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#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 496 497/* 498** CAPI3REF: Flags For File Open Operations 499** 500** These bit values are intended for use in the 501** 3rd parameter to the [sqlite3_open_v2()] interface and 502** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 503*/ 504#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 505#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 506#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 507#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 508#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 509#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 510#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 511#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 512#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 513#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 514#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 515#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 516#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 517#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 518#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 519#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 520#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 521#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 522#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 523#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 524 525/* Reserved: 0x00F00000 */ 526 527/* 528** CAPI3REF: Device Characteristics 529** 530** The xDeviceCharacteristics method of the [sqlite3_io_methods] 531** object returns an integer which is a vector of these 532** bit values expressing I/O characteristics of the mass storage 533** device that holds the file that the [sqlite3_io_methods] 534** refers to. 535** 536** The SQLITE_IOCAP_ATOMIC property means that all writes of 537** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 538** mean that writes of blocks that are nnn bytes in size and 539** are aligned to an address which is an integer multiple of 540** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 541** that when data is appended to a file, the data is appended 542** first then the size of the file is extended, never the other 543** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 544** information is written to disk in the same order as calls 545** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 546** after reboot following a crash or power loss, the only bytes in a 547** file that were written at the application level might have changed 548** and that adjacent bytes, even bytes within the same sector are 549** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 550** flag indicate that a file cannot be deleted when open. The 551** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 552** read-only media and cannot be changed even by processes with 553** elevated privileges. 554*/ 555#define SQLITE_IOCAP_ATOMIC 0x00000001 556#define SQLITE_IOCAP_ATOMIC512 0x00000002 557#define SQLITE_IOCAP_ATOMIC1K 0x00000004 558#define SQLITE_IOCAP_ATOMIC2K 0x00000008 559#define SQLITE_IOCAP_ATOMIC4K 0x00000010 560#define SQLITE_IOCAP_ATOMIC8K 0x00000020 561#define SQLITE_IOCAP_ATOMIC16K 0x00000040 562#define SQLITE_IOCAP_ATOMIC32K 0x00000080 563#define SQLITE_IOCAP_ATOMIC64K 0x00000100 564#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 565#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 566#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 567#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 568#define SQLITE_IOCAP_IMMUTABLE 0x00002000 569 570/* 571** CAPI3REF: File Locking Levels 572** 573** SQLite uses one of these integer values as the second 574** argument to calls it makes to the xLock() and xUnlock() methods 575** of an [sqlite3_io_methods] object. 576*/ 577#define SQLITE_LOCK_NONE 0 578#define SQLITE_LOCK_SHARED 1 579#define SQLITE_LOCK_RESERVED 2 580#define SQLITE_LOCK_PENDING 3 581#define SQLITE_LOCK_EXCLUSIVE 4 582 583/* 584** CAPI3REF: Synchronization Type Flags 585** 586** When SQLite invokes the xSync() method of an 587** [sqlite3_io_methods] object it uses a combination of 588** these integer values as the second argument. 589** 590** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 591** sync operation only needs to flush data to mass storage. Inode 592** information need not be flushed. If the lower four bits of the flag 593** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 594** If the lower four bits equal SQLITE_SYNC_FULL, that means 595** to use Mac OS X style fullsync instead of fsync(). 596** 597** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 598** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 599** settings. The [synchronous pragma] determines when calls to the 600** xSync VFS method occur and applies uniformly across all platforms. 601** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 602** energetic or rigorous or forceful the sync operations are and 603** only make a difference on Mac OSX for the default SQLite code. 604** (Third-party VFS implementations might also make the distinction 605** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 606** operating systems natively supported by SQLite, only Mac OSX 607** cares about the difference.) 608*/ 609#define SQLITE_SYNC_NORMAL 0x00002 610#define SQLITE_SYNC_FULL 0x00003 611#define SQLITE_SYNC_DATAONLY 0x00010 612 613/* 614** CAPI3REF: OS Interface Open File Handle 615** 616** An [sqlite3_file] object represents an open file in the 617** [sqlite3_vfs | OS interface layer]. Individual OS interface 618** implementations will 619** want to subclass this object by appending additional fields 620** for their own use. The pMethods entry is a pointer to an 621** [sqlite3_io_methods] object that defines methods for performing 622** I/O operations on the open file. 623*/ 624typedef struct sqlite3_file sqlite3_file; 625struct sqlite3_file { 626 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 627}; 628 629/* 630** CAPI3REF: OS Interface File Virtual Methods Object 631** 632** Every file opened by the [sqlite3_vfs.xOpen] method populates an 633** [sqlite3_file] object (or, more commonly, a subclass of the 634** [sqlite3_file] object) with a pointer to an instance of this object. 635** This object defines the methods used to perform various operations 636** against the open file represented by the [sqlite3_file] object. 637** 638** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 639** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 640** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 641** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 642** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 643** to NULL. 644** 645** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 646** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 647** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 648** flag may be ORed in to indicate that only the data of the file 649** and not its inode needs to be synced. 650** 651** The integer values to xLock() and xUnlock() are one of 652** <ul> 653** <li> [SQLITE_LOCK_NONE], 654** <li> [SQLITE_LOCK_SHARED], 655** <li> [SQLITE_LOCK_RESERVED], 656** <li> [SQLITE_LOCK_PENDING], or 657** <li> [SQLITE_LOCK_EXCLUSIVE]. 658** </ul> 659** xLock() increases the lock. xUnlock() decreases the lock. 660** The xCheckReservedLock() method checks whether any database connection, 661** either in this process or in some other process, is holding a RESERVED, 662** PENDING, or EXCLUSIVE lock on the file. It returns true 663** if such a lock exists and false otherwise. 664** 665** The xFileControl() method is a generic interface that allows custom 666** VFS implementations to directly control an open file using the 667** [sqlite3_file_control()] interface. The second "op" argument is an 668** integer opcode. The third argument is a generic pointer intended to 669** point to a structure that may contain arguments or space in which to 670** write return values. Potential uses for xFileControl() might be 671** functions to enable blocking locks with timeouts, to change the 672** locking strategy (for example to use dot-file locks), to inquire 673** about the status of a lock, or to break stale locks. The SQLite 674** core reserves all opcodes less than 100 for its own use. 675** A [file control opcodes | list of opcodes] less than 100 is available. 676** Applications that define a custom xFileControl method should use opcodes 677** greater than 100 to avoid conflicts. VFS implementations should 678** return [SQLITE_NOTFOUND] for file control opcodes that they do not 679** recognize. 680** 681** The xSectorSize() method returns the sector size of the 682** device that underlies the file. The sector size is the 683** minimum write that can be performed without disturbing 684** other bytes in the file. The xDeviceCharacteristics() 685** method returns a bit vector describing behaviors of the 686** underlying device: 687** 688** <ul> 689** <li> [SQLITE_IOCAP_ATOMIC] 690** <li> [SQLITE_IOCAP_ATOMIC512] 691** <li> [SQLITE_IOCAP_ATOMIC1K] 692** <li> [SQLITE_IOCAP_ATOMIC2K] 693** <li> [SQLITE_IOCAP_ATOMIC4K] 694** <li> [SQLITE_IOCAP_ATOMIC8K] 695** <li> [SQLITE_IOCAP_ATOMIC16K] 696** <li> [SQLITE_IOCAP_ATOMIC32K] 697** <li> [SQLITE_IOCAP_ATOMIC64K] 698** <li> [SQLITE_IOCAP_SAFE_APPEND] 699** <li> [SQLITE_IOCAP_SEQUENTIAL] 700** </ul> 701** 702** The SQLITE_IOCAP_ATOMIC property means that all writes of 703** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 704** mean that writes of blocks that are nnn bytes in size and 705** are aligned to an address which is an integer multiple of 706** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 707** that when data is appended to a file, the data is appended 708** first then the size of the file is extended, never the other 709** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 710** information is written to disk in the same order as calls 711** to xWrite(). 712** 713** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 714** in the unread portions of the buffer with zeros. A VFS that 715** fails to zero-fill short reads might seem to work. However, 716** failure to zero-fill short reads will eventually lead to 717** database corruption. 718*/ 719typedef struct sqlite3_io_methods sqlite3_io_methods; 720struct sqlite3_io_methods { 721 int iVersion; 722 int (*xClose)(sqlite3_file*); 723 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 724 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 725 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 726 int (*xSync)(sqlite3_file*, int flags); 727 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 728 int (*xLock)(sqlite3_file*, int); 729 int (*xUnlock)(sqlite3_file*, int); 730 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 731 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 732 int (*xSectorSize)(sqlite3_file*); 733 int (*xDeviceCharacteristics)(sqlite3_file*); 734 /* Methods above are valid for version 1 */ 735 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 736 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 737 void (*xShmBarrier)(sqlite3_file*); 738 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 739 /* Methods above are valid for version 2 */ 740 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 741 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 742 /* Methods above are valid for version 3 */ 743 /* Additional methods may be added in future releases */ 744}; 745 746/* 747** CAPI3REF: Standard File Control Opcodes 748** KEYWORDS: {file control opcodes} {file control opcode} 749** 750** These integer constants are opcodes for the xFileControl method 751** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 752** interface. 753** 754** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 755** opcode causes the xFileControl method to write the current state of 756** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 757** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 758** into an integer that the pArg argument points to. This capability 759** is used during testing and only needs to be supported when SQLITE_TEST 760** is defined. 761** <ul> 762** <li>[[SQLITE_FCNTL_SIZE_HINT]] 763** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 764** layer a hint of how large the database file will grow to be during the 765** current transaction. This hint is not guaranteed to be accurate but it 766** is often close. The underlying VFS might choose to preallocate database 767** file space based on this hint in order to help writes to the database 768** file run faster. 769** 770** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 771** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 772** extends and truncates the database file in chunks of a size specified 773** by the user. The fourth argument to [sqlite3_file_control()] should 774** point to an integer (type int) containing the new chunk-size to use 775** for the nominated database. Allocating database file space in large 776** chunks (say 1MB at a time), may reduce file-system fragmentation and 777** improve performance on some systems. 778** 779** <li>[[SQLITE_FCNTL_FILE_POINTER]] 780** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 781** to the [sqlite3_file] object associated with a particular database 782** connection. See the [sqlite3_file_control()] documentation for 783** additional information. 784** 785** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 786** No longer in use. 787** 788** <li>[[SQLITE_FCNTL_SYNC]] 789** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 790** sent to the VFS immediately before the xSync method is invoked on a 791** database file descriptor. Or, if the xSync method is not invoked 792** because the user has configured SQLite with 793** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 794** of the xSync method. In most cases, the pointer argument passed with 795** this file-control is NULL. However, if the database file is being synced 796** as part of a multi-database commit, the argument points to a nul-terminated 797** string containing the transactions master-journal file name. VFSes that 798** do not need this signal should silently ignore this opcode. Applications 799** should not call [sqlite3_file_control()] with this opcode as doing so may 800** disrupt the operation of the specialized VFSes that do require it. 801** 802** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 803** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 804** and sent to the VFS after a transaction has been committed immediately 805** but before the database is unlocked. VFSes that do not need this signal 806** should silently ignore this opcode. Applications should not call 807** [sqlite3_file_control()] with this opcode as doing so may disrupt the 808** operation of the specialized VFSes that do require it. 809** 810** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 811** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 812** retry counts and intervals for certain disk I/O operations for the 813** windows [VFS] in order to provide robustness in the presence of 814** anti-virus programs. By default, the windows VFS will retry file read, 815** file write, and file delete operations up to 10 times, with a delay 816** of 25 milliseconds before the first retry and with the delay increasing 817** by an additional 25 milliseconds with each subsequent retry. This 818** opcode allows these two values (10 retries and 25 milliseconds of delay) 819** to be adjusted. The values are changed for all database connections 820** within the same process. The argument is a pointer to an array of two 821** integers where the first integer i the new retry count and the second 822** integer is the delay. If either integer is negative, then the setting 823** is not changed but instead the prior value of that setting is written 824** into the array entry, allowing the current retry settings to be 825** interrogated. The zDbName parameter is ignored. 826** 827** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 828** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 829** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 830** write ahead log and shared memory files used for transaction control 831** are automatically deleted when the latest connection to the database 832** closes. Setting persistent WAL mode causes those files to persist after 833** close. Persisting the files is useful when other processes that do not 834** have write permission on the directory containing the database file want 835** to read the database file, as the WAL and shared memory files must exist 836** in order for the database to be readable. The fourth parameter to 837** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 838** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 839** WAL mode. If the integer is -1, then it is overwritten with the current 840** WAL persistence setting. 841** 842** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 843** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 844** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 845** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 846** xDeviceCharacteristics methods. The fourth parameter to 847** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 848** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 849** mode. If the integer is -1, then it is overwritten with the current 850** zero-damage mode setting. 851** 852** <li>[[SQLITE_FCNTL_OVERWRITE]] 853** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 854** a write transaction to indicate that, unless it is rolled back for some 855** reason, the entire database file will be overwritten by the current 856** transaction. This is used by VACUUM operations. 857** 858** <li>[[SQLITE_FCNTL_VFSNAME]] 859** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 860** all [VFSes] in the VFS stack. The names are of all VFS shims and the 861** final bottom-level VFS are written into memory obtained from 862** [sqlite3_malloc()] and the result is stored in the char* variable 863** that the fourth parameter of [sqlite3_file_control()] points to. 864** The caller is responsible for freeing the memory when done. As with 865** all file-control actions, there is no guarantee that this will actually 866** do anything. Callers should initialize the char* variable to a NULL 867** pointer in case this file-control is not implemented. This file-control 868** is intended for diagnostic use only. 869** 870** <li>[[SQLITE_FCNTL_PRAGMA]] 871** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 872** file control is sent to the open [sqlite3_file] object corresponding 873** to the database file to which the pragma statement refers. ^The argument 874** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 875** pointers to strings (char**) in which the second element of the array 876** is the name of the pragma and the third element is the argument to the 877** pragma or NULL if the pragma has no argument. ^The handler for an 878** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 879** of the char** argument point to a string obtained from [sqlite3_mprintf()] 880** or the equivalent and that string will become the result of the pragma or 881** the error message if the pragma fails. ^If the 882** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 883** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 884** file control returns [SQLITE_OK], then the parser assumes that the 885** VFS has handled the PRAGMA itself and the parser generates a no-op 886** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 887** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 888** that the VFS encountered an error while handling the [PRAGMA] and the 889** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 890** file control occurs at the beginning of pragma statement analysis and so 891** it is able to override built-in [PRAGMA] statements. 892** 893** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 894** ^The [SQLITE_FCNTL_BUSYHANDLER] 895** file-control may be invoked by SQLite on the database file handle 896** shortly after it is opened in order to provide a custom VFS with access 897** to the connections busy-handler callback. The argument is of type (void **) 898** - an array of two (void *) values. The first (void *) actually points 899** to a function of type (int (*)(void *)). In order to invoke the connections 900** busy-handler, this function should be invoked with the second (void *) in 901** the array as the only argument. If it returns non-zero, then the operation 902** should be retried. If it returns zero, the custom VFS should abandon the 903** current operation. 904** 905** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 906** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 907** to have SQLite generate a 908** temporary filename using the same algorithm that is followed to generate 909** temporary filenames for TEMP tables and other internal uses. The 910** argument should be a char** which will be filled with the filename 911** written into memory obtained from [sqlite3_malloc()]. The caller should 912** invoke [sqlite3_free()] on the result to avoid a memory leak. 913** 914** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 915** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 916** maximum number of bytes that will be used for memory-mapped I/O. 917** The argument is a pointer to a value of type sqlite3_int64 that 918** is an advisory maximum number of bytes in the file to memory map. The 919** pointer is overwritten with the old value. The limit is not changed if 920** the value originally pointed to is negative, and so the current limit 921** can be queried by passing in a pointer to a negative number. This 922** file-control is used internally to implement [PRAGMA mmap_size]. 923** 924** <li>[[SQLITE_FCNTL_TRACE]] 925** The [SQLITE_FCNTL_TRACE] file control provides advisory information 926** to the VFS about what the higher layers of the SQLite stack are doing. 927** This file control is used by some VFS activity tracing [shims]. 928** The argument is a zero-terminated string. Higher layers in the 929** SQLite stack may generate instances of this file control if 930** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 931** 932** <li>[[SQLITE_FCNTL_HAS_MOVED]] 933** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 934** pointer to an integer and it writes a boolean into that integer depending 935** on whether or not the file has been renamed, moved, or deleted since it 936** was first opened. 937** 938** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 939** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 940** opcode causes the xFileControl method to swap the file handle with the one 941** pointed to by the pArg argument. This capability is used during testing 942** and only needs to be supported when SQLITE_TEST is defined. 943** 944** </ul> 945*/ 946#define SQLITE_FCNTL_LOCKSTATE 1 947#define SQLITE_GET_LOCKPROXYFILE 2 948#define SQLITE_SET_LOCKPROXYFILE 3 949#define SQLITE_LAST_ERRNO 4 950#define SQLITE_FCNTL_SIZE_HINT 5 951#define SQLITE_FCNTL_CHUNK_SIZE 6 952#define SQLITE_FCNTL_FILE_POINTER 7 953#define SQLITE_FCNTL_SYNC_OMITTED 8 954#define SQLITE_FCNTL_WIN32_AV_RETRY 9 955#define SQLITE_FCNTL_PERSIST_WAL 10 956#define SQLITE_FCNTL_OVERWRITE 11 957#define SQLITE_FCNTL_VFSNAME 12 958#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 959#define SQLITE_FCNTL_PRAGMA 14 960#define SQLITE_FCNTL_BUSYHANDLER 15 961#define SQLITE_FCNTL_TEMPFILENAME 16 962#define SQLITE_FCNTL_MMAP_SIZE 18 963#define SQLITE_FCNTL_TRACE 19 964#define SQLITE_FCNTL_HAS_MOVED 20 965#define SQLITE_FCNTL_SYNC 21 966#define SQLITE_FCNTL_COMMIT_PHASETWO 22 967#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 968 969/* 970** CAPI3REF: Mutex Handle 971** 972** The mutex module within SQLite defines [sqlite3_mutex] to be an 973** abstract type for a mutex object. The SQLite core never looks 974** at the internal representation of an [sqlite3_mutex]. It only 975** deals with pointers to the [sqlite3_mutex] object. 976** 977** Mutexes are created using [sqlite3_mutex_alloc()]. 978*/ 979typedef struct sqlite3_mutex sqlite3_mutex; 980 981/* 982** CAPI3REF: OS Interface Object 983** 984** An instance of the sqlite3_vfs object defines the interface between 985** the SQLite core and the underlying operating system. The "vfs" 986** in the name of the object stands for "virtual file system". See 987** the [VFS | VFS documentation] for further information. 988** 989** The value of the iVersion field is initially 1 but may be larger in 990** future versions of SQLite. Additional fields may be appended to this 991** object when the iVersion value is increased. Note that the structure 992** of the sqlite3_vfs object changes in the transaction between 993** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 994** modified. 995** 996** The szOsFile field is the size of the subclassed [sqlite3_file] 997** structure used by this VFS. mxPathname is the maximum length of 998** a pathname in this VFS. 999** 1000** Registered sqlite3_vfs objects are kept on a linked list formed by 1001** the pNext pointer. The [sqlite3_vfs_register()] 1002** and [sqlite3_vfs_unregister()] interfaces manage this list 1003** in a thread-safe way. The [sqlite3_vfs_find()] interface 1004** searches the list. Neither the application code nor the VFS 1005** implementation should use the pNext pointer. 1006** 1007** The pNext field is the only field in the sqlite3_vfs 1008** structure that SQLite will ever modify. SQLite will only access 1009** or modify this field while holding a particular static mutex. 1010** The application should never modify anything within the sqlite3_vfs 1011** object once the object has been registered. 1012** 1013** The zName field holds the name of the VFS module. The name must 1014** be unique across all VFS modules. 1015** 1016** [[sqlite3_vfs.xOpen]] 1017** ^SQLite guarantees that the zFilename parameter to xOpen 1018** is either a NULL pointer or string obtained 1019** from xFullPathname() with an optional suffix added. 1020** ^If a suffix is added to the zFilename parameter, it will 1021** consist of a single "-" character followed by no more than 1022** 11 alphanumeric and/or "-" characters. 1023** ^SQLite further guarantees that 1024** the string will be valid and unchanged until xClose() is 1025** called. Because of the previous sentence, 1026** the [sqlite3_file] can safely store a pointer to the 1027** filename if it needs to remember the filename for some reason. 1028** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1029** must invent its own temporary name for the file. ^Whenever the 1030** xFilename parameter is NULL it will also be the case that the 1031** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1032** 1033** The flags argument to xOpen() includes all bits set in 1034** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1035** or [sqlite3_open16()] is used, then flags includes at least 1036** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1037** If xOpen() opens a file read-only then it sets *pOutFlags to 1038** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1039** 1040** ^(SQLite will also add one of the following flags to the xOpen() 1041** call, depending on the object being opened: 1042** 1043** <ul> 1044** <li> [SQLITE_OPEN_MAIN_DB] 1045** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1046** <li> [SQLITE_OPEN_TEMP_DB] 1047** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1048** <li> [SQLITE_OPEN_TRANSIENT_DB] 1049** <li> [SQLITE_OPEN_SUBJOURNAL] 1050** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1051** <li> [SQLITE_OPEN_WAL] 1052** </ul>)^ 1053** 1054** The file I/O implementation can use the object type flags to 1055** change the way it deals with files. For example, an application 1056** that does not care about crash recovery or rollback might make 1057** the open of a journal file a no-op. Writes to this journal would 1058** also be no-ops, and any attempt to read the journal would return 1059** SQLITE_IOERR. Or the implementation might recognize that a database 1060** file will be doing page-aligned sector reads and writes in a random 1061** order and set up its I/O subsystem accordingly. 1062** 1063** SQLite might also add one of the following flags to the xOpen method: 1064** 1065** <ul> 1066** <li> [SQLITE_OPEN_DELETEONCLOSE] 1067** <li> [SQLITE_OPEN_EXCLUSIVE] 1068** </ul> 1069** 1070** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1071** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1072** will be set for TEMP databases and their journals, transient 1073** databases, and subjournals. 1074** 1075** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1076** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1077** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1078** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1079** SQLITE_OPEN_CREATE, is used to indicate that file should always 1080** be created, and that it is an error if it already exists. 1081** It is <i>not</i> used to indicate the file should be opened 1082** for exclusive access. 1083** 1084** ^At least szOsFile bytes of memory are allocated by SQLite 1085** to hold the [sqlite3_file] structure passed as the third 1086** argument to xOpen. The xOpen method does not have to 1087** allocate the structure; it should just fill it in. Note that 1088** the xOpen method must set the sqlite3_file.pMethods to either 1089** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1090** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1091** element will be valid after xOpen returns regardless of the success 1092** or failure of the xOpen call. 1093** 1094** [[sqlite3_vfs.xAccess]] 1095** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1096** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1097** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1098** to test whether a file is at least readable. The file can be a 1099** directory. 1100** 1101** ^SQLite will always allocate at least mxPathname+1 bytes for the 1102** output buffer xFullPathname. The exact size of the output buffer 1103** is also passed as a parameter to both methods. If the output buffer 1104** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1105** handled as a fatal error by SQLite, vfs implementations should endeavor 1106** to prevent this by setting mxPathname to a sufficiently large value. 1107** 1108** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1109** interfaces are not strictly a part of the filesystem, but they are 1110** included in the VFS structure for completeness. 1111** The xRandomness() function attempts to return nBytes bytes 1112** of good-quality randomness into zOut. The return value is 1113** the actual number of bytes of randomness obtained. 1114** The xSleep() method causes the calling thread to sleep for at 1115** least the number of microseconds given. ^The xCurrentTime() 1116** method returns a Julian Day Number for the current date and time as 1117** a floating point value. 1118** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1119** Day Number multiplied by 86400000 (the number of milliseconds in 1120** a 24-hour day). 1121** ^SQLite will use the xCurrentTimeInt64() method to get the current 1122** date and time if that method is available (if iVersion is 2 or 1123** greater and the function pointer is not NULL) and will fall back 1124** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1125** 1126** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1127** are not used by the SQLite core. These optional interfaces are provided 1128** by some VFSes to facilitate testing of the VFS code. By overriding 1129** system calls with functions under its control, a test program can 1130** simulate faults and error conditions that would otherwise be difficult 1131** or impossible to induce. The set of system calls that can be overridden 1132** varies from one VFS to another, and from one version of the same VFS to the 1133** next. Applications that use these interfaces must be prepared for any 1134** or all of these interfaces to be NULL or for their behavior to change 1135** from one release to the next. Applications must not attempt to access 1136** any of these methods if the iVersion of the VFS is less than 3. 1137*/ 1138typedef struct sqlite3_vfs sqlite3_vfs; 1139typedef void (*sqlite3_syscall_ptr)(void); 1140struct sqlite3_vfs { 1141 int iVersion; /* Structure version number (currently 3) */ 1142 int szOsFile; /* Size of subclassed sqlite3_file */ 1143 int mxPathname; /* Maximum file pathname length */ 1144 sqlite3_vfs *pNext; /* Next registered VFS */ 1145 const char *zName; /* Name of this virtual file system */ 1146 void *pAppData; /* Pointer to application-specific data */ 1147 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1148 int flags, int *pOutFlags); 1149 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1150 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1151 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1152 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1153 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1154 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1155 void (*xDlClose)(sqlite3_vfs*, void*); 1156 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1157 int (*xSleep)(sqlite3_vfs*, int microseconds); 1158 int (*xCurrentTime)(sqlite3_vfs*, double*); 1159 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1160 /* 1161 ** The methods above are in version 1 of the sqlite_vfs object 1162 ** definition. Those that follow are added in version 2 or later 1163 */ 1164 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1165 /* 1166 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1167 ** Those below are for version 3 and greater. 1168 */ 1169 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1170 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1171 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1172 /* 1173 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1174 ** New fields may be appended in figure versions. The iVersion 1175 ** value will increment whenever this happens. 1176 */ 1177}; 1178 1179/* 1180** CAPI3REF: Flags for the xAccess VFS method 1181** 1182** These integer constants can be used as the third parameter to 1183** the xAccess method of an [sqlite3_vfs] object. They determine 1184** what kind of permissions the xAccess method is looking for. 1185** With SQLITE_ACCESS_EXISTS, the xAccess method 1186** simply checks whether the file exists. 1187** With SQLITE_ACCESS_READWRITE, the xAccess method 1188** checks whether the named directory is both readable and writable 1189** (in other words, if files can be added, removed, and renamed within 1190** the directory). 1191** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1192** [temp_store_directory pragma], though this could change in a future 1193** release of SQLite. 1194** With SQLITE_ACCESS_READ, the xAccess method 1195** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1196** currently unused, though it might be used in a future release of 1197** SQLite. 1198*/ 1199#define SQLITE_ACCESS_EXISTS 0 1200#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1201#define SQLITE_ACCESS_READ 2 /* Unused */ 1202 1203/* 1204** CAPI3REF: Flags for the xShmLock VFS method 1205** 1206** These integer constants define the various locking operations 1207** allowed by the xShmLock method of [sqlite3_io_methods]. The 1208** following are the only legal combinations of flags to the 1209** xShmLock method: 1210** 1211** <ul> 1212** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1213** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1214** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1215** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1216** </ul> 1217** 1218** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1219** was given no the corresponding lock. 1220** 1221** The xShmLock method can transition between unlocked and SHARED or 1222** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1223** and EXCLUSIVE. 1224*/ 1225#define SQLITE_SHM_UNLOCK 1 1226#define SQLITE_SHM_LOCK 2 1227#define SQLITE_SHM_SHARED 4 1228#define SQLITE_SHM_EXCLUSIVE 8 1229 1230/* 1231** CAPI3REF: Maximum xShmLock index 1232** 1233** The xShmLock method on [sqlite3_io_methods] may use values 1234** between 0 and this upper bound as its "offset" argument. 1235** The SQLite core will never attempt to acquire or release a 1236** lock outside of this range 1237*/ 1238#define SQLITE_SHM_NLOCK 8 1239 1240 1241/* 1242** CAPI3REF: Initialize The SQLite Library 1243** 1244** ^The sqlite3_initialize() routine initializes the 1245** SQLite library. ^The sqlite3_shutdown() routine 1246** deallocates any resources that were allocated by sqlite3_initialize(). 1247** These routines are designed to aid in process initialization and 1248** shutdown on embedded systems. Workstation applications using 1249** SQLite normally do not need to invoke either of these routines. 1250** 1251** A call to sqlite3_initialize() is an "effective" call if it is 1252** the first time sqlite3_initialize() is invoked during the lifetime of 1253** the process, or if it is the first time sqlite3_initialize() is invoked 1254** following a call to sqlite3_shutdown(). ^(Only an effective call 1255** of sqlite3_initialize() does any initialization. All other calls 1256** are harmless no-ops.)^ 1257** 1258** A call to sqlite3_shutdown() is an "effective" call if it is the first 1259** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1260** an effective call to sqlite3_shutdown() does any deinitialization. 1261** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1262** 1263** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1264** is not. The sqlite3_shutdown() interface must only be called from a 1265** single thread. All open [database connections] must be closed and all 1266** other SQLite resources must be deallocated prior to invoking 1267** sqlite3_shutdown(). 1268** 1269** Among other things, ^sqlite3_initialize() will invoke 1270** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1271** will invoke sqlite3_os_end(). 1272** 1273** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1274** ^If for some reason, sqlite3_initialize() is unable to initialize 1275** the library (perhaps it is unable to allocate a needed resource such 1276** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1277** 1278** ^The sqlite3_initialize() routine is called internally by many other 1279** SQLite interfaces so that an application usually does not need to 1280** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1281** calls sqlite3_initialize() so the SQLite library will be automatically 1282** initialized when [sqlite3_open()] is called if it has not be initialized 1283** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1284** compile-time option, then the automatic calls to sqlite3_initialize() 1285** are omitted and the application must call sqlite3_initialize() directly 1286** prior to using any other SQLite interface. For maximum portability, 1287** it is recommended that applications always invoke sqlite3_initialize() 1288** directly prior to using any other SQLite interface. Future releases 1289** of SQLite may require this. In other words, the behavior exhibited 1290** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1291** default behavior in some future release of SQLite. 1292** 1293** The sqlite3_os_init() routine does operating-system specific 1294** initialization of the SQLite library. The sqlite3_os_end() 1295** routine undoes the effect of sqlite3_os_init(). Typical tasks 1296** performed by these routines include allocation or deallocation 1297** of static resources, initialization of global variables, 1298** setting up a default [sqlite3_vfs] module, or setting up 1299** a default configuration using [sqlite3_config()]. 1300** 1301** The application should never invoke either sqlite3_os_init() 1302** or sqlite3_os_end() directly. The application should only invoke 1303** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1304** interface is called automatically by sqlite3_initialize() and 1305** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1306** implementations for sqlite3_os_init() and sqlite3_os_end() 1307** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1308** When [custom builds | built for other platforms] 1309** (using the [SQLITE_OS_OTHER=1] compile-time 1310** option) the application must supply a suitable implementation for 1311** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1312** implementation of sqlite3_os_init() or sqlite3_os_end() 1313** must return [SQLITE_OK] on success and some other [error code] upon 1314** failure. 1315*/ 1316int sqlite3_initialize(void); 1317int sqlite3_shutdown(void); 1318int sqlite3_os_init(void); 1319int sqlite3_os_end(void); 1320 1321/* 1322** CAPI3REF: Configuring The SQLite Library 1323** 1324** The sqlite3_config() interface is used to make global configuration 1325** changes to SQLite in order to tune SQLite to the specific needs of 1326** the application. The default configuration is recommended for most 1327** applications and so this routine is usually not necessary. It is 1328** provided to support rare applications with unusual needs. 1329** 1330** The sqlite3_config() interface is not threadsafe. The application 1331** must insure that no other SQLite interfaces are invoked by other 1332** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1333** may only be invoked prior to library initialization using 1334** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1335** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1336** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1337** Note, however, that ^sqlite3_config() can be called as part of the 1338** implementation of an application-defined [sqlite3_os_init()]. 