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 41extern "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/* 53** These no-op macros are used in front of interfaces to mark those 54** interfaces as either deprecated or experimental. New applications 55** should not use deprecated interfaces - they are support for backwards 56** compatibility only. Application writers should be aware that 57** experimental interfaces are subject to change in point releases. 58** 59** These macros used to resolve to various kinds of compiler magic that 60** would generate warning messages when they were used. But that 61** compiler magic ended up generating such a flurry of bug reports 62** that we have taken it all out and gone back to using simple 63** noop macros. 64*/ 65#define SQLITE_DEPRECATED 66#define SQLITE_EXPERIMENTAL 67 68/* 69** Ensure these symbols were not defined by some previous header file. 70*/ 71#ifdef SQLITE_VERSION 72# undef SQLITE_VERSION 73#endif 74#ifdef SQLITE_VERSION_NUMBER 75# undef SQLITE_VERSION_NUMBER 76#endif 77 78/* 79** CAPI3REF: Compile-Time Library Version Numbers 80** 81** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 82** evaluates to a string literal that is the SQLite version in the 83** format "X.Y.Z" where X is the major version number (always 3 for 84** SQLite3) and Y is the minor version number and Z is the release number.)^ 85** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 86** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 87** numbers used in [SQLITE_VERSION].)^ 88** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 89** be larger than the release from which it is derived. Either Y will 90** be held constant and Z will be incremented or else Y will be incremented 91** and Z will be reset to zero. 92** 93** Since version 3.6.18, SQLite source code has been stored in the 94** <a href="http://www.fossil-scm.org/">Fossil configuration management 95** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 96** a string which identifies a particular check-in of SQLite 97** within its configuration management system. ^The SQLITE_SOURCE_ID 98** string contains the date and time of the check-in (UTC) and an SHA1 99** hash of the entire source tree. 100** 101** See also: [sqlite3_libversion()], 102** [sqlite3_libversion_number()], [sqlite3_sourceid()], 103** [sqlite_version()] and [sqlite_source_id()]. 104*/ 105#define SQLITE_VERSION "--VERS--" 106#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 107#define SQLITE_SOURCE_ID "--SOURCE-ID--" 108 109/* 110** CAPI3REF: Run-Time Library Version Numbers 111** KEYWORDS: sqlite3_version, sqlite3_sourceid 112** 113** These interfaces provide the same information as the [SQLITE_VERSION], 114** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 115** but are associated with the library instead of the header file. ^(Cautious 116** programmers might include assert() statements in their application to 117** verify that values returned by these interfaces match the macros in 118** the header, and thus insure that the application is 119** compiled with matching library and header files. 120** 121** <blockquote><pre> 122** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 123** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 124** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 125** </pre></blockquote>)^ 126** 127** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 128** macro. ^The sqlite3_libversion() function returns a pointer to the 129** to the sqlite3_version[] string constant. The sqlite3_libversion() 130** function is provided for use in DLLs since DLL users usually do not have 131** direct access to string constants within the DLL. ^The 132** sqlite3_libversion_number() function returns an integer equal to 133** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 134** a pointer to a string constant whose value is the same as the 135** [SQLITE_SOURCE_ID] C preprocessor macro. 136** 137** See also: [sqlite_version()] and [sqlite_source_id()]. 138*/ 139SQLITE_EXTERN const char sqlite3_version[]; 140const char *sqlite3_libversion(void); 141const char *sqlite3_sourceid(void); 142int sqlite3_libversion_number(void); 143 144/* 145** CAPI3REF: Run-Time Library Compilation Options Diagnostics 146** 147** ^The sqlite3_compileoption_used() function returns 0 or 1 148** indicating whether the specified option was defined at 149** compile time. ^The SQLITE_ prefix may be omitted from the 150** option name passed to sqlite3_compileoption_used(). 151** 152** ^The sqlite3_compileoption_get() function allows iterating 153** over the list of options that were defined at compile time by 154** returning the N-th compile time option string. ^If N is out of range, 155** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 156** prefix is omitted from any strings returned by 157** sqlite3_compileoption_get(). 158** 159** ^Support for the diagnostic functions sqlite3_compileoption_used() 160** and sqlite3_compileoption_get() may be omitted by specifying the 161** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 162** 163** See also: SQL functions [sqlite_compileoption_used()] and 164** [sqlite_compileoption_get()] and the [compile_options pragma]. 165*/ 166#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 167int sqlite3_compileoption_used(const char *zOptName); 168const char *sqlite3_compileoption_get(int N); 169#endif 170 171/* 172** CAPI3REF: Test To See If The Library Is Threadsafe 173** 174** ^The sqlite3_threadsafe() function returns zero if and only if 175** SQLite was compiled with mutexing code omitted due to the 176** [SQLITE_THREADSAFE] compile-time option being set to 0. 177** 178** SQLite can be compiled with or without mutexes. When 179** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 180** are enabled and SQLite is threadsafe. When the 181** [SQLITE_THREADSAFE] macro is 0, 182** the mutexes are omitted. Without the mutexes, it is not safe 183** to use SQLite concurrently from more than one thread. 184** 185** Enabling mutexes incurs a measurable performance penalty. 186** So if speed is of utmost importance, it makes sense to disable 187** the mutexes. But for maximum safety, mutexes should be enabled. 188** ^The default behavior is for mutexes to be enabled. 189** 190** This interface can be used by an application to make sure that the 191** version of SQLite that it is linking against was compiled with 192** the desired setting of the [SQLITE_THREADSAFE] macro. 193** 194** This interface only reports on the compile-time mutex setting 195** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 196** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 197** can be fully or partially disabled using a call to [sqlite3_config()] 198** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 199** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 200** sqlite3_threadsafe() function shows only the compile-time setting of 201** thread safety, not any run-time changes to that setting made by 202** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 203** is unchanged by calls to sqlite3_config().)^ 204** 205** See the [threading mode] documentation for additional information. 206*/ 207int sqlite3_threadsafe(void); 208 209/* 210** CAPI3REF: Database Connection Handle 211** KEYWORDS: {database connection} {database connections} 212** 213** Each open SQLite database is represented by a pointer to an instance of 214** the opaque structure named "sqlite3". It is useful to think of an sqlite3 215** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 216** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 217** and [sqlite3_close_v2()] are its destructors. There are many other 218** interfaces (such as 219** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 220** [sqlite3_busy_timeout()] to name but three) that are methods on an 221** sqlite3 object. 222*/ 223typedef struct sqlite3 sqlite3; 224 225/* 226** CAPI3REF: 64-Bit Integer Types 227** KEYWORDS: sqlite_int64 sqlite_uint64 228** 229** Because there is no cross-platform way to specify 64-bit integer types 230** SQLite includes typedefs for 64-bit signed and unsigned integers. 231** 232** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 233** The sqlite_int64 and sqlite_uint64 types are supported for backwards 234** compatibility only. 235** 236** ^The sqlite3_int64 and sqlite_int64 types can store integer values 237** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 238** sqlite3_uint64 and sqlite_uint64 types can store integer values 239** between 0 and +18446744073709551615 inclusive. 240*/ 241#ifdef SQLITE_INT64_TYPE 242 typedef SQLITE_INT64_TYPE sqlite_int64; 243 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 244#elif defined(_MSC_VER) || defined(__BORLANDC__) 245 typedef __int64 sqlite_int64; 246 typedef unsigned __int64 sqlite_uint64; 247#else 248 typedef long long int sqlite_int64; 249 typedef unsigned long long int sqlite_uint64; 250#endif 251typedef sqlite_int64 sqlite3_int64; 252typedef sqlite_uint64 sqlite3_uint64; 253 254/* 255** If compiling for a processor that lacks floating point support, 256** substitute integer for floating-point. 257*/ 258#ifdef SQLITE_OMIT_FLOATING_POINT 259# define double sqlite3_int64 260#endif 261 262/* 263** CAPI3REF: Closing A Database Connection 264** 265** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 266** for the [sqlite3] object. 267** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 268** the [sqlite3] object is successfully destroyed and all associated 269** resources are deallocated. 270** 271** ^If the database connection is associated with unfinalized prepared 272** statements or unfinished sqlite3_backup objects then sqlite3_close() 273** will leave the database connection open and return [SQLITE_BUSY]. 274** ^If sqlite3_close_v2() is called with unfinalized prepared statements 275** and/or unfinished sqlite3_backups, then the database connection becomes 276** an unusable "zombie" which will automatically be deallocated when the 277** last prepared statement is finalized or the last sqlite3_backup is 278** finished. The sqlite3_close_v2() interface is intended for use with 279** host languages that are garbage collected, and where the order in which 280** destructors are called is arbitrary. 281** 282** Applications should [sqlite3_finalize | finalize] all [prepared statements], 283** [sqlite3_blob_close | close] all [BLOB handles], and 284** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 285** with the [sqlite3] object prior to attempting to close the object. ^If 286** sqlite3_close_v2() is called on a [database connection] that still has 287** outstanding [prepared statements], [BLOB handles], and/or 288** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 289** of resources is deferred until all [prepared statements], [BLOB handles], 290** and [sqlite3_backup] objects are also destroyed. 291** 292** ^If an [sqlite3] object is destroyed while a transaction is open, 293** the transaction is automatically rolled back. 294** 295** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 296** must be either a NULL 297** pointer or an [sqlite3] object pointer obtained 298** from [sqlite3_open()], [sqlite3_open16()], or 299** [sqlite3_open_v2()], and not previously closed. 300** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 301** argument is a harmless no-op. 302*/ 303int sqlite3_close(sqlite3*); 304int sqlite3_close_v2(sqlite3*); 305 306/* 307** The type for a callback function. 308** This is legacy and deprecated. It is included for historical 309** compatibility and is not documented. 310*/ 311typedef int (*sqlite3_callback)(void*,int,char**, char**); 312 313/* 314** CAPI3REF: One-Step Query Execution Interface 315** 316** The sqlite3_exec() interface is a convenience wrapper around 317** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 318** that allows an application to run multiple statements of SQL 319** without having to use a lot of C code. 320** 321** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 322** semicolon-separate SQL statements passed into its 2nd argument, 323** in the context of the [database connection] passed in as its 1st 324** argument. ^If the callback function of the 3rd argument to 325** sqlite3_exec() is not NULL, then it is invoked for each result row 326** coming out of the evaluated SQL statements. ^The 4th argument to 327** sqlite3_exec() is relayed through to the 1st argument of each 328** callback invocation. ^If the callback pointer to sqlite3_exec() 329** is NULL, then no callback is ever invoked and result rows are 330** ignored. 331** 332** ^If an error occurs while evaluating the SQL statements passed into 333** sqlite3_exec(), then execution of the current statement stops and 334** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 335** is not NULL then any error message is written into memory obtained 336** from [sqlite3_malloc()] and passed back through the 5th parameter. 337** To avoid memory leaks, the application should invoke [sqlite3_free()] 338** on error message strings returned through the 5th parameter of 339** of sqlite3_exec() after the error message string is no longer needed. 340** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 341** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 342** NULL before returning. 343** 344** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 345** routine returns SQLITE_ABORT without invoking the callback again and 346** without running any subsequent SQL statements. 347** 348** ^The 2nd argument to the sqlite3_exec() callback function is the 349** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 350** callback is an array of pointers to strings obtained as if from 351** [sqlite3_column_text()], one for each column. ^If an element of a 352** result row is NULL then the corresponding string pointer for the 353** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 354** sqlite3_exec() callback is an array of pointers to strings where each 355** entry represents the name of corresponding result column as obtained 356** from [sqlite3_column_name()]. 357** 358** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 359** to an empty string, or a pointer that contains only whitespace and/or 360** SQL comments, then no SQL statements are evaluated and the database 361** is not changed. 362** 363** Restrictions: 364** 365** <ul> 366** <li> The application must insure that the 1st parameter to sqlite3_exec() 367** is a valid and open [database connection]. 368** <li> The application must not close the [database connection] specified by 369** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 370** <li> The application must not modify the SQL statement text passed into 371** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 372** </ul> 373*/ 374int sqlite3_exec( 375 sqlite3*, /* An open database */ 376 const char *sql, /* SQL to be evaluated */ 377 int (*callback)(void*,int,char**,char**), /* Callback function */ 378 void *, /* 1st argument to callback */ 379 char **errmsg /* Error msg written here */ 380); 381 382/* 383** CAPI3REF: Result Codes 384** KEYWORDS: {result code definitions} 385** 386** Many SQLite functions return an integer result code from the set shown 387** here in order to indicate success or failure. 388** 389** New error codes may be added in future versions of SQLite. 390** 391** See also: [extended result code definitions] 392*/ 393#define SQLITE_OK 0 /* Successful result */ 394/* beginning-of-error-codes */ 395#define SQLITE_ERROR 1 /* SQL error or missing database */ 396#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 397#define SQLITE_PERM 3 /* Access permission denied */ 398#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 399#define SQLITE_BUSY 5 /* The database file is locked */ 400#define SQLITE_LOCKED 6 /* A table in the database is locked */ 401#define SQLITE_NOMEM 7 /* A malloc() failed */ 402#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 403#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 404#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 405#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 406#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 407#define SQLITE_FULL 13 /* Insertion failed because database is full */ 408#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 409#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 410#define SQLITE_EMPTY 16 /* Database is empty */ 411#define SQLITE_SCHEMA 17 /* The database schema changed */ 412#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 413#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 414#define SQLITE_MISMATCH 20 /* Data type mismatch */ 415#define SQLITE_MISUSE 21 /* Library used incorrectly */ 416#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 417#define SQLITE_AUTH 23 /* Authorization denied */ 418#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 419#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 420#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 421#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 422#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 423#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 424#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 425/* end-of-error-codes */ 426 427/* 428** CAPI3REF: Extended Result Codes 429** KEYWORDS: {extended result code definitions} 430** 431** In its default configuration, SQLite API routines return one of 30 integer 432** [result codes]. However, experience has shown that many of 433** these result codes are too coarse-grained. They do not provide as 434** much information about problems as programmers might like. In an effort to 435** address this, newer versions of SQLite (version 3.3.8 and later) include 436** support for additional result codes that provide more detailed information 437** about errors. These [extended result codes] are enabled or disabled 438** on a per database connection basis using the 439** [sqlite3_extended_result_codes()] API. Or, the extended code for 440** the most recent error can be obtained using 441** [sqlite3_extended_errcode()]. 442*/ 443#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 444#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 445#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 446#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 447#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 448#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 449#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 450#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 451#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 452#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 453#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 454#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 455#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 456#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 457#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 458#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 459#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 460#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 461#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 462#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 463#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 464#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 465#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 466#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 467#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 468#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 469#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 470#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 471#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 472#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 473#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 474#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 475#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 476#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 477#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 478#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 479#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 480#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 481#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 482#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 483#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 484#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 485#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 486#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 487#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 488#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 489#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 490#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 491#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 492#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 493#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 494#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 495 496/* 497** CAPI3REF: Flags For File Open Operations 498** 499** These bit values are intended for use in the 500** 3rd parameter to the [sqlite3_open_v2()] interface and 501** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 502*/ 503#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 504#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 505#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 506#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 507#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 508#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 509#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 510#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 511#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 512#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 513#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 514#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 515#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 516#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 517#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 518#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 519#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 520#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 521#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 522#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 523 524/* Reserved: 0x00F00000 */ 525 526/* 527** CAPI3REF: Device Characteristics 528** 529** The xDeviceCharacteristics method of the [sqlite3_io_methods] 530** object returns an integer which is a vector of these 531** bit values expressing I/O characteristics of the mass storage 532** device that holds the file that the [sqlite3_io_methods] 533** refers to. 534** 535** The SQLITE_IOCAP_ATOMIC property means that all writes of 536** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 537** mean that writes of blocks that are nnn bytes in size and 538** are aligned to an address which is an integer multiple of 539** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 540** that when data is appended to a file, the data is appended 541** first then the size of the file is extended, never the other 542** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 543** information is written to disk in the same order as calls 544** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 545** after reboot following a crash or power loss, the only bytes in a 546** file that were written at the application level might have changed 547** and that adjacent bytes, even bytes within the same sector are 548** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 549** flag indicate that a file cannot be deleted when open. The 550** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 551** read-only media and cannot be changed even by processes with 552** elevated privileges. 553*/ 554#define SQLITE_IOCAP_ATOMIC 0x00000001 555#define SQLITE_IOCAP_ATOMIC512 0x00000002 556#define SQLITE_IOCAP_ATOMIC1K 0x00000004 557#define SQLITE_IOCAP_ATOMIC2K 0x00000008 558#define SQLITE_IOCAP_ATOMIC4K 0x00000010 559#define SQLITE_IOCAP_ATOMIC8K 0x00000020 560#define SQLITE_IOCAP_ATOMIC16K 0x00000040 561#define SQLITE_IOCAP_ATOMIC32K 0x00000080 562#define SQLITE_IOCAP_ATOMIC64K 0x00000100 563#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 564#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 565#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 566#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 567#define SQLITE_IOCAP_IMMUTABLE 0x00002000 568 569/* 570** CAPI3REF: File Locking Levels 571** 572** SQLite uses one of these integer values as the second 573** argument to calls it makes to the xLock() and xUnlock() methods 574** of an [sqlite3_io_methods] object. 575*/ 576#define SQLITE_LOCK_NONE 0 577#define SQLITE_LOCK_SHARED 1 578#define SQLITE_LOCK_RESERVED 2 579#define SQLITE_LOCK_PENDING 3 580#define SQLITE_LOCK_EXCLUSIVE 4 581 582/* 583** CAPI3REF: Synchronization Type Flags 584** 585** When SQLite invokes the xSync() method of an 586** [sqlite3_io_methods] object it uses a combination of 587** these integer values as the second argument. 588** 589** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 590** sync operation only needs to flush data to mass storage. Inode 591** information need not be flushed. If the lower four bits of the flag 592** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 593** If the lower four bits equal SQLITE_SYNC_FULL, that means 594** to use Mac OS X style fullsync instead of fsync(). 595** 596** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 597** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 598** settings. The [synchronous pragma] determines when calls to the 599** xSync VFS method occur and applies uniformly across all platforms. 600** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 601** energetic or rigorous or forceful the sync operations are and 602** only make a difference on Mac OSX for the default SQLite code. 603** (Third-party VFS implementations might also make the distinction 604** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 605** operating systems natively supported by SQLite, only Mac OSX 606** cares about the difference.) 607*/ 608#define SQLITE_SYNC_NORMAL 0x00002 609#define SQLITE_SYNC_FULL 0x00003 610#define SQLITE_SYNC_DATAONLY 0x00010 611 612/* 613** CAPI3REF: OS Interface Open File Handle 614** 615** An [sqlite3_file] object represents an open file in the 616** [sqlite3_vfs | OS interface layer]. Individual OS interface 617** implementations will 618** want to subclass this object by appending additional fields 619** for their own use. The pMethods entry is a pointer to an 620** [sqlite3_io_methods] object that defines methods for performing 621** I/O operations on the open file. 622*/ 623typedef struct sqlite3_file sqlite3_file; 624struct sqlite3_file { 625 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 626}; 627 628/* 629** CAPI3REF: OS Interface File Virtual Methods Object 630** 631** Every file opened by the [sqlite3_vfs.xOpen] method populates an 632** [sqlite3_file] object (or, more commonly, a subclass of the 633** [sqlite3_file] object) with a pointer to an instance of this object. 634** This object defines the methods used to perform various operations 635** against the open file represented by the [sqlite3_file] object. 636** 637** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 638** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 639** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 640** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 641** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 642** to NULL. 643** 644** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 645** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 646** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 647** flag may be ORed in to indicate that only the data of the file 648** and not its inode needs to be synced. 649** 650** The integer values to xLock() and xUnlock() are one of 651** <ul> 652** <li> [SQLITE_LOCK_NONE], 653** <li> [SQLITE_LOCK_SHARED], 654** <li> [SQLITE_LOCK_RESERVED], 655** <li> [SQLITE_LOCK_PENDING], or 656** <li> [SQLITE_LOCK_EXCLUSIVE]. 657** </ul> 658** xLock() increases the lock. xUnlock() decreases the lock. 659** The xCheckReservedLock() method checks whether any database connection, 660** either in this process or in some other process, is holding a RESERVED, 661** PENDING, or EXCLUSIVE lock on the file. It returns true 662** if such a lock exists and false otherwise. 663** 664** The xFileControl() method is a generic interface that allows custom 665** VFS implementations to directly control an open file using the 666** [sqlite3_file_control()] interface. The second "op" argument is an 667** integer opcode. The third argument is a generic pointer intended to 668** point to a structure that may contain arguments or space in which to 669** write return values. Potential uses for xFileControl() might be 670** functions to enable blocking locks with timeouts, to change the 671** locking strategy (for example to use dot-file locks), to inquire 672** about the status of a lock, or to break stale locks. The SQLite 673** core reserves all opcodes less than 100 for its own use. 674** A [file control opcodes | list of opcodes] less than 100 is available. 675** Applications that define a custom xFileControl method should use opcodes 676** greater than 100 to avoid conflicts. VFS implementations should 677** return [SQLITE_NOTFOUND] for file control opcodes that they do not 678** recognize. 679** 680** The xSectorSize() method returns the sector size of the 681** device that underlies the file. The sector size is the 682** minimum write that can be performed without disturbing 683** other bytes in the file. The xDeviceCharacteristics() 684** method returns a bit vector describing behaviors of the 685** underlying device: 686** 687** <ul> 688** <li> [SQLITE_IOCAP_ATOMIC] 689** <li> [SQLITE_IOCAP_ATOMIC512] 690** <li> [SQLITE_IOCAP_ATOMIC1K] 691** <li> [SQLITE_IOCAP_ATOMIC2K] 692** <li> [SQLITE_IOCAP_ATOMIC4K] 693** <li> [SQLITE_IOCAP_ATOMIC8K] 694** <li> [SQLITE_IOCAP_ATOMIC16K] 695** <li> [SQLITE_IOCAP_ATOMIC32K] 696** <li> [SQLITE_IOCAP_ATOMIC64K] 697** <li> [SQLITE_IOCAP_SAFE_APPEND] 698** <li> [SQLITE_IOCAP_SEQUENTIAL] 699** </ul> 700** 701** The SQLITE_IOCAP_ATOMIC property means that all writes of 702** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 703** mean that writes of blocks that are nnn bytes in size and 704** are aligned to an address which is an integer multiple of 705** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 706** that when data is appended to a file, the data is appended 707** first then the size of the file is extended, never the other 708** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 709** information is written to disk in the same order as calls 710** to xWrite(). 711** 712** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 713** in the unread portions of the buffer with zeros. A VFS that 714** fails to zero-fill short reads might seem to work. However, 715** failure to zero-fill short reads will eventually lead to 716** database corruption. 717*/ 718typedef struct sqlite3_io_methods sqlite3_io_methods; 719struct sqlite3_io_methods { 720 int iVersion; 721 int (*xClose)(sqlite3_file*); 722 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 723 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 724 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 725 int (*xSync)(sqlite3_file*, int flags); 726 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 727 int (*xLock)(sqlite3_file*, int); 728 int (*xUnlock)(sqlite3_file*, int); 729 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 730 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 731 int (*xSectorSize)(sqlite3_file*); 732 int (*xDeviceCharacteristics)(sqlite3_file*); 733 /* Methods above are valid for version 1 */ 734 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 735 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 736 void (*xShmBarrier)(sqlite3_file*); 737 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 738 /* Methods above are valid for version 2 */ 739 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 740 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 741 /* Methods above are valid for version 3 */ 742 /* Additional methods may be added in future releases */ 743}; 744 745/* 746** CAPI3REF: Standard File Control Opcodes 747** KEYWORDS: {file control opcodes} {file control opcode} 748** 749** These integer constants are opcodes for the xFileControl method 750** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 751** interface. 752** 753** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 754** opcode causes the xFileControl method to write the current state of 755** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 756** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 757** into an integer that the pArg argument points to. This capability 758** is used during testing and only needs to be supported when SQLITE_TEST 759** is defined. 760** <ul> 761** <li>[[SQLITE_FCNTL_SIZE_HINT]] 762** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 763** layer a hint of how large the database file will grow to be during the 764** current transaction. This hint is not guaranteed to be accurate but it 765** is often close. The underlying VFS might choose to preallocate database 766** file space based on this hint in order to help writes to the database 767** file run faster. 768** 769** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 770** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 771** extends and truncates the database file in chunks of a size specified 772** by the user. The fourth argument to [sqlite3_file_control()] should 773** point to an integer (type int) containing the new chunk-size to use 774** for the nominated database. Allocating database file space in large 775** chunks (say 1MB at a time), may reduce file-system fragmentation and 776** improve performance on some systems. 777** 778** <li>[[SQLITE_FCNTL_FILE_POINTER]] 779** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 780** to the [sqlite3_file] object associated with a particular database 781** connection. See the [sqlite3_file_control()] documentation for 782** additional information. 783** 784** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 785** No longer in use. 786** 787** <li>[[SQLITE_FCNTL_SYNC]] 788** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 789** sent to the VFS immediately before the xSync method is invoked on a 790** database file descriptor. Or, if the xSync method is not invoked 791** because the user has configured SQLite with 792** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 793** of the xSync method. In most cases, the pointer argument passed with 794** this file-control is NULL. However, if the database file is being synced 795** as part of a multi-database commit, the argument points to a nul-terminated 796** string containing the transactions master-journal file name. VFSes that 797** do not need this signal should silently ignore this opcode. Applications 798** should not call [sqlite3_file_control()] with this opcode as doing so may 799** disrupt the operation of the specialized VFSes that do require it. 800** 801** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 802** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 803** and sent to the VFS after a transaction has been committed immediately 804** but before the database is unlocked. VFSes that do not need this signal 805** should silently ignore this opcode. Applications should not call 806** [sqlite3_file_control()] with this opcode as doing so may disrupt the 807** operation of the specialized VFSes that do require it. 808** 809** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 810** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 811** retry counts and intervals for certain disk I/O operations for the 812** windows [VFS] in order to provide robustness in the presence of 813** anti-virus programs. By default, the windows VFS will retry file read, 814** file write, and file delete operations up to 10 times, with a delay 815** of 25 milliseconds before the first retry and with the delay increasing 816** by an additional 25 milliseconds with each subsequent retry. This 817** opcode allows these two values (10 retries and 25 milliseconds of delay) 818** to be adjusted. The values are changed for all database connections 819** within the same process. The argument is a pointer to an array of two 820** integers where the first integer i the new retry count and the second 821** integer is the delay. If either integer is negative, then the setting 822** is not changed but instead the prior value of that setting is written 823** into the array entry, allowing the current retry settings to be 824** interrogated. The zDbName parameter is ignored. 825** 826** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 827** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 828** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 829** write ahead log and shared memory files used for transaction control 830** are automatically deleted when the latest connection to the database 831** closes. Setting persistent WAL mode causes those files to persist after 832** close. Persisting the files is useful when other processes that do not 833** have write permission on the directory containing the database file want 834** to read the database file, as the WAL and shared memory files must exist 835** in order for the database to be readable. The fourth parameter to 836** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 837** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 838** WAL mode. If the integer is -1, then it is overwritten with the current 839** WAL persistence setting. 840** 841** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 842** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 843** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 844** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 845** xDeviceCharacteristics methods. The fourth parameter to 846** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 847** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 848** mode. If the integer is -1, then it is overwritten with the current 849** zero-damage mode setting. 850** 851** <li>[[SQLITE_FCNTL_OVERWRITE]] 852** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 853** a write transaction to indicate that, unless it is rolled back for some 854** reason, the entire database file will be overwritten by the current 855** transaction. This is used by VACUUM operations. 856** 857** <li>[[SQLITE_FCNTL_VFSNAME]] 858** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 859** all [VFSes] in the VFS stack. The names are of all VFS shims and the 860** final bottom-level VFS are written into memory obtained from 861** [sqlite3_malloc()] and the result is stored in the char* variable 862** that the fourth parameter of [sqlite3_file_control()] points to. 863** The caller is responsible for freeing the memory when done. As with 864** all file-control actions, there is no guarantee that this will actually 865** do anything. Callers should initialize the char* variable to a NULL 866** pointer in case this file-control is not implemented. This file-control 867** is intended for diagnostic use only. 868** 869** <li>[[SQLITE_FCNTL_PRAGMA]] 870** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 871** file control is sent to the open [sqlite3_file] object corresponding 872** to the database file to which the pragma statement refers. ^The argument 873** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 874** pointers to strings (char**) in which the second element of the array 875** is the name of the pragma and the third element is the argument to the 876** pragma or NULL if the pragma has no argument. ^The handler for an 877** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 878** of the char** argument point to a string obtained from [sqlite3_mprintf()] 879** or the equivalent and that string will become the result of the pragma or 880** the error message if the pragma fails. ^If the 881** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 882** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 883** file control returns [SQLITE_OK], then the parser assumes that the 884** VFS has handled the PRAGMA itself and the parser generates a no-op 885** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 886** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 887** that the VFS encountered an error while handling the [PRAGMA] and the 888** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 889** file control occurs at the beginning of pragma statement analysis and so 890** it is able to override built-in [PRAGMA] statements. 891** 892** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 893** ^The [SQLITE_FCNTL_BUSYHANDLER] 894** file-control may be invoked by SQLite on the database file handle 895** shortly after it is opened in order to provide a custom VFS with access 896** to the connections busy-handler callback. The argument is of type (void **) 897** - an array of two (void *) values. The first (void *) actually points 898** to a function of type (int (*)(void *)). In order to invoke the connections 899** busy-handler, this function should be invoked with the second (void *) in 900** the array as the only argument. If it returns non-zero, then the operation 901** should be retried. If it returns zero, the custom VFS should abandon the 902** current operation. 903** 904** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 905** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 906** to have SQLite generate a 907** temporary filename using the same algorithm that is followed to generate 908** temporary filenames for TEMP tables and other internal uses. The 909** argument should be a char** which will be filled with the filename 910** written into memory obtained from [sqlite3_malloc()]. The caller should 911** invoke [sqlite3_free()] on the result to avoid a memory leak. 912** 913** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 914** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 915** maximum number of bytes that will be used for memory-mapped I/O. 916** The argument is a pointer to a value of type sqlite3_int64 that 917** is an advisory maximum number of bytes in the file to memory map. The 918** pointer is overwritten with the old value. The limit is not changed if 919** the value originally pointed to is negative, and so the current limit 920** can be queried by passing in a pointer to a negative number. This 921** file-control is used internally to implement [PRAGMA mmap_size]. 922** 923** <li>[[SQLITE_FCNTL_TRACE]] 924** The [SQLITE_FCNTL_TRACE] file control provides advisory information 925** to the VFS about what the higher layers of the SQLite stack are doing. 926** This file control is used by some VFS activity tracing [shims]. 927** The argument is a zero-terminated string. Higher layers in the 928** SQLite stack may generate instances of this file control if 929** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 930** 931** <li>[[SQLITE_FCNTL_HAS_MOVED]] 932** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 933** pointer to an integer and it writes a boolean into that integer depending 934** on whether or not the file has been renamed, moved, or deleted since it 935** was first opened. 936** 937** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 938** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 939** opcode causes the xFileControl method to swap the file handle with the one 940** pointed to by the pArg argument. This capability is used during testing 941** and only needs to be supported when SQLITE_TEST is defined. 