or UTF-16 big endian, respectively. 4250: ** ^SQLite takes the text result from the application from 4251: ** the 2nd parameter of the sqlite3_result_text* interfaces. 4252: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4253: ** is negative, then SQLite takes result text from the 2nd parameter 4254: ** through the first zero character. 4255: ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4256: ** is non-negative, then as many bytes (not characters) of the text 4257: ** pointed to by the 2nd parameter are taken as the application-defined 4258: ** function result. If the 3rd parameter is non-negative, then it 4259: ** must be the byte offset into the string where the NUL terminator would 4260: ** appear if the string where NUL terminated. If any NUL characters occur 4261: ** in the string at a byte offset that is less than the value of the 3rd 4262: ** parameter, then the resulting string will contain embedded NULs and the 4263: ** result of expressions operating on strings with embedded NULs is undefined. 4264: ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4265: ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4266: ** function as the destructor on the text or BLOB result when it has 4267: ** finished using that result. 4268: ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4269: ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4270: ** assumes that the text or BLOB result is in constant space and does not 4271: ** copy the content of the parameter nor call a destructor on the content 4272: ** when it has finished using that result. 4273: ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4274: ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4275: ** then SQLite makes a copy of the result into space obtained from 4276: ** from [sqlite3_malloc()] before it returns. 4277: ** 4278: ** ^The sqlite3_result_value() interface sets the result of 4279: ** the application-defined function to be a copy the 4280: ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4281: ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4282: ** so that the [sqlite3_value] specified in the parameter may change or 4283: ** be deallocated after sqlite3_result_value() returns without harm. 4284: ** ^A [protected sqlite3_value] object may always be used where an 4285: ** [unprotected sqlite3_value] object is required, so either 4286: ** kind of [sqlite3_value] object can be used with this interface. 4287: ** 4288: ** If these routines are called from within the different thread 4289: ** than the one containing the application-defined function that received 4290: ** the [sqlite3_context] pointer, the results are undefined. 4291: */ 4292: SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4293: SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4294: SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4295: SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4296: SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4297: SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4298: SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4299: SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4300: SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4301: SQLITE_API void sqlite3_result_null(sqlite3_context*); 4302: SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4303: SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4304: SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4305: SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4306: SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4307: SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4308: 4309: /* 4310: ** CAPI3REF: Define New Collating Sequences 4311: ** 4312: ** ^These functions add, remove, or modify a [collation] associated 4313: ** with the [database connection] specified as the first argument. 4314: ** 4315: ** ^The name of the collation is a UTF-8 string 4316: ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4317: ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4318: ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4319: ** considered to be the same name. 4320: ** 4321: ** ^(The third argument (eTextRep) must be one of the constants: 4322: ** <ul> 4323: ** <li> [SQLITE_UTF8], 4324: ** <li> [SQLITE_UTF16LE], 4325: ** <li> [SQLITE_UTF16BE], 4326: ** <li> [SQLITE_UTF16], or 4327: ** <li> [SQLITE_UTF16_ALIGNED]. 4328: ** </ul>)^ 4329: ** ^The eTextRep argument determines the encoding of strings passed 4330: ** to the collating function callback, xCallback. 4331: ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4332: ** force strings to be UTF16 with native byte order. 4333: ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4334: ** on an even byte address. 4335: ** 4336: ** ^The fourth argument, pArg, is an application data pointer that is passed 4337: ** through as the first argument to the collating function callback. 4338: ** 4339: ** ^The fifth argument, xCallback, is a pointer to the collating function. 4340: ** ^Multiple collating functions can be registered using the same name but 4341: ** with different eTextRep parameters and SQLite will use whichever 4342: ** function requires the least amount of data transformation. 4343: ** ^If the xCallback argument is NULL then the collating function is 4344: ** deleted. ^When all collating functions having the same name are deleted, 4345: ** that collation is no longer usable. 4346: ** 4347: ** ^The collating function callback is invoked with a copy of the pArg 4348: ** application data pointer and with two strings in the encoding specified 4349: ** by the eTextRep argument. The collating function must return an 4350: ** integer that is negative, zero, or positive 4351: ** if the first string is less than, equal to, or greater than the second, 4352: ** respectively. A collating function must always return the same answer 4353: ** given the same inputs. If two or more collating functions are registered 4354: ** to the same collation name (using different eTextRep values) then all 4355: ** must give an equivalent answer when invoked with equivalent strings. 4356: ** The collating function must obey the following properties for all 4357: ** strings A, B, and C: 4358: ** 4359: ** <ol> 4360: ** <li> If A==B then B==A. 4361: ** <li> If A==B and B==C then A==C. 4362: ** <li> If A<B THEN B>A. 4363: ** <li> If A<B and B<C then A<C. 4364: ** </ol> 4365: ** 4366: ** If a collating function fails any of the above constraints and that 4367: ** collating function is registered and used, then the behavior of SQLite 4368: ** is undefined. 4369: ** 4370: ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4371: ** with the addition that the xDestroy callback is invoked on pArg when 4372: ** the collating function is deleted. 4373: ** ^Collating functions are deleted when they are overridden by later 4374: ** calls to the collation creation functions or when the 4375: ** [database connection] is closed using [sqlite3_close()]. 4376: ** 4377: ** ^The xDestroy callback is <u>not</u> called if the 4378: ** sqlite3_create_collation_v2() function fails. Applications that invoke 4379: ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4380: ** check the return code and dispose of the application data pointer 4381: ** themselves rather than expecting SQLite to deal with it for them. 4382: ** This is different from every other SQLite interface. The inconsistency 4383: ** is unfortunate but cannot be changed without breaking backwards 4384: ** compatibility. 4385: ** 4386: ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4387: */ 4388: SQLITE_API int sqlite3_create_collation( 4389: sqlite3*, 4390: const char *zName, 4391: int eTextRep, 4392: void *pArg, 4393: int(*xCompare)(void*,int,const void*,int,const void*) 4394: ); 4395: SQLITE_API int sqlite3_create_collation_v2( 4396: sqlite3*, 4397: const char *zName, 4398: int eTextRep, 4399: void *pArg, 4400: int(*xCompare)(void*,int,const void*,int,const void*), 4401: void(*xDestroy)(void*) 4402: ); 4403: SQLITE_API int sqlite3_create_collation16( 4404: sqlite3*, 4405: const void *zName, 4406: int eTextRep, 4407: void *pArg, 4408: int(*xCompare)(void*,int,const void*,int,const void*) 4409: ); 4410: 4411: /* 4412: ** CAPI3REF: Collation Needed Callbacks 4413: ** 4414: ** ^To avoid having to register all collation sequences before a database 4415: ** can be used, a single callback function may be registered with the 4416: ** [database connection] to be invoked whenever an undefined collation 4417: ** sequence is required. 4418: ** 4419: ** ^If the function is registered using the sqlite3_collation_needed() API, 4420: ** then it is passed the names of undefined collation sequences as strings 4421: ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4422: ** the names are passed as UTF-16 in machine native byte order. 4423: ** ^A call to either function replaces the existing collation-needed callback. 4424: ** 4425: ** ^(When the callback is invoked, the first argument passed is a copy 4426: ** of the second argument to sqlite3_collation_needed() or 4427: ** sqlite3_collation_needed16(). The second argument is the database 4428: ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4429: ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4430: ** sequence function required. The fourth parameter is the name of the 4431: ** required collation sequence.)^ 4432: ** 4433: ** The callback function should register the desired collation using 4434: ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4435: ** [sqlite3_create_collation_v2()]. 4436: */ 4437: SQLITE_API int sqlite3_collation_needed( 4438: sqlite3*, 4439: void*, 4440: void(*)(void*,sqlite3*,int eTextRep,const char*) 4441: ); 4442: SQLITE_API int sqlite3_collation_needed16( 4443: sqlite3*, 4444: void*, 4445: void(*)(void*,sqlite3*,int eTextRep,const void*) 4446: ); 4447: 4448: #ifdef SQLITE_HAS_CODEC 4449: /* 4450: ** Specify the key for an encrypted database. This routine should be 4451: ** called right after sqlite3_open(). 4452: ** 4453: ** The code to implement this API is not available in the public release 4454: ** of SQLite. 4455: */ 4456: SQLITE_API int sqlite3_key( 4457: sqlite3 *db, /* Database to be rekeyed */ 4458: const void *pKey, int nKey /* The key */ 4459: ); 4460: 4461: /* 4462: ** Change the key on an open database. If the current database is not 4463: ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4464: ** database is decrypted. 4465: ** 4466: ** The code to implement this API is not available in the public release 4467: ** of SQLite. 4468: */ 4469: SQLITE_API int sqlite3_rekey( 4470: sqlite3 *db, /* Database to be rekeyed */ 4471: const void *pKey, int nKey /* The new key */ 4472: ); 4473: 4474: /* 4475: ** Specify the activation key for a SEE database. Unless 4476: ** activated, none of the SEE routines will work. 4477: */ 4478: SQLITE_API void sqlite3_activate_see( 4479: const char *zPassPhrase /* Activation phrase */ 4480: ); 4481: #endif 4482: 4483: #ifdef SQLITE_ENABLE_CEROD 4484: /* 4485: ** Specify the activation key for a CEROD database. Unless 4486: ** activated, none of the CEROD routines will work. 4487: */ 4488: SQLITE_API void sqlite3_activate_cerod( 4489: const char *zPassPhrase /* Activation phrase */ 4490: ); 4491: #endif 4492: 4493: /* 4494: ** CAPI3REF: Suspend Execution For A Short Time 4495: ** 4496: ** The sqlite3_sleep() function causes the current thread to suspend execution 4497: ** for at least a number of milliseconds specified in its parameter. 4498: ** 4499: ** If the operating system does not support sleep requests with 4500: ** millisecond time resolution, then the time will be rounded up to 4501: ** the nearest second. The number of milliseconds of sleep actually 4502: ** requested from the operating system is returned. 4503: ** 4504: ** ^SQLite implements this interface by calling the xSleep() 4505: ** method of the default [sqlite3_vfs] object. If the xSleep() method 4506: ** of the default VFS is not implemented correctly, or not implemented at 4507: ** all, then the behavior of sqlite3_sleep() may deviate from the description 4508: ** in the previous paragraphs. 4509: */ 4510: SQLITE_API int sqlite3_sleep(int); 4511: 4512: /* 4513: ** CAPI3REF: Name Of The Folder Holding Temporary Files 4514: ** 4515: ** ^(If this global variable is made to point to a string which is 4516: ** the name of a folder (a.k.a. directory), then all temporary files 4517: ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4518: ** will be placed in that directory.)^ ^If this variable 4519: ** is a NULL pointer, then SQLite performs a search for an appropriate 4520: ** temporary file directory. 4521: ** 4522: ** It is not safe to read or modify this variable in more than one 4523: ** thread at a time. It is not safe to read or modify this variable 4524: ** if a [database connection] is being used at the same time in a separate 4525: ** thread. 4526: ** It is intended that this variable be set once 4527: ** as part of process initialization and before any SQLite interface 4528: ** routines have been called and that this variable remain unchanged 4529: ** thereafter. 4530: ** 4531: ** ^The [temp_store_directory pragma] may modify this variable and cause 4532: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4533: ** the [temp_store_directory pragma] always assumes that any string 4534: ** that this variable points to is held in memory obtained from 4535: ** [sqlite3_malloc] and the pragma may attempt to free that memory 4536: ** using [sqlite3_free]. 4537: ** Hence, if this variable is modified directly, either it should be 4538: ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4539: ** or else the use of the [temp_store_directory pragma] should be avoided. 1.3 ! misho 4540: ** ! 4541: ** <b>Note to Windows Runtime users:</b> The temporary directory must be set ! 4542: ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various ! 4543: ** features that require the use of temporary files may fail. Here is an ! 4544: ** example of how to do this using C++ with the Windows Runtime: ! 4545: ** ! 4546: ** <blockquote><pre> ! 4547: ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> ! 4548: ** TemporaryFolder->Path->Data(); ! 4549: ** char zPathBuf[MAX_PATH + 1]; ! 4550: ** memset(zPathBuf, 0, sizeof(zPathBuf)); ! 4551: ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), ! 4552: ** NULL, NULL); ! 4553: ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); ! 4554: ** </pre></blockquote> 1.2 misho 4555: */ 4556: SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4557: 4558: /* 1.3 ! misho 4559: ** CAPI3REF: Name Of The Folder Holding Database Files ! 4560: ** ! 4561: ** ^(If this global variable is made to point to a string which is ! 4562: ** the name of a folder (a.k.a. directory), then all database files ! 4563: ** specified with a relative pathname and created or accessed by ! 4564: ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed ! 4565: ** to be relative to that directory.)^ ^If this variable is a NULL ! 4566: ** pointer, then SQLite assumes that all database files specified ! 4567: ** with a relative pathname are relative to the current directory ! 4568: ** for the process. Only the windows VFS makes use of this global ! 4569: ** variable; it is ignored by the unix VFS. ! 4570: ** ! 4571: ** Changing the value of this variable while a database connection is ! 4572: ** open can result in a corrupt database. ! 4573: ** ! 4574: ** It is not safe to read or modify this variable in more than one ! 4575: ** thread at a time. It is not safe to read or modify this variable ! 4576: ** if a [database connection] is being used at the same time in a separate ! 4577: ** thread. ! 4578: ** It is intended that this variable be set once ! 4579: ** as part of process initialization and before any SQLite interface ! 4580: ** routines have been called and that this variable remain unchanged ! 4581: ** thereafter. ! 4582: ** ! 4583: ** ^The [data_store_directory pragma] may modify this variable and cause ! 4584: ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, ! 4585: ** the [data_store_directory pragma] always assumes that any string ! 4586: ** that this variable points to is held in memory obtained from ! 4587: ** [sqlite3_malloc] and the pragma may attempt to free that memory ! 4588: ** using [sqlite3_free]. ! 4589: ** Hence, if this variable is modified directly, either it should be ! 4590: ** made NULL or made to point to memory obtained from [sqlite3_malloc] ! 4591: ** or else the use of the [data_store_directory pragma] should be avoided. ! 4592: */ ! 4593: SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; ! 4594: ! 4595: /* 1.2 misho 4596: ** CAPI3REF: Test For Auto-Commit Mode 4597: ** KEYWORDS: {autocommit mode} 4598: ** 4599: ** ^The sqlite3_get_autocommit() interface returns non-zero or 4600: ** zero if the given database connection is or is not in autocommit mode, 4601: ** respectively. ^Autocommit mode is on by default. 4602: ** ^Autocommit mode is disabled by a [BEGIN] statement. 4603: ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4604: ** 4605: ** If certain kinds of errors occur on a statement within a multi-statement 4606: ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4607: ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4608: ** transaction might be rolled back automatically. The only way to 4609: ** find out whether SQLite automatically rolled back the transaction after 4610: ** an error is to use this function. 4611: ** 4612: ** If another thread changes the autocommit status of the database 4613: ** connection while this routine is running, then the return value 4614: ** is undefined. 