1339** 1340** The first argument to sqlite3_config() is an integer 1341** [configuration option] that determines 1342** what property of SQLite is to be configured. Subsequent arguments 1343** vary depending on the [configuration option] 1344** in the first argument. 1345** 1346** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1347** ^If the option is unknown or SQLite is unable to set the option 1348** then this routine returns a non-zero [error code]. 1349*/ 1350int sqlite3_config(int, ...); 1351 1352/* 1353** CAPI3REF: Configure database connections 1354** 1355** The sqlite3_db_config() interface is used to make configuration 1356** changes to a [database connection]. The interface is similar to 1357** [sqlite3_config()] except that the changes apply to a single 1358** [database connection] (specified in the first argument). 1359** 1360** The second argument to sqlite3_db_config(D,V,...) is the 1361** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1362** that indicates what aspect of the [database connection] is being configured. 1363** Subsequent arguments vary depending on the configuration verb. 1364** 1365** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1366** the call is considered successful. 1367*/ 1368int sqlite3_db_config(sqlite3*, int op, ...); 1369 1370/* 1371** CAPI3REF: Memory Allocation Routines 1372** 1373** An instance of this object defines the interface between SQLite 1374** and low-level memory allocation routines. 1375** 1376** This object is used in only one place in the SQLite interface. 1377** A pointer to an instance of this object is the argument to 1378** [sqlite3_config()] when the configuration option is 1379** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1380** By creating an instance of this object 1381** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1382** during configuration, an application can specify an alternative 1383** memory allocation subsystem for SQLite to use for all of its 1384** dynamic memory needs. 1385** 1386** Note that SQLite comes with several [built-in memory allocators] 1387** that are perfectly adequate for the overwhelming majority of applications 1388** and that this object is only useful to a tiny minority of applications 1389** with specialized memory allocation requirements. This object is 1390** also used during testing of SQLite in order to specify an alternative 1391** memory allocator that simulates memory out-of-memory conditions in 1392** order to verify that SQLite recovers gracefully from such 1393** conditions. 1394** 1395** The xMalloc, xRealloc, and xFree methods must work like the 1396** malloc(), realloc() and free() functions from the standard C library. 1397** ^SQLite guarantees that the second argument to 1398** xRealloc is always a value returned by a prior call to xRoundup. 1399** 1400** xSize should return the allocated size of a memory allocation 1401** previously obtained from xMalloc or xRealloc. The allocated size 1402** is always at least as big as the requested size but may be larger. 1403** 1404** The xRoundup method returns what would be the allocated size of 1405** a memory allocation given a particular requested size. Most memory 1406** allocators round up memory allocations at least to the next multiple 1407** of 8. Some allocators round up to a larger multiple or to a power of 2. 1408** Every memory allocation request coming in through [sqlite3_malloc()] 1409** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1410** that causes the corresponding memory allocation to fail. 1411** 1412** The xInit method initializes the memory allocator. For example, 1413** it might allocate any require mutexes or initialize internal data 1414** structures. The xShutdown method is invoked (indirectly) by 1415** [sqlite3_shutdown()] and should deallocate any resources acquired 1416** by xInit. The pAppData pointer is used as the only parameter to 1417** xInit and xShutdown. 1418** 1419** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1420** the xInit method, so the xInit method need not be threadsafe. The 1421** xShutdown method is only called from [sqlite3_shutdown()] so it does 1422** not need to be threadsafe either. For all other methods, SQLite 1423** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1424** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1425** it is by default) and so the methods are automatically serialized. 1426** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1427** methods must be threadsafe or else make their own arrangements for 1428** serialization. 1429** 1430** SQLite will never invoke xInit() more than once without an intervening 1431** call to xShutdown(). 1432*/ 1433typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1434struct sqlite3_mem_methods { 1435 void *(*xMalloc)(int); /* Memory allocation function */ 1436 void (*xFree)(void*); /* Free a prior allocation */ 1437 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1438 int (*xSize)(void*); /* Return the size of an allocation */ 1439 int (*xRoundup)(int); /* Round up request size to allocation size */ 1440 int (*xInit)(void*); /* Initialize the memory allocator */ 1441 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1442 void *pAppData; /* Argument to xInit() and xShutdown() */ 1443}; 1444 1445/* 1446** CAPI3REF: Configuration Options 1447** KEYWORDS: {configuration option} 1448** 1449** These constants are the available integer configuration options that 1450** can be passed as the first argument to the [sqlite3_config()] interface. 1451** 1452** New configuration options may be added in future releases of SQLite. 1453** Existing configuration options might be discontinued. Applications 1454** should check the return code from [sqlite3_config()] to make sure that 1455** the call worked. The [sqlite3_config()] interface will return a 1456** non-zero [error code] if a discontinued or unsupported configuration option 1457** is invoked. 1458** 1459** <dl> 1460** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1461** <dd>There are no arguments to this option. ^This option sets the 1462** [threading mode] to Single-thread. In other words, it disables 1463** all mutexing and puts SQLite into a mode where it can only be used 1464** by a single thread. ^If SQLite is compiled with 1465** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1466** it is not possible to change the [threading mode] from its default 1467** value of Single-thread and so [sqlite3_config()] will return 1468** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1469** configuration option.</dd> 1470** 1471** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1472** <dd>There are no arguments to this option. ^This option sets the 1473** [threading mode] to Multi-thread. In other words, it disables 1474** mutexing on [database connection] and [prepared statement] objects. 1475** The application is responsible for serializing access to 1476** [database connections] and [prepared statements]. But other mutexes 1477** are enabled so that SQLite will be safe to use in a multi-threaded 1478** environment as long as no two threads attempt to use the same 1479** [database connection] at the same time. ^If SQLite is compiled with 1480** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1481** it is not possible to set the Multi-thread [threading mode] and 1482** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1483** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1484** 1485** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1486** <dd>There are no arguments to this option. ^This option sets the 1487** [threading mode] to Serialized. In other words, this option enables 1488** all mutexes including the recursive 1489** mutexes on [database connection] and [prepared statement] objects. 1490** In this mode (which is the default when SQLite is compiled with 1491** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1492** to [database connections] and [prepared statements] so that the 1493** application is free to use the same [database connection] or the 1494** same [prepared statement] in different threads at the same time. 1495** ^If SQLite is compiled with 1496** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1497** it is not possible to set the Serialized [threading mode] and 1498** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1499** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1500** 1501** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1502** <dd> ^(This option takes a single argument which is a pointer to an 1503** instance of the [sqlite3_mem_methods] structure. The argument specifies 1504** alternative low-level memory allocation routines to be used in place of 1505** the memory allocation routines built into SQLite.)^ ^SQLite makes 1506** its own private copy of the content of the [sqlite3_mem_methods] structure 1507** before the [sqlite3_config()] call returns.</dd> 1508** 1509** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1510** <dd> ^(This option takes a single argument which is a pointer to an 1511** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1512** structure is filled with the currently defined memory allocation routines.)^ 1513** This option can be used to overload the default memory allocation 1514** routines with a wrapper that simulations memory allocation failure or 1515** tracks memory usage, for example. </dd> 1516** 1517** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1518** <dd> ^This option takes single argument of type int, interpreted as a 1519** boolean, which enables or disables the collection of memory allocation 1520** statistics. ^(When memory allocation statistics are disabled, the 1521** following SQLite interfaces become non-operational: 1522** <ul> 1523** <li> [sqlite3_memory_used()] 1524** <li> [sqlite3_memory_highwater()] 1525** <li> [sqlite3_soft_heap_limit64()] 1526** <li> [sqlite3_status()] 1527** </ul>)^ 1528** ^Memory allocation statistics are enabled by default unless SQLite is 1529** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1530** allocation statistics are disabled by default. 1531** </dd> 1532** 1533** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1534** <dd> ^This option specifies a static memory buffer that SQLite can use for 1535** scratch memory. There are three arguments: A pointer an 8-byte 1536** aligned memory buffer from which the scratch allocations will be 1537** drawn, the size of each scratch allocation (sz), 1538** and the maximum number of scratch allocations (N). The sz 1539** argument must be a multiple of 16. 1540** The first argument must be a pointer to an 8-byte aligned buffer 1541** of at least sz*N bytes of memory. 1542** ^SQLite will use no more than two scratch buffers per thread. So 1543** N should be set to twice the expected maximum number of threads. 1544** ^SQLite will never require a scratch buffer that is more than 6 1545** times the database page size. ^If SQLite needs needs additional 1546** scratch memory beyond what is provided by this configuration option, then 1547** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1548** 1549** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1550** <dd> ^This option specifies a static memory buffer that SQLite can use for 1551** the database page cache with the default page cache implementation. 1552** This configuration should not be used if an application-define page 1553** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1554** There are three arguments to this option: A pointer to 8-byte aligned 1555** memory, the size of each page buffer (sz), and the number of pages (N). 1556** The sz argument should be the size of the largest database page 1557** (a power of two between 512 and 32768) plus a little extra for each 1558** page header. ^The page header size is 20 to 40 bytes depending on 1559** the host architecture. ^It is harmless, apart from the wasted memory, 1560** to make sz a little too large. The first 1561** argument should point to an allocation of at least sz*N bytes of memory. 1562** ^SQLite will use the memory provided by the first argument to satisfy its 1563** memory needs for the first N pages that it adds to cache. ^If additional 1564** page cache memory is needed beyond what is provided by this option, then 1565** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1566** The pointer in the first argument must 1567** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1568** will be undefined.</dd> 1569** 1570** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1571** <dd> ^This option specifies a static memory buffer that SQLite will use 1572** for all of its dynamic memory allocation needs beyond those provided 1573** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1574** There are three arguments: An 8-byte aligned pointer to the memory, 1575** the number of bytes in the memory buffer, and the minimum allocation size. 1576** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1577** to using its default memory allocator (the system malloc() implementation), 1578** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1579** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1580** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1581** allocator is engaged to handle all of SQLites memory allocation needs. 1582** The first pointer (the memory pointer) must be aligned to an 8-byte 1583** boundary or subsequent behavior of SQLite will be undefined. 1584** The minimum allocation size is capped at 2**12. Reasonable values 1585** for the minimum allocation size are 2**5 through 2**8.</dd> 1586** 1587** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1588** <dd> ^(This option takes a single argument which is a pointer to an 1589** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1590** alternative low-level mutex routines to be used in place 1591** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1592** content of the [sqlite3_mutex_methods] structure before the call to 1593** [sqlite3_config()] returns. ^If SQLite is compiled with 1594** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1595** the entire mutexing subsystem is omitted from the build and hence calls to 1596** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1597** return [SQLITE_ERROR].</dd> 1598** 1599** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1600** <dd> ^(This option takes a single argument which is a pointer to an 1601** instance of the [sqlite3_mutex_methods] structure. The 1602** [sqlite3_mutex_methods] 1603** structure is filled with the currently defined mutex routines.)^ 1604** This option can be used to overload the default mutex allocation 1605** routines with a wrapper used to track mutex usage for performance 1606** profiling or testing, for example. ^If SQLite is compiled with 1607** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1608** the entire mutexing subsystem is omitted from the build and hence calls to 1609** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1610** return [SQLITE_ERROR].</dd> 1611** 1612** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1613** <dd> ^(This option takes two arguments that determine the default 1614** memory allocation for the lookaside memory allocator on each 1615** [database connection]. The first argument is the 1616** size of each lookaside buffer slot and the second is the number of 1617** slots allocated to each database connection.)^ ^(This option sets the 1618** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1619** verb to [sqlite3_db_config()] can be used to change the lookaside 1620** configuration on individual connections.)^ </dd> 1621** 1622** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1623** <dd> ^(This option takes a single argument which is a pointer to 1624** an [sqlite3_pcache_methods2] object. This object specifies the interface 1625** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1626** object and uses it for page cache memory allocations.</dd> 1627** 1628** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1629** <dd> ^(This option takes a single argument which is a pointer to an 1630** [sqlite3_pcache_methods2] object. SQLite copies of the current 1631** page cache implementation into that object.)^ </dd> 1632** 1633** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1634** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1635** global [error log]. 1636** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1637** function with a call signature of void(*)(void*,int,const char*), 1638** and a pointer to void. ^If the function pointer is not NULL, it is 1639** invoked by [sqlite3_log()] to process each logging event. ^If the 1640** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1641** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1642** passed through as the first parameter to the application-defined logger 1643** function whenever that function is invoked. ^The second parameter to 1644** the logger function is a copy of the first parameter to the corresponding 1645** [sqlite3_log()] call and is intended to be a [result code] or an 1646** [extended result code]. ^The third parameter passed to the logger is 1647** log message after formatting via [sqlite3_snprintf()]. 1648** The SQLite logging interface is not reentrant; the logger function 1649** supplied by the application must not invoke any SQLite interface. 1650** In a multi-threaded application, the application-defined logger 1651** function must be threadsafe. </dd> 1652** 1653** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1654** <dd>^(This option takes a single argument of type int. If non-zero, then 1655** URI handling is globally enabled. If the parameter is zero, then URI handling 1656** is globally disabled.)^ ^If URI handling is globally enabled, all filenames 1657** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1658** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1659** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1660** connection is opened. ^If it is globally disabled, filenames are 1661** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1662** database connection is opened. ^(By default, URI handling is globally 1663** disabled. The default value may be changed by compiling with the 1664** [SQLITE_USE_URI] symbol defined.)^ 1665** 1666** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1667** <dd>^This option takes a single integer argument which is interpreted as 1668** a boolean in order to enable or disable the use of covering indices for 1669** full table scans in the query optimizer. ^The default setting is determined 1670** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1671** if that compile-time option is omitted. 1672** The ability to disable the use of covering indices for full table scans 1673** is because some incorrectly coded legacy applications might malfunction 1674** when the optimization is enabled. Providing the ability to 1675** disable the optimization allows the older, buggy application code to work 1676** without change even with newer versions of SQLite. 1677** 1678** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1679** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1680** <dd> These options are obsolete and should not be used by new code. 1681** They are retained for backwards compatibility but are now no-ops. 1682** </dd> 1683** 1684** [[SQLITE_CONFIG_SQLLOG]] 1685** <dt>SQLITE_CONFIG_SQLLOG 1686** <dd>This option is only available if sqlite is compiled with the 1687** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1688** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1689** The second should be of type (void*). The callback is invoked by the library 1690** in three separate circumstances, identified by the value passed as the 1691** fourth parameter. If the fourth parameter is 0, then the database connection 1692** passed as the second argument has just been opened. The third argument 1693** points to a buffer containing the name of the main database file. If the 1694** fourth parameter is 1, then the SQL statement that the third parameter 1695** points to has just been executed. Or, if the fourth parameter is 2, then 1696** the connection being passed as the second parameter is being closed. The 1697** third parameter is passed NULL In this case. An example of using this 1698** configuration option can be seen in the "test_sqllog.c" source file in 1699** the canonical SQLite source tree.</dd> 1700** 1701** [[SQLITE_CONFIG_MMAP_SIZE]] 1702** <dt>SQLITE_CONFIG_MMAP_SIZE 1703** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1704** that are the default mmap size limit (the default setting for 1705** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1706** ^The default setting can be overridden by each database connection using 1707** either the [PRAGMA mmap_size] command, or by using the 1708** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1709** cannot be changed at run-time. Nor may the maximum allowed mmap size 1710** exceed the compile-time maximum mmap size set by the 1711** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1712** ^If either argument to this option is negative, then that argument is 1713** changed to its compile-time default. 1714** 1715** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1716** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1717** <dd>^This option is only available if SQLite is compiled for Windows 1718** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. 1719** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1720** that specifies the maximum size of the created heap. 1721** </dl> 1722*/ 1723#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1724#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1725#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1726#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1727#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1728#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1729#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1730#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1731#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1732#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1733#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1734/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1735#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1736#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1737#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1738#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1739#define SQLITE_CONFIG_URI 17 /* int */ 1740#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1741#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1742#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1743#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1744#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1745#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1746 1747/* 1748** CAPI3REF: Database Connection Configuration Options 1749** 1750** These constants are the available integer configuration options that 1751** can be passed as the second argument to the [sqlite3_db_config()] interface. 1752** 1753** New configuration options may be added in future releases of SQLite. 1754** Existing configuration options might be discontinued. Applications 1755** should check the return code from [sqlite3_db_config()] to make sure that 1756** the call worked. ^The [sqlite3_db_config()] interface will return a 1757** non-zero [error code] if a discontinued or unsupported configuration option 1758** is invoked. 1759** 1760** <dl> 1761** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1762** <dd> ^This option takes three additional arguments that determine the 1763** [lookaside memory allocator] configuration for the [database connection]. 1764** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1765** pointer to a memory buffer to use for lookaside memory. 1766** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1767** may be NULL in which case SQLite will allocate the 1768** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1769** size of each lookaside buffer slot. ^The third argument is the number of 1770** slots. The size of the buffer in the first argument must be greater than 1771** or equal to the product of the second and third arguments. The buffer 1772** must be aligned to an 8-byte boundary. ^If the second argument to 1773** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1774** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1775** configuration for a database connection can only be changed when that 1776** connection is not currently using lookaside memory, or in other words 1777** when the "current value" returned by 1778** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1779** Any attempt to change the lookaside memory configuration when lookaside 1780** memory is in use leaves the configuration unchanged and returns 1781** [SQLITE_BUSY].)^</dd> 1782** 1783** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1784** <dd> ^This option is used to enable or disable the enforcement of 1785** [foreign key constraints]. There should be two additional arguments. 1786** The first argument is an integer which is 0 to disable FK enforcement, 1787** positive to enable FK enforcement or negative to leave FK enforcement 1788** unchanged. The second parameter is a pointer to an integer into which 1789** is written 0 or 1 to indicate whether FK enforcement is off or on 1790** following this call. The second parameter may be a NULL pointer, in 1791** which case the FK enforcement setting is not reported back. </dd> 1792** 1793** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1794** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1795** There should be two additional arguments. 1796** The first argument is an integer which is 0 to disable triggers, 1797** positive to enable triggers or negative to leave the setting unchanged. 1798** The second parameter is a pointer to an integer into which 1799** is written 0 or 1 to indicate whether triggers are disabled or enabled 1800** following this call. The second parameter may be a NULL pointer, in 1801** which case the trigger setting is not reported back. </dd> 1802** 1803** </dl> 1804*/ 1805#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1806#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1807#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1808 1809 1810/* 1811** CAPI3REF: Enable Or Disable Extended Result Codes 1812** 1813** ^The sqlite3_extended_result_codes() routine enables or disables the 1814** [extended result codes] feature of SQLite. ^The extended result 1815** codes are disabled by default for historical compatibility. 1816*/ 1817int sqlite3_extended_result_codes(sqlite3*, int onoff); 1818 1819/* 1820** CAPI3REF: Last Insert Rowid 1821** 1822** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1823** has a unique 64-bit signed 1824** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1825** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1826** names are not also used by explicitly declared columns. ^If 1827** the table has a column of type [INTEGER PRIMARY KEY] then that column 1828** is another alias for the rowid. 1829** 1830** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1831** most recent successful [INSERT] into a rowid table or [virtual table] 1832** on database connection D. 1833** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1834** ^If no successful [INSERT]s into rowid tables 1835** have ever occurred on the database connection D, 1836** then sqlite3_last_insert_rowid(D) returns zero. 1837** 1838** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1839** method, then this routine will return the [rowid] of the inserted 1840** row as long as the trigger or virtual table method is running. 1841** But once the trigger or virtual table method ends, the value returned 1842** by this routine reverts to what it was before the trigger or virtual 1843** table method began.)^ 1844** 1845** ^An [INSERT] that fails due to a constraint violation is not a 1846** successful [INSERT] and does not change the value returned by this 1847** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1848** and INSERT OR ABORT make no changes to the return value of this 1849** routine when their insertion fails. ^(When INSERT OR REPLACE 1850** encounters a constraint violation, it does not fail. The 1851** INSERT continues to completion after deleting rows that caused 1852** the constraint problem so INSERT OR REPLACE will always change 1853** the return value of this interface.)^ 1854** 1855** ^For the purposes of this routine, an [INSERT] is considered to 1856** be successful even if it is subsequently rolled back. 1857** 1858** This function is accessible to SQL statements via the 1859** [last_insert_rowid() SQL function]. 1860** 1861** If a separate thread performs a new [INSERT] on the same 1862** database connection while the [sqlite3_last_insert_rowid()] 1863** function is running and thus changes the last insert [rowid], 1864** then the value returned by [sqlite3_last_insert_rowid()] is 1865** unpredictable and might not equal either the old or the new 1866** last insert [rowid]. 1867*/ 1868sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1869 1870/* 1871** CAPI3REF: Count The Number Of Rows Modified 1872** 1873** ^This function returns the number of database rows that were changed 1874** or inserted or deleted by the most recently completed SQL statement 1875** on the [database connection] specified by the first parameter. 1876** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1877** or [DELETE] statement are counted. Auxiliary changes caused by 1878** triggers or [foreign key actions] are not counted.)^ Use the 1879** [sqlite3_total_changes()] function to find the total number of changes 1880** including changes caused by triggers and foreign key actions. 1881** 1882** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1883** are not counted. Only real table changes are counted. 1884** 1885** ^(A "row change" is a change to a single row of a single table 1886** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1887** are changed as side effects of [REPLACE] constraint resolution, 1888** rollback, ABORT processing, [DROP TABLE], or by any other 1889** mechanisms do not count as direct row changes.)^ 1890** 1891** A "trigger context" is a scope of execution that begins and 1892** ends with the script of a [CREATE TRIGGER | trigger]. 1893** Most SQL statements are 1894** evaluated outside of any trigger. This is the "top level" 1895** trigger context. If a trigger fires from the top level, a 1896** new trigger context is entered for the duration of that one 1897** trigger. Subtriggers create subcontexts for their duration. 1898** 1899** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1900** not create a new trigger context. 1901** 1902** ^This function returns the number of direct row changes in the 1903** most recent INSERT, UPDATE, or DELETE statement within the same 1904** trigger context. 1905** 1906** ^Thus, when called from the top level, this function returns the 1907** number of changes in the most recent INSERT, UPDATE, or DELETE 1908** that also occurred at the top level. ^(Within the body of a trigger, 1909** the sqlite3_changes() interface can be called to find the number of 1910** changes in the most recently completed INSERT, UPDATE, or DELETE 1911** statement within the body of the same trigger. 1912** However, the number returned does not include changes 1913** caused by subtriggers since those have their own context.)^ 1914** 1915** See also the [sqlite3_total_changes()] interface, the 1916** [count_changes pragma], and the [changes() SQL function]. 1917** 1918** If a separate thread makes changes on the same database connection 1919** while [sqlite3_changes()] is running then the value returned 1920** is unpredictable and not meaningful. 1921*/ 1922int sqlite3_changes(sqlite3*); 1923 1924/* 1925** CAPI3REF: Total Number Of Rows Modified 1926** 1927** ^This function returns the number of row changes caused by [INSERT], 1928** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1929** ^(The count returned by sqlite3_total_changes() includes all changes 1930** from all [CREATE TRIGGER | trigger] contexts and changes made by 1931** [foreign key actions]. However, 1932** the count does not include changes used to implement [REPLACE] constraints, 1933** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1934** count does not include rows of views that fire an [INSTEAD OF trigger], 1935** though if the INSTEAD OF trigger makes changes of its own, those changes 1936** are counted.)^ 1937** ^The sqlite3_total_changes() function counts the changes as soon as 1938** the statement that makes them is completed (when the statement handle 1939** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1940** 1941** See also the [sqlite3_changes()] interface, the 1942** [count_changes pragma], and the [total_changes() SQL function]. 1943** 1944** If a separate thread makes changes on the same database connection 1945** while [sqlite3_total_changes()] is running then the value 1946** returned is unpredictable and not meaningful. 1947*/ 1948int sqlite3_total_changes(sqlite3*); 1949 1950/* 1951** CAPI3REF: Interrupt A Long-Running Query 1952** 1953** ^This function causes any pending database operation to abort and 1954** return at its earliest opportunity. This routine is typically 1955** called in response to a user action such as pressing "Cancel" 1956** or Ctrl-C where the user wants a long query operation to halt 1957** immediately. 1958** 1959** ^It is safe to call this routine from a thread different from the 1960** thread that is currently running the database operation. But it 1961** is not safe to call this routine with a [database connection] that 1962** is closed or might close before sqlite3_interrupt() returns. 1963** 1964** ^If an SQL operation is very nearly finished at the time when 1965** sqlite3_interrupt() is called, then it might not have an opportunity 1966** to be interrupted and might continue to completion. 1967** 1968** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1969** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1970** that is inside an explicit transaction, then the entire transaction 1971** will be rolled back automatically. 1972** 1973** ^The sqlite3_interrupt(D) call is in effect until all currently running 1974** SQL statements on [database connection] D complete. ^Any new SQL statements 1975** that are started after the sqlite3_interrupt() call and before the 1976** running statements reaches zero are interrupted as if they had been 1977** running prior to the sqlite3_interrupt() call. ^New SQL statements 1978** that are started after the running statement count reaches zero are 1979** not effected by the sqlite3_interrupt(). 1980** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1981** SQL statements is a no-op and has no effect on SQL statements 1982** that are started after the sqlite3_interrupt() call returns. 1983** 1984** If the database connection closes while [sqlite3_interrupt()] 1985** is running then bad things will likely happen. 1986*/ 1987void sqlite3_interrupt(sqlite3*); 1988 1989/* 1990** CAPI3REF: Determine If An SQL Statement Is Complete 1991** 1992** These routines are useful during command-line input to determine if the 1993** currently entered text seems to form a complete SQL statement or 1994** if additional input is needed before sending the text into 1995** SQLite for parsing. ^These routines return 1 if the input string 1996** appears to be a complete SQL statement. ^A statement is judged to be 1997** complete if it ends with a semicolon token and is not a prefix of a 1998** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 1999** string literals or quoted identifier names or comments are not 2000** independent tokens (they are part of the token in which they are 2001** embedded) and thus do not count as a statement terminator. ^Whitespace 2002** and comments that follow the final semicolon are ignored. 2003** 2004** ^These routines return 0 if the statement is incomplete. ^If a 2005** memory allocation fails, then SQLITE_NOMEM is returned. 2006** 2007** ^These routines do not parse the SQL statements thus 2008** will not detect syntactically incorrect SQL. 2009** 2010** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2011** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2012** automatically by sqlite3_complete16(). If that initialization fails, 2013** then the return value from sqlite3_complete16() will be non-zero 2014** regardless of whether or not the input SQL is complete.)^ 2015** 2016** The input to [sqlite3_complete()] must be a zero-terminated 2017** UTF-8 string. 2018** 2019** The input to [sqlite3_complete16()] must be a zero-terminated 2020** UTF-16 string in native byte order. 2021*/ 2022int sqlite3_complete(const char *sql); 2023int sqlite3_complete16(const void *sql); 2024 2025/* 2026** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2027** 2028** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2029** that might be invoked with argument P whenever 2030** an attempt is made to access a database table associated with 2031** [database connection] D when another thread 2032** or process has the table locked. 2033** The sqlite3_busy_handler() interface is used to implement 2034** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2035** 2036** ^If the busy callback is NULL, then [SQLITE_BUSY] 2037** is returned immediately upon encountering the lock. ^If the busy callback 2038** is not NULL, then the callback might be invoked with two arguments. 2039** 2040** ^The first argument to the busy handler is a copy of the void* pointer which 2041** is the third argument to sqlite3_busy_handler(). ^The second argument to 2042** the busy handler callback is the number of times that the busy handler has 2043** been invoked for the same locking event. ^If the 2044** busy callback returns 0, then no additional attempts are made to 2045** access the database and [SQLITE_BUSY] is returned 2046** to the application. 2047** ^If the callback returns non-zero, then another attempt 2048** is made to access the database and the cycle repeats. 2049** 2050** The presence of a busy handler does not guarantee that it will be invoked 2051** when there is lock contention. ^If SQLite determines that invoking the busy 2052** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2053** to the application instead of invoking the 2054** busy handler. 2055** Consider a scenario where one process is holding a read lock that 2056** it is trying to promote to a reserved lock and 2057** a second process is holding a reserved lock that it is trying 2058** to promote to an exclusive lock. The first process cannot proceed 2059** because it is blocked by the second and the second process cannot 2060** proceed because it is blocked by the first. If both processes 2061** invoke the busy handlers, neither will make any progress. Therefore, 2062** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2063** will induce the first process to release its read lock and allow 2064** the second process to proceed. 2065** 2066** ^The default busy callback is NULL. 2067** 2068** ^(There can only be a single busy handler defined for each 2069** [database connection]. Setting a new busy handler clears any 2070** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2071** or evaluating [PRAGMA busy_timeout=N] will change the 2072** busy handler and thus clear any previously set busy handler. 2073** 2074** The busy callback should not take any actions which modify the 2075** database connection that invoked the busy handler. In other words, 2076** the busy handler is not reentrant. Any such actions 2077** result in undefined behavior. 2078** 2079** A busy handler must not close the database connection 2080** or [prepared statement] that invoked the busy handler. 2081*/ 2082int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2083 2084/* 2085** CAPI3REF: Set A Busy Timeout 2086** 2087** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2088** for a specified amount of time when a table is locked. ^The handler 2089** will sleep multiple times until at least "ms" milliseconds of sleeping 2090** have accumulated. ^After at least "ms" milliseconds of sleeping, 2091** the handler returns 0 which causes [sqlite3_step()] to return 2092** [SQLITE_BUSY]. 2093** 2094** ^Calling this routine with an argument less than or equal to zero 2095** turns off all busy handlers. 2096** 2097** ^(There can only be a single busy handler for a particular 2098** [database connection] at any given moment. If another busy handler 2099** was defined (using [sqlite3_busy_handler()]) prior to calling 2100** this routine, that other busy handler is cleared.)^ 2101** 2102** See also: [PRAGMA busy_timeout] 2103*/ 2104int sqlite3_busy_timeout(sqlite3*, int ms); 2105 2106/* 2107** CAPI3REF: Convenience Routines For Running Queries 2108** 2109** This is a legacy interface that is preserved for backwards compatibility. 2110** Use of this interface is not recommended. 2111** 2112** Definition: A <b>result table</b> is memory data structure created by the 2113** [sqlite3_get_table()] interface. A result table records the 2114** complete query results from one or more queries. 2115** 2116** The table conceptually has a number of rows and columns. But 2117** these numbers are not part of the result table itself. These 2118** numbers are obtained separately. Let N be the number of rows 2119** and M be the number of columns. 2120** 2121** A result table is an array of pointers to zero-terminated UTF-8 strings. 2122** There are (N+1)*M elements in the array. The first M pointers point 2123** to zero-terminated strings that contain the names of the columns. 