942** 943** </ul> 944*/ 945#define SQLITE_FCNTL_LOCKSTATE 1 946#define SQLITE_GET_LOCKPROXYFILE 2 947#define SQLITE_SET_LOCKPROXYFILE 3 948#define SQLITE_LAST_ERRNO 4 949#define SQLITE_FCNTL_SIZE_HINT 5 950#define SQLITE_FCNTL_CHUNK_SIZE 6 951#define SQLITE_FCNTL_FILE_POINTER 7 952#define SQLITE_FCNTL_SYNC_OMITTED 8 953#define SQLITE_FCNTL_WIN32_AV_RETRY 9 954#define SQLITE_FCNTL_PERSIST_WAL 10 955#define SQLITE_FCNTL_OVERWRITE 11 956#define SQLITE_FCNTL_VFSNAME 12 957#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 958#define SQLITE_FCNTL_PRAGMA 14 959#define SQLITE_FCNTL_BUSYHANDLER 15 960#define SQLITE_FCNTL_TEMPFILENAME 16 961#define SQLITE_FCNTL_MMAP_SIZE 18 962#define SQLITE_FCNTL_TRACE 19 963#define SQLITE_FCNTL_HAS_MOVED 20 964#define SQLITE_FCNTL_SYNC 21 965#define SQLITE_FCNTL_COMMIT_PHASETWO 22 966#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 967 968/* 969** CAPI3REF: Mutex Handle 970** 971** The mutex module within SQLite defines [sqlite3_mutex] to be an 972** abstract type for a mutex object. The SQLite core never looks 973** at the internal representation of an [sqlite3_mutex]. It only 974** deals with pointers to the [sqlite3_mutex] object. 975** 976** Mutexes are created using [sqlite3_mutex_alloc()]. 977*/ 978typedef struct sqlite3_mutex sqlite3_mutex; 979 980/* 981** CAPI3REF: OS Interface Object 982** 983** An instance of the sqlite3_vfs object defines the interface between 984** the SQLite core and the underlying operating system. The "vfs" 985** in the name of the object stands for "virtual file system". See 986** the [VFS | VFS documentation] for further information. 987** 988** The value of the iVersion field is initially 1 but may be larger in 989** future versions of SQLite. Additional fields may be appended to this 990** object when the iVersion value is increased. Note that the structure 991** of the sqlite3_vfs object changes in the transaction between 992** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 993** modified. 994** 995** The szOsFile field is the size of the subclassed [sqlite3_file] 996** structure used by this VFS. mxPathname is the maximum length of 997** a pathname in this VFS. 998** 999** Registered sqlite3_vfs objects are kept on a linked list formed by 1000** the pNext pointer. The [sqlite3_vfs_register()] 1001** and [sqlite3_vfs_unregister()] interfaces manage this list 1002** in a thread-safe way. The [sqlite3_vfs_find()] interface 1003** searches the list. Neither the application code nor the VFS 1004** implementation should use the pNext pointer. 1005** 1006** The pNext field is the only field in the sqlite3_vfs 1007** structure that SQLite will ever modify. SQLite will only access 1008** or modify this field while holding a particular static mutex. 1009** The application should never modify anything within the sqlite3_vfs 1010** object once the object has been registered. 1011** 1012** The zName field holds the name of the VFS module. The name must 1013** be unique across all VFS modules. 1014** 1015** [[sqlite3_vfs.xOpen]] 1016** ^SQLite guarantees that the zFilename parameter to xOpen 1017** is either a NULL pointer or string obtained 1018** from xFullPathname() with an optional suffix added. 1019** ^If a suffix is added to the zFilename parameter, it will 1020** consist of a single "-" character followed by no more than 1021** 11 alphanumeric and/or "-" characters. 1022** ^SQLite further guarantees that 1023** the string will be valid and unchanged until xClose() is 1024** called. Because of the previous sentence, 1025** the [sqlite3_file] can safely store a pointer to the 1026** filename if it needs to remember the filename for some reason. 1027** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1028** must invent its own temporary name for the file. ^Whenever the 1029** xFilename parameter is NULL it will also be the case that the 1030** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1031** 1032** The flags argument to xOpen() includes all bits set in 1033** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1034** or [sqlite3_open16()] is used, then flags includes at least 1035** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1036** If xOpen() opens a file read-only then it sets *pOutFlags to 1037** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1038** 1039** ^(SQLite will also add one of the following flags to the xOpen() 1040** call, depending on the object being opened: 1041** 1042** <ul> 1043** <li> [SQLITE_OPEN_MAIN_DB] 1044** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1045** <li> [SQLITE_OPEN_TEMP_DB] 1046** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1047** <li> [SQLITE_OPEN_TRANSIENT_DB] 1048** <li> [SQLITE_OPEN_SUBJOURNAL] 1049** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1050** <li> [SQLITE_OPEN_WAL] 1051** </ul>)^ 1052** 1053** The file I/O implementation can use the object type flags to 1054** change the way it deals with files. For example, an application 1055** that does not care about crash recovery or rollback might make 1056** the open of a journal file a no-op. Writes to this journal would 1057** also be no-ops, and any attempt to read the journal would return 1058** SQLITE_IOERR. Or the implementation might recognize that a database 1059** file will be doing page-aligned sector reads and writes in a random 1060** order and set up its I/O subsystem accordingly. 1061** 1062** SQLite might also add one of the following flags to the xOpen method: 1063** 1064** <ul> 1065** <li> [SQLITE_OPEN_DELETEONCLOSE] 1066** <li> [SQLITE_OPEN_EXCLUSIVE] 1067** </ul> 1068** 1069** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1070** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1071** will be set for TEMP databases and their journals, transient 1072** databases, and subjournals. 1073** 1074** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1075** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1076** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1077** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1078** SQLITE_OPEN_CREATE, is used to indicate that file should always 1079** be created, and that it is an error if it already exists. 1080** It is <i>not</i> used to indicate the file should be opened 1081** for exclusive access. 1082** 1083** ^At least szOsFile bytes of memory are allocated by SQLite 1084** to hold the [sqlite3_file] structure passed as the third 1085** argument to xOpen. The xOpen method does not have to 1086** allocate the structure; it should just fill it in. Note that 1087** the xOpen method must set the sqlite3_file.pMethods to either 1088** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1089** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1090** element will be valid after xOpen returns regardless of the success 1091** or failure of the xOpen call. 1092** 1093** [[sqlite3_vfs.xAccess]] 1094** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1095** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1096** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1097** to test whether a file is at least readable. The file can be a 1098** directory. 1099** 1100** ^SQLite will always allocate at least mxPathname+1 bytes for the 1101** output buffer xFullPathname. The exact size of the output buffer 1102** is also passed as a parameter to both methods. If the output buffer 1103** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1104** handled as a fatal error by SQLite, vfs implementations should endeavor 1105** to prevent this by setting mxPathname to a sufficiently large value. 1106** 1107** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1108** interfaces are not strictly a part of the filesystem, but they are 1109** included in the VFS structure for completeness. 1110** The xRandomness() function attempts to return nBytes bytes 1111** of good-quality randomness into zOut. The return value is 1112** the actual number of bytes of randomness obtained. 1113** The xSleep() method causes the calling thread to sleep for at 1114** least the number of microseconds given. ^The xCurrentTime() 1115** method returns a Julian Day Number for the current date and time as 1116** a floating point value. 1117** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1118** Day Number multiplied by 86400000 (the number of milliseconds in 1119** a 24-hour day). 1120** ^SQLite will use the xCurrentTimeInt64() method to get the current 1121** date and time if that method is available (if iVersion is 2 or 1122** greater and the function pointer is not NULL) and will fall back 1123** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1124** 1125** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1126** are not used by the SQLite core. These optional interfaces are provided 1127** by some VFSes to facilitate testing of the VFS code. By overriding 1128** system calls with functions under its control, a test program can 1129** simulate faults and error conditions that would otherwise be difficult 1130** or impossible to induce. The set of system calls that can be overridden 1131** varies from one VFS to another, and from one version of the same VFS to the 1132** next. Applications that use these interfaces must be prepared for any 1133** or all of these interfaces to be NULL or for their behavior to change 1134** from one release to the next. Applications must not attempt to access 1135** any of these methods if the iVersion of the VFS is less than 3. 1136*/ 1137typedef struct sqlite3_vfs sqlite3_vfs; 1138typedef void (*sqlite3_syscall_ptr)(void); 1139struct sqlite3_vfs { 1140 int iVersion; /* Structure version number (currently 3) */ 1141 int szOsFile; /* Size of subclassed sqlite3_file */ 1142 int mxPathname; /* Maximum file pathname length */ 1143 sqlite3_vfs *pNext; /* Next registered VFS */ 1144 const char *zName; /* Name of this virtual file system */ 1145 void *pAppData; /* Pointer to application-specific data */ 1146 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1147 int flags, int *pOutFlags); 1148 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1149 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1150 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1151 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1152 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1153 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1154 void (*xDlClose)(sqlite3_vfs*, void*); 1155 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1156 int (*xSleep)(sqlite3_vfs*, int microseconds); 1157 int (*xCurrentTime)(sqlite3_vfs*, double*); 1158 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1159 /* 1160 ** The methods above are in version 1 of the sqlite_vfs object 1161 ** definition. Those that follow are added in version 2 or later 1162 */ 1163 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1164 /* 1165 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1166 ** Those below are for version 3 and greater. 1167 */ 1168 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1169 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1170 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1171 /* 1172 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1173 ** New fields may be appended in figure versions. The iVersion 1174 ** value will increment whenever this happens. 1175 */ 1176}; 1177 1178/* 1179** CAPI3REF: Flags for the xAccess VFS method 1180** 1181** These integer constants can be used as the third parameter to 1182** the xAccess method of an [sqlite3_vfs] object. They determine 1183** what kind of permissions the xAccess method is looking for. 1184** With SQLITE_ACCESS_EXISTS, the xAccess method 1185** simply checks whether the file exists. 1186** With SQLITE_ACCESS_READWRITE, the xAccess method 1187** checks whether the named directory is both readable and writable 1188** (in other words, if files can be added, removed, and renamed within 1189** the directory). 1190** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1191** [temp_store_directory pragma], though this could change in a future 1192** release of SQLite. 1193** With SQLITE_ACCESS_READ, the xAccess method 1194** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1195** currently unused, though it might be used in a future release of 1196** SQLite. 1197*/ 1198#define SQLITE_ACCESS_EXISTS 0 1199#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1200#define SQLITE_ACCESS_READ 2 /* Unused */ 1201 1202/* 1203** CAPI3REF: Flags for the xShmLock VFS method 1204** 1205** These integer constants define the various locking operations 1206** allowed by the xShmLock method of [sqlite3_io_methods]. The 1207** following are the only legal combinations of flags to the 1208** xShmLock method: 1209** 1210** <ul> 1211** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1212** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1213** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1214** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1215** </ul> 1216** 1217** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1218** was given no the corresponding lock. 1219** 1220** The xShmLock method can transition between unlocked and SHARED or 1221** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1222** and EXCLUSIVE. 1223*/ 1224#define SQLITE_SHM_UNLOCK 1 1225#define SQLITE_SHM_LOCK 2 1226#define SQLITE_SHM_SHARED 4 1227#define SQLITE_SHM_EXCLUSIVE 8 1228 1229/* 1230** CAPI3REF: Maximum xShmLock index 1231** 1232** The xShmLock method on [sqlite3_io_methods] may use values 1233** between 0 and this upper bound as its "offset" argument. 1234** The SQLite core will never attempt to acquire or release a 1235** lock outside of this range 1236*/ 1237#define SQLITE_SHM_NLOCK 8 1238 1239 1240/* 1241** CAPI3REF: Initialize The SQLite Library 1242** 1243** ^The sqlite3_initialize() routine initializes the 1244** SQLite library. ^The sqlite3_shutdown() routine 1245** deallocates any resources that were allocated by sqlite3_initialize(). 1246** These routines are designed to aid in process initialization and 1247** shutdown on embedded systems. Workstation applications using 1248** SQLite normally do not need to invoke either of these routines. 1249** 1250** A call to sqlite3_initialize() is an "effective" call if it is 1251** the first time sqlite3_initialize() is invoked during the lifetime of 1252** the process, or if it is the first time sqlite3_initialize() is invoked 1253** following a call to sqlite3_shutdown(). ^(Only an effective call 1254** of sqlite3_initialize() does any initialization. All other calls 1255** are harmless no-ops.)^ 1256** 1257** A call to sqlite3_shutdown() is an "effective" call if it is the first 1258** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1259** an effective call to sqlite3_shutdown() does any deinitialization. 1260** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1261** 1262** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1263** is not. The sqlite3_shutdown() interface must only be called from a 1264** single thread. All open [database connections] must be closed and all 1265** other SQLite resources must be deallocated prior to invoking 1266** sqlite3_shutdown(). 1267** 1268** Among other things, ^sqlite3_initialize() will invoke 1269** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1270** will invoke sqlite3_os_end(). 1271** 1272** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1273** ^If for some reason, sqlite3_initialize() is unable to initialize 1274** the library (perhaps it is unable to allocate a needed resource such 1275** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1276** 1277** ^The sqlite3_initialize() routine is called internally by many other 1278** SQLite interfaces so that an application usually does not need to 1279** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1280** calls sqlite3_initialize() so the SQLite library will be automatically 1281** initialized when [sqlite3_open()] is called if it has not be initialized 1282** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1283** compile-time option, then the automatic calls to sqlite3_initialize() 1284** are omitted and the application must call sqlite3_initialize() directly 1285** prior to using any other SQLite interface. For maximum portability, 1286** it is recommended that applications always invoke sqlite3_initialize() 1287** directly prior to using any other SQLite interface. Future releases 1288** of SQLite may require this. In other words, the behavior exhibited 1289** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1290** default behavior in some future release of SQLite. 1291** 1292** The sqlite3_os_init() routine does operating-system specific 1293** initialization of the SQLite library. The sqlite3_os_end() 1294** routine undoes the effect of sqlite3_os_init(). Typical tasks 1295** performed by these routines include allocation or deallocation 1296** of static resources, initialization of global variables, 1297** setting up a default [sqlite3_vfs] module, or setting up 1298** a default configuration using [sqlite3_config()]. 1299** 1300** The application should never invoke either sqlite3_os_init() 1301** or sqlite3_os_end() directly. The application should only invoke 1302** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1303** interface is called automatically by sqlite3_initialize() and 1304** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1305** implementations for sqlite3_os_init() and sqlite3_os_end() 1306** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1307** When [custom builds | built for other platforms] 1308** (using the [SQLITE_OS_OTHER=1] compile-time 1309** option) the application must supply a suitable implementation for 1310** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1311** implementation of sqlite3_os_init() or sqlite3_os_end() 1312** must return [SQLITE_OK] on success and some other [error code] upon 1313** failure. 1314*/ 1315int sqlite3_initialize(void); 1316int sqlite3_shutdown(void); 1317int sqlite3_os_init(void); 1318int sqlite3_os_end(void); 1319 1320/* 1321** CAPI3REF: Configuring The SQLite Library 1322** 1323** The sqlite3_config() interface is used to make global configuration 1324** changes to SQLite in order to tune SQLite to the specific needs of 1325** the application. The default configuration is recommended for most 1326** applications and so this routine is usually not necessary. It is 1327** provided to support rare applications with unusual needs. 1328** 1329** The sqlite3_config() interface is not threadsafe. The application 1330** must insure that no other SQLite interfaces are invoked by other 1331** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1332** may only be invoked prior to library initialization using 1333** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1334** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1335** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1336** Note, however, that ^sqlite3_config() can be called as part of the 1337** implementation of an application-defined [sqlite3_os_init()]. 1338** 1339** The first argument to sqlite3_config() is an integer 1340** [configuration option] that determines 1341** what property of SQLite is to be configured. Subsequent arguments 1342** vary depending on the [configuration option] 1343** in the first argument. 1344** 1345** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1346** ^If the option is unknown or SQLite is unable to set the option 1347** then this routine returns a non-zero [error code]. 1348*/ 1349int sqlite3_config(int, ...); 1350 1351/* 1352** CAPI3REF: Configure database connections 1353** 1354** The sqlite3_db_config() interface is used to make configuration 1355** changes to a [database connection]. The interface is similar to 1356** [sqlite3_config()] except that the changes apply to a single 1357** [database connection] (specified in the first argument). 1358** 1359** The second argument to sqlite3_db_config(D,V,...) is the 1360** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1361** that indicates what aspect of the [database connection] is being configured. 1362** Subsequent arguments vary depending on the configuration verb. 1363** 1364** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1365** the call is considered successful. 1366*/ 1367int sqlite3_db_config(sqlite3*, int op, ...); 1368 1369/* 1370** CAPI3REF: Memory Allocation Routines 1371** 1372** An instance of this object defines the interface between SQLite 1373** and low-level memory allocation routines. 1374** 1375** This object is used in only one place in the SQLite interface. 1376** A pointer to an instance of this object is the argument to 1377** [sqlite3_config()] when the configuration option is 1378** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1379** By creating an instance of this object 1380** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1381** during configuration, an application can specify an alternative 1382** memory allocation subsystem for SQLite to use for all of its 1383** dynamic memory needs. 1384** 1385** Note that SQLite comes with several [built-in memory allocators] 1386** that are perfectly adequate for the overwhelming majority of applications 1387** and that this object is only useful to a tiny minority of applications 1388** with specialized memory allocation requirements. This object is 1389** also used during testing of SQLite in order to specify an alternative 1390** memory allocator that simulates memory out-of-memory conditions in 1391** order to verify that SQLite recovers gracefully from such 1392** conditions. 1393** 1394** The xMalloc, xRealloc, and xFree methods must work like the 1395** malloc(), realloc() and free() functions from the standard C library. 1396** ^SQLite guarantees that the second argument to 1397** xRealloc is always a value returned by a prior call to xRoundup. 1398** 1399** xSize should return the allocated size of a memory allocation 1400** previously obtained from xMalloc or xRealloc. The allocated size 1401** is always at least as big as the requested size but may be larger. 1402** 1403** The xRoundup method returns what would be the allocated size of 1404** a memory allocation given a particular requested size. Most memory 1405** allocators round up memory allocations at least to the next multiple 1406** of 8. Some allocators round up to a larger multiple or to a power of 2. 1407** Every memory allocation request coming in through [sqlite3_malloc()] 1408** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1409** that causes the corresponding memory allocation to fail. 1410** 1411** The xInit method initializes the memory allocator. For example, 1412** it might allocate any require mutexes or initialize internal data 1413** structures. The xShutdown method is invoked (indirectly) by 1414** [sqlite3_shutdown()] and should deallocate any resources acquired 1415** by xInit. The pAppData pointer is used as the only parameter to 1416** xInit and xShutdown. 1417** 1418** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1419** the xInit method, so the xInit method need not be threadsafe. The 1420** xShutdown method is only called from [sqlite3_shutdown()] so it does 1421** not need to be threadsafe either. For all other methods, SQLite 1422** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1423** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1424** it is by default) and so the methods are automatically serialized. 1425** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1426** methods must be threadsafe or else make their own arrangements for 1427** serialization. 1428** 1429** SQLite will never invoke xInit() more than once without an intervening 1430** call to xShutdown(). 1431*/ 1432typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1433struct sqlite3_mem_methods { 1434 void *(*xMalloc)(int); /* Memory allocation function */ 1435 void (*xFree)(void*); /* Free a prior allocation */ 1436 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1437 int (*xSize)(void*); /* Return the size of an allocation */ 1438 int (*xRoundup)(int); /* Round up request size to allocation size */ 1439 int (*xInit)(void*); /* Initialize the memory allocator */ 1440 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1441 void *pAppData; /* Argument to xInit() and xShutdown() */ 1442}; 1443 1444/* 1445** CAPI3REF: Configuration Options 1446** KEYWORDS: {configuration option} 1447** 1448** These constants are the available integer configuration options that 1449** can be passed as the first argument to the [sqlite3_config()] interface. 1450** 1451** New configuration options may be added in future releases of SQLite. 1452** Existing configuration options might be discontinued. Applications 1453** should check the return code from [sqlite3_config()] to make sure that 1454** the call worked. The [sqlite3_config()] interface will return a 1455** non-zero [error code] if a discontinued or unsupported configuration option 1456** is invoked. 1457** 1458** <dl> 1459** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1460** <dd>There are no arguments to this option. ^This option sets the 1461** [threading mode] to Single-thread. In other words, it disables 1462** all mutexing and puts SQLite into a mode where it can only be used 1463** by a single thread. ^If SQLite is compiled with 1464** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1465** it is not possible to change the [threading mode] from its default 1466** value of Single-thread and so [sqlite3_config()] will return 1467** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1468** configuration option.</dd> 1469** 1470** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1471** <dd>There are no arguments to this option. ^This option sets the 1472** [threading mode] to Multi-thread. In other words, it disables 1473** mutexing on [database connection] and [prepared statement] objects. 1474** The application is responsible for serializing access to 1475** [database connections] and [prepared statements]. But other mutexes 1476** are enabled so that SQLite will be safe to use in a multi-threaded 1477** environment as long as no two threads attempt to use the same 1478** [database connection] at the same time. ^If SQLite is compiled with 1479** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1480** it is not possible to set the Multi-thread [threading mode] and 1481** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1482** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1483** 1484** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1485** <dd>There are no arguments to this option. ^This option sets the 1486** [threading mode] to Serialized. In other words, this option enables 1487** all mutexes including the recursive 1488** mutexes on [database connection] and [prepared statement] objects. 1489** In this mode (which is the default when SQLite is compiled with 1490** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1491** to [database connections] and [prepared statements] so that the 1492** application is free to use the same [database connection] or the 1493** same [prepared statement] in different threads at the same time. 1494** ^If SQLite is compiled with 1495** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1496** it is not possible to set the Serialized [threading mode] and 1497** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1498** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1499** 1500** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1501** <dd> ^(This option takes a single argument which is a pointer to an 1502** instance of the [sqlite3_mem_methods] structure. The argument specifies 1503** alternative low-level memory allocation routines to be used in place of 1504** the memory allocation routines built into SQLite.)^ ^SQLite makes 1505** its own private copy of the content of the [sqlite3_mem_methods] structure 1506** before the [sqlite3_config()] call returns.</dd> 1507** 1508** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1509** <dd> ^(This option takes a single argument which is a pointer to an 1510** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1511** structure is filled with the currently defined memory allocation routines.)^ 1512** This option can be used to overload the default memory allocation 1513** routines with a wrapper that simulations memory allocation failure or 1514** tracks memory usage, for example. </dd> 1515** 1516** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1517** <dd> ^This option takes single argument of type int, interpreted as a 1518** boolean, which enables or disables the collection of memory allocation 1519** statistics. ^(When memory allocation statistics are disabled, the 1520** following SQLite interfaces become non-operational: 1521** <ul> 1522** <li> [sqlite3_memory_used()] 1523** <li> [sqlite3_memory_highwater()] 1524** <li> [sqlite3_soft_heap_limit64()] 1525** <li> [sqlite3_status()] 1526** </ul>)^ 1527** ^Memory allocation statistics are enabled by default unless SQLite is 1528** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1529** allocation statistics are disabled by default. 1530** </dd> 1531** 1532** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1533** <dd> ^This option specifies a static memory buffer that SQLite can use for 1534** scratch memory. There are three arguments: A pointer an 8-byte 1535** aligned memory buffer from which the scratch allocations will be 1536** drawn, the size of each scratch allocation (sz), 1537** and the maximum number of scratch allocations (N). The sz 1538** argument must be a multiple of 16. 1539** The first argument must be a pointer to an 8-byte aligned buffer 1540** of at least sz*N bytes of memory. 1541** ^SQLite will use no more than two scratch buffers per thread. So 1542** N should be set to twice the expected maximum number of threads. 1543** ^SQLite will never require a scratch buffer that is more than 6 1544** times the database page size. ^If SQLite needs needs additional 1545** scratch memory beyond what is provided by this configuration option, then 1546** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1547** 1548** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1549** <dd> ^This option specifies a static memory buffer that SQLite can use for 1550** the database page cache with the default page cache implementation. 1551** This configuration should not be used if an application-define page 1552** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1553** There are three arguments to this option: A pointer to 8-byte aligned 1554** memory, the size of each page buffer (sz), and the number of pages (N). 1555** The sz argument should be the size of the largest database page 1556** (a power of two between 512 and 32768) plus a little extra for each 1557** page header. ^The page header size is 20 to 40 bytes depending on 1558** the host architecture. ^It is harmless, apart from the wasted memory, 1559** to make sz a little too large. The first 1560** argument should point to an allocation of at least sz*N bytes of memory. 1561** ^SQLite will use the memory provided by the first argument to satisfy its 1562** memory needs for the first N pages that it adds to cache. ^If additional 1563** page cache memory is needed beyond what is provided by this option, then 1564** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1565** The pointer in the first argument must 1566** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1567** will be undefined.</dd> 1568** 1569** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1570** <dd> ^This option specifies a static memory buffer that SQLite will use 1571** for all of its dynamic memory allocation needs beyond those provided 1572** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1573** There are three arguments: An 8-byte aligned pointer to the memory, 1574** the number of bytes in the memory buffer, and the minimum allocation size. 1575** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1576** to using its default memory allocator (the system malloc() implementation), 1577** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1578** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1579** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1580** allocator is engaged to handle all of SQLites memory allocation needs. 1581** The first pointer (the memory pointer) must be aligned to an 8-byte 1582** boundary or subsequent behavior of SQLite will be undefined. 1583** The minimum allocation size is capped at 2**12. Reasonable values 1584** for the minimum allocation size are 2**5 through 2**8.</dd> 1585** 1586** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1587** <dd> ^(This option takes a single argument which is a pointer to an 1588** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1589** alternative low-level mutex routines to be used in place 1590** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1591** content of the [sqlite3_mutex_methods] structure before the call to 1592** [sqlite3_config()] returns. ^If SQLite is compiled with 1593** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1594** the entire mutexing subsystem is omitted from the build and hence calls to 1595** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1596** return [SQLITE_ERROR].</dd> 1597** 1598** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1599** <dd> ^(This option takes a single argument which is a pointer to an 1600** instance of the [sqlite3_mutex_methods] structure. The 1601** [sqlite3_mutex_methods] 1602** structure is filled with the currently defined mutex routines.)^ 1603** This option can be used to overload the default mutex allocation 1604** routines with a wrapper used to track mutex usage for performance 1605** profiling or testing, for example. ^If SQLite is compiled with 1606** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1607** the entire mutexing subsystem is omitted from the build and hence calls to 1608** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1609** return [SQLITE_ERROR].</dd> 1610** 1611** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1612** <dd> ^(This option takes two arguments that determine the default 1613** memory allocation for the lookaside memory allocator on each 1614** [database connection]. The first argument is the 1615** size of each lookaside buffer slot and the second is the number of 1616** slots allocated to each database connection.)^ ^(This option sets the 1617** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1618** verb to [sqlite3_db_config()] can be used to change the lookaside 1619** configuration on individual connections.)^ </dd> 1620** 1621** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1622** <dd> ^(This option takes a single argument which is a pointer to 1623** an [sqlite3_pcache_methods2] object. This object specifies the interface 1624** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1625** object and uses it for page cache memory allocations.</dd> 1626** 1627** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1628** <dd> ^(This option takes a single argument which is a pointer to an 1629** [sqlite3_pcache_methods2] object. SQLite copies of the current 1630** page cache implementation into that object.)^ </dd> 1631** 1632** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1633** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1634** global [error log]. 1635** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1636** function with a call signature of void(*)(void*,int,const char*), 1637** and a pointer to void. ^If the function pointer is not NULL, it is 1638** invoked by [sqlite3_log()] to process each logging event. ^If the 1639** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1640** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1641** passed through as the first parameter to the application-defined logger 1642** function whenever that function is invoked. ^The second parameter to 1643** the logger function is a copy of the first parameter to the corresponding 1644** [sqlite3_log()] call and is intended to be a [result code] or an 1645** [extended result code]. ^The third parameter passed to the logger is 1646** log message after formatting via [sqlite3_snprintf()]. 1647** The SQLite logging interface is not reentrant; the logger function 1648** supplied by the application must not invoke any SQLite interface. 1649** In a multi-threaded application, the application-defined logger 1650** function must be threadsafe. </dd> 1651** 1652** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1653** <dd>^(This option takes a single argument of type int. If non-zero, then 1654** URI handling is globally enabled. If the parameter is zero, then URI handling 1655** is globally disabled.)^ ^If URI handling is globally enabled, all filenames 1656** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1657** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1658** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1659** connection is opened. ^If it is globally disabled, filenames are 1660** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1661** database connection is opened. ^(By default, URI handling is globally 1662** disabled. The default value may be changed by compiling with the 1663** [SQLITE_USE_URI] symbol defined.)^ 1664** 1665** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1666** <dd>^This option takes a single integer argument which is interpreted as 1667** a boolean in order to enable or disable the use of covering indices for 1668** full table scans in the query optimizer. ^The default setting is determined 1669** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1670** if that compile-time option is omitted. 1671** The ability to disable the use of covering indices for full table scans 1672** is because some incorrectly coded legacy applications might malfunction 1673** when the optimization is enabled. Providing the ability to 1674** disable the optimization allows the older, buggy application code to work 1675** without change even with newer versions of SQLite. 1676** 1677** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1678** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1679** <dd> These options are obsolete and should not be used by new code. 1680** They are retained for backwards compatibility but are now no-ops. 1681** </dd> 1682** 1683** [[SQLITE_CONFIG_SQLLOG]] 1684** <dt>SQLITE_CONFIG_SQLLOG 1685** <dd>This option is only available if sqlite is compiled with the 1686** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1687** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1688** The second should be of type (void*). The callback is invoked by the library 1689** in three separate circumstances, identified by the value passed as the 1690** fourth parameter. If the fourth parameter is 0, then the database connection 1691** passed as the second argument has just been opened. The third argument 1692** points to a buffer containing the name of the main database file. If the 1693** fourth parameter is 1, then the SQL statement that the third parameter 1694** points to has just been executed. Or, if the fourth parameter is 2, then 1695** the connection being passed as the second parameter is being closed. The 1696** third parameter is passed NULL In this case. An example of using this 1697** configuration option can be seen in the "test_sqllog.c" source file in 1698** the canonical SQLite source tree.</dd> 1699** 1700** [[SQLITE_CONFIG_MMAP_SIZE]] 1701** <dt>SQLITE_CONFIG_MMAP_SIZE 1702** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1703** that are the default mmap size limit (the default setting for 1704** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1705** ^The default setting can be overridden by each database connection using 1706** either the [PRAGMA mmap_size] command, or by using the 1707** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1708** cannot be changed at run-time. Nor may the maximum allowed mmap size 1709** exceed the compile-time maximum mmap size set by the 1710** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1711** ^If either argument to this option is negative, then that argument is 1712** changed to its compile-time default. 1713** 1714** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1715** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1716** <dd>^This option is only available if SQLite is compiled for Windows 1717** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. 1718** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1719** that specifies the maximum size of the created heap. 1720** </dl> 1721*/ 1722#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1723#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1724#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1725#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1726#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1727#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1728#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1729#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1730#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1731#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1732#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1733/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1734#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1735#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1736#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1737#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1738#define SQLITE_CONFIG_URI 17 /* int */ 1739#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1740#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1741#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1742#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1743#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1744#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1745 1746/* 1747** CAPI3REF: Database Connection Configuration Options 1748** 1749** These constants are the available integer configuration options that 1750** can be passed as the second argument to the [sqlite3_db_config()] interface. 1751** 1752** New configuration options may be added in future releases of SQLite. 1753** Existing configuration options might be discontinued. Applications 1754** should check the return code from [sqlite3_db_config()] to make sure that 1755** the call worked. ^The [sqlite3_db_config()] interface will return a 1756** non-zero [error code] if a discontinued or unsupported configuration option 1757** is invoked. 1758** 1759** <dl> 1760** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1761** <dd> ^This option takes three additional arguments that determine the 1762** [lookaside memory allocator] configuration for the [database connection]. 1763** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1764** pointer to a memory buffer to use for lookaside memory. 1765** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1766** may be NULL in which case SQLite will allocate the 1767** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1768** size of each lookaside buffer slot. ^The third argument is the number of 1769** slots. The size of the buffer in the first argument must be greater than 1770** or equal to the product of the second and third arguments. The buffer 1771** must be aligned to an 8-byte boundary. ^If the second argument to 1772** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1773** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1774** configuration for a database connection can only be changed when that 1775** connection is not currently using lookaside memory, or in other words 1776** when the "current value" returned by 1777** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1778** Any attempt to change the lookaside memory configuration when lookaside 1779** memory is in use leaves the configuration unchanged and returns 1780** [SQLITE_BUSY].)^</dd> 1781** 1782** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1783** <dd> ^This option is used to enable or disable the enforcement of 1784** [foreign key constraints]. There should be two additional arguments. 1785** The first argument is an integer which is 0 to disable FK enforcement, 1786** positive to enable FK enforcement or negative to leave FK enforcement 1787** unchanged. The second parameter is a pointer to an integer into which 1788** is written 0 or 1 to indicate whether FK enforcement is off or on 1789** following this call. The second parameter may be a NULL pointer, in 1790** which case the FK enforcement setting is not reported back. </dd> 1791** 1792** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1793** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1794** There should be two additional arguments. 1795** The first argument is an integer which is 0 to disable triggers, 1796** positive to enable triggers or negative to leave the setting unchanged. 