4615: */ 4616: SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4617: 4618: /* 4619: ** CAPI3REF: Find The Database Handle Of A Prepared Statement 4620: ** 4621: ** ^The sqlite3_db_handle interface returns the [database connection] handle 4622: ** to which a [prepared statement] belongs. ^The [database connection] 4623: ** returned by sqlite3_db_handle is the same [database connection] 4624: ** that was the first argument 4625: ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4626: ** create the statement in the first place. 4627: */ 4628: SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4629: 4630: /* 4631: ** CAPI3REF: Return The Filename For A Database Connection 4632: ** 4633: ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4634: ** associated with database N of connection D. ^The main database file 4635: ** has the name "main". If there is no attached database N on the database 4636: ** connection D, or if database N is a temporary or in-memory database, then 4637: ** a NULL pointer is returned. 4638: ** 4639: ** ^The filename returned by this function is the output of the 4640: ** xFullPathname method of the [VFS]. ^In other words, the filename 4641: ** will be an absolute pathname, even if the filename used 4642: ** to open the database originally was a URI or relative pathname. 4643: */ 4644: SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4645: 4646: /* 1.3 ! misho 4647: ** CAPI3REF: Determine if a database is read-only ! 4648: ** ! 4649: ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N ! 4650: ** of connection D is read-only, 0 if it is read/write, or -1 if N is not ! 4651: ** the name of a database on connection D. ! 4652: */ ! 4653: SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); ! 4654: ! 4655: /* 1.2 misho 4656: ** CAPI3REF: Find the next prepared statement 4657: ** 4658: ** ^This interface returns a pointer to the next [prepared statement] after 4659: ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4660: ** then this interface returns a pointer to the first prepared statement 4661: ** associated with the database connection pDb. ^If no prepared statement 4662: ** satisfies the conditions of this routine, it returns NULL. 4663: ** 4664: ** The [database connection] pointer D in a call to 4665: ** [sqlite3_next_stmt(D,S)] must refer to an open database 4666: ** connection and in particular must not be a NULL pointer. 4667: */ 4668: SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4669: 4670: /* 4671: ** CAPI3REF: Commit And Rollback Notification Callbacks 4672: ** 4673: ** ^The sqlite3_commit_hook() interface registers a callback 4674: ** function to be invoked whenever a transaction is [COMMIT | committed]. 4675: ** ^Any callback set by a previous call to sqlite3_commit_hook() 4676: ** for the same database connection is overridden. 4677: ** ^The sqlite3_rollback_hook() interface registers a callback 4678: ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4679: ** ^Any callback set by a previous call to sqlite3_rollback_hook() 4680: ** for the same database connection is overridden. 4681: ** ^The pArg argument is passed through to the callback. 4682: ** ^If the callback on a commit hook function returns non-zero, 4683: ** then the commit is converted into a rollback. 4684: ** 4685: ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4686: ** return the P argument from the previous call of the same function 4687: ** on the same [database connection] D, or NULL for 4688: ** the first call for each function on D. 4689: ** 4690: ** The commit and rollback hook callbacks are not reentrant. 4691: ** The callback implementation must not do anything that will modify 4692: ** the database connection that invoked the callback. Any actions 4693: ** to modify the database connection must be deferred until after the 4694: ** completion of the [sqlite3_step()] call that triggered the commit 4695: ** or rollback hook in the first place. 4696: ** Note that running any other SQL statements, including SELECT statements, 4697: ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4698: ** the database connections for the meaning of "modify" in this paragraph. 4699: ** 4700: ** ^Registering a NULL function disables the callback. 4701: ** 4702: ** ^When the commit hook callback routine returns zero, the [COMMIT] 4703: ** operation is allowed to continue normally. ^If the commit hook 4704: ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4705: ** ^The rollback hook is invoked on a rollback that results from a commit 4706: ** hook returning non-zero, just as it would be with any other rollback. 4707: ** 4708: ** ^For the purposes of this API, a transaction is said to have been 4709: ** rolled back if an explicit "ROLLBACK" statement is executed, or 4710: ** an error or constraint causes an implicit rollback to occur. 4711: ** ^The rollback callback is not invoked if a transaction is 4712: ** automatically rolled back because the database connection is closed. 4713: ** 4714: ** See also the [sqlite3_update_hook()] interface. 4715: */ 4716: SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4717: SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4718: 4719: /* 4720: ** CAPI3REF: Data Change Notification Callbacks 4721: ** 4722: ** ^The sqlite3_update_hook() interface registers a callback function 4723: ** with the [database connection] identified by the first argument 4724: ** to be invoked whenever a row is updated, inserted or deleted. 4725: ** ^Any callback set by a previous call to this function 4726: ** for the same database connection is overridden. 4727: ** 4728: ** ^The second argument is a pointer to the function to invoke when a 4729: ** row is updated, inserted or deleted. 4730: ** ^The first argument to the callback is a copy of the third argument 4731: ** to sqlite3_update_hook(). 4732: ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4733: ** or [SQLITE_UPDATE], depending on the operation that caused the callback 4734: ** to be invoked. 4735: ** ^The third and fourth arguments to the callback contain pointers to the 4736: ** database and table name containing the affected row. 4737: ** ^The final callback parameter is the [rowid] of the row. 4738: ** ^In the case of an update, this is the [rowid] after the update takes place. 4739: ** 4740: ** ^(The update hook is not invoked when internal system tables are 4741: ** modified (i.e. sqlite_master and sqlite_sequence).)^ 4742: ** 4743: ** ^In the current implementation, the update hook 4744: ** is not invoked when duplication rows are deleted because of an 4745: ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4746: ** invoked when rows are deleted using the [truncate optimization]. 4747: ** The exceptions defined in this paragraph might change in a future 4748: ** release of SQLite. 4749: ** 4750: ** The update hook implementation must not do anything that will modify 4751: ** the database connection that invoked the update hook. Any actions 4752: ** to modify the database connection must be deferred until after the 4753: ** completion of the [sqlite3_step()] call that triggered the update hook. 4754: ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4755: ** database connections for the meaning of "modify" in this paragraph. 4756: ** 4757: ** ^The sqlite3_update_hook(D,C,P) function 4758: ** returns the P argument from the previous call 4759: ** on the same [database connection] D, or NULL for 4760: ** the first call on D. 4761: ** 4762: ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4763: ** interfaces. 4764: */ 4765: SQLITE_API void *sqlite3_update_hook( 4766: sqlite3*, 4767: void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4768: void* 4769: ); 4770: 4771: /* 4772: ** CAPI3REF: Enable Or Disable Shared Pager Cache 4773: ** 4774: ** ^(This routine enables or disables the sharing of the database cache 4775: ** and schema data structures between [database connection | connections] 4776: ** to the same database. Sharing is enabled if the argument is true 4777: ** and disabled if the argument is false.)^ 4778: ** 4779: ** ^Cache sharing is enabled and disabled for an entire process. 4780: ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4781: ** sharing was enabled or disabled for each thread separately. 4782: ** 4783: ** ^(The cache sharing mode set by this interface effects all subsequent 4784: ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4785: ** Existing database connections continue use the sharing mode 4786: ** that was in effect at the time they were opened.)^ 4787: ** 4788: ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4789: ** successfully. An [error code] is returned otherwise.)^ 4790: ** 4791: ** ^Shared cache is disabled by default. But this might change in 4792: ** future releases of SQLite. Applications that care about shared 4793: ** cache setting should set it explicitly. 4794: ** 1.3 ! misho 4795: ** This interface is threadsafe on processors where writing a ! 4796: ** 32-bit integer is atomic. ! 4797: ** 1.2 misho 4798: ** See Also: [SQLite Shared-Cache Mode] 4799: */ 4800: SQLITE_API int sqlite3_enable_shared_cache(int); 4801: 4802: /* 4803: ** CAPI3REF: Attempt To Free Heap Memory 4804: ** 4805: ** ^The sqlite3_release_memory() interface attempts to free N bytes 4806: ** of heap memory by deallocating non-essential memory allocations 4807: ** held by the database library. Memory used to cache database 4808: ** pages to improve performance is an example of non-essential memory. 4809: ** ^sqlite3_release_memory() returns the number of bytes actually freed, 4810: ** which might be more or less than the amount requested. 4811: ** ^The sqlite3_release_memory() routine is a no-op returning zero 4812: ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4813: ** 4814: ** See also: [sqlite3_db_release_memory()] 4815: */ 4816: SQLITE_API int sqlite3_release_memory(int); 4817: 4818: /* 4819: ** CAPI3REF: Free Memory Used By A Database Connection 4820: ** 4821: ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4822: ** memory as possible from database connection D. Unlike the 4823: ** [sqlite3_release_memory()] interface, this interface is effect even 4824: ** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4825: ** omitted. 4826: ** 4827: ** See also: [sqlite3_release_memory()] 4828: */ 4829: SQLITE_API int sqlite3_db_release_memory(sqlite3*); 4830: 4831: /* 4832: ** CAPI3REF: Impose A Limit On Heap Size 4833: ** 4834: ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4835: ** soft limit on the amount of heap memory that may be allocated by SQLite. 4836: ** ^SQLite strives to keep heap memory utilization below the soft heap 4837: ** limit by reducing the number of pages held in the page cache 4838: ** as heap memory usages approaches the limit. 4839: ** ^The soft heap limit is "soft" because even though SQLite strives to stay 4840: ** below the limit, it will exceed the limit rather than generate 4841: ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4842: ** is advisory only. 4843: ** 4844: ** ^The return value from sqlite3_soft_heap_limit64() is the size of 4845: ** the soft heap limit prior to the call, or negative in the case of an 4846: ** error. ^If the argument N is negative 4847: ** then no change is made to the soft heap limit. Hence, the current 4848: ** size of the soft heap limit can be determined by invoking 4849: ** sqlite3_soft_heap_limit64() with a negative argument. 4850: ** 4851: ** ^If the argument N is zero then the soft heap limit is disabled. 4852: ** 4853: ** ^(The soft heap limit is not enforced in the current implementation 4854: ** if one or more of following conditions are true: 4855: ** 4856: ** <ul> 4857: ** <li> The soft heap limit is set to zero. 4858: ** <li> Memory accounting is disabled using a combination of the 4859: ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 4860: ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 4861: ** <li> An alternative page cache implementation is specified using 4862: ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 4863: ** <li> The page cache allocates from its own memory pool supplied 4864: ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 4865: ** from the heap. 4866: ** </ul>)^ 4867: ** 4868: ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 4869: ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 4870: ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 4871: ** the soft heap limit is enforced on every memory allocation. Without 4872: ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 4873: ** when memory is allocated by the page cache. Testing suggests that because 4874: ** the page cache is the predominate memory user in SQLite, most 4875: ** applications will achieve adequate soft heap limit enforcement without 4876: ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4877: ** 4878: ** The circumstances under which SQLite will enforce the soft heap limit may 4879: ** changes in future releases of SQLite. 4880: */ 4881: SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 4882: 4883: /* 4884: ** CAPI3REF: Deprecated Soft Heap Limit Interface 4885: ** DEPRECATED 4886: ** 4887: ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 4888: ** interface. This routine is provided for historical compatibility 4889: ** only. All new applications should use the 4890: ** [sqlite3_soft_heap_limit64()] interface rather than this one. 4891: */ 4892: SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 4893: 4894: 4895: /* 4896: ** CAPI3REF: Extract Metadata About A Column Of A Table 4897: ** 4898: ** ^This routine returns metadata about a specific column of a specific 4899: ** database table accessible using the [database connection] handle 4900: ** passed as the first function argument. 4901: ** 4902: ** ^The column is identified by the second, third and fourth parameters to 4903: ** this function. ^The second parameter is either the name of the database 4904: ** (i.e. "main", "temp", or an attached database) containing the specified 4905: ** table or NULL. ^If it is NULL, then all attached databases are searched 4906: ** for the table using the same algorithm used by the database engine to 4907: ** resolve unqualified table references. 4908: ** 4909: ** ^The third and fourth parameters to this function are the table and column 4910: ** name of the desired column, respectively. Neither of these parameters 4911: ** may be NULL. 4912: ** 4913: ** ^Metadata is returned by writing to the memory locations passed as the 5th 4914: ** and subsequent parameters to this function. ^Any of these arguments may be 4915: ** NULL, in which case the corresponding element of metadata is omitted. 4916: ** 4917: ** ^(<blockquote> 4918: ** <table border="1"> 4919: ** <tr><th> Parameter <th> Output<br>Type <th> Description 4920: ** 4921: ** <tr><td> 5th <td> const char* <td> Data type 4922: ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 4923: ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 4924: ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 4925: ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 4926: ** </table> 4927: ** </blockquote>)^ 4928: ** 4929: ** ^The memory pointed to by the character pointers returned for the 4930: ** declaration type and collation sequence is valid only until the next 4931: ** call to any SQLite API function. 4932: ** 4933: ** ^If the specified table is actually a view, an [error code] is returned. 4934: ** 4935: ** ^If the specified column is "rowid", "oid" or "_rowid_" and an 4936: ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 4937: ** parameters are set for the explicitly declared column. ^(If there is no 4938: ** explicitly declared [INTEGER PRIMARY KEY] column, then the output 4939: ** parameters are set as follows: 4940: ** 4941: ** <pre> 4942: ** data type: "INTEGER" 4943: ** collation sequence: "BINARY" 4944: ** not null: 0 4945: ** primary key: 1 4946: ** auto increment: 0 4947: ** </pre>)^ 4948: ** 4949: ** ^(This function may load one or more schemas from database files. If an 4950: ** error occurs during this process, or if the requested table or column 4951: ** cannot be found, an [error code] is returned and an error message left 4952: ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 4953: ** 4954: ** ^This API is only available if the library was compiled with the 4955: ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 4956: */ 4957: SQLITE_API int sqlite3_table_column_metadata( 4958: sqlite3 *db, /* Connection handle */ 4959: const char *zDbName, /* Database name or NULL */ 4960: const char *zTableName, /* Table name */ 4961: const char *zColumnName, /* Column name */ 4962: char const **pzDataType, /* OUTPUT: Declared data type */ 4963: char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4964: int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4965: int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4966: int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4967: ); 4968: 4969: /* 4970: ** CAPI3REF: Load An Extension 4971: ** 4972: ** ^This interface loads an SQLite extension library from the named file. 4973: ** 4974: ** ^The sqlite3_load_extension() interface attempts to load an 4975: ** SQLite extension library contained in the file zFile. 4976: ** 4977: ** ^The entry point is zProc. 4978: ** ^zProc may be 0, in which case the name of the entry point 4979: ** defaults to "sqlite3_extension_init". 4980: ** ^The sqlite3_load_extension() interface returns 4981: ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4982: ** ^If an error occurs and pzErrMsg is not 0, then the 4983: ** [sqlite3_load_extension()] interface shall attempt to 4984: ** fill *pzErrMsg with error message text stored in memory 4985: ** obtained from [sqlite3_malloc()]. The calling function 4986: ** should free this memory by calling [sqlite3_free()]. 