2124** The remaining entries all point to query results. NULL values result 2125** in NULL pointers. All other values are in their UTF-8 zero-terminated 2126** string representation as returned by [sqlite3_column_text()]. 2127** 2128** A result table might consist of one or more memory allocations. 2129** It is not safe to pass a result table directly to [sqlite3_free()]. 2130** A result table should be deallocated using [sqlite3_free_table()]. 2131** 2132** ^(As an example of the result table format, suppose a query result 2133** is as follows: 2134** 2135** <blockquote><pre> 2136** Name | Age 2137** ----------------------- 2138** Alice | 43 2139** Bob | 28 2140** Cindy | 21 2141** </pre></blockquote> 2142** 2143** There are two column (M==2) and three rows (N==3). Thus the 2144** result table has 8 entries. Suppose the result table is stored 2145** in an array names azResult. Then azResult holds this content: 2146** 2147** <blockquote><pre> 2148** azResult[0] = "Name"; 2149** azResult[1] = "Age"; 2150** azResult[2] = "Alice"; 2151** azResult[3] = "43"; 2152** azResult[4] = "Bob"; 2153** azResult[5] = "28"; 2154** azResult[6] = "Cindy"; 2155** azResult[7] = "21"; 2156** </pre></blockquote>)^ 2157** 2158** ^The sqlite3_get_table() function evaluates one or more 2159** semicolon-separated SQL statements in the zero-terminated UTF-8 2160** string of its 2nd parameter and returns a result table to the 2161** pointer given in its 3rd parameter. 2162** 2163** After the application has finished with the result from sqlite3_get_table(), 2164** it must pass the result table pointer to sqlite3_free_table() in order to 2165** release the memory that was malloced. Because of the way the 2166** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2167** function must not try to call [sqlite3_free()] directly. Only 2168** [sqlite3_free_table()] is able to release the memory properly and safely. 2169** 2170** The sqlite3_get_table() interface is implemented as a wrapper around 2171** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2172** to any internal data structures of SQLite. It uses only the public 2173** interface defined here. As a consequence, errors that occur in the 2174** wrapper layer outside of the internal [sqlite3_exec()] call are not 2175** reflected in subsequent calls to [sqlite3_errcode()] or 2176** [sqlite3_errmsg()]. 2177*/ 2178int sqlite3_get_table( 2179 sqlite3 *db, /* An open database */ 2180 const char *zSql, /* SQL to be evaluated */ 2181 char ***pazResult, /* Results of the query */ 2182 int *pnRow, /* Number of result rows written here */ 2183 int *pnColumn, /* Number of result columns written here */ 2184 char **pzErrmsg /* Error msg written here */ 2185); 2186void sqlite3_free_table(char **result); 2187 2188/* 2189** CAPI3REF: Formatted String Printing Functions 2190** 2191** These routines are work-alikes of the "printf()" family of functions 2192** from the standard C library. 2193** 2194** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2195** results into memory obtained from [sqlite3_malloc()]. 2196** The strings returned by these two routines should be 2197** released by [sqlite3_free()]. ^Both routines return a 2198** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2199** memory to hold the resulting string. 2200** 2201** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2202** the standard C library. The result is written into the 2203** buffer supplied as the second parameter whose size is given by 2204** the first parameter. Note that the order of the 2205** first two parameters is reversed from snprintf().)^ This is an 2206** historical accident that cannot be fixed without breaking 2207** backwards compatibility. ^(Note also that sqlite3_snprintf() 2208** returns a pointer to its buffer instead of the number of 2209** characters actually written into the buffer.)^ We admit that 2210** the number of characters written would be a more useful return 2211** value but we cannot change the implementation of sqlite3_snprintf() 2212** now without breaking compatibility. 2213** 2214** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2215** guarantees that the buffer is always zero-terminated. ^The first 2216** parameter "n" is the total size of the buffer, including space for 2217** the zero terminator. So the longest string that can be completely 2218** written will be n-1 characters. 2219** 2220** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2221** 2222** These routines all implement some additional formatting 2223** options that are useful for constructing SQL statements. 2224** All of the usual printf() formatting options apply. In addition, there 2225** is are "%q", "%Q", and "%z" options. 2226** 2227** ^(The %q option works like %s in that it substitutes a nul-terminated 2228** string from the argument list. But %q also doubles every '\'' character. 2229** %q is designed for use inside a string literal.)^ By doubling each '\'' 2230** character it escapes that character and allows it to be inserted into 2231** the string. 2232** 2233** For example, assume the string variable zText contains text as follows: 2234** 2235** <blockquote><pre> 2236** char *zText = "It's a happy day!"; 2237** </pre></blockquote> 2238** 2239** One can use this text in an SQL statement as follows: 2240** 2241** <blockquote><pre> 2242** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2243** sqlite3_exec(db, zSQL, 0, 0, 0); 2244** sqlite3_free(zSQL); 2245** </pre></blockquote> 2246** 2247** Because the %q format string is used, the '\'' character in zText 2248** is escaped and the SQL generated is as follows: 2249** 2250** <blockquote><pre> 2251** INSERT INTO table1 VALUES('It''s a happy day!') 2252** </pre></blockquote> 2253** 2254** This is correct. Had we used %s instead of %q, the generated SQL 2255** would have looked like this: 2256** 2257** <blockquote><pre> 2258** INSERT INTO table1 VALUES('It's a happy day!'); 2259** </pre></blockquote> 2260** 2261** This second example is an SQL syntax error. As a general rule you should 2262** always use %q instead of %s when inserting text into a string literal. 2263** 2264** ^(The %Q option works like %q except it also adds single quotes around 2265** the outside of the total string. Additionally, if the parameter in the 2266** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2267** single quotes).)^ So, for example, one could say: 2268** 2269** <blockquote><pre> 2270** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2271** sqlite3_exec(db, zSQL, 0, 0, 0); 2272** sqlite3_free(zSQL); 2273** </pre></blockquote> 2274** 2275** The code above will render a correct SQL statement in the zSQL 2276** variable even if the zText variable is a NULL pointer. 2277** 2278** ^(The "%z" formatting option works like "%s" but with the 2279** addition that after the string has been read and copied into 2280** the result, [sqlite3_free()] is called on the input string.)^ 2281*/ 2282char *sqlite3_mprintf(const char*,...); 2283char *sqlite3_vmprintf(const char*, va_list); 2284char *sqlite3_snprintf(int,char*,const char*, ...); 2285char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2286 2287/* 2288** CAPI3REF: Memory Allocation Subsystem 2289** 2290** The SQLite core uses these three routines for all of its own 2291** internal memory allocation needs. "Core" in the previous sentence 2292** does not include operating-system specific VFS implementation. The 2293** Windows VFS uses native malloc() and free() for some operations. 2294** 2295** ^The sqlite3_malloc() routine returns a pointer to a block 2296** of memory at least N bytes in length, where N is the parameter. 2297** ^If sqlite3_malloc() is unable to obtain sufficient free 2298** memory, it returns a NULL pointer. ^If the parameter N to 2299** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2300** a NULL pointer. 2301** 2302** ^Calling sqlite3_free() with a pointer previously returned 2303** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2304** that it might be reused. ^The sqlite3_free() routine is 2305** a no-op if is called with a NULL pointer. Passing a NULL pointer 2306** to sqlite3_free() is harmless. After being freed, memory 2307** should neither be read nor written. Even reading previously freed 2308** memory might result in a segmentation fault or other severe error. 2309** Memory corruption, a segmentation fault, or other severe error 2310** might result if sqlite3_free() is called with a non-NULL pointer that 2311** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2312** 2313** ^(The sqlite3_realloc() interface attempts to resize a 2314** prior memory allocation to be at least N bytes, where N is the 2315** second parameter. The memory allocation to be resized is the first 2316** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2317** is a NULL pointer then its behavior is identical to calling 2318** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2319** ^If the second parameter to sqlite3_realloc() is zero or 2320** negative then the behavior is exactly the same as calling 2321** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2322** ^sqlite3_realloc() returns a pointer to a memory allocation 2323** of at least N bytes in size or NULL if sufficient memory is unavailable. 2324** ^If M is the size of the prior allocation, then min(N,M) bytes 2325** of the prior allocation are copied into the beginning of buffer returned 2326** by sqlite3_realloc() and the prior allocation is freed. 2327** ^If sqlite3_realloc() returns NULL, then the prior allocation 2328** is not freed. 2329** 2330** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2331** is always aligned to at least an 8 byte boundary, or to a 2332** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2333** option is used. 2334** 2335** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2336** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2337** implementation of these routines to be omitted. That capability 2338** is no longer provided. Only built-in memory allocators can be used. 2339** 2340** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2341** the system malloc() and free() directly when converting 2342** filenames between the UTF-8 encoding used by SQLite 2343** and whatever filename encoding is used by the particular Windows 2344** installation. Memory allocation errors were detected, but 2345** they were reported back as [SQLITE_CANTOPEN] or 2346** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2347** 2348** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2349** must be either NULL or else pointers obtained from a prior 2350** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2351** not yet been released. 2352** 2353** The application must not read or write any part of 2354** a block of memory after it has been released using 2355** [sqlite3_free()] or [sqlite3_realloc()]. 2356*/ 2357void *sqlite3_malloc(int); 2358void *sqlite3_realloc(void*, int); 2359void sqlite3_free(void*); 2360 2361/* 2362** CAPI3REF: Memory Allocator Statistics 2363** 2364** SQLite provides these two interfaces for reporting on the status 2365** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2366** routines, which form the built-in memory allocation subsystem. 2367** 2368** ^The [sqlite3_memory_used()] routine returns the number of bytes 2369** of memory currently outstanding (malloced but not freed). 2370** ^The [sqlite3_memory_highwater()] routine returns the maximum 2371** value of [sqlite3_memory_used()] since the high-water mark 2372** was last reset. ^The values returned by [sqlite3_memory_used()] and 2373** [sqlite3_memory_highwater()] include any overhead 2374** added by SQLite in its implementation of [sqlite3_malloc()], 2375** but not overhead added by the any underlying system library 2376** routines that [sqlite3_malloc()] may call. 2377** 2378** ^The memory high-water mark is reset to the current value of 2379** [sqlite3_memory_used()] if and only if the parameter to 2380** [sqlite3_memory_highwater()] is true. ^The value returned 2381** by [sqlite3_memory_highwater(1)] is the high-water mark 2382** prior to the reset. 2383*/ 2384sqlite3_int64 sqlite3_memory_used(void); 2385sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2386 2387/* 2388** CAPI3REF: Pseudo-Random Number Generator 2389** 2390** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2391** select random [ROWID | ROWIDs] when inserting new records into a table that 2392** already uses the largest possible [ROWID]. The PRNG is also used for 2393** the build-in random() and randomblob() SQL functions. This interface allows 2394** applications to access the same PRNG for other purposes. 2395** 2396** ^A call to this routine stores N bytes of randomness into buffer P. 2397** ^If N is less than one, then P can be a NULL pointer. 2398** 2399** ^If this routine has not been previously called or if the previous 2400** call had N less than one, then the PRNG is seeded using randomness 2401** obtained from the xRandomness method of the default [sqlite3_vfs] object. 2402** ^If the previous call to this routine had an N of 1 or more then 2403** the pseudo-randomness is generated 2404** internally and without recourse to the [sqlite3_vfs] xRandomness 2405** method. 2406*/ 2407void sqlite3_randomness(int N, void *P); 2408 2409/* 2410** CAPI3REF: Compile-Time Authorization Callbacks 2411** 2412** ^This routine registers an authorizer callback with a particular 2413** [database connection], supplied in the first argument. 2414** ^The authorizer callback is invoked as SQL statements are being compiled 2415** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2416** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2417** points during the compilation process, as logic is being created 2418** to perform various actions, the authorizer callback is invoked to 2419** see if those actions are allowed. ^The authorizer callback should 2420** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2421** specific action but allow the SQL statement to continue to be 2422** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2423** rejected with an error. ^If the authorizer callback returns 2424** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2425** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2426** the authorizer will fail with an error message. 2427** 2428** When the callback returns [SQLITE_OK], that means the operation 2429** requested is ok. ^When the callback returns [SQLITE_DENY], the 2430** [sqlite3_prepare_v2()] or equivalent call that triggered the 2431** authorizer will fail with an error message explaining that 2432** access is denied. 2433** 2434** ^The first parameter to the authorizer callback is a copy of the third 2435** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2436** to the callback is an integer [SQLITE_COPY | action code] that specifies 2437** the particular action to be authorized. ^The third through sixth parameters 2438** to the callback are zero-terminated strings that contain additional 2439** details about the action to be authorized. 2440** 2441** ^If the action code is [SQLITE_READ] 2442** and the callback returns [SQLITE_IGNORE] then the 2443** [prepared statement] statement is constructed to substitute 2444** a NULL value in place of the table column that would have 2445** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2446** return can be used to deny an untrusted user access to individual 2447** columns of a table. 2448** ^If the action code is [SQLITE_DELETE] and the callback returns 2449** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2450** [truncate optimization] is disabled and all rows are deleted individually. 2451** 2452** An authorizer is used when [sqlite3_prepare | preparing] 2453** SQL statements from an untrusted source, to ensure that the SQL statements 2454** do not try to access data they are not allowed to see, or that they do not 2455** try to execute malicious statements that damage the database. For 2456** example, an application may allow a user to enter arbitrary 2457** SQL queries for evaluation by a database. But the application does 2458** not want the user to be able to make arbitrary changes to the 2459** database. An authorizer could then be put in place while the 2460** user-entered SQL is being [sqlite3_prepare | prepared] that 2461** disallows everything except [SELECT] statements. 2462** 2463** Applications that need to process SQL from untrusted sources 2464** might also consider lowering resource limits using [sqlite3_limit()] 2465** and limiting database size using the [max_page_count] [PRAGMA] 2466** in addition to using an authorizer. 2467** 2468** ^(Only a single authorizer can be in place on a database connection 2469** at a time. Each call to sqlite3_set_authorizer overrides the 2470** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2471** The authorizer is disabled by default. 2472** 2473** The authorizer callback must not do anything that will modify 2474** the database connection that invoked the authorizer callback. 2475** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2476** database connections for the meaning of "modify" in this paragraph. 2477** 2478** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2479** statement might be re-prepared during [sqlite3_step()] due to a 2480** schema change. Hence, the application should ensure that the 2481** correct authorizer callback remains in place during the [sqlite3_step()]. 2482** 2483** ^Note that the authorizer callback is invoked only during 2484** [sqlite3_prepare()] or its variants. Authorization is not 2485** performed during statement evaluation in [sqlite3_step()], unless 2486** as stated in the previous paragraph, sqlite3_step() invokes 2487** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2488*/ 2489int sqlite3_set_authorizer( 2490 sqlite3*, 2491 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2492 void *pUserData 2493); 2494 2495/* 2496** CAPI3REF: Authorizer Return Codes 2497** 2498** The [sqlite3_set_authorizer | authorizer callback function] must 2499** return either [SQLITE_OK] or one of these two constants in order 2500** to signal SQLite whether or not the action is permitted. See the 2501** [sqlite3_set_authorizer | authorizer documentation] for additional 2502** information. 2503** 2504** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2505** returned from the [sqlite3_vtab_on_conflict()] interface. 2506*/ 2507#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2508#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2509 2510/* 2511** CAPI3REF: Authorizer Action Codes 2512** 2513** The [sqlite3_set_authorizer()] interface registers a callback function 2514** that is invoked to authorize certain SQL statement actions. The 2515** second parameter to the callback is an integer code that specifies 2516** what action is being authorized. These are the integer action codes that 2517** the authorizer callback may be passed. 2518** 2519** These action code values signify what kind of operation is to be 2520** authorized. The 3rd and 4th parameters to the authorization 2521** callback function will be parameters or NULL depending on which of these 2522** codes is used as the second parameter. ^(The 5th parameter to the 2523** authorizer callback is the name of the database ("main", "temp", 2524** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2525** is the name of the inner-most trigger or view that is responsible for 2526** the access attempt or NULL if this access attempt is directly from 2527** top-level SQL code. 2528*/ 2529/******************************************* 3rd ************ 4th ***********/ 2530#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2531#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2532#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2533#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2534#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2535#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2536#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2537#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2538#define SQLITE_DELETE 9 /* Table Name NULL */ 2539#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2540#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2541#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2542#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2543#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2544#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2545#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2546#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2547#define SQLITE_INSERT 18 /* Table Name NULL */ 2548#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2549#define SQLITE_READ 20 /* Table Name Column Name */ 2550#define SQLITE_SELECT 21 /* NULL NULL */ 2551#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2552#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2553#define SQLITE_ATTACH 24 /* Filename NULL */ 2554#define SQLITE_DETACH 25 /* Database Name NULL */ 2555#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2556#define SQLITE_REINDEX 27 /* Index Name NULL */ 2557#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2558#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2559#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2560#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2561#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2562#define SQLITE_COPY 0 /* No longer used */ 2563#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2564 2565/* 2566** CAPI3REF: Tracing And Profiling Functions 2567** 2568** These routines register callback functions that can be used for 2569** tracing and profiling the execution of SQL statements. 2570** 2571** ^The callback function registered by sqlite3_trace() is invoked at 2572** various times when an SQL statement is being run by [sqlite3_step()]. 2573** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2574** SQL statement text as the statement first begins executing. 2575** ^(Additional sqlite3_trace() callbacks might occur 2576** as each triggered subprogram is entered. The callbacks for triggers 2577** contain a UTF-8 SQL comment that identifies the trigger.)^ 2578** 2579** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2580** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2581** 2582** ^The callback function registered by sqlite3_profile() is invoked 2583** as each SQL statement finishes. ^The profile callback contains 2584** the original statement text and an estimate of wall-clock time 2585** of how long that statement took to run. ^The profile callback 2586** time is in units of nanoseconds, however the current implementation 2587** is only capable of millisecond resolution so the six least significant 2588** digits in the time are meaningless. Future versions of SQLite 2589** might provide greater resolution on the profiler callback. The 2590** sqlite3_profile() function is considered experimental and is 2591** subject to change in future versions of SQLite. 2592*/ 2593void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2594SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2595 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2596 2597/* 2598** CAPI3REF: Query Progress Callbacks 2599** 2600** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2601** function X to be invoked periodically during long running calls to 2602** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2603** database connection D. An example use for this 2604** interface is to keep a GUI updated during a large query. 2605** 2606** ^The parameter P is passed through as the only parameter to the 2607** callback function X. ^The parameter N is the approximate number of 2608** [virtual machine instructions] that are evaluated between successive 2609** invocations of the callback X. ^If N is less than one then the progress 2610** handler is disabled. 2611** 2612** ^Only a single progress handler may be defined at one time per 2613** [database connection]; setting a new progress handler cancels the 2614** old one. ^Setting parameter X to NULL disables the progress handler. 2615** ^The progress handler is also disabled by setting N to a value less 2616** than 1. 2617** 2618** ^If the progress callback returns non-zero, the operation is 2619** interrupted. This feature can be used to implement a 2620** "Cancel" button on a GUI progress dialog box. 2621** 2622** The progress handler callback must not do anything that will modify 2623** the database connection that invoked the progress handler. 2624** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2625** database connections for the meaning of "modify" in this paragraph. 2626** 2627*/ 2628void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2629 2630/* 2631** CAPI3REF: Opening A New Database Connection 2632** 2633** ^These routines open an SQLite database file as specified by the 2634** filename argument. ^The filename argument is interpreted as UTF-8 for 2635** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2636** order for sqlite3_open16(). ^(A [database connection] handle is usually 2637** returned in *ppDb, even if an error occurs. The only exception is that 2638** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2639** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2640** object.)^ ^(If the database is opened (and/or created) successfully, then 2641** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2642** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2643** an English language description of the error following a failure of any 2644** of the sqlite3_open() routines. 2645** 2646** ^The default encoding for the database will be UTF-8 if 2647** sqlite3_open() or sqlite3_open_v2() is called and 2648** UTF-16 in the native byte order if sqlite3_open16() is used. 2649** 2650** Whether or not an error occurs when it is opened, resources 2651** associated with the [database connection] handle should be released by 2652** passing it to [sqlite3_close()] when it is no longer required. 2653** 2654** The sqlite3_open_v2() interface works like sqlite3_open() 2655** except that it accepts two additional parameters for additional control 2656** over the new database connection. ^(The flags parameter to 2657** sqlite3_open_v2() can take one of 2658** the following three values, optionally combined with the 2659** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2660** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2661** 2662** <dl> 2663** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2664** <dd>The database is opened in read-only mode. If the database does not 2665** already exist, an error is returned.</dd>)^ 2666** 2667** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2668** <dd>The database is opened for reading and writing if possible, or reading 2669** only if the file is write protected by the operating system. In either 2670** case the database must already exist, otherwise an error is returned.</dd>)^ 2671** 2672** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2673** <dd>The database is opened for reading and writing, and is created if 2674** it does not already exist. This is the behavior that is always used for 2675** sqlite3_open() and sqlite3_open16().</dd>)^ 2676** </dl> 2677** 2678** If the 3rd parameter to sqlite3_open_v2() is not one of the 2679** combinations shown above optionally combined with other 2680** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2681** then the behavior is undefined. 2682** 2683** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2684** opens in the multi-thread [threading mode] as long as the single-thread 2685** mode has not been set at compile-time or start-time. ^If the 2686** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2687** in the serialized [threading mode] unless single-thread was 2688** previously selected at compile-time or start-time. 2689** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2690** eligible to use [shared cache mode], regardless of whether or not shared 2691** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2692** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2693** participate in [shared cache mode] even if it is enabled. 2694** 2695** ^The fourth parameter to sqlite3_open_v2() is the name of the 2696** [sqlite3_vfs] object that defines the operating system interface that 2697** the new database connection should use. ^If the fourth parameter is 2698** a NULL pointer then the default [sqlite3_vfs] object is used. 2699** 2700** ^If the filename is ":memory:", then a private, temporary in-memory database 2701** is created for the connection. ^This in-memory database will vanish when 2702** the database connection is closed. Future versions of SQLite might 2703** make use of additional special filenames that begin with the ":" character. 2704** It is recommended that when a database filename actually does begin with 2705** a ":" character you should prefix the filename with a pathname such as 2706** "./" to avoid ambiguity. 2707** 2708** ^If the filename is an empty string, then a private, temporary 2709** on-disk database will be created. ^This private database will be 2710** automatically deleted as soon as the database connection is closed. 2711** 2712** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2713** 2714** ^If [URI filename] interpretation is enabled, and the filename argument 2715** begins with "file:", then the filename is interpreted as a URI. ^URI 2716** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2717** set in the fourth argument to sqlite3_open_v2(), or if it has 2718** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2719** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2720** As of SQLite version 3.7.7, URI filename interpretation is turned off 2721** by default, but future releases of SQLite might enable URI filename 2722** interpretation by default. See "[URI filenames]" for additional 2723** information. 2724** 2725** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2726** authority, then it must be either an empty string or the string 2727** "localhost". ^If the authority is not an empty string or "localhost", an 2728** error is returned to the caller. ^The fragment component of a URI, if 2729** present, is ignored. 2730** 2731** ^SQLite uses the path component of the URI as the name of the disk file 2732** which contains the database. ^If the path begins with a '/' character, 2733** then it is interpreted as an absolute path. ^If the path does not begin 2734** with a '/' (meaning that the authority section is omitted from the URI) 2735** then the path is interpreted as a relative path. 2736** ^On windows, the first component of an absolute path 2737** is a drive specification (e.g. "C:"). 2738** 2739** [[core URI query parameters]] 2740** The query component of a URI may contain parameters that are interpreted 2741** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2742** SQLite interprets the following three query parameters: 2743** 2744** <ul> 2745** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2746** a VFS object that provides the operating system interface that should 2747** be used to access the database file on disk. ^If this option is set to 2748** an empty string the default VFS object is used. ^Specifying an unknown 2749** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2750** present, then the VFS specified by the option takes precedence over 2751** the value passed as the fourth parameter to sqlite3_open_v2(). 2752** 2753** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2754** "rwc", or "memory". Attempting to set it to any other value is 2755** an error)^. 2756** ^If "ro" is specified, then the database is opened for read-only 2757** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2758** third argument to sqlite3_open_v2(). ^If the mode option is set to 2759** "rw", then the database is opened for read-write (but not create) 2760** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2761** been set. ^Value "rwc" is equivalent to setting both 2762** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2763** set to "memory" then a pure [in-memory database] that never reads 2764** or writes from disk is used. ^It is an error to specify a value for 2765** the mode parameter that is less restrictive than that specified by 2766** the flags passed in the third parameter to sqlite3_open_v2(). 2767** 2768** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2769** "private". ^Setting it to "shared" is equivalent to setting the 2770** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2771** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2772** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2773** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2774** a URI filename, its value overrides any behavior requested by setting 2775** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2776** 2777** <li> <b>psow</b>: ^The psow parameter may be "true" (or "on" or "yes" or 2778** "1") or "false" (or "off" or "no" or "0") to indicate that the 2779** [powersafe overwrite] property does or does not apply to the 2780** storage media on which the database file resides. ^The psow query 2781** parameter only works for the built-in unix and Windows VFSes. 2782** 2783** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2784** which if set disables file locking in rollback journal modes. This 2785** is useful for accessing a database on a filesystem that does not 2786** support locking. Caution: Database corruption might result if two 2787** or more processes write to the same database and any one of those 2788** processes uses nolock=1. 2789** 2790** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2791** parameter that indicates that the database file is stored on 2792** read-only media. ^When immutable is set, SQLite assumes that the 2793** database file cannot be changed, even by a process with higher 2794** privilege, and so the database is opened read-only and all locking 2795** and change detection is disabled. Caution: Setting the immutable 2796** property on a database file that does in fact change can result 2797** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2798** See also: [SQLITE_IOCAP_IMMUTABLE]. 2799** 2800** </ul> 2801** 2802** ^Specifying an unknown parameter in the query component of a URI is not an 2803** error. Future versions of SQLite might understand additional query 2804** parameters. See "[query parameters with special meaning to SQLite]" for 2805** additional information. 2806** 2807** [[URI filename examples]] <h3>URI filename examples</h3> 2808** 2809** <table border="1" align=center cellpadding=5> 2810** <tr><th> URI filenames <th> Results 2811** <tr><td> file:data.db <td> 2812** Open the file "data.db" in the current directory. 2813** <tr><td> file:/home/fred/data.db<br> 2814** file:///home/fred/data.db <br> 2815** file://localhost/home/fred/data.db <br> <td> 2816** Open the database file "/home/fred/data.db". 2817** <tr><td> file://darkstar/home/fred/data.db <td> 2818** An error. "darkstar" is not a recognized authority. 2819** <tr><td style="white-space:nowrap"> 2820** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2821** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2822** C:. Note that the %20 escaping in this example is not strictly 2823** necessary - space characters can be used literally 2824** in URI filenames. 2825** <tr><td> file:data.db?mode=ro&cache=private <td> 2826** Open file "data.db" in the current directory for read-only access. 2827** Regardless of whether or not shared-cache mode is enabled by 2828** default, use a private cache. 2829** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2830** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2831** that uses dot-files in place of posix advisory locking. 2832** <tr><td> file:data.db?mode=readonly <td> 2833** An error. "readonly" is not a valid option for the "mode" parameter. 2834** </table> 2835** 2836** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2837** query components of a URI. A hexadecimal escape sequence consists of a 2838** percent sign - "%" - followed by exactly two hexadecimal digits 2839** specifying an octet value. ^Before the path or query components of a 2840** URI filename are interpreted, they are encoded using UTF-8 and all 2841** hexadecimal escape sequences replaced by a single byte containing the 2842** corresponding octet. If this process generates an invalid UTF-8 encoding, 2843** the results are undefined. 2844** 2845** <b>Note to Windows users:</b> The encoding used for the filename argument 2846** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2847** codepage is currently defined. Filenames containing international 2848** characters must be converted to UTF-8 prior to passing them into 2849** sqlite3_open() or sqlite3_open_v2(). 2850** 2851** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2852** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2853** features that require the use of temporary files may fail. 2854** 2855** See also: [sqlite3_temp_directory] 2856*/ 2857int sqlite3_open( 2858 const char *filename, /* Database filename (UTF-8) */ 2859 sqlite3 **ppDb /* OUT: SQLite db handle */ 2860); 2861int sqlite3_open16( 2862 const void *filename, /* Database filename (UTF-16) */ 2863 sqlite3 **ppDb /* OUT: SQLite db handle */ 2864); 2865int sqlite3_open_v2( 2866 const char *filename, /* Database filename (UTF-8) */ 2867 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2868 int flags, /* Flags */ 2869 const char *zVfs /* Name of VFS module to use */ 2870); 2871 2872/* 2873** CAPI3REF: Obtain Values For URI Parameters 2874** 2875** These are utility routines, useful to VFS implementations, that check 2876** to see if a database file was a URI that contained a specific query 2877** parameter, and if so obtains the value of that query parameter. 2878** 2879** If F is the database filename pointer passed into the xOpen() method of 2880** a VFS implementation when the flags parameter to xOpen() has one or 2881** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2882** P is the name of the query parameter, then 2883** sqlite3_uri_parameter(F,P) returns the value of the P 2884** parameter if it exists or a NULL pointer if P does not appear as a 2885** query parameter on F. If P is a query parameter of F 2886** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2887** a pointer to an empty string. 2888** 2889** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2890** parameter and returns true (1) or false (0) according to the value 2891** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2892** value of query parameter P is one of "yes", "true", or "on" in any 2893** case or if the value begins with a non-zero number. The 2894** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2895** query parameter P is one of "no", "false", or "off" in any case or 2896** if the value begins with a numeric zero. If P is not a query 2897** parameter on F or if the value of P is does not match any of the 2898** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2899** 2900** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2901** 64-bit signed integer and returns that integer, or D if P does not 2902** exist. If the value of P is something other than an integer, then 2903** zero is returned. 2904** 2905** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2906** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2907** is not a database file pathname pointer that SQLite passed into the xOpen 2908** VFS method, then the behavior of this routine is undefined and probably 2909** undesirable. 2910*/ 2911const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2912int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2913sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2914 2915 2916/* 2917** CAPI3REF: Error Codes And Messages 2918** 2919** ^The sqlite3_errcode() interface returns the numeric [result code] or 2920** [extended result code] for the most recent failed sqlite3_* API call 2921** associated with a [database connection]. If a prior API call failed 2922** but the most recent API call succeeded, the return value from 2923** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2924** interface is the same except that it always returns the 2925** [extended result code] even when extended result codes are 2926** disabled. 2927** 2928** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2929** text that describes the error, as either UTF-8 or UTF-16 respectively. 2930** ^(Memory to hold the error message string is managed internally. 2931** The application does not need to worry about freeing the result. 2932** However, the error string might be overwritten or deallocated by 2933** subsequent calls to other SQLite interface functions.)^ 2934** 2935** ^The sqlite3_errstr() interface returns the English-language text 2936** that describes the [result code], as UTF-8. 2937** ^(Memory to hold the error message string is managed internally 2938** and must not be freed by the application)^. 2939** 2940** When the serialized [threading mode] is in use, it might be the 2941** case that a second error occurs on a separate thread in between 2942** the time of the first error and the call to these interfaces. 2943** When that happens, the second error will be reported since these 2944** interfaces always report the most recent result. To avoid 2945** this, each thread can obtain exclusive use of the [database connection] D 2946** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2947** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2948** all calls to the interfaces listed here are completed. 