1797** The second parameter is a pointer to an integer into which 1798** is written 0 or 1 to indicate whether triggers are disabled or enabled 1799** following this call. The second parameter may be a NULL pointer, in 1800** which case the trigger setting is not reported back. </dd> 1801** 1802** </dl> 1803*/ 1804#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1805#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1806#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1807 1808 1809/* 1810** CAPI3REF: Enable Or Disable Extended Result Codes 1811** 1812** ^The sqlite3_extended_result_codes() routine enables or disables the 1813** [extended result codes] feature of SQLite. ^The extended result 1814** codes are disabled by default for historical compatibility. 1815*/ 1816int sqlite3_extended_result_codes(sqlite3*, int onoff); 1817 1818/* 1819** CAPI3REF: Last Insert Rowid 1820** 1821** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1822** has a unique 64-bit signed 1823** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1824** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1825** names are not also used by explicitly declared columns. ^If 1826** the table has a column of type [INTEGER PRIMARY KEY] then that column 1827** is another alias for the rowid. 1828** 1829** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1830** most recent successful [INSERT] into a rowid table or [virtual table] 1831** on database connection D. 1832** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1833** ^If no successful [INSERT]s into rowid tables 1834** have ever occurred on the database connection D, 1835** then sqlite3_last_insert_rowid(D) returns zero. 1836** 1837** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1838** method, then this routine will return the [rowid] of the inserted 1839** row as long as the trigger or virtual table method is running. 1840** But once the trigger or virtual table method ends, the value returned 1841** by this routine reverts to what it was before the trigger or virtual 1842** table method began.)^ 1843** 1844** ^An [INSERT] that fails due to a constraint violation is not a 1845** successful [INSERT] and does not change the value returned by this 1846** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1847** and INSERT OR ABORT make no changes to the return value of this 1848** routine when their insertion fails. ^(When INSERT OR REPLACE 1849** encounters a constraint violation, it does not fail. The 1850** INSERT continues to completion after deleting rows that caused 1851** the constraint problem so INSERT OR REPLACE will always change 1852** the return value of this interface.)^ 1853** 1854** ^For the purposes of this routine, an [INSERT] is considered to 1855** be successful even if it is subsequently rolled back. 1856** 1857** This function is accessible to SQL statements via the 1858** [last_insert_rowid() SQL function]. 1859** 1860** If a separate thread performs a new [INSERT] on the same 1861** database connection while the [sqlite3_last_insert_rowid()] 1862** function is running and thus changes the last insert [rowid], 1863** then the value returned by [sqlite3_last_insert_rowid()] is 1864** unpredictable and might not equal either the old or the new 1865** last insert [rowid]. 1866*/ 1867sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1868 1869/* 1870** CAPI3REF: Count The Number Of Rows Modified 1871** 1872** ^This function returns the number of database rows that were changed 1873** or inserted or deleted by the most recently completed SQL statement 1874** on the [database connection] specified by the first parameter. 1875** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1876** or [DELETE] statement are counted. Auxiliary changes caused by 1877** triggers or [foreign key actions] are not counted.)^ Use the 1878** [sqlite3_total_changes()] function to find the total number of changes 1879** including changes caused by triggers and foreign key actions. 1880** 1881** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1882** are not counted. Only real table changes are counted. 1883** 1884** ^(A "row change" is a change to a single row of a single table 1885** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1886** are changed as side effects of [REPLACE] constraint resolution, 1887** rollback, ABORT processing, [DROP TABLE], or by any other 1888** mechanisms do not count as direct row changes.)^ 1889** 1890** A "trigger context" is a scope of execution that begins and 1891** ends with the script of a [CREATE TRIGGER | trigger]. 1892** Most SQL statements are 1893** evaluated outside of any trigger. This is the "top level" 1894** trigger context. If a trigger fires from the top level, a 1895** new trigger context is entered for the duration of that one 1896** trigger. Subtriggers create subcontexts for their duration. 1897** 1898** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1899** not create a new trigger context. 1900** 1901** ^This function returns the number of direct row changes in the 1902** most recent INSERT, UPDATE, or DELETE statement within the same 1903** trigger context. 1904** 1905** ^Thus, when called from the top level, this function returns the 1906** number of changes in the most recent INSERT, UPDATE, or DELETE 1907** that also occurred at the top level. ^(Within the body of a trigger, 1908** the sqlite3_changes() interface can be called to find the number of 1909** changes in the most recently completed INSERT, UPDATE, or DELETE 1910** statement within the body of the same trigger. 1911** However, the number returned does not include changes 1912** caused by subtriggers since those have their own context.)^ 1913** 1914** See also the [sqlite3_total_changes()] interface, the 1915** [count_changes pragma], and the [changes() SQL function]. 1916** 1917** If a separate thread makes changes on the same database connection 1918** while [sqlite3_changes()] is running then the value returned 1919** is unpredictable and not meaningful. 1920*/ 1921int sqlite3_changes(sqlite3*); 1922 1923/* 1924** CAPI3REF: Total Number Of Rows Modified 1925** 1926** ^This function returns the number of row changes caused by [INSERT], 1927** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1928** ^(The count returned by sqlite3_total_changes() includes all changes 1929** from all [CREATE TRIGGER | trigger] contexts and changes made by 1930** [foreign key actions]. However, 1931** the count does not include changes used to implement [REPLACE] constraints, 1932** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1933** count does not include rows of views that fire an [INSTEAD OF trigger], 1934** though if the INSTEAD OF trigger makes changes of its own, those changes 1935** are counted.)^ 1936** ^The sqlite3_total_changes() function counts the changes as soon as 1937** the statement that makes them is completed (when the statement handle 1938** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1939** 1940** See also the [sqlite3_changes()] interface, the 1941** [count_changes pragma], and the [total_changes() SQL function]. 1942** 1943** If a separate thread makes changes on the same database connection 1944** while [sqlite3_total_changes()] is running then the value 1945** returned is unpredictable and not meaningful. 1946*/ 1947int sqlite3_total_changes(sqlite3*); 1948 1949/* 1950** CAPI3REF: Interrupt A Long-Running Query 1951** 1952** ^This function causes any pending database operation to abort and 1953** return at its earliest opportunity. This routine is typically 1954** called in response to a user action such as pressing "Cancel" 1955** or Ctrl-C where the user wants a long query operation to halt 1956** immediately. 1957** 1958** ^It is safe to call this routine from a thread different from the 1959** thread that is currently running the database operation. But it 1960** is not safe to call this routine with a [database connection] that 1961** is closed or might close before sqlite3_interrupt() returns. 1962** 1963** ^If an SQL operation is very nearly finished at the time when 1964** sqlite3_interrupt() is called, then it might not have an opportunity 1965** to be interrupted and might continue to completion. 1966** 1967** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1968** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1969** that is inside an explicit transaction, then the entire transaction 1970** will be rolled back automatically. 1971** 1972** ^The sqlite3_interrupt(D) call is in effect until all currently running 1973** SQL statements on [database connection] D complete. ^Any new SQL statements 1974** that are started after the sqlite3_interrupt() call and before the 1975** running statements reaches zero are interrupted as if they had been 1976** running prior to the sqlite3_interrupt() call. ^New SQL statements 1977** that are started after the running statement count reaches zero are 1978** not effected by the sqlite3_interrupt(). 1979** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1980** SQL statements is a no-op and has no effect on SQL statements 1981** that are started after the sqlite3_interrupt() call returns. 1982** 1983** If the database connection closes while [sqlite3_interrupt()] 1984** is running then bad things will likely happen. 1985*/ 1986void sqlite3_interrupt(sqlite3*); 1987 1988/* 1989** CAPI3REF: Determine If An SQL Statement Is Complete 1990** 1991** These routines are useful during command-line input to determine if the 1992** currently entered text seems to form a complete SQL statement or 1993** if additional input is needed before sending the text into 1994** SQLite for parsing. ^These routines return 1 if the input string 1995** appears to be a complete SQL statement. ^A statement is judged to be 1996** complete if it ends with a semicolon token and is not a prefix of a 1997** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1998** string literals or quoted identifier names or comments are not 1999** independent tokens (they are part of the token in which they are 2000** embedded) and thus do not count as a statement terminator. ^Whitespace 2001** and comments that follow the final semicolon are ignored. 2002** 2003** ^These routines return 0 if the statement is incomplete. ^If a 2004** memory allocation fails, then SQLITE_NOMEM is returned. 2005** 2006** ^These routines do not parse the SQL statements thus 2007** will not detect syntactically incorrect SQL. 2008** 2009** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2010** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2011** automatically by sqlite3_complete16(). If that initialization fails, 2012** then the return value from sqlite3_complete16() will be non-zero 2013** regardless of whether or not the input SQL is complete.)^ 2014** 2015** The input to [sqlite3_complete()] must be a zero-terminated 2016** UTF-8 string. 2017** 2018** The input to [sqlite3_complete16()] must be a zero-terminated 2019** UTF-16 string in native byte order. 2020*/ 2021int sqlite3_complete(const char *sql); 2022int sqlite3_complete16(const void *sql); 2023 2024/* 2025** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2026** 2027** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2028** that might be invoked with argument P whenever 2029** an attempt is made to access a database table associated with 2030** [database connection] D when another thread 2031** or process has the table locked. 2032** The sqlite3_busy_handler() interface is used to implement 2033** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2034** 2035** ^If the busy callback is NULL, then [SQLITE_BUSY] 2036** is returned immediately upon encountering the lock. ^If the busy callback 2037** is not NULL, then the callback might be invoked with two arguments. 2038** 2039** ^The first argument to the busy handler is a copy of the void* pointer which 2040** is the third argument to sqlite3_busy_handler(). ^The second argument to 2041** the busy handler callback is the number of times that the busy handler has 2042** been invoked for the same locking event. ^If the 2043** busy callback returns 0, then no additional attempts are made to 2044** access the database and [SQLITE_BUSY] is returned 2045** to the application. 2046** ^If the callback returns non-zero, then another attempt 2047** is made to access the database and the cycle repeats. 2048** 2049** The presence of a busy handler does not guarantee that it will be invoked 2050** when there is lock contention. ^If SQLite determines that invoking the busy 2051** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2052** to the application instead of invoking the 2053** busy handler. 2054** Consider a scenario where one process is holding a read lock that 2055** it is trying to promote to a reserved lock and 2056** a second process is holding a reserved lock that it is trying 2057** to promote to an exclusive lock. The first process cannot proceed 2058** because it is blocked by the second and the second process cannot 2059** proceed because it is blocked by the first. If both processes 2060** invoke the busy handlers, neither will make any progress. Therefore, 2061** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2062** will induce the first process to release its read lock and allow 2063** the second process to proceed. 2064** 2065** ^The default busy callback is NULL. 2066** 2067** ^(There can only be a single busy handler defined for each 2068** [database connection]. Setting a new busy handler clears any 2069** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2070** or evaluating [PRAGMA busy_timeout=N] will change the 2071** busy handler and thus clear any previously set busy handler. 2072** 2073** The busy callback should not take any actions which modify the 2074** database connection that invoked the busy handler. In other words, 2075** the busy handler is not reentrant. Any such actions 2076** result in undefined behavior. 2077** 2078** A busy handler must not close the database connection 2079** or [prepared statement] that invoked the busy handler. 2080*/ 2081int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2082 2083/* 2084** CAPI3REF: Set A Busy Timeout 2085** 2086** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2087** for a specified amount of time when a table is locked. ^The handler 2088** will sleep multiple times until at least "ms" milliseconds of sleeping 2089** have accumulated. ^After at least "ms" milliseconds of sleeping, 2090** the handler returns 0 which causes [sqlite3_step()] to return 2091** [SQLITE_BUSY]. 2092** 2093** ^Calling this routine with an argument less than or equal to zero 2094** turns off all busy handlers. 2095** 2096** ^(There can only be a single busy handler for a particular 2097** [database connection] at any given moment. If another busy handler 2098** was defined (using [sqlite3_busy_handler()]) prior to calling 2099** this routine, that other busy handler is cleared.)^ 2100** 2101** See also: [PRAGMA busy_timeout] 2102*/ 2103int sqlite3_busy_timeout(sqlite3*, int ms); 2104 2105/* 2106** CAPI3REF: Convenience Routines For Running Queries 2107** 2108** This is a legacy interface that is preserved for backwards compatibility. 2109** Use of this interface is not recommended. 2110** 2111** Definition: A <b>result table</b> is memory data structure created by the 2112** [sqlite3_get_table()] interface. A result table records the 2113** complete query results from one or more queries. 2114** 2115** The table conceptually has a number of rows and columns. But 2116** these numbers are not part of the result table itself. These 2117** numbers are obtained separately. Let N be the number of rows 2118** and M be the number of columns. 2119** 2120** A result table is an array of pointers to zero-terminated UTF-8 strings. 2121** There are (N+1)*M elements in the array. The first M pointers point 2122** to zero-terminated strings that contain the names of the columns. 2123** The remaining entries all point to query results. NULL values result 2124** in NULL pointers. All other values are in their UTF-8 zero-terminated 2125** string representation as returned by [sqlite3_column_text()]. 2126** 2127** A result table might consist of one or more memory allocations. 2128** It is not safe to pass a result table directly to [sqlite3_free()]. 2129** A result table should be deallocated using [sqlite3_free_table()]. 2130** 2131** ^(As an example of the result table format, suppose a query result 2132** is as follows: 2133** 2134** <blockquote><pre> 2135** Name | Age 2136** ----------------------- 2137** Alice | 43 2138** Bob | 28 2139** Cindy | 21 2140** </pre></blockquote> 2141** 2142** There are two column (M==2) and three rows (N==3). Thus the 2143** result table has 8 entries. Suppose the result table is stored 2144** in an array names azResult. Then azResult holds this content: 2145** 2146** <blockquote><pre> 2147** azResult[0] = "Name"; 2148** azResult[1] = "Age"; 2149** azResult[2] = "Alice"; 2150** azResult[3] = "43"; 2151** azResult[4] = "Bob"; 2152** azResult[5] = "28"; 2153** azResult[6] = "Cindy"; 2154** azResult[7] = "21"; 2155** </pre></blockquote>)^ 2156** 2157** ^The sqlite3_get_table() function evaluates one or more 2158** semicolon-separated SQL statements in the zero-terminated UTF-8 2159** string of its 2nd parameter and returns a result table to the 2160** pointer given in its 3rd parameter. 2161** 2162** After the application has finished with the result from sqlite3_get_table(), 2163** it must pass the result table pointer to sqlite3_free_table() in order to 2164** release the memory that was malloced. Because of the way the 2165** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2166** function must not try to call [sqlite3_free()] directly. Only 2167** [sqlite3_free_table()] is able to release the memory properly and safely. 2168** 2169** The sqlite3_get_table() interface is implemented as a wrapper around 2170** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2171** to any internal data structures of SQLite. It uses only the public 2172** interface defined here. As a consequence, errors that occur in the 2173** wrapper layer outside of the internal [sqlite3_exec()] call are not 2174** reflected in subsequent calls to [sqlite3_errcode()] or 2175** [sqlite3_errmsg()]. 2176*/ 2177int sqlite3_get_table( 2178 sqlite3 *db, /* An open database */ 2179 const char *zSql, /* SQL to be evaluated */ 2180 char ***pazResult, /* Results of the query */ 2181 int *pnRow, /* Number of result rows written here */ 2182 int *pnColumn, /* Number of result columns written here */ 2183 char **pzErrmsg /* Error msg written here */ 2184); 2185void sqlite3_free_table(char **result); 2186 2187/* 2188** CAPI3REF: Formatted String Printing Functions 2189** 2190** These routines are work-alikes of the "printf()" family of functions 2191** from the standard C library. 2192** 2193** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2194** results into memory obtained from [sqlite3_malloc()]. 2195** The strings returned by these two routines should be 2196** released by [sqlite3_free()]. ^Both routines return a 2197** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2198** memory to hold the resulting string. 2199** 2200** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2201** the standard C library. The result is written into the 2202** buffer supplied as the second parameter whose size is given by 2203** the first parameter. Note that the order of the 2204** first two parameters is reversed from snprintf().)^ This is an 2205** historical accident that cannot be fixed without breaking 2206** backwards compatibility. ^(Note also that sqlite3_snprintf() 2207** returns a pointer to its buffer instead of the number of 2208** characters actually written into the buffer.)^ We admit that 2209** the number of characters written would be a more useful return 2210** value but we cannot change the implementation of sqlite3_snprintf() 2211** now without breaking compatibility. 2212** 2213** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2214** guarantees that the buffer is always zero-terminated. ^The first 2215** parameter "n" is the total size of the buffer, including space for 2216** the zero terminator. So the longest string that can be completely 2217** written will be n-1 characters. 2218** 2219** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2220** 2221** These routines all implement some additional formatting 2222** options that are useful for constructing SQL statements. 2223** All of the usual printf() formatting options apply. In addition, there 2224** is are "%q", "%Q", and "%z" options. 2225** 2226** ^(The %q option works like %s in that it substitutes a nul-terminated 2227** string from the argument list. But %q also doubles every '\'' character. 2228** %q is designed for use inside a string literal.)^ By doubling each '\'' 2229** character it escapes that character and allows it to be inserted into 2230** the string. 2231** 2232** For example, assume the string variable zText contains text as follows: 2233** 2234** <blockquote><pre> 2235** char *zText = "It's a happy day!"; 2236** </pre></blockquote> 2237** 2238** One can use this text in an SQL statement as follows: 2239** 2240** <blockquote><pre> 2241** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2242** sqlite3_exec(db, zSQL, 0, 0, 0); 2243** sqlite3_free(zSQL); 2244** </pre></blockquote> 2245** 2246** Because the %q format string is used, the '\'' character in zText 2247** is escaped and the SQL generated is as follows: 2248** 2249** <blockquote><pre> 2250** INSERT INTO table1 VALUES('It''s a happy day!') 2251** </pre></blockquote> 2252** 2253** This is correct. Had we used %s instead of %q, the generated SQL 2254** would have looked like this: 2255** 2256** <blockquote><pre> 2257** INSERT INTO table1 VALUES('It's a happy day!'); 2258** </pre></blockquote> 2259** 2260** This second example is an SQL syntax error. As a general rule you should 2261** always use %q instead of %s when inserting text into a string literal. 2262** 2263** ^(The %Q option works like %q except it also adds single quotes around 2264** the outside of the total string. Additionally, if the parameter in the 2265** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2266** single quotes).)^ So, for example, one could say: 2267** 2268** <blockquote><pre> 2269** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2270** sqlite3_exec(db, zSQL, 0, 0, 0); 2271** sqlite3_free(zSQL); 2272** </pre></blockquote> 2273** 2274** The code above will render a correct SQL statement in the zSQL 2275** variable even if the zText variable is a NULL pointer. 2276** 2277** ^(The "%z" formatting option works like "%s" but with the 2278** addition that after the string has been read and copied into 2279** the result, [sqlite3_free()] is called on the input string.)^ 2280*/ 2281char *sqlite3_mprintf(const char*,...); 2282char *sqlite3_vmprintf(const char*, va_list); 2283char *sqlite3_snprintf(int,char*,const char*, ...); 2284char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2285 2286/* 2287** CAPI3REF: Memory Allocation Subsystem 2288** 2289** The SQLite core uses these three routines for all of its own 2290** internal memory allocation needs. "Core" in the previous sentence 2291** does not include operating-system specific VFS implementation. The 2292** Windows VFS uses native malloc() and free() for some operations. 2293** 2294** ^The sqlite3_malloc() routine returns a pointer to a block 2295** of memory at least N bytes in length, where N is the parameter. 2296** ^If sqlite3_malloc() is unable to obtain sufficient free 2297** memory, it returns a NULL pointer. ^If the parameter N to 2298** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2299** a NULL pointer. 2300** 2301** ^Calling sqlite3_free() with a pointer previously returned 2302** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2303** that it might be reused. ^The sqlite3_free() routine is 2304** a no-op if is called with a NULL pointer. Passing a NULL pointer 2305** to sqlite3_free() is harmless. After being freed, memory 2306** should neither be read nor written. Even reading previously freed 2307** memory might result in a segmentation fault or other severe error. 2308** Memory corruption, a segmentation fault, or other severe error 2309** might result if sqlite3_free() is called with a non-NULL pointer that 2310** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2311** 2312** ^(The sqlite3_realloc() interface attempts to resize a 2313** prior memory allocation to be at least N bytes, where N is the 2314** second parameter. The memory allocation to be resized is the first 2315** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2316** is a NULL pointer then its behavior is identical to calling 2317** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2318** ^If the second parameter to sqlite3_realloc() is zero or 2319** negative then the behavior is exactly the same as calling 2320** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2321** ^sqlite3_realloc() returns a pointer to a memory allocation 2322** of at least N bytes in size or NULL if sufficient memory is unavailable. 2323** ^If M is the size of the prior allocation, then min(N,M) bytes 2324** of the prior allocation are copied into the beginning of buffer returned 2325** by sqlite3_realloc() and the prior allocation is freed. 2326** ^If sqlite3_realloc() returns NULL, then the prior allocation 2327** is not freed. 2328** 2329** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2330** is always aligned to at least an 8 byte boundary, or to a 2331** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2332** option is used. 2333** 2334** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2335** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2336** implementation of these routines to be omitted. That capability 2337** is no longer provided. Only built-in memory allocators can be used. 2338** 2339** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2340** the system malloc() and free() directly when converting 2341** filenames between the UTF-8 encoding used by SQLite 2342** and whatever filename encoding is used by the particular Windows 2343** installation. Memory allocation errors were detected, but 2344** they were reported back as [SQLITE_CANTOPEN] or 2345** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2346** 2347** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2348** must be either NULL or else pointers obtained from a prior 2349** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2350** not yet been released. 2351** 2352** The application must not read or write any part of 2353** a block of memory after it has been released using 2354** [sqlite3_free()] or [sqlite3_realloc()]. 2355*/ 2356void *sqlite3_malloc(int); 2357void *sqlite3_realloc(void*, int); 2358void sqlite3_free(void*); 2359 2360/* 2361** CAPI3REF: Memory Allocator Statistics 2362** 2363** SQLite provides these two interfaces for reporting on the status 2364** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2365** routines, which form the built-in memory allocation subsystem. 2366** 2367** ^The [sqlite3_memory_used()] routine returns the number of bytes 2368** of memory currently outstanding (malloced but not freed). 2369** ^The [sqlite3_memory_highwater()] routine returns the maximum 2370** value of [sqlite3_memory_used()] since the high-water mark 2371** was last reset. ^The values returned by [sqlite3_memory_used()] and 2372** [sqlite3_memory_highwater()] include any overhead 2373** added by SQLite in its implementation of [sqlite3_malloc()], 2374** but not overhead added by the any underlying system library 2375** routines that [sqlite3_malloc()] may call. 2376** 2377** ^The memory high-water mark is reset to the current value of 2378** [sqlite3_memory_used()] if and only if the parameter to 2379** [sqlite3_memory_highwater()] is true. ^The value returned 2380** by [sqlite3_memory_highwater(1)] is the high-water mark 2381** prior to the reset. 2382*/ 2383sqlite3_int64 sqlite3_memory_used(void); 2384sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2385 2386/* 2387** CAPI3REF: Pseudo-Random Number Generator 2388** 2389** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2390** select random [ROWID | ROWIDs] when inserting new records into a table that 2391** already uses the largest possible [ROWID]. The PRNG is also used for 2392** the build-in random() and randomblob() SQL functions. This interface allows 2393** applications to access the same PRNG for other purposes. 2394** 2395** ^A call to this routine stores N bytes of randomness into buffer P. 2396** ^If N is less than one, then P can be a NULL pointer. 2397** 2398** ^If this routine has not been previously called or if the previous 2399** call had N less than one, then the PRNG is seeded using randomness 2400** obtained from the xRandomness method of the default [sqlite3_vfs] object. 2401** ^If the previous call to this routine had an N of 1 or more then 2402** the pseudo-randomness is generated 2403** internally and without recourse to the [sqlite3_vfs] xRandomness 2404** method. 2405*/ 2406void sqlite3_randomness(int N, void *P); 2407 2408/* 2409** CAPI3REF: Compile-Time Authorization Callbacks 2410** 2411** ^This routine registers an authorizer callback with a particular 2412** [database connection], supplied in the first argument. 2413** ^The authorizer callback is invoked as SQL statements are being compiled 2414** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2415** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2416** points during the compilation process, as logic is being created 2417** to perform various actions, the authorizer callback is invoked to 2418** see if those actions are allowed. ^The authorizer callback should 2419** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2420** specific action but allow the SQL statement to continue to be 2421** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2422** rejected with an error. ^If the authorizer callback returns 2423** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2424** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2425** the authorizer will fail with an error message. 2426** 2427** When the callback returns [SQLITE_OK], that means the operation 2428** requested is ok. ^When the callback returns [SQLITE_DENY], the 2429** [sqlite3_prepare_v2()] or equivalent call that triggered the 2430** authorizer will fail with an error message explaining that 2431** access is denied. 2432** 2433** ^The first parameter to the authorizer callback is a copy of the third 2434** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2435** to the callback is an integer [SQLITE_COPY | action code] that specifies 2436** the particular action to be authorized. ^The third through sixth parameters 2437** to the callback are zero-terminated strings that contain additional 2438** details about the action to be authorized. 2439** 2440** ^If the action code is [SQLITE_READ] 2441** and the callback returns [SQLITE_IGNORE] then the 2442** [prepared statement] statement is constructed to substitute 2443** a NULL value in place of the table column that would have 2444** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2445** return can be used to deny an untrusted user access to individual 2446** columns of a table. 2447** ^If the action code is [SQLITE_DELETE] and the callback returns 2448** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2449** [truncate optimization] is disabled and all rows are deleted individually. 2450** 2451** An authorizer is used when [sqlite3_prepare | preparing] 2452** SQL statements from an untrusted source, to ensure that the SQL statements 2453** do not try to access data they are not allowed to see, or that they do not 2454** try to execute malicious statements that damage the database. For 2455** example, an application may allow a user to enter arbitrary 2456** SQL queries for evaluation by a database. But the application does 2457** not want the user to be able to make arbitrary changes to the 2458** database. An authorizer could then be put in place while the 2459** user-entered SQL is being [sqlite3_prepare | prepared] that 2460** disallows everything except [SELECT] statements. 2461** 2462** Applications that need to process SQL from untrusted sources 2463** might also consider lowering resource limits using [sqlite3_limit()] 2464** and limiting database size using the [max_page_count] [PRAGMA] 2465** in addition to using an authorizer. 2466** 2467** ^(Only a single authorizer can be in place on a database connection 2468** at a time. Each call to sqlite3_set_authorizer overrides the 2469** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2470** The authorizer is disabled by default. 2471** 2472** The authorizer callback must not do anything that will modify 2473** the database connection that invoked the authorizer callback. 2474** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2475** database connections for the meaning of "modify" in this paragraph. 2476** 2477** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2478** statement might be re-prepared during [sqlite3_step()] due to a 2479** schema change. Hence, the application should ensure that the 2480** correct authorizer callback remains in place during the [sqlite3_step()]. 2481** 2482** ^Note that the authorizer callback is invoked only during 2483** [sqlite3_prepare()] or its variants. Authorization is not 2484** performed during statement evaluation in [sqlite3_step()], unless 2485** as stated in the previous paragraph, sqlite3_step() invokes 2486** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2487*/ 2488int sqlite3_set_authorizer( 2489 sqlite3*, 2490 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2491 void *pUserData 2492); 2493 2494/* 2495** CAPI3REF: Authorizer Return Codes 2496** 2497** The [sqlite3_set_authorizer | authorizer callback function] must 2498** return either [SQLITE_OK] or one of these two constants in order 2499** to signal SQLite whether or not the action is permitted. See the 2500** [sqlite3_set_authorizer | authorizer documentation] for additional 2501** information. 2502** 2503** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2504** returned from the [sqlite3_vtab_on_conflict()] interface. 2505*/ 2506#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2507#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2508 2509/* 2510** CAPI3REF: Authorizer Action Codes 2511** 2512** The [sqlite3_set_authorizer()] interface registers a callback function 2513** that is invoked to authorize certain SQL statement actions. The 2514** second parameter to the callback is an integer code that specifies 2515** what action is being authorized. These are the integer action codes that 2516** the authorizer callback may be passed. 2517** 2518** These action code values signify what kind of operation is to be 2519** authorized. The 3rd and 4th parameters to the authorization 2520** callback function will be parameters or NULL depending on which of these 2521** codes is used as the second parameter. ^(The 5th parameter to the 2522** authorizer callback is the name of the database ("main", "temp", 2523** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2524** is the name of the inner-most trigger or view that is responsible for 2525** the access attempt or NULL if this access attempt is directly from 2526** top-level SQL code. 2527*/ 2528/******************************************* 3rd ************ 4th ***********/ 2529#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2530#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2531#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2532#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2533#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2534#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2535#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2536#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2537#define SQLITE_DELETE 9 /* Table Name NULL */ 2538#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2539#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2540#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2541#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2542#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2543#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2544#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2545#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2546#define SQLITE_INSERT 18 /* Table Name NULL */ 2547#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2548#define SQLITE_READ 20 /* Table Name Column Name */ 2549#define SQLITE_SELECT 21 /* NULL NULL */ 2550#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2551#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2552#define SQLITE_ATTACH 24 /* Filename NULL */ 2553#define SQLITE_DETACH 25 /* Database Name NULL */ 2554#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2555#define SQLITE_REINDEX 27 /* Index Name NULL */ 2556#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2557#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2558#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2559#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2560#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2561#define SQLITE_COPY 0 /* No longer used */ 2562#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2563 2564/* 2565** CAPI3REF: Tracing And Profiling Functions 2566** 2567** These routines register callback functions that can be used for 2568** tracing and profiling the execution of SQL statements. 2569** 2570** ^The callback function registered by sqlite3_trace() is invoked at 2571** various times when an SQL statement is being run by [sqlite3_step()]. 2572** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2573** SQL statement text as the statement first begins executing. 2574** ^(Additional sqlite3_trace() callbacks might occur 2575** as each triggered subprogram is entered. The callbacks for triggers 2576** contain a UTF-8 SQL comment that identifies the trigger.)^ 2577** 2578** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2579** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2580** 2581** ^The callback function registered by sqlite3_profile() is invoked 2582** as each SQL statement finishes. ^The profile callback contains 2583** the original statement text and an estimate of wall-clock time 2584** of how long that statement took to run. ^The profile callback 2585** time is in units of nanoseconds, however the current implementation 2586** is only capable of millisecond resolution so the six least significant 2587** digits in the time are meaningless. Future versions of SQLite 2588** might provide greater resolution on the profiler callback. The 2589** sqlite3_profile() function is considered experimental and is 2590** subject to change in future versions of SQLite. 2591*/ 2592void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2593SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2594 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2595 2596/* 2597** CAPI3REF: Query Progress Callbacks 2598** 2599** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2600** function X to be invoked periodically during long running calls to 2601** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2602** database connection D. An example use for this 2603** interface is to keep a GUI updated during a large query. 2604** 2605** ^The parameter P is passed through as the only parameter to the 2606** callback function X. ^The parameter N is the approximate number of 2607** [virtual machine instructions] that are evaluated between successive 2608** invocations of the callback X. ^If N is less than one then the progress 2609** handler is disabled. 2610** 2611** ^Only a single progress handler may be defined at one time per 2612** [database connection]; setting a new progress handler cancels the 2613** old one. ^Setting parameter X to NULL disables the progress handler. 2614** ^The progress handler is also disabled by setting N to a value less 2615** than 1. 2616** 2617** ^If the progress callback returns non-zero, the operation is 2618** interrupted. This feature can be used to implement a 2619** "Cancel" button on a GUI progress dialog box. 2620** 2621** The progress handler callback must not do anything that will modify 2622** the database connection that invoked the progress handler. 2623** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2624** database connections for the meaning of "modify" in this paragraph. 2625** 2626*/ 2627void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2628 2629/* 2630** CAPI3REF: Opening A New Database Connection 2631** 2632** ^These routines open an SQLite database file as specified by the 2633** filename argument. ^The filename argument is interpreted as UTF-8 for 2634** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2635** order for sqlite3_open16(). ^(A [database connection] handle is usually 2636** returned in *ppDb, even if an error occurs. The only exception is that 2637** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2638** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2639** object.)^ ^(If the database is opened (and/or created) successfully, then 2640** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2641** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2642** an English language description of the error following a failure of any 2643** of the sqlite3_open() routines. 2644** 2645** ^The default encoding for the database will be UTF-8 if 2646** sqlite3_open() or sqlite3_open_v2() is called and 2647** UTF-16 in the native byte order if sqlite3_open16() is used. 2648** 2649** Whether or not an error occurs when it is opened, resources 2650** associated with the [database connection] handle should be released by 2651** passing it to [sqlite3_close()] when it is no longer required. 2652** 2653** The sqlite3_open_v2() interface works like sqlite3_open() 2654** except that it accepts two additional parameters for additional control 2655** over the new database connection. ^(The flags parameter to 2656** sqlite3_open_v2() can take one of 2657** the following three values, optionally combined with the 2658** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2659** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2660** 2661** <dl> 2662** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2663** <dd>The database is opened in read-only mode. If the database does not 2664** already exist, an error is returned.</dd>)^ 2665** 2666** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2667** <dd>The database is opened for reading and writing if possible, or reading 2668** only if the file is write protected by the operating system. In either 2669** case the database must already exist, otherwise an error is returned.</dd>)^ 2670** 2671** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2672** <dd>The database is opened for reading and writing, and is created if 2673** it does not already exist. This is the behavior that is always used for 2674** sqlite3_open() and sqlite3_open16().</dd>)^ 2675** </dl> 2676** 2677** If the 3rd parameter to sqlite3_open_v2() is not one of the 2678** combinations shown above optionally combined with other 2679** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2680** then the behavior is undefined. 2681** 2682** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2683** opens in the multi-thread [threading mode] as long as the single-thread 2684** mode has not been set at compile-time or start-time. ^If the 2685** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2686** in the serialized [threading mode] unless single-thread was 2687** previously selected at compile-time or start-time. 2688** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2689** eligible to use [shared cache mode], regardless of whether or not shared 2690** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2691** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2692** participate in [shared cache mode] even if it is enabled. 2693** 2694** ^The fourth parameter to sqlite3_open_v2() is the name of the 2695** [sqlite3_vfs] object that defines the operating system interface that 2696** the new database connection should use. ^If the fourth parameter is 2697** a NULL pointer then the default [sqlite3_vfs] object is used. 2698** 2699** ^If the filename is ":memory:", then a private, temporary in-memory database 2700** is created for the connection. ^This in-memory database will vanish when 2701** the database connection is closed. Future versions of SQLite might 2702** make use of additional special filenames that begin with the ":" character. 