4987: ** 4988: ** ^Extension loading must be enabled using 4989: ** [sqlite3_enable_load_extension()] prior to calling this API, 4990: ** otherwise an error will be returned. 4991: ** 4992: ** See also the [load_extension() SQL function]. 4993: */ 4994: SQLITE_API int sqlite3_load_extension( 4995: sqlite3 *db, /* Load the extension into this database connection */ 4996: const char *zFile, /* Name of the shared library containing extension */ 4997: const char *zProc, /* Entry point. Derived from zFile if 0 */ 4998: char **pzErrMsg /* Put error message here if not 0 */ 4999: ); 5000: 5001: /* 5002: ** CAPI3REF: Enable Or Disable Extension Loading 5003: ** 5004: ** ^So as not to open security holes in older applications that are 5005: ** unprepared to deal with extension loading, and as a means of disabling 5006: ** extension loading while evaluating user-entered SQL, the following API 5007: ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5008: ** 5009: ** ^Extension loading is off by default. See ticket #1863. 5010: ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5011: ** to turn extension loading on and call it with onoff==0 to turn 5012: ** it back off again. 5013: */ 5014: SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5015: 5016: /* 5017: ** CAPI3REF: Automatically Load Statically Linked Extensions 5018: ** 5019: ** ^This interface causes the xEntryPoint() function to be invoked for 5020: ** each new [database connection] that is created. The idea here is that 5021: ** xEntryPoint() is the entry point for a statically linked SQLite extension 5022: ** that is to be automatically loaded into all new database connections. 5023: ** 5024: ** ^(Even though the function prototype shows that xEntryPoint() takes 5025: ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5026: ** arguments and expects and integer result as if the signature of the 5027: ** entry point where as follows: 5028: ** 5029: ** <blockquote><pre> 5030: ** int xEntryPoint( 5031: ** sqlite3 *db, 5032: ** const char **pzErrMsg, 5033: ** const struct sqlite3_api_routines *pThunk 5034: ** ); 5035: ** </pre></blockquote>)^ 5036: ** 5037: ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5038: ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5039: ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5040: ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5041: ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5042: ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5043: ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5044: ** 5045: ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5046: ** on the list of automatic extensions is a harmless no-op. ^No entry point 5047: ** will be called more than once for each database connection that is opened. 5048: ** 5049: ** See also: [sqlite3_reset_auto_extension()]. 5050: */ 5051: SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5052: 5053: /* 5054: ** CAPI3REF: Reset Automatic Extension Loading 5055: ** 5056: ** ^This interface disables all automatic extensions previously 5057: ** registered using [sqlite3_auto_extension()]. 5058: */ 5059: SQLITE_API void sqlite3_reset_auto_extension(void); 5060: 5061: /* 5062: ** The interface to the virtual-table mechanism is currently considered 5063: ** to be experimental. The interface might change in incompatible ways. 5064: ** If this is a problem for you, do not use the interface at this time. 5065: ** 5066: ** When the virtual-table mechanism stabilizes, we will declare the 5067: ** interface fixed, support it indefinitely, and remove this comment. 5068: */ 5069: 5070: /* 5071: ** Structures used by the virtual table interface 5072: */ 5073: typedef struct sqlite3_vtab sqlite3_vtab; 5074: typedef struct sqlite3_index_info sqlite3_index_info; 5075: typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5076: typedef struct sqlite3_module sqlite3_module; 5077: 5078: /* 5079: ** CAPI3REF: Virtual Table Object 5080: ** KEYWORDS: sqlite3_module {virtual table module} 5081: ** 5082: ** This structure, sometimes called a "virtual table module", 5083: ** defines the implementation of a [virtual tables]. 5084: ** This structure consists mostly of methods for the module. 5085: ** 5086: ** ^A virtual table module is created by filling in a persistent 5087: ** instance of this structure and passing a pointer to that instance 5088: ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5089: ** ^The registration remains valid until it is replaced by a different 5090: ** module or until the [database connection] closes. The content 5091: ** of this structure must not change while it is registered with 5092: ** any database connection. 5093: */ 5094: struct sqlite3_module { 5095: int iVersion; 5096: int (*xCreate)(sqlite3*, void *pAux, 5097: int argc, const char *const*argv, 5098: sqlite3_vtab **ppVTab, char**); 5099: int (*xConnect)(sqlite3*, void *pAux, 5100: int argc, const char *const*argv, 5101: sqlite3_vtab **ppVTab, char**); 5102: int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5103: int (*xDisconnect)(sqlite3_vtab *pVTab); 5104: int (*xDestroy)(sqlite3_vtab *pVTab); 5105: int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5106: int (*xClose)(sqlite3_vtab_cursor*); 5107: int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5108: int argc, sqlite3_value **argv); 5109: int (*xNext)(sqlite3_vtab_cursor*); 5110: int (*xEof)(sqlite3_vtab_cursor*); 5111: int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5112: int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5113: int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5114: int (*xBegin)(sqlite3_vtab *pVTab); 5115: int (*xSync)(sqlite3_vtab *pVTab); 5116: int (*xCommit)(sqlite3_vtab *pVTab); 5117: int (*xRollback)(sqlite3_vtab *pVTab); 5118: int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5119: void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5120: void **ppArg); 5121: int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5122: /* The methods above are in version 1 of the sqlite_module object. Those 5123: ** below are for version 2 and greater. */ 5124: int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5125: int (*xRelease)(sqlite3_vtab *pVTab, int); 5126: int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5127: }; 5128: 5129: /* 5130: ** CAPI3REF: Virtual Table Indexing Information 5131: ** KEYWORDS: sqlite3_index_info 5132: ** 5133: ** The sqlite3_index_info structure and its substructures is used as part 5134: ** of the [virtual table] interface to 5135: ** pass information into and receive the reply from the [xBestIndex] 5136: ** method of a [virtual table module]. The fields under **Inputs** are the 5137: ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5138: ** results into the **Outputs** fields. 5139: ** 5140: ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5141: ** 5142: ** <blockquote>column OP expr</blockquote> 5143: ** 5144: ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5145: ** stored in aConstraint[].op using one of the 5146: ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5147: ** ^(The index of the column is stored in 5148: ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5149: ** expr on the right-hand side can be evaluated (and thus the constraint 5150: ** is usable) and false if it cannot.)^ 5151: ** 5152: ** ^The optimizer automatically inverts terms of the form "expr OP column" 5153: ** and makes other simplifications to the WHERE clause in an attempt to 5154: ** get as many WHERE clause terms into the form shown above as possible. 5155: ** ^The aConstraint[] array only reports WHERE clause terms that are 5156: ** relevant to the particular virtual table being queried. 5157: ** 5158: ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5159: ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5160: ** 5161: ** The [xBestIndex] method must fill aConstraintUsage[] with information 5162: ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5163: ** the right-hand side of the corresponding aConstraint[] is evaluated 5164: ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5165: ** is true, then the constraint is assumed to be fully handled by the 5166: ** virtual table and is not checked again by SQLite.)^ 5167: ** 5168: ** ^The idxNum and idxPtr values are recorded and passed into the 5169: ** [xFilter] method. 5170: ** ^[sqlite3_free()] is used to free idxPtr if and only if 5171: ** needToFreeIdxPtr is true. 5172: ** 5173: ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5174: ** the correct order to satisfy the ORDER BY clause so that no separate 5175: ** sorting step is required. 5176: ** 5177: ** ^The estimatedCost value is an estimate of the cost of doing the 5178: ** particular lookup. A full scan of a table with N entries should have 5179: ** a cost of N. A binary search of a table of N entries should have a 5180: ** cost of approximately log(N). 5181: */ 5182: struct sqlite3_index_info { 5183: /* Inputs */ 5184: int nConstraint; /* Number of entries in aConstraint */ 5185: struct sqlite3_index_constraint { 5186: int iColumn; /* Column on left-hand side of constraint */ 5187: unsigned char op; /* Constraint operator */ 5188: unsigned char usable; /* True if this constraint is usable */ 5189: int iTermOffset; /* Used internally - xBestIndex should ignore */ 5190: } *aConstraint; /* Table of WHERE clause constraints */ 5191: int nOrderBy; /* Number of terms in the ORDER BY clause */ 5192: struct sqlite3_index_orderby { 5193: int iColumn; /* Column number */ 5194: unsigned char desc; /* True for DESC. False for ASC. */ 5195: } *aOrderBy; /* The ORDER BY clause */ 5196: /* Outputs */ 5197: struct sqlite3_index_constraint_usage { 5198: int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5199: unsigned char omit; /* Do not code a test for this constraint */ 5200: } *aConstraintUsage; 5201: int idxNum; /* Number used to identify the index */ 5202: char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5203: int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5204: int orderByConsumed; /* True if output is already ordered */ 5205: double estimatedCost; /* Estimated cost of using this index */ 5206: }; 5207: 5208: /* 5209: ** CAPI3REF: Virtual Table Constraint Operator Codes 5210: ** 5211: ** These macros defined the allowed values for the 5212: ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5213: ** an operator that is part of a constraint term in the wHERE clause of 5214: ** a query that uses a [virtual table]. 5215: */ 5216: #define SQLITE_INDEX_CONSTRAINT_EQ 2 5217: #define SQLITE_INDEX_CONSTRAINT_GT 4 5218: #define SQLITE_INDEX_CONSTRAINT_LE 8 5219: #define SQLITE_INDEX_CONSTRAINT_LT 16 5220: #define SQLITE_INDEX_CONSTRAINT_GE 32 5221: #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5222: 5223: /* 5224: ** CAPI3REF: Register A Virtual Table Implementation 5225: ** 5226: ** ^These routines are used to register a new [virtual table module] name. 5227: ** ^Module names must be registered before 5228: ** creating a new [virtual table] using the module and before using a 5229: ** preexisting [virtual table] for the module. 5230: ** 5231: ** ^The module name is registered on the [database connection] specified 5232: ** by the first parameter. ^The name of the module is given by the 5233: ** second parameter. ^The third parameter is a pointer to 5234: ** the implementation of the [virtual table module]. ^The fourth 5235: ** parameter is an arbitrary client data pointer that is passed through 5236: ** into the [xCreate] and [xConnect] methods of the virtual table module 5237: ** when a new virtual table is be being created or reinitialized. 5238: ** 5239: ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5240: ** is a pointer to a destructor for the pClientData. ^SQLite will 5241: ** invoke the destructor function (if it is not NULL) when SQLite 5242: ** no longer needs the pClientData pointer. ^The destructor will also 5243: ** be invoked if the call to sqlite3_create_module_v2() fails. 5244: ** ^The sqlite3_create_module() 5245: ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5246: ** destructor. 5247: */ 5248: SQLITE_API int sqlite3_create_module( 5249: sqlite3 *db, /* SQLite connection to register module with */ 5250: const char *zName, /* Name of the module */ 5251: const sqlite3_module *p, /* Methods for the module */ 5252: void *pClientData /* Client data for xCreate/xConnect */ 5253: ); 5254: SQLITE_API int sqlite3_create_module_v2( 5255: sqlite3 *db, /* SQLite connection to register module with */ 5256: const char *zName, /* Name of the module */ 5257: const sqlite3_module *p, /* Methods for the module */ 5258: void *pClientData, /* Client data for xCreate/xConnect */ 5259: void(*xDestroy)(void*) /* Module destructor function */ 5260: ); 5261: 5262: /* 5263: ** CAPI3REF: Virtual Table Instance Object 5264: ** KEYWORDS: sqlite3_vtab 5265: ** 5266: ** Every [virtual table module] implementation uses a subclass 5267: ** of this object to describe a particular instance 5268: ** of the [virtual table]. Each subclass will 5269: ** be tailored to the specific needs of the module implementation. 5270: ** The purpose of this superclass is to define certain fields that are 5271: ** common to all module implementations. 5272: ** 5273: ** ^Virtual tables methods can set an error message by assigning a 5274: ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5275: ** take care that any prior string is freed by a call to [sqlite3_free()] 5276: ** prior to assigning a new string to zErrMsg. ^After the error message 5277: ** is delivered up to the client application, the string will be automatically 5278: ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5279: */ 5280: struct sqlite3_vtab { 5281: const sqlite3_module *pModule; /* The module for this virtual table */ 5282: int nRef; /* NO LONGER USED */ 5283: char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5284: /* Virtual table implementations will typically add additional fields */ 5285: }; 5286: 5287: /* 5288: ** CAPI3REF: Virtual Table Cursor Object 5289: ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5290: ** 5291: ** Every [virtual table module] implementation uses a subclass of the 5292: ** following structure to describe cursors that point into the 5293: ** [virtual table] and are used 5294: ** to loop through the virtual table. Cursors are created using the 5295: ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5296: ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5297: ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5298: ** of the module. Each module implementation will define 5299: ** the content of a cursor structure to suit its own needs. 5300: ** 5301: ** This superclass exists in order to define fields of the cursor that 5302: ** are common to all implementations. 5303: */ 5304: struct sqlite3_vtab_cursor { 5305: sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5306: /* Virtual table implementations will typically add additional fields */ 5307: }; 5308: 5309: /* 5310: ** CAPI3REF: Declare The Schema Of A Virtual Table 5311: ** 5312: ** ^The [xCreate] and [xConnect] methods of a 5313: ** [virtual table module] call this interface 5314: ** to declare the format (the names and datatypes of the columns) of 5315: ** the virtual tables they implement. 5316: */ 5317: SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5318: 5319: /* 5320: ** CAPI3REF: Overload A Function For A Virtual Table 5321: ** 5322: ** ^(Virtual tables can provide alternative implementations of functions 5323: ** using the [xFindFunction] method of the [virtual table module]. 5324: ** But global versions of those functions 5325: ** must exist in order to be overloaded.)^ 5326: ** 5327: ** ^(This API makes sure a global version of a function with a particular 5328: ** name and number of parameters exists. If no such function exists 5329: ** before this API is called, a new function is created.)^ ^The implementation 5330: ** of the new function always causes an exception to be thrown. So 5331: ** the new function is not good for anything by itself. Its only 5332: ** purpose is to be a placeholder function that can be overloaded 5333: ** by a [virtual table]. 5334: */ 5335: SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5336: 5337: /* 5338: ** The interface to the virtual-table mechanism defined above (back up 5339: ** to a comment remarkably similar to this one) is currently considered 5340: ** to be experimental. The interface might change in incompatible ways. 5341: ** If this is a problem for you, do not use the interface at this time. 5342: ** 5343: ** When the virtual-table mechanism stabilizes, we will declare the 5344: ** interface fixed, support it indefinitely, and remove this comment. 5345: */ 5346: 5347: /* 5348: ** CAPI3REF: A Handle To An Open BLOB 5349: ** KEYWORDS: {BLOB handle} {BLOB handles} 5350: ** 5351: ** An instance of this object represents an open BLOB on which 5352: ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5353: ** ^Objects of this type are created by [sqlite3_blob_open()] 5354: ** and destroyed by [sqlite3_blob_close()]. 5355: ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5356: ** can be used to read or write small subsections of the BLOB. 5357: ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5358: */ 5359: typedef struct sqlite3_blob sqlite3_blob; 5360: 5361: /* 5362: ** CAPI3REF: Open A BLOB For Incremental I/O 5363: ** 5364: ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5365: ** in row iRow, column zColumn, table zTable in database zDb; 5366: ** in other words, the same BLOB that would be selected by: 5367: ** 5368: ** <pre> 5369: ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5370: ** </pre>)^ 5371: ** 5372: ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5373: ** and write access. ^If it is zero, the BLOB is opened for read access. 