2949** 2950** If an interface fails with SQLITE_MISUSE, that means the interface 2951** was invoked incorrectly by the application. In that case, the 2952** error code and message may or may not be set. 2953*/ 2954int sqlite3_errcode(sqlite3 *db); 2955int sqlite3_extended_errcode(sqlite3 *db); 2956const char *sqlite3_errmsg(sqlite3*); 2957const void *sqlite3_errmsg16(sqlite3*); 2958const char *sqlite3_errstr(int); 2959 2960/* 2961** CAPI3REF: SQL Statement Object 2962** KEYWORDS: {prepared statement} {prepared statements} 2963** 2964** An instance of this object represents a single SQL statement. 2965** This object is variously known as a "prepared statement" or a 2966** "compiled SQL statement" or simply as a "statement". 2967** 2968** The life of a statement object goes something like this: 2969** 2970** <ol> 2971** <li> Create the object using [sqlite3_prepare_v2()] or a related 2972** function. 2973** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2974** interfaces. 2975** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2976** <li> Reset the statement using [sqlite3_reset()] then go back 2977** to step 2. Do this zero or more times. 2978** <li> Destroy the object using [sqlite3_finalize()]. 2979** </ol> 2980** 2981** Refer to documentation on individual methods above for additional 2982** information. 2983*/ 2984typedef struct sqlite3_stmt sqlite3_stmt; 2985 2986/* 2987** CAPI3REF: Run-time Limits 2988** 2989** ^(This interface allows the size of various constructs to be limited 2990** on a connection by connection basis. The first parameter is the 2991** [database connection] whose limit is to be set or queried. The 2992** second parameter is one of the [limit categories] that define a 2993** class of constructs to be size limited. The third parameter is the 2994** new limit for that construct.)^ 2995** 2996** ^If the new limit is a negative number, the limit is unchanged. 2997** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2998** [limits | hard upper bound] 2999** set at compile-time by a C preprocessor macro called 3000** [limits | SQLITE_MAX_<i>NAME</i>]. 3001** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3002** ^Attempts to increase a limit above its hard upper bound are 3003** silently truncated to the hard upper bound. 3004** 3005** ^Regardless of whether or not the limit was changed, the 3006** [sqlite3_limit()] interface returns the prior value of the limit. 3007** ^Hence, to find the current value of a limit without changing it, 3008** simply invoke this interface with the third parameter set to -1. 3009** 3010** Run-time limits are intended for use in applications that manage 3011** both their own internal database and also databases that are controlled 3012** by untrusted external sources. An example application might be a 3013** web browser that has its own databases for storing history and 3014** separate databases controlled by JavaScript applications downloaded 3015** off the Internet. The internal databases can be given the 3016** large, default limits. Databases managed by external sources can 3017** be given much smaller limits designed to prevent a denial of service 3018** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3019** interface to further control untrusted SQL. The size of the database 3020** created by an untrusted script can be contained using the 3021** [max_page_count] [PRAGMA]. 3022** 3023** New run-time limit categories may be added in future releases. 3024*/ 3025int sqlite3_limit(sqlite3*, int id, int newVal); 3026 3027/* 3028** CAPI3REF: Run-Time Limit Categories 3029** KEYWORDS: {limit category} {*limit categories} 3030** 3031** These constants define various performance limits 3032** that can be lowered at run-time using [sqlite3_limit()]. 3033** The synopsis of the meanings of the various limits is shown below. 3034** Additional information is available at [limits | Limits in SQLite]. 3035** 3036** <dl> 3037** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3038** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3039** 3040** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3041** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3042** 3043** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3044** <dd>The maximum number of columns in a table definition or in the 3045** result set of a [SELECT] or the maximum number of columns in an index 3046** or in an ORDER BY or GROUP BY clause.</dd>)^ 3047** 3048** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3049** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3050** 3051** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3052** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3053** 3054** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3055** <dd>The maximum number of instructions in a virtual machine program 3056** used to implement an SQL statement. This limit is not currently 3057** enforced, though that might be added in some future release of 3058** SQLite.</dd>)^ 3059** 3060** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3061** <dd>The maximum number of arguments on a function.</dd>)^ 3062** 3063** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3064** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3065** 3066** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3067** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3068** <dd>The maximum length of the pattern argument to the [LIKE] or 3069** [GLOB] operators.</dd>)^ 3070** 3071** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3072** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3073** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3074** 3075** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3076** <dd>The maximum depth of recursion for triggers.</dd>)^ 3077** 3078** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3079** <dd>The maximum number of auxiliary worker threads that a single 3080** [prepared statement] may start.</dd>)^ 3081** </dl> 3082*/ 3083#define SQLITE_LIMIT_LENGTH 0 3084#define SQLITE_LIMIT_SQL_LENGTH 1 3085#define SQLITE_LIMIT_COLUMN 2 3086#define SQLITE_LIMIT_EXPR_DEPTH 3 3087#define SQLITE_LIMIT_COMPOUND_SELECT 4 3088#define SQLITE_LIMIT_VDBE_OP 5 3089#define SQLITE_LIMIT_FUNCTION_ARG 6 3090#define SQLITE_LIMIT_ATTACHED 7 3091#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3092#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3093#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3094#define SQLITE_LIMIT_WORKER_THREADS 11 3095 3096/* 3097** CAPI3REF: Compiling An SQL Statement 3098** KEYWORDS: {SQL statement compiler} 3099** 3100** To execute an SQL query, it must first be compiled into a byte-code 3101** program using one of these routines. 3102** 3103** The first argument, "db", is a [database connection] obtained from a 3104** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3105** [sqlite3_open16()]. The database connection must not have been closed. 3106** 3107** The second argument, "zSql", is the statement to be compiled, encoded 3108** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3109** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3110** use UTF-16. 3111** 3112** ^If the nByte argument is less than zero, then zSql is read up to the 3113** first zero terminator. ^If nByte is non-negative, then it is the maximum 3114** number of bytes read from zSql. ^When nByte is non-negative, the 3115** zSql string ends at either the first '\000' or '\u0000' character or 3116** the nByte-th byte, whichever comes first. If the caller knows 3117** that the supplied string is nul-terminated, then there is a small 3118** performance advantage to be gained by passing an nByte parameter that 3119** is equal to the number of bytes in the input string <i>including</i> 3120** the nul-terminator bytes as this saves SQLite from having to 3121** make a copy of the input string. 3122** 3123** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3124** past the end of the first SQL statement in zSql. These routines only 3125** compile the first statement in zSql, so *pzTail is left pointing to 3126** what remains uncompiled. 3127** 3128** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3129** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3130** to NULL. ^If the input text contains no SQL (if the input is an empty 3131** string or a comment) then *ppStmt is set to NULL. 3132** The calling procedure is responsible for deleting the compiled 3133** SQL statement using [sqlite3_finalize()] after it has finished with it. 3134** ppStmt may not be NULL. 3135** 3136** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3137** otherwise an [error code] is returned. 3138** 3139** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3140** recommended for all new programs. The two older interfaces are retained 3141** for backwards compatibility, but their use is discouraged. 3142** ^In the "v2" interfaces, the prepared statement 3143** that is returned (the [sqlite3_stmt] object) contains a copy of the 3144** original SQL text. This causes the [sqlite3_step()] interface to 3145** behave differently in three ways: 3146** 3147** <ol> 3148** <li> 3149** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3150** always used to do, [sqlite3_step()] will automatically recompile the SQL 3151** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3152** retries will occur before sqlite3_step() gives up and returns an error. 3153** </li> 3154** 3155** <li> 3156** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3157** [error codes] or [extended error codes]. ^The legacy behavior was that 3158** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3159** and the application would have to make a second call to [sqlite3_reset()] 3160** in order to find the underlying cause of the problem. With the "v2" prepare 3161** interfaces, the underlying reason for the error is returned immediately. 3162** </li> 3163** 3164** <li> 3165** ^If the specific value bound to [parameter | host parameter] in the 3166** WHERE clause might influence the choice of query plan for a statement, 3167** then the statement will be automatically recompiled, as if there had been 3168** a schema change, on the first [sqlite3_step()] call following any change 3169** to the [sqlite3_bind_text | bindings] of that [parameter]. 3170** ^The specific value of WHERE-clause [parameter] might influence the 3171** choice of query plan if the parameter is the left-hand side of a [LIKE] 3172** or [GLOB] operator or if the parameter is compared to an indexed column 3173** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3174** </li> 3175** </ol> 3176*/ 3177int sqlite3_prepare( 3178 sqlite3 *db, /* Database handle */ 3179 const char *zSql, /* SQL statement, UTF-8 encoded */ 3180 int nByte, /* Maximum length of zSql in bytes. */ 3181 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3182 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3183); 3184int sqlite3_prepare_v2( 3185 sqlite3 *db, /* Database handle */ 3186 const char *zSql, /* SQL statement, UTF-8 encoded */ 3187 int nByte, /* Maximum length of zSql in bytes. */ 3188 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3189 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3190); 3191int sqlite3_prepare16( 3192 sqlite3 *db, /* Database handle */ 3193 const void *zSql, /* SQL statement, UTF-16 encoded */ 3194 int nByte, /* Maximum length of zSql in bytes. */ 3195 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3196 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3197); 3198int sqlite3_prepare16_v2( 3199 sqlite3 *db, /* Database handle */ 3200 const void *zSql, /* SQL statement, UTF-16 encoded */ 3201 int nByte, /* Maximum length of zSql in bytes. */ 3202 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3203 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3204); 3205 3206/* 3207** CAPI3REF: Retrieving Statement SQL 3208** 3209** ^This interface can be used to retrieve a saved copy of the original 3210** SQL text used to create a [prepared statement] if that statement was 3211** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3212*/ 3213const char *sqlite3_sql(sqlite3_stmt *pStmt); 3214 3215/* 3216** CAPI3REF: Determine If An SQL Statement Writes The Database 3217** 3218** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3219** and only if the [prepared statement] X makes no direct changes to 3220** the content of the database file. 3221** 3222** Note that [application-defined SQL functions] or 3223** [virtual tables] might change the database indirectly as a side effect. 3224** ^(For example, if an application defines a function "eval()" that 3225** calls [sqlite3_exec()], then the following SQL statement would 3226** change the database file through side-effects: 3227** 3228** <blockquote><pre> 3229** SELECT eval('DELETE FROM t1') FROM t2; 3230** </pre></blockquote> 3231** 3232** But because the [SELECT] statement does not change the database file 3233** directly, sqlite3_stmt_readonly() would still return true.)^ 3234** 3235** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3236** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3237** since the statements themselves do not actually modify the database but 3238** rather they control the timing of when other statements modify the 3239** database. ^The [ATTACH] and [DETACH] statements also cause 3240** sqlite3_stmt_readonly() to return true since, while those statements 3241** change the configuration of a database connection, they do not make 3242** changes to the content of the database files on disk. 3243*/ 3244int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3245 3246/* 3247** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3248** 3249** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3250** [prepared statement] S has been stepped at least once using 3251** [sqlite3_step(S)] but has not run to completion and/or has not 3252** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3253** interface returns false if S is a NULL pointer. If S is not a 3254** NULL pointer and is not a pointer to a valid [prepared statement] 3255** object, then the behavior is undefined and probably undesirable. 3256** 3257** This interface can be used in combination [sqlite3_next_stmt()] 3258** to locate all prepared statements associated with a database 3259** connection that are in need of being reset. This can be used, 3260** for example, in diagnostic routines to search for prepared 3261** statements that are holding a transaction open. 3262*/ 3263int sqlite3_stmt_busy(sqlite3_stmt*); 3264 3265/* 3266** CAPI3REF: Dynamically Typed Value Object 3267** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3268** 3269** SQLite uses the sqlite3_value object to represent all values 3270** that can be stored in a database table. SQLite uses dynamic typing 3271** for the values it stores. ^Values stored in sqlite3_value objects 3272** can be integers, floating point values, strings, BLOBs, or NULL. 3273** 3274** An sqlite3_value object may be either "protected" or "unprotected". 3275** Some interfaces require a protected sqlite3_value. Other interfaces 3276** will accept either a protected or an unprotected sqlite3_value. 3277** Every interface that accepts sqlite3_value arguments specifies 3278** whether or not it requires a protected sqlite3_value. 3279** 3280** The terms "protected" and "unprotected" refer to whether or not 3281** a mutex is held. An internal mutex is held for a protected 3282** sqlite3_value object but no mutex is held for an unprotected 3283** sqlite3_value object. If SQLite is compiled to be single-threaded 3284** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3285** or if SQLite is run in one of reduced mutex modes 3286** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3287** then there is no distinction between protected and unprotected 3288** sqlite3_value objects and they can be used interchangeably. However, 3289** for maximum code portability it is recommended that applications 3290** still make the distinction between protected and unprotected 3291** sqlite3_value objects even when not strictly required. 3292** 3293** ^The sqlite3_value objects that are passed as parameters into the 3294** implementation of [application-defined SQL functions] are protected. 3295** ^The sqlite3_value object returned by 3296** [sqlite3_column_value()] is unprotected. 3297** Unprotected sqlite3_value objects may only be used with 3298** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3299** The [sqlite3_value_blob | sqlite3_value_type()] family of 3300** interfaces require protected sqlite3_value objects. 3301*/ 3302typedef struct Mem sqlite3_value; 3303 3304/* 3305** CAPI3REF: SQL Function Context Object 3306** 3307** The context in which an SQL function executes is stored in an 3308** sqlite3_context object. ^A pointer to an sqlite3_context object 3309** is always first parameter to [application-defined SQL functions]. 3310** The application-defined SQL function implementation will pass this 3311** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3312** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3313** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3314** and/or [sqlite3_set_auxdata()]. 3315*/ 3316typedef struct sqlite3_context sqlite3_context; 3317 3318/* 3319** CAPI3REF: Binding Values To Prepared Statements 3320** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3321** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3322** 3323** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3324** literals may be replaced by a [parameter] that matches one of following 3325** templates: 3326** 3327** <ul> 3328** <li> ? 3329** <li> ?NNN 3330** <li> :VVV 3331** <li> @VVV 3332** <li> $VVV 3333** </ul> 3334** 3335** In the templates above, NNN represents an integer literal, 3336** and VVV represents an alphanumeric identifier.)^ ^The values of these 3337** parameters (also called "host parameter names" or "SQL parameters") 3338** can be set using the sqlite3_bind_*() routines defined here. 3339** 3340** ^The first argument to the sqlite3_bind_*() routines is always 3341** a pointer to the [sqlite3_stmt] object returned from 3342** [sqlite3_prepare_v2()] or its variants. 3343** 3344** ^The second argument is the index of the SQL parameter to be set. 3345** ^The leftmost SQL parameter has an index of 1. ^When the same named 3346** SQL parameter is used more than once, second and subsequent 3347** occurrences have the same index as the first occurrence. 3348** ^The index for named parameters can be looked up using the 3349** [sqlite3_bind_parameter_index()] API if desired. ^The index 3350** for "?NNN" parameters is the value of NNN. 3351** ^The NNN value must be between 1 and the [sqlite3_limit()] 3352** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3353** 3354** ^The third argument is the value to bind to the parameter. 3355** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3356** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3357** is ignored and the end result is the same as sqlite3_bind_null(). 3358** 3359** ^(In those routines that have a fourth argument, its value is the 3360** number of bytes in the parameter. To be clear: the value is the 3361** number of <u>bytes</u> in the value, not the number of characters.)^ 3362** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3363** is negative, then the length of the string is 3364** the number of bytes up to the first zero terminator. 3365** If the fourth parameter to sqlite3_bind_blob() is negative, then 3366** the behavior is undefined. 3367** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3368** or sqlite3_bind_text16() then that parameter must be the byte offset 3369** where the NUL terminator would occur assuming the string were NUL 3370** terminated. If any NUL characters occur at byte offsets less than 3371** the value of the fourth parameter then the resulting string value will 3372** contain embedded NULs. The result of expressions involving strings 3373** with embedded NULs is undefined. 3374** 3375** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3376** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3377** string after SQLite has finished with it. ^The destructor is called 3378** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3379** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3380** ^If the fifth argument is 3381** the special value [SQLITE_STATIC], then SQLite assumes that the 3382** information is in static, unmanaged space and does not need to be freed. 3383** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3384** SQLite makes its own private copy of the data immediately, before 3385** the sqlite3_bind_*() routine returns. 3386** 3387** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3388** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3389** (just an integer to hold its size) while it is being processed. 3390** Zeroblobs are intended to serve as placeholders for BLOBs whose 3391** content is later written using 3392** [sqlite3_blob_open | incremental BLOB I/O] routines. 3393** ^A negative value for the zeroblob results in a zero-length BLOB. 3394** 3395** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3396** for the [prepared statement] or with a prepared statement for which 3397** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3398** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3399** routine is passed a [prepared statement] that has been finalized, the 3400** result is undefined and probably harmful. 3401** 3402** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3403** ^Unbound parameters are interpreted as NULL. 3404** 3405** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3406** [error code] if anything goes wrong. 3407** ^[SQLITE_RANGE] is returned if the parameter 3408** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3409** 3410** See also: [sqlite3_bind_parameter_count()], 3411** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3412*/ 3413int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3414int sqlite3_bind_double(sqlite3_stmt*, int, double); 3415int sqlite3_bind_int(sqlite3_stmt*, int, int); 3416int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3417int sqlite3_bind_null(sqlite3_stmt*, int); 3418int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3419int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3420int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3421int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3422 3423/* 3424** CAPI3REF: Number Of SQL Parameters 3425** 3426** ^This routine can be used to find the number of [SQL parameters] 3427** in a [prepared statement]. SQL parameters are tokens of the 3428** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3429** placeholders for values that are [sqlite3_bind_blob | bound] 3430** to the parameters at a later time. 3431** 3432** ^(This routine actually returns the index of the largest (rightmost) 3433** parameter. For all forms except ?NNN, this will correspond to the 3434** number of unique parameters. If parameters of the ?NNN form are used, 3435** there may be gaps in the list.)^ 3436** 3437** See also: [sqlite3_bind_blob|sqlite3_bind()], 3438** [sqlite3_bind_parameter_name()], and 3439** [sqlite3_bind_parameter_index()]. 3440*/ 3441int sqlite3_bind_parameter_count(sqlite3_stmt*); 3442 3443/* 3444** CAPI3REF: Name Of A Host Parameter 3445** 3446** ^The sqlite3_bind_parameter_name(P,N) interface returns 3447** the name of the N-th [SQL parameter] in the [prepared statement] P. 3448** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3449** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3450** respectively. 3451** In other words, the initial ":" or "$" or "@" or "?" 3452** is included as part of the name.)^ 3453** ^Parameters of the form "?" without a following integer have no name 3454** and are referred to as "nameless" or "anonymous parameters". 3455** 3456** ^The first host parameter has an index of 1, not 0. 3457** 3458** ^If the value N is out of range or if the N-th parameter is 3459** nameless, then NULL is returned. ^The returned string is 3460** always in UTF-8 encoding even if the named parameter was 3461** originally specified as UTF-16 in [sqlite3_prepare16()] or 3462** [sqlite3_prepare16_v2()]. 3463** 3464** See also: [sqlite3_bind_blob|sqlite3_bind()], 3465** [sqlite3_bind_parameter_count()], and 3466** [sqlite3_bind_parameter_index()]. 3467*/ 3468const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3469 3470/* 3471** CAPI3REF: Index Of A Parameter With A Given Name 3472** 3473** ^Return the index of an SQL parameter given its name. ^The 3474** index value returned is suitable for use as the second 3475** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3476** is returned if no matching parameter is found. ^The parameter 3477** name must be given in UTF-8 even if the original statement 3478** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3479** 3480** See also: [sqlite3_bind_blob|sqlite3_bind()], 3481** [sqlite3_bind_parameter_count()], and 3482** [sqlite3_bind_parameter_index()]. 3483*/ 3484int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3485 3486/* 3487** CAPI3REF: Reset All Bindings On A Prepared Statement 3488** 3489** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3490** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3491** ^Use this routine to reset all host parameters to NULL. 3492*/ 3493int sqlite3_clear_bindings(sqlite3_stmt*); 3494 3495/* 3496** CAPI3REF: Number Of Columns In A Result Set 3497** 3498** ^Return the number of columns in the result set returned by the 3499** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3500** statement that does not return data (for example an [UPDATE]). 3501** 3502** See also: [sqlite3_data_count()] 3503*/ 3504int sqlite3_column_count(sqlite3_stmt *pStmt); 3505 3506/* 3507** CAPI3REF: Column Names In A Result Set 3508** 3509** ^These routines return the name assigned to a particular column 3510** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3511** interface returns a pointer to a zero-terminated UTF-8 string 3512** and sqlite3_column_name16() returns a pointer to a zero-terminated 3513** UTF-16 string. ^The first parameter is the [prepared statement] 3514** that implements the [SELECT] statement. ^The second parameter is the 3515** column number. ^The leftmost column is number 0. 3516** 3517** ^The returned string pointer is valid until either the [prepared statement] 3518** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3519** reprepared by the first call to [sqlite3_step()] for a particular run 3520** or until the next call to 3521** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3522** 3523** ^If sqlite3_malloc() fails during the processing of either routine 3524** (for example during a conversion from UTF-8 to UTF-16) then a 3525** NULL pointer is returned. 3526** 3527** ^The name of a result column is the value of the "AS" clause for 3528** that column, if there is an AS clause. If there is no AS clause 3529** then the name of the column is unspecified and may change from 3530** one release of SQLite to the next. 3531*/ 3532const char *sqlite3_column_name(sqlite3_stmt*, int N); 3533const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3534 3535/* 3536** CAPI3REF: Source Of Data In A Query Result 3537** 3538** ^These routines provide a means to determine the database, table, and 3539** table column that is the origin of a particular result column in 3540** [SELECT] statement. 3541** ^The name of the database or table or column can be returned as 3542** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3543** the database name, the _table_ routines return the table name, and 3544** the origin_ routines return the column name. 3545** ^The returned string is valid until the [prepared statement] is destroyed 3546** using [sqlite3_finalize()] or until the statement is automatically 3547** reprepared by the first call to [sqlite3_step()] for a particular run 3548** or until the same information is requested 3549** again in a different encoding. 3550** 3551** ^The names returned are the original un-aliased names of the 3552** database, table, and column. 3553** 3554** ^The first argument to these interfaces is a [prepared statement]. 3555** ^These functions return information about the Nth result column returned by 3556** the statement, where N is the second function argument. 3557** ^The left-most column is column 0 for these routines. 3558** 3559** ^If the Nth column returned by the statement is an expression or 3560** subquery and is not a column value, then all of these functions return 3561** NULL. ^These routine might also return NULL if a memory allocation error 3562** occurs. ^Otherwise, they return the name of the attached database, table, 3563** or column that query result column was extracted from. 3564** 3565** ^As with all other SQLite APIs, those whose names end with "16" return 3566** UTF-16 encoded strings and the other functions return UTF-8. 3567** 3568** ^These APIs are only available if the library was compiled with the 3569** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3570** 3571** If two or more threads call one or more of these routines against the same 3572** prepared statement and column at the same time then the results are 3573** undefined. 3574** 3575** If two or more threads call one or more 3576** [sqlite3_column_database_name | column metadata interfaces] 3577** for the same [prepared statement] and result column 3578** at the same time then the results are undefined. 3579*/ 3580const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3581const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3582const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3583const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3584const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3585const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3586 3587/* 3588** CAPI3REF: Declared Datatype Of A Query Result 3589** 3590** ^(The first parameter is a [prepared statement]. 3591** If this statement is a [SELECT] statement and the Nth column of the 3592** returned result set of that [SELECT] is a table column (not an 3593** expression or subquery) then the declared type of the table 3594** column is returned.)^ ^If the Nth column of the result set is an 3595** expression or subquery, then a NULL pointer is returned. 3596** ^The returned string is always UTF-8 encoded. 3597** 3598** ^(For example, given the database schema: 3599** 3600** CREATE TABLE t1(c1 VARIANT); 3601** 3602** and the following statement to be compiled: 3603** 3604** SELECT c1 + 1, c1 FROM t1; 3605** 3606** this routine would return the string "VARIANT" for the second result 3607** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3608** 3609** ^SQLite uses dynamic run-time typing. ^So just because a column 3610** is declared to contain a particular type does not mean that the 3611** data stored in that column is of the declared type. SQLite is 3612** strongly typed, but the typing is dynamic not static. ^Type 3613** is associated with individual values, not with the containers 3614** used to hold those values. 3615*/ 3616const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3617const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3618 3619/* 3620** CAPI3REF: Evaluate An SQL Statement 3621** 3622** After a [prepared statement] has been prepared using either 3623** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3624** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3625** must be called one or more times to evaluate the statement. 3626** 3627** The details of the behavior of the sqlite3_step() interface depend 3628** on whether the statement was prepared using the newer "v2" interface 3629** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3630** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3631** new "v2" interface is recommended for new applications but the legacy 3632** interface will continue to be supported. 3633** 3634** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3635** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3636** ^With the "v2" interface, any of the other [result codes] or 3637** [extended result codes] might be returned as well. 3638** 3639** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3640** database locks it needs to do its job. ^If the statement is a [COMMIT] 3641** or occurs outside of an explicit transaction, then you can retry the 3642** statement. If the statement is not a [COMMIT] and occurs within an 3643** explicit transaction then you should rollback the transaction before 3644** continuing. 3645** 3646** ^[SQLITE_DONE] means that the statement has finished executing 3647** successfully. sqlite3_step() should not be called again on this virtual 3648** machine without first calling [sqlite3_reset()] to reset the virtual 3649** machine back to its initial state. 3650** 3651** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3652** is returned each time a new row of data is ready for processing by the 3653** caller. The values may be accessed using the [column access functions]. 3654** sqlite3_step() is called again to retrieve the next row of data. 3655** 3656** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3657** violation) has occurred. sqlite3_step() should not be called again on 3658** the VM. More information may be found by calling [sqlite3_errmsg()]. 3659** ^With the legacy interface, a more specific error code (for example, 3660** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3661** can be obtained by calling [sqlite3_reset()] on the 3662** [prepared statement]. ^In the "v2" interface, 3663** the more specific error code is returned directly by sqlite3_step(). 3664** 3665** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3666** Perhaps it was called on a [prepared statement] that has 3667** already been [sqlite3_finalize | finalized] or on one that had 3668** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3669** be the case that the same database connection is being used by two or 3670** more threads at the same moment in time. 3671** 3672** For all versions of SQLite up to and including 3.6.23.1, a call to 3673** [sqlite3_reset()] was required after sqlite3_step() returned anything 3674** other than [SQLITE_ROW] before any subsequent invocation of 3675** sqlite3_step(). Failure to reset the prepared statement using 3676** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3677** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3678** calling [sqlite3_reset()] automatically in this circumstance rather 3679** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3680** break because any application that ever receives an SQLITE_MISUSE error 3681** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3682** can be used to restore the legacy behavior. 3683** 3684** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3685** API always returns a generic error code, [SQLITE_ERROR], following any 3686** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3687** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3688** specific [error codes] that better describes the error. 3689** We admit that this is a goofy design. The problem has been fixed 3690** with the "v2" interface. If you prepare all of your SQL statements 3691** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3692** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3693** then the more specific [error codes] are returned directly 3694** by sqlite3_step(). The use of the "v2" interface is recommended. 3695*/ 3696int sqlite3_step(sqlite3_stmt*); 3697 3698/* 3699** CAPI3REF: Number of columns in a result set 3700** 3701** ^The sqlite3_data_count(P) interface returns the number of columns in the 3702** current row of the result set of [prepared statement] P. 3703** ^If prepared statement P does not have results ready to return 3704** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3705** interfaces) then sqlite3_data_count(P) returns 0. 3706** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3707** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3708** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3709** will return non-zero if previous call to [sqlite3_step](P) returned 3710** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3711** where it always returns zero since each step of that multi-step 3712** pragma returns 0 columns of data. 3713** 3714** See also: [sqlite3_column_count()] 3715*/ 3716int sqlite3_data_count(sqlite3_stmt *pStmt); 3717 3718/* 3719** CAPI3REF: Fundamental Datatypes 3720** KEYWORDS: SQLITE_TEXT 3721** 3722** ^(Every value in SQLite has one of five fundamental datatypes: 3723** 3724** <ul> 3725** <li> 64-bit signed integer 3726** <li> 64-bit IEEE floating point number 3727** <li> string 3728** <li> BLOB 3729** <li> NULL 3730** </ul>)^ 3731** 3732** These constants are codes for each of those types. 3733** 3734** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3735** for a completely different meaning. Software that links against both 3736** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3737** SQLITE_TEXT. 3738*/ 3739#define SQLITE_INTEGER 1 3740#define SQLITE_FLOAT 2 3741#define SQLITE_BLOB 4 3742#define SQLITE_NULL 5 3743#ifdef SQLITE_TEXT 3744# undef SQLITE_TEXT 3745#else 3746# define SQLITE_TEXT 3 3747#endif 3748#define SQLITE3_TEXT 3 3749 3750/* 3751** CAPI3REF: Result Values From A Query 3752** KEYWORDS: {column access functions} 3753** 3754** These routines form the "result set" interface. 3755** 3756** ^These routines return information about a single column of the current 3757** result row of a query. ^In every case the first argument is a pointer 3758** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3759** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3760** and the second argument is the index of the column for which information 3761** should be returned. ^The leftmost column of the result set has the index 0. 3762** ^The number of columns in the result can be determined using 3763** [sqlite3_column_count()]. 3764** 3765** If the SQL statement does not currently point to a valid row, or if the 3766** column index is out of range, the result is undefined. 3767** These routines may only be called when the most recent call to 3768** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3769** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3770** If any of these routines are called after [sqlite3_reset()] or 3771** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3772** something other than [SQLITE_ROW], the results are undefined. 3773** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3774** are called from a different thread while any of these routines 3775** are pending, then the results are undefined. 3776** 3777** ^The sqlite3_column_type() routine returns the 3778** [SQLITE_INTEGER | datatype code] for the initial data type 3779** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3780** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3781** returned by sqlite3_column_type() is only meaningful if no type 3782** conversions have occurred as described below. After a type conversion, 3783** the value returned by sqlite3_column_type() is undefined. Future 3784** versions of SQLite may change the behavior of sqlite3_column_type() 3785** following a type conversion. 3786** 3787** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3788** routine returns the number of bytes in that BLOB or string. 3789** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3790** the string to UTF-8 and then returns the number of bytes. 3791** ^If the result is a numeric value then sqlite3_column_bytes() uses 3792** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3793** the number of bytes in that string. 3794** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3795** 3796** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3797** routine returns the number of bytes in that BLOB or string. 3798** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3799** the string to UTF-16 and then returns the number of bytes. 3800** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3801** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3802** the number of bytes in that string. 3803** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3804** 3805** ^The values returned by [sqlite3_column_bytes()] and 3806** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3807** of the string. ^For clarity: the values returned by 3808** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3809** bytes in the string, not the number of characters. 3810** 3811** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3812** even empty strings, are always zero-terminated. ^The return 3813** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3814** 3815** ^The object returned by [sqlite3_column_value()] is an 3816** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3817** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3818** If the [unprotected sqlite3_value] object returned by 3819** [sqlite3_column_value()] is used in any other way, including calls 3820** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3821** or [sqlite3_value_bytes()], then the behavior is undefined. 3822** 3823** These routines attempt to convert the value where appropriate. ^For 3824** example, if the internal representation is FLOAT and a text result 3825** is requested, [sqlite3_snprintf()] is used internally to perform the 3826** conversion automatically. ^(The following table details the conversions 3827** that are applied: 3828** 3829** <blockquote> 3830** <table border="1"> 3831** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3832** 3833** <tr><td> NULL <td> INTEGER <td> Result is 0 3834** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3835** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3836** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3837** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3838** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3839** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3840** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3841** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3842** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3843** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3844** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3845** <tr><td> TEXT <td> BLOB <td> No change 3846** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3847** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3848** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3849** </table> 3850** </blockquote>)^ 3851** 3852** The table above makes reference to standard C library functions atoi() 3853** and atof(). SQLite does not really use these functions. It has its 3854** own equivalent internal routines. The atoi() and atof() names are 3855** used in the table for brevity and because they are familiar to most 3856** C programmers. 