2703** It is recommended that when a database filename actually does begin with 2704** a ":" character you should prefix the filename with a pathname such as 2705** "./" to avoid ambiguity. 2706** 2707** ^If the filename is an empty string, then a private, temporary 2708** on-disk database will be created. ^This private database will be 2709** automatically deleted as soon as the database connection is closed. 2710** 2711** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2712** 2713** ^If [URI filename] interpretation is enabled, and the filename argument 2714** begins with "file:", then the filename is interpreted as a URI. ^URI 2715** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2716** set in the fourth argument to sqlite3_open_v2(), or if it has 2717** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2718** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2719** As of SQLite version 3.7.7, URI filename interpretation is turned off 2720** by default, but future releases of SQLite might enable URI filename 2721** interpretation by default. See "[URI filenames]" for additional 2722** information. 2723** 2724** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2725** authority, then it must be either an empty string or the string 2726** "localhost". ^If the authority is not an empty string or "localhost", an 2727** error is returned to the caller. ^The fragment component of a URI, if 2728** present, is ignored. 2729** 2730** ^SQLite uses the path component of the URI as the name of the disk file 2731** which contains the database. ^If the path begins with a '/' character, 2732** then it is interpreted as an absolute path. ^If the path does not begin 2733** with a '/' (meaning that the authority section is omitted from the URI) 2734** then the path is interpreted as a relative path. 2735** ^On windows, the first component of an absolute path 2736** is a drive specification (e.g. "C:"). 2737** 2738** [[core URI query parameters]] 2739** The query component of a URI may contain parameters that are interpreted 2740** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2741** SQLite interprets the following three query parameters: 2742** 2743** <ul> 2744** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2745** a VFS object that provides the operating system interface that should 2746** be used to access the database file on disk. ^If this option is set to 2747** an empty string the default VFS object is used. ^Specifying an unknown 2748** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2749** present, then the VFS specified by the option takes precedence over 2750** the value passed as the fourth parameter to sqlite3_open_v2(). 2751** 2752** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2753** "rwc", or "memory". Attempting to set it to any other value is 2754** an error)^. 2755** ^If "ro" is specified, then the database is opened for read-only 2756** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2757** third argument to sqlite3_open_v2(). ^If the mode option is set to 2758** "rw", then the database is opened for read-write (but not create) 2759** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2760** been set. ^Value "rwc" is equivalent to setting both 2761** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2762** set to "memory" then a pure [in-memory database] that never reads 2763** or writes from disk is used. ^It is an error to specify a value for 2764** the mode parameter that is less restrictive than that specified by 2765** the flags passed in the third parameter to sqlite3_open_v2(). 2766** 2767** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2768** "private". ^Setting it to "shared" is equivalent to setting the 2769** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2770** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2771** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2772** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2773** a URI filename, its value overrides any behavior requested by setting 2774** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2775** 2776** <li> <b>psow</b>: ^The psow parameter may be "true" (or "on" or "yes" or 2777** "1") or "false" (or "off" or "no" or "0") to indicate that the 2778** [powersafe overwrite] property does or does not apply to the 2779** storage media on which the database file resides. ^The psow query 2780** parameter only works for the built-in unix and Windows VFSes. 2781** 2782** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2783** which if set disables file locking in rollback journal modes. This 2784** is useful for accessing a database on a filesystem that does not 2785** support locking. Caution: Database corruption might result if two 2786** or more processes write to the same database and any one of those 2787** processes uses nolock=1. 2788** 2789** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2790** parameter that indicates that the database file is stored on 2791** read-only media. ^When immutable is set, SQLite assumes that the 2792** database file cannot be changed, even by a process with higher 2793** privilege, and so the database is opened read-only and all locking 2794** and change detection is disabled. Caution: Setting the immutable 2795** property on a database file that does in fact change can result 2796** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2797** See also: [SQLITE_IOCAP_IMMUTABLE]. 2798** 2799** </ul> 2800** 2801** ^Specifying an unknown parameter in the query component of a URI is not an 2802** error. Future versions of SQLite might understand additional query 2803** parameters. See "[query parameters with special meaning to SQLite]" for 2804** additional information. 2805** 2806** [[URI filename examples]] <h3>URI filename examples</h3> 2807** 2808** <table border="1" align=center cellpadding=5> 2809** <tr><th> URI filenames <th> Results 2810** <tr><td> file:data.db <td> 2811** Open the file "data.db" in the current directory. 2812** <tr><td> file:/home/fred/data.db<br> 2813** file:///home/fred/data.db <br> 2814** file://localhost/home/fred/data.db <br> <td> 2815** Open the database file "/home/fred/data.db". 2816** <tr><td> file://darkstar/home/fred/data.db <td> 2817** An error. "darkstar" is not a recognized authority. 2818** <tr><td style="white-space:nowrap"> 2819** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2820** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2821** C:. Note that the %20 escaping in this example is not strictly 2822** necessary - space characters can be used literally 2823** in URI filenames. 2824** <tr><td> file:data.db?mode=ro&cache=private <td> 2825** Open file "data.db" in the current directory for read-only access. 2826** Regardless of whether or not shared-cache mode is enabled by 2827** default, use a private cache. 2828** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2829** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2830** that uses dot-files in place of posix advisory locking. 2831** <tr><td> file:data.db?mode=readonly <td> 2832** An error. "readonly" is not a valid option for the "mode" parameter. 2833** </table> 2834** 2835** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2836** query components of a URI. A hexadecimal escape sequence consists of a 2837** percent sign - "%" - followed by exactly two hexadecimal digits 2838** specifying an octet value. ^Before the path or query components of a 2839** URI filename are interpreted, they are encoded using UTF-8 and all 2840** hexadecimal escape sequences replaced by a single byte containing the 2841** corresponding octet. If this process generates an invalid UTF-8 encoding, 2842** the results are undefined. 2843** 2844** <b>Note to Windows users:</b> The encoding used for the filename argument 2845** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2846** codepage is currently defined. Filenames containing international 2847** characters must be converted to UTF-8 prior to passing them into 2848** sqlite3_open() or sqlite3_open_v2(). 2849** 2850** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2851** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2852** features that require the use of temporary files may fail. 2853** 2854** See also: [sqlite3_temp_directory] 2855*/ 2856int sqlite3_open( 2857 const char *filename, /* Database filename (UTF-8) */ 2858 sqlite3 **ppDb /* OUT: SQLite db handle */ 2859); 2860int sqlite3_open16( 2861 const void *filename, /* Database filename (UTF-16) */ 2862 sqlite3 **ppDb /* OUT: SQLite db handle */ 2863); 2864int sqlite3_open_v2( 2865 const char *filename, /* Database filename (UTF-8) */ 2866 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2867 int flags, /* Flags */ 2868 const char *zVfs /* Name of VFS module to use */ 2869); 2870 2871/* 2872** CAPI3REF: Obtain Values For URI Parameters 2873** 2874** These are utility routines, useful to VFS implementations, that check 2875** to see if a database file was a URI that contained a specific query 2876** parameter, and if so obtains the value of that query parameter. 2877** 2878** If F is the database filename pointer passed into the xOpen() method of 2879** a VFS implementation when the flags parameter to xOpen() has one or 2880** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2881** P is the name of the query parameter, then 2882** sqlite3_uri_parameter(F,P) returns the value of the P 2883** parameter if it exists or a NULL pointer if P does not appear as a 2884** query parameter on F. If P is a query parameter of F 2885** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2886** a pointer to an empty string. 2887** 2888** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2889** parameter and returns true (1) or false (0) according to the value 2890** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2891** value of query parameter P is one of "yes", "true", or "on" in any 2892** case or if the value begins with a non-zero number. The 2893** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2894** query parameter P is one of "no", "false", or "off" in any case or 2895** if the value begins with a numeric zero. If P is not a query 2896** parameter on F or if the value of P is does not match any of the 2897** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2898** 2899** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2900** 64-bit signed integer and returns that integer, or D if P does not 2901** exist. If the value of P is something other than an integer, then 2902** zero is returned. 2903** 2904** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2905** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2906** is not a database file pathname pointer that SQLite passed into the xOpen 2907** VFS method, then the behavior of this routine is undefined and probably 2908** undesirable. 2909*/ 2910const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2911int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2912sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2913 2914 2915/* 2916** CAPI3REF: Error Codes And Messages 2917** 2918** ^The sqlite3_errcode() interface returns the numeric [result code] or 2919** [extended result code] for the most recent failed sqlite3_* API call 2920** associated with a [database connection]. If a prior API call failed 2921** but the most recent API call succeeded, the return value from 2922** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2923** interface is the same except that it always returns the 2924** [extended result code] even when extended result codes are 2925** disabled. 2926** 2927** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2928** text that describes the error, as either UTF-8 or UTF-16 respectively. 2929** ^(Memory to hold the error message string is managed internally. 2930** The application does not need to worry about freeing the result. 2931** However, the error string might be overwritten or deallocated by 2932** subsequent calls to other SQLite interface functions.)^ 2933** 2934** ^The sqlite3_errstr() interface returns the English-language text 2935** that describes the [result code], as UTF-8. 2936** ^(Memory to hold the error message string is managed internally 2937** and must not be freed by the application)^. 2938** 2939** When the serialized [threading mode] is in use, it might be the 2940** case that a second error occurs on a separate thread in between 2941** the time of the first error and the call to these interfaces. 2942** When that happens, the second error will be reported since these 2943** interfaces always report the most recent result. To avoid 2944** this, each thread can obtain exclusive use of the [database connection] D 2945** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2946** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2947** all calls to the interfaces listed here are completed. 2948** 2949** If an interface fails with SQLITE_MISUSE, that means the interface 2950** was invoked incorrectly by the application. In that case, the 2951** error code and message may or may not be set. 2952*/ 2953int sqlite3_errcode(sqlite3 *db); 2954int sqlite3_extended_errcode(sqlite3 *db); 2955const char *sqlite3_errmsg(sqlite3*); 2956const void *sqlite3_errmsg16(sqlite3*); 2957const char *sqlite3_errstr(int); 2958 2959/* 2960** CAPI3REF: SQL Statement Object 2961** KEYWORDS: {prepared statement} {prepared statements} 2962** 2963** An instance of this object represents a single SQL statement. 2964** This object is variously known as a "prepared statement" or a 2965** "compiled SQL statement" or simply as a "statement". 2966** 2967** The life of a statement object goes something like this: 2968** 2969** <ol> 2970** <li> Create the object using [sqlite3_prepare_v2()] or a related 2971** function. 2972** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2973** interfaces. 2974** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2975** <li> Reset the statement using [sqlite3_reset()] then go back 2976** to step 2. Do this zero or more times. 2977** <li> Destroy the object using [sqlite3_finalize()]. 2978** </ol> 2979** 2980** Refer to documentation on individual methods above for additional 2981** information. 2982*/ 2983typedef struct sqlite3_stmt sqlite3_stmt; 2984 2985/* 2986** CAPI3REF: Run-time Limits 2987** 2988** ^(This interface allows the size of various constructs to be limited 2989** on a connection by connection basis. The first parameter is the 2990** [database connection] whose limit is to be set or queried. The 2991** second parameter is one of the [limit categories] that define a 2992** class of constructs to be size limited. The third parameter is the 2993** new limit for that construct.)^ 2994** 2995** ^If the new limit is a negative number, the limit is unchanged. 2996** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2997** [limits | hard upper bound] 2998** set at compile-time by a C preprocessor macro called 2999** [limits | SQLITE_MAX_<i>NAME</i>]. 3000** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3001** ^Attempts to increase a limit above its hard upper bound are 3002** silently truncated to the hard upper bound. 3003** 3004** ^Regardless of whether or not the limit was changed, the 3005** [sqlite3_limit()] interface returns the prior value of the limit. 3006** ^Hence, to find the current value of a limit without changing it, 3007** simply invoke this interface with the third parameter set to -1. 3008** 3009** Run-time limits are intended for use in applications that manage 3010** both their own internal database and also databases that are controlled 3011** by untrusted external sources. An example application might be a 3012** web browser that has its own databases for storing history and 3013** separate databases controlled by JavaScript applications downloaded 3014** off the Internet. The internal databases can be given the 3015** large, default limits. Databases managed by external sources can 3016** be given much smaller limits designed to prevent a denial of service 3017** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3018** interface to further control untrusted SQL. The size of the database 3019** created by an untrusted script can be contained using the 3020** [max_page_count] [PRAGMA]. 3021** 3022** New run-time limit categories may be added in future releases. 3023*/ 3024int sqlite3_limit(sqlite3*, int id, int newVal); 3025 3026/* 3027** CAPI3REF: Run-Time Limit Categories 3028** KEYWORDS: {limit category} {*limit categories} 3029** 3030** These constants define various performance limits 3031** that can be lowered at run-time using [sqlite3_limit()]. 3032** The synopsis of the meanings of the various limits is shown below. 3033** Additional information is available at [limits | Limits in SQLite]. 3034** 3035** <dl> 3036** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3037** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3038** 3039** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3040** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3041** 3042** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3043** <dd>The maximum number of columns in a table definition or in the 3044** result set of a [SELECT] or the maximum number of columns in an index 3045** or in an ORDER BY or GROUP BY clause.</dd>)^ 3046** 3047** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3048** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3049** 3050** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3051** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3052** 3053** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3054** <dd>The maximum number of instructions in a virtual machine program 3055** used to implement an SQL statement. This limit is not currently 3056** enforced, though that might be added in some future release of 3057** SQLite.</dd>)^ 3058** 3059** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3060** <dd>The maximum number of arguments on a function.</dd>)^ 3061** 3062** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3063** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3064** 3065** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3066** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3067** <dd>The maximum length of the pattern argument to the [LIKE] or 3068** [GLOB] operators.</dd>)^ 3069** 3070** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3071** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3072** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3073** 3074** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3075** <dd>The maximum depth of recursion for triggers.</dd>)^ 3076** 3077** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3078** <dd>The maximum number of auxiliary worker threads that a single 3079** [prepared statement] may start.</dd>)^ 3080** </dl> 3081*/ 3082#define SQLITE_LIMIT_LENGTH 0 3083#define SQLITE_LIMIT_SQL_LENGTH 1 3084#define SQLITE_LIMIT_COLUMN 2 3085#define SQLITE_LIMIT_EXPR_DEPTH 3 3086#define SQLITE_LIMIT_COMPOUND_SELECT 4 3087#define SQLITE_LIMIT_VDBE_OP 5 3088#define SQLITE_LIMIT_FUNCTION_ARG 6 3089#define SQLITE_LIMIT_ATTACHED 7 3090#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3091#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3092#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3093#define SQLITE_LIMIT_WORKER_THREADS 11 3094 3095/* 3096** CAPI3REF: Compiling An SQL Statement 3097** KEYWORDS: {SQL statement compiler} 3098** 3099** To execute an SQL query, it must first be compiled into a byte-code 3100** program using one of these routines. 3101** 3102** The first argument, "db", is a [database connection] obtained from a 3103** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3104** [sqlite3_open16()]. The database connection must not have been closed. 3105** 3106** The second argument, "zSql", is the statement to be compiled, encoded 3107** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3108** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3109** use UTF-16. 3110** 3111** ^If the nByte argument is less than zero, then zSql is read up to the 3112** first zero terminator. ^If nByte is non-negative, then it is the maximum 3113** number of bytes read from zSql. ^When nByte is non-negative, the 3114** zSql string ends at either the first '\000' or '\u0000' character or 3115** the nByte-th byte, whichever comes first. If the caller knows 3116** that the supplied string is nul-terminated, then there is a small 3117** performance advantage to be gained by passing an nByte parameter that 3118** is equal to the number of bytes in the input string <i>including</i> 3119** the nul-terminator bytes as this saves SQLite from having to 3120** make a copy of the input string. 3121** 3122** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3123** past the end of the first SQL statement in zSql. These routines only 3124** compile the first statement in zSql, so *pzTail is left pointing to 3125** what remains uncompiled. 3126** 3127** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3128** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3129** to NULL. ^If the input text contains no SQL (if the input is an empty 3130** string or a comment) then *ppStmt is set to NULL. 3131** The calling procedure is responsible for deleting the compiled 3132** SQL statement using [sqlite3_finalize()] after it has finished with it. 3133** ppStmt may not be NULL. 3134** 3135** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3136** otherwise an [error code] is returned. 3137** 3138** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3139** recommended for all new programs. The two older interfaces are retained 3140** for backwards compatibility, but their use is discouraged. 3141** ^In the "v2" interfaces, the prepared statement 3142** that is returned (the [sqlite3_stmt] object) contains a copy of the 3143** original SQL text. This causes the [sqlite3_step()] interface to 3144** behave differently in three ways: 3145** 3146** <ol> 3147** <li> 3148** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3149** always used to do, [sqlite3_step()] will automatically recompile the SQL 3150** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3151** retries will occur before sqlite3_step() gives up and returns an error. 3152** </li> 3153** 3154** <li> 3155** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3156** [error codes] or [extended error codes]. ^The legacy behavior was that 3157** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3158** and the application would have to make a second call to [sqlite3_reset()] 3159** in order to find the underlying cause of the problem. With the "v2" prepare 3160** interfaces, the underlying reason for the error is returned immediately. 3161** </li> 3162** 3163** <li> 3164** ^If the specific value bound to [parameter | host parameter] in the 3165** WHERE clause might influence the choice of query plan for a statement, 3166** then the statement will be automatically recompiled, as if there had been 3167** a schema change, on the first [sqlite3_step()] call following any change 3168** to the [sqlite3_bind_text | bindings] of that [parameter]. 3169** ^The specific value of WHERE-clause [parameter] might influence the 3170** choice of query plan if the parameter is the left-hand side of a [LIKE] 3171** or [GLOB] operator or if the parameter is compared to an indexed column 3172** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3173** </li> 3174** </ol> 3175*/ 3176int sqlite3_prepare( 3177 sqlite3 *db, /* Database handle */ 3178 const char *zSql, /* SQL statement, UTF-8 encoded */ 3179 int nByte, /* Maximum length of zSql in bytes. */ 3180 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3181 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3182); 3183int sqlite3_prepare_v2( 3184 sqlite3 *db, /* Database handle */ 3185 const char *zSql, /* SQL statement, UTF-8 encoded */ 3186 int nByte, /* Maximum length of zSql in bytes. */ 3187 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3188 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3189); 3190int sqlite3_prepare16( 3191 sqlite3 *db, /* Database handle */ 3192 const void *zSql, /* SQL statement, UTF-16 encoded */ 3193 int nByte, /* Maximum length of zSql in bytes. */ 3194 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3195 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3196); 3197int sqlite3_prepare16_v2( 3198 sqlite3 *db, /* Database handle */ 3199 const void *zSql, /* SQL statement, UTF-16 encoded */ 3200 int nByte, /* Maximum length of zSql in bytes. */ 3201 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3202 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3203); 3204 3205/* 3206** CAPI3REF: Retrieving Statement SQL 3207** 3208** ^This interface can be used to retrieve a saved copy of the original 3209** SQL text used to create a [prepared statement] if that statement was 3210** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3211*/ 3212const char *sqlite3_sql(sqlite3_stmt *pStmt); 3213 3214/* 3215** CAPI3REF: Determine If An SQL Statement Writes The Database 3216** 3217** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3218** and only if the [prepared statement] X makes no direct changes to 3219** the content of the database file. 3220** 3221** Note that [application-defined SQL functions] or 3222** [virtual tables] might change the database indirectly as a side effect. 3223** ^(For example, if an application defines a function "eval()" that 3224** calls [sqlite3_exec()], then the following SQL statement would 3225** change the database file through side-effects: 3226** 3227** <blockquote><pre> 3228** SELECT eval('DELETE FROM t1') FROM t2; 3229** </pre></blockquote> 3230** 3231** But because the [SELECT] statement does not change the database file 3232** directly, sqlite3_stmt_readonly() would still return true.)^ 3233** 3234** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3235** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3236** since the statements themselves do not actually modify the database but 3237** rather they control the timing of when other statements modify the 3238** database. ^The [ATTACH] and [DETACH] statements also cause 3239** sqlite3_stmt_readonly() to return true since, while those statements 3240** change the configuration of a database connection, they do not make 3241** changes to the content of the database files on disk. 3242*/ 3243int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3244 3245/* 3246** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3247** 3248** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3249** [prepared statement] S has been stepped at least once using 3250** [sqlite3_step(S)] but has not run to completion and/or has not 3251** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3252** interface returns false if S is a NULL pointer. If S is not a 3253** NULL pointer and is not a pointer to a valid [prepared statement] 3254** object, then the behavior is undefined and probably undesirable. 3255** 3256** This interface can be used in combination [sqlite3_next_stmt()] 3257** to locate all prepared statements associated with a database 3258** connection that are in need of being reset. This can be used, 3259** for example, in diagnostic routines to search for prepared 3260** statements that are holding a transaction open. 3261*/ 3262int sqlite3_stmt_busy(sqlite3_stmt*); 3263 3264/* 3265** CAPI3REF: Dynamically Typed Value Object 3266** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3267** 3268** SQLite uses the sqlite3_value object to represent all values 3269** that can be stored in a database table. SQLite uses dynamic typing 3270** for the values it stores. ^Values stored in sqlite3_value objects 3271** can be integers, floating point values, strings, BLOBs, or NULL. 3272** 3273** An sqlite3_value object may be either "protected" or "unprotected". 3274** Some interfaces require a protected sqlite3_value. Other interfaces 3275** will accept either a protected or an unprotected sqlite3_value. 3276** Every interface that accepts sqlite3_value arguments specifies 3277** whether or not it requires a protected sqlite3_value. 3278** 3279** The terms "protected" and "unprotected" refer to whether or not 3280** a mutex is held. An internal mutex is held for a protected 3281** sqlite3_value object but no mutex is held for an unprotected 3282** sqlite3_value object. If SQLite is compiled to be single-threaded 3283** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3284** or if SQLite is run in one of reduced mutex modes 3285** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3286** then there is no distinction between protected and unprotected 3287** sqlite3_value objects and they can be used interchangeably. However, 3288** for maximum code portability it is recommended that applications 3289** still make the distinction between protected and unprotected 3290** sqlite3_value objects even when not strictly required. 3291** 3292** ^The sqlite3_value objects that are passed as parameters into the 3293** implementation of [application-defined SQL functions] are protected. 3294** ^The sqlite3_value object returned by 3295** [sqlite3_column_value()] is unprotected. 3296** Unprotected sqlite3_value objects may only be used with 3297** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3298** The [sqlite3_value_blob | sqlite3_value_type()] family of 3299** interfaces require protected sqlite3_value objects. 3300*/ 3301typedef struct Mem sqlite3_value; 3302 3303/* 3304** CAPI3REF: SQL Function Context Object 3305** 3306** The context in which an SQL function executes is stored in an 3307** sqlite3_context object. ^A pointer to an sqlite3_context object 3308** is always first parameter to [application-defined SQL functions]. 3309** The application-defined SQL function implementation will pass this 3310** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3311** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3312** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3313** and/or [sqlite3_set_auxdata()]. 3314*/ 3315typedef struct sqlite3_context sqlite3_context; 3316 3317/* 3318** CAPI3REF: Binding Values To Prepared Statements 3319** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3320** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3321** 3322** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3323** literals may be replaced by a [parameter] that matches one of following 3324** templates: 3325** 3326** <ul> 3327** <li> ? 3328** <li> ?NNN 3329** <li> :VVV 3330** <li> @VVV 3331** <li> $VVV 3332** </ul> 3333** 3334** In the templates above, NNN represents an integer literal, 3335** and VVV represents an alphanumeric identifier.)^ ^The values of these 3336** parameters (also called "host parameter names" or "SQL parameters") 3337** can be set using the sqlite3_bind_*() routines defined here. 3338** 3339** ^The first argument to the sqlite3_bind_*() routines is always 3340** a pointer to the [sqlite3_stmt] object returned from 3341** [sqlite3_prepare_v2()] or its variants. 3342** 3343** ^The second argument is the index of the SQL parameter to be set. 3344** ^The leftmost SQL parameter has an index of 1. ^When the same named 3345** SQL parameter is used more than once, second and subsequent 3346** occurrences have the same index as the first occurrence. 3347** ^The index for named parameters can be looked up using the 3348** [sqlite3_bind_parameter_index()] API if desired. ^The index 3349** for "?NNN" parameters is the value of NNN. 3350** ^The NNN value must be between 1 and the [sqlite3_limit()] 3351** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3352** 3353** ^The third argument is the value to bind to the parameter. 3354** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3355** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3356** is ignored and the end result is the same as sqlite3_bind_null(). 3357** 3358** ^(In those routines that have a fourth argument, its value is the 3359** number of bytes in the parameter. To be clear: the value is the 3360** number of <u>bytes</u> in the value, not the number of characters.)^ 3361** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3362** is negative, then the length of the string is 3363** the number of bytes up to the first zero terminator. 3364** If the fourth parameter to sqlite3_bind_blob() is negative, then 3365** the behavior is undefined. 3366** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3367** or sqlite3_bind_text16() then that parameter must be the byte offset 3368** where the NUL terminator would occur assuming the string were NUL 3369** terminated. If any NUL characters occur at byte offsets less than 3370** the value of the fourth parameter then the resulting string value will 3371** contain embedded NULs. The result of expressions involving strings 3372** with embedded NULs is undefined. 3373** 3374** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3375** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3376** string after SQLite has finished with it. ^The destructor is called 3377** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3378** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3379** ^If the fifth argument is 3380** the special value [SQLITE_STATIC], then SQLite assumes that the 3381** information is in static, unmanaged space and does not need to be freed. 3382** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3383** SQLite makes its own private copy of the data immediately, before 3384** the sqlite3_bind_*() routine returns. 3385** 3386** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3387** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3388** (just an integer to hold its size) while it is being processed. 3389** Zeroblobs are intended to serve as placeholders for BLOBs whose 3390** content is later written using 3391** [sqlite3_blob_open | incremental BLOB I/O] routines. 3392** ^A negative value for the zeroblob results in a zero-length BLOB. 3393** 3394** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3395** for the [prepared statement] or with a prepared statement for which 3396** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3397** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3398** routine is passed a [prepared statement] that has been finalized, the 3399** result is undefined and probably harmful. 3400** 3401** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3402** ^Unbound parameters are interpreted as NULL. 3403** 3404** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3405** [error code] if anything goes wrong. 3406** ^[SQLITE_RANGE] is returned if the parameter 3407** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3408** 3409** See also: [sqlite3_bind_parameter_count()], 3410** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3411*/ 3412int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3413int sqlite3_bind_double(sqlite3_stmt*, int, double); 3414int sqlite3_bind_int(sqlite3_stmt*, int, int); 3415int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3416int sqlite3_bind_null(sqlite3_stmt*, int); 3417int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3418int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3419int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3420int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3421 3422/* 3423** CAPI3REF: Number Of SQL Parameters 3424** 3425** ^This routine can be used to find the number of [SQL parameters] 3426** in a [prepared statement]. SQL parameters are tokens of the 3427** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3428** placeholders for values that are [sqlite3_bind_blob | bound] 3429** to the parameters at a later time. 3430** 3431** ^(This routine actually returns the index of the largest (rightmost) 3432** parameter. For all forms except ?NNN, this will correspond to the 3433** number of unique parameters. If parameters of the ?NNN form are used, 3434** there may be gaps in the list.)^ 3435** 3436** See also: [sqlite3_bind_blob|sqlite3_bind()], 3437** [sqlite3_bind_parameter_name()], and 3438** [sqlite3_bind_parameter_index()]. 3439*/ 3440int sqlite3_bind_parameter_count(sqlite3_stmt*); 3441 3442/* 3443** CAPI3REF: Name Of A Host Parameter 3444** 3445** ^The sqlite3_bind_parameter_name(P,N) interface returns 3446** the name of the N-th [SQL parameter] in the [prepared statement] P. 3447** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3448** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3449** respectively. 3450** In other words, the initial ":" or "$" or "@" or "?" 3451** is included as part of the name.)^ 3452** ^Parameters of the form "?" without a following integer have no name 3453** and are referred to as "nameless" or "anonymous parameters". 3454** 3455** ^The first host parameter has an index of 1, not 0. 3456** 3457** ^If the value N is out of range or if the N-th parameter is 3458** nameless, then NULL is returned. ^The returned string is 3459** always in UTF-8 encoding even if the named parameter was 3460** originally specified as UTF-16 in [sqlite3_prepare16()] or 3461** [sqlite3_prepare16_v2()]. 3462** 3463** See also: [sqlite3_bind_blob|sqlite3_bind()], 3464** [sqlite3_bind_parameter_count()], and 3465** [sqlite3_bind_parameter_index()]. 3466*/ 3467const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3468 3469/* 3470** CAPI3REF: Index Of A Parameter With A Given Name 3471** 3472** ^Return the index of an SQL parameter given its name. ^The 3473** index value returned is suitable for use as the second 3474** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3475** is returned if no matching parameter is found. ^The parameter 3476** name must be given in UTF-8 even if the original statement 3477** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3478** 3479** See also: [sqlite3_bind_blob|sqlite3_bind()], 3480** [sqlite3_bind_parameter_count()], and 3481** [sqlite3_bind_parameter_index()]. 3482*/ 3483int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3484 3485/* 3486** CAPI3REF: Reset All Bindings On A Prepared Statement 3487** 3488** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3489** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3490** ^Use this routine to reset all host parameters to NULL. 3491*/ 3492int sqlite3_clear_bindings(sqlite3_stmt*); 3493 3494/* 3495** CAPI3REF: Number Of Columns In A Result Set 3496** 3497** ^Return the number of columns in the result set returned by the 3498** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3499** statement that does not return data (for example an [UPDATE]). 3500** 3501** See also: [sqlite3_data_count()] 3502*/ 3503int sqlite3_column_count(sqlite3_stmt *pStmt); 3504 3505/* 3506** CAPI3REF: Column Names In A Result Set 3507** 3508** ^These routines return the name assigned to a particular column 3509** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3510** interface returns a pointer to a zero-terminated UTF-8 string 3511** and sqlite3_column_name16() returns a pointer to a zero-terminated 3512** UTF-16 string. ^The first parameter is the [prepared statement] 3513** that implements the [SELECT] statement. ^The second parameter is the 3514** column number. ^The leftmost column is number 0. 3515** 3516** ^The returned string pointer is valid until either the [prepared statement] 3517** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3518** reprepared by the first call to [sqlite3_step()] for a particular run 3519** or until the next call to 3520** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3521** 3522** ^If sqlite3_malloc() fails during the processing of either routine 3523** (for example during a conversion from UTF-8 to UTF-16) then a 3524** NULL pointer is returned. 3525** 3526** ^The name of a result column is the value of the "AS" clause for 3527** that column, if there is an AS clause. If there is no AS clause 3528** then the name of the column is unspecified and may change from 3529** one release of SQLite to the next. 3530*/ 3531const char *sqlite3_column_name(sqlite3_stmt*, int N); 3532const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3533 3534/* 3535** CAPI3REF: Source Of Data In A Query Result 3536** 3537** ^These routines provide a means to determine the database, table, and 3538** table column that is the origin of a particular result column in 3539** [SELECT] statement. 3540** ^The name of the database or table or column can be returned as 3541** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3542** the database name, the _table_ routines return the table name, and 3543** the origin_ routines return the column name. 3544** ^The returned string is valid until the [prepared statement] is destroyed 3545** using [sqlite3_finalize()] or until the statement is automatically 3546** reprepared by the first call to [sqlite3_step()] for a particular run 3547** or until the same information is requested 3548** again in a different encoding. 3549** 3550** ^The names returned are the original un-aliased names of the 3551** database, table, and column. 3552** 3553** ^The first argument to these interfaces is a [prepared statement]. 3554** ^These functions return information about the Nth result column returned by 3555** the statement, where N is the second function argument. 3556** ^The left-most column is column 0 for these routines. 3557** 3558** ^If the Nth column returned by the statement is an expression or 3559** subquery and is not a column value, then all of these functions return 3560** NULL. ^These routine might also return NULL if a memory allocation error 3561** occurs. ^Otherwise, they return the name of the attached database, table, 3562** or column that query result column was extracted from. 3563** 3564** ^As with all other SQLite APIs, those whose names end with "16" return 3565** UTF-16 encoded strings and the other functions return UTF-8. 3566** 3567** ^These APIs are only available if the library was compiled with the 3568** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3569** 3570** If two or more threads call one or more of these routines against the same 3571** prepared statement and column at the same time then the results are 3572** undefined. 3573** 3574** If two or more threads call one or more 3575** [sqlite3_column_database_name | column metadata interfaces] 3576** for the same [prepared statement] and result column 3577** at the same time then the results are undefined. 3578*/ 3579const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3580const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3581const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3582const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3583const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3584const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3585 3586/* 3587** CAPI3REF: Declared Datatype Of A Query Result 3588** 3589** ^(The first parameter is a [prepared statement]. 3590** If this statement is a [SELECT] statement and the Nth column of the 3591** returned result set of that [SELECT] is a table column (not an 3592** expression or subquery) then the declared type of the table 3593** column is returned.)^ ^If the Nth column of the result set is an 3594** expression or subquery, then a NULL pointer is returned. 3595** ^The returned string is always UTF-8 encoded. 3596** 3597** ^(For example, given the database schema: 3598** 3599** CREATE TABLE t1(c1 VARIANT); 3600** 3601** and the following statement to be compiled: 3602** 3603** SELECT c1 + 1, c1 FROM t1; 3604** 3605** this routine would return the string "VARIANT" for the second result 3606** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3607** 3608** ^SQLite uses dynamic run-time typing. ^So just because a column 3609** is declared to contain a particular type does not mean that the 3610** data stored in that column is of the declared type. SQLite is 3611** strongly typed, but the typing is dynamic not static. ^Type 3612** is associated with individual values, not with the containers 3613** used to hold those values. 3614*/ 3615const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3616const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3617 3618/* 3619** CAPI3REF: Evaluate An SQL Statement 3620** 3621** After a [prepared statement] has been prepared using either 3622** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3623** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3624** must be called one or more times to evaluate the statement. 