5374: ** ^It is not possible to open a column that is part of an index or primary 5375: ** key for writing. ^If [foreign key constraints] are enabled, it is 5376: ** not possible to open a column that is part of a [child key] for writing. 5377: ** 5378: ** ^Note that the database name is not the filename that contains 5379: ** the database but rather the symbolic name of the database that 5380: ** appears after the AS keyword when the database is connected using [ATTACH]. 5381: ** ^For the main database file, the database name is "main". 5382: ** ^For TEMP tables, the database name is "temp". 5383: ** 5384: ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5385: ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5386: ** to be a null pointer.)^ 5387: ** ^This function sets the [database connection] error code and message 5388: ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5389: ** functions. ^Note that the *ppBlob variable is always initialized in a 5390: ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5391: ** regardless of the success or failure of this routine. 5392: ** 5393: ** ^(If the row that a BLOB handle points to is modified by an 5394: ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5395: ** then the BLOB handle is marked as "expired". 5396: ** This is true if any column of the row is changed, even a column 5397: ** other than the one the BLOB handle is open on.)^ 5398: ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5399: ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5400: ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5401: ** rolled back by the expiration of the BLOB. Such changes will eventually 5402: ** commit if the transaction continues to completion.)^ 5403: ** 5404: ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5405: ** the opened blob. ^The size of a blob may not be changed by this 5406: ** interface. Use the [UPDATE] SQL command to change the size of a 5407: ** blob. 5408: ** 5409: ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5410: ** and the built-in [zeroblob] SQL function can be used, if desired, 5411: ** to create an empty, zero-filled blob in which to read or write using 5412: ** this interface. 5413: ** 5414: ** To avoid a resource leak, every open [BLOB handle] should eventually 5415: ** be released by a call to [sqlite3_blob_close()]. 5416: */ 5417: SQLITE_API int sqlite3_blob_open( 5418: sqlite3*, 5419: const char *zDb, 5420: const char *zTable, 5421: const char *zColumn, 5422: sqlite3_int64 iRow, 5423: int flags, 5424: sqlite3_blob **ppBlob 5425: ); 5426: 5427: /* 5428: ** CAPI3REF: Move a BLOB Handle to a New Row 5429: ** 5430: ** ^This function is used to move an existing blob handle so that it points 5431: ** to a different row of the same database table. ^The new row is identified 5432: ** by the rowid value passed as the second argument. Only the row can be 5433: ** changed. ^The database, table and column on which the blob handle is open 5434: ** remain the same. Moving an existing blob handle to a new row can be 5435: ** faster than closing the existing handle and opening a new one. 5436: ** 5437: ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5438: ** it must exist and there must be either a blob or text value stored in 5439: ** the nominated column.)^ ^If the new row is not present in the table, or if 5440: ** it does not contain a blob or text value, or if another error occurs, an 5441: ** SQLite error code is returned and the blob handle is considered aborted. 5442: ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5443: ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5444: ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5445: ** always returns zero. 5446: ** 5447: ** ^This function sets the database handle error code and message. 5448: */ 5449: SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5450: 5451: /* 5452: ** CAPI3REF: Close A BLOB Handle 5453: ** 5454: ** ^Closes an open [BLOB handle]. 5455: ** 5456: ** ^Closing a BLOB shall cause the current transaction to commit 5457: ** if there are no other BLOBs, no pending prepared statements, and the 5458: ** database connection is in [autocommit mode]. 5459: ** ^If any writes were made to the BLOB, they might be held in cache 5460: ** until the close operation if they will fit. 5461: ** 5462: ** ^(Closing the BLOB often forces the changes 5463: ** out to disk and so if any I/O errors occur, they will likely occur 5464: ** at the time when the BLOB is closed. Any errors that occur during 5465: ** closing are reported as a non-zero return value.)^ 5466: ** 5467: ** ^(The BLOB is closed unconditionally. Even if this routine returns 5468: ** an error code, the BLOB is still closed.)^ 5469: ** 5470: ** ^Calling this routine with a null pointer (such as would be returned 5471: ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5472: */ 5473: SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 5474: 5475: /* 5476: ** CAPI3REF: Return The Size Of An Open BLOB 5477: ** 5478: ** ^Returns the size in bytes of the BLOB accessible via the 5479: ** successfully opened [BLOB handle] in its only argument. ^The 5480: ** incremental blob I/O routines can only read or overwriting existing 5481: ** blob content; they cannot change the size of a blob. 5482: ** 5483: ** This routine only works on a [BLOB handle] which has been created 5484: ** by a prior successful call to [sqlite3_blob_open()] and which has not 5485: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5486: ** to this routine results in undefined and probably undesirable behavior. 5487: */ 5488: SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 5489: 5490: /* 5491: ** CAPI3REF: Read Data From A BLOB Incrementally 5492: ** 5493: ** ^(This function is used to read data from an open [BLOB handle] into a 5494: ** caller-supplied buffer. N bytes of data are copied into buffer Z 5495: ** from the open BLOB, starting at offset iOffset.)^ 5496: ** 5497: ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5498: ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5499: ** less than zero, [SQLITE_ERROR] is returned and no data is read. 5500: ** ^The size of the blob (and hence the maximum value of N+iOffset) 5501: ** can be determined using the [sqlite3_blob_bytes()] interface. 5502: ** 5503: ** ^An attempt to read from an expired [BLOB handle] fails with an 5504: ** error code of [SQLITE_ABORT]. 5505: ** 5506: ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5507: ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5508: ** 5509: ** This routine only works on a [BLOB handle] which has been created 5510: ** by a prior successful call to [sqlite3_blob_open()] and which has not 5511: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5512: ** to this routine results in undefined and probably undesirable behavior. 5513: ** 5514: ** See also: [sqlite3_blob_write()]. 5515: */ 5516: SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5517: 5518: /* 5519: ** CAPI3REF: Write Data Into A BLOB Incrementally 5520: ** 5521: ** ^This function is used to write data into an open [BLOB handle] from a 5522: ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5523: ** into the open BLOB, starting at offset iOffset. 5524: ** 5525: ** ^If the [BLOB handle] passed as the first argument was not opened for 5526: ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5527: ** this function returns [SQLITE_READONLY]. 5528: ** 5529: ** ^This function may only modify the contents of the BLOB; it is 5530: ** not possible to increase the size of a BLOB using this API. 5531: ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5532: ** [SQLITE_ERROR] is returned and no data is written. ^If N is 5533: ** less than zero [SQLITE_ERROR] is returned and no data is written. 5534: ** The size of the BLOB (and hence the maximum value of N+iOffset) 5535: ** can be determined using the [sqlite3_blob_bytes()] interface. 5536: ** 5537: ** ^An attempt to write to an expired [BLOB handle] fails with an 5538: ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5539: ** before the [BLOB handle] expired are not rolled back by the 5540: ** expiration of the handle, though of course those changes might 5541: ** have been overwritten by the statement that expired the BLOB handle 5542: ** or by other independent statements. 5543: ** 5544: ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5545: ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5546: ** 5547: ** This routine only works on a [BLOB handle] which has been created 5548: ** by a prior successful call to [sqlite3_blob_open()] and which has not 5549: ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5550: ** to this routine results in undefined and probably undesirable behavior. 5551: ** 5552: ** See also: [sqlite3_blob_read()]. 5553: */ 5554: SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5555: 5556: /* 5557: ** CAPI3REF: Virtual File System Objects 5558: ** 5559: ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5560: ** that SQLite uses to interact 5561: ** with the underlying operating system. Most SQLite builds come with a 5562: ** single default VFS that is appropriate for the host computer. 5563: ** New VFSes can be registered and existing VFSes can be unregistered. 5564: ** The following interfaces are provided. 5565: ** 5566: ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5567: ** ^Names are case sensitive. 5568: ** ^Names are zero-terminated UTF-8 strings. 5569: ** ^If there is no match, a NULL pointer is returned. 5570: ** ^If zVfsName is NULL then the default VFS is returned. 5571: ** 5572: ** ^New VFSes are registered with sqlite3_vfs_register(). 5573: ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5574: ** ^The same VFS can be registered multiple times without injury. 5575: ** ^To make an existing VFS into the default VFS, register it again 5576: ** with the makeDflt flag set. If two different VFSes with the 5577: ** same name are registered, the behavior is undefined. If a 5578: ** VFS is registered with a name that is NULL or an empty string, 5579: ** then the behavior is undefined. 5580: ** 5581: ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5582: ** ^(If the default VFS is unregistered, another VFS is chosen as 5583: ** the default. The choice for the new VFS is arbitrary.)^ 5584: */ 5585: SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5586: SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5587: SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5588: 5589: /* 5590: ** CAPI3REF: Mutexes 5591: ** 5592: ** The SQLite core uses these routines for thread 5593: ** synchronization. Though they are intended for internal 5594: ** use by SQLite, code that links against SQLite is 5595: ** permitted to use any of these routines. 5596: ** 5597: ** The SQLite source code contains multiple implementations 5598: ** of these mutex routines. An appropriate implementation 5599: ** is selected automatically at compile-time. ^(The following 5600: ** implementations are available in the SQLite core: 5601: ** 5602: ** <ul> 5603: ** <li> SQLITE_MUTEX_PTHREADS 5604: ** <li> SQLITE_MUTEX_W32 5605: ** <li> SQLITE_MUTEX_NOOP 5606: ** </ul>)^ 5607: ** 5608: ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5609: ** that does no real locking and is appropriate for use in 1.3 ! misho 5610: ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and ! 5611: ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix ! 5612: ** and Windows. 1.2 misho 5613: ** 5614: ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5615: ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5616: ** implementation is included with the library. In this case the 5617: ** application must supply a custom mutex implementation using the 5618: ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5619: ** before calling sqlite3_initialize() or any other public sqlite3_ 5620: ** function that calls sqlite3_initialize().)^ 5621: ** 5622: ** ^The sqlite3_mutex_alloc() routine allocates a new 5623: ** mutex and returns a pointer to it. ^If it returns NULL 5624: ** that means that a mutex could not be allocated. ^SQLite 5625: ** will unwind its stack and return an error. ^(The argument 5626: ** to sqlite3_mutex_alloc() is one of these integer constants: 5627: ** 5628: ** <ul> 5629: ** <li> SQLITE_MUTEX_FAST 5630: ** <li> SQLITE_MUTEX_RECURSIVE 5631: ** <li> SQLITE_MUTEX_STATIC_MASTER 5632: ** <li> SQLITE_MUTEX_STATIC_MEM 5633: ** <li> SQLITE_MUTEX_STATIC_MEM2 5634: ** <li> SQLITE_MUTEX_STATIC_PRNG 5635: ** <li> SQLITE_MUTEX_STATIC_LRU 5636: ** <li> SQLITE_MUTEX_STATIC_LRU2 5637: ** </ul>)^ 5638: ** 5639: ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5640: ** cause sqlite3_mutex_alloc() to create 5641: ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5642: ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5643: ** The mutex implementation does not need to make a distinction 5644: ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5645: ** not want to. ^SQLite will only request a recursive mutex in 5646: ** cases where it really needs one. ^If a faster non-recursive mutex 5647: ** implementation is available on the host platform, the mutex subsystem 5648: ** might return such a mutex in response to SQLITE_MUTEX_FAST. 5649: ** 5650: ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5651: ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5652: ** a pointer to a static preexisting mutex. ^Six static mutexes are 5653: ** used by the current version of SQLite. Future versions of SQLite 5654: ** may add additional static mutexes. Static mutexes are for internal 5655: ** use by SQLite only. Applications that use SQLite mutexes should 5656: ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5657: ** SQLITE_MUTEX_RECURSIVE. 5658: ** 5659: ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5660: ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5661: ** returns a different mutex on every call. ^But for the static 5662: ** mutex types, the same mutex is returned on every call that has 5663: ** the same type number. 5664: ** 5665: ** ^The sqlite3_mutex_free() routine deallocates a previously 5666: ** allocated dynamic mutex. ^SQLite is careful to deallocate every 5667: ** dynamic mutex that it allocates. The dynamic mutexes must not be in 5668: ** use when they are deallocated. Attempting to deallocate a static 5669: ** mutex results in undefined behavior. ^SQLite never deallocates 5670: ** a static mutex. 5671: ** 5672: ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5673: ** to enter a mutex. ^If another thread is already within the mutex, 5674: ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5675: ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5676: ** upon successful entry. ^(Mutexes created using 5677: ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5678: ** In such cases the, 5679: ** mutex must be exited an equal number of times before another thread 5680: ** can enter.)^ ^(If the same thread tries to enter any other 5681: ** kind of mutex more than once, the behavior is undefined. 5682: ** SQLite will never exhibit 5683: ** such behavior in its own use of mutexes.)^ 5684: ** 5685: ** ^(Some systems (for example, Windows 95) do not support the operation 5686: ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5687: ** will always return SQLITE_BUSY. The SQLite core only ever uses 5688: ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5689: ** 5690: ** ^The sqlite3_mutex_leave() routine exits a mutex that was 5691: ** previously entered by the same thread. ^(The behavior 5692: ** is undefined if the mutex is not currently entered by the 5693: ** calling thread or is not currently allocated. SQLite will 5694: ** never do either.)^ 5695: ** 5696: ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5697: ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5698: ** behave as no-ops. 5699: ** 5700: ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5701: */ 5702: SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5703: SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5704: SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5705: SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5706: SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5707: 5708: /* 5709: ** CAPI3REF: Mutex Methods Object 5710: ** 5711: ** An instance of this structure defines the low-level routines 5712: ** used to allocate and use mutexes. 5713: ** 5714: ** Usually, the default mutex implementations provided by SQLite are 5715: ** sufficient, however the user has the option of substituting a custom 5716: ** implementation for specialized deployments or systems for which SQLite 5717: ** does not provide a suitable implementation. In this case, the user 5718: ** creates and populates an instance of this structure to pass 5719: ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5720: ** Additionally, an instance of this structure can be used as an 5721: ** output variable when querying the system for the current mutex 5722: ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5723: ** 5724: ** ^The xMutexInit method defined by this structure is invoked as 5725: ** part of system initialization by the sqlite3_initialize() function. 5726: ** ^The xMutexInit routine is called by SQLite exactly once for each 5727: ** effective call to [sqlite3_initialize()]. 