3857** 3858** Note that when type conversions occur, pointers returned by prior 3859** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3860** sqlite3_column_text16() may be invalidated. 3861** Type conversions and pointer invalidations might occur 3862** in the following cases: 3863** 3864** <ul> 3865** <li> The initial content is a BLOB and sqlite3_column_text() or 3866** sqlite3_column_text16() is called. A zero-terminator might 3867** need to be added to the string.</li> 3868** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3869** sqlite3_column_text16() is called. The content must be converted 3870** to UTF-16.</li> 3871** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3872** sqlite3_column_text() is called. The content must be converted 3873** to UTF-8.</li> 3874** </ul> 3875** 3876** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3877** not invalidate a prior pointer, though of course the content of the buffer 3878** that the prior pointer references will have been modified. Other kinds 3879** of conversion are done in place when it is possible, but sometimes they 3880** are not possible and in those cases prior pointers are invalidated. 3881** 3882** The safest and easiest to remember policy is to invoke these routines 3883** in one of the following ways: 3884** 3885** <ul> 3886** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3887** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3888** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3889** </ul> 3890** 3891** In other words, you should call sqlite3_column_text(), 3892** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3893** into the desired format, then invoke sqlite3_column_bytes() or 3894** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3895** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3896** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3897** with calls to sqlite3_column_bytes(). 3898** 3899** ^The pointers returned are valid until a type conversion occurs as 3900** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3901** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3902** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3903** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3904** [sqlite3_free()]. 3905** 3906** ^(If a memory allocation error occurs during the evaluation of any 3907** of these routines, a default value is returned. The default value 3908** is either the integer 0, the floating point number 0.0, or a NULL 3909** pointer. Subsequent calls to [sqlite3_errcode()] will return 3910** [SQLITE_NOMEM].)^ 3911*/ 3912const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3913int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3914int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3915double sqlite3_column_double(sqlite3_stmt*, int iCol); 3916int sqlite3_column_int(sqlite3_stmt*, int iCol); 3917sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3918const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3919const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3920int sqlite3_column_type(sqlite3_stmt*, int iCol); 3921sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3922 3923/* 3924** CAPI3REF: Destroy A Prepared Statement Object 3925** 3926** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3927** ^If the most recent evaluation of the statement encountered no errors 3928** or if the statement is never been evaluated, then sqlite3_finalize() returns 3929** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3930** sqlite3_finalize(S) returns the appropriate [error code] or 3931** [extended error code]. 3932** 3933** ^The sqlite3_finalize(S) routine can be called at any point during 3934** the life cycle of [prepared statement] S: 3935** before statement S is ever evaluated, after 3936** one or more calls to [sqlite3_reset()], or after any call 3937** to [sqlite3_step()] regardless of whether or not the statement has 3938** completed execution. 3939** 3940** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3941** 3942** The application must finalize every [prepared statement] in order to avoid 3943** resource leaks. It is a grievous error for the application to try to use 3944** a prepared statement after it has been finalized. Any use of a prepared 3945** statement after it has been finalized can result in undefined and 3946** undesirable behavior such as segfaults and heap corruption. 3947*/ 3948int sqlite3_finalize(sqlite3_stmt *pStmt); 3949 3950/* 3951** CAPI3REF: Reset A Prepared Statement Object 3952** 3953** The sqlite3_reset() function is called to reset a [prepared statement] 3954** object back to its initial state, ready to be re-executed. 3955** ^Any SQL statement variables that had values bound to them using 3956** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3957** Use [sqlite3_clear_bindings()] to reset the bindings. 3958** 3959** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3960** back to the beginning of its program. 3961** 3962** ^If the most recent call to [sqlite3_step(S)] for the 3963** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3964** or if [sqlite3_step(S)] has never before been called on S, 3965** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3966** 3967** ^If the most recent call to [sqlite3_step(S)] for the 3968** [prepared statement] S indicated an error, then 3969** [sqlite3_reset(S)] returns an appropriate [error code]. 3970** 3971** ^The [sqlite3_reset(S)] interface does not change the values 3972** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3973*/ 3974int sqlite3_reset(sqlite3_stmt *pStmt); 3975 3976/* 3977** CAPI3REF: Create Or Redefine SQL Functions 3978** KEYWORDS: {function creation routines} 3979** KEYWORDS: {application-defined SQL function} 3980** KEYWORDS: {application-defined SQL functions} 3981** 3982** ^These functions (collectively known as "function creation routines") 3983** are used to add SQL functions or aggregates or to redefine the behavior 3984** of existing SQL functions or aggregates. The only differences between 3985** these routines are the text encoding expected for 3986** the second parameter (the name of the function being created) 3987** and the presence or absence of a destructor callback for 3988** the application data pointer. 3989** 3990** ^The first parameter is the [database connection] to which the SQL 3991** function is to be added. ^If an application uses more than one database 3992** connection then application-defined SQL functions must be added 3993** to each database connection separately. 3994** 3995** ^The second parameter is the name of the SQL function to be created or 3996** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3997** representation, exclusive of the zero-terminator. ^Note that the name 3998** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3999** ^Any attempt to create a function with a longer name 4000** will result in [SQLITE_MISUSE] being returned. 4001** 4002** ^The third parameter (nArg) 4003** is the number of arguments that the SQL function or 4004** aggregate takes. ^If this parameter is -1, then the SQL function or 4005** aggregate may take any number of arguments between 0 and the limit 4006** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4007** parameter is less than -1 or greater than 127 then the behavior is 4008** undefined. 4009** 4010** ^The fourth parameter, eTextRep, specifies what 4011** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4012** its parameters. The application should set this parameter to 4013** [SQLITE_UTF16LE] if the function implementation invokes 4014** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4015** implementation invokes [sqlite3_value_text16be()] on an input, or 4016** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4017** otherwise. ^The same SQL function may be registered multiple times using 4018** different preferred text encodings, with different implementations for 4019** each encoding. 4020** ^When multiple implementations of the same function are available, SQLite 4021** will pick the one that involves the least amount of data conversion. 4022** 4023** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4024** to signal that the function will always return the same result given 4025** the same inputs within a single SQL statement. Most SQL functions are 4026** deterministic. The built-in [random()] SQL function is an example of a 4027** function that is not deterministic. The SQLite query planner is able to 4028** perform additional optimizations on deterministic functions, so use 4029** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4030** 4031** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4032** function can gain access to this pointer using [sqlite3_user_data()].)^ 4033** 4034** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4035** pointers to C-language functions that implement the SQL function or 4036** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4037** callback only; NULL pointers must be passed as the xStep and xFinal 4038** parameters. ^An aggregate SQL function requires an implementation of xStep 4039** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4040** SQL function or aggregate, pass NULL pointers for all three function 4041** callbacks. 4042** 4043** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4044** then it is destructor for the application data pointer. 4045** The destructor is invoked when the function is deleted, either by being 4046** overloaded or when the database connection closes.)^ 4047** ^The destructor is also invoked if the call to 4048** sqlite3_create_function_v2() fails. 4049** ^When the destructor callback of the tenth parameter is invoked, it 4050** is passed a single argument which is a copy of the application data 4051** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4052** 4053** ^It is permitted to register multiple implementations of the same 4054** functions with the same name but with either differing numbers of 4055** arguments or differing preferred text encodings. ^SQLite will use 4056** the implementation that most closely matches the way in which the 4057** SQL function is used. ^A function implementation with a non-negative 4058** nArg parameter is a better match than a function implementation with 4059** a negative nArg. ^A function where the preferred text encoding 4060** matches the database encoding is a better 4061** match than a function where the encoding is different. 4062** ^A function where the encoding difference is between UTF16le and UTF16be 4063** is a closer match than a function where the encoding difference is 4064** between UTF8 and UTF16. 4065** 4066** ^Built-in functions may be overloaded by new application-defined functions. 4067** 4068** ^An application-defined function is permitted to call other 4069** SQLite interfaces. However, such calls must not 4070** close the database connection nor finalize or reset the prepared 4071** statement in which the function is running. 4072*/ 4073int sqlite3_create_function( 4074 sqlite3 *db, 4075 const char *zFunctionName, 4076 int nArg, 4077 int eTextRep, 4078 void *pApp, 4079 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4080 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4081 void (*xFinal)(sqlite3_context*) 4082); 4083int sqlite3_create_function16( 4084 sqlite3 *db, 4085 const void *zFunctionName, 4086 int nArg, 4087 int eTextRep, 4088 void *pApp, 4089 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4090 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4091 void (*xFinal)(sqlite3_context*) 4092); 4093int sqlite3_create_function_v2( 4094 sqlite3 *db, 4095 const char *zFunctionName, 4096 int nArg, 4097 int eTextRep, 4098 void *pApp, 4099 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4100 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4101 void (*xFinal)(sqlite3_context*), 4102 void(*xDestroy)(void*) 4103); 4104 4105/* 4106** CAPI3REF: Text Encodings 4107** 4108** These constant define integer codes that represent the various 4109** text encodings supported by SQLite. 4110*/ 4111#define SQLITE_UTF8 1 4112#define SQLITE_UTF16LE 2 4113#define SQLITE_UTF16BE 3 4114#define SQLITE_UTF16 4 /* Use native byte order */ 4115#define SQLITE_ANY 5 /* Deprecated */ 4116#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4117 4118/* 4119** CAPI3REF: Function Flags 4120** 4121** These constants may be ORed together with the 4122** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4123** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4124** [sqlite3_create_function_v2()]. 4125*/ 4126#define SQLITE_DETERMINISTIC 0x800 4127 4128/* 4129** CAPI3REF: Deprecated Functions 4130** DEPRECATED 4131** 4132** These functions are [deprecated]. In order to maintain 4133** backwards compatibility with older code, these functions continue 4134** to be supported. However, new applications should avoid 4135** the use of these functions. To help encourage people to avoid 4136** using these functions, we are not going to tell you what they do. 4137*/ 4138#ifndef SQLITE_OMIT_DEPRECATED 4139SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4140SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4141SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4142SQLITE_DEPRECATED int sqlite3_global_recover(void); 4143SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4144SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4145 void*,sqlite3_int64); 4146#endif 4147 4148/* 4149** CAPI3REF: Obtaining SQL Function Parameter Values 4150** 4151** The C-language implementation of SQL functions and aggregates uses 4152** this set of interface routines to access the parameter values on 4153** the function or aggregate. 4154** 4155** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4156** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4157** define callbacks that implement the SQL functions and aggregates. 4158** The 3rd parameter to these callbacks is an array of pointers to 4159** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4160** each parameter to the SQL function. These routines are used to 4161** extract values from the [sqlite3_value] objects. 4162** 4163** These routines work only with [protected sqlite3_value] objects. 4164** Any attempt to use these routines on an [unprotected sqlite3_value] 4165** object results in undefined behavior. 4166** 4167** ^These routines work just like the corresponding [column access functions] 4168** except that these routines take a single [protected sqlite3_value] object 4169** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4170** 4171** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4172** in the native byte-order of the host machine. ^The 4173** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4174** extract UTF-16 strings as big-endian and little-endian respectively. 4175** 4176** ^(The sqlite3_value_numeric_type() interface attempts to apply 4177** numeric affinity to the value. This means that an attempt is 4178** made to convert the value to an integer or floating point. If 4179** such a conversion is possible without loss of information (in other 4180** words, if the value is a string that looks like a number) 4181** then the conversion is performed. Otherwise no conversion occurs. 4182** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4183** 4184** Please pay particular attention to the fact that the pointer returned 4185** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4186** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4187** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4188** or [sqlite3_value_text16()]. 4189** 4190** These routines must be called from the same thread as 4191** the SQL function that supplied the [sqlite3_value*] parameters. 4192*/ 4193const void *sqlite3_value_blob(sqlite3_value*); 4194int sqlite3_value_bytes(sqlite3_value*); 4195int sqlite3_value_bytes16(sqlite3_value*); 4196double sqlite3_value_double(sqlite3_value*); 4197int sqlite3_value_int(sqlite3_value*); 4198sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4199const unsigned char *sqlite3_value_text(sqlite3_value*); 4200const void *sqlite3_value_text16(sqlite3_value*); 4201const void *sqlite3_value_text16le(sqlite3_value*); 4202const void *sqlite3_value_text16be(sqlite3_value*); 4203int sqlite3_value_type(sqlite3_value*); 4204int sqlite3_value_numeric_type(sqlite3_value*); 4205 4206/* 4207** CAPI3REF: Obtain Aggregate Function Context 4208** 4209** Implementations of aggregate SQL functions use this 4210** routine to allocate memory for storing their state. 4211** 4212** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4213** for a particular aggregate function, SQLite 4214** allocates N of memory, zeroes out that memory, and returns a pointer 4215** to the new memory. ^On second and subsequent calls to 4216** sqlite3_aggregate_context() for the same aggregate function instance, 4217** the same buffer is returned. Sqlite3_aggregate_context() is normally 4218** called once for each invocation of the xStep callback and then one 4219** last time when the xFinal callback is invoked. ^(When no rows match 4220** an aggregate query, the xStep() callback of the aggregate function 4221** implementation is never called and xFinal() is called exactly once. 4222** In those cases, sqlite3_aggregate_context() might be called for the 4223** first time from within xFinal().)^ 4224** 4225** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4226** when first called if N is less than or equal to zero or if a memory 4227** allocate error occurs. 4228** 4229** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4230** determined by the N parameter on first successful call. Changing the 4231** value of N in subsequent call to sqlite3_aggregate_context() within 4232** the same aggregate function instance will not resize the memory 4233** allocation.)^ Within the xFinal callback, it is customary to set 4234** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4235** pointless memory allocations occur. 4236** 4237** ^SQLite automatically frees the memory allocated by 4238** sqlite3_aggregate_context() when the aggregate query concludes. 4239** 4240** The first parameter must be a copy of the 4241** [sqlite3_context | SQL function context] that is the first parameter 4242** to the xStep or xFinal callback routine that implements the aggregate 4243** function. 4244** 4245** This routine must be called from the same thread in which 4246** the aggregate SQL function is running. 4247*/ 4248void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4249 4250/* 4251** CAPI3REF: User Data For Functions 4252** 4253** ^The sqlite3_user_data() interface returns a copy of 4254** the pointer that was the pUserData parameter (the 5th parameter) 4255** of the [sqlite3_create_function()] 4256** and [sqlite3_create_function16()] routines that originally 4257** registered the application defined function. 4258** 4259** This routine must be called from the same thread in which 4260** the application-defined function is running. 4261*/ 4262void *sqlite3_user_data(sqlite3_context*); 4263 4264/* 4265** CAPI3REF: Database Connection For Functions 4266** 4267** ^The sqlite3_context_db_handle() interface returns a copy of 4268** the pointer to the [database connection] (the 1st parameter) 4269** of the [sqlite3_create_function()] 4270** and [sqlite3_create_function16()] routines that originally 4271** registered the application defined function. 4272*/ 4273sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4274 4275/* 4276** CAPI3REF: Function Auxiliary Data 4277** 4278** These functions may be used by (non-aggregate) SQL functions to 4279** associate metadata with argument values. If the same value is passed to 4280** multiple invocations of the same SQL function during query execution, under 4281** some circumstances the associated metadata may be preserved. An example 4282** of where this might be useful is in a regular-expression matching 4283** function. The compiled version of the regular expression can be stored as 4284** metadata associated with the pattern string. 4285** Then as long as the pattern string remains the same, 4286** the compiled regular expression can be reused on multiple 4287** invocations of the same function. 4288** 4289** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4290** associated by the sqlite3_set_auxdata() function with the Nth argument 4291** value to the application-defined function. ^If there is no metadata 4292** associated with the function argument, this sqlite3_get_auxdata() interface 4293** returns a NULL pointer. 4294** 4295** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4296** argument of the application-defined function. ^Subsequent 4297** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4298** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4299** NULL if the metadata has been discarded. 4300** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4301** SQLite will invoke the destructor function X with parameter P exactly 4302** once, when the metadata is discarded. 4303** SQLite is free to discard the metadata at any time, including: <ul> 4304** <li> when the corresponding function parameter changes, or 4305** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4306** SQL statement, or 4307** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4308** <li> during the original sqlite3_set_auxdata() call when a memory 4309** allocation error occurs. </ul>)^ 4310** 4311** Note the last bullet in particular. The destructor X in 4312** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4313** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4314** should be called near the end of the function implementation and the 4315** function implementation should not make any use of P after 4316** sqlite3_set_auxdata() has been called. 4317** 4318** ^(In practice, metadata is preserved between function calls for 4319** function parameters that are compile-time constants, including literal 4320** values and [parameters] and expressions composed from the same.)^ 4321** 4322** These routines must be called from the same thread in which 4323** the SQL function is running. 4324*/ 4325void *sqlite3_get_auxdata(sqlite3_context*, int N); 4326void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4327 4328 4329/* 4330** CAPI3REF: Constants Defining Special Destructor Behavior 4331** 4332** These are special values for the destructor that is passed in as the 4333** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4334** argument is SQLITE_STATIC, it means that the content pointer is constant 4335** and will never change. It does not need to be destroyed. ^The 4336** SQLITE_TRANSIENT value means that the content will likely change in 4337** the near future and that SQLite should make its own private copy of 4338** the content before returning. 4339** 4340** The typedef is necessary to work around problems in certain 4341** C++ compilers. 4342*/ 4343typedef void (*sqlite3_destructor_type)(void*); 4344#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4345#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4346 4347/* 4348** CAPI3REF: Setting The Result Of An SQL Function 4349** 4350** These routines are used by the xFunc or xFinal callbacks that 4351** implement SQL functions and aggregates. See 4352** [sqlite3_create_function()] and [sqlite3_create_function16()] 4353** for additional information. 4354** 4355** These functions work very much like the [parameter binding] family of 4356** functions used to bind values to host parameters in prepared statements. 4357** Refer to the [SQL parameter] documentation for additional information. 4358** 4359** ^The sqlite3_result_blob() interface sets the result from 4360** an application-defined function to be the BLOB whose content is pointed 4361** to by the second parameter and which is N bytes long where N is the 4362** third parameter. 4363** 4364** ^The sqlite3_result_zeroblob() interfaces set the result of 4365** the application-defined function to be a BLOB containing all zero 4366** bytes and N bytes in size, where N is the value of the 2nd parameter. 4367** 4368** ^The sqlite3_result_double() interface sets the result from 4369** an application-defined function to be a floating point value specified 4370** by its 2nd argument. 4371** 4372** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4373** cause the implemented SQL function to throw an exception. 4374** ^SQLite uses the string pointed to by the 4375** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4376** as the text of an error message. ^SQLite interprets the error 4377** message string from sqlite3_result_error() as UTF-8. ^SQLite 4378** interprets the string from sqlite3_result_error16() as UTF-16 in native 4379** byte order. ^If the third parameter to sqlite3_result_error() 4380** or sqlite3_result_error16() is negative then SQLite takes as the error 4381** message all text up through the first zero character. 4382** ^If the third parameter to sqlite3_result_error() or 4383** sqlite3_result_error16() is non-negative then SQLite takes that many 4384** bytes (not characters) from the 2nd parameter as the error message. 4385** ^The sqlite3_result_error() and sqlite3_result_error16() 4386** routines make a private copy of the error message text before 4387** they return. Hence, the calling function can deallocate or 4388** modify the text after they return without harm. 4389** ^The sqlite3_result_error_code() function changes the error code 4390** returned by SQLite as a result of an error in a function. ^By default, 4391** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4392** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4393** 4394** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4395** error indicating that a string or BLOB is too long to represent. 4396** 4397** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4398** error indicating that a memory allocation failed. 4399** 4400** ^The sqlite3_result_int() interface sets the return value 4401** of the application-defined function to be the 32-bit signed integer 4402** value given in the 2nd argument. 4403** ^The sqlite3_result_int64() interface sets the return value 4404** of the application-defined function to be the 64-bit signed integer 4405** value given in the 2nd argument. 4406** 4407** ^The sqlite3_result_null() interface sets the return value 4408** of the application-defined function to be NULL. 4409** 4410** ^The sqlite3_result_text(), sqlite3_result_text16(), 4411** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4412** set the return value of the application-defined function to be 4413** a text string which is represented as UTF-8, UTF-16 native byte order, 4414** UTF-16 little endian, or UTF-16 big endian, respectively. 4415** ^SQLite takes the text result from the application from 4416** the 2nd parameter of the sqlite3_result_text* interfaces. 4417** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4418** is negative, then SQLite takes result text from the 2nd parameter 4419** through the first zero character. 4420** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4421** is non-negative, then as many bytes (not characters) of the text 4422** pointed to by the 2nd parameter are taken as the application-defined 4423** function result. If the 3rd parameter is non-negative, then it 4424** must be the byte offset into the string where the NUL terminator would 4425** appear if the string where NUL terminated. If any NUL characters occur 4426** in the string at a byte offset that is less than the value of the 3rd 4427** parameter, then the resulting string will contain embedded NULs and the 4428** result of expressions operating on strings with embedded NULs is undefined. 4429** ^If the 4th parameter to the sqlite3_result_text* interfaces 4430** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4431** function as the destructor on the text or BLOB result when it has 4432** finished using that result. 4433** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4434** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4435** assumes that the text or BLOB result is in constant space and does not 4436** copy the content of the parameter nor call a destructor on the content 4437** when it has finished using that result. 4438** ^If the 4th parameter to the sqlite3_result_text* interfaces 4439** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4440** then SQLite makes a copy of the result into space obtained from 4441** from [sqlite3_malloc()] before it returns. 4442** 4443** ^The sqlite3_result_value() interface sets the result of 4444** the application-defined function to be a copy the 4445** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4446** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4447** so that the [sqlite3_value] specified in the parameter may change or 4448** be deallocated after sqlite3_result_value() returns without harm. 4449** ^A [protected sqlite3_value] object may always be used where an 4450** [unprotected sqlite3_value] object is required, so either 4451** kind of [sqlite3_value] object can be used with this interface. 4452** 4453** If these routines are called from within the different thread 4454** than the one containing the application-defined function that received 4455** the [sqlite3_context] pointer, the results are undefined. 4456*/ 4457void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4458void sqlite3_result_double(sqlite3_context*, double); 4459void sqlite3_result_error(sqlite3_context*, const char*, int); 4460void sqlite3_result_error16(sqlite3_context*, const void*, int); 4461void sqlite3_result_error_toobig(sqlite3_context*); 4462void sqlite3_result_error_nomem(sqlite3_context*); 4463void sqlite3_result_error_code(sqlite3_context*, int); 4464void sqlite3_result_int(sqlite3_context*, int); 4465void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4466void sqlite3_result_null(sqlite3_context*); 4467void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4468void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4469void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4470void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4471void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4472void sqlite3_result_zeroblob(sqlite3_context*, int n); 4473 4474/* 4475** CAPI3REF: Define New Collating Sequences 4476** 4477** ^These functions add, remove, or modify a [collation] associated 4478** with the [database connection] specified as the first argument. 4479** 4480** ^The name of the collation is a UTF-8 string 4481** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4482** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4483** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4484** considered to be the same name. 4485** 4486** ^(The third argument (eTextRep) must be one of the constants: 4487** <ul> 4488** <li> [SQLITE_UTF8], 4489** <li> [SQLITE_UTF16LE], 4490** <li> [SQLITE_UTF16BE], 4491** <li> [SQLITE_UTF16], or 4492** <li> [SQLITE_UTF16_ALIGNED]. 4493** </ul>)^ 4494** ^The eTextRep argument determines the encoding of strings passed 4495** to the collating function callback, xCallback. 4496** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4497** force strings to be UTF16 with native byte order. 4498** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4499** on an even byte address. 4500** 4501** ^The fourth argument, pArg, is an application data pointer that is passed 4502** through as the first argument to the collating function callback. 4503** 4504** ^The fifth argument, xCallback, is a pointer to the collating function. 4505** ^Multiple collating functions can be registered using the same name but 4506** with different eTextRep parameters and SQLite will use whichever 4507** function requires the least amount of data transformation. 4508** ^If the xCallback argument is NULL then the collating function is 4509** deleted. ^When all collating functions having the same name are deleted, 4510** that collation is no longer usable. 4511** 4512** ^The collating function callback is invoked with a copy of the pArg 4513** application data pointer and with two strings in the encoding specified 4514** by the eTextRep argument. The collating function must return an 4515** integer that is negative, zero, or positive 4516** if the first string is less than, equal to, or greater than the second, 4517** respectively. A collating function must always return the same answer 4518** given the same inputs. If two or more collating functions are registered 4519** to the same collation name (using different eTextRep values) then all 4520** must give an equivalent answer when invoked with equivalent strings. 4521** The collating function must obey the following properties for all 4522** strings A, B, and C: 4523** 4524** <ol> 4525** <li> If A==B then B==A. 4526** <li> If A==B and B==C then A==C. 4527** <li> If A<B THEN B>A. 4528** <li> If A<B and B<C then A<C. 4529** </ol> 4530** 4531** If a collating function fails any of the above constraints and that 4532** collating function is registered and used, then the behavior of SQLite 4533** is undefined. 4534** 4535** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4536** with the addition that the xDestroy callback is invoked on pArg when 4537** the collating function is deleted. 4538** ^Collating functions are deleted when they are overridden by later 4539** calls to the collation creation functions or when the 4540** [database connection] is closed using [sqlite3_close()]. 4541** 4542** ^The xDestroy callback is <u>not</u> called if the 4543** sqlite3_create_collation_v2() function fails. Applications that invoke 4544** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4545** check the return code and dispose of the application data pointer 4546** themselves rather than expecting SQLite to deal with it for them. 4547** This is different from every other SQLite interface. The inconsistency 4548** is unfortunate but cannot be changed without breaking backwards 4549** compatibility. 4550** 4551** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4552*/ 4553int sqlite3_create_collation( 4554 sqlite3*, 4555 const char *zName, 4556 int eTextRep, 4557 void *pArg, 4558 int(*xCompare)(void*,int,const void*,int,const void*) 4559); 4560int sqlite3_create_collation_v2( 4561 sqlite3*, 4562 const char *zName, 4563 int eTextRep, 4564 void *pArg, 4565 int(*xCompare)(void*,int,const void*,int,const void*), 4566 void(*xDestroy)(void*) 4567); 4568int sqlite3_create_collation16( 4569 sqlite3*, 4570 const void *zName, 4571 int eTextRep, 4572 void *pArg, 4573 int(*xCompare)(void*,int,const void*,int,const void*) 4574); 4575 4576/* 4577** CAPI3REF: Collation Needed Callbacks 4578** 4579** ^To avoid having to register all collation sequences before a database 4580** can be used, a single callback function may be registered with the 4581** [database connection] to be invoked whenever an undefined collation 4582** sequence is required. 4583** 4584** ^If the function is registered using the sqlite3_collation_needed() API, 4585** then it is passed the names of undefined collation sequences as strings 4586** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4587** the names are passed as UTF-16 in machine native byte order. 4588** ^A call to either function replaces the existing collation-needed callback. 4589** 4590** ^(When the callback is invoked, the first argument passed is a copy 4591** of the second argument to sqlite3_collation_needed() or 4592** sqlite3_collation_needed16(). The second argument is the database 4593** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4594** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4595** sequence function required. The fourth parameter is the name of the 4596** required collation sequence.)^ 4597** 4598** The callback function should register the desired collation using 4599** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4600** [sqlite3_create_collation_v2()]. 4601*/ 4602int sqlite3_collation_needed( 4603 sqlite3*, 4604 void*, 4605 void(*)(void*,sqlite3*,int eTextRep,const char*) 4606); 4607int sqlite3_collation_needed16( 4608 sqlite3*, 4609 void*, 4610 void(*)(void*,sqlite3*,int eTextRep,const void*) 4611); 4612 4613#ifdef SQLITE_HAS_CODEC 4614/* 4615** Specify the key for an encrypted database. This routine should be 4616** called right after sqlite3_open(). 4617** 4618** The code to implement this API is not available in the public release 4619** of SQLite. 4620*/ 4621int sqlite3_key( 4622 sqlite3 *db, /* Database to be rekeyed */ 4623 const void *pKey, int nKey /* The key */ 4624); 4625int sqlite3_key_v2( 4626 sqlite3 *db, /* Database to be rekeyed */ 4627 const char *zDbName, /* Name of the database */ 4628 const void *pKey, int nKey /* The key */ 4629); 4630 4631/* 4632** Change the key on an open database. If the current database is not 4633** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4634** database is decrypted. 4635** 4636** The code to implement this API is not available in the public release 4637** of SQLite. 4638*/ 4639int sqlite3_rekey( 4640 sqlite3 *db, /* Database to be rekeyed */ 4641 const void *pKey, int nKey /* The new key */ 4642); 4643int sqlite3_rekey_v2( 4644 sqlite3 *db, /* Database to be rekeyed */ 4645 const char *zDbName, /* Name of the database */ 4646 const void *pKey, int nKey /* The new key */ 4647); 4648 4649/* 4650** Specify the activation key for a SEE database. Unless 4651** activated, none of the SEE routines will work. 4652*/ 4653void sqlite3_activate_see( 4654 const char *zPassPhrase /* Activation phrase */ 4655); 4656#endif 4657 4658#ifdef SQLITE_ENABLE_CEROD 4659/* 4660** Specify the activation key for a CEROD database. Unless 4661** activated, none of the CEROD routines will work. 4662*/ 4663void sqlite3_activate_cerod( 4664 const char *zPassPhrase /* Activation phrase */ 4665); 4666#endif 4667 4668/* 4669** CAPI3REF: Suspend Execution For A Short Time 4670** 4671** The sqlite3_sleep() function causes the current thread to suspend execution 4672** for at least a number of milliseconds specified in its parameter. 4673** 4674** If the operating system does not support sleep requests with 4675** millisecond time resolution, then the time will be rounded up to 4676** the nearest second. The number of milliseconds of sleep actually 4677** requested from the operating system is returned. 4678** 4679** ^SQLite implements this interface by calling the xSleep() 4680** method of the default [sqlite3_vfs] object. If the xSleep() method 4681** of the default VFS is not implemented correctly, or not implemented at 4682** all, then the behavior of sqlite3_sleep() may deviate from the description 4683** in the previous paragraphs. 4684*/ 4685int sqlite3_sleep(int); 4686 4687/* 4688** CAPI3REF: Name Of The Folder Holding Temporary Files 4689** 4690** ^(If this global variable is made to point to a string which is 4691** the name of a folder (a.k.a. directory), then all temporary files 4692** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4693** will be placed in that directory.)^ ^If this variable 4694** is a NULL pointer, then SQLite performs a search for an appropriate 4695** temporary file directory. 4696** 4697** Applications are strongly discouraged from using this global variable. 4698** It is required to set a temporary folder on Windows Runtime (WinRT). 4699** But for all other platforms, it is highly recommended that applications 4700** neither read nor write this variable. This global variable is a relic 4701** that exists for backwards compatibility of legacy applications and should 4702** be avoided in new projects. 4703** 4704** It is not safe to read or modify this variable in more than one 4705** thread at a time. It is not safe to read or modify this variable 4706** if a [database connection] is being used at the same time in a separate 4707** thread. 4708** It is intended that this variable be set once 4709** as part of process initialization and before any SQLite interface 4710** routines have been called and that this variable remain unchanged 4711** thereafter. 4712** 4713** ^The [temp_store_directory pragma] may modify this variable and cause 4714** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4715** the [temp_store_directory pragma] always assumes that any string 4716** that this variable points to is held in memory obtained from 4717** [sqlite3_malloc] and the pragma may attempt to free that memory 4718** using [sqlite3_free]. 4719** Hence, if this variable is modified directly, either it should be 4720** made NULL or made to point to memory obtained from [sqlite3_malloc] 4721** or else the use of the [temp_store_directory pragma] should be avoided. 4722** Except when requested by the [temp_store_directory pragma], SQLite 4723** does not free the memory that sqlite3_temp_directory points to. If 4724** the application wants that memory to be freed, it must do 4725** so itself, taking care to only do so after all [database connection] 4726** objects have been destroyed. 