3625** 3626** The details of the behavior of the sqlite3_step() interface depend 3627** on whether the statement was prepared using the newer "v2" interface 3628** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3629** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3630** new "v2" interface is recommended for new applications but the legacy 3631** interface will continue to be supported. 3632** 3633** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3634** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3635** ^With the "v2" interface, any of the other [result codes] or 3636** [extended result codes] might be returned as well. 3637** 3638** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3639** database locks it needs to do its job. ^If the statement is a [COMMIT] 3640** or occurs outside of an explicit transaction, then you can retry the 3641** statement. If the statement is not a [COMMIT] and occurs within an 3642** explicit transaction then you should rollback the transaction before 3643** continuing. 3644** 3645** ^[SQLITE_DONE] means that the statement has finished executing 3646** successfully. sqlite3_step() should not be called again on this virtual 3647** machine without first calling [sqlite3_reset()] to reset the virtual 3648** machine back to its initial state. 3649** 3650** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3651** is returned each time a new row of data is ready for processing by the 3652** caller. The values may be accessed using the [column access functions]. 3653** sqlite3_step() is called again to retrieve the next row of data. 3654** 3655** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3656** violation) has occurred. sqlite3_step() should not be called again on 3657** the VM. More information may be found by calling [sqlite3_errmsg()]. 3658** ^With the legacy interface, a more specific error code (for example, 3659** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3660** can be obtained by calling [sqlite3_reset()] on the 3661** [prepared statement]. ^In the "v2" interface, 3662** the more specific error code is returned directly by sqlite3_step(). 3663** 3664** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3665** Perhaps it was called on a [prepared statement] that has 3666** already been [sqlite3_finalize | finalized] or on one that had 3667** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3668** be the case that the same database connection is being used by two or 3669** more threads at the same moment in time. 3670** 3671** For all versions of SQLite up to and including 3.6.23.1, a call to 3672** [sqlite3_reset()] was required after sqlite3_step() returned anything 3673** other than [SQLITE_ROW] before any subsequent invocation of 3674** sqlite3_step(). Failure to reset the prepared statement using 3675** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3676** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3677** calling [sqlite3_reset()] automatically in this circumstance rather 3678** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3679** break because any application that ever receives an SQLITE_MISUSE error 3680** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3681** can be used to restore the legacy behavior. 3682** 3683** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3684** API always returns a generic error code, [SQLITE_ERROR], following any 3685** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3686** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3687** specific [error codes] that better describes the error. 3688** We admit that this is a goofy design. The problem has been fixed 3689** with the "v2" interface. If you prepare all of your SQL statements 3690** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3691** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3692** then the more specific [error codes] are returned directly 3693** by sqlite3_step(). The use of the "v2" interface is recommended. 3694*/ 3695int sqlite3_step(sqlite3_stmt*); 3696 3697/* 3698** CAPI3REF: Number of columns in a result set 3699** 3700** ^The sqlite3_data_count(P) interface returns the number of columns in the 3701** current row of the result set of [prepared statement] P. 3702** ^If prepared statement P does not have results ready to return 3703** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3704** interfaces) then sqlite3_data_count(P) returns 0. 3705** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3706** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3707** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3708** will return non-zero if previous call to [sqlite3_step](P) returned 3709** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3710** where it always returns zero since each step of that multi-step 3711** pragma returns 0 columns of data. 3712** 3713** See also: [sqlite3_column_count()] 3714*/ 3715int sqlite3_data_count(sqlite3_stmt *pStmt); 3716 3717/* 3718** CAPI3REF: Fundamental Datatypes 3719** KEYWORDS: SQLITE_TEXT 3720** 3721** ^(Every value in SQLite has one of five fundamental datatypes: 3722** 3723** <ul> 3724** <li> 64-bit signed integer 3725** <li> 64-bit IEEE floating point number 3726** <li> string 3727** <li> BLOB 3728** <li> NULL 3729** </ul>)^ 3730** 3731** These constants are codes for each of those types. 3732** 3733** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3734** for a completely different meaning. Software that links against both 3735** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3736** SQLITE_TEXT. 3737*/ 3738#define SQLITE_INTEGER 1 3739#define SQLITE_FLOAT 2 3740#define SQLITE_BLOB 4 3741#define SQLITE_NULL 5 3742#ifdef SQLITE_TEXT 3743# undef SQLITE_TEXT 3744#else 3745# define SQLITE_TEXT 3 3746#endif 3747#define SQLITE3_TEXT 3 3748 3749/* 3750** CAPI3REF: Result Values From A Query 3751** KEYWORDS: {column access functions} 3752** 3753** These routines form the "result set" interface. 3754** 3755** ^These routines return information about a single column of the current 3756** result row of a query. ^In every case the first argument is a pointer 3757** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3758** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3759** and the second argument is the index of the column for which information 3760** should be returned. ^The leftmost column of the result set has the index 0. 3761** ^The number of columns in the result can be determined using 3762** [sqlite3_column_count()]. 3763** 3764** If the SQL statement does not currently point to a valid row, or if the 3765** column index is out of range, the result is undefined. 3766** These routines may only be called when the most recent call to 3767** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3768** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3769** If any of these routines are called after [sqlite3_reset()] or 3770** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3771** something other than [SQLITE_ROW], the results are undefined. 3772** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3773** are called from a different thread while any of these routines 3774** are pending, then the results are undefined. 3775** 3776** ^The sqlite3_column_type() routine returns the 3777** [SQLITE_INTEGER | datatype code] for the initial data type 3778** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3779** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3780** returned by sqlite3_column_type() is only meaningful if no type 3781** conversions have occurred as described below. After a type conversion, 3782** the value returned by sqlite3_column_type() is undefined. Future 3783** versions of SQLite may change the behavior of sqlite3_column_type() 3784** following a type conversion. 3785** 3786** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3787** routine returns the number of bytes in that BLOB or string. 3788** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3789** the string to UTF-8 and then returns the number of bytes. 3790** ^If the result is a numeric value then sqlite3_column_bytes() uses 3791** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3792** the number of bytes in that string. 3793** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3794** 3795** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3796** routine returns the number of bytes in that BLOB or string. 3797** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3798** the string to UTF-16 and then returns the number of bytes. 3799** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3800** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3801** the number of bytes in that string. 3802** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3803** 3804** ^The values returned by [sqlite3_column_bytes()] and 3805** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3806** of the string. ^For clarity: the values returned by 3807** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3808** bytes in the string, not the number of characters. 3809** 3810** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3811** even empty strings, are always zero-terminated. ^The return 3812** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3813** 3814** ^The object returned by [sqlite3_column_value()] is an 3815** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3816** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3817** If the [unprotected sqlite3_value] object returned by 3818** [sqlite3_column_value()] is used in any other way, including calls 3819** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3820** or [sqlite3_value_bytes()], then the behavior is undefined. 3821** 3822** These routines attempt to convert the value where appropriate. ^For 3823** example, if the internal representation is FLOAT and a text result 3824** is requested, [sqlite3_snprintf()] is used internally to perform the 3825** conversion automatically. ^(The following table details the conversions 3826** that are applied: 3827** 3828** <blockquote> 3829** <table border="1"> 3830** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3831** 3832** <tr><td> NULL <td> INTEGER <td> Result is 0 3833** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3834** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3835** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3836** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3837** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3838** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3839** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3840** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3841** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3842** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3843** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3844** <tr><td> TEXT <td> BLOB <td> No change 3845** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3846** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3847** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3848** </table> 3849** </blockquote>)^ 3850** 3851** The table above makes reference to standard C library functions atoi() 3852** and atof(). SQLite does not really use these functions. It has its 3853** own equivalent internal routines. The atoi() and atof() names are 3854** used in the table for brevity and because they are familiar to most 3855** C programmers. 3856** 3857** Note that when type conversions occur, pointers returned by prior 3858** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3859** sqlite3_column_text16() may be invalidated. 3860** Type conversions and pointer invalidations might occur 3861** in the following cases: 3862** 3863** <ul> 3864** <li> The initial content is a BLOB and sqlite3_column_text() or 3865** sqlite3_column_text16() is called. A zero-terminator might 3866** need to be added to the string.</li> 3867** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3868** sqlite3_column_text16() is called. The content must be converted 3869** to UTF-16.</li> 3870** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3871** sqlite3_column_text() is called. The content must be converted 3872** to UTF-8.</li> 3873** </ul> 3874** 3875** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3876** not invalidate a prior pointer, though of course the content of the buffer 3877** that the prior pointer references will have been modified. Other kinds 3878** of conversion are done in place when it is possible, but sometimes they 3879** are not possible and in those cases prior pointers are invalidated. 3880** 3881** The safest and easiest to remember policy is to invoke these routines 3882** in one of the following ways: 3883** 3884** <ul> 3885** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3886** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3887** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3888** </ul> 3889** 3890** In other words, you should call sqlite3_column_text(), 3891** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3892** into the desired format, then invoke sqlite3_column_bytes() or 3893** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3894** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3895** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3896** with calls to sqlite3_column_bytes(). 3897** 3898** ^The pointers returned are valid until a type conversion occurs as 3899** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3900** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3901** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3902** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3903** [sqlite3_free()]. 3904** 3905** ^(If a memory allocation error occurs during the evaluation of any 3906** of these routines, a default value is returned. The default value 3907** is either the integer 0, the floating point number 0.0, or a NULL 3908** pointer. Subsequent calls to [sqlite3_errcode()] will return 3909** [SQLITE_NOMEM].)^ 3910*/ 3911const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3912int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3913int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3914double sqlite3_column_double(sqlite3_stmt*, int iCol); 3915int sqlite3_column_int(sqlite3_stmt*, int iCol); 3916sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3917const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3918const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3919int sqlite3_column_type(sqlite3_stmt*, int iCol); 3920sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3921 3922/* 3923** CAPI3REF: Destroy A Prepared Statement Object 3924** 3925** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3926** ^If the most recent evaluation of the statement encountered no errors 3927** or if the statement is never been evaluated, then sqlite3_finalize() returns 3928** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3929** sqlite3_finalize(S) returns the appropriate [error code] or 3930** [extended error code]. 3931** 3932** ^The sqlite3_finalize(S) routine can be called at any point during 3933** the life cycle of [prepared statement] S: 3934** before statement S is ever evaluated, after 3935** one or more calls to [sqlite3_reset()], or after any call 3936** to [sqlite3_step()] regardless of whether or not the statement has 3937** completed execution. 3938** 3939** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3940** 3941** The application must finalize every [prepared statement] in order to avoid 3942** resource leaks. It is a grievous error for the application to try to use 3943** a prepared statement after it has been finalized. Any use of a prepared 3944** statement after it has been finalized can result in undefined and 3945** undesirable behavior such as segfaults and heap corruption. 3946*/ 3947int sqlite3_finalize(sqlite3_stmt *pStmt); 3948 3949/* 3950** CAPI3REF: Reset A Prepared Statement Object 3951** 3952** The sqlite3_reset() function is called to reset a [prepared statement] 3953** object back to its initial state, ready to be re-executed. 3954** ^Any SQL statement variables that had values bound to them using 3955** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3956** Use [sqlite3_clear_bindings()] to reset the bindings. 3957** 3958** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3959** back to the beginning of its program. 3960** 3961** ^If the most recent call to [sqlite3_step(S)] for the 3962** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3963** or if [sqlite3_step(S)] has never before been called on S, 3964** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3965** 3966** ^If the most recent call to [sqlite3_step(S)] for the 3967** [prepared statement] S indicated an error, then 3968** [sqlite3_reset(S)] returns an appropriate [error code]. 3969** 3970** ^The [sqlite3_reset(S)] interface does not change the values 3971** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3972*/ 3973int sqlite3_reset(sqlite3_stmt *pStmt); 3974 3975/* 3976** CAPI3REF: Create Or Redefine SQL Functions 3977** KEYWORDS: {function creation routines} 3978** KEYWORDS: {application-defined SQL function} 3979** KEYWORDS: {application-defined SQL functions} 3980** 3981** ^These functions (collectively known as "function creation routines") 3982** are used to add SQL functions or aggregates or to redefine the behavior 3983** of existing SQL functions or aggregates. The only differences between 3984** these routines are the text encoding expected for 3985** the second parameter (the name of the function being created) 3986** and the presence or absence of a destructor callback for 3987** the application data pointer. 3988** 3989** ^The first parameter is the [database connection] to which the SQL 3990** function is to be added. ^If an application uses more than one database 3991** connection then application-defined SQL functions must be added 3992** to each database connection separately. 3993** 3994** ^The second parameter is the name of the SQL function to be created or 3995** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3996** representation, exclusive of the zero-terminator. ^Note that the name 3997** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3998** ^Any attempt to create a function with a longer name 3999** will result in [SQLITE_MISUSE] being returned. 4000** 4001** ^The third parameter (nArg) 4002** is the number of arguments that the SQL function or 4003** aggregate takes. ^If this parameter is -1, then the SQL function or 4004** aggregate may take any number of arguments between 0 and the limit 4005** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4006** parameter is less than -1 or greater than 127 then the behavior is 4007** undefined. 4008** 4009** ^The fourth parameter, eTextRep, specifies what 4010** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4011** its parameters. The application should set this parameter to 4012** [SQLITE_UTF16LE] if the function implementation invokes 4013** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4014** implementation invokes [sqlite3_value_text16be()] on an input, or 4015** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4016** otherwise. ^The same SQL function may be registered multiple times using 4017** different preferred text encodings, with different implementations for 4018** each encoding. 4019** ^When multiple implementations of the same function are available, SQLite 4020** will pick the one that involves the least amount of data conversion. 4021** 4022** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4023** to signal that the function will always return the same result given 4024** the same inputs within a single SQL statement. Most SQL functions are 4025** deterministic. The built-in [random()] SQL function is an example of a 4026** function that is not deterministic. The SQLite query planner is able to 4027** perform additional optimizations on deterministic functions, so use 4028** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4029** 4030** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4031** function can gain access to this pointer using [sqlite3_user_data()].)^ 4032** 4033** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4034** pointers to C-language functions that implement the SQL function or 4035** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4036** callback only; NULL pointers must be passed as the xStep and xFinal 4037** parameters. ^An aggregate SQL function requires an implementation of xStep 4038** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4039** SQL function or aggregate, pass NULL pointers for all three function 4040** callbacks. 4041** 4042** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4043** then it is destructor for the application data pointer. 4044** The destructor is invoked when the function is deleted, either by being 4045** overloaded or when the database connection closes.)^ 4046** ^The destructor is also invoked if the call to 4047** sqlite3_create_function_v2() fails. 4048** ^When the destructor callback of the tenth parameter is invoked, it 4049** is passed a single argument which is a copy of the application data 4050** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4051** 4052** ^It is permitted to register multiple implementations of the same 4053** functions with the same name but with either differing numbers of 4054** arguments or differing preferred text encodings. ^SQLite will use 4055** the implementation that most closely matches the way in which the 4056** SQL function is used. ^A function implementation with a non-negative 4057** nArg parameter is a better match than a function implementation with 4058** a negative nArg. ^A function where the preferred text encoding 4059** matches the database encoding is a better 4060** match than a function where the encoding is different. 4061** ^A function where the encoding difference is between UTF16le and UTF16be 4062** is a closer match than a function where the encoding difference is 4063** between UTF8 and UTF16. 4064** 4065** ^Built-in functions may be overloaded by new application-defined functions. 4066** 4067** ^An application-defined function is permitted to call other 4068** SQLite interfaces. However, such calls must not 4069** close the database connection nor finalize or reset the prepared 4070** statement in which the function is running. 4071*/ 4072int sqlite3_create_function( 4073 sqlite3 *db, 4074 const char *zFunctionName, 4075 int nArg, 4076 int eTextRep, 4077 void *pApp, 4078 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4079 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4080 void (*xFinal)(sqlite3_context*) 4081); 4082int sqlite3_create_function16( 4083 sqlite3 *db, 4084 const void *zFunctionName, 4085 int nArg, 4086 int eTextRep, 4087 void *pApp, 4088 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4089 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4090 void (*xFinal)(sqlite3_context*) 4091); 4092int sqlite3_create_function_v2( 4093 sqlite3 *db, 4094 const char *zFunctionName, 4095 int nArg, 4096 int eTextRep, 4097 void *pApp, 4098 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4099 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4100 void (*xFinal)(sqlite3_context*), 4101 void(*xDestroy)(void*) 4102); 4103 4104/* 4105** CAPI3REF: Text Encodings 4106** 4107** These constant define integer codes that represent the various 4108** text encodings supported by SQLite. 4109*/ 4110#define SQLITE_UTF8 1 4111#define SQLITE_UTF16LE 2 4112#define SQLITE_UTF16BE 3 4113#define SQLITE_UTF16 4 /* Use native byte order */ 4114#define SQLITE_ANY 5 /* Deprecated */ 4115#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4116 4117/* 4118** CAPI3REF: Function Flags 4119** 4120** These constants may be ORed together with the 4121** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4122** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4123** [sqlite3_create_function_v2()]. 4124*/ 4125#define SQLITE_DETERMINISTIC 0x800 4126 4127/* 4128** CAPI3REF: Deprecated Functions 4129** DEPRECATED 4130** 4131** These functions are [deprecated]. In order to maintain 4132** backwards compatibility with older code, these functions continue 4133** to be supported. However, new applications should avoid 4134** the use of these functions. To help encourage people to avoid 4135** using these functions, we are not going to tell you what they do. 4136*/ 4137#ifndef SQLITE_OMIT_DEPRECATED 4138SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4139SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4140SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4141SQLITE_DEPRECATED int sqlite3_global_recover(void); 4142SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4143SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4144 void*,sqlite3_int64); 4145#endif 4146 4147/* 4148** CAPI3REF: Obtaining SQL Function Parameter Values 4149** 4150** The C-language implementation of SQL functions and aggregates uses 4151** this set of interface routines to access the parameter values on 4152** the function or aggregate. 4153** 4154** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4155** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4156** define callbacks that implement the SQL functions and aggregates. 4157** The 3rd parameter to these callbacks is an array of pointers to 4158** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4159** each parameter to the SQL function. These routines are used to 4160** extract values from the [sqlite3_value] objects. 4161** 4162** These routines work only with [protected sqlite3_value] objects. 4163** Any attempt to use these routines on an [unprotected sqlite3_value] 4164** object results in undefined behavior. 4165** 4166** ^These routines work just like the corresponding [column access functions] 4167** except that these routines take a single [protected sqlite3_value] object 4168** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4169** 4170** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4171** in the native byte-order of the host machine. ^The 4172** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4173** extract UTF-16 strings as big-endian and little-endian respectively. 4174** 4175** ^(The sqlite3_value_numeric_type() interface attempts to apply 4176** numeric affinity to the value. This means that an attempt is 4177** made to convert the value to an integer or floating point. If 4178** such a conversion is possible without loss of information (in other 4179** words, if the value is a string that looks like a number) 4180** then the conversion is performed. Otherwise no conversion occurs. 4181** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4182** 4183** Please pay particular attention to the fact that the pointer returned 4184** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4185** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4186** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4187** or [sqlite3_value_text16()]. 4188** 4189** These routines must be called from the same thread as 4190** the SQL function that supplied the [sqlite3_value*] parameters. 4191*/ 4192const void *sqlite3_value_blob(sqlite3_value*); 4193int sqlite3_value_bytes(sqlite3_value*); 4194int sqlite3_value_bytes16(sqlite3_value*); 4195double sqlite3_value_double(sqlite3_value*); 4196int sqlite3_value_int(sqlite3_value*); 4197sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4198const unsigned char *sqlite3_value_text(sqlite3_value*); 4199const void *sqlite3_value_text16(sqlite3_value*); 4200const void *sqlite3_value_text16le(sqlite3_value*); 4201const void *sqlite3_value_text16be(sqlite3_value*); 4202int sqlite3_value_type(sqlite3_value*); 4203int sqlite3_value_numeric_type(sqlite3_value*); 4204 4205/* 4206** CAPI3REF: Obtain Aggregate Function Context 4207** 4208** Implementations of aggregate SQL functions use this 4209** routine to allocate memory for storing their state. 4210** 4211** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4212** for a particular aggregate function, SQLite 4213** allocates N of memory, zeroes out that memory, and returns a pointer 4214** to the new memory. ^On second and subsequent calls to 4215** sqlite3_aggregate_context() for the same aggregate function instance, 4216** the same buffer is returned. Sqlite3_aggregate_context() is normally 4217** called once for each invocation of the xStep callback and then one 4218** last time when the xFinal callback is invoked. ^(When no rows match 4219** an aggregate query, the xStep() callback of the aggregate function 4220** implementation is never called and xFinal() is called exactly once. 4221** In those cases, sqlite3_aggregate_context() might be called for the 4222** first time from within xFinal().)^ 4223** 4224** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4225** when first called if N is less than or equal to zero or if a memory 4226** allocate error occurs. 4227** 4228** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4229** determined by the N parameter on first successful call. Changing the 4230** value of N in subsequent call to sqlite3_aggregate_context() within 4231** the same aggregate function instance will not resize the memory 4232** allocation.)^ Within the xFinal callback, it is customary to set 4233** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4234** pointless memory allocations occur. 4235** 4236** ^SQLite automatically frees the memory allocated by 4237** sqlite3_aggregate_context() when the aggregate query concludes. 4238** 4239** The first parameter must be a copy of the 4240** [sqlite3_context | SQL function context] that is the first parameter 4241** to the xStep or xFinal callback routine that implements the aggregate 4242** function. 4243** 4244** This routine must be called from the same thread in which 4245** the aggregate SQL function is running. 4246*/ 4247void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4248 4249/* 4250** CAPI3REF: User Data For Functions 4251** 4252** ^The sqlite3_user_data() interface returns a copy of 4253** the pointer that was the pUserData parameter (the 5th parameter) 4254** of the [sqlite3_create_function()] 4255** and [sqlite3_create_function16()] routines that originally 4256** registered the application defined function. 4257** 4258** This routine must be called from the same thread in which 4259** the application-defined function is running. 4260*/ 4261void *sqlite3_user_data(sqlite3_context*); 4262 4263/* 4264** CAPI3REF: Database Connection For Functions 4265** 4266** ^The sqlite3_context_db_handle() interface returns a copy of 4267** the pointer to the [database connection] (the 1st parameter) 4268** of the [sqlite3_create_function()] 4269** and [sqlite3_create_function16()] routines that originally 4270** registered the application defined function. 4271*/ 4272sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4273 4274/* 4275** CAPI3REF: Function Auxiliary Data 4276** 4277** These functions may be used by (non-aggregate) SQL functions to 4278** associate metadata with argument values. If the same value is passed to 4279** multiple invocations of the same SQL function during query execution, under 4280** some circumstances the associated metadata may be preserved. An example 4281** of where this might be useful is in a regular-expression matching 4282** function. The compiled version of the regular expression can be stored as 4283** metadata associated with the pattern string. 4284** Then as long as the pattern string remains the same, 4285** the compiled regular expression can be reused on multiple 4286** invocations of the same function. 4287** 4288** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4289** associated by the sqlite3_set_auxdata() function with the Nth argument 4290** value to the application-defined function. ^If there is no metadata 4291** associated with the function argument, this sqlite3_get_auxdata() interface 4292** returns a NULL pointer. 4293** 4294** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4295** argument of the application-defined function. ^Subsequent 4296** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4297** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4298** NULL if the metadata has been discarded. 4299** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4300** SQLite will invoke the destructor function X with parameter P exactly 4301** once, when the metadata is discarded. 4302** SQLite is free to discard the metadata at any time, including: <ul> 4303** <li> when the corresponding function parameter changes, or 4304** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4305** SQL statement, or 4306** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4307** <li> during the original sqlite3_set_auxdata() call when a memory 4308** allocation error occurs. </ul>)^ 4309** 4310** Note the last bullet in particular. The destructor X in 4311** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4312** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4313** should be called near the end of the function implementation and the 4314** function implementation should not make any use of P after 4315** sqlite3_set_auxdata() has been called. 4316** 4317** ^(In practice, metadata is preserved between function calls for 4318** function parameters that are compile-time constants, including literal 4319** values and [parameters] and expressions composed from the same.)^ 4320** 4321** These routines must be called from the same thread in which 4322** the SQL function is running. 4323*/ 4324void *sqlite3_get_auxdata(sqlite3_context*, int N); 4325void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4326 4327 4328/* 4329** CAPI3REF: Constants Defining Special Destructor Behavior 4330** 4331** These are special values for the destructor that is passed in as the 4332** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4333** argument is SQLITE_STATIC, it means that the content pointer is constant 4334** and will never change. It does not need to be destroyed. ^The 4335** SQLITE_TRANSIENT value means that the content will likely change in 4336** the near future and that SQLite should make its own private copy of 4337** the content before returning. 4338** 4339** The typedef is necessary to work around problems in certain 4340** C++ compilers. 4341*/ 4342typedef void (*sqlite3_destructor_type)(void*); 4343#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4344#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4345 4346/* 4347** CAPI3REF: Setting The Result Of An SQL Function 4348** 4349** These routines are used by the xFunc or xFinal callbacks that 4350** implement SQL functions and aggregates. See 4351** [sqlite3_create_function()] and [sqlite3_create_function16()] 4352** for additional information. 4353** 4354** These functions work very much like the [parameter binding] family of 4355** functions used to bind values to host parameters in prepared statements. 4356** Refer to the [SQL parameter] documentation for additional information. 4357** 4358** ^The sqlite3_result_blob() interface sets the result from 4359** an application-defined function to be the BLOB whose content is pointed 4360** to by the second parameter and which is N bytes long where N is the 4361** third parameter. 4362** 4363** ^The sqlite3_result_zeroblob() interfaces set the result of 4364** the application-defined function to be a BLOB containing all zero 4365** bytes and N bytes in size, where N is the value of the 2nd parameter. 4366** 4367** ^The sqlite3_result_double() interface sets the result from 4368** an application-defined function to be a floating point value specified 4369** by its 2nd argument. 4370** 4371** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4372** cause the implemented SQL function to throw an exception. 4373** ^SQLite uses the string pointed to by the 4374** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4375** as the text of an error message. ^SQLite interprets the error 4376** message string from sqlite3_result_error() as UTF-8. ^SQLite 4377** interprets the string from sqlite3_result_error16() as UTF-16 in native 4378** byte order. ^If the third parameter to sqlite3_result_error() 4379** or sqlite3_result_error16() is negative then SQLite takes as the error 4380** message all text up through the first zero character. 4381** ^If the third parameter to sqlite3_result_error() or 4382** sqlite3_result_error16() is non-negative then SQLite takes that many 4383** bytes (not characters) from the 2nd parameter as the error message. 4384** ^The sqlite3_result_error() and sqlite3_result_error16() 4385** routines make a private copy of the error message text before 4386** they return. Hence, the calling function can deallocate or 4387** modify the text after they return without harm. 4388** ^The sqlite3_result_error_code() function changes the error code 4389** returned by SQLite as a result of an error in a function. ^By default, 4390** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4391** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4392** 4393** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4394** error indicating that a string or BLOB is too long to represent. 4395** 4396** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4397** error indicating that a memory allocation failed. 4398** 4399** ^The sqlite3_result_int() interface sets the return value 4400** of the application-defined function to be the 32-bit signed integer 4401** value given in the 2nd argument. 4402** ^The sqlite3_result_int64() interface sets the return value 4403** of the application-defined function to be the 64-bit signed integer 4404** value given in the 2nd argument. 4405** 4406** ^The sqlite3_result_null() interface sets the return value 4407** of the application-defined function to be NULL. 4408** 4409** ^The sqlite3_result_text(), sqlite3_result_text16(), 4410** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4411** set the return value of the application-defined function to be 4412** a text string which is represented as UTF-8, UTF-16 native byte order, 4413** UTF-16 little endian, or UTF-16 big endian, respectively. 4414** ^SQLite takes the text result from the application from 4415** the 2nd parameter of the sqlite3_result_text* interfaces. 4416** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4417** is negative, then SQLite takes result text from the 2nd parameter 4418** through the first zero character. 4419** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4420** is non-negative, then as many bytes (not characters) of the text 4421** pointed to by the 2nd parameter are taken as the application-defined 4422** function result. If the 3rd parameter is non-negative, then it 4423** must be the byte offset into the string where the NUL terminator would 4424** appear if the string where NUL terminated. If any NUL characters occur 4425** in the string at a byte offset that is less than the value of the 3rd 4426** parameter, then the resulting string will contain embedded NULs and the 4427** result of expressions operating on strings with embedded NULs is undefined. 4428** ^If the 4th parameter to the sqlite3_result_text* interfaces 4429** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4430** function as the destructor on the text or BLOB result when it has 4431** finished using that result. 4432** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4433** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4434** assumes that the text or BLOB result is in constant space and does not 4435** copy the content of the parameter nor call a destructor on the content 4436** when it has finished using that result. 4437** ^If the 4th parameter to the sqlite3_result_text* interfaces 4438** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4439** then SQLite makes a copy of the result into space obtained from 4440** from [sqlite3_malloc()] before it returns. 4441** 4442** ^The sqlite3_result_value() interface sets the result of 4443** the application-defined function to be a copy the 4444** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4445** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4446** so that the [sqlite3_value] specified in the parameter may change or 4447** be deallocated after sqlite3_result_value() returns without harm. 4448** ^A [protected sqlite3_value] object may always be used where an 4449** [unprotected sqlite3_value] object is required, so either 4450** kind of [sqlite3_value] object can be used with this interface. 4451** 4452** If these routines are called from within the different thread 4453** than the one containing the application-defined function that received 4454** the [sqlite3_context] pointer, the results are undefined. 4455*/ 4456void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4457void sqlite3_result_double(sqlite3_context*, double); 4458void sqlite3_result_error(sqlite3_context*, const char*, int); 4459void sqlite3_result_error16(sqlite3_context*, const void*, int); 4460void sqlite3_result_error_toobig(sqlite3_context*); 4461void sqlite3_result_error_nomem(sqlite3_context*); 4462void sqlite3_result_error_code(sqlite3_context*, int); 4463void sqlite3_result_int(sqlite3_context*, int); 4464void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4465void sqlite3_result_null(sqlite3_context*); 4466void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4467void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4468void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4469void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4470void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4471void sqlite3_result_zeroblob(sqlite3_context*, int n); 4472 4473/* 4474** CAPI3REF: Define New Collating Sequences 4475** 4476** ^These functions add, remove, or modify a [collation] associated 4477** with the [database connection] specified as the first argument. 4478** 4479** ^The name of the collation is a UTF-8 string 4480** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4481** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4482** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4483** considered to be the same name. 4484** 4485** ^(The third argument (eTextRep) must be one of the constants: 4486** <ul> 4487** <li> [SQLITE_UTF8], 4488** <li> [SQLITE_UTF16LE], 4489** <li> [SQLITE_UTF16BE], 4490** <li> [SQLITE_UTF16], or 4491** <li> [SQLITE_UTF16_ALIGNED]. 4492** </ul>)^ 4493** ^The eTextRep argument determines the encoding of strings passed 4494** to the collating function callback, xCallback. 4495** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4496** force strings to be UTF16 with native byte order. 4497** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4498** on an even byte address. 4499** 4500** ^The fourth argument, pArg, is an application data pointer that is passed 4501** through as the first argument to the collating function callback. 4502** 4503** ^The fifth argument, xCallback, is a pointer to the collating function. 4504** ^Multiple collating functions can be registered using the same name but 4505** with different eTextRep parameters and SQLite will use whichever 4506** function requires the least amount of data transformation. 4507** ^If the xCallback argument is NULL then the collating function is 4508** deleted. ^When all collating functions having the same name are deleted, 4509** that collation is no longer usable. 4510** 4511** ^The collating function callback is invoked with a copy of the pArg 4512** application data pointer and with two strings in the encoding specified 4513** by the eTextRep argument. The collating function must return an 4514** integer that is negative, zero, or positive 4515** if the first string is less than, equal to, or greater than the second, 4516** respectively. A collating function must always return the same answer 4517** given the same inputs. If two or more collating functions are registered 4518** to the same collation name (using different eTextRep values) then all 4519** must give an equivalent answer when invoked with equivalent strings. 4520** The collating function must obey the following properties for all 4521** strings A, B, and C: 4522** 4523** <ol> 4524** <li> If A==B then B==A. 4525** <li> If A==B and B==C then A==C. 4526** <li> If A<B THEN B>A. 4527** <li> If A<B and B<C then A<C. 4528** </ol> 4529** 4530** If a collating function fails any of the above constraints and that 4531** collating function is registered and used, then the behavior of SQLite 4532** is undefined. 4533** 4534** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4535** with the addition that the xDestroy callback is invoked on pArg when 4536** the collating function is deleted. 