5728: ** 5729: ** ^The xMutexEnd method defined by this structure is invoked as 5730: ** part of system shutdown by the sqlite3_shutdown() function. The 5731: ** implementation of this method is expected to release all outstanding 5732: ** resources obtained by the mutex methods implementation, especially 5733: ** those obtained by the xMutexInit method. ^The xMutexEnd() 5734: ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5735: ** 5736: ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5737: ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5738: ** xMutexNotheld) implement the following interfaces (respectively): 5739: ** 5740: ** <ul> 5741: ** <li> [sqlite3_mutex_alloc()] </li> 5742: ** <li> [sqlite3_mutex_free()] </li> 5743: ** <li> [sqlite3_mutex_enter()] </li> 5744: ** <li> [sqlite3_mutex_try()] </li> 5745: ** <li> [sqlite3_mutex_leave()] </li> 5746: ** <li> [sqlite3_mutex_held()] </li> 5747: ** <li> [sqlite3_mutex_notheld()] </li> 5748: ** </ul>)^ 5749: ** 5750: ** The only difference is that the public sqlite3_XXX functions enumerated 5751: ** above silently ignore any invocations that pass a NULL pointer instead 5752: ** of a valid mutex handle. The implementations of the methods defined 5753: ** by this structure are not required to handle this case, the results 5754: ** of passing a NULL pointer instead of a valid mutex handle are undefined 5755: ** (i.e. it is acceptable to provide an implementation that segfaults if 5756: ** it is passed a NULL pointer). 5757: ** 5758: ** The xMutexInit() method must be threadsafe. ^It must be harmless to 5759: ** invoke xMutexInit() multiple times within the same process and without 5760: ** intervening calls to xMutexEnd(). Second and subsequent calls to 5761: ** xMutexInit() must be no-ops. 5762: ** 5763: ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5764: ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5765: ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5766: ** memory allocation for a fast or recursive mutex. 5767: ** 5768: ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5769: ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5770: ** If xMutexInit fails in any way, it is expected to clean up after itself 5771: ** prior to returning. 5772: */ 5773: typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5774: struct sqlite3_mutex_methods { 5775: int (*xMutexInit)(void); 5776: int (*xMutexEnd)(void); 5777: sqlite3_mutex *(*xMutexAlloc)(int); 5778: void (*xMutexFree)(sqlite3_mutex *); 5779: void (*xMutexEnter)(sqlite3_mutex *); 5780: int (*xMutexTry)(sqlite3_mutex *); 5781: void (*xMutexLeave)(sqlite3_mutex *); 5782: int (*xMutexHeld)(sqlite3_mutex *); 5783: int (*xMutexNotheld)(sqlite3_mutex *); 5784: }; 5785: 5786: /* 5787: ** CAPI3REF: Mutex Verification Routines 5788: ** 5789: ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5790: ** are intended for use inside assert() statements. ^The SQLite core 5791: ** never uses these routines except inside an assert() and applications 5792: ** are advised to follow the lead of the core. ^The SQLite core only 5793: ** provides implementations for these routines when it is compiled 5794: ** with the SQLITE_DEBUG flag. ^External mutex implementations 5795: ** are only required to provide these routines if SQLITE_DEBUG is 5796: ** defined and if NDEBUG is not defined. 5797: ** 5798: ** ^These routines should return true if the mutex in their argument 5799: ** is held or not held, respectively, by the calling thread. 5800: ** 5801: ** ^The implementation is not required to provide versions of these 5802: ** routines that actually work. If the implementation does not provide working 5803: ** versions of these routines, it should at least provide stubs that always 5804: ** return true so that one does not get spurious assertion failures. 5805: ** 5806: ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5807: ** the routine should return 1. This seems counter-intuitive since 5808: ** clearly the mutex cannot be held if it does not exist. But 5809: ** the reason the mutex does not exist is because the build is not 5810: ** using mutexes. And we do not want the assert() containing the 5811: ** call to sqlite3_mutex_held() to fail, so a non-zero return is 5812: ** the appropriate thing to do. ^The sqlite3_mutex_notheld() 5813: ** interface should also return 1 when given a NULL pointer. 5814: */ 5815: #ifndef NDEBUG 5816: SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 5817: SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 5818: #endif 5819: 5820: /* 5821: ** CAPI3REF: Mutex Types 5822: ** 5823: ** The [sqlite3_mutex_alloc()] interface takes a single argument 5824: ** which is one of these integer constants. 5825: ** 5826: ** The set of static mutexes may change from one SQLite release to the 5827: ** next. Applications that override the built-in mutex logic must be 5828: ** prepared to accommodate additional static mutexes. 5829: */ 5830: #define SQLITE_MUTEX_FAST 0 5831: #define SQLITE_MUTEX_RECURSIVE 1 5832: #define SQLITE_MUTEX_STATIC_MASTER 2 5833: #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5834: #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 5835: #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 5836: #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5837: #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5838: #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 5839: #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 5840: 5841: /* 5842: ** CAPI3REF: Retrieve the mutex for a database connection 5843: ** 5844: ** ^This interface returns a pointer the [sqlite3_mutex] object that 5845: ** serializes access to the [database connection] given in the argument 5846: ** when the [threading mode] is Serialized. 5847: ** ^If the [threading mode] is Single-thread or Multi-thread then this 5848: ** routine returns a NULL pointer. 5849: */ 5850: SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 5851: 5852: /* 5853: ** CAPI3REF: Low-Level Control Of Database Files 5854: ** 5855: ** ^The [sqlite3_file_control()] interface makes a direct call to the 5856: ** xFileControl method for the [sqlite3_io_methods] object associated 5857: ** with a particular database identified by the second argument. ^The 5858: ** name of the database is "main" for the main database or "temp" for the 5859: ** TEMP database, or the name that appears after the AS keyword for 5860: ** databases that are added using the [ATTACH] SQL command. 5861: ** ^A NULL pointer can be used in place of "main" to refer to the 5862: ** main database file. 5863: ** ^The third and fourth parameters to this routine 5864: ** are passed directly through to the second and third parameters of 5865: ** the xFileControl method. ^The return value of the xFileControl 5866: ** method becomes the return value of this routine. 5867: ** 5868: ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 5869: ** a pointer to the underlying [sqlite3_file] object to be written into 5870: ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 5871: ** case is a short-circuit path which does not actually invoke the 5872: ** underlying sqlite3_io_methods.xFileControl method. 5873: ** 5874: ** ^If the second parameter (zDbName) does not match the name of any 5875: ** open database file, then SQLITE_ERROR is returned. ^This error 5876: ** code is not remembered and will not be recalled by [sqlite3_errcode()] 5877: ** or [sqlite3_errmsg()]. The underlying xFileControl method might 5878: ** also return SQLITE_ERROR. There is no way to distinguish between 5879: ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5880: ** xFileControl method. 5881: ** 5882: ** See also: [SQLITE_FCNTL_LOCKSTATE] 5883: */ 5884: SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5885: 5886: /* 5887: ** CAPI3REF: Testing Interface 5888: ** 5889: ** ^The sqlite3_test_control() interface is used to read out internal 5890: ** state of SQLite and to inject faults into SQLite for testing 5891: ** purposes. ^The first parameter is an operation code that determines 5892: ** the number, meaning, and operation of all subsequent parameters. 5893: ** 5894: ** This interface is not for use by applications. It exists solely 5895: ** for verifying the correct operation of the SQLite library. Depending 5896: ** on how the SQLite library is compiled, this interface might not exist. 5897: ** 5898: ** The details of the operation codes, their meanings, the parameters 5899: ** they take, and what they do are all subject to change without notice. 5900: ** Unlike most of the SQLite API, this function is not guaranteed to 5901: ** operate consistently from one release to the next. 5902: */ 5903: SQLITE_API int sqlite3_test_control(int op, ...); 5904: 5905: /* 5906: ** CAPI3REF: Testing Interface Operation Codes 5907: ** 5908: ** These constants are the valid operation code parameters used 5909: ** as the first argument to [sqlite3_test_control()]. 5910: ** 5911: ** These parameters and their meanings are subject to change 5912: ** without notice. These values are for testing purposes only. 5913: ** Applications should not use any of these parameters or the 5914: ** [sqlite3_test_control()] interface. 5915: */ 5916: #define SQLITE_TESTCTRL_FIRST 5 5917: #define SQLITE_TESTCTRL_PRNG_SAVE 5 5918: #define SQLITE_TESTCTRL_PRNG_RESTORE 6 5919: #define SQLITE_TESTCTRL_PRNG_RESET 7 5920: #define SQLITE_TESTCTRL_BITVEC_TEST 8 5921: #define SQLITE_TESTCTRL_FAULT_INSTALL 9 5922: #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 5923: #define SQLITE_TESTCTRL_PENDING_BYTE 11 5924: #define SQLITE_TESTCTRL_ASSERT 12 5925: #define SQLITE_TESTCTRL_ALWAYS 13 5926: #define SQLITE_TESTCTRL_RESERVE 14 5927: #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 5928: #define SQLITE_TESTCTRL_ISKEYWORD 16 5929: #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 5930: #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 5931: #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 5932: #define SQLITE_TESTCTRL_LAST 19 5933: 5934: /* 5935: ** CAPI3REF: SQLite Runtime Status 5936: ** 5937: ** ^This interface is used to retrieve runtime status information 5938: ** about the performance of SQLite, and optionally to reset various 5939: ** highwater marks. ^The first argument is an integer code for 5940: ** the specific parameter to measure. ^(Recognized integer codes 5941: ** are of the form [status parameters | SQLITE_STATUS_...].)^ 5942: ** ^The current value of the parameter is returned into *pCurrent. 5943: ** ^The highest recorded value is returned in *pHighwater. ^If the 5944: ** resetFlag is true, then the highest record value is reset after 5945: ** *pHighwater is written. ^(Some parameters do not record the highest 5946: ** value. For those parameters 5947: ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 5948: ** ^(Other parameters record only the highwater mark and not the current 5949: ** value. For these latter parameters nothing is written into *pCurrent.)^ 5950: ** 5951: ** ^The sqlite3_status() routine returns SQLITE_OK on success and a 5952: ** non-zero [error code] on failure. 5953: ** 5954: ** This routine is threadsafe but is not atomic. This routine can be 5955: ** called while other threads are running the same or different SQLite 5956: ** interfaces. However the values returned in *pCurrent and 5957: ** *pHighwater reflect the status of SQLite at different points in time 5958: ** and it is possible that another thread might change the parameter 5959: ** in between the times when *pCurrent and *pHighwater are written. 5960: ** 5961: ** See also: [sqlite3_db_status()] 5962: */ 5963: SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 5964: 5965: 5966: /* 5967: ** CAPI3REF: Status Parameters 5968: ** KEYWORDS: {status parameters} 5969: ** 5970: ** These integer constants designate various run-time status parameters 5971: ** that can be returned by [sqlite3_status()]. 5972: ** 5973: ** <dl> 5974: ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 5975: ** <dd>This parameter is the current amount of memory checked out 5976: ** using [sqlite3_malloc()], either directly or indirectly. The 5977: ** figure includes calls made to [sqlite3_malloc()] by the application 5978: ** and internal memory usage by the SQLite library. Scratch memory 5979: ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 5980: ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 5981: ** this parameter. The amount returned is the sum of the allocation 5982: ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 5983: ** 5984: ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 5985: ** <dd>This parameter records the largest memory allocation request 5986: ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 5987: ** internal equivalents). Only the value returned in the 5988: ** *pHighwater parameter to [sqlite3_status()] is of interest. 5989: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 5990: ** 5991: ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 5992: ** <dd>This parameter records the number of separate memory allocations 5993: ** currently checked out.</dd>)^ 5994: ** 5995: ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 5996: ** <dd>This parameter returns the number of pages used out of the 5997: ** [pagecache memory allocator] that was configured using 5998: ** [SQLITE_CONFIG_PAGECACHE]. The 5999: ** value returned is in pages, not in bytes.</dd>)^ 6000: ** 6001: ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6002: ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6003: ** <dd>This parameter returns the number of bytes of page cache 6004: ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6005: ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6006: ** returned value includes allocations that overflowed because they 6007: ** where too large (they were larger than the "sz" parameter to 6008: ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6009: ** no space was left in the page cache.</dd>)^ 6010: ** 6011: ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6012: ** <dd>This parameter records the largest memory allocation request 6013: ** handed to [pagecache memory allocator]. Only the value returned in the 6014: ** *pHighwater parameter to [sqlite3_status()] is of interest. 6015: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6016: ** 6017: ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6018: ** <dd>This parameter returns the number of allocations used out of the 6019: ** [scratch memory allocator] configured using 6020: ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6021: ** in bytes. Since a single thread may only have one scratch allocation 6022: ** outstanding at time, this parameter also reports the number of threads 6023: ** using scratch memory at the same time.</dd>)^ 6024: ** 6025: ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6026: ** <dd>This parameter returns the number of bytes of scratch memory 6027: ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6028: ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6029: ** returned include overflows because the requested allocation was too 6030: ** larger (that is, because the requested allocation was larger than the 6031: ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6032: ** slots were available. 6033: ** </dd>)^ 6034: ** 6035: ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6036: ** <dd>This parameter records the largest memory allocation request 6037: ** handed to [scratch memory allocator]. Only the value returned in the 6038: ** *pHighwater parameter to [sqlite3_status()] is of interest. 6039: ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6040: ** 6041: ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6042: ** <dd>This parameter records the deepest parser stack. It is only 6043: ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6044: ** </dl> 6045: ** 6046: ** New status parameters may be added from time to time. 6047: */ 6048: #define SQLITE_STATUS_MEMORY_USED 0 6049: #define SQLITE_STATUS_PAGECACHE_USED 1 6050: #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6051: #define SQLITE_STATUS_SCRATCH_USED 3 6052: #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6053: #define SQLITE_STATUS_MALLOC_SIZE 5 6054: #define SQLITE_STATUS_PARSER_STACK 6 6055: #define SQLITE_STATUS_PAGECACHE_SIZE 7 6056: #define SQLITE_STATUS_SCRATCH_SIZE 8 6057: #define SQLITE_STATUS_MALLOC_COUNT 9 6058: 6059: /* 6060: ** CAPI3REF: Database Connection Status 6061: ** 6062: ** ^This interface is used to retrieve runtime status information 6063: ** about a single [database connection]. ^The first argument is the 6064: ** database connection object to be interrogated. ^The second argument 6065: ** is an integer constant, taken from the set of 6066: ** [SQLITE_DBSTATUS options], that 6067: ** determines the parameter to interrogate. The set of 6068: ** [SQLITE_DBSTATUS options] is likely 6069: ** to grow in future releases of SQLite. 6070: ** 6071: ** ^The current value of the requested parameter is written into *pCur 6072: ** and the highest instantaneous value is written into *pHiwtr. ^If 6073: ** the resetFlg is true, then the highest instantaneous value is 6074: ** reset back down to the current value. 6075: ** 6076: ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6077: ** non-zero [error code] on failure. 6078: ** 6079: ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6080: */ 6081: SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6082: 6083: /* 6084: ** CAPI3REF: Status Parameters for database connections 6085: ** KEYWORDS: {SQLITE_DBSTATUS options} 6086: ** 6087: ** These constants are the available integer "verbs" that can be passed as 6088: ** the second argument to the [sqlite3_db_status()] interface. 6089: ** 6090: ** New verbs may be added in future releases of SQLite. Existing verbs 6091: ** might be discontinued. Applications should check the return code from 6092: ** [sqlite3_db_status()] to make sure that the call worked. 6093: ** The [sqlite3_db_status()] interface will return a non-zero error code 6094: ** if a discontinued or unsupported verb is invoked. 