4727** 4728** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4729** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4730** features that require the use of temporary files may fail. Here is an 4731** example of how to do this using C++ with the Windows Runtime: 4732** 4733** <blockquote><pre> 4734** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4735** TemporaryFolder->Path->Data(); 4736** char zPathBuf[MAX_PATH + 1]; 4737** memset(zPathBuf, 0, sizeof(zPathBuf)); 4738** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4739** NULL, NULL); 4740** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4741** </pre></blockquote> 4742*/ 4743SQLITE_EXTERN char *sqlite3_temp_directory; 4744 4745/* 4746** CAPI3REF: Name Of The Folder Holding Database Files 4747** 4748** ^(If this global variable is made to point to a string which is 4749** the name of a folder (a.k.a. directory), then all database files 4750** specified with a relative pathname and created or accessed by 4751** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4752** to be relative to that directory.)^ ^If this variable is a NULL 4753** pointer, then SQLite assumes that all database files specified 4754** with a relative pathname are relative to the current directory 4755** for the process. Only the windows VFS makes use of this global 4756** variable; it is ignored by the unix VFS. 4757** 4758** Changing the value of this variable while a database connection is 4759** open can result in a corrupt database. 4760** 4761** It is not safe to read or modify this variable in more than one 4762** thread at a time. It is not safe to read or modify this variable 4763** if a [database connection] is being used at the same time in a separate 4764** thread. 4765** It is intended that this variable be set once 4766** as part of process initialization and before any SQLite interface 4767** routines have been called and that this variable remain unchanged 4768** thereafter. 4769** 4770** ^The [data_store_directory pragma] may modify this variable and cause 4771** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4772** the [data_store_directory pragma] always assumes that any string 4773** that this variable points to is held in memory obtained from 4774** [sqlite3_malloc] and the pragma may attempt to free that memory 4775** using [sqlite3_free]. 4776** Hence, if this variable is modified directly, either it should be 4777** made NULL or made to point to memory obtained from [sqlite3_malloc] 4778** or else the use of the [data_store_directory pragma] should be avoided. 4779*/ 4780SQLITE_EXTERN char *sqlite3_data_directory; 4781 4782/* 4783** CAPI3REF: Test For Auto-Commit Mode 4784** KEYWORDS: {autocommit mode} 4785** 4786** ^The sqlite3_get_autocommit() interface returns non-zero or 4787** zero if the given database connection is or is not in autocommit mode, 4788** respectively. ^Autocommit mode is on by default. 4789** ^Autocommit mode is disabled by a [BEGIN] statement. 4790** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4791** 4792** If certain kinds of errors occur on a statement within a multi-statement 4793** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4794** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4795** transaction might be rolled back automatically. The only way to 4796** find out whether SQLite automatically rolled back the transaction after 4797** an error is to use this function. 4798** 4799** If another thread changes the autocommit status of the database 4800** connection while this routine is running, then the return value 4801** is undefined. 4802*/ 4803int sqlite3_get_autocommit(sqlite3*); 4804 4805/* 4806** CAPI3REF: Find The Database Handle Of A Prepared Statement 4807** 4808** ^The sqlite3_db_handle interface returns the [database connection] handle 4809** to which a [prepared statement] belongs. ^The [database connection] 4810** returned by sqlite3_db_handle is the same [database connection] 4811** that was the first argument 4812** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4813** create the statement in the first place. 4814*/ 4815sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4816 4817/* 4818** CAPI3REF: Return The Filename For A Database Connection 4819** 4820** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4821** associated with database N of connection D. ^The main database file 4822** has the name "main". If there is no attached database N on the database 4823** connection D, or if database N is a temporary or in-memory database, then 4824** a NULL pointer is returned. 4825** 4826** ^The filename returned by this function is the output of the 4827** xFullPathname method of the [VFS]. ^In other words, the filename 4828** will be an absolute pathname, even if the filename used 4829** to open the database originally was a URI or relative pathname. 4830*/ 4831const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4832 4833/* 4834** CAPI3REF: Determine if a database is read-only 4835** 4836** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4837** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4838** the name of a database on connection D. 4839*/ 4840int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4841 4842/* 4843** CAPI3REF: Find the next prepared statement 4844** 4845** ^This interface returns a pointer to the next [prepared statement] after 4846** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4847** then this interface returns a pointer to the first prepared statement 4848** associated with the database connection pDb. ^If no prepared statement 4849** satisfies the conditions of this routine, it returns NULL. 4850** 4851** The [database connection] pointer D in a call to 4852** [sqlite3_next_stmt(D,S)] must refer to an open database 4853** connection and in particular must not be a NULL pointer. 4854*/ 4855sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4856 4857/* 4858** CAPI3REF: Commit And Rollback Notification Callbacks 4859** 4860** ^The sqlite3_commit_hook() interface registers a callback 4861** function to be invoked whenever a transaction is [COMMIT | committed]. 4862** ^Any callback set by a previous call to sqlite3_commit_hook() 4863** for the same database connection is overridden. 4864** ^The sqlite3_rollback_hook() interface registers a callback 4865** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4866** ^Any callback set by a previous call to sqlite3_rollback_hook() 4867** for the same database connection is overridden. 4868** ^The pArg argument is passed through to the callback. 4869** ^If the callback on a commit hook function returns non-zero, 4870** then the commit is converted into a rollback. 4871** 4872** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4873** return the P argument from the previous call of the same function 4874** on the same [database connection] D, or NULL for 4875** the first call for each function on D. 4876** 4877** The commit and rollback hook callbacks are not reentrant. 4878** The callback implementation must not do anything that will modify 4879** the database connection that invoked the callback. Any actions 4880** to modify the database connection must be deferred until after the 4881** completion of the [sqlite3_step()] call that triggered the commit 4882** or rollback hook in the first place. 4883** Note that running any other SQL statements, including SELECT statements, 4884** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4885** the database connections for the meaning of "modify" in this paragraph. 4886** 4887** ^Registering a NULL function disables the callback. 4888** 4889** ^When the commit hook callback routine returns zero, the [COMMIT] 4890** operation is allowed to continue normally. ^If the commit hook 4891** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4892** ^The rollback hook is invoked on a rollback that results from a commit 4893** hook returning non-zero, just as it would be with any other rollback. 4894** 4895** ^For the purposes of this API, a transaction is said to have been 4896** rolled back if an explicit "ROLLBACK" statement is executed, or 4897** an error or constraint causes an implicit rollback to occur. 4898** ^The rollback callback is not invoked if a transaction is 4899** automatically rolled back because the database connection is closed. 4900** 4901** See also the [sqlite3_update_hook()] interface. 4902*/ 4903void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4904void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4905 4906/* 4907** CAPI3REF: Data Change Notification Callbacks 4908** 4909** ^The sqlite3_update_hook() interface registers a callback function 4910** with the [database connection] identified by the first argument 4911** to be invoked whenever a row is updated, inserted or deleted in 4912** a rowid table. 4913** ^Any callback set by a previous call to this function 4914** for the same database connection is overridden. 4915** 4916** ^The second argument is a pointer to the function to invoke when a 4917** row is updated, inserted or deleted in a rowid table. 4918** ^The first argument to the callback is a copy of the third argument 4919** to sqlite3_update_hook(). 4920** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4921** or [SQLITE_UPDATE], depending on the operation that caused the callback 4922** to be invoked. 4923** ^The third and fourth arguments to the callback contain pointers to the 4924** database and table name containing the affected row. 4925** ^The final callback parameter is the [rowid] of the row. 4926** ^In the case of an update, this is the [rowid] after the update takes place. 4927** 4928** ^(The update hook is not invoked when internal system tables are 4929** modified (i.e. sqlite_master and sqlite_sequence).)^ 4930** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 4931** 4932** ^In the current implementation, the update hook 4933** is not invoked when duplication rows are deleted because of an 4934** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4935** invoked when rows are deleted using the [truncate optimization]. 4936** The exceptions defined in this paragraph might change in a future 4937** release of SQLite. 4938** 4939** The update hook implementation must not do anything that will modify 4940** the database connection that invoked the update hook. Any actions 4941** to modify the database connection must be deferred until after the 4942** completion of the [sqlite3_step()] call that triggered the update hook. 4943** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4944** database connections for the meaning of "modify" in this paragraph. 4945** 4946** ^The sqlite3_update_hook(D,C,P) function 4947** returns the P argument from the previous call 4948** on the same [database connection] D, or NULL for 4949** the first call on D. 4950** 4951** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4952** interfaces. 4953*/ 4954void *sqlite3_update_hook( 4955 sqlite3*, 4956 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4957 void* 4958); 4959 4960/* 4961** CAPI3REF: Enable Or Disable Shared Pager Cache 4962** 4963** ^(This routine enables or disables the sharing of the database cache 4964** and schema data structures between [database connection | connections] 4965** to the same database. Sharing is enabled if the argument is true 4966** and disabled if the argument is false.)^ 4967** 4968** ^Cache sharing is enabled and disabled for an entire process. 4969** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4970** sharing was enabled or disabled for each thread separately. 4971** 4972** ^(The cache sharing mode set by this interface effects all subsequent 4973** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4974** Existing database connections continue use the sharing mode 4975** that was in effect at the time they were opened.)^ 4976** 4977** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4978** successfully. An [error code] is returned otherwise.)^ 4979** 4980** ^Shared cache is disabled by default. But this might change in 4981** future releases of SQLite. Applications that care about shared 4982** cache setting should set it explicitly. 4983** 4984** This interface is threadsafe on processors where writing a 4985** 32-bit integer is atomic. 4986** 4987** See Also: [SQLite Shared-Cache Mode] 4988*/ 4989int sqlite3_enable_shared_cache(int); 4990 4991/* 4992** CAPI3REF: Attempt To Free Heap Memory 4993** 4994** ^The sqlite3_release_memory() interface attempts to free N bytes 4995** of heap memory by deallocating non-essential memory allocations 4996** held by the database library. Memory used to cache database 4997** pages to improve performance is an example of non-essential memory. 4998** ^sqlite3_release_memory() returns the number of bytes actually freed, 4999** which might be more or less than the amount requested. 5000** ^The sqlite3_release_memory() routine is a no-op returning zero 5001** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5002** 5003** See also: [sqlite3_db_release_memory()] 5004*/ 5005int sqlite3_release_memory(int); 5006 5007/* 5008** CAPI3REF: Free Memory Used By A Database Connection 5009** 5010** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5011** memory as possible from database connection D. Unlike the 5012** [sqlite3_release_memory()] interface, this interface is in effect even 5013** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5014** omitted. 5015** 5016** See also: [sqlite3_release_memory()] 5017*/ 5018int sqlite3_db_release_memory(sqlite3*); 5019 5020/* 5021** CAPI3REF: Impose A Limit On Heap Size 5022** 5023** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5024** soft limit on the amount of heap memory that may be allocated by SQLite. 5025** ^SQLite strives to keep heap memory utilization below the soft heap 5026** limit by reducing the number of pages held in the page cache 5027** as heap memory usages approaches the limit. 5028** ^The soft heap limit is "soft" because even though SQLite strives to stay 5029** below the limit, it will exceed the limit rather than generate 5030** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5031** is advisory only. 5032** 5033** ^The return value from sqlite3_soft_heap_limit64() is the size of 5034** the soft heap limit prior to the call, or negative in the case of an 5035** error. ^If the argument N is negative 5036** then no change is made to the soft heap limit. Hence, the current 5037** size of the soft heap limit can be determined by invoking 5038** sqlite3_soft_heap_limit64() with a negative argument. 5039** 5040** ^If the argument N is zero then the soft heap limit is disabled. 5041** 5042** ^(The soft heap limit is not enforced in the current implementation 5043** if one or more of following conditions are true: 5044** 5045** <ul> 5046** <li> The soft heap limit is set to zero. 5047** <li> Memory accounting is disabled using a combination of the 5048** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5049** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5050** <li> An alternative page cache implementation is specified using 5051** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5052** <li> The page cache allocates from its own memory pool supplied 5053** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5054** from the heap. 5055** </ul>)^ 5056** 5057** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5058** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5059** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5060** the soft heap limit is enforced on every memory allocation. Without 5061** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5062** when memory is allocated by the page cache. Testing suggests that because 5063** the page cache is the predominate memory user in SQLite, most 5064** applications will achieve adequate soft heap limit enforcement without 5065** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5066** 5067** The circumstances under which SQLite will enforce the soft heap limit may 5068** changes in future releases of SQLite. 5069*/ 5070sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5071 5072/* 5073** CAPI3REF: Deprecated Soft Heap Limit Interface 5074** DEPRECATED 5075** 5076** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5077** interface. This routine is provided for historical compatibility 5078** only. All new applications should use the 5079** [sqlite3_soft_heap_limit64()] interface rather than this one. 5080*/ 5081SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5082 5083 5084/* 5085** CAPI3REF: Extract Metadata About A Column Of A Table 5086** 5087** ^This routine returns metadata about a specific column of a specific 5088** database table accessible using the [database connection] handle 5089** passed as the first function argument. 5090** 5091** ^The column is identified by the second, third and fourth parameters to 5092** this function. ^The second parameter is either the name of the database 5093** (i.e. "main", "temp", or an attached database) containing the specified 5094** table or NULL. ^If it is NULL, then all attached databases are searched 5095** for the table using the same algorithm used by the database engine to 5096** resolve unqualified table references. 5097** 5098** ^The third and fourth parameters to this function are the table and column 5099** name of the desired column, respectively. Neither of these parameters 5100** may be NULL. 5101** 5102** ^Metadata is returned by writing to the memory locations passed as the 5th 5103** and subsequent parameters to this function. ^Any of these arguments may be 5104** NULL, in which case the corresponding element of metadata is omitted. 5105** 5106** ^(<blockquote> 5107** <table border="1"> 5108** <tr><th> Parameter <th> Output<br>Type <th> Description 5109** 5110** <tr><td> 5th <td> const char* <td> Data type 5111** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5112** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5113** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5114** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5115** </table> 5116** </blockquote>)^ 5117** 5118** ^The memory pointed to by the character pointers returned for the 5119** declaration type and collation sequence is valid only until the next 5120** call to any SQLite API function. 5121** 5122** ^If the specified table is actually a view, an [error code] is returned. 5123** 5124** ^If the specified column is "rowid", "oid" or "_rowid_" and an 5125** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5126** parameters are set for the explicitly declared column. ^(If there is no 5127** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5128** parameters are set as follows: 5129** 5130** <pre> 5131** data type: "INTEGER" 5132** collation sequence: "BINARY" 5133** not null: 0 5134** primary key: 1 5135** auto increment: 0 5136** </pre>)^ 5137** 5138** ^(This function may load one or more schemas from database files. If an 5139** error occurs during this process, or if the requested table or column 5140** cannot be found, an [error code] is returned and an error message left 5141** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5142** 5143** ^This API is only available if the library was compiled with the 5144** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5145*/ 5146int sqlite3_table_column_metadata( 5147 sqlite3 *db, /* Connection handle */ 5148 const char *zDbName, /* Database name or NULL */ 5149 const char *zTableName, /* Table name */ 5150 const char *zColumnName, /* Column name */ 5151 char const **pzDataType, /* OUTPUT: Declared data type */ 5152 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5153 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5154 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5155 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5156); 5157 5158/* 5159** CAPI3REF: Load An Extension 5160** 5161** ^This interface loads an SQLite extension library from the named file. 5162** 5163** ^The sqlite3_load_extension() interface attempts to load an 5164** [SQLite extension] library contained in the file zFile. If 5165** the file cannot be loaded directly, attempts are made to load 5166** with various operating-system specific extensions added. 5167** So for example, if "samplelib" cannot be loaded, then names like 5168** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5169** be tried also. 5170** 5171** ^The entry point is zProc. 5172** ^(zProc may be 0, in which case SQLite will try to come up with an 5173** entry point name on its own. It first tries "sqlite3_extension_init". 5174** If that does not work, it constructs a name "sqlite3_X_init" where the 5175** X is consists of the lower-case equivalent of all ASCII alphabetic 5176** characters in the filename from the last "/" to the first following 5177** "." and omitting any initial "lib".)^ 5178** ^The sqlite3_load_extension() interface returns 5179** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5180** ^If an error occurs and pzErrMsg is not 0, then the 5181** [sqlite3_load_extension()] interface shall attempt to 5182** fill *pzErrMsg with error message text stored in memory 5183** obtained from [sqlite3_malloc()]. The calling function 5184** should free this memory by calling [sqlite3_free()]. 5185** 5186** ^Extension loading must be enabled using 5187** [sqlite3_enable_load_extension()] prior to calling this API, 5188** otherwise an error will be returned. 5189** 5190** See also the [load_extension() SQL function]. 5191*/ 5192int sqlite3_load_extension( 5193 sqlite3 *db, /* Load the extension into this database connection */ 5194 const char *zFile, /* Name of the shared library containing extension */ 5195 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5196 char **pzErrMsg /* Put error message here if not 0 */ 5197); 5198 5199/* 5200** CAPI3REF: Enable Or Disable Extension Loading 5201** 5202** ^So as not to open security holes in older applications that are 5203** unprepared to deal with [extension loading], and as a means of disabling 5204** [extension loading] while evaluating user-entered SQL, the following API 5205** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5206** 5207** ^Extension loading is off by default. 5208** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5209** to turn extension loading on and call it with onoff==0 to turn 5210** it back off again. 5211*/ 5212int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5213 5214/* 5215** CAPI3REF: Automatically Load Statically Linked Extensions 5216** 5217** ^This interface causes the xEntryPoint() function to be invoked for 5218** each new [database connection] that is created. The idea here is that 5219** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5220** that is to be automatically loaded into all new database connections. 5221** 5222** ^(Even though the function prototype shows that xEntryPoint() takes 5223** no arguments and returns void, SQLite invokes xEntryPoint() with three 5224** arguments and expects and integer result as if the signature of the 5225** entry point where as follows: 5226** 5227** <blockquote><pre> 5228** int xEntryPoint( 5229** sqlite3 *db, 5230** const char **pzErrMsg, 5231** const struct sqlite3_api_routines *pThunk 5232** ); 5233** </pre></blockquote>)^ 5234** 5235** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5236** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5237** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5238** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5239** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5240** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5241** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5242** 5243** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5244** on the list of automatic extensions is a harmless no-op. ^No entry point 5245** will be called more than once for each database connection that is opened. 5246** 5247** See also: [sqlite3_reset_auto_extension()] 5248** and [sqlite3_cancel_auto_extension()] 5249*/ 5250int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5251 5252/* 5253** CAPI3REF: Cancel Automatic Extension Loading 5254** 5255** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5256** initialization routine X that was registered using a prior call to 5257** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5258** routine returns 1 if initialization routine X was successfully 5259** unregistered and it returns 0 if X was not on the list of initialization 5260** routines. 5261*/ 5262int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5263 5264/* 5265** CAPI3REF: Reset Automatic Extension Loading 5266** 5267** ^This interface disables all automatic extensions previously 5268** registered using [sqlite3_auto_extension()]. 5269*/ 5270void sqlite3_reset_auto_extension(void); 5271 5272/* 5273** The interface to the virtual-table mechanism is currently considered 5274** to be experimental. The interface might change in incompatible ways. 5275** If this is a problem for you, do not use the interface at this time. 5276** 5277** When the virtual-table mechanism stabilizes, we will declare the 5278** interface fixed, support it indefinitely, and remove this comment. 5279*/ 5280 5281/* 5282** Structures used by the virtual table interface 5283*/ 5284typedef struct sqlite3_vtab sqlite3_vtab; 5285typedef struct sqlite3_index_info sqlite3_index_info; 5286typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5287typedef struct sqlite3_module sqlite3_module; 5288 5289/* 5290** CAPI3REF: Virtual Table Object 5291** KEYWORDS: sqlite3_module {virtual table module} 5292** 5293** This structure, sometimes called a "virtual table module", 5294** defines the implementation of a [virtual tables]. 5295** This structure consists mostly of methods for the module. 5296** 5297** ^A virtual table module is created by filling in a persistent 5298** instance of this structure and passing a pointer to that instance 5299** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5300** ^The registration remains valid until it is replaced by a different 5301** module or until the [database connection] closes. The content 5302** of this structure must not change while it is registered with 5303** any database connection. 5304*/ 5305struct sqlite3_module { 5306 int iVersion; 5307 int (*xCreate)(sqlite3*, void *pAux, 5308 int argc, const char *const*argv, 5309 sqlite3_vtab **ppVTab, char**); 5310 int (*xConnect)(sqlite3*, void *pAux, 5311 int argc, const char *const*argv, 5312 sqlite3_vtab **ppVTab, char**); 5313 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5314 int (*xDisconnect)(sqlite3_vtab *pVTab); 5315 int (*xDestroy)(sqlite3_vtab *pVTab); 5316 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5317 int (*xClose)(sqlite3_vtab_cursor*); 5318 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5319 int argc, sqlite3_value **argv); 5320 int (*xNext)(sqlite3_vtab_cursor*); 5321 int (*xEof)(sqlite3_vtab_cursor*); 5322 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5323 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5324 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5325 int (*xBegin)(sqlite3_vtab *pVTab); 5326 int (*xSync)(sqlite3_vtab *pVTab); 5327 int (*xCommit)(sqlite3_vtab *pVTab); 5328 int (*xRollback)(sqlite3_vtab *pVTab); 5329 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5330 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5331 void **ppArg); 5332 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5333 /* The methods above are in version 1 of the sqlite_module object. Those 5334 ** below are for version 2 and greater. */ 5335 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5336 int (*xRelease)(sqlite3_vtab *pVTab, int); 5337 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5338}; 5339 5340/* 5341** CAPI3REF: Virtual Table Indexing Information 5342** KEYWORDS: sqlite3_index_info 5343** 5344** The sqlite3_index_info structure and its substructures is used as part 5345** of the [virtual table] interface to 5346** pass information into and receive the reply from the [xBestIndex] 5347** method of a [virtual table module]. The fields under **Inputs** are the 5348** inputs to xBestIndex and are read-only. xBestIndex inserts its 5349** results into the **Outputs** fields. 5350** 5351** ^(The aConstraint[] array records WHERE clause constraints of the form: 5352** 5353** <blockquote>column OP expr</blockquote> 5354** 5355** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5356** stored in aConstraint[].op using one of the 5357** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5358** ^(The index of the column is stored in 5359** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5360** expr on the right-hand side can be evaluated (and thus the constraint 5361** is usable) and false if it cannot.)^ 5362** 5363** ^The optimizer automatically inverts terms of the form "expr OP column" 5364** and makes other simplifications to the WHERE clause in an attempt to 5365** get as many WHERE clause terms into the form shown above as possible. 5366** ^The aConstraint[] array only reports WHERE clause terms that are 5367** relevant to the particular virtual table being queried. 5368** 5369** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5370** ^Each term of aOrderBy records a column of the ORDER BY clause. 5371** 5372** The [xBestIndex] method must fill aConstraintUsage[] with information 5373** about what parameters to pass to xFilter. ^If argvIndex>0 then 5374** the right-hand side of the corresponding aConstraint[] is evaluated 5375** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5376** is true, then the constraint is assumed to be fully handled by the 5377** virtual table and is not checked again by SQLite.)^ 5378** 5379** ^The idxNum and idxPtr values are recorded and passed into the 5380** [xFilter] method. 5381** ^[sqlite3_free()] is used to free idxPtr if and only if 5382** needToFreeIdxPtr is true. 5383** 5384** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5385** the correct order to satisfy the ORDER BY clause so that no separate 5386** sorting step is required. 5387** 5388** ^The estimatedCost value is an estimate of the cost of a particular 5389** strategy. A cost of N indicates that the cost of the strategy is similar 5390** to a linear scan of an SQLite table with N rows. A cost of log(N) 5391** indicates that the expense of the operation is similar to that of a 5392** binary search on a unique indexed field of an SQLite table with N rows. 5393** 5394** ^The estimatedRows value is an estimate of the number of rows that 5395** will be returned by the strategy. 5396** 5397** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5398** structure for SQLite version 3.8.2. If a virtual table extension is 5399** used with an SQLite version earlier than 3.8.2, the results of attempting 5400** to read or write the estimatedRows field are undefined (but are likely 5401** to included crashing the application). The estimatedRows field should 5402** therefore only be used if [sqlite3_libversion_number()] returns a 5403** value greater than or equal to 3008002. 5404*/ 5405struct sqlite3_index_info { 5406 /* Inputs */ 5407 int nConstraint; /* Number of entries in aConstraint */ 5408 struct sqlite3_index_constraint { 5409 int iColumn; /* Column on left-hand side of constraint */ 5410 unsigned char op; /* Constraint operator */ 5411 unsigned char usable; /* True if this constraint is usable */ 5412 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5413 } *aConstraint; /* Table of WHERE clause constraints */ 5414 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5415 struct sqlite3_index_orderby { 5416 int iColumn; /* Column number */ 5417 unsigned char desc; /* True for DESC. False for ASC. */ 5418 } *aOrderBy; /* The ORDER BY clause */ 5419 /* Outputs */ 5420 struct sqlite3_index_constraint_usage { 5421 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5422 unsigned char omit; /* Do not code a test for this constraint */ 5423 } *aConstraintUsage; 5424 int idxNum; /* Number used to identify the index */ 5425 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5426 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5427 int orderByConsumed; /* True if output is already ordered */ 5428 double estimatedCost; /* Estimated cost of using this index */ 5429 /* Fields below are only available in SQLite 3.8.2 and later */ 5430 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5431}; 5432 5433/* 5434** CAPI3REF: Virtual Table Constraint Operator Codes 5435** 5436** These macros defined the allowed values for the 5437** [sqlite3_index_info].aConstraint[].op field. Each value represents 5438** an operator that is part of a constraint term in the wHERE clause of 5439** a query that uses a [virtual table]. 5440*/ 5441#define SQLITE_INDEX_CONSTRAINT_EQ 2 5442#define SQLITE_INDEX_CONSTRAINT_GT 4 5443#define SQLITE_INDEX_CONSTRAINT_LE 8 5444#define SQLITE_INDEX_CONSTRAINT_LT 16 5445#define SQLITE_INDEX_CONSTRAINT_GE 32 5446#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5447 5448/* 5449** CAPI3REF: Register A Virtual Table Implementation 5450** 5451** ^These routines are used to register a new [virtual table module] name. 5452** ^Module names must be registered before 5453** creating a new [virtual table] using the module and before using a 5454** preexisting [virtual table] for the module. 5455** 5456** ^The module name is registered on the [database connection] specified 5457** by the first parameter. ^The name of the module is given by the 5458** second parameter. ^The third parameter is a pointer to 5459** the implementation of the [virtual table module]. ^The fourth 5460** parameter is an arbitrary client data pointer that is passed through 5461** into the [xCreate] and [xConnect] methods of the virtual table module 5462** when a new virtual table is be being created or reinitialized. 5463** 5464** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5465** is a pointer to a destructor for the pClientData. ^SQLite will 5466** invoke the destructor function (if it is not NULL) when SQLite 5467** no longer needs the pClientData pointer. ^The destructor will also 5468** be invoked if the call to sqlite3_create_module_v2() fails. 5469** ^The sqlite3_create_module() 5470** interface is equivalent to sqlite3_create_module_v2() with a NULL 5471** destructor. 5472*/ 5473int sqlite3_create_module( 5474 sqlite3 *db, /* SQLite connection to register module with */ 5475 const char *zName, /* Name of the module */ 5476 const sqlite3_module *p, /* Methods for the module */ 5477 void *pClientData /* Client data for xCreate/xConnect */ 5478); 5479int sqlite3_create_module_v2( 5480 sqlite3 *db, /* SQLite connection to register module with */ 5481 const char *zName, /* Name of the module */ 5482 const sqlite3_module *p, /* Methods for the module */ 5483 void *pClientData, /* Client data for xCreate/xConnect */ 5484 void(*xDestroy)(void*) /* Module destructor function */ 5485); 5486 5487/* 5488** CAPI3REF: Virtual Table Instance Object 5489** KEYWORDS: sqlite3_vtab 5490** 5491** Every [virtual table module] implementation uses a subclass 5492** of this object to describe a particular instance 5493** of the [virtual table]. Each subclass will 5494** be tailored to the specific needs of the module implementation. 5495** The purpose of this superclass is to define certain fields that are 5496** common to all module implementations. 5497** 5498** ^Virtual tables methods can set an error message by assigning a 5499** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5500** take care that any prior string is freed by a call to [sqlite3_free()] 5501** prior to assigning a new string to zErrMsg. ^After the error message 5502** is delivered up to the client application, the string will be automatically 5503** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5504*/ 5505struct sqlite3_vtab { 5506 const sqlite3_module *pModule; /* The module for this virtual table */ 5507 int nRef; /* NO LONGER USED */ 5508 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5509 /* Virtual table implementations will typically add additional fields */ 5510}; 5511 5512/* 5513** CAPI3REF: Virtual Table Cursor Object 5514** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5515** 5516** Every [virtual table module] implementation uses a subclass of the 5517** following structure to describe cursors that point into the 5518** [virtual table] and are used 5519** to loop through the virtual table. Cursors are created using the 5520** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5521** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5522** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5523** of the module. Each module implementation will define 5524** the content of a cursor structure to suit its own needs. 5525** 5526** This superclass exists in order to define fields of the cursor that 5527** are common to all implementations. 5528*/ 5529struct sqlite3_vtab_cursor { 5530 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5531 /* Virtual table implementations will typically add additional fields */ 5532}; 5533 5534/* 5535** CAPI3REF: Declare The Schema Of A Virtual Table 5536** 5537** ^The [xCreate] and [xConnect] methods of a 5538** [virtual table module] call this interface 5539** to declare the format (the names and datatypes of the columns) of 5540** the virtual tables they implement. 5541*/ 5542int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5543 5544/* 5545** CAPI3REF: Overload A Function For A Virtual Table 5546** 5547** ^(Virtual tables can provide alternative implementations of functions 5548** using the [xFindFunction] method of the [virtual table module]. 5549** But global versions of those functions 5550** must exist in order to be overloaded.)^ 5551** 5552** ^(This API makes sure a global version of a function with a particular 5553** name and number of parameters exists. If no such function exists 5554** before this API is called, a new function is created.)^ ^The implementation 5555** of the new function always causes an exception to be thrown. So 5556** the new function is not good for anything by itself. Its only 5557** purpose is to be a placeholder function that can be overloaded 5558** by a [virtual table]. 5559*/ 5560int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5561 5562/* 5563** The interface to the virtual-table mechanism defined above (back up 5564** to a comment remarkably similar to this one) is currently considered 5565** to be experimental. The interface might change in incompatible ways. 5566** If this is a problem for you, do not use the interface at this time. 5567** 5568** When the virtual-table mechanism stabilizes, we will declare the 5569** interface fixed, support it indefinitely, and remove this comment. 5570*/ 5571 5572/* 5573** CAPI3REF: A Handle To An Open BLOB 5574** KEYWORDS: {BLOB handle} {BLOB handles} 5575** 5576** An instance of this object represents an open BLOB on which 5577** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5578** ^Objects of this type are created by [sqlite3_blob_open()] 5579** and destroyed by [sqlite3_blob_close()]. 5580** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5581** can be used to read or write small subsections of the BLOB. 5582** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5583*/ 5584typedef struct sqlite3_blob sqlite3_blob; 5585 5586/* 5587** CAPI3REF: Open A BLOB For Incremental I/O 5588** 5589** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5590** in row iRow, column zColumn, table zTable in database zDb; 5591** in other words, the same BLOB that would be selected by: 5592** 5593** <pre> 5594** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5595** </pre>)^ 5596** 5597** ^If the flags parameter is non-zero, then the BLOB is opened for read 5598** and write access. ^If it is zero, the BLOB is opened for read access. 5599** ^It is not possible to open a column that is part of an index or primary 5600** key for writing. ^If [foreign key constraints] are enabled, it is 5601** not possible to open a column that is part of a [child key] for writing. 5602** 5603** ^Note that the database name is not the filename that contains 5604** the database but rather the symbolic name of the database that 5605** appears after the AS keyword when the database is connected using [ATTACH]. 5606** ^For the main database file, the database name is "main". 5607** ^For TEMP tables, the database name is "temp". 5608** 5609** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5610** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5611** to be a null pointer.)^ 5612** ^This function sets the [database connection] error code and message 5613** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5614** functions. ^Note that the *ppBlob variable is always initialized in a 5615** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5616** regardless of the success or failure of this routine. 5617** 5618** ^(If the row that a BLOB handle points to is modified by an 5619** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5620** then the BLOB handle is marked as "expired". 5621** This is true if any column of the row is changed, even a column 5622** other than the one the BLOB handle is open on.)^ 5623** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5624** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5625** ^(Changes written into a BLOB prior to the BLOB expiring are not 5626** rolled back by the expiration of the BLOB. Such changes will eventually 5627** commit if the transaction continues to completion.)^ 5628** 5629** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5630** the opened blob. ^The size of a blob may not be changed by this 5631** interface. Use the [UPDATE] SQL command to change the size of a 5632** blob. 5633** 5634** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] 5635** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. 5636** 5637** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5638** and the built-in [zeroblob] SQL function can be used, if desired, 5639** to create an empty, zero-filled blob in which to read or write using 5640** this interface. 