4537** ^Collating functions are deleted when they are overridden by later 4538** calls to the collation creation functions or when the 4539** [database connection] is closed using [sqlite3_close()]. 4540** 4541** ^The xDestroy callback is <u>not</u> called if the 4542** sqlite3_create_collation_v2() function fails. Applications that invoke 4543** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4544** check the return code and dispose of the application data pointer 4545** themselves rather than expecting SQLite to deal with it for them. 4546** This is different from every other SQLite interface. The inconsistency 4547** is unfortunate but cannot be changed without breaking backwards 4548** compatibility. 4549** 4550** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4551*/ 4552int sqlite3_create_collation( 4553 sqlite3*, 4554 const char *zName, 4555 int eTextRep, 4556 void *pArg, 4557 int(*xCompare)(void*,int,const void*,int,const void*) 4558); 4559int sqlite3_create_collation_v2( 4560 sqlite3*, 4561 const char *zName, 4562 int eTextRep, 4563 void *pArg, 4564 int(*xCompare)(void*,int,const void*,int,const void*), 4565 void(*xDestroy)(void*) 4566); 4567int sqlite3_create_collation16( 4568 sqlite3*, 4569 const void *zName, 4570 int eTextRep, 4571 void *pArg, 4572 int(*xCompare)(void*,int,const void*,int,const void*) 4573); 4574 4575/* 4576** CAPI3REF: Collation Needed Callbacks 4577** 4578** ^To avoid having to register all collation sequences before a database 4579** can be used, a single callback function may be registered with the 4580** [database connection] to be invoked whenever an undefined collation 4581** sequence is required. 4582** 4583** ^If the function is registered using the sqlite3_collation_needed() API, 4584** then it is passed the names of undefined collation sequences as strings 4585** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4586** the names are passed as UTF-16 in machine native byte order. 4587** ^A call to either function replaces the existing collation-needed callback. 4588** 4589** ^(When the callback is invoked, the first argument passed is a copy 4590** of the second argument to sqlite3_collation_needed() or 4591** sqlite3_collation_needed16(). The second argument is the database 4592** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4593** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4594** sequence function required. The fourth parameter is the name of the 4595** required collation sequence.)^ 4596** 4597** The callback function should register the desired collation using 4598** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4599** [sqlite3_create_collation_v2()]. 4600*/ 4601int sqlite3_collation_needed( 4602 sqlite3*, 4603 void*, 4604 void(*)(void*,sqlite3*,int eTextRep,const char*) 4605); 4606int sqlite3_collation_needed16( 4607 sqlite3*, 4608 void*, 4609 void(*)(void*,sqlite3*,int eTextRep,const void*) 4610); 4611 4612#ifdef SQLITE_HAS_CODEC 4613/* 4614** Specify the key for an encrypted database. This routine should be 4615** called right after sqlite3_open(). 4616** 4617** The code to implement this API is not available in the public release 4618** of SQLite. 4619*/ 4620int sqlite3_key( 4621 sqlite3 *db, /* Database to be rekeyed */ 4622 const void *pKey, int nKey /* The key */ 4623); 4624int sqlite3_key_v2( 4625 sqlite3 *db, /* Database to be rekeyed */ 4626 const char *zDbName, /* Name of the database */ 4627 const void *pKey, int nKey /* The key */ 4628); 4629 4630/* 4631** Change the key on an open database. If the current database is not 4632** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4633** database is decrypted. 4634** 4635** The code to implement this API is not available in the public release 4636** of SQLite. 4637*/ 4638int sqlite3_rekey( 4639 sqlite3 *db, /* Database to be rekeyed */ 4640 const void *pKey, int nKey /* The new key */ 4641); 4642int sqlite3_rekey_v2( 4643 sqlite3 *db, /* Database to be rekeyed */ 4644 const char *zDbName, /* Name of the database */ 4645 const void *pKey, int nKey /* The new key */ 4646); 4647 4648/* 4649** Specify the activation key for a SEE database. Unless 4650** activated, none of the SEE routines will work. 4651*/ 4652void sqlite3_activate_see( 4653 const char *zPassPhrase /* Activation phrase */ 4654); 4655#endif 4656 4657#ifdef SQLITE_ENABLE_CEROD 4658/* 4659** Specify the activation key for a CEROD database. Unless 4660** activated, none of the CEROD routines will work. 4661*/ 4662void sqlite3_activate_cerod( 4663 const char *zPassPhrase /* Activation phrase */ 4664); 4665#endif 4666 4667/* 4668** CAPI3REF: Suspend Execution For A Short Time 4669** 4670** The sqlite3_sleep() function causes the current thread to suspend execution 4671** for at least a number of milliseconds specified in its parameter. 4672** 4673** If the operating system does not support sleep requests with 4674** millisecond time resolution, then the time will be rounded up to 4675** the nearest second. The number of milliseconds of sleep actually 4676** requested from the operating system is returned. 4677** 4678** ^SQLite implements this interface by calling the xSleep() 4679** method of the default [sqlite3_vfs] object. If the xSleep() method 4680** of the default VFS is not implemented correctly, or not implemented at 4681** all, then the behavior of sqlite3_sleep() may deviate from the description 4682** in the previous paragraphs. 4683*/ 4684int sqlite3_sleep(int); 4685 4686/* 4687** CAPI3REF: Name Of The Folder Holding Temporary Files 4688** 4689** ^(If this global variable is made to point to a string which is 4690** the name of a folder (a.k.a. directory), then all temporary files 4691** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4692** will be placed in that directory.)^ ^If this variable 4693** is a NULL pointer, then SQLite performs a search for an appropriate 4694** temporary file directory. 4695** 4696** Applications are strongly discouraged from using this global variable. 4697** It is required to set a temporary folder on Windows Runtime (WinRT). 4698** But for all other platforms, it is highly recommended that applications 4699** neither read nor write this variable. This global variable is a relic 4700** that exists for backwards compatibility of legacy applications and should 4701** be avoided in new projects. 4702** 4703** It is not safe to read or modify this variable in more than one 4704** thread at a time. It is not safe to read or modify this variable 4705** if a [database connection] is being used at the same time in a separate 4706** thread. 4707** It is intended that this variable be set once 4708** as part of process initialization and before any SQLite interface 4709** routines have been called and that this variable remain unchanged 4710** thereafter. 4711** 4712** ^The [temp_store_directory pragma] may modify this variable and cause 4713** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4714** the [temp_store_directory pragma] always assumes that any string 4715** that this variable points to is held in memory obtained from 4716** [sqlite3_malloc] and the pragma may attempt to free that memory 4717** using [sqlite3_free]. 4718** Hence, if this variable is modified directly, either it should be 4719** made NULL or made to point to memory obtained from [sqlite3_malloc] 4720** or else the use of the [temp_store_directory pragma] should be avoided. 4721** Except when requested by the [temp_store_directory pragma], SQLite 4722** does not free the memory that sqlite3_temp_directory points to. If 4723** the application wants that memory to be freed, it must do 4724** so itself, taking care to only do so after all [database connection] 4725** objects have been destroyed. 4726** 4727** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4728** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4729** features that require the use of temporary files may fail. Here is an 4730** example of how to do this using C++ with the Windows Runtime: 4731** 4732** <blockquote><pre> 4733** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4734** TemporaryFolder->Path->Data(); 4735** char zPathBuf[MAX_PATH + 1]; 4736** memset(zPathBuf, 0, sizeof(zPathBuf)); 4737** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4738** NULL, NULL); 4739** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4740** </pre></blockquote> 4741*/ 4742SQLITE_EXTERN char *sqlite3_temp_directory; 4743 4744/* 4745** CAPI3REF: Name Of The Folder Holding Database Files 4746** 4747** ^(If this global variable is made to point to a string which is 4748** the name of a folder (a.k.a. directory), then all database files 4749** specified with a relative pathname and created or accessed by 4750** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4751** to be relative to that directory.)^ ^If this variable is a NULL 4752** pointer, then SQLite assumes that all database files specified 4753** with a relative pathname are relative to the current directory 4754** for the process. Only the windows VFS makes use of this global 4755** variable; it is ignored by the unix VFS. 4756** 4757** Changing the value of this variable while a database connection is 4758** open can result in a corrupt database. 4759** 4760** It is not safe to read or modify this variable in more than one 4761** thread at a time. It is not safe to read or modify this variable 4762** if a [database connection] is being used at the same time in a separate 4763** thread. 4764** It is intended that this variable be set once 4765** as part of process initialization and before any SQLite interface 4766** routines have been called and that this variable remain unchanged 4767** thereafter. 4768** 4769** ^The [data_store_directory pragma] may modify this variable and cause 4770** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4771** the [data_store_directory pragma] always assumes that any string 4772** that this variable points to is held in memory obtained from 4773** [sqlite3_malloc] and the pragma may attempt to free that memory 4774** using [sqlite3_free]. 4775** Hence, if this variable is modified directly, either it should be 4776** made NULL or made to point to memory obtained from [sqlite3_malloc] 4777** or else the use of the [data_store_directory pragma] should be avoided. 4778*/ 4779SQLITE_EXTERN char *sqlite3_data_directory; 4780 4781/* 4782** CAPI3REF: Test For Auto-Commit Mode 4783** KEYWORDS: {autocommit mode} 4784** 4785** ^The sqlite3_get_autocommit() interface returns non-zero or 4786** zero if the given database connection is or is not in autocommit mode, 4787** respectively. ^Autocommit mode is on by default. 4788** ^Autocommit mode is disabled by a [BEGIN] statement. 4789** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4790** 4791** If certain kinds of errors occur on a statement within a multi-statement 4792** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4793** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4794** transaction might be rolled back automatically. The only way to 4795** find out whether SQLite automatically rolled back the transaction after 4796** an error is to use this function. 4797** 4798** If another thread changes the autocommit status of the database 4799** connection while this routine is running, then the return value 4800** is undefined. 4801*/ 4802int sqlite3_get_autocommit(sqlite3*); 4803 4804/* 4805** CAPI3REF: Find The Database Handle Of A Prepared Statement 4806** 4807** ^The sqlite3_db_handle interface returns the [database connection] handle 4808** to which a [prepared statement] belongs. ^The [database connection] 4809** returned by sqlite3_db_handle is the same [database connection] 4810** that was the first argument 4811** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4812** create the statement in the first place. 4813*/ 4814sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4815 4816/* 4817** CAPI3REF: Return The Filename For A Database Connection 4818** 4819** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4820** associated with database N of connection D. ^The main database file 4821** has the name "main". If there is no attached database N on the database 4822** connection D, or if database N is a temporary or in-memory database, then 4823** a NULL pointer is returned. 4824** 4825** ^The filename returned by this function is the output of the 4826** xFullPathname method of the [VFS]. ^In other words, the filename 4827** will be an absolute pathname, even if the filename used 4828** to open the database originally was a URI or relative pathname. 4829*/ 4830const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4831 4832/* 4833** CAPI3REF: Determine if a database is read-only 4834** 4835** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4836** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4837** the name of a database on connection D. 4838*/ 4839int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4840 4841/* 4842** CAPI3REF: Find the next prepared statement 4843** 4844** ^This interface returns a pointer to the next [prepared statement] after 4845** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4846** then this interface returns a pointer to the first prepared statement 4847** associated with the database connection pDb. ^If no prepared statement 4848** satisfies the conditions of this routine, it returns NULL. 4849** 4850** The [database connection] pointer D in a call to 4851** [sqlite3_next_stmt(D,S)] must refer to an open database 4852** connection and in particular must not be a NULL pointer. 4853*/ 4854sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4855 4856/* 4857** CAPI3REF: Commit And Rollback Notification Callbacks 4858** 4859** ^The sqlite3_commit_hook() interface registers a callback 4860** function to be invoked whenever a transaction is [COMMIT | committed]. 4861** ^Any callback set by a previous call to sqlite3_commit_hook() 4862** for the same database connection is overridden. 4863** ^The sqlite3_rollback_hook() interface registers a callback 4864** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4865** ^Any callback set by a previous call to sqlite3_rollback_hook() 4866** for the same database connection is overridden. 4867** ^The pArg argument is passed through to the callback. 4868** ^If the callback on a commit hook function returns non-zero, 4869** then the commit is converted into a rollback. 4870** 4871** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4872** return the P argument from the previous call of the same function 4873** on the same [database connection] D, or NULL for 4874** the first call for each function on D. 4875** 4876** The commit and rollback hook callbacks are not reentrant. 4877** The callback implementation must not do anything that will modify 4878** the database connection that invoked the callback. Any actions 4879** to modify the database connection must be deferred until after the 4880** completion of the [sqlite3_step()] call that triggered the commit 4881** or rollback hook in the first place. 4882** Note that running any other SQL statements, including SELECT statements, 4883** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4884** the database connections for the meaning of "modify" in this paragraph. 4885** 4886** ^Registering a NULL function disables the callback. 4887** 4888** ^When the commit hook callback routine returns zero, the [COMMIT] 4889** operation is allowed to continue normally. ^If the commit hook 4890** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4891** ^The rollback hook is invoked on a rollback that results from a commit 4892** hook returning non-zero, just as it would be with any other rollback. 4893** 4894** ^For the purposes of this API, a transaction is said to have been 4895** rolled back if an explicit "ROLLBACK" statement is executed, or 4896** an error or constraint causes an implicit rollback to occur. 4897** ^The rollback callback is not invoked if a transaction is 4898** automatically rolled back because the database connection is closed. 4899** 4900** See also the [sqlite3_update_hook()] interface. 4901*/ 4902void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4903void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4904 4905/* 4906** CAPI3REF: Data Change Notification Callbacks 4907** 4908** ^The sqlite3_update_hook() interface registers a callback function 4909** with the [database connection] identified by the first argument 4910** to be invoked whenever a row is updated, inserted or deleted in 4911** a rowid table. 4912** ^Any callback set by a previous call to this function 4913** for the same database connection is overridden. 4914** 4915** ^The second argument is a pointer to the function to invoke when a 4916** row is updated, inserted or deleted in a rowid table. 4917** ^The first argument to the callback is a copy of the third argument 4918** to sqlite3_update_hook(). 4919** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4920** or [SQLITE_UPDATE], depending on the operation that caused the callback 4921** to be invoked. 4922** ^The third and fourth arguments to the callback contain pointers to the 4923** database and table name containing the affected row. 4924** ^The final callback parameter is the [rowid] of the row. 4925** ^In the case of an update, this is the [rowid] after the update takes place. 4926** 4927** ^(The update hook is not invoked when internal system tables are 4928** modified (i.e. sqlite_master and sqlite_sequence).)^ 4929** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 4930** 4931** ^In the current implementation, the update hook 4932** is not invoked when duplication rows are deleted because of an 4933** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4934** invoked when rows are deleted using the [truncate optimization]. 4935** The exceptions defined in this paragraph might change in a future 4936** release of SQLite. 4937** 4938** The update hook implementation must not do anything that will modify 4939** the database connection that invoked the update hook. Any actions 4940** to modify the database connection must be deferred until after the 4941** completion of the [sqlite3_step()] call that triggered the update hook. 4942** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4943** database connections for the meaning of "modify" in this paragraph. 4944** 4945** ^The sqlite3_update_hook(D,C,P) function 4946** returns the P argument from the previous call 4947** on the same [database connection] D, or NULL for 4948** the first call on D. 4949** 4950** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4951** interfaces. 4952*/ 4953void *sqlite3_update_hook( 4954 sqlite3*, 4955 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4956 void* 4957); 4958 4959/* 4960** CAPI3REF: Enable Or Disable Shared Pager Cache 4961** 4962** ^(This routine enables or disables the sharing of the database cache 4963** and schema data structures between [database connection | connections] 4964** to the same database. Sharing is enabled if the argument is true 4965** and disabled if the argument is false.)^ 4966** 4967** ^Cache sharing is enabled and disabled for an entire process. 4968** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4969** sharing was enabled or disabled for each thread separately. 4970** 4971** ^(The cache sharing mode set by this interface effects all subsequent 4972** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4973** Existing database connections continue use the sharing mode 4974** that was in effect at the time they were opened.)^ 4975** 4976** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4977** successfully. An [error code] is returned otherwise.)^ 4978** 4979** ^Shared cache is disabled by default. But this might change in 4980** future releases of SQLite. Applications that care about shared 4981** cache setting should set it explicitly. 4982** 4983** This interface is threadsafe on processors where writing a 4984** 32-bit integer is atomic. 4985** 4986** See Also: [SQLite Shared-Cache Mode] 4987*/ 4988int sqlite3_enable_shared_cache(int); 4989 4990/* 4991** CAPI3REF: Attempt To Free Heap Memory 4992** 4993** ^The sqlite3_release_memory() interface attempts to free N bytes 4994** of heap memory by deallocating non-essential memory allocations 4995** held by the database library. Memory used to cache database 4996** pages to improve performance is an example of non-essential memory. 4997** ^sqlite3_release_memory() returns the number of bytes actually freed, 4998** which might be more or less than the amount requested. 4999** ^The sqlite3_release_memory() routine is a no-op returning zero 5000** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5001** 5002** See also: [sqlite3_db_release_memory()] 5003*/ 5004int sqlite3_release_memory(int); 5005 5006/* 5007** CAPI3REF: Free Memory Used By A Database Connection 5008** 5009** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5010** memory as possible from database connection D. Unlike the 5011** [sqlite3_release_memory()] interface, this interface is in effect even 5012** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5013** omitted. 5014** 5015** See also: [sqlite3_release_memory()] 5016*/ 5017int sqlite3_db_release_memory(sqlite3*); 5018 5019/* 5020** CAPI3REF: Impose A Limit On Heap Size 5021** 5022** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5023** soft limit on the amount of heap memory that may be allocated by SQLite. 5024** ^SQLite strives to keep heap memory utilization below the soft heap 5025** limit by reducing the number of pages held in the page cache 5026** as heap memory usages approaches the limit. 5027** ^The soft heap limit is "soft" because even though SQLite strives to stay 5028** below the limit, it will exceed the limit rather than generate 5029** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5030** is advisory only. 5031** 5032** ^The return value from sqlite3_soft_heap_limit64() is the size of 5033** the soft heap limit prior to the call, or negative in the case of an 5034** error. ^If the argument N is negative 5035** then no change is made to the soft heap limit. Hence, the current 5036** size of the soft heap limit can be determined by invoking 5037** sqlite3_soft_heap_limit64() with a negative argument. 5038** 5039** ^If the argument N is zero then the soft heap limit is disabled. 5040** 5041** ^(The soft heap limit is not enforced in the current implementation 5042** if one or more of following conditions are true: 5043** 5044** <ul> 5045** <li> The soft heap limit is set to zero. 5046** <li> Memory accounting is disabled using a combination of the 5047** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5048** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5049** <li> An alternative page cache implementation is specified using 5050** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5051** <li> The page cache allocates from its own memory pool supplied 5052** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5053** from the heap. 5054** </ul>)^ 5055** 5056** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5057** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5058** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5059** the soft heap limit is enforced on every memory allocation. Without 5060** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5061** when memory is allocated by the page cache. Testing suggests that because 5062** the page cache is the predominate memory user in SQLite, most 5063** applications will achieve adequate soft heap limit enforcement without 5064** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5065** 5066** The circumstances under which SQLite will enforce the soft heap limit may 5067** changes in future releases of SQLite. 5068*/ 5069sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5070 5071/* 5072** CAPI3REF: Deprecated Soft Heap Limit Interface 5073** DEPRECATED 5074** 5075** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5076** interface. This routine is provided for historical compatibility 5077** only. All new applications should use the 5078** [sqlite3_soft_heap_limit64()] interface rather than this one. 5079*/ 5080SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5081 5082 5083/* 5084** CAPI3REF: Extract Metadata About A Column Of A Table 5085** 5086** ^This routine returns metadata about a specific column of a specific 5087** database table accessible using the [database connection] handle 5088** passed as the first function argument. 5089** 5090** ^The column is identified by the second, third and fourth parameters to 5091** this function. ^The second parameter is either the name of the database 5092** (i.e. "main", "temp", or an attached database) containing the specified 5093** table or NULL. ^If it is NULL, then all attached databases are searched 5094** for the table using the same algorithm used by the database engine to 5095** resolve unqualified table references. 5096** 5097** ^The third and fourth parameters to this function are the table and column 5098** name of the desired column, respectively. Neither of these parameters 5099** may be NULL. 5100** 5101** ^Metadata is returned by writing to the memory locations passed as the 5th 5102** and subsequent parameters to this function. ^Any of these arguments may be 5103** NULL, in which case the corresponding element of metadata is omitted. 5104** 5105** ^(<blockquote> 5106** <table border="1"> 5107** <tr><th> Parameter <th> Output<br>Type <th> Description 5108** 5109** <tr><td> 5th <td> const char* <td> Data type 5110** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5111** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5112** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5113** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5114** </table> 5115** </blockquote>)^ 5116** 5117** ^The memory pointed to by the character pointers returned for the 5118** declaration type and collation sequence is valid only until the next 5119** call to any SQLite API function. 5120** 5121** ^If the specified table is actually a view, an [error code] is returned. 5122** 5123** ^If the specified column is "rowid", "oid" or "_rowid_" and an 5124** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5125** parameters are set for the explicitly declared column. ^(If there is no 5126** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5127** parameters are set as follows: 5128** 5129** <pre> 5130** data type: "INTEGER" 5131** collation sequence: "BINARY" 5132** not null: 0 5133** primary key: 1 5134** auto increment: 0 5135** </pre>)^ 5136** 5137** ^(This function may load one or more schemas from database files. If an 5138** error occurs during this process, or if the requested table or column 5139** cannot be found, an [error code] is returned and an error message left 5140** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5141** 5142** ^This API is only available if the library was compiled with the 5143** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5144*/ 5145int sqlite3_table_column_metadata( 5146 sqlite3 *db, /* Connection handle */ 5147 const char *zDbName, /* Database name or NULL */ 5148 const char *zTableName, /* Table name */ 5149 const char *zColumnName, /* Column name */ 5150 char const **pzDataType, /* OUTPUT: Declared data type */ 5151 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5152 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5153 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5154 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5155); 5156 5157/* 5158** CAPI3REF: Load An Extension 5159** 5160** ^This interface loads an SQLite extension library from the named file. 5161** 5162** ^The sqlite3_load_extension() interface attempts to load an 5163** [SQLite extension] library contained in the file zFile. If 5164** the file cannot be loaded directly, attempts are made to load 5165** with various operating-system specific extensions added. 5166** So for example, if "samplelib" cannot be loaded, then names like 5167** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5168** be tried also. 5169** 5170** ^The entry point is zProc. 5171** ^(zProc may be 0, in which case SQLite will try to come up with an 5172** entry point name on its own. It first tries "sqlite3_extension_init". 5173** If that does not work, it constructs a name "sqlite3_X_init" where the 5174** X is consists of the lower-case equivalent of all ASCII alphabetic 5175** characters in the filename from the last "/" to the first following 5176** "." and omitting any initial "lib".)^ 5177** ^The sqlite3_load_extension() interface returns 5178** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5179** ^If an error occurs and pzErrMsg is not 0, then the 5180** [sqlite3_load_extension()] interface shall attempt to 5181** fill *pzErrMsg with error message text stored in memory 5182** obtained from [sqlite3_malloc()]. The calling function 5183** should free this memory by calling [sqlite3_free()]. 5184** 5185** ^Extension loading must be enabled using 5186** [sqlite3_enable_load_extension()] prior to calling this API, 5187** otherwise an error will be returned. 5188** 5189** See also the [load_extension() SQL function]. 5190*/ 5191int sqlite3_load_extension( 5192 sqlite3 *db, /* Load the extension into this database connection */ 5193 const char *zFile, /* Name of the shared library containing extension */ 5194 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5195 char **pzErrMsg /* Put error message here if not 0 */ 5196); 5197 5198/* 5199** CAPI3REF: Enable Or Disable Extension Loading 5200** 5201** ^So as not to open security holes in older applications that are 5202** unprepared to deal with [extension loading], and as a means of disabling 5203** [extension loading] while evaluating user-entered SQL, the following API 5204** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5205** 5206** ^Extension loading is off by default. 5207** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5208** to turn extension loading on and call it with onoff==0 to turn 5209** it back off again. 5210*/ 5211int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5212 5213/* 5214** CAPI3REF: Automatically Load Statically Linked Extensions 5215** 5216** ^This interface causes the xEntryPoint() function to be invoked for 5217** each new [database connection] that is created. The idea here is that 5218** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5219** that is to be automatically loaded into all new database connections. 5220** 5221** ^(Even though the function prototype shows that xEntryPoint() takes 5222** no arguments and returns void, SQLite invokes xEntryPoint() with three 5223** arguments and expects and integer result as if the signature of the 5224** entry point where as follows: 5225** 5226** <blockquote><pre> 5227** int xEntryPoint( 5228** sqlite3 *db, 5229** const char **pzErrMsg, 5230** const struct sqlite3_api_routines *pThunk 5231** ); 5232** </pre></blockquote>)^ 5233** 5234** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5235** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5236** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5237** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5238** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5239** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5240** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5241** 5242** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5243** on the list of automatic extensions is a harmless no-op. ^No entry point 5244** will be called more than once for each database connection that is opened. 5245** 5246** See also: [sqlite3_reset_auto_extension()] 5247** and [sqlite3_cancel_auto_extension()] 5248*/ 5249int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5250 5251/* 5252** CAPI3REF: Cancel Automatic Extension Loading 5253** 5254** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5255** initialization routine X that was registered using a prior call to 5256** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5257** routine returns 1 if initialization routine X was successfully 5258** unregistered and it returns 0 if X was not on the list of initialization 5259** routines. 5260*/ 5261int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5262 5263/* 5264** CAPI3REF: Reset Automatic Extension Loading 5265** 5266** ^This interface disables all automatic extensions previously 5267** registered using [sqlite3_auto_extension()]. 5268*/ 5269void sqlite3_reset_auto_extension(void); 5270 5271/* 5272** The interface to the virtual-table mechanism is currently considered 5273** to be experimental. The interface might change in incompatible ways. 5274** If this is a problem for you, do not use the interface at this time. 5275** 5276** When the virtual-table mechanism stabilizes, we will declare the 5277** interface fixed, support it indefinitely, and remove this comment. 5278*/ 5279 5280/* 5281** Structures used by the virtual table interface 5282*/ 5283typedef struct sqlite3_vtab sqlite3_vtab; 5284typedef struct sqlite3_index_info sqlite3_index_info; 5285typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5286typedef struct sqlite3_module sqlite3_module; 5287 5288/* 5289** CAPI3REF: Virtual Table Object 5290** KEYWORDS: sqlite3_module {virtual table module} 5291** 5292** This structure, sometimes called a "virtual table module", 5293** defines the implementation of a [virtual tables]. 5294** This structure consists mostly of methods for the module. 5295** 5296** ^A virtual table module is created by filling in a persistent 5297** instance of this structure and passing a pointer to that instance 5298** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5299** ^The registration remains valid until it is replaced by a different 5300** module or until the [database connection] closes. The content 5301** of this structure must not change while it is registered with 5302** any database connection. 5303*/ 5304struct sqlite3_module { 5305 int iVersion; 5306 int (*xCreate)(sqlite3*, void *pAux, 5307 int argc, const char *const*argv, 5308 sqlite3_vtab **ppVTab, char**); 5309 int (*xConnect)(sqlite3*, void *pAux, 5310 int argc, const char *const*argv, 5311 sqlite3_vtab **ppVTab, char**); 5312 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5313 int (*xDisconnect)(sqlite3_vtab *pVTab); 5314 int (*xDestroy)(sqlite3_vtab *pVTab); 5315 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5316 int (*xClose)(sqlite3_vtab_cursor*); 5317 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5318 int argc, sqlite3_value **argv); 5319 int (*xNext)(sqlite3_vtab_cursor*); 5320 int (*xEof)(sqlite3_vtab_cursor*); 5321 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5322 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5323 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5324 int (*xBegin)(sqlite3_vtab *pVTab); 5325 int (*xSync)(sqlite3_vtab *pVTab); 5326 int (*xCommit)(sqlite3_vtab *pVTab); 5327 int (*xRollback)(sqlite3_vtab *pVTab); 5328 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5329 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5330 void **ppArg); 5331 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5332 /* The methods above are in version 1 of the sqlite_module object. Those 5333 ** below are for version 2 and greater. */ 5334 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5335 int (*xRelease)(sqlite3_vtab *pVTab, int); 5336 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5337}; 5338 5339/* 5340** CAPI3REF: Virtual Table Indexing Information 5341** KEYWORDS: sqlite3_index_info 5342** 5343** The sqlite3_index_info structure and its substructures is used as part 5344** of the [virtual table] interface to 5345** pass information into and receive the reply from the [xBestIndex] 5346** method of a [virtual table module]. The fields under **Inputs** are the 5347** inputs to xBestIndex and are read-only. xBestIndex inserts its 5348** results into the **Outputs** fields. 5349** 5350** ^(The aConstraint[] array records WHERE clause constraints of the form: 5351** 5352** <blockquote>column OP expr</blockquote> 5353** 5354** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5355** stored in aConstraint[].op using one of the 5356** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5357** ^(The index of the column is stored in 5358** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5359** expr on the right-hand side can be evaluated (and thus the constraint 5360** is usable) and false if it cannot.)^ 5361** 5362** ^The optimizer automatically inverts terms of the form "expr OP column" 5363** and makes other simplifications to the WHERE clause in an attempt to 5364** get as many WHERE clause terms into the form shown above as possible. 5365** ^The aConstraint[] array only reports WHERE clause terms that are 5366** relevant to the particular virtual table being queried. 5367** 5368** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5369** ^Each term of aOrderBy records a column of the ORDER BY clause. 5370** 5371** The [xBestIndex] method must fill aConstraintUsage[] with information 5372** about what parameters to pass to xFilter. ^If argvIndex>0 then 5373** the right-hand side of the corresponding aConstraint[] is evaluated 5374** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5375** is true, then the constraint is assumed to be fully handled by the 5376** virtual table and is not checked again by SQLite.)^ 5377** 5378** ^The idxNum and idxPtr values are recorded and passed into the 5379** [xFilter] method. 5380** ^[sqlite3_free()] is used to free idxPtr if and only if 5381** needToFreeIdxPtr is true. 5382** 5383** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5384** the correct order to satisfy the ORDER BY clause so that no separate 5385** sorting step is required. 5386** 5387** ^The estimatedCost value is an estimate of the cost of a particular 5388** strategy. A cost of N indicates that the cost of the strategy is similar 5389** to a linear scan of an SQLite table with N rows. A cost of log(N) 5390** indicates that the expense of the operation is similar to that of a 5391** binary search on a unique indexed field of an SQLite table with N rows. 5392** 5393** ^The estimatedRows value is an estimate of the number of rows that 5394** will be returned by the strategy. 5395** 5396** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5397** structure for SQLite version 3.8.2. If a virtual table extension is 5398** used with an SQLite version earlier than 3.8.2, the results of attempting 5399** to read or write the estimatedRows field are undefined (but are likely 5400** to included crashing the application). The estimatedRows field should 5401** therefore only be used if [sqlite3_libversion_number()] returns a 5402** value greater than or equal to 3008002. 5403*/ 5404struct sqlite3_index_info { 5405 /* Inputs */ 5406 int nConstraint; /* Number of entries in aConstraint */ 5407 struct sqlite3_index_constraint { 5408 int iColumn; /* Column on left-hand side of constraint */ 5409 unsigned char op; /* Constraint operator */ 5410 unsigned char usable; /* True if this constraint is usable */ 5411 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5412 } *aConstraint; /* Table of WHERE clause constraints */ 5413 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5414 struct sqlite3_index_orderby { 5415 int iColumn; /* Column number */ 5416 unsigned char desc; /* True for DESC. False for ASC. */ 5417 } *aOrderBy; /* The ORDER BY clause */ 5418 /* Outputs */ 5419 struct sqlite3_index_constraint_usage { 5420 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5421 unsigned char omit; /* Do not code a test for this constraint */ 5422 } *aConstraintUsage; 5423 int idxNum; /* Number used to identify the index */ 5424 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5425 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5426 int orderByConsumed; /* True if output is already ordered */ 5427 double estimatedCost; /* Estimated cost of using this index */ 5428 /* Fields below are only available in SQLite 3.8.2 and later */ 5429 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5430}; 5431 5432/* 5433** CAPI3REF: Virtual Table Constraint Operator Codes 5434** 5435** These macros defined the allowed values for the 5436** [sqlite3_index_info].aConstraint[].op field. Each value represents 5437** an operator that is part of a constraint term in the wHERE clause of 5438** a query that uses a [virtual table]. 5439*/ 5440#define SQLITE_INDEX_CONSTRAINT_EQ 2 5441#define SQLITE_INDEX_CONSTRAINT_GT 4 5442#define SQLITE_INDEX_CONSTRAINT_LE 8 5443#define SQLITE_INDEX_CONSTRAINT_LT 16 5444#define SQLITE_INDEX_CONSTRAINT_GE 32 5445#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5446 5447/* 5448** CAPI3REF: Register A Virtual Table Implementation 5449** 5450** ^These routines are used to register a new [virtual table module] name. 5451** ^Module names must be registered before 5452** creating a new [virtual table] using the module and before using a 5453** preexisting [virtual table] for the module. 5454** 5455** ^The module name is registered on the [database connection] specified 5456** by the first parameter. ^The name of the module is given by the 5457** second parameter. ^The third parameter is a pointer to 5458** the implementation of the [virtual table module]. ^The fourth 5459** parameter is an arbitrary client data pointer that is passed through 5460** into the [xCreate] and [xConnect] methods of the virtual table module 5461** when a new virtual table is be being created or reinitialized. 5462** 5463** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5464** is a pointer to a destructor for the pClientData. ^SQLite will 5465** invoke the destructor function (if it is not NULL) when SQLite 5466** no longer needs the pClientData pointer. ^The destructor will also 5467** be invoked if the call to sqlite3_create_module_v2() fails. 5468** ^The sqlite3_create_module() 5469** interface is equivalent to sqlite3_create_module_v2() with a NULL 5470** destructor. 5471*/ 5472int sqlite3_create_module( 5473 sqlite3 *db, /* SQLite connection to register module with */ 5474 const char *zName, /* Name of the module */ 5475 const sqlite3_module *p, /* Methods for the module */ 5476 void *pClientData /* Client data for xCreate/xConnect */ 5477); 5478int sqlite3_create_module_v2( 5479 sqlite3 *db, /* SQLite connection to register module with */ 5480 const char *zName, /* Name of the module */ 5481 const sqlite3_module *p, /* Methods for the module */ 5482 void *pClientData, /* Client data for xCreate/xConnect */ 5483 void(*xDestroy)(void*) /* Module destructor function */ 5484); 5485 5486/* 5487** CAPI3REF: Virtual Table Instance Object 5488** KEYWORDS: sqlite3_vtab 5489** 5490** Every [virtual table module] implementation uses a subclass 5491** of this object to describe a particular instance 5492** of the [virtual table]. Each subclass will 5493** be tailored to the specific needs of the module implementation. 5494** The purpose of this superclass is to define certain fields that are 5495** common to all module implementations. 5496** 5497** ^Virtual tables methods can set an error message by assigning a 5498** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5499** take care that any prior string is freed by a call to [sqlite3_free()] 5500** prior to assigning a new string to zErrMsg. ^After the error message 5501** is delivered up to the client application, the string will be automatically 5502** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5503*/ 5504struct sqlite3_vtab { 5505 const sqlite3_module *pModule; /* The module for this virtual table */ 5506 int nRef; /* NO LONGER USED */ 5507 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5508 /* Virtual table implementations will typically add additional fields */ 5509}; 5510 5511/* 5512** CAPI3REF: Virtual Table Cursor Object 5513** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5514** 5515** Every [virtual table module] implementation uses a subclass of the 5516** following structure to describe cursors that point into the 5517** [virtual table] and are used 5518** to loop through the virtual table. Cursors are created using the 5519** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5520** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5521** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5522** of the module. Each module implementation will define 5523** the content of a cursor structure to suit its own needs. 5524** 5525** This superclass exists in order to define fields of the cursor that 5526** are common to all implementations. 