6095: ** 6096: ** <dl> 6097: ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6098: ** <dd>This parameter returns the number of lookaside memory slots currently 6099: ** checked out.</dd>)^ 6100: ** 6101: ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6102: ** <dd>This parameter returns the number malloc attempts that were 6103: ** satisfied using lookaside memory. Only the high-water value is meaningful; 6104: ** the current value is always zero.)^ 6105: ** 6106: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6107: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6108: ** <dd>This parameter returns the number malloc attempts that might have 6109: ** been satisfied using lookaside memory but failed due to the amount of 6110: ** memory requested being larger than the lookaside slot size. 6111: ** Only the high-water value is meaningful; 6112: ** the current value is always zero.)^ 6113: ** 6114: ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6115: ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6116: ** <dd>This parameter returns the number malloc attempts that might have 6117: ** been satisfied using lookaside memory but failed due to all lookaside 6118: ** memory already being in use. 6119: ** Only the high-water value is meaningful; 6120: ** the current value is always zero.)^ 6121: ** 6122: ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6123: ** <dd>This parameter returns the approximate number of of bytes of heap 6124: ** memory used by all pager caches associated with the database connection.)^ 6125: ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6126: ** 6127: ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6128: ** <dd>This parameter returns the approximate number of of bytes of heap 6129: ** memory used to store the schema for all databases associated 6130: ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6131: ** ^The full amount of memory used by the schemas is reported, even if the 6132: ** schema memory is shared with other database connections due to 6133: ** [shared cache mode] being enabled. 6134: ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6135: ** 6136: ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6137: ** <dd>This parameter returns the approximate number of of bytes of heap 6138: ** and lookaside memory used by all prepared statements associated with 6139: ** the database connection.)^ 6140: ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6141: ** </dd> 6142: ** 6143: ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6144: ** <dd>This parameter returns the number of pager cache hits that have 6145: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6146: ** is always 0. 6147: ** </dd> 6148: ** 6149: ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6150: ** <dd>This parameter returns the number of pager cache misses that have 6151: ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6152: ** is always 0. 6153: ** </dd> 1.3 ! misho 6154: ** ! 6155: ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> ! 6156: ** <dd>This parameter returns the number of dirty cache entries that have ! 6157: ** been written to disk. Specifically, the number of pages written to the ! 6158: ** wal file in wal mode databases, or the number of pages written to the ! 6159: ** database file in rollback mode databases. Any pages written as part of ! 6160: ** transaction rollback or database recovery operations are not included. ! 6161: ** If an IO or other error occurs while writing a page to disk, the effect ! 6162: ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The ! 6163: ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. ! 6164: ** </dd> 1.2 misho 6165: ** </dl> 6166: */ 6167: #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6168: #define SQLITE_DBSTATUS_CACHE_USED 1 6169: #define SQLITE_DBSTATUS_SCHEMA_USED 2 6170: #define SQLITE_DBSTATUS_STMT_USED 3 6171: #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6172: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6173: #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6174: #define SQLITE_DBSTATUS_CACHE_HIT 7 6175: #define SQLITE_DBSTATUS_CACHE_MISS 8 1.3 ! misho 6176: #define SQLITE_DBSTATUS_CACHE_WRITE 9 ! 6177: #define SQLITE_DBSTATUS_MAX 9 /* Largest defined DBSTATUS */ 1.2 misho 6178: 6179: 6180: /* 6181: ** CAPI3REF: Prepared Statement Status 6182: ** 6183: ** ^(Each prepared statement maintains various 6184: ** [SQLITE_STMTSTATUS counters] that measure the number 6185: ** of times it has performed specific operations.)^ These counters can 6186: ** be used to monitor the performance characteristics of the prepared 6187: ** statements. For example, if the number of table steps greatly exceeds 6188: ** the number of table searches or result rows, that would tend to indicate 6189: ** that the prepared statement is using a full table scan rather than 6190: ** an index. 6191: ** 6192: ** ^(This interface is used to retrieve and reset counter values from 6193: ** a [prepared statement]. The first argument is the prepared statement 6194: ** object to be interrogated. The second argument 6195: ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6196: ** to be interrogated.)^ 6197: ** ^The current value of the requested counter is returned. 6198: ** ^If the resetFlg is true, then the counter is reset to zero after this 6199: ** interface call returns. 6200: ** 6201: ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6202: */ 6203: SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6204: 6205: /* 6206: ** CAPI3REF: Status Parameters for prepared statements 6207: ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6208: ** 6209: ** These preprocessor macros define integer codes that name counter 6210: ** values associated with the [sqlite3_stmt_status()] interface. 6211: ** The meanings of the various counters are as follows: 6212: ** 6213: ** <dl> 6214: ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6215: ** <dd>^This is the number of times that SQLite has stepped forward in 6216: ** a table as part of a full table scan. Large numbers for this counter 6217: ** may indicate opportunities for performance improvement through 6218: ** careful use of indices.</dd> 6219: ** 6220: ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6221: ** <dd>^This is the number of sort operations that have occurred. 6222: ** A non-zero value in this counter may indicate an opportunity to 6223: ** improvement performance through careful use of indices.</dd> 6224: ** 6225: ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6226: ** <dd>^This is the number of rows inserted into transient indices that 6227: ** were created automatically in order to help joins run faster. 6228: ** A non-zero value in this counter may indicate an opportunity to 6229: ** improvement performance by adding permanent indices that do not 6230: ** need to be reinitialized each time the statement is run.</dd> 6231: ** </dl> 6232: */ 6233: #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6234: #define SQLITE_STMTSTATUS_SORT 2 6235: #define SQLITE_STMTSTATUS_AUTOINDEX 3 6236: 6237: /* 6238: ** CAPI3REF: Custom Page Cache Object 6239: ** 6240: ** The sqlite3_pcache type is opaque. It is implemented by 6241: ** the pluggable module. The SQLite core has no knowledge of 6242: ** its size or internal structure and never deals with the 6243: ** sqlite3_pcache object except by holding and passing pointers 6244: ** to the object. 6245: ** 6246: ** See [sqlite3_pcache_methods2] for additional information. 6247: */ 6248: typedef struct sqlite3_pcache sqlite3_pcache; 6249: 6250: /* 6251: ** CAPI3REF: Custom Page Cache Object 6252: ** 6253: ** The sqlite3_pcache_page object represents a single page in the 6254: ** page cache. The page cache will allocate instances of this 6255: ** object. Various methods of the page cache use pointers to instances 6256: ** of this object as parameters or as their return value. 6257: ** 6258: ** See [sqlite3_pcache_methods2] for additional information. 6259: */ 6260: typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6261: struct sqlite3_pcache_page { 6262: void *pBuf; /* The content of the page */ 6263: void *pExtra; /* Extra information associated with the page */ 6264: }; 6265: 6266: /* 6267: ** CAPI3REF: Application Defined Page Cache. 6268: ** KEYWORDS: {page cache} 6269: ** 6270: ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6271: ** register an alternative page cache implementation by passing in an 6272: ** instance of the sqlite3_pcache_methods2 structure.)^ 6273: ** In many applications, most of the heap memory allocated by 6274: ** SQLite is used for the page cache. 6275: ** By implementing a 6276: ** custom page cache using this API, an application can better control 6277: ** the amount of memory consumed by SQLite, the way in which 6278: ** that memory is allocated and released, and the policies used to 6279: ** determine exactly which parts of a database file are cached and for 6280: ** how long. 6281: ** 6282: ** The alternative page cache mechanism is an 6283: ** extreme measure that is only needed by the most demanding applications. 6284: ** The built-in page cache is recommended for most uses. 6285: ** 6286: ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6287: ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6288: ** the application may discard the parameter after the call to 6289: ** [sqlite3_config()] returns.)^ 6290: ** 6291: ** [[the xInit() page cache method]] 6292: ** ^(The xInit() method is called once for each effective 6293: ** call to [sqlite3_initialize()])^ 6294: ** (usually only once during the lifetime of the process). ^(The xInit() 6295: ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6296: ** The intent of the xInit() method is to set up global data structures 6297: ** required by the custom page cache implementation. 6298: ** ^(If the xInit() method is NULL, then the 6299: ** built-in default page cache is used instead of the application defined 6300: ** page cache.)^ 6301: ** 6302: ** [[the xShutdown() page cache method]] 6303: ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6304: ** It can be used to clean up 6305: ** any outstanding resources before process shutdown, if required. 6306: ** ^The xShutdown() method may be NULL. 6307: ** 6308: ** ^SQLite automatically serializes calls to the xInit method, 6309: ** so the xInit method need not be threadsafe. ^The 6310: ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6311: ** not need to be threadsafe either. All other methods must be threadsafe 6312: ** in multithreaded applications. 6313: ** 6314: ** ^SQLite will never invoke xInit() more than once without an intervening 6315: ** call to xShutdown(). 6316: ** 6317: ** [[the xCreate() page cache methods]] 6318: ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6319: ** SQLite will typically create one cache instance for each open database file, 6320: ** though this is not guaranteed. ^The 6321: ** first parameter, szPage, is the size in bytes of the pages that must 6322: ** be allocated by the cache. ^szPage will always a power of two. ^The 6323: ** second parameter szExtra is a number of bytes of extra storage 6324: ** associated with each page cache entry. ^The szExtra parameter will 6325: ** a number less than 250. SQLite will use the 6326: ** extra szExtra bytes on each page to store metadata about the underlying 6327: ** database page on disk. The value passed into szExtra depends 6328: ** on the SQLite version, the target platform, and how SQLite was compiled. 6329: ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6330: ** created will be used to cache database pages of a file stored on disk, or 6331: ** false if it is used for an in-memory database. The cache implementation 6332: ** does not have to do anything special based with the value of bPurgeable; 6333: ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6334: ** never invoke xUnpin() except to deliberately delete a page. 6335: ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6336: ** false will always have the "discard" flag set to true. 6337: ** ^Hence, a cache created with bPurgeable false will 6338: ** never contain any unpinned pages. 6339: ** 6340: ** [[the xCachesize() page cache method]] 6341: ** ^(The xCachesize() method may be called at any time by SQLite to set the 6342: ** suggested maximum cache-size (number of pages stored by) the cache 6343: ** instance passed as the first argument. This is the value configured using 6344: ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6345: ** parameter, the implementation is not required to do anything with this 6346: ** value; it is advisory only. 6347: ** 6348: ** [[the xPagecount() page cache methods]] 6349: ** The xPagecount() method must return the number of pages currently 6350: ** stored in the cache, both pinned and unpinned. 6351: ** 6352: ** [[the xFetch() page cache methods]] 6353: ** The xFetch() method locates a page in the cache and returns a pointer to 6354: ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6355: ** The pBuf element of the returned sqlite3_pcache_page object will be a 6356: ** pointer to a buffer of szPage bytes used to store the content of a 6357: ** single database page. The pExtra element of sqlite3_pcache_page will be 6358: ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6359: ** for each entry in the page cache. 6360: ** 6361: ** The page to be fetched is determined by the key. ^The minimum key value 6362: ** is 1. After it has been retrieved using xFetch, the page is considered 6363: ** to be "pinned". 6364: ** 6365: ** If the requested page is already in the page cache, then the page cache 6366: ** implementation must return a pointer to the page buffer with its content 6367: ** intact. If the requested page is not already in the cache, then the 6368: ** cache implementation should use the value of the createFlag 6369: ** parameter to help it determined what action to take: 6370: ** 6371: ** <table border=1 width=85% align=center> 6372: ** <tr><th> createFlag <th> Behaviour when page is not already in cache 6373: ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6374: ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6375: ** Otherwise return NULL. 6376: ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6377: ** NULL if allocating a new page is effectively impossible. 6378: ** </table> 6379: ** 6380: ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6381: ** will only use a createFlag of 2 after a prior call with a createFlag of 1 6382: ** failed.)^ In between the to xFetch() calls, SQLite may 6383: ** attempt to unpin one or more cache pages by spilling the content of 6384: ** pinned pages to disk and synching the operating system disk cache. 6385: ** 6386: ** [[the xUnpin() page cache method]] 6387: ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6388: ** as its second argument. If the third parameter, discard, is non-zero, 6389: ** then the page must be evicted from the cache. 6390: ** ^If the discard parameter is 6391: ** zero, then the page may be discarded or retained at the discretion of 6392: ** page cache implementation. ^The page cache implementation 6393: ** may choose to evict unpinned pages at any time. 6394: ** 6395: ** The cache must not perform any reference counting. A single 6396: ** call to xUnpin() unpins the page regardless of the number of prior calls 6397: ** to xFetch(). 6398: ** 6399: ** [[the xRekey() page cache methods]] 6400: ** The xRekey() method is used to change the key value associated with the 6401: ** page passed as the second argument. If the cache 6402: ** previously contains an entry associated with newKey, it must be 6403: ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6404: ** to be pinned. 6405: ** 6406: ** When SQLite calls the xTruncate() method, the cache must discard all 6407: ** existing cache entries with page numbers (keys) greater than or equal 6408: ** to the value of the iLimit parameter passed to xTruncate(). If any 6409: ** of these pages are pinned, they are implicitly unpinned, meaning that 6410: ** they can be safely discarded. 6411: ** 6412: ** [[the xDestroy() page cache method]] 6413: ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6414: ** All resources associated with the specified cache should be freed. ^After 6415: ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6416: ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6417: ** functions. 6418: ** 6419: ** [[the xShrink() page cache method]] 6420: ** ^SQLite invokes the xShrink() method when it wants the page cache to 6421: ** free up as much of heap memory as possible. The page cache implementation 6422: ** is not obligated to free any memory, but well-behaved implementations should 6423: ** do their best. 6424: */ 6425: typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6426: struct sqlite3_pcache_methods2 { 6427: int iVersion; 6428: void *pArg; 6429: int (*xInit)(void*); 6430: void (*xShutdown)(void*); 6431: sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6432: void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6433: int (*xPagecount)(sqlite3_pcache*); 6434: sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6435: void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6436: void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6437: unsigned oldKey, unsigned newKey); 6438: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6439: void (*xDestroy)(sqlite3_pcache*); 6440: void (*xShrink)(sqlite3_pcache*); 6441: }; 6442: 6443: /* 6444: ** This is the obsolete pcache_methods object that has now been replaced 6445: ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6446: ** retained in the header file for backwards compatibility only. 6447: */ 6448: typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6449: struct sqlite3_pcache_methods { 6450: void *pArg; 6451: int (*xInit)(void*); 6452: void (*xShutdown)(void*); 6453: sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6454: void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6455: int (*xPagecount)(sqlite3_pcache*); 6456: void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6457: void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6458: void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6459: void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6460: void (*xDestroy)(sqlite3_pcache*); 6461: }; 6462: 6463: 6464: /* 6465: ** CAPI3REF: Online Backup Object 6466: ** 6467: ** The sqlite3_backup object records state information about an ongoing 6468: ** online backup operation. ^The sqlite3_backup object is created by 6469: ** a call to [sqlite3_backup_init()] and is destroyed by a call to 6470: ** [sqlite3_backup_finish()]. 