5641** 5642** To avoid a resource leak, every open [BLOB handle] should eventually 5643** be released by a call to [sqlite3_blob_close()]. 5644*/ 5645int sqlite3_blob_open( 5646 sqlite3*, 5647 const char *zDb, 5648 const char *zTable, 5649 const char *zColumn, 5650 sqlite3_int64 iRow, 5651 int flags, 5652 sqlite3_blob **ppBlob 5653); 5654 5655/* 5656** CAPI3REF: Move a BLOB Handle to a New Row 5657** 5658** ^This function is used to move an existing blob handle so that it points 5659** to a different row of the same database table. ^The new row is identified 5660** by the rowid value passed as the second argument. Only the row can be 5661** changed. ^The database, table and column on which the blob handle is open 5662** remain the same. Moving an existing blob handle to a new row can be 5663** faster than closing the existing handle and opening a new one. 5664** 5665** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5666** it must exist and there must be either a blob or text value stored in 5667** the nominated column.)^ ^If the new row is not present in the table, or if 5668** it does not contain a blob or text value, or if another error occurs, an 5669** SQLite error code is returned and the blob handle is considered aborted. 5670** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5671** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5672** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5673** always returns zero. 5674** 5675** ^This function sets the database handle error code and message. 5676*/ 5677SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5678 5679/* 5680** CAPI3REF: Close A BLOB Handle 5681** 5682** ^Closes an open [BLOB handle]. 5683** 5684** ^Closing a BLOB shall cause the current transaction to commit 5685** if there are no other BLOBs, no pending prepared statements, and the 5686** database connection is in [autocommit mode]. 5687** ^If any writes were made to the BLOB, they might be held in cache 5688** until the close operation if they will fit. 5689** 5690** ^(Closing the BLOB often forces the changes 5691** out to disk and so if any I/O errors occur, they will likely occur 5692** at the time when the BLOB is closed. Any errors that occur during 5693** closing are reported as a non-zero return value.)^ 5694** 5695** ^(The BLOB is closed unconditionally. Even if this routine returns 5696** an error code, the BLOB is still closed.)^ 5697** 5698** ^Calling this routine with a null pointer (such as would be returned 5699** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5700*/ 5701int sqlite3_blob_close(sqlite3_blob *); 5702 5703/* 5704** CAPI3REF: Return The Size Of An Open BLOB 5705** 5706** ^Returns the size in bytes of the BLOB accessible via the 5707** successfully opened [BLOB handle] in its only argument. ^The 5708** incremental blob I/O routines can only read or overwriting existing 5709** blob content; they cannot change the size of a blob. 5710** 5711** This routine only works on a [BLOB handle] which has been created 5712** by a prior successful call to [sqlite3_blob_open()] and which has not 5713** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5714** to this routine results in undefined and probably undesirable behavior. 5715*/ 5716int sqlite3_blob_bytes(sqlite3_blob *); 5717 5718/* 5719** CAPI3REF: Read Data From A BLOB Incrementally 5720** 5721** ^(This function is used to read data from an open [BLOB handle] into a 5722** caller-supplied buffer. N bytes of data are copied into buffer Z 5723** from the open BLOB, starting at offset iOffset.)^ 5724** 5725** ^If offset iOffset is less than N bytes from the end of the BLOB, 5726** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5727** less than zero, [SQLITE_ERROR] is returned and no data is read. 5728** ^The size of the blob (and hence the maximum value of N+iOffset) 5729** can be determined using the [sqlite3_blob_bytes()] interface. 5730** 5731** ^An attempt to read from an expired [BLOB handle] fails with an 5732** error code of [SQLITE_ABORT]. 5733** 5734** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5735** Otherwise, an [error code] or an [extended error code] is returned.)^ 5736** 5737** This routine only works on a [BLOB handle] which has been created 5738** by a prior successful call to [sqlite3_blob_open()] and which has not 5739** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5740** to this routine results in undefined and probably undesirable behavior. 5741** 5742** See also: [sqlite3_blob_write()]. 5743*/ 5744int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5745 5746/* 5747** CAPI3REF: Write Data Into A BLOB Incrementally 5748** 5749** ^This function is used to write data into an open [BLOB handle] from a 5750** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5751** into the open BLOB, starting at offset iOffset. 5752** 5753** ^If the [BLOB handle] passed as the first argument was not opened for 5754** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5755** this function returns [SQLITE_READONLY]. 5756** 5757** ^This function may only modify the contents of the BLOB; it is 5758** not possible to increase the size of a BLOB using this API. 5759** ^If offset iOffset is less than N bytes from the end of the BLOB, 5760** [SQLITE_ERROR] is returned and no data is written. ^If N is 5761** less than zero [SQLITE_ERROR] is returned and no data is written. 5762** The size of the BLOB (and hence the maximum value of N+iOffset) 5763** can be determined using the [sqlite3_blob_bytes()] interface. 5764** 5765** ^An attempt to write to an expired [BLOB handle] fails with an 5766** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5767** before the [BLOB handle] expired are not rolled back by the 5768** expiration of the handle, though of course those changes might 5769** have been overwritten by the statement that expired the BLOB handle 5770** or by other independent statements. 5771** 5772** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5773** Otherwise, an [error code] or an [extended error code] is returned.)^ 5774** 5775** This routine only works on a [BLOB handle] which has been created 5776** by a prior successful call to [sqlite3_blob_open()] and which has not 5777** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5778** to this routine results in undefined and probably undesirable behavior. 5779** 5780** See also: [sqlite3_blob_read()]. 5781*/ 5782int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5783 5784/* 5785** CAPI3REF: Virtual File System Objects 5786** 5787** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5788** that SQLite uses to interact 5789** with the underlying operating system. Most SQLite builds come with a 5790** single default VFS that is appropriate for the host computer. 5791** New VFSes can be registered and existing VFSes can be unregistered. 5792** The following interfaces are provided. 5793** 5794** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5795** ^Names are case sensitive. 5796** ^Names are zero-terminated UTF-8 strings. 5797** ^If there is no match, a NULL pointer is returned. 5798** ^If zVfsName is NULL then the default VFS is returned. 5799** 5800** ^New VFSes are registered with sqlite3_vfs_register(). 5801** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5802** ^The same VFS can be registered multiple times without injury. 5803** ^To make an existing VFS into the default VFS, register it again 5804** with the makeDflt flag set. If two different VFSes with the 5805** same name are registered, the behavior is undefined. If a 5806** VFS is registered with a name that is NULL or an empty string, 5807** then the behavior is undefined. 5808** 5809** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5810** ^(If the default VFS is unregistered, another VFS is chosen as 5811** the default. The choice for the new VFS is arbitrary.)^ 5812*/ 5813sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5814int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5815int sqlite3_vfs_unregister(sqlite3_vfs*); 5816 5817/* 5818** CAPI3REF: Mutexes 5819** 5820** The SQLite core uses these routines for thread 5821** synchronization. Though they are intended for internal 5822** use by SQLite, code that links against SQLite is 5823** permitted to use any of these routines. 5824** 5825** The SQLite source code contains multiple implementations 5826** of these mutex routines. An appropriate implementation 5827** is selected automatically at compile-time. ^(The following 5828** implementations are available in the SQLite core: 5829** 5830** <ul> 5831** <li> SQLITE_MUTEX_PTHREADS 5832** <li> SQLITE_MUTEX_W32 5833** <li> SQLITE_MUTEX_NOOP 5834** </ul>)^ 5835** 5836** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5837** that does no real locking and is appropriate for use in 5838** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5839** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5840** and Windows. 5841** 5842** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5843** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5844** implementation is included with the library. In this case the 5845** application must supply a custom mutex implementation using the 5846** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5847** before calling sqlite3_initialize() or any other public sqlite3_ 5848** function that calls sqlite3_initialize().)^ 5849** 5850** ^The sqlite3_mutex_alloc() routine allocates a new 5851** mutex and returns a pointer to it. ^If it returns NULL 5852** that means that a mutex could not be allocated. ^SQLite 5853** will unwind its stack and return an error. ^(The argument 5854** to sqlite3_mutex_alloc() is one of these integer constants: 5855** 5856** <ul> 5857** <li> SQLITE_MUTEX_FAST 5858** <li> SQLITE_MUTEX_RECURSIVE 5859** <li> SQLITE_MUTEX_STATIC_MASTER 5860** <li> SQLITE_MUTEX_STATIC_MEM 5861** <li> SQLITE_MUTEX_STATIC_OPEN 5862** <li> SQLITE_MUTEX_STATIC_PRNG 5863** <li> SQLITE_MUTEX_STATIC_LRU 5864** <li> SQLITE_MUTEX_STATIC_PMEM 5865** <li> SQLITE_MUTEX_STATIC_APP1 5866** <li> SQLITE_MUTEX_STATIC_APP2 5867** </ul>)^ 5868** 5869** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5870** cause sqlite3_mutex_alloc() to create 5871** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5872** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5873** The mutex implementation does not need to make a distinction 5874** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5875** not want to. ^SQLite will only request a recursive mutex in 5876** cases where it really needs one. ^If a faster non-recursive mutex 5877** implementation is available on the host platform, the mutex subsystem 5878** might return such a mutex in response to SQLITE_MUTEX_FAST. 5879** 5880** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5881** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5882** a pointer to a static preexisting mutex. ^Six static mutexes are 5883** used by the current version of SQLite. Future versions of SQLite 5884** may add additional static mutexes. Static mutexes are for internal 5885** use by SQLite only. Applications that use SQLite mutexes should 5886** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5887** SQLITE_MUTEX_RECURSIVE. 5888** 5889** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5890** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5891** returns a different mutex on every call. ^But for the static 5892** mutex types, the same mutex is returned on every call that has 5893** the same type number. 5894** 5895** ^The sqlite3_mutex_free() routine deallocates a previously 5896** allocated dynamic mutex. ^SQLite is careful to deallocate every 5897** dynamic mutex that it allocates. The dynamic mutexes must not be in 5898** use when they are deallocated. Attempting to deallocate a static 5899** mutex results in undefined behavior. ^SQLite never deallocates 5900** a static mutex. 5901** 5902** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5903** to enter a mutex. ^If another thread is already within the mutex, 5904** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5905** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5906** upon successful entry. ^(Mutexes created using 5907** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5908** In such cases the, 5909** mutex must be exited an equal number of times before another thread 5910** can enter.)^ ^(If the same thread tries to enter any other 5911** kind of mutex more than once, the behavior is undefined. 5912** SQLite will never exhibit 5913** such behavior in its own use of mutexes.)^ 5914** 5915** ^(Some systems (for example, Windows 95) do not support the operation 5916** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5917** will always return SQLITE_BUSY. The SQLite core only ever uses 5918** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5919** 5920** ^The sqlite3_mutex_leave() routine exits a mutex that was 5921** previously entered by the same thread. ^(The behavior 5922** is undefined if the mutex is not currently entered by the 5923** calling thread or is not currently allocated. SQLite will 5924** never do either.)^ 5925** 5926** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5927** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5928** behave as no-ops. 5929** 5930** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5931*/ 5932sqlite3_mutex *sqlite3_mutex_alloc(int); 5933void sqlite3_mutex_free(sqlite3_mutex*); 5934void sqlite3_mutex_enter(sqlite3_mutex*); 5935int sqlite3_mutex_try(sqlite3_mutex*); 5936void sqlite3_mutex_leave(sqlite3_mutex*); 5937 5938/* 5939** CAPI3REF: Mutex Methods Object 5940** 5941** An instance of this structure defines the low-level routines 5942** used to allocate and use mutexes. 5943** 5944** Usually, the default mutex implementations provided by SQLite are 5945** sufficient, however the user has the option of substituting a custom 5946** implementation for specialized deployments or systems for which SQLite 5947** does not provide a suitable implementation. In this case, the user 5948** creates and populates an instance of this structure to pass 5949** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5950** Additionally, an instance of this structure can be used as an 5951** output variable when querying the system for the current mutex 5952** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5953** 5954** ^The xMutexInit method defined by this structure is invoked as 5955** part of system initialization by the sqlite3_initialize() function. 5956** ^The xMutexInit routine is called by SQLite exactly once for each 5957** effective call to [sqlite3_initialize()]. 5958** 5959** ^The xMutexEnd method defined by this structure is invoked as 5960** part of system shutdown by the sqlite3_shutdown() function. The 5961** implementation of this method is expected to release all outstanding 5962** resources obtained by the mutex methods implementation, especially 5963** those obtained by the xMutexInit method. ^The xMutexEnd() 5964** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5965** 5966** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5967** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5968** xMutexNotheld) implement the following interfaces (respectively): 5969** 5970** <ul> 5971** <li> [sqlite3_mutex_alloc()] </li> 5972** <li> [sqlite3_mutex_free()] </li> 5973** <li> [sqlite3_mutex_enter()] </li> 5974** <li> [sqlite3_mutex_try()] </li> 5975** <li> [sqlite3_mutex_leave()] </li> 5976** <li> [sqlite3_mutex_held()] </li> 5977** <li> [sqlite3_mutex_notheld()] </li> 5978** </ul>)^ 5979** 5980** The only difference is that the public sqlite3_XXX functions enumerated 5981** above silently ignore any invocations that pass a NULL pointer instead 5982** of a valid mutex handle. The implementations of the methods defined 5983** by this structure are not required to handle this case, the results 5984** of passing a NULL pointer instead of a valid mutex handle are undefined 5985** (i.e. it is acceptable to provide an implementation that segfaults if 5986** it is passed a NULL pointer). 5987** 5988** The xMutexInit() method must be threadsafe. ^It must be harmless to 5989** invoke xMutexInit() multiple times within the same process and without 5990** intervening calls to xMutexEnd(). Second and subsequent calls to 5991** xMutexInit() must be no-ops. 5992** 5993** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5994** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5995** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5996** memory allocation for a fast or recursive mutex. 5997** 5998** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5999** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6000** If xMutexInit fails in any way, it is expected to clean up after itself 6001** prior to returning. 6002*/ 6003typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6004struct sqlite3_mutex_methods { 6005 int (*xMutexInit)(void); 6006 int (*xMutexEnd)(void); 6007 sqlite3_mutex *(*xMutexAlloc)(int); 6008 void (*xMutexFree)(sqlite3_mutex *); 6009 void (*xMutexEnter)(sqlite3_mutex *); 6010 int (*xMutexTry)(sqlite3_mutex *); 6011 void (*xMutexLeave)(sqlite3_mutex *); 6012 int (*xMutexHeld)(sqlite3_mutex *); 6013 int (*xMutexNotheld)(sqlite3_mutex *); 6014}; 6015 6016/* 6017** CAPI3REF: Mutex Verification Routines 6018** 6019** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6020** are intended for use inside assert() statements. ^The SQLite core 6021** never uses these routines except inside an assert() and applications 6022** are advised to follow the lead of the core. ^The SQLite core only 6023** provides implementations for these routines when it is compiled 6024** with the SQLITE_DEBUG flag. ^External mutex implementations 6025** are only required to provide these routines if SQLITE_DEBUG is 6026** defined and if NDEBUG is not defined. 6027** 6028** ^These routines should return true if the mutex in their argument 6029** is held or not held, respectively, by the calling thread. 6030** 6031** ^The implementation is not required to provide versions of these 6032** routines that actually work. If the implementation does not provide working 6033** versions of these routines, it should at least provide stubs that always 6034** return true so that one does not get spurious assertion failures. 6035** 6036** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 6037** the routine should return 1. This seems counter-intuitive since 6038** clearly the mutex cannot be held if it does not exist. But 6039** the reason the mutex does not exist is because the build is not 6040** using mutexes. And we do not want the assert() containing the 6041** call to sqlite3_mutex_held() to fail, so a non-zero return is 6042** the appropriate thing to do. ^The sqlite3_mutex_notheld() 6043** interface should also return 1 when given a NULL pointer. 6044*/ 6045#ifndef NDEBUG 6046int sqlite3_mutex_held(sqlite3_mutex*); 6047int sqlite3_mutex_notheld(sqlite3_mutex*); 6048#endif 6049 6050/* 6051** CAPI3REF: Mutex Types 6052** 6053** The [sqlite3_mutex_alloc()] interface takes a single argument 6054** which is one of these integer constants. 6055** 6056** The set of static mutexes may change from one SQLite release to the 6057** next. Applications that override the built-in mutex logic must be 6058** prepared to accommodate additional static mutexes. 6059*/ 6060#define SQLITE_MUTEX_FAST 0 6061#define SQLITE_MUTEX_RECURSIVE 1 6062#define SQLITE_MUTEX_STATIC_MASTER 2 6063#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6064#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6065#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6066#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6067#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6068#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6069#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6070#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6071#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6072#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6073 6074/* 6075** CAPI3REF: Retrieve the mutex for a database connection 6076** 6077** ^This interface returns a pointer the [sqlite3_mutex] object that 6078** serializes access to the [database connection] given in the argument 6079** when the [threading mode] is Serialized. 6080** ^If the [threading mode] is Single-thread or Multi-thread then this 6081** routine returns a NULL pointer. 6082*/ 6083sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6084 6085/* 6086** CAPI3REF: Low-Level Control Of Database Files 6087** 6088** ^The [sqlite3_file_control()] interface makes a direct call to the 6089** xFileControl method for the [sqlite3_io_methods] object associated 6090** with a particular database identified by the second argument. ^The 6091** name of the database is "main" for the main database or "temp" for the 6092** TEMP database, or the name that appears after the AS keyword for 6093** databases that are added using the [ATTACH] SQL command. 6094** ^A NULL pointer can be used in place of "main" to refer to the 6095** main database file. 6096** ^The third and fourth parameters to this routine 6097** are passed directly through to the second and third parameters of 6098** the xFileControl method. ^The return value of the xFileControl 6099** method becomes the return value of this routine. 6100** 6101** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6102** a pointer to the underlying [sqlite3_file] object to be written into 6103** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6104** case is a short-circuit path which does not actually invoke the 6105** underlying sqlite3_io_methods.xFileControl method. 6106** 6107** ^If the second parameter (zDbName) does not match the name of any 6108** open database file, then SQLITE_ERROR is returned. ^This error 6109** code is not remembered and will not be recalled by [sqlite3_errcode()] 6110** or [sqlite3_errmsg()]. The underlying xFileControl method might 6111** also return SQLITE_ERROR. There is no way to distinguish between 6112** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6113** xFileControl method. 6114** 6115** See also: [SQLITE_FCNTL_LOCKSTATE] 6116*/ 6117int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6118 6119/* 6120** CAPI3REF: Testing Interface 6121** 6122** ^The sqlite3_test_control() interface is used to read out internal 6123** state of SQLite and to inject faults into SQLite for testing 6124** purposes. ^The first parameter is an operation code that determines 6125** the number, meaning, and operation of all subsequent parameters. 6126** 6127** This interface is not for use by applications. It exists solely 6128** for verifying the correct operation of the SQLite library. Depending 6129** on how the SQLite library is compiled, this interface might not exist. 6130** 6131** The details of the operation codes, their meanings, the parameters 6132** they take, and what they do are all subject to change without notice. 6133** Unlike most of the SQLite API, this function is not guaranteed to 6134** operate consistently from one release to the next. 6135*/ 6136int sqlite3_test_control(int op, ...); 6137 6138/* 6139** CAPI3REF: Testing Interface Operation Codes 6140** 6141** These constants are the valid operation code parameters used 6142** as the first argument to [sqlite3_test_control()]. 6143** 6144** These parameters and their meanings are subject to change 6145** without notice. These values are for testing purposes only. 6146** Applications should not use any of these parameters or the 6147** [sqlite3_test_control()] interface. 6148*/ 6149#define SQLITE_TESTCTRL_FIRST 5 6150#define SQLITE_TESTCTRL_PRNG_SAVE 5 6151#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6152#define SQLITE_TESTCTRL_PRNG_RESET 7 6153#define SQLITE_TESTCTRL_BITVEC_TEST 8 6154#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6155#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6156#define SQLITE_TESTCTRL_PENDING_BYTE 11 6157#define SQLITE_TESTCTRL_ASSERT 12 6158#define SQLITE_TESTCTRL_ALWAYS 13 6159#define SQLITE_TESTCTRL_RESERVE 14 6160#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6161#define SQLITE_TESTCTRL_ISKEYWORD 16 6162#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6163#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6164#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6165#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6166#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6167#define SQLITE_TESTCTRL_BYTEORDER 22 6168#define SQLITE_TESTCTRL_ISINIT 23 6169#define SQLITE_TESTCTRL_SORTER_MMAP 24 6170#define SQLITE_TESTCTRL_LAST 24 6171 6172/* 6173** CAPI3REF: SQLite Runtime Status 6174** 6175** ^This interface is used to retrieve runtime status information 6176** about the performance of SQLite, and optionally to reset various 6177** highwater marks. ^The first argument is an integer code for 6178** the specific parameter to measure. ^(Recognized integer codes 6179** are of the form [status parameters | SQLITE_STATUS_...].)^ 6180** ^The current value of the parameter is returned into *pCurrent. 6181** ^The highest recorded value is returned in *pHighwater. ^If the 6182** resetFlag is true, then the highest record value is reset after 6183** *pHighwater is written. ^(Some parameters do not record the highest 6184** value. For those parameters 6185** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6186** ^(Other parameters record only the highwater mark and not the current 6187** value. For these latter parameters nothing is written into *pCurrent.)^ 6188** 6189** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6190** non-zero [error code] on failure. 6191** 6192** This routine is threadsafe but is not atomic. This routine can be 6193** called while other threads are running the same or different SQLite 6194** interfaces. However the values returned in *pCurrent and 6195** *pHighwater reflect the status of SQLite at different points in time 6196** and it is possible that another thread might change the parameter 6197** in between the times when *pCurrent and *pHighwater are written. 6198** 6199** See also: [sqlite3_db_status()] 6200*/ 6201int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6202 6203 6204/* 6205** CAPI3REF: Status Parameters 6206** KEYWORDS: {status parameters} 6207** 6208** These integer constants designate various run-time status parameters 6209** that can be returned by [sqlite3_status()]. 6210** 6211** <dl> 6212** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6213** <dd>This parameter is the current amount of memory checked out 6214** using [sqlite3_malloc()], either directly or indirectly. The 6215** figure includes calls made to [sqlite3_malloc()] by the application 6216** and internal memory usage by the SQLite library. Scratch memory 6217** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6218** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6219** this parameter. The amount returned is the sum of the allocation 6220** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6221** 6222** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6223** <dd>This parameter records the largest memory allocation request 6224** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6225** internal equivalents). Only the value returned in the 6226** *pHighwater parameter to [sqlite3_status()] is of interest. 6227** The value written into the *pCurrent parameter is undefined.</dd>)^ 6228** 6229** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6230** <dd>This parameter records the number of separate memory allocations 6231** currently checked out.</dd>)^ 6232** 6233** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6234** <dd>This parameter returns the number of pages used out of the 6235** [pagecache memory allocator] that was configured using 6236** [SQLITE_CONFIG_PAGECACHE]. The 6237** value returned is in pages, not in bytes.</dd>)^ 6238** 6239** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6240** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6241** <dd>This parameter returns the number of bytes of page cache 6242** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6243** buffer and where forced to overflow to [sqlite3_malloc()]. The 6244** returned value includes allocations that overflowed because they 6245** where too large (they were larger than the "sz" parameter to 6246** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6247** no space was left in the page cache.</dd>)^ 6248** 6249** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6250** <dd>This parameter records the largest memory allocation request 6251** handed to [pagecache memory allocator]. Only the value returned in the 6252** *pHighwater parameter to [sqlite3_status()] is of interest. 6253** The value written into the *pCurrent parameter is undefined.</dd>)^ 6254** 6255** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6256** <dd>This parameter returns the number of allocations used out of the 6257** [scratch memory allocator] configured using 6258** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6259** in bytes. Since a single thread may only have one scratch allocation 6260** outstanding at time, this parameter also reports the number of threads 6261** using scratch memory at the same time.</dd>)^ 6262** 6263** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6264** <dd>This parameter returns the number of bytes of scratch memory 6265** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6266** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6267** returned include overflows because the requested allocation was too 6268** larger (that is, because the requested allocation was larger than the 6269** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6270** slots were available. 6271** </dd>)^ 6272** 6273** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6274** <dd>This parameter records the largest memory allocation request 6275** handed to [scratch memory allocator]. Only the value returned in the 6276** *pHighwater parameter to [sqlite3_status()] is of interest. 6277** The value written into the *pCurrent parameter is undefined.</dd>)^ 6278** 6279** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6280** <dd>This parameter records the deepest parser stack. It is only 6281** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6282** </dl> 6283** 6284** New status parameters may be added from time to time. 6285*/ 6286#define SQLITE_STATUS_MEMORY_USED 0 6287#define SQLITE_STATUS_PAGECACHE_USED 1 6288#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6289#define SQLITE_STATUS_SCRATCH_USED 3 6290#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6291#define SQLITE_STATUS_MALLOC_SIZE 5 6292#define SQLITE_STATUS_PARSER_STACK 6 6293#define SQLITE_STATUS_PAGECACHE_SIZE 7 6294#define SQLITE_STATUS_SCRATCH_SIZE 8 6295#define SQLITE_STATUS_MALLOC_COUNT 9 6296 6297/* 6298** CAPI3REF: Database Connection Status 6299** 6300** ^This interface is used to retrieve runtime status information 6301** about a single [database connection]. ^The first argument is the 6302** database connection object to be interrogated. ^The second argument 6303** is an integer constant, taken from the set of 6304** [SQLITE_DBSTATUS options], that 6305** determines the parameter to interrogate. The set of 6306** [SQLITE_DBSTATUS options] is likely 6307** to grow in future releases of SQLite. 6308** 6309** ^The current value of the requested parameter is written into *pCur 6310** and the highest instantaneous value is written into *pHiwtr. ^If 6311** the resetFlg is true, then the highest instantaneous value is 6312** reset back down to the current value. 6313** 6314** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6315** non-zero [error code] on failure. 6316** 6317** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6318*/ 6319int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6320 6321/* 6322** CAPI3REF: Status Parameters for database connections 6323** KEYWORDS: {SQLITE_DBSTATUS options} 6324** 6325** These constants are the available integer "verbs" that can be passed as 6326** the second argument to the [sqlite3_db_status()] interface. 6327** 6328** New verbs may be added in future releases of SQLite. Existing verbs 6329** might be discontinued. Applications should check the return code from 6330** [sqlite3_db_status()] to make sure that the call worked. 6331** The [sqlite3_db_status()] interface will return a non-zero error code 6332** if a discontinued or unsupported verb is invoked. 6333** 6334** <dl> 6335** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6336** <dd>This parameter returns the number of lookaside memory slots currently 6337** checked out.</dd>)^ 6338** 6339** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6340** <dd>This parameter returns the number malloc attempts that were 6341** satisfied using lookaside memory. Only the high-water value is meaningful; 6342** the current value is always zero.)^ 6343** 6344** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6345** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6346** <dd>This parameter returns the number malloc attempts that might have 6347** been satisfied using lookaside memory but failed due to the amount of 6348** memory requested being larger than the lookaside slot size. 6349** Only the high-water value is meaningful; 6350** the current value is always zero.)^ 6351** 6352** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6353** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6354** <dd>This parameter returns the number malloc attempts that might have 6355** been satisfied using lookaside memory but failed due to all lookaside 6356** memory already being in use. 6357** Only the high-water value is meaningful; 6358** the current value is always zero.)^ 6359** 6360** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6361** <dd>This parameter returns the approximate number of bytes of heap 6362** memory used by all pager caches associated with the database connection.)^ 6363** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6364** 6365** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6366** <dd>This parameter returns the approximate number of bytes of heap 6367** memory used to store the schema for all databases associated 6368** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6369** ^The full amount of memory used by the schemas is reported, even if the 6370** schema memory is shared with other database connections due to 6371** [shared cache mode] being enabled. 6372** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6373** 6374** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6375** <dd>This parameter returns the approximate number of bytes of heap 6376** and lookaside memory used by all prepared statements associated with 6377** the database connection.)^ 6378** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6379** </dd> 6380** 6381** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6382** <dd>This parameter returns the number of pager cache hits that have 6383** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6384** is always 0. 6385** </dd> 6386** 6387** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6388** <dd>This parameter returns the number of pager cache misses that have 6389** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6390** is always 0. 6391** </dd> 6392** 6393** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6394** <dd>This parameter returns the number of dirty cache entries that have 6395** been written to disk. Specifically, the number of pages written to the 6396** wal file in wal mode databases, or the number of pages written to the 6397** database file in rollback mode databases. Any pages written as part of 6398** transaction rollback or database recovery operations are not included. 6399** If an IO or other error occurs while writing a page to disk, the effect 6400** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6401** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6402** </dd> 6403** 6404** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6405** <dd>This parameter returns zero for the current value if and only if 6406** all foreign key constraints (deferred or immediate) have been 6407** resolved.)^ ^The highwater mark is always 0. 6408** </dd> 6409** </dl> 6410*/ 6411#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6412#define SQLITE_DBSTATUS_CACHE_USED 1 6413#define SQLITE_DBSTATUS_SCHEMA_USED 2 6414#define SQLITE_DBSTATUS_STMT_USED 3 6415#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6416#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6417#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6418#define SQLITE_DBSTATUS_CACHE_HIT 7 6419#define SQLITE_DBSTATUS_CACHE_MISS 8 6420#define SQLITE_DBSTATUS_CACHE_WRITE 9 6421#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6422#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6423 6424 6425/* 6426** CAPI3REF: Prepared Statement Status 6427** 6428** ^(Each prepared statement maintains various 6429** [SQLITE_STMTSTATUS counters] that measure the number 6430** of times it has performed specific operations.)^ These counters can 6431** be used to monitor the performance characteristics of the prepared 6432** statements. For example, if the number of table steps greatly exceeds 6433** the number of table searches or result rows, that would tend to indicate 6434** that the prepared statement is using a full table scan rather than 6435** an index. 6436** 6437** ^(This interface is used to retrieve and reset counter values from 6438** a [prepared statement]. The first argument is the prepared statement 6439** object to be interrogated. The second argument 6440** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6441** to be interrogated.)^ 6442** ^The current value of the requested counter is returned. 6443** ^If the resetFlg is true, then the counter is reset to zero after this 6444** interface call returns. 6445** 6446** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6447*/ 6448int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6449 6450/* 6451** CAPI3REF: Status Parameters for prepared statements 6452** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6453** 6454** These preprocessor macros define integer codes that name counter 6455** values associated with the [sqlite3_stmt_status()] interface. 6456** The meanings of the various counters are as follows: 6457** 6458** <dl> 6459** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6460** <dd>^This is the number of times that SQLite has stepped forward in 6461** a table as part of a full table scan. Large numbers for this counter 6462** may indicate opportunities for performance improvement through 6463** careful use of indices.</dd> 6464** 6465** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6466** <dd>^This is the number of sort operations that have occurred. 6467** A non-zero value in this counter may indicate an opportunity to 6468** improvement performance through careful use of indices.</dd> 6469** 6470** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6471** <dd>^This is the number of rows inserted into transient indices that 6472** were created automatically in order to help joins run faster. 6473** A non-zero value in this counter may indicate an opportunity to 6474** improvement performance by adding permanent indices that do not 6475** need to be reinitialized each time the statement is run.</dd> 6476** 6477** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6478** <dd>^This is the number of virtual machine operations executed 6479** by the prepared statement if that number is less than or equal 6480** to 2147483647. The number of virtual machine operations can be 6481** used as a proxy for the total work done by the prepared statement. 6482** If the number of virtual machine operations exceeds 2147483647 6483** then the value returned by this statement status code is undefined. 6484** </dd> 6485** </dl> 6486*/ 6487#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6488#define SQLITE_STMTSTATUS_SORT 2 6489#define SQLITE_STMTSTATUS_AUTOINDEX 3 6490#define SQLITE_STMTSTATUS_VM_STEP 4 6491 6492/* 6493** CAPI3REF: Custom Page Cache Object 6494** 6495** The sqlite3_pcache type is opaque. It is implemented by 6496** the pluggable module. The SQLite core has no knowledge of 6497** its size or internal structure and never deals with the 6498** sqlite3_pcache object except by holding and passing pointers 6499** to the object. 6500** 6501** See [sqlite3_pcache_methods2] for additional information. 6502*/ 6503typedef struct sqlite3_pcache sqlite3_pcache; 6504 6505/* 6506** CAPI3REF: Custom Page Cache Object 6507** 6508** The sqlite3_pcache_page object represents a single page in the 6509** page cache. The page cache will allocate instances of this 6510** object. Various methods of the page cache use pointers to instances 6511** of this object as parameters or as their return value. 6512** 6513** See [sqlite3_pcache_methods2] for additional information. 6514*/ 6515typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6516struct sqlite3_pcache_page { 6517 void *pBuf; /* The content of the page */ 6518 void *pExtra; /* Extra information associated with the page */ 6519}; 6520 6521/* 6522** CAPI3REF: Application Defined Page Cache. 6523** KEYWORDS: {page cache} 6524** 6525** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6526** register an alternative page cache implementation by passing in an 6527** instance of the sqlite3_pcache_methods2 structure.)^ 6528** In many applications, most of the heap memory allocated by 6529** SQLite is used for the page cache. 6530** By implementing a 6531** custom page cache using this API, an application can better control 6532** the amount of memory consumed by SQLite, the way in which 6533** that memory is allocated and released, and the policies used to 6534** determine exactly which parts of a database file are cached and for 6535** how long. 6536** 6537** The alternative page cache mechanism is an 6538** extreme measure that is only needed by the most demanding applications. 