5527*/ 5528struct sqlite3_vtab_cursor { 5529 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5530 /* Virtual table implementations will typically add additional fields */ 5531}; 5532 5533/* 5534** CAPI3REF: Declare The Schema Of A Virtual Table 5535** 5536** ^The [xCreate] and [xConnect] methods of a 5537** [virtual table module] call this interface 5538** to declare the format (the names and datatypes of the columns) of 5539** the virtual tables they implement. 5540*/ 5541int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5542 5543/* 5544** CAPI3REF: Overload A Function For A Virtual Table 5545** 5546** ^(Virtual tables can provide alternative implementations of functions 5547** using the [xFindFunction] method of the [virtual table module]. 5548** But global versions of those functions 5549** must exist in order to be overloaded.)^ 5550** 5551** ^(This API makes sure a global version of a function with a particular 5552** name and number of parameters exists. If no such function exists 5553** before this API is called, a new function is created.)^ ^The implementation 5554** of the new function always causes an exception to be thrown. So 5555** the new function is not good for anything by itself. Its only 5556** purpose is to be a placeholder function that can be overloaded 5557** by a [virtual table]. 5558*/ 5559int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5560 5561/* 5562** The interface to the virtual-table mechanism defined above (back up 5563** to a comment remarkably similar to this one) is currently considered 5564** to be experimental. The interface might change in incompatible ways. 5565** If this is a problem for you, do not use the interface at this time. 5566** 5567** When the virtual-table mechanism stabilizes, we will declare the 5568** interface fixed, support it indefinitely, and remove this comment. 5569*/ 5570 5571/* 5572** CAPI3REF: A Handle To An Open BLOB 5573** KEYWORDS: {BLOB handle} {BLOB handles} 5574** 5575** An instance of this object represents an open BLOB on which 5576** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5577** ^Objects of this type are created by [sqlite3_blob_open()] 5578** and destroyed by [sqlite3_blob_close()]. 5579** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5580** can be used to read or write small subsections of the BLOB. 5581** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5582*/ 5583typedef struct sqlite3_blob sqlite3_blob; 5584 5585/* 5586** CAPI3REF: Open A BLOB For Incremental I/O 5587** 5588** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5589** in row iRow, column zColumn, table zTable in database zDb; 5590** in other words, the same BLOB that would be selected by: 5591** 5592** <pre> 5593** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5594** </pre>)^ 5595** 5596** ^If the flags parameter is non-zero, then the BLOB is opened for read 5597** and write access. ^If it is zero, the BLOB is opened for read access. 5598** ^It is not possible to open a column that is part of an index or primary 5599** key for writing. ^If [foreign key constraints] are enabled, it is 5600** not possible to open a column that is part of a [child key] for writing. 5601** 5602** ^Note that the database name is not the filename that contains 5603** the database but rather the symbolic name of the database that 5604** appears after the AS keyword when the database is connected using [ATTACH]. 5605** ^For the main database file, the database name is "main". 5606** ^For TEMP tables, the database name is "temp". 5607** 5608** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5609** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5610** to be a null pointer.)^ 5611** ^This function sets the [database connection] error code and message 5612** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5613** functions. ^Note that the *ppBlob variable is always initialized in a 5614** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5615** regardless of the success or failure of this routine. 5616** 5617** ^(If the row that a BLOB handle points to is modified by an 5618** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5619** then the BLOB handle is marked as "expired". 5620** This is true if any column of the row is changed, even a column 5621** other than the one the BLOB handle is open on.)^ 5622** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5623** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5624** ^(Changes written into a BLOB prior to the BLOB expiring are not 5625** rolled back by the expiration of the BLOB. Such changes will eventually 5626** commit if the transaction continues to completion.)^ 5627** 5628** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5629** the opened blob. ^The size of a blob may not be changed by this 5630** interface. Use the [UPDATE] SQL command to change the size of a 5631** blob. 5632** 5633** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] 5634** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. 5635** 5636** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5637** and the built-in [zeroblob] SQL function can be used, if desired, 5638** to create an empty, zero-filled blob in which to read or write using 5639** this interface. 5640** 5641** To avoid a resource leak, every open [BLOB handle] should eventually 5642** be released by a call to [sqlite3_blob_close()]. 5643*/ 5644int sqlite3_blob_open( 5645 sqlite3*, 5646 const char *zDb, 5647 const char *zTable, 5648 const char *zColumn, 5649 sqlite3_int64 iRow, 5650 int flags, 5651 sqlite3_blob **ppBlob 5652); 5653 5654/* 5655** CAPI3REF: Move a BLOB Handle to a New Row 5656** 5657** ^This function is used to move an existing blob handle so that it points 5658** to a different row of the same database table. ^The new row is identified 5659** by the rowid value passed as the second argument. Only the row can be 5660** changed. ^The database, table and column on which the blob handle is open 5661** remain the same. Moving an existing blob handle to a new row can be 5662** faster than closing the existing handle and opening a new one. 5663** 5664** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5665** it must exist and there must be either a blob or text value stored in 5666** the nominated column.)^ ^If the new row is not present in the table, or if 5667** it does not contain a blob or text value, or if another error occurs, an 5668** SQLite error code is returned and the blob handle is considered aborted. 5669** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5670** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5671** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5672** always returns zero. 5673** 5674** ^This function sets the database handle error code and message. 5675*/ 5676SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5677 5678/* 5679** CAPI3REF: Close A BLOB Handle 5680** 5681** ^Closes an open [BLOB handle]. 5682** 5683** ^Closing a BLOB shall cause the current transaction to commit 5684** if there are no other BLOBs, no pending prepared statements, and the 5685** database connection is in [autocommit mode]. 5686** ^If any writes were made to the BLOB, they might be held in cache 5687** until the close operation if they will fit. 5688** 5689** ^(Closing the BLOB often forces the changes 5690** out to disk and so if any I/O errors occur, they will likely occur 5691** at the time when the BLOB is closed. Any errors that occur during 5692** closing are reported as a non-zero return value.)^ 5693** 5694** ^(The BLOB is closed unconditionally. Even if this routine returns 5695** an error code, the BLOB is still closed.)^ 5696** 5697** ^Calling this routine with a null pointer (such as would be returned 5698** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5699*/ 5700int sqlite3_blob_close(sqlite3_blob *); 5701 5702/* 5703** CAPI3REF: Return The Size Of An Open BLOB 5704** 5705** ^Returns the size in bytes of the BLOB accessible via the 5706** successfully opened [BLOB handle] in its only argument. ^The 5707** incremental blob I/O routines can only read or overwriting existing 5708** blob content; they cannot change the size of a blob. 5709** 5710** This routine only works on a [BLOB handle] which has been created 5711** by a prior successful call to [sqlite3_blob_open()] and which has not 5712** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5713** to this routine results in undefined and probably undesirable behavior. 5714*/ 5715int sqlite3_blob_bytes(sqlite3_blob *); 5716 5717/* 5718** CAPI3REF: Read Data From A BLOB Incrementally 5719** 5720** ^(This function is used to read data from an open [BLOB handle] into a 5721** caller-supplied buffer. N bytes of data are copied into buffer Z 5722** from the open BLOB, starting at offset iOffset.)^ 5723** 5724** ^If offset iOffset is less than N bytes from the end of the BLOB, 5725** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5726** less than zero, [SQLITE_ERROR] is returned and no data is read. 5727** ^The size of the blob (and hence the maximum value of N+iOffset) 5728** can be determined using the [sqlite3_blob_bytes()] interface. 5729** 5730** ^An attempt to read from an expired [BLOB handle] fails with an 5731** error code of [SQLITE_ABORT]. 5732** 5733** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5734** Otherwise, an [error code] or an [extended error code] is returned.)^ 5735** 5736** This routine only works on a [BLOB handle] which has been created 5737** by a prior successful call to [sqlite3_blob_open()] and which has not 5738** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5739** to this routine results in undefined and probably undesirable behavior. 5740** 5741** See also: [sqlite3_blob_write()]. 5742*/ 5743int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5744 5745/* 5746** CAPI3REF: Write Data Into A BLOB Incrementally 5747** 5748** ^This function is used to write data into an open [BLOB handle] from a 5749** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5750** into the open BLOB, starting at offset iOffset. 5751** 5752** ^If the [BLOB handle] passed as the first argument was not opened for 5753** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5754** this function returns [SQLITE_READONLY]. 5755** 5756** ^This function may only modify the contents of the BLOB; it is 5757** not possible to increase the size of a BLOB using this API. 5758** ^If offset iOffset is less than N bytes from the end of the BLOB, 5759** [SQLITE_ERROR] is returned and no data is written. ^If N is 5760** less than zero [SQLITE_ERROR] is returned and no data is written. 5761** The size of the BLOB (and hence the maximum value of N+iOffset) 5762** can be determined using the [sqlite3_blob_bytes()] interface. 5763** 5764** ^An attempt to write to an expired [BLOB handle] fails with an 5765** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5766** before the [BLOB handle] expired are not rolled back by the 5767** expiration of the handle, though of course those changes might 5768** have been overwritten by the statement that expired the BLOB handle 5769** or by other independent statements. 5770** 5771** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5772** Otherwise, an [error code] or an [extended error code] is returned.)^ 5773** 5774** This routine only works on a [BLOB handle] which has been created 5775** by a prior successful call to [sqlite3_blob_open()] and which has not 5776** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5777** to this routine results in undefined and probably undesirable behavior. 5778** 5779** See also: [sqlite3_blob_read()]. 5780*/ 5781int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5782 5783/* 5784** CAPI3REF: Virtual File System Objects 5785** 5786** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5787** that SQLite uses to interact 5788** with the underlying operating system. Most SQLite builds come with a 5789** single default VFS that is appropriate for the host computer. 5790** New VFSes can be registered and existing VFSes can be unregistered. 5791** The following interfaces are provided. 5792** 5793** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5794** ^Names are case sensitive. 5795** ^Names are zero-terminated UTF-8 strings. 5796** ^If there is no match, a NULL pointer is returned. 5797** ^If zVfsName is NULL then the default VFS is returned. 5798** 5799** ^New VFSes are registered with sqlite3_vfs_register(). 5800** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5801** ^The same VFS can be registered multiple times without injury. 5802** ^To make an existing VFS into the default VFS, register it again 5803** with the makeDflt flag set. If two different VFSes with the 5804** same name are registered, the behavior is undefined. If a 5805** VFS is registered with a name that is NULL or an empty string, 5806** then the behavior is undefined. 5807** 5808** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5809** ^(If the default VFS is unregistered, another VFS is chosen as 5810** the default. The choice for the new VFS is arbitrary.)^ 5811*/ 5812sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5813int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5814int sqlite3_vfs_unregister(sqlite3_vfs*); 5815 5816/* 5817** CAPI3REF: Mutexes 5818** 5819** The SQLite core uses these routines for thread 5820** synchronization. Though they are intended for internal 5821** use by SQLite, code that links against SQLite is 5822** permitted to use any of these routines. 5823** 5824** The SQLite source code contains multiple implementations 5825** of these mutex routines. An appropriate implementation 5826** is selected automatically at compile-time. ^(The following 5827** implementations are available in the SQLite core: 5828** 5829** <ul> 5830** <li> SQLITE_MUTEX_PTHREADS 5831** <li> SQLITE_MUTEX_W32 5832** <li> SQLITE_MUTEX_NOOP 5833** </ul>)^ 5834** 5835** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5836** that does no real locking and is appropriate for use in 5837** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5838** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5839** and Windows. 5840** 5841** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5842** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5843** implementation is included with the library. In this case the 5844** application must supply a custom mutex implementation using the 5845** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5846** before calling sqlite3_initialize() or any other public sqlite3_ 5847** function that calls sqlite3_initialize().)^ 5848** 5849** ^The sqlite3_mutex_alloc() routine allocates a new 5850** mutex and returns a pointer to it. ^If it returns NULL 5851** that means that a mutex could not be allocated. ^SQLite 5852** will unwind its stack and return an error. ^(The argument 5853** to sqlite3_mutex_alloc() is one of these integer constants: 5854** 5855** <ul> 5856** <li> SQLITE_MUTEX_FAST 5857** <li> SQLITE_MUTEX_RECURSIVE 5858** <li> SQLITE_MUTEX_STATIC_MASTER 5859** <li> SQLITE_MUTEX_STATIC_MEM 5860** <li> SQLITE_MUTEX_STATIC_OPEN 5861** <li> SQLITE_MUTEX_STATIC_PRNG 5862** <li> SQLITE_MUTEX_STATIC_LRU 5863** <li> SQLITE_MUTEX_STATIC_PMEM 5864** <li> SQLITE_MUTEX_STATIC_APP1 5865** <li> SQLITE_MUTEX_STATIC_APP2 5866** </ul>)^ 5867** 5868** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5869** cause sqlite3_mutex_alloc() to create 5870** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5871** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5872** The mutex implementation does not need to make a distinction 5873** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5874** not want to. ^SQLite will only request a recursive mutex in 5875** cases where it really needs one. ^If a faster non-recursive mutex 5876** implementation is available on the host platform, the mutex subsystem 5877** might return such a mutex in response to SQLITE_MUTEX_FAST. 5878** 5879** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5880** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5881** a pointer to a static preexisting mutex. ^Six static mutexes are 5882** used by the current version of SQLite. Future versions of SQLite 5883** may add additional static mutexes. Static mutexes are for internal 5884** use by SQLite only. Applications that use SQLite mutexes should 5885** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5886** SQLITE_MUTEX_RECURSIVE. 5887** 5888** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5889** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5890** returns a different mutex on every call. ^But for the static 5891** mutex types, the same mutex is returned on every call that has 5892** the same type number. 5893** 5894** ^The sqlite3_mutex_free() routine deallocates a previously 5895** allocated dynamic mutex. ^SQLite is careful to deallocate every 5896** dynamic mutex that it allocates. The dynamic mutexes must not be in 5897** use when they are deallocated. Attempting to deallocate a static 5898** mutex results in undefined behavior. ^SQLite never deallocates 5899** a static mutex. 5900** 5901** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5902** to enter a mutex. ^If another thread is already within the mutex, 5903** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5904** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5905** upon successful entry. ^(Mutexes created using 5906** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5907** In such cases the, 5908** mutex must be exited an equal number of times before another thread 5909** can enter.)^ ^(If the same thread tries to enter any other 5910** kind of mutex more than once, the behavior is undefined. 5911** SQLite will never exhibit 5912** such behavior in its own use of mutexes.)^ 5913** 5914** ^(Some systems (for example, Windows 95) do not support the operation 5915** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5916** will always return SQLITE_BUSY. The SQLite core only ever uses 5917** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5918** 5919** ^The sqlite3_mutex_leave() routine exits a mutex that was 5920** previously entered by the same thread. ^(The behavior 5921** is undefined if the mutex is not currently entered by the 5922** calling thread or is not currently allocated. SQLite will 5923** never do either.)^ 5924** 5925** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5926** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5927** behave as no-ops. 5928** 5929** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5930*/ 5931sqlite3_mutex *sqlite3_mutex_alloc(int); 5932void sqlite3_mutex_free(sqlite3_mutex*); 5933void sqlite3_mutex_enter(sqlite3_mutex*); 5934int sqlite3_mutex_try(sqlite3_mutex*); 5935void sqlite3_mutex_leave(sqlite3_mutex*); 5936 5937/* 5938** CAPI3REF: Mutex Methods Object 5939** 5940** An instance of this structure defines the low-level routines 5941** used to allocate and use mutexes. 5942** 5943** Usually, the default mutex implementations provided by SQLite are 5944** sufficient, however the user has the option of substituting a custom 5945** implementation for specialized deployments or systems for which SQLite 5946** does not provide a suitable implementation. In this case, the user 5947** creates and populates an instance of this structure to pass 5948** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5949** Additionally, an instance of this structure can be used as an 5950** output variable when querying the system for the current mutex 5951** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5952** 5953** ^The xMutexInit method defined by this structure is invoked as 5954** part of system initialization by the sqlite3_initialize() function. 5955** ^The xMutexInit routine is called by SQLite exactly once for each 5956** effective call to [sqlite3_initialize()]. 5957** 5958** ^The xMutexEnd method defined by this structure is invoked as 5959** part of system shutdown by the sqlite3_shutdown() function. The 5960** implementation of this method is expected to release all outstanding 5961** resources obtained by the mutex methods implementation, especially 5962** those obtained by the xMutexInit method. ^The xMutexEnd() 5963** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5964** 5965** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5966** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5967** xMutexNotheld) implement the following interfaces (respectively): 5968** 5969** <ul> 5970** <li> [sqlite3_mutex_alloc()] </li> 5971** <li> [sqlite3_mutex_free()] </li> 5972** <li> [sqlite3_mutex_enter()] </li> 5973** <li> [sqlite3_mutex_try()] </li> 5974** <li> [sqlite3_mutex_leave()] </li> 5975** <li> [sqlite3_mutex_held()] </li> 5976** <li> [sqlite3_mutex_notheld()] </li> 5977** </ul>)^ 5978** 5979** The only difference is that the public sqlite3_XXX functions enumerated 5980** above silently ignore any invocations that pass a NULL pointer instead 5981** of a valid mutex handle. The implementations of the methods defined 5982** by this structure are not required to handle this case, the results 5983** of passing a NULL pointer instead of a valid mutex handle are undefined 5984** (i.e. it is acceptable to provide an implementation that segfaults if 5985** it is passed a NULL pointer). 5986** 5987** The xMutexInit() method must be threadsafe. ^It must be harmless to 5988** invoke xMutexInit() multiple times within the same process and without 5989** intervening calls to xMutexEnd(). Second and subsequent calls to 5990** xMutexInit() must be no-ops. 5991** 5992** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5993** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5994** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5995** memory allocation for a fast or recursive mutex. 5996** 5997** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5998** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5999** If xMutexInit fails in any way, it is expected to clean up after itself 6000** prior to returning. 6001*/ 6002typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6003struct sqlite3_mutex_methods { 6004 int (*xMutexInit)(void); 6005 int (*xMutexEnd)(void); 6006 sqlite3_mutex *(*xMutexAlloc)(int); 6007 void (*xMutexFree)(sqlite3_mutex *); 6008 void (*xMutexEnter)(sqlite3_mutex *); 6009 int (*xMutexTry)(sqlite3_mutex *); 6010 void (*xMutexLeave)(sqlite3_mutex *); 6011 int (*xMutexHeld)(sqlite3_mutex *); 6012 int (*xMutexNotheld)(sqlite3_mutex *); 6013}; 6014 6015/* 6016** CAPI3REF: Mutex Verification Routines 6017** 6018** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6019** are intended for use inside assert() statements. ^The SQLite core 6020** never uses these routines except inside an assert() and applications 6021** are advised to follow the lead of the core. ^The SQLite core only 6022** provides implementations for these routines when it is compiled 6023** with the SQLITE_DEBUG flag. ^External mutex implementations 6024** are only required to provide these routines if SQLITE_DEBUG is 6025** defined and if NDEBUG is not defined. 6026** 6027** ^These routines should return true if the mutex in their argument 6028** is held or not held, respectively, by the calling thread. 6029** 6030** ^The implementation is not required to provide versions of these 6031** routines that actually work. If the implementation does not provide working 6032** versions of these routines, it should at least provide stubs that always 6033** return true so that one does not get spurious assertion failures. 6034** 6035** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 6036** the routine should return 1. This seems counter-intuitive since 6037** clearly the mutex cannot be held if it does not exist. But 6038** the reason the mutex does not exist is because the build is not 6039** using mutexes. And we do not want the assert() containing the 6040** call to sqlite3_mutex_held() to fail, so a non-zero return is 6041** the appropriate thing to do. ^The sqlite3_mutex_notheld() 6042** interface should also return 1 when given a NULL pointer. 6043*/ 6044#ifndef NDEBUG 6045int sqlite3_mutex_held(sqlite3_mutex*); 6046int sqlite3_mutex_notheld(sqlite3_mutex*); 6047#endif 6048 6049/* 6050** CAPI3REF: Mutex Types 6051** 6052** The [sqlite3_mutex_alloc()] interface takes a single argument 6053** which is one of these integer constants. 6054** 6055** The set of static mutexes may change from one SQLite release to the 6056** next. Applications that override the built-in mutex logic must be 6057** prepared to accommodate additional static mutexes. 6058*/ 6059#define SQLITE_MUTEX_FAST 0 6060#define SQLITE_MUTEX_RECURSIVE 1 6061#define SQLITE_MUTEX_STATIC_MASTER 2 6062#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6063#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6064#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6065#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6066#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6067#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6068#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6069#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6070#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6071#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6072 6073/* 6074** CAPI3REF: Retrieve the mutex for a database connection 6075** 6076** ^This interface returns a pointer the [sqlite3_mutex] object that 6077** serializes access to the [database connection] given in the argument 6078** when the [threading mode] is Serialized. 6079** ^If the [threading mode] is Single-thread or Multi-thread then this 6080** routine returns a NULL pointer. 6081*/ 6082sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6083 6084/* 6085** CAPI3REF: Low-Level Control Of Database Files 6086** 6087** ^The [sqlite3_file_control()] interface makes a direct call to the 6088** xFileControl method for the [sqlite3_io_methods] object associated 6089** with a particular database identified by the second argument. ^The 6090** name of the database is "main" for the main database or "temp" for the 6091** TEMP database, or the name that appears after the AS keyword for 6092** databases that are added using the [ATTACH] SQL command. 6093** ^A NULL pointer can be used in place of "main" to refer to the 6094** main database file. 6095** ^The third and fourth parameters to this routine 6096** are passed directly through to the second and third parameters of 6097** the xFileControl method. ^The return value of the xFileControl 6098** method becomes the return value of this routine. 6099** 6100** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6101** a pointer to the underlying [sqlite3_file] object to be written into 6102** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6103** case is a short-circuit path which does not actually invoke the 6104** underlying sqlite3_io_methods.xFileControl method. 6105** 6106** ^If the second parameter (zDbName) does not match the name of any 6107** open database file, then SQLITE_ERROR is returned. ^This error 6108** code is not remembered and will not be recalled by [sqlite3_errcode()] 6109** or [sqlite3_errmsg()]. The underlying xFileControl method might 6110** also return SQLITE_ERROR. There is no way to distinguish between 6111** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6112** xFileControl method. 6113** 6114** See also: [SQLITE_FCNTL_LOCKSTATE] 6115*/ 6116int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6117 6118/* 6119** CAPI3REF: Testing Interface 6120** 6121** ^The sqlite3_test_control() interface is used to read out internal 6122** state of SQLite and to inject faults into SQLite for testing 6123** purposes. ^The first parameter is an operation code that determines 6124** the number, meaning, and operation of all subsequent parameters. 6125** 6126** This interface is not for use by applications. It exists solely 6127** for verifying the correct operation of the SQLite library. Depending 6128** on how the SQLite library is compiled, this interface might not exist. 6129** 6130** The details of the operation codes, their meanings, the parameters 6131** they take, and what they do are all subject to change without notice. 6132** Unlike most of the SQLite API, this function is not guaranteed to 6133** operate consistently from one release to the next. 6134*/ 6135int sqlite3_test_control(int op, ...); 6136 6137/* 6138** CAPI3REF: Testing Interface Operation Codes 6139** 6140** These constants are the valid operation code parameters used 6141** as the first argument to [sqlite3_test_control()]. 6142** 6143** These parameters and their meanings are subject to change 6144** without notice. These values are for testing purposes only. 6145** Applications should not use any of these parameters or the 6146** [sqlite3_test_control()] interface. 6147*/ 6148#define SQLITE_TESTCTRL_FIRST 5 6149#define SQLITE_TESTCTRL_PRNG_SAVE 5 6150#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6151#define SQLITE_TESTCTRL_PRNG_RESET 7 6152#define SQLITE_TESTCTRL_BITVEC_TEST 8 6153#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6154#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6155#define SQLITE_TESTCTRL_PENDING_BYTE 11 6156#define SQLITE_TESTCTRL_ASSERT 12 6157#define SQLITE_TESTCTRL_ALWAYS 13 6158#define SQLITE_TESTCTRL_RESERVE 14 6159#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6160#define SQLITE_TESTCTRL_ISKEYWORD 16 6161#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6162#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6163#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6164#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6165#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6166#define SQLITE_TESTCTRL_BYTEORDER 22 6167#define SQLITE_TESTCTRL_ISINIT 23 6168#define SQLITE_TESTCTRL_SORTER_MMAP 24 6169#define SQLITE_TESTCTRL_LAST 24 6170 6171/* 6172** CAPI3REF: SQLite Runtime Status 6173** 6174** ^This interface is used to retrieve runtime status information 6175** about the performance of SQLite, and optionally to reset various 6176** highwater marks. ^The first argument is an integer code for 6177** the specific parameter to measure. ^(Recognized integer codes 6178** are of the form [status parameters | SQLITE_STATUS_...].)^ 6179** ^The current value of the parameter is returned into *pCurrent. 6180** ^The highest recorded value is returned in *pHighwater. ^If the 6181** resetFlag is true, then the highest record value is reset after 6182** *pHighwater is written. ^(Some parameters do not record the highest 6183** value. For those parameters 6184** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6185** ^(Other parameters record only the highwater mark and not the current 6186** value. For these latter parameters nothing is written into *pCurrent.)^ 6187** 6188** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6189** non-zero [error code] on failure. 6190** 6191** This routine is threadsafe but is not atomic. This routine can be 6192** called while other threads are running the same or different SQLite 6193** interfaces. However the values returned in *pCurrent and 6194** *pHighwater reflect the status of SQLite at different points in time 6195** and it is possible that another thread might change the parameter 6196** in between the times when *pCurrent and *pHighwater are written. 6197** 6198** See also: [sqlite3_db_status()] 6199*/ 6200int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6201 6202 6203/* 6204** CAPI3REF: Status Parameters 6205** KEYWORDS: {status parameters} 6206** 6207** These integer constants designate various run-time status parameters 6208** that can be returned by [sqlite3_status()]. 6209** 6210** <dl> 6211** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6212** <dd>This parameter is the current amount of memory checked out 6213** using [sqlite3_malloc()], either directly or indirectly. The 6214** figure includes calls made to [sqlite3_malloc()] by the application 6215** and internal memory usage by the SQLite library. Scratch memory 6216** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6217** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6218** this parameter. The amount returned is the sum of the allocation 6219** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6220** 6221** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6222** <dd>This parameter records the largest memory allocation request 6223** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6224** internal equivalents). Only the value returned in the 6225** *pHighwater parameter to [sqlite3_status()] is of interest. 6226** The value written into the *pCurrent parameter is undefined.</dd>)^ 6227** 6228** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6229** <dd>This parameter records the number of separate memory allocations 6230** currently checked out.</dd>)^ 6231** 6232** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6233** <dd>This parameter returns the number of pages used out of the 6234** [pagecache memory allocator] that was configured using 6235** [SQLITE_CONFIG_PAGECACHE]. The 6236** value returned is in pages, not in bytes.</dd>)^ 6237** 6238** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6239** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6240** <dd>This parameter returns the number of bytes of page cache 6241** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6242** buffer and where forced to overflow to [sqlite3_malloc()]. The 6243** returned value includes allocations that overflowed because they 6244** where too large (they were larger than the "sz" parameter to 6245** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6246** no space was left in the page cache.</dd>)^ 6247** 6248** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6249** <dd>This parameter records the largest memory allocation request 6250** handed to [pagecache memory allocator]. Only the value returned in the 6251** *pHighwater parameter to [sqlite3_status()] is of interest. 6252** The value written into the *pCurrent parameter is undefined.</dd>)^ 6253** 6254** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6255** <dd>This parameter returns the number of allocations used out of the 6256** [scratch memory allocator] configured using 6257** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6258** in bytes. Since a single thread may only have one scratch allocation 6259** outstanding at time, this parameter also reports the number of threads 6260** using scratch memory at the same time.</dd>)^ 6261** 6262** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6263** <dd>This parameter returns the number of bytes of scratch memory 6264** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6265** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6266** returned include overflows because the requested allocation was too 6267** larger (that is, because the requested allocation was larger than the 6268** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6269** slots were available. 6270** </dd>)^ 6271** 6272** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6273** <dd>This parameter records the largest memory allocation request 6274** handed to [scratch memory allocator]. Only the value returned in the 6275** *pHighwater parameter to [sqlite3_status()] is of interest. 6276** The value written into the *pCurrent parameter is undefined.</dd>)^ 6277** 6278** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6279** <dd>This parameter records the deepest parser stack. It is only 6280** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6281** </dl> 6282** 6283** New status parameters may be added from time to time. 6284*/ 6285#define SQLITE_STATUS_MEMORY_USED 0 6286#define SQLITE_STATUS_PAGECACHE_USED 1 6287#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6288#define SQLITE_STATUS_SCRATCH_USED 3 6289#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6290#define SQLITE_STATUS_MALLOC_SIZE 5 6291#define SQLITE_STATUS_PARSER_STACK 6 6292#define SQLITE_STATUS_PAGECACHE_SIZE 7 6293#define SQLITE_STATUS_SCRATCH_SIZE 8 6294#define SQLITE_STATUS_MALLOC_COUNT 9 6295 6296/* 6297** CAPI3REF: Database Connection Status 6298** 6299** ^This interface is used to retrieve runtime status information 6300** about a single [database connection]. ^The first argument is the 6301** database connection object to be interrogated. ^The second argument 6302** is an integer constant, taken from the set of 6303** [SQLITE_DBSTATUS options], that 6304** determines the parameter to interrogate. The set of 6305** [SQLITE_DBSTATUS options] is likely 6306** to grow in future releases of SQLite. 6307** 6308** ^The current value of the requested parameter is written into *pCur 6309** and the highest instantaneous value is written into *pHiwtr. ^If 6310** the resetFlg is true, then the highest instantaneous value is 6311** reset back down to the current value. 6312** 6313** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6314** non-zero [error code] on failure. 6315** 6316** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6317*/ 6318int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6319 6320/* 6321** CAPI3REF: Status Parameters for database connections 6322** KEYWORDS: {SQLITE_DBSTATUS options} 6323** 6324** These constants are the available integer "verbs" that can be passed as 6325** the second argument to the [sqlite3_db_status()] interface. 6326** 6327** New verbs may be added in future releases of SQLite. Existing verbs 6328** might be discontinued. Applications should check the return code from 6329** [sqlite3_db_status()] to make sure that the call worked. 6330** The [sqlite3_db_status()] interface will return a non-zero error code 6331** if a discontinued or unsupported verb is invoked. 6332** 6333** <dl> 6334** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6335** <dd>This parameter returns the number of lookaside memory slots currently 6336** checked out.</dd>)^ 6337** 6338** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6339** <dd>This parameter returns the number malloc attempts that were 6340** satisfied using lookaside memory. Only the high-water value is meaningful; 6341** the current value is always zero.)^ 6342** 6343** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6344** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6345** <dd>This parameter returns the number malloc attempts that might have 6346** been satisfied using lookaside memory but failed due to the amount of 6347** memory requested being larger than the lookaside slot size. 6348** Only the high-water value is meaningful; 6349** the current value is always zero.)^ 6350** 6351** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6352** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6353** <dd>This parameter returns the number malloc attempts that might have 6354** been satisfied using lookaside memory but failed due to all lookaside 6355** memory already being in use. 6356** Only the high-water value is meaningful; 6357** the current value is always zero.)^ 6358** 6359** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6360** <dd>This parameter returns the approximate number of bytes of heap 6361** memory used by all pager caches associated with the database connection.)^ 6362** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6363** 6364** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6365** <dd>This parameter returns the approximate number of bytes of heap 6366** memory used to store the schema for all databases associated 6367** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6368** ^The full amount of memory used by the schemas is reported, even if the 6369** schema memory is shared with other database connections due to 6370** [shared cache mode] being enabled. 6371** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6372** 6373** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6374** <dd>This parameter returns the approximate number of bytes of heap 6375** and lookaside memory used by all prepared statements associated with 6376** the database connection.)^ 6377** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6378** </dd> 6379** 6380** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6381** <dd>This parameter returns the number of pager cache hits that have 6382** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6383** is always 0. 6384** </dd> 6385** 6386** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6387** <dd>This parameter returns the number of pager cache misses that have 6388** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6389** is always 0. 6390** </dd> 6391** 6392** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6393** <dd>This parameter returns the number of dirty cache entries that have 6394** been written to disk. Specifically, the number of pages written to the 6395** wal file in wal mode databases, or the number of pages written to the 6396** database file in rollback mode databases. Any pages written as part of 6397** transaction rollback or database recovery operations are not included. 6398** If an IO or other error occurs while writing a page to disk, the effect 6399** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6400** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6401** </dd> 6402** 6403** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6404** <dd>This parameter returns zero for the current value if and only if 6405** all foreign key constraints (deferred or immediate) have been 6406** resolved.)^ ^The highwater mark is always 0. 6407** </dd> 6408** </dl> 6409*/ 6410#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6411#define SQLITE_DBSTATUS_CACHE_USED 1 6412#define SQLITE_DBSTATUS_SCHEMA_USED 2 6413#define SQLITE_DBSTATUS_STMT_USED 3 6414#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6415#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6416#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6417#define SQLITE_DBSTATUS_CACHE_HIT 7 6418#define SQLITE_DBSTATUS_CACHE_MISS 8 6419#define SQLITE_DBSTATUS_CACHE_WRITE 9 6420#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6421#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6422 6423 6424/* 6425** CAPI3REF: Prepared Statement Status 6426** 6427** ^(Each prepared statement maintains various 6428** [SQLITE_STMTSTATUS counters] that measure the number 6429** of times it has performed specific operations.)^ These counters can 6430** be used to monitor the performance characteristics of the prepared 6431** statements. For example, if the number of table steps greatly exceeds 6432** the number of table searches or result rows, that would tend to indicate 6433** that the prepared statement is using a full table scan rather than 6434** an index. 6435** 6436** ^(This interface is used to retrieve and reset counter values from 6437** a [prepared statement]. The first argument is the prepared statement 6438** object to be interrogated. The second argument 6439** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6440** to be interrogated.)^ 6441** ^The current value of the requested counter is returned. 6442** ^If the resetFlg is true, then the counter is reset to zero after this 6443** interface call returns. 6444** 6445** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6446*/ 6447int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6448 6449/* 6450** CAPI3REF: Status Parameters for prepared statements 6451** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6452** 6453** These preprocessor macros define integer codes that name counter 6454** values associated with the [sqlite3_stmt_status()] interface. 6455** The meanings of the various counters are as follows: 6456** 6457** <dl> 6458** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6459** <dd>^This is the number of times that SQLite has stepped forward in 6460** a table as part of a full table scan. Large numbers for this counter 6461** may indicate opportunities for performance improvement through 6462** careful use of indices.</dd> 6463** 6464** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6465** <dd>^This is the number of sort operations that have occurred. 6466** A non-zero value in this counter may indicate an opportunity to 6467** improvement performance through careful use of indices.</dd> 6468** 6469** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6470** <dd>^This is the number of rows inserted into transient indices that 6471** were created automatically in order to help joins run faster. 6472** A non-zero value in this counter may indicate an opportunity to 6473** improvement performance by adding permanent indices that do not 6474** need to be reinitialized each time the statement is run.