6471: ** 6472: ** See Also: [Using the SQLite Online Backup API] 6473: */ 6474: typedef struct sqlite3_backup sqlite3_backup; 6475: 6476: /* 6477: ** CAPI3REF: Online Backup API. 6478: ** 6479: ** The backup API copies the content of one database into another. 6480: ** It is useful either for creating backups of databases or 6481: ** for copying in-memory databases to or from persistent files. 6482: ** 6483: ** See Also: [Using the SQLite Online Backup API] 6484: ** 6485: ** ^SQLite holds a write transaction open on the destination database file 6486: ** for the duration of the backup operation. 6487: ** ^The source database is read-locked only while it is being read; 6488: ** it is not locked continuously for the entire backup operation. 6489: ** ^Thus, the backup may be performed on a live source database without 6490: ** preventing other database connections from 6491: ** reading or writing to the source database while the backup is underway. 6492: ** 6493: ** ^(To perform a backup operation: 6494: ** <ol> 6495: ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6496: ** backup, 6497: ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6498: ** the data between the two databases, and finally 6499: ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6500: ** associated with the backup operation. 6501: ** </ol>)^ 6502: ** There should be exactly one call to sqlite3_backup_finish() for each 6503: ** successful call to sqlite3_backup_init(). 6504: ** 6505: ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6506: ** 6507: ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6508: ** [database connection] associated with the destination database 6509: ** and the database name, respectively. 6510: ** ^The database name is "main" for the main database, "temp" for the 6511: ** temporary database, or the name specified after the AS keyword in 6512: ** an [ATTACH] statement for an attached database. 6513: ** ^The S and M arguments passed to 6514: ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6515: ** and database name of the source database, respectively. 6516: ** ^The source and destination [database connections] (parameters S and D) 6517: ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6518: ** an error. 6519: ** 6520: ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6521: ** returned and an error code and error message are stored in the 6522: ** destination [database connection] D. 6523: ** ^The error code and message for the failed call to sqlite3_backup_init() 6524: ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6525: ** [sqlite3_errmsg16()] functions. 6526: ** ^A successful call to sqlite3_backup_init() returns a pointer to an 6527: ** [sqlite3_backup] object. 6528: ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6529: ** sqlite3_backup_finish() functions to perform the specified backup 6530: ** operation. 6531: ** 6532: ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6533: ** 6534: ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6535: ** the source and destination databases specified by [sqlite3_backup] object B. 6536: ** ^If N is negative, all remaining source pages are copied. 6537: ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6538: ** are still more pages to be copied, then the function returns [SQLITE_OK]. 6539: ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6540: ** from source to destination, then it returns [SQLITE_DONE]. 6541: ** ^If an error occurs while running sqlite3_backup_step(B,N), 6542: ** then an [error code] is returned. ^As well as [SQLITE_OK] and 6543: ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6544: ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6545: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6546: ** 6547: ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6548: ** <ol> 6549: ** <li> the destination database was opened read-only, or 6550: ** <li> the destination database is using write-ahead-log journaling 6551: ** and the destination and source page sizes differ, or 6552: ** <li> the destination database is an in-memory database and the 6553: ** destination and source page sizes differ. 6554: ** </ol>)^ 6555: ** 6556: ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6557: ** the [sqlite3_busy_handler | busy-handler function] 6558: ** is invoked (if one is specified). ^If the 6559: ** busy-handler returns non-zero before the lock is available, then 6560: ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6561: ** sqlite3_backup_step() can be retried later. ^If the source 6562: ** [database connection] 6563: ** is being used to write to the source database when sqlite3_backup_step() 6564: ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6565: ** case the call to sqlite3_backup_step() can be retried later on. ^(If 6566: ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6567: ** [SQLITE_READONLY] is returned, then 6568: ** there is no point in retrying the call to sqlite3_backup_step(). These 6569: ** errors are considered fatal.)^ The application must accept 6570: ** that the backup operation has failed and pass the backup operation handle 6571: ** to the sqlite3_backup_finish() to release associated resources. 6572: ** 6573: ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6574: ** on the destination file. ^The exclusive lock is not released until either 6575: ** sqlite3_backup_finish() is called or the backup operation is complete 6576: ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6577: ** sqlite3_backup_step() obtains a [shared lock] on the source database that 6578: ** lasts for the duration of the sqlite3_backup_step() call. 6579: ** ^Because the source database is not locked between calls to 6580: ** sqlite3_backup_step(), the source database may be modified mid-way 6581: ** through the backup process. ^If the source database is modified by an 6582: ** external process or via a database connection other than the one being 6583: ** used by the backup operation, then the backup will be automatically 6584: ** restarted by the next call to sqlite3_backup_step(). ^If the source 6585: ** database is modified by the using the same database connection as is used 6586: ** by the backup operation, then the backup database is automatically 6587: ** updated at the same time. 6588: ** 6589: ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6590: ** 6591: ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6592: ** application wishes to abandon the backup operation, the application 6593: ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6594: ** ^The sqlite3_backup_finish() interfaces releases all 6595: ** resources associated with the [sqlite3_backup] object. 6596: ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6597: ** active write-transaction on the destination database is rolled back. 6598: ** The [sqlite3_backup] object is invalid 6599: ** and may not be used following a call to sqlite3_backup_finish(). 6600: ** 6601: ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6602: ** sqlite3_backup_step() errors occurred, regardless or whether or not 6603: ** sqlite3_backup_step() completed. 6604: ** ^If an out-of-memory condition or IO error occurred during any prior 6605: ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6606: ** sqlite3_backup_finish() returns the corresponding [error code]. 6607: ** 6608: ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6609: ** is not a permanent error and does not affect the return value of 6610: ** sqlite3_backup_finish(). 6611: ** 6612: ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6613: ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6614: ** 6615: ** ^Each call to sqlite3_backup_step() sets two values inside 6616: ** the [sqlite3_backup] object: the number of pages still to be backed 6617: ** up and the total number of pages in the source database file. 6618: ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6619: ** retrieve these two values, respectively. 6620: ** 6621: ** ^The values returned by these functions are only updated by 6622: ** sqlite3_backup_step(). ^If the source database is modified during a backup 6623: ** operation, then the values are not updated to account for any extra 6624: ** pages that need to be updated or the size of the source database file 6625: ** changing. 6626: ** 6627: ** <b>Concurrent Usage of Database Handles</b> 6628: ** 6629: ** ^The source [database connection] may be used by the application for other 6630: ** purposes while a backup operation is underway or being initialized. 6631: ** ^If SQLite is compiled and configured to support threadsafe database 6632: ** connections, then the source database connection may be used concurrently 6633: ** from within other threads. 6634: ** 6635: ** However, the application must guarantee that the destination 6636: ** [database connection] is not passed to any other API (by any thread) after 6637: ** sqlite3_backup_init() is called and before the corresponding call to 6638: ** sqlite3_backup_finish(). SQLite does not currently check to see 6639: ** if the application incorrectly accesses the destination [database connection] 6640: ** and so no error code is reported, but the operations may malfunction 6641: ** nevertheless. Use of the destination database connection while a 6642: ** backup is in progress might also also cause a mutex deadlock. 6643: ** 6644: ** If running in [shared cache mode], the application must 6645: ** guarantee that the shared cache used by the destination database 6646: ** is not accessed while the backup is running. In practice this means 6647: ** that the application must guarantee that the disk file being 6648: ** backed up to is not accessed by any connection within the process, 6649: ** not just the specific connection that was passed to sqlite3_backup_init(). 6650: ** 6651: ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6652: ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6653: ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6654: ** APIs are not strictly speaking threadsafe. If they are invoked at the 6655: ** same time as another thread is invoking sqlite3_backup_step() it is 6656: ** possible that they return invalid values. 6657: */ 6658: SQLITE_API sqlite3_backup *sqlite3_backup_init( 6659: sqlite3 *pDest, /* Destination database handle */ 6660: const char *zDestName, /* Destination database name */ 6661: sqlite3 *pSource, /* Source database handle */ 6662: const char *zSourceName /* Source database name */ 6663: ); 6664: SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6665: SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6666: SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6667: SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6668: 6669: /* 6670: ** CAPI3REF: Unlock Notification 6671: ** 6672: ** ^When running in shared-cache mode, a database operation may fail with 6673: ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6674: ** individual tables within the shared-cache cannot be obtained. See 6675: ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6676: ** ^This API may be used to register a callback that SQLite will invoke 6677: ** when the connection currently holding the required lock relinquishes it. 6678: ** ^This API is only available if the library was compiled with the 6679: ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6680: ** 6681: ** See Also: [Using the SQLite Unlock Notification Feature]. 6682: ** 6683: ** ^Shared-cache locks are released when a database connection concludes 6684: ** its current transaction, either by committing it or rolling it back. 6685: ** 6686: ** ^When a connection (known as the blocked connection) fails to obtain a 6687: ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6688: ** identity of the database connection (the blocking connection) that 6689: ** has locked the required resource is stored internally. ^After an 6690: ** application receives an SQLITE_LOCKED error, it may call the 6691: ** sqlite3_unlock_notify() method with the blocked connection handle as 6692: ** the first argument to register for a callback that will be invoked 6693: ** when the blocking connections current transaction is concluded. ^The 6694: ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6695: ** call that concludes the blocking connections transaction. 6696: ** 6697: ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6698: ** there is a chance that the blocking connection will have already 6699: ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6700: ** If this happens, then the specified callback is invoked immediately, 6701: ** from within the call to sqlite3_unlock_notify().)^ 6702: ** 6703: ** ^If the blocked connection is attempting to obtain a write-lock on a 6704: ** shared-cache table, and more than one other connection currently holds 6705: ** a read-lock on the same table, then SQLite arbitrarily selects one of 6706: ** the other connections to use as the blocking connection. 6707: ** 6708: ** ^(There may be at most one unlock-notify callback registered by a 6709: ** blocked connection. If sqlite3_unlock_notify() is called when the 6710: ** blocked connection already has a registered unlock-notify callback, 6711: ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6712: ** called with a NULL pointer as its second argument, then any existing 6713: ** unlock-notify callback is canceled. ^The blocked connections 6714: ** unlock-notify callback may also be canceled by closing the blocked 6715: ** connection using [sqlite3_close()]. 6716: ** 6717: ** The unlock-notify callback is not reentrant. If an application invokes 6718: ** any sqlite3_xxx API functions from within an unlock-notify callback, a 6719: ** crash or deadlock may be the result. 6720: ** 6721: ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6722: ** returns SQLITE_OK. 6723: ** 6724: ** <b>Callback Invocation Details</b> 6725: ** 6726: ** When an unlock-notify callback is registered, the application provides a 6727: ** single void* pointer that is passed to the callback when it is invoked. 6728: ** However, the signature of the callback function allows SQLite to pass 6729: ** it an array of void* context pointers. The first argument passed to 6730: ** an unlock-notify callback is a pointer to an array of void* pointers, 6731: ** and the second is the number of entries in the array. 6732: ** 6733: ** When a blocking connections transaction is concluded, there may be 6734: ** more than one blocked connection that has registered for an unlock-notify 6735: ** callback. ^If two or more such blocked connections have specified the 6736: ** same callback function, then instead of invoking the callback function 6737: ** multiple times, it is invoked once with the set of void* context pointers 6738: ** specified by the blocked connections bundled together into an array. 6739: ** This gives the application an opportunity to prioritize any actions 6740: ** related to the set of unblocked database connections. 6741: ** 6742: ** <b>Deadlock Detection</b> 6743: ** 6744: ** Assuming that after registering for an unlock-notify callback a 6745: ** database waits for the callback to be issued before taking any further 6746: ** action (a reasonable assumption), then using this API may cause the 6747: ** application to deadlock. For example, if connection X is waiting for 6748: ** connection Y's transaction to be concluded, and similarly connection 6749: ** Y is waiting on connection X's transaction, then neither connection 6750: ** will proceed and the system may remain deadlocked indefinitely. 6751: ** 6752: ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6753: ** detection. ^If a given call to sqlite3_unlock_notify() would put the 6754: ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6755: ** unlock-notify callback is registered. The system is said to be in 6756: ** a deadlocked state if connection A has registered for an unlock-notify 6757: ** callback on the conclusion of connection B's transaction, and connection 6758: ** B has itself registered for an unlock-notify callback when connection 6759: ** A's transaction is concluded. ^Indirect deadlock is also detected, so 6760: ** the system is also considered to be deadlocked if connection B has 6761: ** registered for an unlock-notify callback on the conclusion of connection 6762: ** C's transaction, where connection C is waiting on connection A. ^Any 6763: ** number of levels of indirection are allowed. 