6539** The built-in page cache is recommended for most uses. 6540** 6541** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6542** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6543** the application may discard the parameter after the call to 6544** [sqlite3_config()] returns.)^ 6545** 6546** [[the xInit() page cache method]] 6547** ^(The xInit() method is called once for each effective 6548** call to [sqlite3_initialize()])^ 6549** (usually only once during the lifetime of the process). ^(The xInit() 6550** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6551** The intent of the xInit() method is to set up global data structures 6552** required by the custom page cache implementation. 6553** ^(If the xInit() method is NULL, then the 6554** built-in default page cache is used instead of the application defined 6555** page cache.)^ 6556** 6557** [[the xShutdown() page cache method]] 6558** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6559** It can be used to clean up 6560** any outstanding resources before process shutdown, if required. 6561** ^The xShutdown() method may be NULL. 6562** 6563** ^SQLite automatically serializes calls to the xInit method, 6564** so the xInit method need not be threadsafe. ^The 6565** xShutdown method is only called from [sqlite3_shutdown()] so it does 6566** not need to be threadsafe either. All other methods must be threadsafe 6567** in multithreaded applications. 6568** 6569** ^SQLite will never invoke xInit() more than once without an intervening 6570** call to xShutdown(). 6571** 6572** [[the xCreate() page cache methods]] 6573** ^SQLite invokes the xCreate() method to construct a new cache instance. 6574** SQLite will typically create one cache instance for each open database file, 6575** though this is not guaranteed. ^The 6576** first parameter, szPage, is the size in bytes of the pages that must 6577** be allocated by the cache. ^szPage will always a power of two. ^The 6578** second parameter szExtra is a number of bytes of extra storage 6579** associated with each page cache entry. ^The szExtra parameter will 6580** a number less than 250. SQLite will use the 6581** extra szExtra bytes on each page to store metadata about the underlying 6582** database page on disk. The value passed into szExtra depends 6583** on the SQLite version, the target platform, and how SQLite was compiled. 6584** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6585** created will be used to cache database pages of a file stored on disk, or 6586** false if it is used for an in-memory database. The cache implementation 6587** does not have to do anything special based with the value of bPurgeable; 6588** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6589** never invoke xUnpin() except to deliberately delete a page. 6590** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6591** false will always have the "discard" flag set to true. 6592** ^Hence, a cache created with bPurgeable false will 6593** never contain any unpinned pages. 6594** 6595** [[the xCachesize() page cache method]] 6596** ^(The xCachesize() method may be called at any time by SQLite to set the 6597** suggested maximum cache-size (number of pages stored by) the cache 6598** instance passed as the first argument. This is the value configured using 6599** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6600** parameter, the implementation is not required to do anything with this 6601** value; it is advisory only. 6602** 6603** [[the xPagecount() page cache methods]] 6604** The xPagecount() method must return the number of pages currently 6605** stored in the cache, both pinned and unpinned. 6606** 6607** [[the xFetch() page cache methods]] 6608** The xFetch() method locates a page in the cache and returns a pointer to 6609** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6610** The pBuf element of the returned sqlite3_pcache_page object will be a 6611** pointer to a buffer of szPage bytes used to store the content of a 6612** single database page. The pExtra element of sqlite3_pcache_page will be 6613** a pointer to the szExtra bytes of extra storage that SQLite has requested 6614** for each entry in the page cache. 6615** 6616** The page to be fetched is determined by the key. ^The minimum key value 6617** is 1. After it has been retrieved using xFetch, the page is considered 6618** to be "pinned". 6619** 6620** If the requested page is already in the page cache, then the page cache 6621** implementation must return a pointer to the page buffer with its content 6622** intact. If the requested page is not already in the cache, then the 6623** cache implementation should use the value of the createFlag 6624** parameter to help it determined what action to take: 6625** 6626** <table border=1 width=85% align=center> 6627** <tr><th> createFlag <th> Behavior when page is not already in cache 6628** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6629** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6630** Otherwise return NULL. 6631** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6632** NULL if allocating a new page is effectively impossible. 6633** </table> 6634** 6635** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6636** will only use a createFlag of 2 after a prior call with a createFlag of 1 6637** failed.)^ In between the to xFetch() calls, SQLite may 6638** attempt to unpin one or more cache pages by spilling the content of 6639** pinned pages to disk and synching the operating system disk cache. 6640** 6641** [[the xUnpin() page cache method]] 6642** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6643** as its second argument. If the third parameter, discard, is non-zero, 6644** then the page must be evicted from the cache. 6645** ^If the discard parameter is 6646** zero, then the page may be discarded or retained at the discretion of 6647** page cache implementation. ^The page cache implementation 6648** may choose to evict unpinned pages at any time. 6649** 6650** The cache must not perform any reference counting. A single 6651** call to xUnpin() unpins the page regardless of the number of prior calls 6652** to xFetch(). 6653** 6654** [[the xRekey() page cache methods]] 6655** The xRekey() method is used to change the key value associated with the 6656** page passed as the second argument. If the cache 6657** previously contains an entry associated with newKey, it must be 6658** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6659** to be pinned. 6660** 6661** When SQLite calls the xTruncate() method, the cache must discard all 6662** existing cache entries with page numbers (keys) greater than or equal 6663** to the value of the iLimit parameter passed to xTruncate(). If any 6664** of these pages are pinned, they are implicitly unpinned, meaning that 6665** they can be safely discarded. 6666** 6667** [[the xDestroy() page cache method]] 6668** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6669** All resources associated with the specified cache should be freed. ^After 6670** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6671** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6672** functions. 6673** 6674** [[the xShrink() page cache method]] 6675** ^SQLite invokes the xShrink() method when it wants the page cache to 6676** free up as much of heap memory as possible. The page cache implementation 6677** is not obligated to free any memory, but well-behaved implementations should 6678** do their best. 6679*/ 6680typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6681struct sqlite3_pcache_methods2 { 6682 int iVersion; 6683 void *pArg; 6684 int (*xInit)(void*); 6685 void (*xShutdown)(void*); 6686 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6687 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6688 int (*xPagecount)(sqlite3_pcache*); 6689 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6690 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6691 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6692 unsigned oldKey, unsigned newKey); 6693 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6694 void (*xDestroy)(sqlite3_pcache*); 6695 void (*xShrink)(sqlite3_pcache*); 6696}; 6697 6698/* 6699** This is the obsolete pcache_methods object that has now been replaced 6700** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6701** retained in the header file for backwards compatibility only. 6702*/ 6703typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6704struct sqlite3_pcache_methods { 6705 void *pArg; 6706 int (*xInit)(void*); 6707 void (*xShutdown)(void*); 6708 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6709 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6710 int (*xPagecount)(sqlite3_pcache*); 6711 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6712 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6713 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6714 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6715 void (*xDestroy)(sqlite3_pcache*); 6716}; 6717 6718 6719/* 6720** CAPI3REF: Online Backup Object 6721** 6722** The sqlite3_backup object records state information about an ongoing 6723** online backup operation. ^The sqlite3_backup object is created by 6724** a call to [sqlite3_backup_init()] and is destroyed by a call to 6725** [sqlite3_backup_finish()]. 6726** 6727** See Also: [Using the SQLite Online Backup API] 6728*/ 6729typedef struct sqlite3_backup sqlite3_backup; 6730 6731/* 6732** CAPI3REF: Online Backup API. 6733** 6734** The backup API copies the content of one database into another. 6735** It is useful either for creating backups of databases or 6736** for copying in-memory databases to or from persistent files. 6737** 6738** See Also: [Using the SQLite Online Backup API] 6739** 6740** ^SQLite holds a write transaction open on the destination database file 6741** for the duration of the backup operation. 6742** ^The source database is read-locked only while it is being read; 6743** it is not locked continuously for the entire backup operation. 6744** ^Thus, the backup may be performed on a live source database without 6745** preventing other database connections from 6746** reading or writing to the source database while the backup is underway. 6747** 6748** ^(To perform a backup operation: 6749** <ol> 6750** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6751** backup, 6752** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6753** the data between the two databases, and finally 6754** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6755** associated with the backup operation. 6756** </ol>)^ 6757** There should be exactly one call to sqlite3_backup_finish() for each 6758** successful call to sqlite3_backup_init(). 6759** 6760** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6761** 6762** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6763** [database connection] associated with the destination database 6764** and the database name, respectively. 6765** ^The database name is "main" for the main database, "temp" for the 6766** temporary database, or the name specified after the AS keyword in 6767** an [ATTACH] statement for an attached database. 6768** ^The S and M arguments passed to 6769** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6770** and database name of the source database, respectively. 6771** ^The source and destination [database connections] (parameters S and D) 6772** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6773** an error. 6774** 6775** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6776** returned and an error code and error message are stored in the 6777** destination [database connection] D. 6778** ^The error code and message for the failed call to sqlite3_backup_init() 6779** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6780** [sqlite3_errmsg16()] functions. 6781** ^A successful call to sqlite3_backup_init() returns a pointer to an 6782** [sqlite3_backup] object. 6783** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6784** sqlite3_backup_finish() functions to perform the specified backup 6785** operation. 6786** 6787** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6788** 6789** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6790** the source and destination databases specified by [sqlite3_backup] object B. 6791** ^If N is negative, all remaining source pages are copied. 6792** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6793** are still more pages to be copied, then the function returns [SQLITE_OK]. 6794** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6795** from source to destination, then it returns [SQLITE_DONE]. 6796** ^If an error occurs while running sqlite3_backup_step(B,N), 6797** then an [error code] is returned. ^As well as [SQLITE_OK] and 6798** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6799** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6800** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6801** 6802** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6803** <ol> 6804** <li> the destination database was opened read-only, or 6805** <li> the destination database is using write-ahead-log journaling 6806** and the destination and source page sizes differ, or 6807** <li> the destination database is an in-memory database and the 6808** destination and source page sizes differ. 6809** </ol>)^ 6810** 6811** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6812** the [sqlite3_busy_handler | busy-handler function] 6813** is invoked (if one is specified). ^If the 6814** busy-handler returns non-zero before the lock is available, then 6815** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6816** sqlite3_backup_step() can be retried later. ^If the source 6817** [database connection] 6818** is being used to write to the source database when sqlite3_backup_step() 6819** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6820** case the call to sqlite3_backup_step() can be retried later on. ^(If 6821** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6822** [SQLITE_READONLY] is returned, then 6823** there is no point in retrying the call to sqlite3_backup_step(). These 6824** errors are considered fatal.)^ The application must accept 6825** that the backup operation has failed and pass the backup operation handle 6826** to the sqlite3_backup_finish() to release associated resources. 6827** 6828** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6829** on the destination file. ^The exclusive lock is not released until either 6830** sqlite3_backup_finish() is called or the backup operation is complete 6831** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6832** sqlite3_backup_step() obtains a [shared lock] on the source database that 6833** lasts for the duration of the sqlite3_backup_step() call. 6834** ^Because the source database is not locked between calls to 6835** sqlite3_backup_step(), the source database may be modified mid-way 6836** through the backup process. ^If the source database is modified by an 6837** external process or via a database connection other than the one being 6838** used by the backup operation, then the backup will be automatically 6839** restarted by the next call to sqlite3_backup_step(). ^If the source 6840** database is modified by the using the same database connection as is used 6841** by the backup operation, then the backup database is automatically 6842** updated at the same time. 6843** 6844** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6845** 6846** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6847** application wishes to abandon the backup operation, the application 6848** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6849** ^The sqlite3_backup_finish() interfaces releases all 6850** resources associated with the [sqlite3_backup] object. 6851** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6852** active write-transaction on the destination database is rolled back. 6853** The [sqlite3_backup] object is invalid 6854** and may not be used following a call to sqlite3_backup_finish(). 6855** 6856** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6857** sqlite3_backup_step() errors occurred, regardless or whether or not 6858** sqlite3_backup_step() completed. 6859** ^If an out-of-memory condition or IO error occurred during any prior 6860** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6861** sqlite3_backup_finish() returns the corresponding [error code]. 6862** 6863** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6864** is not a permanent error and does not affect the return value of 6865** sqlite3_backup_finish(). 6866** 6867** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6868** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6869** 6870** ^Each call to sqlite3_backup_step() sets two values inside 6871** the [sqlite3_backup] object: the number of pages still to be backed 6872** up and the total number of pages in the source database file. 6873** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6874** retrieve these two values, respectively. 6875** 6876** ^The values returned by these functions are only updated by 6877** sqlite3_backup_step(). ^If the source database is modified during a backup 6878** operation, then the values are not updated to account for any extra 6879** pages that need to be updated or the size of the source database file 6880** changing. 6881** 6882** <b>Concurrent Usage of Database Handles</b> 6883** 6884** ^The source [database connection] may be used by the application for other 6885** purposes while a backup operation is underway or being initialized. 6886** ^If SQLite is compiled and configured to support threadsafe database 6887** connections, then the source database connection may be used concurrently 6888** from within other threads. 6889** 6890** However, the application must guarantee that the destination 6891** [database connection] is not passed to any other API (by any thread) after 6892** sqlite3_backup_init() is called and before the corresponding call to 6893** sqlite3_backup_finish(). SQLite does not currently check to see 6894** if the application incorrectly accesses the destination [database connection] 6895** and so no error code is reported, but the operations may malfunction 6896** nevertheless. Use of the destination database connection while a 6897** backup is in progress might also also cause a mutex deadlock. 6898** 6899** If running in [shared cache mode], the application must 6900** guarantee that the shared cache used by the destination database 6901** is not accessed while the backup is running. In practice this means 6902** that the application must guarantee that the disk file being 6903** backed up to is not accessed by any connection within the process, 6904** not just the specific connection that was passed to sqlite3_backup_init(). 6905** 6906** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6907** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6908** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6909** APIs are not strictly speaking threadsafe. If they are invoked at the 6910** same time as another thread is invoking sqlite3_backup_step() it is 6911** possible that they return invalid values. 6912*/ 6913sqlite3_backup *sqlite3_backup_init( 6914 sqlite3 *pDest, /* Destination database handle */ 6915 const char *zDestName, /* Destination database name */ 6916 sqlite3 *pSource, /* Source database handle */ 6917 const char *zSourceName /* Source database name */ 6918); 6919int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6920int sqlite3_backup_finish(sqlite3_backup *p); 6921int sqlite3_backup_remaining(sqlite3_backup *p); 6922int sqlite3_backup_pagecount(sqlite3_backup *p); 6923 6924/* 6925** CAPI3REF: Unlock Notification 6926** 6927** ^When running in shared-cache mode, a database operation may fail with 6928** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6929** individual tables within the shared-cache cannot be obtained. See 6930** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6931** ^This API may be used to register a callback that SQLite will invoke 6932** when the connection currently holding the required lock relinquishes it. 6933** ^This API is only available if the library was compiled with the 6934** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6935** 6936** See Also: [Using the SQLite Unlock Notification Feature]. 6937** 6938** ^Shared-cache locks are released when a database connection concludes 6939** its current transaction, either by committing it or rolling it back. 6940** 6941** ^When a connection (known as the blocked connection) fails to obtain a 6942** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6943** identity of the database connection (the blocking connection) that 6944** has locked the required resource is stored internally. ^After an 6945** application receives an SQLITE_LOCKED error, it may call the 6946** sqlite3_unlock_notify() method with the blocked connection handle as 6947** the first argument to register for a callback that will be invoked 6948** when the blocking connections current transaction is concluded. ^The 6949** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6950** call that concludes the blocking connections transaction. 6951** 6952** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6953** there is a chance that the blocking connection will have already 6954** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6955** If this happens, then the specified callback is invoked immediately, 6956** from within the call to sqlite3_unlock_notify().)^ 6957** 6958** ^If the blocked connection is attempting to obtain a write-lock on a 6959** shared-cache table, and more than one other connection currently holds 6960** a read-lock on the same table, then SQLite arbitrarily selects one of 6961** the other connections to use as the blocking connection. 6962** 6963** ^(There may be at most one unlock-notify callback registered by a 6964** blocked connection. If sqlite3_unlock_notify() is called when the 6965** blocked connection already has a registered unlock-notify callback, 6966** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6967** called with a NULL pointer as its second argument, then any existing 6968** unlock-notify callback is canceled. ^The blocked connections 6969** unlock-notify callback may also be canceled by closing the blocked 6970** connection using [sqlite3_close()]. 6971** 6972** The unlock-notify callback is not reentrant. If an application invokes 6973** any sqlite3_xxx API functions from within an unlock-notify callback, a 6974** crash or deadlock may be the result. 6975** 6976** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6977** returns SQLITE_OK. 6978** 6979** <b>Callback Invocation Details</b> 6980** 6981** When an unlock-notify callback is registered, the application provides a 6982** single void* pointer that is passed to the callback when it is invoked. 6983** However, the signature of the callback function allows SQLite to pass 6984** it an array of void* context pointers. The first argument passed to 6985** an unlock-notify callback is a pointer to an array of void* pointers, 6986** and the second is the number of entries in the array. 6987** 6988** When a blocking connections transaction is concluded, there may be 6989** more than one blocked connection that has registered for an unlock-notify 6990** callback. ^If two or more such blocked connections have specified the 6991** same callback function, then instead of invoking the callback function 6992** multiple times, it is invoked once with the set of void* context pointers 6993** specified by the blocked connections bundled together into an array. 6994** This gives the application an opportunity to prioritize any actions 6995** related to the set of unblocked database connections. 6996** 6997** <b>Deadlock Detection</b> 6998** 6999** Assuming that after registering for an unlock-notify callback a 7000** database waits for the callback to be issued before taking any further 7001** action (a reasonable assumption), then using this API may cause the 7002** application to deadlock. For example, if connection X is waiting for 7003** connection Y's transaction to be concluded, and similarly connection 7004** Y is waiting on connection X's transaction, then neither connection 7005** will proceed and the system may remain deadlocked indefinitely. 7006** 7007** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7008** detection. ^If a given call to sqlite3_unlock_notify() would put the 7009** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7010** unlock-notify callback is registered. The system is said to be in 7011** a deadlocked state if connection A has registered for an unlock-notify 7012** callback on the conclusion of connection B's transaction, and connection 7013** B has itself registered for an unlock-notify callback when connection 7014** A's transaction is concluded. ^Indirect deadlock is also detected, so 7015** the system is also considered to be deadlocked if connection B has 7016** registered for an unlock-notify callback on the conclusion of connection 7017** C's transaction, where connection C is waiting on connection A. ^Any 7018** number of levels of indirection are allowed. 7019** 7020** <b>The "DROP TABLE" Exception</b> 7021** 7022** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7023** always appropriate to call sqlite3_unlock_notify(). There is however, 7024** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7025** SQLite checks if there are any currently executing SELECT statements 7026** that belong to the same connection. If there are, SQLITE_LOCKED is 7027** returned. In this case there is no "blocking connection", so invoking 7028** sqlite3_unlock_notify() results in the unlock-notify callback being 7029** invoked immediately. If the application then re-attempts the "DROP TABLE" 7030** or "DROP INDEX" query, an infinite loop might be the result. 7031** 7032** One way around this problem is to check the extended error code returned 7033** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7034** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7035** the special "DROP TABLE/INDEX" case, the extended error code is just 7036** SQLITE_LOCKED.)^ 7037*/ 7038int sqlite3_unlock_notify( 7039 sqlite3 *pBlocked, /* Waiting connection */ 7040 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7041 void *pNotifyArg /* Argument to pass to xNotify */ 7042); 7043 7044 7045/* 7046** CAPI3REF: String Comparison 7047** 7048** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7049** and extensions to compare the contents of two buffers containing UTF-8 7050** strings in a case-independent fashion, using the same definition of "case 7051** independence" that SQLite uses internally when comparing identifiers. 7052*/ 7053int sqlite3_stricmp(const char *, const char *); 7054int sqlite3_strnicmp(const char *, const char *, int); 7055 7056/* 7057** CAPI3REF: String Globbing 7058* 7059** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7060** the glob pattern P, and it returns non-zero if string X does not match 7061** the glob pattern P. ^The definition of glob pattern matching used in 7062** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7063** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7064** sensitive. 7065** 7066** Note that this routine returns zero on a match and non-zero if the strings 7067** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7068*/ 7069int sqlite3_strglob(const char *zGlob, const char *zStr); 7070 7071/* 7072** CAPI3REF: Error Logging Interface 7073** 7074** ^The [sqlite3_log()] interface writes a message into the [error log] 7075** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7076** ^If logging is enabled, the zFormat string and subsequent arguments are 7077** used with [sqlite3_snprintf()] to generate the final output string. 7078** 7079** The sqlite3_log() interface is intended for use by extensions such as 7080** virtual tables, collating functions, and SQL functions. While there is 7081** nothing to prevent an application from calling sqlite3_log(), doing so 7082** is considered bad form. 7083** 7084** The zFormat string must not be NULL. 7085** 7086** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7087** will not use dynamically allocated memory. The log message is stored in 7088** a fixed-length buffer on the stack. If the log message is longer than 7089** a few hundred characters, it will be truncated to the length of the 7090** buffer. 7091*/ 7092void sqlite3_log(int iErrCode, const char *zFormat, ...); 7093 7094/* 7095** CAPI3REF: Write-Ahead Log Commit Hook 7096** 7097** ^The [sqlite3_wal_hook()] function is used to register a callback that 7098** will be invoked each time a database connection commits data to a 7099** [write-ahead log] (i.e. whenever a transaction is committed in 7100** [journal_mode | journal_mode=WAL mode]). 7101** 7102** ^The callback is invoked by SQLite after the commit has taken place and 7103** the associated write-lock on the database released, so the implementation 7104** may read, write or [checkpoint] the database as required. 7105** 7106** ^The first parameter passed to the callback function when it is invoked 7107** is a copy of the third parameter passed to sqlite3_wal_hook() when 7108** registering the callback. ^The second is a copy of the database handle. 7109** ^The third parameter is the name of the database that was written to - 7110** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7111** is the number of pages currently in the write-ahead log file, 7112** including those that were just committed. 7113** 7114** The callback function should normally return [SQLITE_OK]. ^If an error 7115** code is returned, that error will propagate back up through the 7116** SQLite code base to cause the statement that provoked the callback 7117** to report an error, though the commit will have still occurred. If the 7118** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7119** that does not correspond to any valid SQLite error code, the results 7120** are undefined. 7121** 7122** A single database handle may have at most a single write-ahead log callback 7123** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7124** previously registered write-ahead log callback. ^Note that the 7125** [sqlite3_wal_autocheckpoint()] interface and the 7126** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7127** those overwrite any prior [sqlite3_wal_hook()] settings. 7128*/ 7129void *sqlite3_wal_hook( 7130 sqlite3*, 7131 int(*)(void *,sqlite3*,const char*,int), 7132 void* 7133); 7134 7135/* 7136** CAPI3REF: Configure an auto-checkpoint 7137** 7138** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7139** [sqlite3_wal_hook()] that causes any database on [database connection] D 7140** to automatically [checkpoint] 7141** after committing a transaction if there are N or 7142** more frames in the [write-ahead log] file. ^Passing zero or 7143** a negative value as the nFrame parameter disables automatic 7144** checkpoints entirely. 7145** 7146** ^The callback registered by this function replaces any existing callback 7147** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7148** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7149** configured by this function. 7150** 7151** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7152** from SQL. 7153** 7154** ^Checkpoints initiated by this mechanism are 7155** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7156** 7157** ^Every new [database connection] defaults to having the auto-checkpoint 7158** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7159** pages. The use of this interface 7160** is only necessary if the default setting is found to be suboptimal 7161** for a particular application. 7162*/ 7163int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7164 7165/* 7166** CAPI3REF: Checkpoint a database 7167** 7168** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 7169** on [database connection] D to be [checkpointed]. ^If X is NULL or an 7170** empty string, then a checkpoint is run on all databases of 7171** connection D. ^If the database connection D is not in 7172** [WAL | write-ahead log mode] then this interface is a harmless no-op. 7173** ^The [sqlite3_wal_checkpoint(D,X)] interface initiates a 7174** [sqlite3_wal_checkpoint_v2|PASSIVE] checkpoint. 7175** Use the [sqlite3_wal_checkpoint_v2()] interface to get a FULL 7176** or RESET checkpoint. 7177** 7178** ^The [wal_checkpoint pragma] can be used to invoke this interface 7179** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 7180** [wal_autocheckpoint pragma] can be used to cause this interface to be 7181** run whenever the WAL reaches a certain size threshold. 7182** 7183** See also: [sqlite3_wal_checkpoint_v2()] 7184*/ 7185int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7186 7187/* 7188** CAPI3REF: Checkpoint a database 7189** 7190** Run a checkpoint operation on WAL database zDb attached to database 7191** handle db. The specific operation is determined by the value of the 7192** eMode parameter: 7193** 7194** <dl> 7195** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7196** Checkpoint as many frames as possible without waiting for any database 7197** readers or writers to finish. Sync the db file if all frames in the log 7198** are checkpointed. This mode is the same as calling 7199** sqlite3_wal_checkpoint(). The [sqlite3_busy_handler|busy-handler callback] 7200** is never invoked. 7201** 7202** <dt>SQLITE_CHECKPOINT_FULL<dd> 7203** This mode blocks (it invokes the 7204** [sqlite3_busy_handler|busy-handler callback]) until there is no 7205** database writer and all readers are reading from the most recent database 7206** snapshot. It then checkpoints all frames in the log file and syncs the 7207** database file. This call blocks database writers while it is running, 7208** but not database readers. 7209** 7210** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7211** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7212** checkpointing the log file it blocks (calls the 7213** [sqlite3_busy_handler|busy-handler callback]) 7214** until all readers are reading from the database file only. This ensures 7215** that the next client to write to the database file restarts the log file 7216** from the beginning. This call blocks database writers while it is running, 7217** but not database readers. 7218** </dl> 7219** 7220** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7221** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7222** the total number of checkpointed frames (including any that were already 7223** checkpointed when this function is called). *pnLog and *pnCkpt may be 7224** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7225** If no values are available because of an error, they are both set to -1 7226** before returning to communicate this to the caller. 7227** 7228** All calls obtain an exclusive "checkpoint" lock on the database file. If 7229** any other process is running a checkpoint operation at the same time, the 7230** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7231** busy-handler configured, it will not be invoked in this case. 7232** 7233** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7234** "writer" lock on the database file. If the writer lock cannot be obtained 7235** immediately, and a busy-handler is configured, it is invoked and the writer 7236** lock retried until either the busy-handler returns 0 or the lock is 7237** successfully obtained. The busy-handler is also invoked while waiting for 7238** database readers as described above. If the busy-handler returns 0 before 7239** the writer lock is obtained or while waiting for database readers, the 7240** checkpoint operation proceeds from that point in the same way as 7241** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7242** without blocking any further. SQLITE_BUSY is returned in this case. 7243** 7244** If parameter zDb is NULL or points to a zero length string, then the 7245** specified operation is attempted on all WAL databases. In this case the 7246** values written to output parameters *pnLog and *pnCkpt are undefined. If 7247** an SQLITE_BUSY error is encountered when processing one or more of the 7248** attached WAL databases, the operation is still attempted on any remaining 7249** attached databases and SQLITE_BUSY is returned to the caller. If any other 7250** error occurs while processing an attached database, processing is abandoned 7251** and the error code returned to the caller immediately. If no error 7252** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7253** databases, SQLITE_OK is returned. 7254** 7255** If database zDb is the name of an attached database that is not in WAL 7256** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7257** zDb is not NULL (or a zero length string) and is not the name of any 7258** attached database, SQLITE_ERROR is returned to the caller. 7259*/ 7260int sqlite3_wal_checkpoint_v2( 7261 sqlite3 *db, /* Database handle */ 7262 const char *zDb, /* Name of attached database (or NULL) */ 7263 int eMode, /* SQLITE_CHECKPOINT_* value */ 7264 int *pnLog, /* OUT: Size of WAL log in frames */ 7265 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7266); 7267 7268/* 7269** CAPI3REF: Checkpoint operation parameters 7270** 7271** These constants can be used as the 3rd parameter to 7272** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7273** documentation for additional information about the meaning and use of 7274** each of these values. 7275*/ 7276#define SQLITE_CHECKPOINT_PASSIVE 0 7277#define SQLITE_CHECKPOINT_FULL 1 7278#define SQLITE_CHECKPOINT_RESTART 2 7279 7280/* 7281** CAPI3REF: Virtual Table Interface Configuration 7282** 7283** This function may be called by either the [xConnect] or [xCreate] method 7284** of a [virtual table] implementation to configure 7285** various facets of the virtual table interface. 7286** 7287** If this interface is invoked outside the context of an xConnect or 7288** xCreate virtual table method then the behavior is undefined. 7289** 7290** At present, there is only one option that may be configured using 7291** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7292** may be added in the future. 7293*/ 7294int sqlite3_vtab_config(sqlite3*, int op, ...); 7295 7296/* 7297** CAPI3REF: Virtual Table Configuration Options 7298** 7299** These macros define the various options to the 7300** [sqlite3_vtab_config()] interface that [virtual table] implementations 7301** can use to customize and optimize their behavior. 7302** 7303** <dl> 7304** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7305** <dd>Calls of the form 7306** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7307** where X is an integer. If X is zero, then the [virtual table] whose 7308** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7309** support constraints. In this configuration (which is the default) if 7310** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7311** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7312** specified as part of the users SQL statement, regardless of the actual 7313** ON CONFLICT mode specified. 7314** 7315** If X is non-zero, then the virtual table implementation guarantees 7316** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7317** any modifications to internal or persistent data structures have been made. 7318** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7319** is able to roll back a statement or database transaction, and abandon 7320** or continue processing the current SQL statement as appropriate. 7321** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7322** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7323** had been ABORT. 7324** 7325** Virtual table implementations that are required to handle OR REPLACE 7326** must do so within the [xUpdate] method. If a call to the 7327** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7328** CONFLICT policy is REPLACE, the virtual table implementation should 7329** silently replace the appropriate rows within the xUpdate callback and 7330** return SQLITE_OK. Or, if this is not possible, it may return 7331** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7332** constraint handling. 7333** </dl> 7334*/ 7335#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7336 7337/* 7338** CAPI3REF: Determine The Virtual Table Conflict Policy 7339** 7340** This function may only be called from within a call to the [xUpdate] method 7341** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7342** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7343** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7344** of the SQL statement that triggered the call to the [xUpdate] method of the 7345** [virtual table]. 7346*/ 7347int sqlite3_vtab_on_conflict(sqlite3 *); 7348 7349/* 7350** CAPI3REF: Conflict resolution modes 7351** KEYWORDS: {conflict resolution mode} 7352** 7353** These constants are returned by [sqlite3_vtab_on_conflict()] to 7354** inform a [virtual table] implementation what the [ON CONFLICT] mode 7355** is for the SQL statement being evaluated. 7356** 7357** Note that the [SQLITE_IGNORE] constant is also used as a potential 7358** return value from the [sqlite3_set_authorizer()] callback and that 7359** [SQLITE_ABORT] is also a [result code]. 7360*/ 7361#define SQLITE_ROLLBACK 1 7362/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7363#define SQLITE_FAIL 3 7364/* #define SQLITE_ABORT 4 // Also an error code */ 7365#define SQLITE_REPLACE 5 7366 7367 7368 7369/* 7370** Undo the hack that converts floating point types to integer for 7371** builds on processors without floating point support. 7372*/ 7373#ifdef SQLITE_OMIT_FLOATING_POINT 7374# undef double 7375#endif 7376 7377#ifdef __cplusplus 7378} /* End of the 'extern "C"' block */ 7379#endif 7380#endif /* _SQLITE3_H_ */ 7381