</dd> 6475** 6476** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6477** <dd>^This is the number of virtual machine operations executed 6478** by the prepared statement if that number is less than or equal 6479** to 2147483647. The number of virtual machine operations can be 6480** used as a proxy for the total work done by the prepared statement. 6481** If the number of virtual machine operations exceeds 2147483647 6482** then the value returned by this statement status code is undefined. 6483** </dd> 6484** </dl> 6485*/ 6486#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6487#define SQLITE_STMTSTATUS_SORT 2 6488#define SQLITE_STMTSTATUS_AUTOINDEX 3 6489#define SQLITE_STMTSTATUS_VM_STEP 4 6490 6491/* 6492** CAPI3REF: Custom Page Cache Object 6493** 6494** The sqlite3_pcache type is opaque. It is implemented by 6495** the pluggable module. The SQLite core has no knowledge of 6496** its size or internal structure and never deals with the 6497** sqlite3_pcache object except by holding and passing pointers 6498** to the object. 6499** 6500** See [sqlite3_pcache_methods2] for additional information. 6501*/ 6502typedef struct sqlite3_pcache sqlite3_pcache; 6503 6504/* 6505** CAPI3REF: Custom Page Cache Object 6506** 6507** The sqlite3_pcache_page object represents a single page in the 6508** page cache. The page cache will allocate instances of this 6509** object. Various methods of the page cache use pointers to instances 6510** of this object as parameters or as their return value. 6511** 6512** See [sqlite3_pcache_methods2] for additional information. 6513*/ 6514typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6515struct sqlite3_pcache_page { 6516 void *pBuf; /* The content of the page */ 6517 void *pExtra; /* Extra information associated with the page */ 6518}; 6519 6520/* 6521** CAPI3REF: Application Defined Page Cache. 6522** KEYWORDS: {page cache} 6523** 6524** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6525** register an alternative page cache implementation by passing in an 6526** instance of the sqlite3_pcache_methods2 structure.)^ 6527** In many applications, most of the heap memory allocated by 6528** SQLite is used for the page cache. 6529** By implementing a 6530** custom page cache using this API, an application can better control 6531** the amount of memory consumed by SQLite, the way in which 6532** that memory is allocated and released, and the policies used to 6533** determine exactly which parts of a database file are cached and for 6534** how long. 6535** 6536** The alternative page cache mechanism is an 6537** extreme measure that is only needed by the most demanding applications. 6538** The built-in page cache is recommended for most uses. 6539** 6540** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6541** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6542** the application may discard the parameter after the call to 6543** [sqlite3_config()] returns.)^ 6544** 6545** [[the xInit() page cache method]] 6546** ^(The xInit() method is called once for each effective 6547** call to [sqlite3_initialize()])^ 6548** (usually only once during the lifetime of the process). ^(The xInit() 6549** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6550** The intent of the xInit() method is to set up global data structures 6551** required by the custom page cache implementation. 6552** ^(If the xInit() method is NULL, then the 6553** built-in default page cache is used instead of the application defined 6554** page cache.)^ 6555** 6556** [[the xShutdown() page cache method]] 6557** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6558** It can be used to clean up 6559** any outstanding resources before process shutdown, if required. 6560** ^The xShutdown() method may be NULL. 6561** 6562** ^SQLite automatically serializes calls to the xInit method, 6563** so the xInit method need not be threadsafe. ^The 6564** xShutdown method is only called from [sqlite3_shutdown()] so it does 6565** not need to be threadsafe either. All other methods must be threadsafe 6566** in multithreaded applications. 6567** 6568** ^SQLite will never invoke xInit() more than once without an intervening 6569** call to xShutdown(). 6570** 6571** [[the xCreate() page cache methods]] 6572** ^SQLite invokes the xCreate() method to construct a new cache instance. 6573** SQLite will typically create one cache instance for each open database file, 6574** though this is not guaranteed. ^The 6575** first parameter, szPage, is the size in bytes of the pages that must 6576** be allocated by the cache. ^szPage will always a power of two. ^The 6577** second parameter szExtra is a number of bytes of extra storage 6578** associated with each page cache entry. ^The szExtra parameter will 6579** a number less than 250. SQLite will use the 6580** extra szExtra bytes on each page to store metadata about the underlying 6581** database page on disk. The value passed into szExtra depends 6582** on the SQLite version, the target platform, and how SQLite was compiled. 6583** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6584** created will be used to cache database pages of a file stored on disk, or 6585** false if it is used for an in-memory database. The cache implementation 6586** does not have to do anything special based with the value of bPurgeable; 6587** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6588** never invoke xUnpin() except to deliberately delete a page. 6589** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6590** false will always have the "discard" flag set to true. 6591** ^Hence, a cache created with bPurgeable false will 6592** never contain any unpinned pages. 6593** 6594** [[the xCachesize() page cache method]] 6595** ^(The xCachesize() method may be called at any time by SQLite to set the 6596** suggested maximum cache-size (number of pages stored by) the cache 6597** instance passed as the first argument. This is the value configured using 6598** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6599** parameter, the implementation is not required to do anything with this 6600** value; it is advisory only. 6601** 6602** [[the xPagecount() page cache methods]] 6603** The xPagecount() method must return the number of pages currently 6604** stored in the cache, both pinned and unpinned. 6605** 6606** [[the xFetch() page cache methods]] 6607** The xFetch() method locates a page in the cache and returns a pointer to 6608** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6609** The pBuf element of the returned sqlite3_pcache_page object will be a 6610** pointer to a buffer of szPage bytes used to store the content of a 6611** single database page. The pExtra element of sqlite3_pcache_page will be 6612** a pointer to the szExtra bytes of extra storage that SQLite has requested 6613** for each entry in the page cache. 6614** 6615** The page to be fetched is determined by the key. ^The minimum key value 6616** is 1. After it has been retrieved using xFetch, the page is considered 6617** to be "pinned". 6618** 6619** If the requested page is already in the page cache, then the page cache 6620** implementation must return a pointer to the page buffer with its content 6621** intact. If the requested page is not already in the cache, then the 6622** cache implementation should use the value of the createFlag 6623** parameter to help it determined what action to take: 6624** 6625** <table border=1 width=85% align=center> 6626** <tr><th> createFlag <th> Behavior when page is not already in cache 6627** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6628** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6629** Otherwise return NULL. 6630** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6631** NULL if allocating a new page is effectively impossible. 6632** </table> 6633** 6634** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6635** will only use a createFlag of 2 after a prior call with a createFlag of 1 6636** failed.)^ In between the to xFetch() calls, SQLite may 6637** attempt to unpin one or more cache pages by spilling the content of 6638** pinned pages to disk and synching the operating system disk cache. 6639** 6640** [[the xUnpin() page cache method]] 6641** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6642** as its second argument. If the third parameter, discard, is non-zero, 6643** then the page must be evicted from the cache. 6644** ^If the discard parameter is 6645** zero, then the page may be discarded or retained at the discretion of 6646** page cache implementation. ^The page cache implementation 6647** may choose to evict unpinned pages at any time. 6648** 6649** The cache must not perform any reference counting. A single 6650** call to xUnpin() unpins the page regardless of the number of prior calls 6651** to xFetch(). 6652** 6653** [[the xRekey() page cache methods]] 6654** The xRekey() method is used to change the key value associated with the 6655** page passed as the second argument. If the cache 6656** previously contains an entry associated with newKey, it must be 6657** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6658** to be pinned. 6659** 6660** When SQLite calls the xTruncate() method, the cache must discard all 6661** existing cache entries with page numbers (keys) greater than or equal 6662** to the value of the iLimit parameter passed to xTruncate(). If any 6663** of these pages are pinned, they are implicitly unpinned, meaning that 6664** they can be safely discarded. 6665** 6666** [[the xDestroy() page cache method]] 6667** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6668** All resources associated with the specified cache should be freed. ^After 6669** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6670** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6671** functions. 6672** 6673** [[the xShrink() page cache method]] 6674** ^SQLite invokes the xShrink() method when it wants the page cache to 6675** free up as much of heap memory as possible. The page cache implementation 6676** is not obligated to free any memory, but well-behaved implementations should 6677** do their best. 6678*/ 6679typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6680struct sqlite3_pcache_methods2 { 6681 int iVersion; 6682 void *pArg; 6683 int (*xInit)(void*); 6684 void (*xShutdown)(void*); 6685 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6686 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6687 int (*xPagecount)(sqlite3_pcache*); 6688 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6689 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6690 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6691 unsigned oldKey, unsigned newKey); 6692 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6693 void (*xDestroy)(sqlite3_pcache*); 6694 void (*xShrink)(sqlite3_pcache*); 6695}; 6696 6697/* 6698** This is the obsolete pcache_methods object that has now been replaced 6699** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6700** retained in the header file for backwards compatibility only. 6701*/ 6702typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6703struct sqlite3_pcache_methods { 6704 void *pArg; 6705 int (*xInit)(void*); 6706 void (*xShutdown)(void*); 6707 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6708 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6709 int (*xPagecount)(sqlite3_pcache*); 6710 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6711 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6712 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6713 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6714 void (*xDestroy)(sqlite3_pcache*); 6715}; 6716 6717 6718/* 6719** CAPI3REF: Online Backup Object 6720** 6721** The sqlite3_backup object records state information about an ongoing 6722** online backup operation. ^The sqlite3_backup object is created by 6723** a call to [sqlite3_backup_init()] and is destroyed by a call to 6724** [sqlite3_backup_finish()]. 6725** 6726** See Also: [Using the SQLite Online Backup API] 6727*/ 6728typedef struct sqlite3_backup sqlite3_backup; 6729 6730/* 6731** CAPI3REF: Online Backup API. 6732** 6733** The backup API copies the content of one database into another. 6734** It is useful either for creating backups of databases or 6735** for copying in-memory databases to or from persistent files. 6736** 6737** See Also: [Using the SQLite Online Backup API] 6738** 6739** ^SQLite holds a write transaction open on the destination database file 6740** for the duration of the backup operation. 6741** ^The source database is read-locked only while it is being read; 6742** it is not locked continuously for the entire backup operation. 6743** ^Thus, the backup may be performed on a live source database without 6744** preventing other database connections from 6745** reading or writing to the source database while the backup is underway. 6746** 6747** ^(To perform a backup operation: 6748** <ol> 6749** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6750** backup, 6751** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6752** the data between the two databases, and finally 6753** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6754** associated with the backup operation. 6755** </ol>)^ 6756** There should be exactly one call to sqlite3_backup_finish() for each 6757** successful call to sqlite3_backup_init(). 6758** 6759** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6760** 6761** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6762** [database connection] associated with the destination database 6763** and the database name, respectively. 6764** ^The database name is "main" for the main database, "temp" for the 6765** temporary database, or the name specified after the AS keyword in 6766** an [ATTACH] statement for an attached database. 6767** ^The S and M arguments passed to 6768** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6769** and database name of the source database, respectively. 6770** ^The source and destination [database connections] (parameters S and D) 6771** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6772** an error. 6773** 6774** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6775** returned and an error code and error message are stored in the 6776** destination [database connection] D. 6777** ^The error code and message for the failed call to sqlite3_backup_init() 6778** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6779** [sqlite3_errmsg16()] functions. 6780** ^A successful call to sqlite3_backup_init() returns a pointer to an 6781** [sqlite3_backup] object. 6782** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6783** sqlite3_backup_finish() functions to perform the specified backup 6784** operation. 6785** 6786** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6787** 6788** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6789** the source and destination databases specified by [sqlite3_backup] object B. 6790** ^If N is negative, all remaining source pages are copied. 6791** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6792** are still more pages to be copied, then the function returns [SQLITE_OK]. 6793** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6794** from source to destination, then it returns [SQLITE_DONE]. 6795** ^If an error occurs while running sqlite3_backup_step(B,N), 6796** then an [error code] is returned. ^As well as [SQLITE_OK] and 6797** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6798** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6799** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6800** 6801** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6802** <ol> 6803** <li> the destination database was opened read-only, or 6804** <li> the destination database is using write-ahead-log journaling 6805** and the destination and source page sizes differ, or 6806** <li> the destination database is an in-memory database and the 6807** destination and source page sizes differ. 6808** </ol>)^ 6809** 6810** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6811** the [sqlite3_busy_handler | busy-handler function] 6812** is invoked (if one is specified). ^If the 6813** busy-handler returns non-zero before the lock is available, then 6814** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6815** sqlite3_backup_step() can be retried later. ^If the source 6816** [database connection] 6817** is being used to write to the source database when sqlite3_backup_step() 6818** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6819** case the call to sqlite3_backup_step() can be retried later on. ^(If 6820** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6821** [SQLITE_READONLY] is returned, then 6822** there is no point in retrying the call to sqlite3_backup_step(). These 6823** errors are considered fatal.)^ The application must accept 6824** that the backup operation has failed and pass the backup operation handle 6825** to the sqlite3_backup_finish() to release associated resources. 6826** 6827** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6828** on the destination file. ^The exclusive lock is not released until either 6829** sqlite3_backup_finish() is called or the backup operation is complete 6830** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6831** sqlite3_backup_step() obtains a [shared lock] on the source database that 6832** lasts for the duration of the sqlite3_backup_step() call. 6833** ^Because the source database is not locked between calls to 6834** sqlite3_backup_step(), the source database may be modified mid-way 6835** through the backup process. ^If the source database is modified by an 6836** external process or via a database connection other than the one being 6837** used by the backup operation, then the backup will be automatically 6838** restarted by the next call to sqlite3_backup_step(). ^If the source 6839** database is modified by the using the same database connection as is used 6840** by the backup operation, then the backup database is automatically 6841** updated at the same time. 6842** 6843** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6844** 6845** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6846** application wishes to abandon the backup operation, the application 6847** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6848** ^The sqlite3_backup_finish() interfaces releases all 6849** resources associated with the [sqlite3_backup] object. 6850** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6851** active write-transaction on the destination database is rolled back. 6852** The [sqlite3_backup] object is invalid 6853** and may not be used following a call to sqlite3_backup_finish(). 6854** 6855** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6856** sqlite3_backup_step() errors occurred, regardless or whether or not 6857** sqlite3_backup_step() completed. 6858** ^If an out-of-memory condition or IO error occurred during any prior 6859** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6860** sqlite3_backup_finish() returns the corresponding [error code]. 6861** 6862** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6863** is not a permanent error and does not affect the return value of 6864** sqlite3_backup_finish(). 6865** 6866** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6867** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6868** 6869** ^Each call to sqlite3_backup_step() sets two values inside 6870** the [sqlite3_backup] object: the number of pages still to be backed 6871** up and the total number of pages in the source database file. 6872** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6873** retrieve these two values, respectively. 6874** 6875** ^The values returned by these functions are only updated by 6876** sqlite3_backup_step(). ^If the source database is modified during a backup 6877** operation, then the values are not updated to account for any extra 6878** pages that need to be updated or the size of the source database file 6879** changing. 6880** 6881** <b>Concurrent Usage of Database Handles</b> 6882** 6883** ^The source [database connection] may be used by the application for other 6884** purposes while a backup operation is underway or being initialized. 6885** ^If SQLite is compiled and configured to support threadsafe database 6886** connections, then the source database connection may be used concurrently 6887** from within other threads. 6888** 6889** However, the application must guarantee that the destination 6890** [database connection] is not passed to any other API (by any thread) after 6891** sqlite3_backup_init() is called and before the corresponding call to 6892** sqlite3_backup_finish(). SQLite does not currently check to see 6893** if the application incorrectly accesses the destination [database connection] 6894** and so no error code is reported, but the operations may malfunction 6895** nevertheless. Use of the destination database connection while a 6896** backup is in progress might also also cause a mutex deadlock. 6897** 6898** If running in [shared cache mode], the application must 6899** guarantee that the shared cache used by the destination database 6900** is not accessed while the backup is running. In practice this means 6901** that the application must guarantee that the disk file being 6902** backed up to is not accessed by any connection within the process, 6903** not just the specific connection that was passed to sqlite3_backup_init(). 6904** 6905** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6906** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6907** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6908** APIs are not strictly speaking threadsafe. If they are invoked at the 6909** same time as another thread is invoking sqlite3_backup_step() it is 6910** possible that they return invalid values. 6911*/ 6912sqlite3_backup *sqlite3_backup_init( 6913 sqlite3 *pDest, /* Destination database handle */ 6914 const char *zDestName, /* Destination database name */ 6915 sqlite3 *pSource, /* Source database handle */ 6916 const char *zSourceName /* Source database name */ 6917); 6918int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6919int sqlite3_backup_finish(sqlite3_backup *p); 6920int sqlite3_backup_remaining(sqlite3_backup *p); 6921int sqlite3_backup_pagecount(sqlite3_backup *p); 6922 6923/* 6924** CAPI3REF: Unlock Notification 6925** 6926** ^When running in shared-cache mode, a database operation may fail with 6927** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6928** individual tables within the shared-cache cannot be obtained. See 6929** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6930** ^This API may be used to register a callback that SQLite will invoke 6931** when the connection currently holding the required lock relinquishes it. 6932** ^This API is only available if the library was compiled with the 6933** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6934** 6935** See Also: [Using the SQLite Unlock Notification Feature]. 6936** 6937** ^Shared-cache locks are released when a database connection concludes 6938** its current transaction, either by committing it or rolling it back. 6939** 6940** ^When a connection (known as the blocked connection) fails to obtain a 6941** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6942** identity of the database connection (the blocking connection) that 6943** has locked the required resource is stored internally. ^After an 6944** application receives an SQLITE_LOCKED error, it may call the 6945** sqlite3_unlock_notify() method with the blocked connection handle as 6946** the first argument to register for a callback that will be invoked 6947** when the blocking connections current transaction is concluded. ^The 6948** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6949** call that concludes the blocking connections transaction. 6950** 6951** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6952** there is a chance that the blocking connection will have already 6953** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6954** If this happens, then the specified callback is invoked immediately, 6955** from within the call to sqlite3_unlock_notify().)^ 6956** 6957** ^If the blocked connection is attempting to obtain a write-lock on a 6958** shared-cache table, and more than one other connection currently holds 6959** a read-lock on the same table, then SQLite arbitrarily selects one of 6960** the other connections to use as the blocking connection. 6961** 6962** ^(There may be at most one unlock-notify callback registered by a 6963** blocked connection. If sqlite3_unlock_notify() is called when the 6964** blocked connection already has a registered unlock-notify callback, 6965** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6966** called with a NULL pointer as its second argument, then any existing 6967** unlock-notify callback is canceled. ^The blocked connections 6968** unlock-notify callback may also be canceled by closing the blocked 6969** connection using [sqlite3_close()]. 6970** 6971** The unlock-notify callback is not reentrant. If an application invokes 6972** any sqlite3_xxx API functions from within an unlock-notify callback, a 6973** crash or deadlock may be the result. 6974** 6975** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6976** returns SQLITE_OK. 6977** 6978** <b>Callback Invocation Details</b> 6979** 6980** When an unlock-notify callback is registered, the application provides a 6981** single void* pointer that is passed to the callback when it is invoked. 6982** However, the signature of the callback function allows SQLite to pass 6983** it an array of void* context pointers. The first argument passed to 6984** an unlock-notify callback is a pointer to an array of void* pointers, 6985** and the second is the number of entries in the array. 6986** 6987** When a blocking connections transaction is concluded, there may be 6988** more than one blocked connection that has registered for an unlock-notify 6989** callback. ^If two or more such blocked connections have specified the 6990** same callback function, then instead of invoking the callback function 6991** multiple times, it is invoked once with the set of void* context pointers 6992** specified by the blocked connections bundled together into an array. 6993** This gives the application an opportunity to prioritize any actions 6994** related to the set of unblocked database connections. 6995** 6996** <b>Deadlock Detection</b> 6997** 6998** Assuming that after registering for an unlock-notify callback a 6999** database waits for the callback to be issued before taking any further 7000** action (a reasonable assumption), then using this API may cause the 7001** application to deadlock. For example, if connection X is waiting for 7002** connection Y's transaction to be concluded, and similarly connection 7003** Y is waiting on connection X's transaction, then neither connection 7004** will proceed and the system may remain deadlocked indefinitely. 7005** 7006** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7007** detection. ^If a given call to sqlite3_unlock_notify() would put the 7008** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7009** unlock-notify callback is registered. The system is said to be in 7010** a deadlocked state if connection A has registered for an unlock-notify 7011** callback on the conclusion of connection B's transaction, and connection 7012** B has itself registered for an unlock-notify callback when connection 7013** A's transaction is concluded. ^Indirect deadlock is also detected, so 7014** the system is also considered to be deadlocked if connection B has 7015** registered for an unlock-notify callback on the conclusion of connection 7016** C's transaction, where connection C is waiting on connection A. ^Any 7017** number of levels of indirection are allowed. 7018** 7019** <b>The "DROP TABLE" Exception</b> 7020** 7021** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7022** always appropriate to call sqlite3_unlock_notify(). There is however, 7023** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7024** SQLite checks if there are any currently executing SELECT statements 7025** that belong to the same connection. If there are, SQLITE_LOCKED is 7026** returned. In this case there is no "blocking connection", so invoking 7027** sqlite3_unlock_notify() results in the unlock-notify callback being 7028** invoked immediately. If the application then re-attempts the "DROP TABLE" 7029** or "DROP INDEX" query, an infinite loop might be the result. 7030** 7031** One way around this problem is to check the extended error code returned 7032** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7033** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7034** the special "DROP TABLE/INDEX" case, the extended error code is just 7035** SQLITE_LOCKED.)^ 7036*/ 7037int sqlite3_unlock_notify( 7038 sqlite3 *pBlocked, /* Waiting connection */ 7039 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7040 void *pNotifyArg /* Argument to pass to xNotify */ 7041); 7042 7043 7044/* 7045** CAPI3REF: String Comparison 7046** 7047** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7048** and extensions to compare the contents of two buffers containing UTF-8 7049** strings in a case-independent fashion, using the same definition of "case 7050** independence" that SQLite uses internally when comparing identifiers. 7051*/ 7052int sqlite3_stricmp(const char *, const char *); 7053int sqlite3_strnicmp(const char *, const char *, int); 7054 7055/* 7056** CAPI3REF: String Globbing 7057* 7058** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7059** the glob pattern P, and it returns non-zero if string X does not match 7060** the glob pattern P. ^The definition of glob pattern matching used in 7061** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7062** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7063** sensitive. 7064** 7065** Note that this routine returns zero on a match and non-zero if the strings 7066** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7067*/ 7068int sqlite3_strglob(const char *zGlob, const char *zStr); 7069 7070/* 7071** CAPI3REF: Error Logging Interface 7072** 7073** ^The [sqlite3_log()] interface writes a message into the [error log] 7074** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7075** ^If logging is enabled, the zFormat string and subsequent arguments are 7076** used with [sqlite3_snprintf()] to generate the final output string. 7077** 7078** The sqlite3_log() interface is intended for use by extensions such as 7079** virtual tables, collating functions, and SQL functions. While there is 7080** nothing to prevent an application from calling sqlite3_log(), doing so 7081** is considered bad form. 7082** 7083** The zFormat string must not be NULL. 7084** 7085** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7086** will not use dynamically allocated memory. The log message is stored in 7087** a fixed-length buffer on the stack. If the log message is longer than 7088** a few hundred characters, it will be truncated to the length of the 7089** buffer. 7090*/ 7091void sqlite3_log(int iErrCode, const char *zFormat, ...); 7092 7093/* 7094** CAPI3REF: Write-Ahead Log Commit Hook 7095** 7096** ^The [sqlite3_wal_hook()] function is used to register a callback that 7097** will be invoked each time a database connection commits data to a 7098** [write-ahead log] (i.e. whenever a transaction is committed in 7099** [journal_mode | journal_mode=WAL mode]). 7100** 7101** ^The callback is invoked by SQLite after the commit has taken place and 7102** the associated write-lock on the database released, so the implementation 7103** may read, write or [checkpoint] the database as required. 7104** 7105** ^The first parameter passed to the callback function when it is invoked 7106** is a copy of the third parameter passed to sqlite3_wal_hook() when 7107** registering the callback. ^The second is a copy of the database handle. 7108** ^The third parameter is the name of the database that was written to - 7109** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7110** is the number of pages currently in the write-ahead log file, 7111** including those that were just committed. 7112** 7113** The callback function should normally return [SQLITE_OK]. ^If an error 7114** code is returned, that error will propagate back up through the 7115** SQLite code base to cause the statement that provoked the callback 7116** to report an error, though the commit will have still occurred. If the 7117** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7118** that does not correspond to any valid SQLite error code, the results 7119** are undefined. 7120** 7121** A single database handle may have at most a single write-ahead log callback 7122** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7123** previously registered write-ahead log callback. ^Note that the 7124** [sqlite3_wal_autocheckpoint()] interface and the 7125** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7126** those overwrite any prior [sqlite3_wal_hook()] settings. 7127*/ 7128void *sqlite3_wal_hook( 7129 sqlite3*, 7130 int(*)(void *,sqlite3*,const char*,int), 7131 void* 7132); 7133 7134/* 7135** CAPI3REF: Configure an auto-checkpoint 7136** 7137** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7138** [sqlite3_wal_hook()] that causes any database on [database connection] D 7139** to automatically [checkpoint] 7140** after committing a transaction if there are N or 7141** more frames in the [write-ahead log] file. ^Passing zero or 7142** a negative value as the nFrame parameter disables automatic 7143** checkpoints entirely. 7144** 7145** ^The callback registered by this function replaces any existing callback 7146** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7147** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7148** configured by this function. 7149** 7150** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7151** from SQL. 7152** 7153** ^Checkpoints initiated by this mechanism are 7154** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7155** 7156** ^Every new [database connection] defaults to having the auto-checkpoint 7157** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7158** pages. The use of this interface 7159** is only necessary if the default setting is found to be suboptimal 7160** for a particular application. 7161*/ 7162int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7163 7164/* 7165** CAPI3REF: Checkpoint a database 7166** 7167** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 7168** on [database connection] D to be [checkpointed]. ^If X is NULL or an 7169** empty string, then a checkpoint is run on all databases of 7170** connection D. ^If the database connection D is not in 7171** [WAL | write-ahead log mode] then this interface is a harmless no-op. 7172** ^The [sqlite3_wal_checkpoint(D,X)] interface initiates a 7173** [sqlite3_wal_checkpoint_v2|PASSIVE] checkpoint. 7174** Use the [sqlite3_wal_checkpoint_v2()] interface to get a FULL 7175** or RESET checkpoint. 7176** 7177** ^The [wal_checkpoint pragma] can be used to invoke this interface 7178** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 7179** [wal_autocheckpoint pragma] can be used to cause this interface to be 7180** run whenever the WAL reaches a certain size threshold. 7181** 7182** See also: [sqlite3_wal_checkpoint_v2()] 7183*/ 7184int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7185 7186/* 7187** CAPI3REF: Checkpoint a database 7188** 7189** Run a checkpoint operation on WAL database zDb attached to database 7190** handle db. The specific operation is determined by the value of the 7191** eMode parameter: 7192** 7193** <dl> 7194** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7195** Checkpoint as many frames as possible without waiting for any database 7196** readers or writers to finish. Sync the db file if all frames in the log 7197** are checkpointed. This mode is the same as calling 7198** sqlite3_wal_checkpoint(). The [sqlite3_busy_handler|busy-handler callback] 7199** is never invoked. 7200** 7201** <dt>SQLITE_CHECKPOINT_FULL<dd> 7202** This mode blocks (it invokes the 7203** [sqlite3_busy_handler|busy-handler callback]) until there is no 7204** database writer and all readers are reading from the most recent database 7205** snapshot. It then checkpoints all frames in the log file and syncs the 7206** database file. This call blocks database writers while it is running, 7207** but not database readers. 7208** 7209** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7210** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7211** checkpointing the log file it blocks (calls the 7212** [sqlite3_busy_handler|busy-handler callback]) 7213** until all readers are reading from the database file only. This ensures 7214** that the next client to write to the database file restarts the log file 7215** from the beginning. This call blocks database writers while it is running, 7216** but not database readers. 7217** </dl> 7218** 7219** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7220** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7221** the total number of checkpointed frames (including any that were already 7222** checkpointed when this function is called). *pnLog and *pnCkpt may be 7223** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7224** If no values are available because of an error, they are both set to -1 7225** before returning to communicate this to the caller. 7226** 7227** All calls obtain an exclusive "checkpoint" lock on the database file. If 7228** any other process is running a checkpoint operation at the same time, the 7229** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7230** busy-handler configured, it will not be invoked in this case. 7231** 7232** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7233** "writer" lock on the database file. If the writer lock cannot be obtained 7234** immediately, and a busy-handler is configured, it is invoked and the writer 7235** lock retried until either the busy-handler returns 0 or the lock is 7236** successfully obtained. The busy-handler is also invoked while waiting for 7237** database readers as described above. If the busy-handler returns 0 before 7238** the writer lock is obtained or while waiting for database readers, the 7239** checkpoint operation proceeds from that point in the same way as 7240** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7241** without blocking any further. SQLITE_BUSY is returned in this case. 7242** 7243** If parameter zDb is NULL or points to a zero length string, then the 7244** specified operation is attempted on all WAL databases. In this case the 7245** values written to output parameters *pnLog and *pnCkpt are undefined. If 7246** an SQLITE_BUSY error is encountered when processing one or more of the 7247** attached WAL databases, the operation is still attempted on any remaining 7248** attached databases and SQLITE_BUSY is returned to the caller. If any other 7249** error occurs while processing an attached database, processing is abandoned 7250** and the error code returned to the caller immediately. If no error 7251** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7252** databases, SQLITE_OK is returned. 7253** 7254** If database zDb is the name of an attached database that is not in WAL 7255** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7256** zDb is not NULL (or a zero length string) and is not the name of any 7257** attached database, SQLITE_ERROR is returned to the caller. 7258*/ 7259int sqlite3_wal_checkpoint_v2( 7260 sqlite3 *db, /* Database handle */ 7261 const char *zDb, /* Name of attached database (or NULL) */ 7262 int eMode, /* SQLITE_CHECKPOINT_* value */ 7263 int *pnLog, /* OUT: Size of WAL log in frames */ 7264 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7265); 7266 7267/* 7268** CAPI3REF: Checkpoint operation parameters 7269** 7270** These constants can be used as the 3rd parameter to 7271** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7272** documentation for additional information about the meaning and use of 7273** each of these values. 7274*/ 7275#define SQLITE_CHECKPOINT_PASSIVE 0 7276#define SQLITE_CHECKPOINT_FULL 1 7277#define SQLITE_CHECKPOINT_RESTART 2 7278 7279/* 7280** CAPI3REF: Virtual Table Interface Configuration 7281** 7282** This function may be called by either the [xConnect] or [xCreate] method 7283** of a [virtual table] implementation to configure 7284** various facets of the virtual table interface. 7285** 7286** If this interface is invoked outside the context of an xConnect or 7287** xCreate virtual table method then the behavior is undefined. 7288** 7289** At present, there is only one option that may be configured using 7290** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7291** may be added in the future. 7292*/ 7293int sqlite3_vtab_config(sqlite3*, int op, ...); 7294 7295/* 7296** CAPI3REF: Virtual Table Configuration Options 7297** 7298** These macros define the various options to the 7299** [sqlite3_vtab_config()] interface that [virtual table] implementations 7300** can use to customize and optimize their behavior. 7301** 7302** <dl> 7303** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7304** <dd>Calls of the form 7305** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7306** where X is an integer. If X is zero, then the [virtual table] whose 7307** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7308** support constraints. In this configuration (which is the default) if 7309** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7310** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7311** specified as part of the users SQL statement, regardless of the actual 7312** ON CONFLICT mode specified. 7313** 7314** If X is non-zero, then the virtual table implementation guarantees 7315** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7316** any modifications to internal or persistent data structures have been made. 7317** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7318** is able to roll back a statement or database transaction, and abandon 7319** or continue processing the current SQL statement as appropriate. 7320** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7321** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7322** had been ABORT. 7323** 7324** Virtual table implementations that are required to handle OR REPLACE 7325** must do so within the [xUpdate] method. If a call to the 7326** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7327** CONFLICT policy is REPLACE, the virtual table implementation should 7328** silently replace the appropriate rows within the xUpdate callback and 7329** return SQLITE_OK. Or, if this is not possible, it may return 7330** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7331** constraint handling. 7332** </dl> 7333*/ 7334#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7335 7336/* 7337** CAPI3REF: Determine The Virtual Table Conflict Policy 7338** 7339** This function may only be called from within a call to the [xUpdate] method 7340** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7341** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7342** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7343** of the SQL statement that triggered the call to the [xUpdate] method of the 7344** [virtual table]. 7345*/ 7346int sqlite3_vtab_on_conflict(sqlite3 *); 7347 7348/* 7349** CAPI3REF: Conflict resolution modes 7350** KEYWORDS: {conflict resolution mode} 7351** 7352** These constants are returned by [sqlite3_vtab_on_conflict()] to 7353** inform a [virtual table] implementation what the [ON CONFLICT] mode 7354** is for the SQL statement being evaluated. 7355** 7356** Note that the [SQLITE_IGNORE] constant is also used as a potential 7357** return value from the [sqlite3_set_authorizer()] callback and that 7358** [SQLITE_ABORT] is also a [result code]. 7359*/ 7360#define SQLITE_ROLLBACK 1 7361/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7362#define SQLITE_FAIL 3 7363/* #define SQLITE_ABORT 4 // Also an error code */ 7364#define SQLITE_REPLACE 5 7365 7366 7367 7368/* 7369** Undo the hack that converts floating point types to integer for 7370** builds on processors without floating point support. 7371*/ 7372#ifdef SQLITE_OMIT_FLOATING_POINT 7373# undef double 7374#endif 7375 7376#ifdef __cplusplus 7377} /* End of the 'extern "C"' block */ 7378#endif 7379#endif /* _SQLITE3_H_ */ 7380