6764: ** 6765: ** <b>The "DROP TABLE" Exception</b> 6766: ** 6767: ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6768: ** always appropriate to call sqlite3_unlock_notify(). There is however, 6769: ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6770: ** SQLite checks if there are any currently executing SELECT statements 6771: ** that belong to the same connection. If there are, SQLITE_LOCKED is 6772: ** returned. In this case there is no "blocking connection", so invoking 6773: ** sqlite3_unlock_notify() results in the unlock-notify callback being 6774: ** invoked immediately. If the application then re-attempts the "DROP TABLE" 6775: ** or "DROP INDEX" query, an infinite loop might be the result. 6776: ** 6777: ** One way around this problem is to check the extended error code returned 6778: ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6779: ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6780: ** the special "DROP TABLE/INDEX" case, the extended error code is just 6781: ** SQLITE_LOCKED.)^ 6782: */ 6783: SQLITE_API int sqlite3_unlock_notify( 6784: sqlite3 *pBlocked, /* Waiting connection */ 6785: void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6786: void *pNotifyArg /* Argument to pass to xNotify */ 6787: ); 6788: 6789: 6790: /* 6791: ** CAPI3REF: String Comparison 6792: ** 1.3 ! misho 6793: ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications ! 6794: ** and extensions to compare the contents of two buffers containing UTF-8 ! 6795: ** strings in a case-independent fashion, using the same definition of "case ! 6796: ** independence" that SQLite uses internally when comparing identifiers. 1.2 misho 6797: */ 1.3 ! misho 6798: SQLITE_API int sqlite3_stricmp(const char *, const char *); 1.2 misho 6799: SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 6800: 6801: /* 6802: ** CAPI3REF: Error Logging Interface 6803: ** 6804: ** ^The [sqlite3_log()] interface writes a message into the error log 6805: ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 6806: ** ^If logging is enabled, the zFormat string and subsequent arguments are 6807: ** used with [sqlite3_snprintf()] to generate the final output string. 6808: ** 6809: ** The sqlite3_log() interface is intended for use by extensions such as 6810: ** virtual tables, collating functions, and SQL functions. While there is 6811: ** nothing to prevent an application from calling sqlite3_log(), doing so 6812: ** is considered bad form. 6813: ** 6814: ** The zFormat string must not be NULL. 6815: ** 6816: ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 6817: ** will not use dynamically allocated memory. The log message is stored in 6818: ** a fixed-length buffer on the stack. If the log message is longer than 6819: ** a few hundred characters, it will be truncated to the length of the 6820: ** buffer. 6821: */ 6822: SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 6823: 6824: /* 6825: ** CAPI3REF: Write-Ahead Log Commit Hook 6826: ** 6827: ** ^The [sqlite3_wal_hook()] function is used to register a callback that 6828: ** will be invoked each time a database connection commits data to a 6829: ** [write-ahead log] (i.e. whenever a transaction is committed in 6830: ** [journal_mode | journal_mode=WAL mode]). 6831: ** 6832: ** ^The callback is invoked by SQLite after the commit has taken place and 6833: ** the associated write-lock on the database released, so the implementation 6834: ** may read, write or [checkpoint] the database as required. 6835: ** 6836: ** ^The first parameter passed to the callback function when it is invoked 6837: ** is a copy of the third parameter passed to sqlite3_wal_hook() when 6838: ** registering the callback. ^The second is a copy of the database handle. 6839: ** ^The third parameter is the name of the database that was written to - 6840: ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 6841: ** is the number of pages currently in the write-ahead log file, 6842: ** including those that were just committed. 6843: ** 6844: ** The callback function should normally return [SQLITE_OK]. ^If an error 6845: ** code is returned, that error will propagate back up through the 6846: ** SQLite code base to cause the statement that provoked the callback 6847: ** to report an error, though the commit will have still occurred. If the 6848: ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 6849: ** that does not correspond to any valid SQLite error code, the results 6850: ** are undefined. 6851: ** 6852: ** A single database handle may have at most a single write-ahead log callback 6853: ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 6854: ** previously registered write-ahead log callback. ^Note that the 6855: ** [sqlite3_wal_autocheckpoint()] interface and the 6856: ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 6857: ** those overwrite any prior [sqlite3_wal_hook()] settings. 6858: */ 6859: SQLITE_API void *sqlite3_wal_hook( 6860: sqlite3*, 6861: int(*)(void *,sqlite3*,const char*,int), 6862: void* 6863: ); 6864: 6865: /* 6866: ** CAPI3REF: Configure an auto-checkpoint 6867: ** 6868: ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 6869: ** [sqlite3_wal_hook()] that causes any database on [database connection] D 6870: ** to automatically [checkpoint] 6871: ** after committing a transaction if there are N or 6872: ** more frames in the [write-ahead log] file. ^Passing zero or 6873: ** a negative value as the nFrame parameter disables automatic 6874: ** checkpoints entirely. 6875: ** 6876: ** ^The callback registered by this function replaces any existing callback 6877: ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 6878: ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 6879: ** configured by this function. 6880: ** 6881: ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 6882: ** from SQL. 6883: ** 6884: ** ^Every new [database connection] defaults to having the auto-checkpoint 6885: ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 6886: ** pages. The use of this interface 6887: ** is only necessary if the default setting is found to be suboptimal 6888: ** for a particular application. 6889: */ 6890: SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 6891: 6892: /* 6893: ** CAPI3REF: Checkpoint a database 6894: ** 6895: ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 6896: ** on [database connection] D to be [checkpointed]. ^If X is NULL or an 6897: ** empty string, then a checkpoint is run on all databases of 6898: ** connection D. ^If the database connection D is not in 6899: ** [WAL | write-ahead log mode] then this interface is a harmless no-op. 6900: ** 6901: ** ^The [wal_checkpoint pragma] can be used to invoke this interface 6902: ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 6903: ** [wal_autocheckpoint pragma] can be used to cause this interface to be 6904: ** run whenever the WAL reaches a certain size threshold. 6905: ** 6906: ** See also: [sqlite3_wal_checkpoint_v2()] 6907: */ 6908: SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 6909: 6910: /* 6911: ** CAPI3REF: Checkpoint a database 6912: ** 6913: ** Run a checkpoint operation on WAL database zDb attached to database 6914: ** handle db. The specific operation is determined by the value of the 6915: ** eMode parameter: 6916: ** 6917: ** <dl> 6918: ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 6919: ** Checkpoint as many frames as possible without waiting for any database 6920: ** readers or writers to finish. Sync the db file if all frames in the log 6921: ** are checkpointed. This mode is the same as calling 6922: ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 6923: ** 6924: ** <dt>SQLITE_CHECKPOINT_FULL<dd> 6925: ** This mode blocks (calls the busy-handler callback) until there is no 6926: ** database writer and all readers are reading from the most recent database 6927: ** snapshot. It then checkpoints all frames in the log file and syncs the 6928: ** database file. This call blocks database writers while it is running, 6929: ** but not database readers. 6930: ** 6931: ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 6932: ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 6933: ** checkpointing the log file it blocks (calls the busy-handler callback) 6934: ** until all readers are reading from the database file only. This ensures 6935: ** that the next client to write to the database file restarts the log file 6936: ** from the beginning. This call blocks database writers while it is running, 6937: ** but not database readers. 6938: ** </dl> 6939: ** 6940: ** If pnLog is not NULL, then *pnLog is set to the total number of frames in 6941: ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 6942: ** the total number of checkpointed frames (including any that were already 6943: ** checkpointed when this function is called). *pnLog and *pnCkpt may be 6944: ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 6945: ** If no values are available because of an error, they are both set to -1 6946: ** before returning to communicate this to the caller. 6947: ** 6948: ** All calls obtain an exclusive "checkpoint" lock on the database file. If 6949: ** any other process is running a checkpoint operation at the same time, the 6950: ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 6951: ** busy-handler configured, it will not be invoked in this case. 6952: ** 6953: ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 6954: ** "writer" lock on the database file. If the writer lock cannot be obtained 6955: ** immediately, and a busy-handler is configured, it is invoked and the writer 6956: ** lock retried until either the busy-handler returns 0 or the lock is 6957: ** successfully obtained. The busy-handler is also invoked while waiting for 6958: ** database readers as described above. If the busy-handler returns 0 before 6959: ** the writer lock is obtained or while waiting for database readers, the 6960: ** checkpoint operation proceeds from that point in the same way as 6961: ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 6962: ** without blocking any further. SQLITE_BUSY is returned in this case. 6963: ** 6964: ** If parameter zDb is NULL or points to a zero length string, then the 6965: ** specified operation is attempted on all WAL databases. In this case the 6966: ** values written to output parameters *pnLog and *pnCkpt are undefined. If 6967: ** an SQLITE_BUSY error is encountered when processing one or more of the 6968: ** attached WAL databases, the operation is still attempted on any remaining 6969: ** attached databases and SQLITE_BUSY is returned to the caller. If any other 6970: ** error occurs while processing an attached database, processing is abandoned 6971: ** and the error code returned to the caller immediately. If no error 6972: ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 6973: ** databases, SQLITE_OK is returned. 6974: ** 6975: ** If database zDb is the name of an attached database that is not in WAL 6976: ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 6977: ** zDb is not NULL (or a zero length string) and is not the name of any 6978: ** attached database, SQLITE_ERROR is returned to the caller. 6979: */ 6980: SQLITE_API int sqlite3_wal_checkpoint_v2( 6981: sqlite3 *db, /* Database handle */ 6982: const char *zDb, /* Name of attached database (or NULL) */ 6983: int eMode, /* SQLITE_CHECKPOINT_* value */ 6984: int *pnLog, /* OUT: Size of WAL log in frames */ 6985: int *pnCkpt /* OUT: Total number of frames checkpointed */ 6986: ); 6987: 6988: /* 6989: ** CAPI3REF: Checkpoint operation parameters 6990: ** 6991: ** These constants can be used as the 3rd parameter to 6992: ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 6993: ** documentation for additional information about the meaning and use of 6994: ** each of these values. 6995: */ 6996: #define SQLITE_CHECKPOINT_PASSIVE 0 6997: #define SQLITE_CHECKPOINT_FULL 1 6998: #define SQLITE_CHECKPOINT_RESTART 2 6999: 7000: /* 7001: ** CAPI3REF: Virtual Table Interface Configuration 7002: ** 7003: ** This function may be called by either the [xConnect] or [xCreate] method 7004: ** of a [virtual table] implementation to configure 7005: ** various facets of the virtual table interface. 7006: ** 7007: ** If this interface is invoked outside the context of an xConnect or 7008: ** xCreate virtual table method then the behavior is undefined. 7009: ** 7010: ** At present, there is only one option that may be configured using 7011: ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7012: ** may be added in the future. 7013: */ 7014: SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7015: 7016: /* 7017: ** CAPI3REF: Virtual Table Configuration Options 7018: ** 7019: ** These macros define the various options to the 7020: ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7021: ** can use to customize and optimize their behavior. 7022: ** 7023: ** <dl> 7024: ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7025: ** <dd>Calls of the form 7026: ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7027: ** where X is an integer. If X is zero, then the [virtual table] whose 7028: ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7029: ** support constraints. In this configuration (which is the default) if 7030: ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7031: ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7032: ** specified as part of the users SQL statement, regardless of the actual 7033: ** ON CONFLICT mode specified. 7034: ** 7035: ** If X is non-zero, then the virtual table implementation guarantees 7036: ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7037: ** any modifications to internal or persistent data structures have been made. 7038: ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7039: ** is able to roll back a statement or database transaction, and abandon 7040: ** or continue processing the current SQL statement as appropriate. 7041: ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7042: ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7043: ** had been ABORT. 7044: ** 7045: ** Virtual table implementations that are required to handle OR REPLACE 7046: ** must do so within the [xUpdate] method. If a call to the 7047: ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7048: ** CONFLICT policy is REPLACE, the virtual table implementation should 7049: ** silently replace the appropriate rows within the xUpdate callback and 7050: ** return SQLITE_OK. Or, if this is not possible, it may return 7051: ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7052: ** constraint handling. 7053: ** </dl> 7054: */ 7055: #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7056: 7057: /* 7058: ** CAPI3REF: Determine The Virtual Table Conflict Policy 7059: ** 7060: ** This function may only be called from within a call to the [xUpdate] method 7061: ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7062: ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7063: ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7064: ** of the SQL statement that triggered the call to the [xUpdate] method of the 7065: ** [virtual table]. 7066: */ 7067: SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 7068: 7069: /* 7070: ** CAPI3REF: Conflict resolution modes 7071: ** 7072: ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7073: ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7074: ** is for the SQL statement being evaluated. 7075: ** 7076: ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7077: ** return value from the [sqlite3_set_authorizer()] callback and that 7078: ** [SQLITE_ABORT] is also a [result code]. 7079: */ 7080: #define SQLITE_ROLLBACK 1 7081: /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7082: #define SQLITE_FAIL 3 7083: /* #define SQLITE_ABORT 4 // Also an error code */ 7084: #define SQLITE_REPLACE 5 7085: 7086: 7087: 7088: /* 7089: ** Undo the hack that converts floating point types to integer for 7090: ** builds on processors without floating point support. 7091: */ 7092: #ifdef SQLITE_OMIT_FLOATING_POINT 7093: # undef double 7094: #endif 7095: 7096: #ifdef __cplusplus 7097: } /* End of the 'extern "C"' block */ 7098: #endif 7099: #endif 7100: 7101: /* 7102: ** 2010 August 30 7103: ** 7104: ** The author disclaims copyright to this source code. In place of 7105: ** a legal notice, here is a blessing: 7106: ** 7107: ** May you do good and not evil. 7108: ** May you find forgiveness for yourself and forgive others. 7109: ** May you share freely, never taking more than you give. 7110: ** 7111: ************************************************************************* 7112: */ 7113: 7114: #ifndef _SQLITE3RTREE_H_ 7115: #define _SQLITE3RTREE_H_ 7116: 7117: 7118: #ifdef __cplusplus 7119: extern "C" { 7120: #endif 7121: 7122: typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7123: 7124: /* 7125: ** Register a geometry callback named zGeom that can be used as part of an 7126: ** R-Tree geometry query as follows: 7127: ** 7128: ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7129: */ 7130: SQLITE_API int sqlite3_rtree_geometry_callback( 7131: sqlite3 *db, 7132: const char *zGeom, 1.3 ! misho 7133: #ifdef SQLITE_RTREE_INT_ONLY ! 7134: int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), ! 7135: #else ! 7136: int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), ! 7137: #endif 1.2 misho 7138: void *pContext 7139: ); 7140: 7141: 7142: /* 7143: ** A pointer to a structure of the following type is passed as the first 7144: ** argument to callbacks registered using rtree_geometry_callback(). 7145: */ 7146: struct sqlite3_rtree_geometry { 7147: void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7148: int nParam; /* Size of array aParam[] */ 7149: double *aParam; /* Parameters passed to SQL geom function */ 7150: void *pUser; /* Callback implementation user data */ 7151: void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7152: }; 7153: 7154: 7155: #ifdef __cplusplus 7156: } /* end of the 'extern "C"' block */ 7157: #endif 7158: 7159: #endif /* ifndef _SQLITE3RTREE_H_ */ 7160: