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Diffstat (limited to 'src/sqlite.h.in')
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diff --git a/src/sqlite.h.in b/src/sqlite.h.in new file mode 100644 index 0000000..ed18330 --- /dev/null +++ b/src/sqlite.h.in @@ -0,0 +1,6732 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This header file defines the interface that the SQLite library +** presents to client programs. If a C-function, structure, datatype, +** or constant definition does not appear in this file, then it is +** not a published API of SQLite, is subject to change without +** notice, and should not be referenced by programs that use SQLite. +** +** Some of the definitions that are in this file are marked as +** "experimental". Experimental interfaces are normally new +** features recently added to SQLite. We do not anticipate changes +** to experimental interfaces but reserve the right to make minor changes +** if experience from use "in the wild" suggest such changes are prudent. +** +** The official C-language API documentation for SQLite is derived +** from comments in this file. This file is the authoritative source +** on how SQLite interfaces are suppose to operate. +** +** The name of this file under configuration management is "sqlite.h.in". +** The makefile makes some minor changes to this file (such as inserting +** the version number) and changes its name to "sqlite3.h" as +** part of the build process. +*/ +#ifndef _SQLITE3_H_ +#define _SQLITE3_H_ +#include <stdarg.h> /* Needed for the definition of va_list */ + +/* +** Make sure we can call this stuff from C++. +*/ +#ifdef __cplusplus +extern "C" { +#endif + + +/* +** Add the ability to override 'extern' +*/ +#ifndef SQLITE_EXTERN +# define SQLITE_EXTERN extern +#endif + +/* +** These no-op macros are used in front of interfaces to mark those +** interfaces as either deprecated or experimental. New applications +** should not use deprecated interfaces - they are support for backwards +** compatibility only. Application writers should be aware that +** experimental interfaces are subject to change in point releases. +** +** These macros used to resolve to various kinds of compiler magic that +** would generate warning messages when they were used. But that +** compiler magic ended up generating such a flurry of bug reports +** that we have taken it all out and gone back to using simple +** noop macros. +*/ +#define SQLITE_DEPRECATED +#define SQLITE_EXPERIMENTAL + +/* +** Ensure these symbols were not defined by some previous header file. +*/ +#ifdef SQLITE_VERSION +# undef SQLITE_VERSION +#endif +#ifdef SQLITE_VERSION_NUMBER +# undef SQLITE_VERSION_NUMBER +#endif + +/* +** CAPI3REF: Compile-Time Library Version Numbers +** +** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header +** evaluates to a string literal that is the SQLite version in the +** format "X.Y.Z" where X is the major version number (always 3 for +** SQLite3) and Y is the minor version number and Z is the release number.)^ +** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer +** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same +** numbers used in [SQLITE_VERSION].)^ +** The SQLITE_VERSION_NUMBER for any given release of SQLite will also +** be larger than the release from which it is derived. Either Y will +** be held constant and Z will be incremented or else Y will be incremented +** and Z will be reset to zero. +** +** Since version 3.6.18, SQLite source code has been stored in the +** <a href="http://www.fossil-scm.org/">Fossil configuration management +** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to +** a string which identifies a particular check-in of SQLite +** within its configuration management system. ^The SQLITE_SOURCE_ID +** string contains the date and time of the check-in (UTC) and an SHA1 +** hash of the entire source tree. +** +** See also: [sqlite3_libversion()], +** [sqlite3_libversion_number()], [sqlite3_sourceid()], +** [sqlite_version()] and [sqlite_source_id()]. +*/ +#define SQLITE_VERSION "--VERS--" +#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- +#define SQLITE_SOURCE_ID "--SOURCE-ID--" + +/* +** CAPI3REF: Run-Time Library Version Numbers +** KEYWORDS: sqlite3_version, sqlite3_sourceid +** +** These interfaces provide the same information as the [SQLITE_VERSION], +** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros +** but are associated with the library instead of the header file. ^(Cautious +** programmers might include assert() statements in their application to +** verify that values returned by these interfaces match the macros in +** the header, and thus insure that the application is +** compiled with matching library and header files. +** +** <blockquote><pre> +** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); +** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); +** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); +** </pre></blockquote>)^ +** +** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] +** macro. ^The sqlite3_libversion() function returns a pointer to the +** to the sqlite3_version[] string constant. The sqlite3_libversion() +** function is provided for use in DLLs since DLL users usually do not have +** direct access to string constants within the DLL. ^The +** sqlite3_libversion_number() function returns an integer equal to +** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns +** a pointer to a string constant whose value is the same as the +** [SQLITE_SOURCE_ID] C preprocessor macro. +** +** See also: [sqlite_version()] and [sqlite_source_id()]. +*/ +SQLITE_EXTERN const char sqlite3_version[]; +const char *sqlite3_libversion(void); +const char *sqlite3_sourceid(void); +int sqlite3_libversion_number(void); + +/* +** CAPI3REF: Run-Time Library Compilation Options Diagnostics +** +** ^The sqlite3_compileoption_used() function returns 0 or 1 +** indicating whether the specified option was defined at +** compile time. ^The SQLITE_ prefix may be omitted from the +** option name passed to sqlite3_compileoption_used(). +** +** ^The sqlite3_compileoption_get() function allows iterating +** over the list of options that were defined at compile time by +** returning the N-th compile time option string. ^If N is out of range, +** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ +** prefix is omitted from any strings returned by +** sqlite3_compileoption_get(). +** +** ^Support for the diagnostic functions sqlite3_compileoption_used() +** and sqlite3_compileoption_get() may be omitted by specifying the +** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. +** +** See also: SQL functions [sqlite_compileoption_used()] and +** [sqlite_compileoption_get()] and the [compile_options pragma]. +*/ +#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS +int sqlite3_compileoption_used(const char *zOptName); +const char *sqlite3_compileoption_get(int N); +#endif + +/* +** CAPI3REF: Test To See If The Library Is Threadsafe +** +** ^The sqlite3_threadsafe() function returns zero if and only if +** SQLite was compiled mutexing code omitted due to the +** [SQLITE_THREADSAFE] compile-time option being set to 0. +** +** SQLite can be compiled with or without mutexes. When +** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes +** are enabled and SQLite is threadsafe. When the +** [SQLITE_THREADSAFE] macro is 0, +** the mutexes are omitted. Without the mutexes, it is not safe +** to use SQLite concurrently from more than one thread. +** +** Enabling mutexes incurs a measurable performance penalty. +** So if speed is of utmost importance, it makes sense to disable +** the mutexes. But for maximum safety, mutexes should be enabled. +** ^The default behavior is for mutexes to be enabled. +** +** This interface can be used by an application to make sure that the +** version of SQLite that it is linking against was compiled with +** the desired setting of the [SQLITE_THREADSAFE] macro. +** +** This interface only reports on the compile-time mutex setting +** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with +** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but +** can be fully or partially disabled using a call to [sqlite3_config()] +** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], +** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the +** sqlite3_threadsafe() function shows only the compile-time setting of +** thread safety, not any run-time changes to that setting made by +** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() +** is unchanged by calls to sqlite3_config().)^ +** +** See the [threading mode] documentation for additional information. +*/ +int sqlite3_threadsafe(void); + +/* +** CAPI3REF: Database Connection Handle +** KEYWORDS: {database connection} {database connections} +** +** Each open SQLite database is represented by a pointer to an instance of +** the opaque structure named "sqlite3". It is useful to think of an sqlite3 +** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and +** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] +** is its destructor. There are many other interfaces (such as +** [sqlite3_prepare_v2()], [sqlite3_create_function()], and +** [sqlite3_busy_timeout()] to name but three) that are methods on an +** sqlite3 object. +*/ +typedef struct sqlite3 sqlite3; + +/* +** CAPI3REF: 64-Bit Integer Types +** KEYWORDS: sqlite_int64 sqlite_uint64 +** +** Because there is no cross-platform way to specify 64-bit integer types +** SQLite includes typedefs for 64-bit signed and unsigned integers. +** +** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. +** The sqlite_int64 and sqlite_uint64 types are supported for backwards +** compatibility only. +** +** ^The sqlite3_int64 and sqlite_int64 types can store integer values +** between -9223372036854775808 and +9223372036854775807 inclusive. ^The +** sqlite3_uint64 and sqlite_uint64 types can store integer values +** between 0 and +18446744073709551615 inclusive. +*/ +#ifdef SQLITE_INT64_TYPE + typedef SQLITE_INT64_TYPE sqlite_int64; + typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; +#elif defined(_MSC_VER) || defined(__BORLANDC__) + typedef __int64 sqlite_int64; + typedef unsigned __int64 sqlite_uint64; +#else + typedef long long int sqlite_int64; + typedef unsigned long long int sqlite_uint64; +#endif +typedef sqlite_int64 sqlite3_int64; +typedef sqlite_uint64 sqlite3_uint64; + +/* +** If compiling for a processor that lacks floating point support, +** substitute integer for floating-point. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# define double sqlite3_int64 +#endif + +/* +** CAPI3REF: Closing A Database Connection +** +** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. +** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is +** successfully destroyed and all associated resources are deallocated. +** +** Applications must [sqlite3_finalize | finalize] all [prepared statements] +** and [sqlite3_blob_close | close] all [BLOB handles] associated with +** the [sqlite3] object prior to attempting to close the object. ^If +** sqlite3_close() is called on a [database connection] that still has +** outstanding [prepared statements] or [BLOB handles], then it returns +** SQLITE_BUSY. +** +** ^If [sqlite3_close()] is invoked while a transaction is open, +** the transaction is automatically rolled back. +** +** The C parameter to [sqlite3_close(C)] must be either a NULL +** pointer or an [sqlite3] object pointer obtained +** from [sqlite3_open()], [sqlite3_open16()], or +** [sqlite3_open_v2()], and not previously closed. +** ^Calling sqlite3_close() with a NULL pointer argument is a +** harmless no-op. +*/ +int sqlite3_close(sqlite3 *); + +/* +** The type for a callback function. +** This is legacy and deprecated. It is included for historical +** compatibility and is not documented. +*/ +typedef int (*sqlite3_callback)(void*,int,char**, char**); + +/* +** CAPI3REF: One-Step Query Execution Interface +** +** The sqlite3_exec() interface is a convenience wrapper around +** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], +** that allows an application to run multiple statements of SQL +** without having to use a lot of C code. +** +** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, +** semicolon-separate SQL statements passed into its 2nd argument, +** in the context of the [database connection] passed in as its 1st +** argument. ^If the callback function of the 3rd argument to +** sqlite3_exec() is not NULL, then it is invoked for each result row +** coming out of the evaluated SQL statements. ^The 4th argument to +** sqlite3_exec() is relayed through to the 1st argument of each +** callback invocation. ^If the callback pointer to sqlite3_exec() +** is NULL, then no callback is ever invoked and result rows are +** ignored. +** +** ^If an error occurs while evaluating the SQL statements passed into +** sqlite3_exec(), then execution of the current statement stops and +** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() +** is not NULL then any error message is written into memory obtained +** from [sqlite3_malloc()] and passed back through the 5th parameter. +** To avoid memory leaks, the application should invoke [sqlite3_free()] +** on error message strings returned through the 5th parameter of +** of sqlite3_exec() after the error message string is no longer needed. +** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors +** occur, then sqlite3_exec() sets the pointer in its 5th parameter to +** NULL before returning. +** +** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() +** routine returns SQLITE_ABORT without invoking the callback again and +** without running any subsequent SQL statements. +** +** ^The 2nd argument to the sqlite3_exec() callback function is the +** number of columns in the result. ^The 3rd argument to the sqlite3_exec() +** callback is an array of pointers to strings obtained as if from +** [sqlite3_column_text()], one for each column. ^If an element of a +** result row is NULL then the corresponding string pointer for the +** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the +** sqlite3_exec() callback is an array of pointers to strings where each +** entry represents the name of corresponding result column as obtained +** from [sqlite3_column_name()]. +** +** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer +** to an empty string, or a pointer that contains only whitespace and/or +** SQL comments, then no SQL statements are evaluated and the database +** is not changed. +** +** Restrictions: +** +** <ul> +** <li> The application must insure that the 1st parameter to sqlite3_exec() +** is a valid and open [database connection]. +** <li> The application must not close [database connection] specified by +** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. +** <li> The application must not modify the SQL statement text passed into +** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. +** </ul> +*/ +int sqlite3_exec( + sqlite3*, /* An open database */ + const char *sql, /* SQL to be evaluated */ + int (*callback)(void*,int,char**,char**), /* Callback function */ + void *, /* 1st argument to callback */ + char **errmsg /* Error msg written here */ +); + +/* +** CAPI3REF: Result Codes +** KEYWORDS: SQLITE_OK {error code} {error codes} +** KEYWORDS: {result code} {result codes} +** +** Many SQLite functions return an integer result code from the set shown +** here in order to indicates success or failure. +** +** New error codes may be added in future versions of SQLite. +** +** See also: [SQLITE_IOERR_READ | extended result codes], +** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. +*/ +#define SQLITE_OK 0 /* Successful result */ +/* beginning-of-error-codes */ +#define SQLITE_ERROR 1 /* SQL error or missing database */ +#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ +#define SQLITE_PERM 3 /* Access permission denied */ +#define SQLITE_ABORT 4 /* Callback routine requested an abort */ +#define SQLITE_BUSY 5 /* The database file is locked */ +#define SQLITE_LOCKED 6 /* A table in the database is locked */ +#define SQLITE_NOMEM 7 /* A malloc() failed */ +#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ +#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ +#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ +#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ +#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ +#define SQLITE_FULL 13 /* Insertion failed because database is full */ +#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ +#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ +#define SQLITE_EMPTY 16 /* Database is empty */ +#define SQLITE_SCHEMA 17 /* The database schema changed */ +#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ +#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ +#define SQLITE_MISMATCH 20 /* Data type mismatch */ +#define SQLITE_MISUSE 21 /* Library used incorrectly */ +#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ +#define SQLITE_AUTH 23 /* Authorization denied */ +#define SQLITE_FORMAT 24 /* Auxiliary database format error */ +#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ +#define SQLITE_NOTADB 26 /* File opened that is not a database file */ +#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ +#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ +/* end-of-error-codes */ + +/* +** CAPI3REF: Extended Result Codes +** KEYWORDS: {extended error code} {extended error codes} +** KEYWORDS: {extended result code} {extended result codes} +** +** In its default configuration, SQLite API routines return one of 26 integer +** [SQLITE_OK | result codes]. However, experience has shown that many of +** these result codes are too coarse-grained. They do not provide as +** much information about problems as programmers might like. In an effort to +** address this, newer versions of SQLite (version 3.3.8 and later) include +** support for additional result codes that provide more detailed information +** about errors. The extended result codes are enabled or disabled +** on a per database connection basis using the +** [sqlite3_extended_result_codes()] API. +** +** Some of the available extended result codes are listed here. +** One may expect the number of extended result codes will be expand +** over time. Software that uses extended result codes should expect +** to see new result codes in future releases of SQLite. +** +** The SQLITE_OK result code will never be extended. It will always +** be exactly zero. +*/ +#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) +#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) +#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) +#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) +#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) +#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) +#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) +#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) +#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) +#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) +#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) +#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) +#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) +#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) +#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) +#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) +#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) +#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) +#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) +#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) +#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) +#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) +#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) +#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) +#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) +#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) +#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) +#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) + +/* +** CAPI3REF: Flags For File Open Operations +** +** These bit values are intended for use in the +** 3rd parameter to the [sqlite3_open_v2()] interface and +** in the 4th parameter to the [sqlite3_vfs.xOpen] method. +*/ +#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ +#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ +#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ +#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ +#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ +#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ +#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ +#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ +#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ +#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ +#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ +#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ + +/* Reserved: 0x00F00000 */ + +/* +** CAPI3REF: Device Characteristics +** +** The xDeviceCharacteristics method of the [sqlite3_io_methods] +** object returns an integer which is a vector of the these +** bit values expressing I/O characteristics of the mass storage +** device that holds the file that the [sqlite3_io_methods] +** refers to. +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). +*/ +#define SQLITE_IOCAP_ATOMIC 0x00000001 +#define SQLITE_IOCAP_ATOMIC512 0x00000002 +#define SQLITE_IOCAP_ATOMIC1K 0x00000004 +#define SQLITE_IOCAP_ATOMIC2K 0x00000008 +#define SQLITE_IOCAP_ATOMIC4K 0x00000010 +#define SQLITE_IOCAP_ATOMIC8K 0x00000020 +#define SQLITE_IOCAP_ATOMIC16K 0x00000040 +#define SQLITE_IOCAP_ATOMIC32K 0x00000080 +#define SQLITE_IOCAP_ATOMIC64K 0x00000100 +#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 +#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 +#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 + +/* +** CAPI3REF: File Locking Levels +** +** SQLite uses one of these integer values as the second +** argument to calls it makes to the xLock() and xUnlock() methods +** of an [sqlite3_io_methods] object. +*/ +#define SQLITE_LOCK_NONE 0 +#define SQLITE_LOCK_SHARED 1 +#define SQLITE_LOCK_RESERVED 2 +#define SQLITE_LOCK_PENDING 3 +#define SQLITE_LOCK_EXCLUSIVE 4 + +/* +** CAPI3REF: Synchronization Type Flags +** +** When SQLite invokes the xSync() method of an +** [sqlite3_io_methods] object it uses a combination of +** these integer values as the second argument. +** +** When the SQLITE_SYNC_DATAONLY flag is used, it means that the +** sync operation only needs to flush data to mass storage. Inode +** information need not be flushed. If the lower four bits of the flag +** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. +** If the lower four bits equal SQLITE_SYNC_FULL, that means +** to use Mac OS X style fullsync instead of fsync(). +** +** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags +** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL +** settings. The [synchronous pragma] determines when calls to the +** xSync VFS method occur and applies uniformly across all platforms. +** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how +** energetic or rigorous or forceful the sync operations are and +** only make a difference on Mac OSX for the default SQLite code. +** (Third-party VFS implementations might also make the distinction +** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the +** operating systems natively supported by SQLite, only Mac OSX +** cares about the difference.) +*/ +#define SQLITE_SYNC_NORMAL 0x00002 +#define SQLITE_SYNC_FULL 0x00003 +#define SQLITE_SYNC_DATAONLY 0x00010 + +/* +** CAPI3REF: OS Interface Open File Handle +** +** An [sqlite3_file] object represents an open file in the +** [sqlite3_vfs | OS interface layer]. Individual OS interface +** implementations will +** want to subclass this object by appending additional fields +** for their own use. The pMethods entry is a pointer to an +** [sqlite3_io_methods] object that defines methods for performing +** I/O operations on the open file. +*/ +typedef struct sqlite3_file sqlite3_file; +struct sqlite3_file { + const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ +}; + +/* +** CAPI3REF: OS Interface File Virtual Methods Object +** +** Every file opened by the [sqlite3_vfs.xOpen] method populates an +** [sqlite3_file] object (or, more commonly, a subclass of the +** [sqlite3_file] object) with a pointer to an instance of this object. +** This object defines the methods used to perform various operations +** against the open file represented by the [sqlite3_file] object. +** +** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element +** to a non-NULL pointer, then the sqlite3_io_methods.xClose method +** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The +** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] +** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element +** to NULL. +** +** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or +** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). +** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] +** flag may be ORed in to indicate that only the data of the file +** and not its inode needs to be synced. +** +** The integer values to xLock() and xUnlock() are one of +** <ul> +** <li> [SQLITE_LOCK_NONE], +** <li> [SQLITE_LOCK_SHARED], +** <li> [SQLITE_LOCK_RESERVED], +** <li> [SQLITE_LOCK_PENDING], or +** <li> [SQLITE_LOCK_EXCLUSIVE]. +** </ul> +** xLock() increases the lock. xUnlock() decreases the lock. +** The xCheckReservedLock() method checks whether any database connection, +** either in this process or in some other process, is holding a RESERVED, +** PENDING, or EXCLUSIVE lock on the file. It returns true +** if such a lock exists and false otherwise. +** +** The xFileControl() method is a generic interface that allows custom +** VFS implementations to directly control an open file using the +** [sqlite3_file_control()] interface. The second "op" argument is an +** integer opcode. The third argument is a generic pointer intended to +** point to a structure that may contain arguments or space in which to +** write return values. Potential uses for xFileControl() might be +** functions to enable blocking locks with timeouts, to change the +** locking strategy (for example to use dot-file locks), to inquire +** about the status of a lock, or to break stale locks. The SQLite +** core reserves all opcodes less than 100 for its own use. +** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. +** Applications that define a custom xFileControl method should use opcodes +** greater than 100 to avoid conflicts. VFS implementations should +** return [SQLITE_NOTFOUND] for file control opcodes that they do not +** recognize. +** +** The xSectorSize() method returns the sector size of the +** device that underlies the file. The sector size is the +** minimum write that can be performed without disturbing +** other bytes in the file. The xDeviceCharacteristics() +** method returns a bit vector describing behaviors of the +** underlying device: +** +** <ul> +** <li> [SQLITE_IOCAP_ATOMIC] +** <li> [SQLITE_IOCAP_ATOMIC512] +** <li> [SQLITE_IOCAP_ATOMIC1K] +** <li> [SQLITE_IOCAP_ATOMIC2K] +** <li> [SQLITE_IOCAP_ATOMIC4K] +** <li> [SQLITE_IOCAP_ATOMIC8K] +** <li> [SQLITE_IOCAP_ATOMIC16K] +** <li> [SQLITE_IOCAP_ATOMIC32K] +** <li> [SQLITE_IOCAP_ATOMIC64K] +** <li> [SQLITE_IOCAP_SAFE_APPEND] +** <li> [SQLITE_IOCAP_SEQUENTIAL] +** </ul> +** +** The SQLITE_IOCAP_ATOMIC property means that all writes of +** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values +** mean that writes of blocks that are nnn bytes in size and +** are aligned to an address which is an integer multiple of +** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means +** that when data is appended to a file, the data is appended +** first then the size of the file is extended, never the other +** way around. The SQLITE_IOCAP_SEQUENTIAL property means that +** information is written to disk in the same order as calls +** to xWrite(). +** +** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill +** in the unread portions of the buffer with zeros. A VFS that +** fails to zero-fill short reads might seem to work. However, +** failure to zero-fill short reads will eventually lead to +** database corruption. +*/ +typedef struct sqlite3_io_methods sqlite3_io_methods; +struct sqlite3_io_methods { + int iVersion; + int (*xClose)(sqlite3_file*); + int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); + int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); + int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); + int (*xSync)(sqlite3_file*, int flags); + int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); + int (*xLock)(sqlite3_file*, int); + int (*xUnlock)(sqlite3_file*, int); + int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); + int (*xFileControl)(sqlite3_file*, int op, void *pArg); + int (*xSectorSize)(sqlite3_file*); + int (*xDeviceCharacteristics)(sqlite3_file*); + /* Methods above are valid for version 1 */ + int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); + int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); + void (*xShmBarrier)(sqlite3_file*); + int (*xShmUnmap)(sqlite3_file*, int deleteFlag); + /* Methods above are valid for version 2 */ + /* Additional methods may be added in future releases */ +}; + +/* +** CAPI3REF: Standard File Control Opcodes +** +** These integer constants are opcodes for the xFileControl method +** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] +** interface. +** +** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This +** opcode causes the xFileControl method to write the current state of +** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], +** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) +** into an integer that the pArg argument points to. This capability +** is used during testing and only needs to be supported when SQLITE_TEST +** is defined. +** +** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS +** layer a hint of how large the database file will grow to be during the +** current transaction. This hint is not guaranteed to be accurate but it +** is often close. The underlying VFS might choose to preallocate database +** file space based on this hint in order to help writes to the database +** file run faster. +** +** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS +** extends and truncates the database file in chunks of a size specified +** by the user. The fourth argument to [sqlite3_file_control()] should +** point to an integer (type int) containing the new chunk-size to use +** for the nominated database. Allocating database file space in large +** chunks (say 1MB at a time), may reduce file-system fragmentation and +** improve performance on some systems. +** +** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer +** to the [sqlite3_file] object associated with a particular database +** connection. See the [sqlite3_file_control()] documentation for +** additional information. +** +** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by +** SQLite and sent to all VFSes in place of a call to the xSync method +** when the database connection has [PRAGMA synchronous] set to OFF.)^ +** Some specialized VFSes need this signal in order to operate correctly +** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most +** VFSes do not need this signal and should silently ignore this opcode. +** Applications should not call [sqlite3_file_control()] with this +** opcode as doing so may disrupt the operation of the specialized VFSes +** that do require it. +** +** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic +** retry counts and intervals for certain disk I/O operations for the +** windows [VFS] in order to work to provide robustness against +** anti-virus programs. By default, the windows VFS will retry file read, +** file write, and file delete operations up to 10 times, with a delay +** of 25 milliseconds before the first retry and with the delay increasing +** by an additional 25 milliseconds with each subsequent retry. This +** opcode allows those to values (10 retries and 25 milliseconds of delay) +** to be adjusted. The values are changed for all database connections +** within the same process. The argument is a pointer to an array of two +** integers where the first integer i the new retry count and the second +** integer is the delay. If either integer is negative, then the setting +** is not changed but instead the prior value of that setting is written +** into the array entry, allowing the current retry settings to be +** interrogated. The zDbName parameter is ignored. +** +** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the +** persistent [WAL | Write AHead Log] setting. By default, the auxiliary +** write ahead log and shared memory files used for transaction control +** are automatically deleted when the latest connection to the database +** closes. Setting persistent WAL mode causes those files to persist after +** close. Persisting the files is useful when other processes that do not +** have write permission on the directory containing the database file want +** to read the database file, as the WAL and shared memory files must exist +** in order for the database to be readable. The fourth parameter to +** [sqlite3_file_control()] for this opcode should be a pointer to an integer. +** That integer is 0 to disable persistent WAL mode or 1 to enable persistent +** WAL mode. If the integer is -1, then it is overwritten with the current +** WAL persistence setting. +** +** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening +** a write transaction to indicate that, unless it is rolled back for some +** reason, the entire database file will be overwritten by the current +** transaction. This is used by VACUUM operations. +*/ +#define SQLITE_FCNTL_LOCKSTATE 1 +#define SQLITE_GET_LOCKPROXYFILE 2 +#define SQLITE_SET_LOCKPROXYFILE 3 +#define SQLITE_LAST_ERRNO 4 +#define SQLITE_FCNTL_SIZE_HINT 5 +#define SQLITE_FCNTL_CHUNK_SIZE 6 +#define SQLITE_FCNTL_FILE_POINTER 7 +#define SQLITE_FCNTL_SYNC_OMITTED 8 +#define SQLITE_FCNTL_WIN32_AV_RETRY 9 +#define SQLITE_FCNTL_PERSIST_WAL 10 +#define SQLITE_FCNTL_OVERWRITE 11 + +/* +** CAPI3REF: Mutex Handle +** +** The mutex module within SQLite defines [sqlite3_mutex] to be an +** abstract type for a mutex object. The SQLite core never looks +** at the internal representation of an [sqlite3_mutex]. It only +** deals with pointers to the [sqlite3_mutex] object. +** +** Mutexes are created using [sqlite3_mutex_alloc()]. +*/ +typedef struct sqlite3_mutex sqlite3_mutex; + +/* +** CAPI3REF: OS Interface Object +** +** An instance of the sqlite3_vfs object defines the interface between +** the SQLite core and the underlying operating system. The "vfs" +** in the name of the object stands for "virtual file system". See +** the [VFS | VFS documentation] for further information. +** +** The value of the iVersion field is initially 1 but may be larger in +** future versions of SQLite. Additional fields may be appended to this +** object when the iVersion value is increased. Note that the structure +** of the sqlite3_vfs object changes in the transaction between +** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not +** modified. +** +** The szOsFile field is the size of the subclassed [sqlite3_file] +** structure used by this VFS. mxPathname is the maximum length of +** a pathname in this VFS. +** +** Registered sqlite3_vfs objects are kept on a linked list formed by +** the pNext pointer. The [sqlite3_vfs_register()] +** and [sqlite3_vfs_unregister()] interfaces manage this list +** in a thread-safe way. The [sqlite3_vfs_find()] interface +** searches the list. Neither the application code nor the VFS +** implementation should use the pNext pointer. +** +** The pNext field is the only field in the sqlite3_vfs +** structure that SQLite will ever modify. SQLite will only access +** or modify this field while holding a particular static mutex. +** The application should never modify anything within the sqlite3_vfs +** object once the object has been registered. +** +** The zName field holds the name of the VFS module. The name must +** be unique across all VFS modules. +** +** [[sqlite3_vfs.xOpen]] +** ^SQLite guarantees that the zFilename parameter to xOpen +** is either a NULL pointer or string obtained +** from xFullPathname() with an optional suffix added. +** ^If a suffix is added to the zFilename parameter, it will +** consist of a single "-" character followed by no more than +** 10 alphanumeric and/or "-" characters. +** ^SQLite further guarantees that +** the string will be valid and unchanged until xClose() is +** called. Because of the previous sentence, +** the [sqlite3_file] can safely store a pointer to the +** filename if it needs to remember the filename for some reason. +** If the zFilename parameter to xOpen is a NULL pointer then xOpen +** must invent its own temporary name for the file. ^Whenever the +** xFilename parameter is NULL it will also be the case that the +** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. +** +** The flags argument to xOpen() includes all bits set in +** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] +** or [sqlite3_open16()] is used, then flags includes at least +** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. +** If xOpen() opens a file read-only then it sets *pOutFlags to +** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. +** +** ^(SQLite will also add one of the following flags to the xOpen() +** call, depending on the object being opened: +** +** <ul> +** <li> [SQLITE_OPEN_MAIN_DB] +** <li> [SQLITE_OPEN_MAIN_JOURNAL] +** <li> [SQLITE_OPEN_TEMP_DB] +** <li> [SQLITE_OPEN_TEMP_JOURNAL] +** <li> [SQLITE_OPEN_TRANSIENT_DB] +** <li> [SQLITE_OPEN_SUBJOURNAL] +** <li> [SQLITE_OPEN_MASTER_JOURNAL] +** <li> [SQLITE_OPEN_WAL] +** </ul>)^ +** +** The file I/O implementation can use the object type flags to +** change the way it deals with files. For example, an application +** that does not care about crash recovery or rollback might make +** the open of a journal file a no-op. Writes to this journal would +** also be no-ops, and any attempt to read the journal would return +** SQLITE_IOERR. Or the implementation might recognize that a database +** file will be doing page-aligned sector reads and writes in a random +** order and set up its I/O subsystem accordingly. +** +** SQLite might also add one of the following flags to the xOpen method: +** +** <ul> +** <li> [SQLITE_OPEN_DELETEONCLOSE] +** <li> [SQLITE_OPEN_EXCLUSIVE] +** </ul> +** +** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be +** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] +** will be set for TEMP databases and their journals, transient +** databases, and subjournals. +** +** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction +** with the [SQLITE_OPEN_CREATE] flag, which are both directly +** analogous to the O_EXCL and O_CREAT flags of the POSIX open() +** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the +** SQLITE_OPEN_CREATE, is used to indicate that file should always +** be created, and that it is an error if it already exists. +** It is <i>not</i> used to indicate the file should be opened +** for exclusive access. +** +** ^At least szOsFile bytes of memory are allocated by SQLite +** to hold the [sqlite3_file] structure passed as the third +** argument to xOpen. The xOpen method does not have to +** allocate the structure; it should just fill it in. Note that +** the xOpen method must set the sqlite3_file.pMethods to either +** a valid [sqlite3_io_methods] object or to NULL. xOpen must do +** this even if the open fails. SQLite expects that the sqlite3_file.pMethods +** element will be valid after xOpen returns regardless of the success +** or failure of the xOpen call. +** +** [[sqlite3_vfs.xAccess]] +** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] +** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to +** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] +** to test whether a file is at least readable. The file can be a +** directory. +** +** ^SQLite will always allocate at least mxPathname+1 bytes for the +** output buffer xFullPathname. The exact size of the output buffer +** is also passed as a parameter to both methods. If the output buffer +** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is +** handled as a fatal error by SQLite, vfs implementations should endeavor +** to prevent this by setting mxPathname to a sufficiently large value. +** +** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() +** interfaces are not strictly a part of the filesystem, but they are +** included in the VFS structure for completeness. +** The xRandomness() function attempts to return nBytes bytes +** of good-quality randomness into zOut. The return value is +** the actual number of bytes of randomness obtained. +** The xSleep() method causes the calling thread to sleep for at +** least the number of microseconds given. ^The xCurrentTime() +** method returns a Julian Day Number for the current date and time as +** a floating point value. +** ^The xCurrentTimeInt64() method returns, as an integer, the Julian +** Day Number multiplied by 86400000 (the number of milliseconds in +** a 24-hour day). +** ^SQLite will use the xCurrentTimeInt64() method to get the current +** date and time if that method is available (if iVersion is 2 or +** greater and the function pointer is not NULL) and will fall back +** to xCurrentTime() if xCurrentTimeInt64() is unavailable. +** +** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces +** are not used by the SQLite core. These optional interfaces are provided +** by some VFSes to facilitate testing of the VFS code. By overriding +** system calls with functions under its control, a test program can +** simulate faults and error conditions that would otherwise be difficult +** or impossible to induce. The set of system calls that can be overridden +** varies from one VFS to another, and from one version of the same VFS to the +** next. Applications that use these interfaces must be prepared for any +** or all of these interfaces to be NULL or for their behavior to change +** from one release to the next. Applications must not attempt to access +** any of these methods if the iVersion of the VFS is less than 3. +*/ +typedef struct sqlite3_vfs sqlite3_vfs; +typedef void (*sqlite3_syscall_ptr)(void); +struct sqlite3_vfs { + int iVersion; /* Structure version number (currently 3) */ + int szOsFile; /* Size of subclassed sqlite3_file */ + int mxPathname; /* Maximum file pathname length */ + sqlite3_vfs *pNext; /* Next registered VFS */ + const char *zName; /* Name of this virtual file system */ + void *pAppData; /* Pointer to application-specific data */ + int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, + int flags, int *pOutFlags); + int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); + int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); + int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); + void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); + void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); + void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); + void (*xDlClose)(sqlite3_vfs*, void*); + int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); + int (*xSleep)(sqlite3_vfs*, int microseconds); + int (*xCurrentTime)(sqlite3_vfs*, double*); + int (*xGetLastError)(sqlite3_vfs*, int, char *); + /* + ** The methods above are in version 1 of the sqlite_vfs object + ** definition. Those that follow are added in version 2 or later + */ + int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); + /* + ** The methods above are in versions 1 and 2 of the sqlite_vfs object. + ** Those below are for version 3 and greater. + */ + int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); + sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); + const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); + /* + ** The methods above are in versions 1 through 3 of the sqlite_vfs object. + ** New fields may be appended in figure versions. The iVersion + ** value will increment whenever this happens. + */ +}; + +/* +** CAPI3REF: Flags for the xAccess VFS method +** +** These integer constants can be used as the third parameter to +** the xAccess method of an [sqlite3_vfs] object. They determine +** what kind of permissions the xAccess method is looking for. +** With SQLITE_ACCESS_EXISTS, the xAccess method +** simply checks whether the file exists. +** With SQLITE_ACCESS_READWRITE, the xAccess method +** checks whether the named directory is both readable and writable +** (in other words, if files can be added, removed, and renamed within +** the directory). +** The SQLITE_ACCESS_READWRITE constant is currently used only by the +** [temp_store_directory pragma], though this could change in a future +** release of SQLite. +** With SQLITE_ACCESS_READ, the xAccess method +** checks whether the file is readable. The SQLITE_ACCESS_READ constant is +** currently unused, though it might be used in a future release of +** SQLite. +*/ +#define SQLITE_ACCESS_EXISTS 0 +#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ +#define SQLITE_ACCESS_READ 2 /* Unused */ + +/* +** CAPI3REF: Flags for the xShmLock VFS method +** +** These integer constants define the various locking operations +** allowed by the xShmLock method of [sqlite3_io_methods]. The +** following are the only legal combinations of flags to the +** xShmLock method: +** +** <ul> +** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED +** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE +** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED +** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE +** </ul> +** +** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as +** was given no the corresponding lock. +** +** The xShmLock method can transition between unlocked and SHARED or +** between unlocked and EXCLUSIVE. It cannot transition between SHARED +** and EXCLUSIVE. +*/ +#define SQLITE_SHM_UNLOCK 1 +#define SQLITE_SHM_LOCK 2 +#define SQLITE_SHM_SHARED 4 +#define SQLITE_SHM_EXCLUSIVE 8 + +/* +** CAPI3REF: Maximum xShmLock index +** +** The xShmLock method on [sqlite3_io_methods] may use values +** between 0 and this upper bound as its "offset" argument. +** The SQLite core will never attempt to acquire or release a +** lock outside of this range +*/ +#define SQLITE_SHM_NLOCK 8 + + +/* +** CAPI3REF: Initialize The SQLite Library +** +** ^The sqlite3_initialize() routine initializes the +** SQLite library. ^The sqlite3_shutdown() routine +** deallocates any resources that were allocated by sqlite3_initialize(). +** These routines are designed to aid in process initialization and +** shutdown on embedded systems. Workstation applications using +** SQLite normally do not need to invoke either of these routines. +** +** A call to sqlite3_initialize() is an "effective" call if it is +** the first time sqlite3_initialize() is invoked during the lifetime of +** the process, or if it is the first time sqlite3_initialize() is invoked +** following a call to sqlite3_shutdown(). ^(Only an effective call +** of sqlite3_initialize() does any initialization. All other calls +** are harmless no-ops.)^ +** +** A call to sqlite3_shutdown() is an "effective" call if it is the first +** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only +** an effective call to sqlite3_shutdown() does any deinitialization. +** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ +** +** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() +** is not. The sqlite3_shutdown() interface must only be called from a +** single thread. All open [database connections] must be closed and all +** other SQLite resources must be deallocated prior to invoking +** sqlite3_shutdown(). +** +** Among other things, ^sqlite3_initialize() will invoke +** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() +** will invoke sqlite3_os_end(). +** +** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. +** ^If for some reason, sqlite3_initialize() is unable to initialize +** the library (perhaps it is unable to allocate a needed resource such +** as a mutex) it returns an [error code] other than [SQLITE_OK]. +** +** ^The sqlite3_initialize() routine is called internally by many other +** SQLite interfaces so that an application usually does not need to +** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] +** calls sqlite3_initialize() so the SQLite library will be automatically +** initialized when [sqlite3_open()] is called if it has not be initialized +** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] +** compile-time option, then the automatic calls to sqlite3_initialize() +** are omitted and the application must call sqlite3_initialize() directly +** prior to using any other SQLite interface. For maximum portability, +** it is recommended that applications always invoke sqlite3_initialize() +** directly prior to using any other SQLite interface. Future releases +** of SQLite may require this. In other words, the behavior exhibited +** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the +** default behavior in some future release of SQLite. +** +** The sqlite3_os_init() routine does operating-system specific +** initialization of the SQLite library. The sqlite3_os_end() +** routine undoes the effect of sqlite3_os_init(). Typical tasks +** performed by these routines include allocation or deallocation +** of static resources, initialization of global variables, +** setting up a default [sqlite3_vfs] module, or setting up +** a default configuration using [sqlite3_config()]. +** +** The application should never invoke either sqlite3_os_init() +** or sqlite3_os_end() directly. The application should only invoke +** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() +** interface is called automatically by sqlite3_initialize() and +** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate +** implementations for sqlite3_os_init() and sqlite3_os_end() +** are built into SQLite when it is compiled for Unix, Windows, or OS/2. +** When [custom builds | built for other platforms] +** (using the [SQLITE_OS_OTHER=1] compile-time +** option) the application must supply a suitable implementation for +** sqlite3_os_init() and sqlite3_os_end(). An application-supplied +** implementation of sqlite3_os_init() or sqlite3_os_end() +** must return [SQLITE_OK] on success and some other [error code] upon +** failure. +*/ +int sqlite3_initialize(void); +int sqlite3_shutdown(void); +int sqlite3_os_init(void); +int sqlite3_os_end(void); + +/* +** CAPI3REF: Configuring The SQLite Library +** +** The sqlite3_config() interface is used to make global configuration +** changes to SQLite in order to tune SQLite to the specific needs of +** the application. The default configuration is recommended for most +** applications and so this routine is usually not necessary. It is +** provided to support rare applications with unusual needs. +** +** The sqlite3_config() interface is not threadsafe. The application +** must insure that no other SQLite interfaces are invoked by other +** threads while sqlite3_config() is running. Furthermore, sqlite3_config() +** may only be invoked prior to library initialization using +** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. +** ^If sqlite3_config() is called after [sqlite3_initialize()] and before +** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. +** Note, however, that ^sqlite3_config() can be called as part of the +** implementation of an application-defined [sqlite3_os_init()]. +** +** The first argument to sqlite3_config() is an integer +** [configuration option] that determines +** what property of SQLite is to be configured. Subsequent arguments +** vary depending on the [configuration option] +** in the first argument. +** +** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. +** ^If the option is unknown or SQLite is unable to set the option +** then this routine returns a non-zero [error code]. +*/ +int sqlite3_config(int, ...); + +/* +** CAPI3REF: Configure database connections +** +** The sqlite3_db_config() interface is used to make configuration +** changes to a [database connection]. The interface is similar to +** [sqlite3_config()] except that the changes apply to a single +** [database connection] (specified in the first argument). +** +** The second argument to sqlite3_db_config(D,V,...) is the +** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code +** that indicates what aspect of the [database connection] is being configured. +** Subsequent arguments vary depending on the configuration verb. +** +** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if +** the call is considered successful. +*/ +int sqlite3_db_config(sqlite3*, int op, ...); + +/* +** CAPI3REF: Memory Allocation Routines +** +** An instance of this object defines the interface between SQLite +** and low-level memory allocation routines. +** +** This object is used in only one place in the SQLite interface. +** A pointer to an instance of this object is the argument to +** [sqlite3_config()] when the configuration option is +** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. +** By creating an instance of this object +** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) +** during configuration, an application can specify an alternative +** memory allocation subsystem for SQLite to use for all of its +** dynamic memory needs. +** +** Note that SQLite comes with several [built-in memory allocators] +** that are perfectly adequate for the overwhelming majority of applications +** and that this object is only useful to a tiny minority of applications +** with specialized memory allocation requirements. This object is +** also used during testing of SQLite in order to specify an alternative +** memory allocator that simulates memory out-of-memory conditions in +** order to verify that SQLite recovers gracefully from such +** conditions. +** +** The xMalloc, xRealloc, and xFree methods must work like the +** malloc(), realloc() and free() functions from the standard C library. +** ^SQLite guarantees that the second argument to +** xRealloc is always a value returned by a prior call to xRoundup. +** +** xSize should return the allocated size of a memory allocation +** previously obtained from xMalloc or xRealloc. The allocated size +** is always at least as big as the requested size but may be larger. +** +** The xRoundup method returns what would be the allocated size of +** a memory allocation given a particular requested size. Most memory +** allocators round up memory allocations at least to the next multiple +** of 8. Some allocators round up to a larger multiple or to a power of 2. +** Every memory allocation request coming in through [sqlite3_malloc()] +** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, +** that causes the corresponding memory allocation to fail. +** +** The xInit method initializes the memory allocator. (For example, +** it might allocate any require mutexes or initialize internal data +** structures. The xShutdown method is invoked (indirectly) by +** [sqlite3_shutdown()] and should deallocate any resources acquired +** by xInit. The pAppData pointer is used as the only parameter to +** xInit and xShutdown. +** +** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes +** the xInit method, so the xInit method need not be threadsafe. The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. For all other methods, SQLite +** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the +** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which +** it is by default) and so the methods are automatically serialized. +** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other +** methods must be threadsafe or else make their own arrangements for +** serialization. +** +** SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +*/ +typedef struct sqlite3_mem_methods sqlite3_mem_methods; +struct sqlite3_mem_methods { + void *(*xMalloc)(int); /* Memory allocation function */ + void (*xFree)(void*); /* Free a prior allocation */ + void *(*xRealloc)(void*,int); /* Resize an allocation */ + int (*xSize)(void*); /* Return the size of an allocation */ + int (*xRoundup)(int); /* Round up request size to allocation size */ + int (*xInit)(void*); /* Initialize the memory allocator */ + void (*xShutdown)(void*); /* Deinitialize the memory allocator */ + void *pAppData; /* Argument to xInit() and xShutdown() */ +}; + +/* +** CAPI3REF: Configuration Options +** KEYWORDS: {configuration option} +** +** These constants are the available integer configuration options that +** can be passed as the first argument to the [sqlite3_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_config()] to make sure that +** the call worked. The [sqlite3_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Single-thread. In other words, it disables +** all mutexing and puts SQLite into a mode where it can only be used +** by a single thread. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to change the [threading mode] from its default +** value of Single-thread and so [sqlite3_config()] will return +** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD +** configuration option.</dd> +** +** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Multi-thread. In other words, it disables +** mutexing on [database connection] and [prepared statement] objects. +** The application is responsible for serializing access to +** [database connections] and [prepared statements]. But other mutexes +** are enabled so that SQLite will be safe to use in a multi-threaded +** environment as long as no two threads attempt to use the same +** [database connection] at the same time. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to set the Multi-thread [threading mode] and +** [sqlite3_config()] will return [SQLITE_ERROR] if called with the +** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> +** +** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> +** <dd>There are no arguments to this option. ^This option sets the +** [threading mode] to Serialized. In other words, this option enables +** all mutexes including the recursive +** mutexes on [database connection] and [prepared statement] objects. +** In this mode (which is the default when SQLite is compiled with +** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access +** to [database connections] and [prepared statements] so that the +** application is free to use the same [database connection] or the +** same [prepared statement] in different threads at the same time. +** ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** it is not possible to set the Serialized [threading mode] and +** [sqlite3_config()] will return [SQLITE_ERROR] if called with the +** SQLITE_CONFIG_SERIALIZED configuration option.</dd> +** +** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> +** <dd> ^(This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mem_methods] structure. The argument specifies +** alternative low-level memory allocation routines to be used in place of +** the memory allocation routines built into SQLite.)^ ^SQLite makes +** its own private copy of the content of the [sqlite3_mem_methods] structure +** before the [sqlite3_config()] call returns.</dd> +** +** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> +** <dd> ^(This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] +** structure is filled with the currently defined memory allocation routines.)^ +** This option can be used to overload the default memory allocation +** routines with a wrapper that simulations memory allocation failure or +** tracks memory usage, for example. </dd> +** +** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> +** <dd> ^This option takes single argument of type int, interpreted as a +** boolean, which enables or disables the collection of memory allocation +** statistics. ^(When memory allocation statistics are disabled, the +** following SQLite interfaces become non-operational: +** <ul> +** <li> [sqlite3_memory_used()] +** <li> [sqlite3_memory_highwater()] +** <li> [sqlite3_soft_heap_limit64()] +** <li> [sqlite3_status()] +** </ul>)^ +** ^Memory allocation statistics are enabled by default unless SQLite is +** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory +** allocation statistics are disabled by default. +** </dd> +** +** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> +** <dd> ^This option specifies a static memory buffer that SQLite can use for +** scratch memory. There are three arguments: A pointer an 8-byte +** aligned memory buffer from which the scratch allocations will be +** drawn, the size of each scratch allocation (sz), +** and the maximum number of scratch allocations (N). The sz +** argument must be a multiple of 16. +** The first argument must be a pointer to an 8-byte aligned buffer +** of at least sz*N bytes of memory. +** ^SQLite will use no more than two scratch buffers per thread. So +** N should be set to twice the expected maximum number of threads. +** ^SQLite will never require a scratch buffer that is more than 6 +** times the database page size. ^If SQLite needs needs additional +** scratch memory beyond what is provided by this configuration option, then +** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> +** +** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> +** <dd> ^This option specifies a static memory buffer that SQLite can use for +** the database page cache with the default page cache implementation. +** This configuration should not be used if an application-define page +** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. +** There are three arguments to this option: A pointer to 8-byte aligned +** memory, the size of each page buffer (sz), and the number of pages (N). +** The sz argument should be the size of the largest database page +** (a power of two between 512 and 32768) plus a little extra for each +** page header. ^The page header size is 20 to 40 bytes depending on +** the host architecture. ^It is harmless, apart from the wasted memory, +** to make sz a little too large. The first +** argument should point to an allocation of at least sz*N bytes of memory. +** ^SQLite will use the memory provided by the first argument to satisfy its +** memory needs for the first N pages that it adds to cache. ^If additional +** page cache memory is needed beyond what is provided by this option, then +** SQLite goes to [sqlite3_malloc()] for the additional storage space. +** The pointer in the first argument must +** be aligned to an 8-byte boundary or subsequent behavior of SQLite +** will be undefined.</dd> +** +** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> +** <dd> ^This option specifies a static memory buffer that SQLite will use +** for all of its dynamic memory allocation needs beyond those provided +** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. +** There are three arguments: An 8-byte aligned pointer to the memory, +** the number of bytes in the memory buffer, and the minimum allocation size. +** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts +** to using its default memory allocator (the system malloc() implementation), +** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the +** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or +** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory +** allocator is engaged to handle all of SQLites memory allocation needs. +** The first pointer (the memory pointer) must be aligned to an 8-byte +** boundary or subsequent behavior of SQLite will be undefined. +** The minimum allocation size is capped at 2**12. Reasonable values +** for the minimum allocation size are 2**5 through 2**8.</dd> +** +** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> +** <dd> ^(This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mutex_methods] structure. The argument specifies +** alternative low-level mutex routines to be used in place +** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the +** content of the [sqlite3_mutex_methods] structure before the call to +** [sqlite3_config()] returns. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** the entire mutexing subsystem is omitted from the build and hence calls to +** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will +** return [SQLITE_ERROR].</dd> +** +** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> +** <dd> ^(This option takes a single argument which is a pointer to an +** instance of the [sqlite3_mutex_methods] structure. The +** [sqlite3_mutex_methods] +** structure is filled with the currently defined mutex routines.)^ +** This option can be used to overload the default mutex allocation +** routines with a wrapper used to track mutex usage for performance +** profiling or testing, for example. ^If SQLite is compiled with +** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then +** the entire mutexing subsystem is omitted from the build and hence calls to +** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will +** return [SQLITE_ERROR].</dd> +** +** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> +** <dd> ^(This option takes two arguments that determine the default +** memory allocation for the lookaside memory allocator on each +** [database connection]. The first argument is the +** size of each lookaside buffer slot and the second is the number of +** slots allocated to each database connection.)^ ^(This option sets the +** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] +** verb to [sqlite3_db_config()] can be used to change the lookaside +** configuration on individual connections.)^ </dd> +** +** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt> +** <dd> ^(This option takes a single argument which is a pointer to +** an [sqlite3_pcache_methods] object. This object specifies the interface +** to a custom page cache implementation.)^ ^SQLite makes a copy of the +** object and uses it for page cache memory allocations.</dd> +** +** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt> +** <dd> ^(This option takes a single argument which is a pointer to an +** [sqlite3_pcache_methods] object. SQLite copies of the current +** page cache implementation into that object.)^ </dd> +** +** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> +** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a +** function with a call signature of void(*)(void*,int,const char*), +** and a pointer to void. ^If the function pointer is not NULL, it is +** invoked by [sqlite3_log()] to process each logging event. ^If the +** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. +** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is +** passed through as the first parameter to the application-defined logger +** function whenever that function is invoked. ^The second parameter to +** the logger function is a copy of the first parameter to the corresponding +** [sqlite3_log()] call and is intended to be a [result code] or an +** [extended result code]. ^The third parameter passed to the logger is +** log message after formatting via [sqlite3_snprintf()]. +** The SQLite logging interface is not reentrant; the logger function +** supplied by the application must not invoke any SQLite interface. +** In a multi-threaded application, the application-defined logger +** function must be threadsafe. </dd> +** +** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI +** <dd> This option takes a single argument of type int. If non-zero, then +** URI handling is globally enabled. If the parameter is zero, then URI handling +** is globally disabled. If URI handling is globally enabled, all filenames +** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or +** specified as part of [ATTACH] commands are interpreted as URIs, regardless +** of whether or not the [SQLITE_OPEN_URI] flag is set when the database +** connection is opened. If it is globally disabled, filenames are +** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the +** database connection is opened. By default, URI handling is globally +** disabled. The default value may be changed by compiling with the +** [SQLITE_USE_URI] symbol defined. +** </dl> +*/ +#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ +#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ +#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ +#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ +#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ +#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ +#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ +#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ +#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ +#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ +/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ +#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ +#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ +#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ +#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ +#define SQLITE_CONFIG_URI 17 /* int */ + +/* +** CAPI3REF: Database Connection Configuration Options +** +** These constants are the available integer configuration options that +** can be passed as the second argument to the [sqlite3_db_config()] interface. +** +** New configuration options may be added in future releases of SQLite. +** Existing configuration options might be discontinued. Applications +** should check the return code from [sqlite3_db_config()] to make sure that +** the call worked. ^The [sqlite3_db_config()] interface will return a +** non-zero [error code] if a discontinued or unsupported configuration option +** is invoked. +** +** <dl> +** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> +** <dd> ^This option takes three additional arguments that determine the +** [lookaside memory allocator] configuration for the [database connection]. +** ^The first argument (the third parameter to [sqlite3_db_config()] is a +** pointer to a memory buffer to use for lookaside memory. +** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb +** may be NULL in which case SQLite will allocate the +** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the +** size of each lookaside buffer slot. ^The third argument is the number of +** slots. The size of the buffer in the first argument must be greater than +** or equal to the product of the second and third arguments. The buffer +** must be aligned to an 8-byte boundary. ^If the second argument to +** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally +** rounded down to the next smaller multiple of 8. ^(The lookaside memory +** configuration for a database connection can only be changed when that +** connection is not currently using lookaside memory, or in other words +** when the "current value" returned by +** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. +** Any attempt to change the lookaside memory configuration when lookaside +** memory is in use leaves the configuration unchanged and returns +** [SQLITE_BUSY].)^</dd> +** +** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> +** <dd> ^This option is used to enable or disable the enforcement of +** [foreign key constraints]. There should be two additional arguments. +** The first argument is an integer which is 0 to disable FK enforcement, +** positive to enable FK enforcement or negative to leave FK enforcement +** unchanged. The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether FK enforcement is off or on +** following this call. The second parameter may be a NULL pointer, in +** which case the FK enforcement setting is not reported back. </dd> +** +** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> +** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. +** There should be two additional arguments. +** The first argument is an integer which is 0 to disable triggers, +** positive to enable triggers or negative to leave the setting unchanged. +** The second parameter is a pointer to an integer into which +** is written 0 or 1 to indicate whether triggers are disabled or enabled +** following this call. The second parameter may be a NULL pointer, in +** which case the trigger setting is not reported back. </dd> +** +** </dl> +*/ +#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ +#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ +#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ + + +/* +** CAPI3REF: Enable Or Disable Extended Result Codes +** +** ^The sqlite3_extended_result_codes() routine enables or disables the +** [extended result codes] feature of SQLite. ^The extended result +** codes are disabled by default for historical compatibility. +*/ +int sqlite3_extended_result_codes(sqlite3*, int onoff); + +/* +** CAPI3REF: Last Insert Rowid +** +** ^Each entry in an SQLite table has a unique 64-bit signed +** integer key called the [ROWID | "rowid"]. ^The rowid is always available +** as an undeclared column named ROWID, OID, or _ROWID_ as long as those +** names are not also used by explicitly declared columns. ^If +** the table has a column of type [INTEGER PRIMARY KEY] then that column +** is another alias for the rowid. +** +** ^This routine returns the [rowid] of the most recent +** successful [INSERT] into the database from the [database connection] +** in the first argument. ^As of SQLite version 3.7.7, this routines +** records the last insert rowid of both ordinary tables and [virtual tables]. +** ^If no successful [INSERT]s +** have ever occurred on that database connection, zero is returned. +** +** ^(If an [INSERT] occurs within a trigger or within a [virtual table] +** method, then this routine will return the [rowid] of the inserted +** row as long as the trigger or virtual table method is running. +** But once the trigger or virtual table method ends, the value returned +** by this routine reverts to what it was before the trigger or virtual +** table method began.)^ +** +** ^An [INSERT] that fails due to a constraint violation is not a +** successful [INSERT] and does not change the value returned by this +** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, +** and INSERT OR ABORT make no changes to the return value of this +** routine when their insertion fails. ^(When INSERT OR REPLACE +** encounters a constraint violation, it does not fail. The +** INSERT continues to completion after deleting rows that caused +** the constraint problem so INSERT OR REPLACE will always change +** the return value of this interface.)^ +** +** ^For the purposes of this routine, an [INSERT] is considered to +** be successful even if it is subsequently rolled back. +** +** This function is accessible to SQL statements via the +** [last_insert_rowid() SQL function]. +** +** If a separate thread performs a new [INSERT] on the same +** database connection while the [sqlite3_last_insert_rowid()] +** function is running and thus changes the last insert [rowid], +** then the value returned by [sqlite3_last_insert_rowid()] is +** unpredictable and might not equal either the old or the new +** last insert [rowid]. +*/ +sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); + +/* +** CAPI3REF: Count The Number Of Rows Modified +** +** ^This function returns the number of database rows that were changed +** or inserted or deleted by the most recently completed SQL statement +** on the [database connection] specified by the first parameter. +** ^(Only changes that are directly specified by the [INSERT], [UPDATE], +** or [DELETE] statement are counted. Auxiliary changes caused by +** triggers or [foreign key actions] are not counted.)^ Use the +** [sqlite3_total_changes()] function to find the total number of changes +** including changes caused by triggers and foreign key actions. +** +** ^Changes to a view that are simulated by an [INSTEAD OF trigger] +** are not counted. Only real table changes are counted. +** +** ^(A "row change" is a change to a single row of a single table +** caused by an INSERT, DELETE, or UPDATE statement. Rows that +** are changed as side effects of [REPLACE] constraint resolution, +** rollback, ABORT processing, [DROP TABLE], or by any other +** mechanisms do not count as direct row changes.)^ +** +** A "trigger context" is a scope of execution that begins and +** ends with the script of a [CREATE TRIGGER | trigger]. +** Most SQL statements are +** evaluated outside of any trigger. This is the "top level" +** trigger context. If a trigger fires from the top level, a +** new trigger context is entered for the duration of that one +** trigger. Subtriggers create subcontexts for their duration. +** +** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does +** not create a new trigger context. +** +** ^This function returns the number of direct row changes in the +** most recent INSERT, UPDATE, or DELETE statement within the same +** trigger context. +** +** ^Thus, when called from the top level, this function returns the +** number of changes in the most recent INSERT, UPDATE, or DELETE +** that also occurred at the top level. ^(Within the body of a trigger, +** the sqlite3_changes() interface can be called to find the number of +** changes in the most recently completed INSERT, UPDATE, or DELETE +** statement within the body of the same trigger. +** However, the number returned does not include changes +** caused by subtriggers since those have their own context.)^ +** +** See also the [sqlite3_total_changes()] interface, the +** [count_changes pragma], and the [changes() SQL function]. +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_changes()] is running then the value returned +** is unpredictable and not meaningful. +*/ +int sqlite3_changes(sqlite3*); + +/* +** CAPI3REF: Total Number Of Rows Modified +** +** ^This function returns the number of row changes caused by [INSERT], +** [UPDATE] or [DELETE] statements since the [database connection] was opened. +** ^(The count returned by sqlite3_total_changes() includes all changes +** from all [CREATE TRIGGER | trigger] contexts and changes made by +** [foreign key actions]. However, +** the count does not include changes used to implement [REPLACE] constraints, +** do rollbacks or ABORT processing, or [DROP TABLE] processing. The +** count does not include rows of views that fire an [INSTEAD OF trigger], +** though if the INSTEAD OF trigger makes changes of its own, those changes +** are counted.)^ +** ^The sqlite3_total_changes() function counts the changes as soon as +** the statement that makes them is completed (when the statement handle +** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). +** +** See also the [sqlite3_changes()] interface, the +** [count_changes pragma], and the [total_changes() SQL function]. +** +** If a separate thread makes changes on the same database connection +** while [sqlite3_total_changes()] is running then the value +** returned is unpredictable and not meaningful. +*/ +int sqlite3_total_changes(sqlite3*); + +/* +** CAPI3REF: Interrupt A Long-Running Query +** +** ^This function causes any pending database operation to abort and +** return at its earliest opportunity. This routine is typically +** called in response to a user action such as pressing "Cancel" +** or Ctrl-C where the user wants a long query operation to halt +** immediately. +** +** ^It is safe to call this routine from a thread different from the +** thread that is currently running the database operation. But it +** is not safe to call this routine with a [database connection] that +** is closed or might close before sqlite3_interrupt() returns. +** +** ^If an SQL operation is very nearly finished at the time when +** sqlite3_interrupt() is called, then it might not have an opportunity +** to be interrupted and might continue to completion. +** +** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. +** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE +** that is inside an explicit transaction, then the entire transaction +** will be rolled back automatically. +** +** ^The sqlite3_interrupt(D) call is in effect until all currently running +** SQL statements on [database connection] D complete. ^Any new SQL statements +** that are started after the sqlite3_interrupt() call and before the +** running statements reaches zero are interrupted as if they had been +** running prior to the sqlite3_interrupt() call. ^New SQL statements +** that are started after the running statement count reaches zero are +** not effected by the sqlite3_interrupt(). +** ^A call to sqlite3_interrupt(D) that occurs when there are no running +** SQL statements is a no-op and has no effect on SQL statements +** that are started after the sqlite3_interrupt() call returns. +** +** If the database connection closes while [sqlite3_interrupt()] +** is running then bad things will likely happen. +*/ +void sqlite3_interrupt(sqlite3*); + +/* +** CAPI3REF: Determine If An SQL Statement Is Complete +** +** These routines are useful during command-line input to determine if the +** currently entered text seems to form a complete SQL statement or +** if additional input is needed before sending the text into +** SQLite for parsing. ^These routines return 1 if the input string +** appears to be a complete SQL statement. ^A statement is judged to be +** complete if it ends with a semicolon token and is not a prefix of a +** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within +** string literals or quoted identifier names or comments are not +** independent tokens (they are part of the token in which they are +** embedded) and thus do not count as a statement terminator. ^Whitespace +** and comments that follow the final semicolon are ignored. +** +** ^These routines return 0 if the statement is incomplete. ^If a +** memory allocation fails, then SQLITE_NOMEM is returned. +** +** ^These routines do not parse the SQL statements thus +** will not detect syntactically incorrect SQL. +** +** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior +** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked +** automatically by sqlite3_complete16(). If that initialization fails, +** then the return value from sqlite3_complete16() will be non-zero +** regardless of whether or not the input SQL is complete.)^ +** +** The input to [sqlite3_complete()] must be a zero-terminated +** UTF-8 string. +** +** The input to [sqlite3_complete16()] must be a zero-terminated +** UTF-16 string in native byte order. +*/ +int sqlite3_complete(const char *sql); +int sqlite3_complete16(const void *sql); + +/* +** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors +** +** ^This routine sets a callback function that might be invoked whenever +** an attempt is made to open a database table that another thread +** or process has locked. +** +** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] +** is returned immediately upon encountering the lock. ^If the busy callback +** is not NULL, then the callback might be invoked with two arguments. +** +** ^The first argument to the busy handler is a copy of the void* pointer which +** is the third argument to sqlite3_busy_handler(). ^The second argument to +** the busy handler callback is the number of times that the busy handler has +** been invoked for this locking event. ^If the +** busy callback returns 0, then no additional attempts are made to +** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. +** ^If the callback returns non-zero, then another attempt +** is made to open the database for reading and the cycle repeats. +** +** The presence of a busy handler does not guarantee that it will be invoked +** when there is lock contention. ^If SQLite determines that invoking the busy +** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] +** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. +** Consider a scenario where one process is holding a read lock that +** it is trying to promote to a reserved lock and +** a second process is holding a reserved lock that it is trying +** to promote to an exclusive lock. The first process cannot proceed +** because it is blocked by the second and the second process cannot +** proceed because it is blocked by the first. If both processes +** invoke the busy handlers, neither will make any progress. Therefore, +** SQLite returns [SQLITE_BUSY] for the first process, hoping that this +** will induce the first process to release its read lock and allow +** the second process to proceed. +** +** ^The default busy callback is NULL. +** +** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] +** when SQLite is in the middle of a large transaction where all the +** changes will not fit into the in-memory cache. SQLite will +** already hold a RESERVED lock on the database file, but it needs +** to promote this lock to EXCLUSIVE so that it can spill cache +** pages into the database file without harm to concurrent +** readers. ^If it is unable to promote the lock, then the in-memory +** cache will be left in an inconsistent state and so the error +** code is promoted from the relatively benign [SQLITE_BUSY] to +** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion +** forces an automatic rollback of the changes. See the +** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> +** CorruptionFollowingBusyError</a> wiki page for a discussion of why +** this is important. +** +** ^(There can only be a single busy handler defined for each +** [database connection]. Setting a new busy handler clears any +** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] +** will also set or clear the busy handler. +** +** The busy callback should not take any actions which modify the +** database connection that invoked the busy handler. Any such actions +** result in undefined behavior. +** +** A busy handler must not close the database connection +** or [prepared statement] that invoked the busy handler. +*/ +int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); + +/* +** CAPI3REF: Set A Busy Timeout +** +** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps +** for a specified amount of time when a table is locked. ^The handler +** will sleep multiple times until at least "ms" milliseconds of sleeping +** have accumulated. ^After at least "ms" milliseconds of sleeping, +** the handler returns 0 which causes [sqlite3_step()] to return +** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. +** +** ^Calling this routine with an argument less than or equal to zero +** turns off all busy handlers. +** +** ^(There can only be a single busy handler for a particular +** [database connection] any any given moment. If another busy handler +** was defined (using [sqlite3_busy_handler()]) prior to calling +** this routine, that other busy handler is cleared.)^ +*/ +int sqlite3_busy_timeout(sqlite3*, int ms); + +/* +** CAPI3REF: Convenience Routines For Running Queries +** +** This is a legacy interface that is preserved for backwards compatibility. +** Use of this interface is not recommended. +** +** Definition: A <b>result table</b> is memory data structure created by the +** [sqlite3_get_table()] interface. A result table records the +** complete query results from one or more queries. +** +** The table conceptually has a number of rows and columns. But +** these numbers are not part of the result table itself. These +** numbers are obtained separately. Let N be the number of rows +** and M be the number of columns. +** +** A result table is an array of pointers to zero-terminated UTF-8 strings. +** There are (N+1)*M elements in the array. The first M pointers point +** to zero-terminated strings that contain the names of the columns. +** The remaining entries all point to query results. NULL values result +** in NULL pointers. All other values are in their UTF-8 zero-terminated +** string representation as returned by [sqlite3_column_text()]. +** +** A result table might consist of one or more memory allocations. +** It is not safe to pass a result table directly to [sqlite3_free()]. +** A result table should be deallocated using [sqlite3_free_table()]. +** +** ^(As an example of the result table format, suppose a query result +** is as follows: +** +** <blockquote><pre> +** Name | Age +** ----------------------- +** Alice | 43 +** Bob | 28 +** Cindy | 21 +** </pre></blockquote> +** +** There are two column (M==2) and three rows (N==3). Thus the +** result table has 8 entries. Suppose the result table is stored +** in an array names azResult. Then azResult holds this content: +** +** <blockquote><pre> +** azResult[0] = "Name"; +** azResult[1] = "Age"; +** azResult[2] = "Alice"; +** azResult[3] = "43"; +** azResult[4] = "Bob"; +** azResult[5] = "28"; +** azResult[6] = "Cindy"; +** azResult[7] = "21"; +** </pre></blockquote>)^ +** +** ^The sqlite3_get_table() function evaluates one or more +** semicolon-separated SQL statements in the zero-terminated UTF-8 +** string of its 2nd parameter and returns a result table to the +** pointer given in its 3rd parameter. +** +** After the application has finished with the result from sqlite3_get_table(), +** it must pass the result table pointer to sqlite3_free_table() in order to +** release the memory that was malloced. Because of the way the +** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling +** function must not try to call [sqlite3_free()] directly. Only +** [sqlite3_free_table()] is able to release the memory properly and safely. +** +** The sqlite3_get_table() interface is implemented as a wrapper around +** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access +** to any internal data structures of SQLite. It uses only the public +** interface defined here. As a consequence, errors that occur in the +** wrapper layer outside of the internal [sqlite3_exec()] call are not +** reflected in subsequent calls to [sqlite3_errcode()] or +** [sqlite3_errmsg()]. +*/ +int sqlite3_get_table( + sqlite3 *db, /* An open database */ + const char *zSql, /* SQL to be evaluated */ + char ***pazResult, /* Results of the query */ + int *pnRow, /* Number of result rows written here */ + int *pnColumn, /* Number of result columns written here */ + char **pzErrmsg /* Error msg written here */ +); +void sqlite3_free_table(char **result); + +/* +** CAPI3REF: Formatted String Printing Functions +** +** These routines are work-alikes of the "printf()" family of functions +** from the standard C library. +** +** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their +** results into memory obtained from [sqlite3_malloc()]. +** The strings returned by these two routines should be +** released by [sqlite3_free()]. ^Both routines return a +** NULL pointer if [sqlite3_malloc()] is unable to allocate enough +** memory to hold the resulting string. +** +** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from +** the standard C library. The result is written into the +** buffer supplied as the second parameter whose size is given by +** the first parameter. Note that the order of the +** first two parameters is reversed from snprintf().)^ This is an +** historical accident that cannot be fixed without breaking +** backwards compatibility. ^(Note also that sqlite3_snprintf() +** returns a pointer to its buffer instead of the number of +** characters actually written into the buffer.)^ We admit that +** the number of characters written would be a more useful return +** value but we cannot change the implementation of sqlite3_snprintf() +** now without breaking compatibility. +** +** ^As long as the buffer size is greater than zero, sqlite3_snprintf() +** guarantees that the buffer is always zero-terminated. ^The first +** parameter "n" is the total size of the buffer, including space for +** the zero terminator. So the longest string that can be completely +** written will be n-1 characters. +** +** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). +** +** These routines all implement some additional formatting +** options that are useful for constructing SQL statements. +** All of the usual printf() formatting options apply. In addition, there +** is are "%q", "%Q", and "%z" options. +** +** ^(The %q option works like %s in that it substitutes a null-terminated +** string from the argument list. But %q also doubles every '\'' character. +** %q is designed for use inside a string literal.)^ By doubling each '\'' +** character it escapes that character and allows it to be inserted into +** the string. +** +** For example, assume the string variable zText contains text as follows: +** +** <blockquote><pre> +** char *zText = "It's a happy day!"; +** </pre></blockquote> +** +** One can use this text in an SQL statement as follows: +** +** <blockquote><pre> +** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); +** sqlite3_exec(db, zSQL, 0, 0, 0); +** sqlite3_free(zSQL); +** </pre></blockquote> +** +** Because the %q format string is used, the '\'' character in zText +** is escaped and the SQL generated is as follows: +** +** <blockquote><pre> +** INSERT INTO table1 VALUES('It''s a happy day!') +** </pre></blockquote> +** +** This is correct. Had we used %s instead of %q, the generated SQL +** would have looked like this: +** +** <blockquote><pre> +** INSERT INTO table1 VALUES('It's a happy day!'); +** </pre></blockquote> +** +** This second example is an SQL syntax error. As a general rule you should +** always use %q instead of %s when inserting text into a string literal. +** +** ^(The %Q option works like %q except it also adds single quotes around +** the outside of the total string. Additionally, if the parameter in the +** argument list is a NULL pointer, %Q substitutes the text "NULL" (without +** single quotes).)^ So, for example, one could say: +** +** <blockquote><pre> +** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); +** sqlite3_exec(db, zSQL, 0, 0, 0); +** sqlite3_free(zSQL); +** </pre></blockquote> +** +** The code above will render a correct SQL statement in the zSQL +** variable even if the zText variable is a NULL pointer. +** +** ^(The "%z" formatting option works like "%s" but with the +** addition that after the string has been read and copied into +** the result, [sqlite3_free()] is called on the input string.)^ +*/ +char *sqlite3_mprintf(const char*,...); +char *sqlite3_vmprintf(const char*, va_list); +char *sqlite3_snprintf(int,char*,const char*, ...); +char *sqlite3_vsnprintf(int,char*,const char*, va_list); + +/* +** CAPI3REF: Memory Allocation Subsystem +** +** The SQLite core uses these three routines for all of its own +** internal memory allocation needs. "Core" in the previous sentence +** does not include operating-system specific VFS implementation. The +** Windows VFS uses native malloc() and free() for some operations. +** +** ^The sqlite3_malloc() routine returns a pointer to a block +** of memory at least N bytes in length, where N is the parameter. +** ^If sqlite3_malloc() is unable to obtain sufficient free +** memory, it returns a NULL pointer. ^If the parameter N to +** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns +** a NULL pointer. +** +** ^Calling sqlite3_free() with a pointer previously returned +** by sqlite3_malloc() or sqlite3_realloc() releases that memory so +** that it might be reused. ^The sqlite3_free() routine is +** a no-op if is called with a NULL pointer. Passing a NULL pointer +** to sqlite3_free() is harmless. After being freed, memory +** should neither be read nor written. Even reading previously freed +** memory might result in a segmentation fault or other severe error. +** Memory corruption, a segmentation fault, or other severe error +** might result if sqlite3_free() is called with a non-NULL pointer that +** was not obtained from sqlite3_malloc() or sqlite3_realloc(). +** +** ^(The sqlite3_realloc() interface attempts to resize a +** prior memory allocation to be at least N bytes, where N is the +** second parameter. The memory allocation to be resized is the first +** parameter.)^ ^ If the first parameter to sqlite3_realloc() +** is a NULL pointer then its behavior is identical to calling +** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). +** ^If the second parameter to sqlite3_realloc() is zero or +** negative then the behavior is exactly the same as calling +** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). +** ^sqlite3_realloc() returns a pointer to a memory allocation +** of at least N bytes in size or NULL if sufficient memory is unavailable. +** ^If M is the size of the prior allocation, then min(N,M) bytes +** of the prior allocation are copied into the beginning of buffer returned +** by sqlite3_realloc() and the prior allocation is freed. +** ^If sqlite3_realloc() returns NULL, then the prior allocation +** is not freed. +** +** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() +** is always aligned to at least an 8 byte boundary, or to a +** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time +** option is used. +** +** In SQLite version 3.5.0 and 3.5.1, it was possible to define +** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in +** implementation of these routines to be omitted. That capability +** is no longer provided. Only built-in memory allocators can be used. +** +** The Windows OS interface layer calls +** the system malloc() and free() directly when converting +** filenames between the UTF-8 encoding used by SQLite +** and whatever filename encoding is used by the particular Windows +** installation. Memory allocation errors are detected, but +** they are reported back as [SQLITE_CANTOPEN] or +** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. +** +** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] +** must be either NULL or else pointers obtained from a prior +** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have +** not yet been released. +** +** The application must not read or write any part of +** a block of memory after it has been released using +** [sqlite3_free()] or [sqlite3_realloc()]. +*/ +void *sqlite3_malloc(int); +void *sqlite3_realloc(void*, int); +void sqlite3_free(void*); + +/* +** CAPI3REF: Memory Allocator Statistics +** +** SQLite provides these two interfaces for reporting on the status +** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] +** routines, which form the built-in memory allocation subsystem. +** +** ^The [sqlite3_memory_used()] routine returns the number of bytes +** of memory currently outstanding (malloced but not freed). +** ^The [sqlite3_memory_highwater()] routine returns the maximum +** value of [sqlite3_memory_used()] since the high-water mark +** was last reset. ^The values returned by [sqlite3_memory_used()] and +** [sqlite3_memory_highwater()] include any overhead +** added by SQLite in its implementation of [sqlite3_malloc()], +** but not overhead added by the any underlying system library +** routines that [sqlite3_malloc()] may call. +** +** ^The memory high-water mark is reset to the current value of +** [sqlite3_memory_used()] if and only if the parameter to +** [sqlite3_memory_highwater()] is true. ^The value returned +** by [sqlite3_memory_highwater(1)] is the high-water mark +** prior to the reset. +*/ +sqlite3_int64 sqlite3_memory_used(void); +sqlite3_int64 sqlite3_memory_highwater(int resetFlag); + +/* +** CAPI3REF: Pseudo-Random Number Generator +** +** SQLite contains a high-quality pseudo-random number generator (PRNG) used to +** select random [ROWID | ROWIDs] when inserting new records into a table that +** already uses the largest possible [ROWID]. The PRNG is also used for +** the build-in random() and randomblob() SQL functions. This interface allows +** applications to access the same PRNG for other purposes. +** +** ^A call to this routine stores N bytes of randomness into buffer P. +** +** ^The first time this routine is invoked (either internally or by +** the application) the PRNG is seeded using randomness obtained +** from the xRandomness method of the default [sqlite3_vfs] object. +** ^On all subsequent invocations, the pseudo-randomness is generated +** internally and without recourse to the [sqlite3_vfs] xRandomness +** method. +*/ +void sqlite3_randomness(int N, void *P); + +/* +** CAPI3REF: Compile-Time Authorization Callbacks +** +** ^This routine registers an authorizer callback with a particular +** [database connection], supplied in the first argument. +** ^The authorizer callback is invoked as SQL statements are being compiled +** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], +** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various +** points during the compilation process, as logic is being created +** to perform various actions, the authorizer callback is invoked to +** see if those actions are allowed. ^The authorizer callback should +** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the +** specific action but allow the SQL statement to continue to be +** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be +** rejected with an error. ^If the authorizer callback returns +** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] +** then the [sqlite3_prepare_v2()] or equivalent call that triggered +** the authorizer will fail with an error message. +** +** When the callback returns [SQLITE_OK], that means the operation +** requested is ok. ^When the callback returns [SQLITE_DENY], the +** [sqlite3_prepare_v2()] or equivalent call that triggered the +** authorizer will fail with an error message explaining that +** access is denied. +** +** ^The first parameter to the authorizer callback is a copy of the third +** parameter to the sqlite3_set_authorizer() interface. ^The second parameter +** to the callback is an integer [SQLITE_COPY | action code] that specifies +** the particular action to be authorized. ^The third through sixth parameters +** to the callback are zero-terminated strings that contain additional +** details about the action to be authorized. +** +** ^If the action code is [SQLITE_READ] +** and the callback returns [SQLITE_IGNORE] then the +** [prepared statement] statement is constructed to substitute +** a NULL value in place of the table column that would have +** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] +** return can be used to deny an untrusted user access to individual +** columns of a table. +** ^If the action code is [SQLITE_DELETE] and the callback returns +** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the +** [truncate optimization] is disabled and all rows are deleted individually. +** +** An authorizer is used when [sqlite3_prepare | preparing] +** SQL statements from an untrusted source, to ensure that the SQL statements +** do not try to access data they are not allowed to see, or that they do not +** try to execute malicious statements that damage the database. For +** example, an application may allow a user to enter arbitrary +** SQL queries for evaluation by a database. But the application does +** not want the user to be able to make arbitrary changes to the +** database. An authorizer could then be put in place while the +** user-entered SQL is being [sqlite3_prepare | prepared] that +** disallows everything except [SELECT] statements. +** +** Applications that need to process SQL from untrusted sources +** might also consider lowering resource limits using [sqlite3_limit()] +** and limiting database size using the [max_page_count] [PRAGMA] +** in addition to using an authorizer. +** +** ^(Only a single authorizer can be in place on a database connection +** at a time. Each call to sqlite3_set_authorizer overrides the +** previous call.)^ ^Disable the authorizer by installing a NULL callback. +** The authorizer is disabled by default. +** +** The authorizer callback must not do anything that will modify +** the database connection that invoked the authorizer callback. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the +** statement might be re-prepared during [sqlite3_step()] due to a +** schema change. Hence, the application should ensure that the +** correct authorizer callback remains in place during the [sqlite3_step()]. +** +** ^Note that the authorizer callback is invoked only during +** [sqlite3_prepare()] or its variants. Authorization is not +** performed during statement evaluation in [sqlite3_step()], unless +** as stated in the previous paragraph, sqlite3_step() invokes +** sqlite3_prepare_v2() to reprepare a statement after a schema change. +*/ +int sqlite3_set_authorizer( + sqlite3*, + int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), + void *pUserData +); + +/* +** CAPI3REF: Authorizer Return Codes +** +** The [sqlite3_set_authorizer | authorizer callback function] must +** return either [SQLITE_OK] or one of these two constants in order +** to signal SQLite whether or not the action is permitted. See the +** [sqlite3_set_authorizer | authorizer documentation] for additional +** information. +** +** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] +** from the [sqlite3_vtab_on_conflict()] interface. +*/ +#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ +#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ + +/* +** CAPI3REF: Authorizer Action Codes +** +** The [sqlite3_set_authorizer()] interface registers a callback function +** that is invoked to authorize certain SQL statement actions. The +** second parameter to the callback is an integer code that specifies +** what action is being authorized. These are the integer action codes that +** the authorizer callback may be passed. +** +** These action code values signify what kind of operation is to be +** authorized. The 3rd and 4th parameters to the authorization +** callback function will be parameters or NULL depending on which of these +** codes is used as the second parameter. ^(The 5th parameter to the +** authorizer callback is the name of the database ("main", "temp", +** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback +** is the name of the inner-most trigger or view that is responsible for +** the access attempt or NULL if this access attempt is directly from +** top-level SQL code. +*/ +/******************************************* 3rd ************ 4th ***********/ +#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ +#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ +#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ +#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ +#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ +#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ +#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ +#define SQLITE_DELETE 9 /* Table Name NULL */ +#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ +#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ +#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ +#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ +#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ +#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ +#define SQLITE_DROP_VIEW 17 /* View Name NULL */ +#define SQLITE_INSERT 18 /* Table Name NULL */ +#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ +#define SQLITE_READ 20 /* Table Name Column Name */ +#define SQLITE_SELECT 21 /* NULL NULL */ +#define SQLITE_TRANSACTION 22 /* Operation NULL */ +#define SQLITE_UPDATE 23 /* Table Name Column Name */ +#define SQLITE_ATTACH 24 /* Filename NULL */ +#define SQLITE_DETACH 25 /* Database Name NULL */ +#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ +#define SQLITE_REINDEX 27 /* Index Name NULL */ +#define SQLITE_ANALYZE 28 /* Table Name NULL */ +#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ +#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ +#define SQLITE_FUNCTION 31 /* NULL Function Name */ +#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ +#define SQLITE_COPY 0 /* No longer used */ + +/* +** CAPI3REF: Tracing And Profiling Functions +** +** These routines register callback functions that can be used for +** tracing and profiling the execution of SQL statements. +** +** ^The callback function registered by sqlite3_trace() is invoked at +** various times when an SQL statement is being run by [sqlite3_step()]. +** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the +** SQL statement text as the statement first begins executing. +** ^(Additional sqlite3_trace() callbacks might occur +** as each triggered subprogram is entered. The callbacks for triggers +** contain a UTF-8 SQL comment that identifies the trigger.)^ +** +** ^The callback function registered by sqlite3_profile() is invoked +** as each SQL statement finishes. ^The profile callback contains +** the original statement text and an estimate of wall-clock time +** of how long that statement took to run. ^The profile callback +** time is in units of nanoseconds, however the current implementation +** is only capable of millisecond resolution so the six least significant +** digits in the time are meaningless. Future versions of SQLite +** might provide greater resolution on the profiler callback. The +** sqlite3_profile() function is considered experimental and is +** subject to change in future versions of SQLite. +*/ +void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); +SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, + void(*xProfile)(void*,const char*,sqlite3_uint64), void*); + +/* +** CAPI3REF: Query Progress Callbacks +** +** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback +** function X to be invoked periodically during long running calls to +** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for +** database connection D. An example use for this +** interface is to keep a GUI updated during a large query. +** +** ^The parameter P is passed through as the only parameter to the +** callback function X. ^The parameter N is the number of +** [virtual machine instructions] that are evaluated between successive +** invocations of the callback X. +** +** ^Only a single progress handler may be defined at one time per +** [database connection]; setting a new progress handler cancels the +** old one. ^Setting parameter X to NULL disables the progress handler. +** ^The progress handler is also disabled by setting N to a value less +** than 1. +** +** ^If the progress callback returns non-zero, the operation is +** interrupted. This feature can be used to implement a +** "Cancel" button on a GUI progress dialog box. +** +** The progress handler callback must not do anything that will modify +** the database connection that invoked the progress handler. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +*/ +void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); + +/* +** CAPI3REF: Opening A New Database Connection +** +** ^These routines open an SQLite database file as specified by the +** filename argument. ^The filename argument is interpreted as UTF-8 for +** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte +** order for sqlite3_open16(). ^(A [database connection] handle is usually +** returned in *ppDb, even if an error occurs. The only exception is that +** if SQLite is unable to allocate memory to hold the [sqlite3] object, +** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] +** object.)^ ^(If the database is opened (and/or created) successfully, then +** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The +** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain +** an English language description of the error following a failure of any +** of the sqlite3_open() routines. +** +** ^The default encoding for the database will be UTF-8 if +** sqlite3_open() or sqlite3_open_v2() is called and +** UTF-16 in the native byte order if sqlite3_open16() is used. +** +** Whether or not an error occurs when it is opened, resources +** associated with the [database connection] handle should be released by +** passing it to [sqlite3_close()] when it is no longer required. +** +** The sqlite3_open_v2() interface works like sqlite3_open() +** except that it accepts two additional parameters for additional control +** over the new database connection. ^(The flags parameter to +** sqlite3_open_v2() can take one of +** the following three values, optionally combined with the +** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], +** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ +** +** <dl> +** ^(<dt>[SQLITE_OPEN_READONLY]</dt> +** <dd>The database is opened in read-only mode. If the database does not +** already exist, an error is returned.</dd>)^ +** +** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> +** <dd>The database is opened for reading and writing if possible, or reading +** only if the file is write protected by the operating system. In either +** case the database must already exist, otherwise an error is returned.</dd>)^ +** +** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> +** <dd>The database is opened for reading and writing, and is created if +** it does not already exist. This is the behavior that is always used for +** sqlite3_open() and sqlite3_open16().</dd>)^ +** </dl> +** +** If the 3rd parameter to sqlite3_open_v2() is not one of the +** combinations shown above optionally combined with other +** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] +** then the behavior is undefined. +** +** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection +** opens in the multi-thread [threading mode] as long as the single-thread +** mode has not been set at compile-time or start-time. ^If the +** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens +** in the serialized [threading mode] unless single-thread was +** previously selected at compile-time or start-time. +** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be +** eligible to use [shared cache mode], regardless of whether or not shared +** cache is enabled using [sqlite3_enable_shared_cache()]. ^The +** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not +** participate in [shared cache mode] even if it is enabled. +** +** ^The fourth parameter to sqlite3_open_v2() is the name of the +** [sqlite3_vfs] object that defines the operating system interface that +** the new database connection should use. ^If the fourth parameter is +** a NULL pointer then the default [sqlite3_vfs] object is used. +** +** ^If the filename is ":memory:", then a private, temporary in-memory database +** is created for the connection. ^This in-memory database will vanish when +** the database connection is closed. Future versions of SQLite might +** make use of additional special filenames that begin with the ":" character. +** It is recommended that when a database filename actually does begin with +** a ":" character you should prefix the filename with a pathname such as +** "./" to avoid ambiguity. +** +** ^If the filename is an empty string, then a private, temporary +** on-disk database will be created. ^This private database will be +** automatically deleted as soon as the database connection is closed. +** +** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> +** +** ^If [URI filename] interpretation is enabled, and the filename argument +** begins with "file:", then the filename is interpreted as a URI. ^URI +** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is +** set in the fourth argument to sqlite3_open_v2(), or if it has +** been enabled globally using the [SQLITE_CONFIG_URI] option with the +** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. +** As of SQLite version 3.7.7, URI filename interpretation is turned off +** by default, but future releases of SQLite might enable URI filename +** interpretation by default. See "[URI filenames]" for additional +** information. +** +** URI filenames are parsed according to RFC 3986. ^If the URI contains an +** authority, then it must be either an empty string or the string +** "localhost". ^If the authority is not an empty string or "localhost", an +** error is returned to the caller. ^The fragment component of a URI, if +** present, is ignored. +** +** ^SQLite uses the path component of the URI as the name of the disk file +** which contains the database. ^If the path begins with a '/' character, +** then it is interpreted as an absolute path. ^If the path does not begin +** with a '/' (meaning that the authority section is omitted from the URI) +** then the path is interpreted as a relative path. +** ^On windows, the first component of an absolute path +** is a drive specification (e.g. "C:"). +** +** [[core URI query parameters]] +** The query component of a URI may contain parameters that are interpreted +** either by SQLite itself, or by a [VFS | custom VFS implementation]. +** SQLite interprets the following three query parameters: +** +** <ul> +** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of +** a VFS object that provides the operating system interface that should +** be used to access the database file on disk. ^If this option is set to +** an empty string the default VFS object is used. ^Specifying an unknown +** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is +** present, then the VFS specified by the option takes precedence over +** the value passed as the fourth parameter to sqlite3_open_v2(). +** +** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or +** "rwc". Attempting to set it to any other value is an error)^. +** ^If "ro" is specified, then the database is opened for read-only +** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the +** third argument to sqlite3_prepare_v2(). ^If the mode option is set to +** "rw", then the database is opened for read-write (but not create) +** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had +** been set. ^Value "rwc" is equivalent to setting both +** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is +** used, it is an error to specify a value for the mode parameter that is +** less restrictive than that specified by the flags passed as the third +** parameter. +** +** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or +** "private". ^Setting it to "shared" is equivalent to setting the +** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to +** sqlite3_open_v2(). ^Setting the cache parameter to "private" is +** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. +** ^If sqlite3_open_v2() is used and the "cache" parameter is present in +** a URI filename, its value overrides any behaviour requested by setting +** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. +** </ul> +** +** ^Specifying an unknown parameter in the query component of a URI is not an +** error. Future versions of SQLite might understand additional query +** parameters. See "[query parameters with special meaning to SQLite]" for +** additional information. +** +** [[URI filename examples]] <h3>URI filename examples</h3> +** +** <table border="1" align=center cellpadding=5> +** <tr><th> URI filenames <th> Results +** <tr><td> file:data.db <td> +** Open the file "data.db" in the current directory. +** <tr><td> file:/home/fred/data.db<br> +** file:///home/fred/data.db <br> +** file://localhost/home/fred/data.db <br> <td> +** Open the database file "/home/fred/data.db". +** <tr><td> file://darkstar/home/fred/data.db <td> +** An error. "darkstar" is not a recognized authority. +** <tr><td style="white-space:nowrap"> +** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db +** <td> Windows only: Open the file "data.db" on fred's desktop on drive +** C:. Note that the %20 escaping in this example is not strictly +** necessary - space characters can be used literally +** in URI filenames. +** <tr><td> file:data.db?mode=ro&cache=private <td> +** Open file "data.db" in the current directory for read-only access. +** Regardless of whether or not shared-cache mode is enabled by +** default, use a private cache. +** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> +** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". +** <tr><td> file:data.db?mode=readonly <td> +** An error. "readonly" is not a valid option for the "mode" parameter. +** </table> +** +** ^URI hexadecimal escape sequences (%HH) are supported within the path and +** query components of a URI. A hexadecimal escape sequence consists of a +** percent sign - "%" - followed by exactly two hexadecimal digits +** specifying an octet value. ^Before the path or query components of a +** URI filename are interpreted, they are encoded using UTF-8 and all +** hexadecimal escape sequences replaced by a single byte containing the +** corresponding octet. If this process generates an invalid UTF-8 encoding, +** the results are undefined. +** +** <b>Note to Windows users:</b> The encoding used for the filename argument +** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever +** codepage is currently defined. Filenames containing international +** characters must be converted to UTF-8 prior to passing them into +** sqlite3_open() or sqlite3_open_v2(). +*/ +int sqlite3_open( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +int sqlite3_open16( + const void *filename, /* Database filename (UTF-16) */ + sqlite3 **ppDb /* OUT: SQLite db handle */ +); +int sqlite3_open_v2( + const char *filename, /* Database filename (UTF-8) */ + sqlite3 **ppDb, /* OUT: SQLite db handle */ + int flags, /* Flags */ + const char *zVfs /* Name of VFS module to use */ +); + +/* +** CAPI3REF: Obtain Values For URI Parameters +** +** This is a utility routine, useful to VFS implementations, that checks +** to see if a database file was a URI that contained a specific query +** parameter, and if so obtains the value of the query parameter. +** +** The zFilename argument is the filename pointer passed into the xOpen() +** method of a VFS implementation. The zParam argument is the name of the +** query parameter we seek. This routine returns the value of the zParam +** parameter if it exists. If the parameter does not exist, this routine +** returns a NULL pointer. +** +** If the zFilename argument to this function is not a pointer that SQLite +** passed into the xOpen VFS method, then the behavior of this routine +** is undefined and probably undesirable. +*/ +const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); + + +/* +** CAPI3REF: Error Codes And Messages +** +** ^The sqlite3_errcode() interface returns the numeric [result code] or +** [extended result code] for the most recent failed sqlite3_* API call +** associated with a [database connection]. If a prior API call failed +** but the most recent API call succeeded, the return value from +** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() +** interface is the same except that it always returns the +** [extended result code] even when extended result codes are +** disabled. +** +** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language +** text that describes the error, as either UTF-8 or UTF-16 respectively. +** ^(Memory to hold the error message string is managed internally. +** The application does not need to worry about freeing the result. +** However, the error string might be overwritten or deallocated by +** subsequent calls to other SQLite interface functions.)^ +** +** When the serialized [threading mode] is in use, it might be the +** case that a second error occurs on a separate thread in between +** the time of the first error and the call to these interfaces. +** When that happens, the second error will be reported since these +** interfaces always report the most recent result. To avoid +** this, each thread can obtain exclusive use of the [database connection] D +** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning +** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after +** all calls to the interfaces listed here are completed. +** +** If an interface fails with SQLITE_MISUSE, that means the interface +** was invoked incorrectly by the application. In that case, the +** error code and message may or may not be set. +*/ +int sqlite3_errcode(sqlite3 *db); +int sqlite3_extended_errcode(sqlite3 *db); +const char *sqlite3_errmsg(sqlite3*); +const void *sqlite3_errmsg16(sqlite3*); + +/* +** CAPI3REF: SQL Statement Object +** KEYWORDS: {prepared statement} {prepared statements} +** +** An instance of this object represents a single SQL statement. +** This object is variously known as a "prepared statement" or a +** "compiled SQL statement" or simply as a "statement". +** +** The life of a statement object goes something like this: +** +** <ol> +** <li> Create the object using [sqlite3_prepare_v2()] or a related +** function. +** <li> Bind values to [host parameters] using the sqlite3_bind_*() +** interfaces. +** <li> Run the SQL by calling [sqlite3_step()] one or more times. +** <li> Reset the statement using [sqlite3_reset()] then go back +** to step 2. Do this zero or more times. +** <li> Destroy the object using [sqlite3_finalize()]. +** </ol> +** +** Refer to documentation on individual methods above for additional +** information. +*/ +typedef struct sqlite3_stmt sqlite3_stmt; + +/* +** CAPI3REF: Run-time Limits +** +** ^(This interface allows the size of various constructs to be limited +** on a connection by connection basis. The first parameter is the +** [database connection] whose limit is to be set or queried. The +** second parameter is one of the [limit categories] that define a +** class of constructs to be size limited. The third parameter is the +** new limit for that construct.)^ +** +** ^If the new limit is a negative number, the limit is unchanged. +** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a +** [limits | hard upper bound] +** set at compile-time by a C preprocessor macro called +** [limits | SQLITE_MAX_<i>NAME</i>]. +** (The "_LIMIT_" in the name is changed to "_MAX_".))^ +** ^Attempts to increase a limit above its hard upper bound are +** silently truncated to the hard upper bound. +** +** ^Regardless of whether or not the limit was changed, the +** [sqlite3_limit()] interface returns the prior value of the limit. +** ^Hence, to find the current value of a limit without changing it, +** simply invoke this interface with the third parameter set to -1. +** +** Run-time limits are intended for use in applications that manage +** both their own internal database and also databases that are controlled +** by untrusted external sources. An example application might be a +** web browser that has its own databases for storing history and +** separate databases controlled by JavaScript applications downloaded +** off the Internet. The internal databases can be given the +** large, default limits. Databases managed by external sources can +** be given much smaller limits designed to prevent a denial of service +** attack. Developers might also want to use the [sqlite3_set_authorizer()] +** interface to further control untrusted SQL. The size of the database +** created by an untrusted script can be contained using the +** [max_page_count] [PRAGMA]. +** +** New run-time limit categories may be added in future releases. +*/ +int sqlite3_limit(sqlite3*, int id, int newVal); + +/* +** CAPI3REF: Run-Time Limit Categories +** KEYWORDS: {limit category} {*limit categories} +** +** These constants define various performance limits +** that can be lowered at run-time using [sqlite3_limit()]. +** The synopsis of the meanings of the various limits is shown below. +** Additional information is available at [limits | Limits in SQLite]. +** +** <dl> +** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> +** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ +** +** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> +** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ +** +** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> +** <dd>The maximum number of columns in a table definition or in the +** result set of a [SELECT] or the maximum number of columns in an index +** or in an ORDER BY or GROUP BY clause.</dd>)^ +** +** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> +** <dd>The maximum depth of the parse tree on any expression.</dd>)^ +** +** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> +** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ +** +** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> +** <dd>The maximum number of instructions in a virtual machine program +** used to implement an SQL statement. This limit is not currently +** enforced, though that might be added in some future release of +** SQLite.</dd>)^ +** +** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> +** <dd>The maximum number of arguments on a function.</dd>)^ +** +** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> +** <dd>The maximum number of [ATTACH | attached databases].)^</dd> +** +** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] +** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> +** <dd>The maximum length of the pattern argument to the [LIKE] or +** [GLOB] operators.</dd>)^ +** +** [[SQLITE_LIMIT_VARIABLE_NUMBER]] +** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> +** <dd>The maximum index number of any [parameter] in an SQL statement.)^ +** +** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> +** <dd>The maximum depth of recursion for triggers.</dd>)^ +** </dl> +*/ +#define SQLITE_LIMIT_LENGTH 0 +#define SQLITE_LIMIT_SQL_LENGTH 1 +#define SQLITE_LIMIT_COLUMN 2 +#define SQLITE_LIMIT_EXPR_DEPTH 3 +#define SQLITE_LIMIT_COMPOUND_SELECT 4 +#define SQLITE_LIMIT_VDBE_OP 5 +#define SQLITE_LIMIT_FUNCTION_ARG 6 +#define SQLITE_LIMIT_ATTACHED 7 +#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 +#define SQLITE_LIMIT_VARIABLE_NUMBER 9 +#define SQLITE_LIMIT_TRIGGER_DEPTH 10 + +/* +** CAPI3REF: Compiling An SQL Statement +** KEYWORDS: {SQL statement compiler} +** +** To execute an SQL query, it must first be compiled into a byte-code +** program using one of these routines. +** +** The first argument, "db", is a [database connection] obtained from a +** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or +** [sqlite3_open16()]. The database connection must not have been closed. +** +** The second argument, "zSql", is the statement to be compiled, encoded +** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() +** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() +** use UTF-16. +** +** ^If the nByte argument is less than zero, then zSql is read up to the +** first zero terminator. ^If nByte is non-negative, then it is the maximum +** number of bytes read from zSql. ^When nByte is non-negative, the +** zSql string ends at either the first '\000' or '\u0000' character or +** the nByte-th byte, whichever comes first. If the caller knows +** that the supplied string is nul-terminated, then there is a small +** performance advantage to be gained by passing an nByte parameter that +** is equal to the number of bytes in the input string <i>including</i> +** the nul-terminator bytes as this saves SQLite from having to +** make a copy of the input string. +** +** ^If pzTail is not NULL then *pzTail is made to point to the first byte +** past the end of the first SQL statement in zSql. These routines only +** compile the first statement in zSql, so *pzTail is left pointing to +** what remains uncompiled. +** +** ^*ppStmt is left pointing to a compiled [prepared statement] that can be +** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set +** to NULL. ^If the input text contains no SQL (if the input is an empty +** string or a comment) then *ppStmt is set to NULL. +** The calling procedure is responsible for deleting the compiled +** SQL statement using [sqlite3_finalize()] after it has finished with it. +** ppStmt may not be NULL. +** +** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; +** otherwise an [error code] is returned. +** +** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are +** recommended for all new programs. The two older interfaces are retained +** for backwards compatibility, but their use is discouraged. +** ^In the "v2" interfaces, the prepared statement +** that is returned (the [sqlite3_stmt] object) contains a copy of the +** original SQL text. This causes the [sqlite3_step()] interface to +** behave differently in three ways: +** +** <ol> +** <li> +** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it +** always used to do, [sqlite3_step()] will automatically recompile the SQL +** statement and try to run it again. +** </li> +** +** <li> +** ^When an error occurs, [sqlite3_step()] will return one of the detailed +** [error codes] or [extended error codes]. ^The legacy behavior was that +** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code +** and the application would have to make a second call to [sqlite3_reset()] +** in order to find the underlying cause of the problem. With the "v2" prepare +** interfaces, the underlying reason for the error is returned immediately. +** </li> +** +** <li> +** ^If the specific value bound to [parameter | host parameter] in the +** WHERE clause might influence the choice of query plan for a statement, +** then the statement will be automatically recompiled, as if there had been +** a schema change, on the first [sqlite3_step()] call following any change +** to the [sqlite3_bind_text | bindings] of that [parameter]. +** ^The specific value of WHERE-clause [parameter] might influence the +** choice of query plan if the parameter is the left-hand side of a [LIKE] +** or [GLOB] operator or if the parameter is compared to an indexed column +** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. +** the +** </li> +** </ol> +*/ +int sqlite3_prepare( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare_v2( + sqlite3 *db, /* Database handle */ + const char *zSql, /* SQL statement, UTF-8 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const char **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare16( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); +int sqlite3_prepare16_v2( + sqlite3 *db, /* Database handle */ + const void *zSql, /* SQL statement, UTF-16 encoded */ + int nByte, /* Maximum length of zSql in bytes. */ + sqlite3_stmt **ppStmt, /* OUT: Statement handle */ + const void **pzTail /* OUT: Pointer to unused portion of zSql */ +); + +/* +** CAPI3REF: Retrieving Statement SQL +** +** ^This interface can be used to retrieve a saved copy of the original +** SQL text used to create a [prepared statement] if that statement was +** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. +*/ +const char *sqlite3_sql(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Determine If An SQL Statement Writes The Database +** +** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if +** and only if the [prepared statement] X makes no direct changes to +** the content of the database file. +** +** Note that [application-defined SQL functions] or +** [virtual tables] might change the database indirectly as a side effect. +** ^(For example, if an application defines a function "eval()" that +** calls [sqlite3_exec()], then the following SQL statement would +** change the database file through side-effects: +** +** <blockquote><pre> +** SELECT eval('DELETE FROM t1') FROM t2; +** </pre></blockquote> +** +** But because the [SELECT] statement does not change the database file +** directly, sqlite3_stmt_readonly() would still return true.)^ +** +** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], +** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, +** since the statements themselves do not actually modify the database but +** rather they control the timing of when other statements modify the +** database. ^The [ATTACH] and [DETACH] statements also cause +** sqlite3_stmt_readonly() to return true since, while those statements +** change the configuration of a database connection, they do not make +** changes to the content of the database files on disk. +*/ +int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Dynamically Typed Value Object +** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} +** +** SQLite uses the sqlite3_value object to represent all values +** that can be stored in a database table. SQLite uses dynamic typing +** for the values it stores. ^Values stored in sqlite3_value objects +** can be integers, floating point values, strings, BLOBs, or NULL. +** +** An sqlite3_value object may be either "protected" or "unprotected". +** Some interfaces require a protected sqlite3_value. Other interfaces +** will accept either a protected or an unprotected sqlite3_value. +** Every interface that accepts sqlite3_value arguments specifies +** whether or not it requires a protected sqlite3_value. +** +** The terms "protected" and "unprotected" refer to whether or not +** a mutex is held. An internal mutex is held for a protected +** sqlite3_value object but no mutex is held for an unprotected +** sqlite3_value object. If SQLite is compiled to be single-threaded +** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) +** or if SQLite is run in one of reduced mutex modes +** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] +** then there is no distinction between protected and unprotected +** sqlite3_value objects and they can be used interchangeably. However, +** for maximum code portability it is recommended that applications +** still make the distinction between protected and unprotected +** sqlite3_value objects even when not strictly required. +** +** ^The sqlite3_value objects that are passed as parameters into the +** implementation of [application-defined SQL functions] are protected. +** ^The sqlite3_value object returned by +** [sqlite3_column_value()] is unprotected. +** Unprotected sqlite3_value objects may only be used with +** [sqlite3_result_value()] and [sqlite3_bind_value()]. +** The [sqlite3_value_blob | sqlite3_value_type()] family of +** interfaces require protected sqlite3_value objects. +*/ +typedef struct Mem sqlite3_value; + +/* +** CAPI3REF: SQL Function Context Object +** +** The context in which an SQL function executes is stored in an +** sqlite3_context object. ^A pointer to an sqlite3_context object +** is always first parameter to [application-defined SQL functions]. +** The application-defined SQL function implementation will pass this +** pointer through into calls to [sqlite3_result_int | sqlite3_result()], +** [sqlite3_aggregate_context()], [sqlite3_user_data()], +** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], +** and/or [sqlite3_set_auxdata()]. +*/ +typedef struct sqlite3_context sqlite3_context; + +/* +** CAPI3REF: Binding Values To Prepared Statements +** KEYWORDS: {host parameter} {host parameters} {host parameter name} +** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} +** +** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, +** literals may be replaced by a [parameter] that matches one of following +** templates: +** +** <ul> +** <li> ? +** <li> ?NNN +** <li> :VVV +** <li> @VVV +** <li> $VVV +** </ul> +** +** In the templates above, NNN represents an integer literal, +** and VVV represents an alphanumeric identifier.)^ ^The values of these +** parameters (also called "host parameter names" or "SQL parameters") +** can be set using the sqlite3_bind_*() routines defined here. +** +** ^The first argument to the sqlite3_bind_*() routines is always +** a pointer to the [sqlite3_stmt] object returned from +** [sqlite3_prepare_v2()] or its variants. +** +** ^The second argument is the index of the SQL parameter to be set. +** ^The leftmost SQL parameter has an index of 1. ^When the same named +** SQL parameter is used more than once, second and subsequent +** occurrences have the same index as the first occurrence. +** ^The index for named parameters can be looked up using the +** [sqlite3_bind_parameter_index()] API if desired. ^The index +** for "?NNN" parameters is the value of NNN. +** ^The NNN value must be between 1 and the [sqlite3_limit()] +** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). +** +** ^The third argument is the value to bind to the parameter. +** +** ^(In those routines that have a fourth argument, its value is the +** number of bytes in the parameter. To be clear: the value is the +** number of <u>bytes</u> in the value, not the number of characters.)^ +** ^If the fourth parameter is negative, the length of the string is +** the number of bytes up to the first zero terminator. +** If a non-negative fourth parameter is provided to sqlite3_bind_text() +** or sqlite3_bind_text16() then that parameter must be the byte offset +** where the NUL terminator would occur assuming the string were NUL +** terminated. If any NUL characters occur at byte offsets less than +** the value of the fourth parameter then the resulting string value will +** contain embedded NULs. The result of expressions involving strings +** with embedded NULs is undefined. +** +** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and +** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or +** string after SQLite has finished with it. ^The destructor is called +** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), +** sqlite3_bind_text(), or sqlite3_bind_text16() fails. +** ^If the fifth argument is +** the special value [SQLITE_STATIC], then SQLite assumes that the +** information is in static, unmanaged space and does not need to be freed. +** ^If the fifth argument has the value [SQLITE_TRANSIENT], then +** SQLite makes its own private copy of the data immediately, before +** the sqlite3_bind_*() routine returns. +** +** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that +** is filled with zeroes. ^A zeroblob uses a fixed amount of memory +** (just an integer to hold its size) while it is being processed. +** Zeroblobs are intended to serve as placeholders for BLOBs whose +** content is later written using +** [sqlite3_blob_open | incremental BLOB I/O] routines. +** ^A negative value for the zeroblob results in a zero-length BLOB. +** +** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer +** for the [prepared statement] or with a prepared statement for which +** [sqlite3_step()] has been called more recently than [sqlite3_reset()], +** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() +** routine is passed a [prepared statement] that has been finalized, the +** result is undefined and probably harmful. +** +** ^Bindings are not cleared by the [sqlite3_reset()] routine. +** ^Unbound parameters are interpreted as NULL. +** +** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an +** [error code] if anything goes wrong. +** ^[SQLITE_RANGE] is returned if the parameter +** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. +** +** See also: [sqlite3_bind_parameter_count()], +** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. +*/ +int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); +int sqlite3_bind_double(sqlite3_stmt*, int, double); +int sqlite3_bind_int(sqlite3_stmt*, int, int); +int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); +int sqlite3_bind_null(sqlite3_stmt*, int); +int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); +int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); +int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); +int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); + +/* +** CAPI3REF: Number Of SQL Parameters +** +** ^This routine can be used to find the number of [SQL parameters] +** in a [prepared statement]. SQL parameters are tokens of the +** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as +** placeholders for values that are [sqlite3_bind_blob | bound] +** to the parameters at a later time. +** +** ^(This routine actually returns the index of the largest (rightmost) +** parameter. For all forms except ?NNN, this will correspond to the +** number of unique parameters. If parameters of the ?NNN form are used, +** there may be gaps in the list.)^ +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_name()], and +** [sqlite3_bind_parameter_index()]. +*/ +int sqlite3_bind_parameter_count(sqlite3_stmt*); + +/* +** CAPI3REF: Name Of A Host Parameter +** +** ^The sqlite3_bind_parameter_name(P,N) interface returns +** the name of the N-th [SQL parameter] in the [prepared statement] P. +** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" +** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" +** respectively. +** In other words, the initial ":" or "$" or "@" or "?" +** is included as part of the name.)^ +** ^Parameters of the form "?" without a following integer have no name +** and are referred to as "nameless" or "anonymous parameters". +** +** ^The first host parameter has an index of 1, not 0. +** +** ^If the value N is out of range or if the N-th parameter is +** nameless, then NULL is returned. ^The returned string is +** always in UTF-8 encoding even if the named parameter was +** originally specified as UTF-16 in [sqlite3_prepare16()] or +** [sqlite3_prepare16_v2()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_index()]. +*/ +const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); + +/* +** CAPI3REF: Index Of A Parameter With A Given Name +** +** ^Return the index of an SQL parameter given its name. ^The +** index value returned is suitable for use as the second +** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero +** is returned if no matching parameter is found. ^The parameter +** name must be given in UTF-8 even if the original statement +** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. +** +** See also: [sqlite3_bind_blob|sqlite3_bind()], +** [sqlite3_bind_parameter_count()], and +** [sqlite3_bind_parameter_index()]. +*/ +int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); + +/* +** CAPI3REF: Reset All Bindings On A Prepared Statement +** +** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset +** the [sqlite3_bind_blob | bindings] on a [prepared statement]. +** ^Use this routine to reset all host parameters to NULL. +*/ +int sqlite3_clear_bindings(sqlite3_stmt*); + +/* +** CAPI3REF: Number Of Columns In A Result Set +** +** ^Return the number of columns in the result set returned by the +** [prepared statement]. ^This routine returns 0 if pStmt is an SQL +** statement that does not return data (for example an [UPDATE]). +** +** See also: [sqlite3_data_count()] +*/ +int sqlite3_column_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Column Names In A Result Set +** +** ^These routines return the name assigned to a particular column +** in the result set of a [SELECT] statement. ^The sqlite3_column_name() +** interface returns a pointer to a zero-terminated UTF-8 string +** and sqlite3_column_name16() returns a pointer to a zero-terminated +** UTF-16 string. ^The first parameter is the [prepared statement] +** that implements the [SELECT] statement. ^The second parameter is the +** column number. ^The leftmost column is number 0. +** +** ^The returned string pointer is valid until either the [prepared statement] +** is destroyed by [sqlite3_finalize()] or until the statement is automatically +** reprepared by the first call to [sqlite3_step()] for a particular run +** or until the next call to +** sqlite3_column_name() or sqlite3_column_name16() on the same column. +** +** ^If sqlite3_malloc() fails during the processing of either routine +** (for example during a conversion from UTF-8 to UTF-16) then a +** NULL pointer is returned. +** +** ^The name of a result column is the value of the "AS" clause for +** that column, if there is an AS clause. If there is no AS clause +** then the name of the column is unspecified and may change from +** one release of SQLite to the next. +*/ +const char *sqlite3_column_name(sqlite3_stmt*, int N); +const void *sqlite3_column_name16(sqlite3_stmt*, int N); + +/* +** CAPI3REF: Source Of Data In A Query Result +** +** ^These routines provide a means to determine the database, table, and +** table column that is the origin of a particular result column in +** [SELECT] statement. +** ^The name of the database or table or column can be returned as +** either a UTF-8 or UTF-16 string. ^The _database_ routines return +** the database name, the _table_ routines return the table name, and +** the origin_ routines return the column name. +** ^The returned string is valid until the [prepared statement] is destroyed +** using [sqlite3_finalize()] or until the statement is automatically +** reprepared by the first call to [sqlite3_step()] for a particular run +** or until the same information is requested +** again in a different encoding. +** +** ^The names returned are the original un-aliased names of the +** database, table, and column. +** +** ^The first argument to these interfaces is a [prepared statement]. +** ^These functions return information about the Nth result column returned by +** the statement, where N is the second function argument. +** ^The left-most column is column 0 for these routines. +** +** ^If the Nth column returned by the statement is an expression or +** subquery and is not a column value, then all of these functions return +** NULL. ^These routine might also return NULL if a memory allocation error +** occurs. ^Otherwise, they return the name of the attached database, table, +** or column that query result column was extracted from. +** +** ^As with all other SQLite APIs, those whose names end with "16" return +** UTF-16 encoded strings and the other functions return UTF-8. +** +** ^These APIs are only available if the library was compiled with the +** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. +** +** If two or more threads call one or more of these routines against the same +** prepared statement and column at the same time then the results are +** undefined. +** +** If two or more threads call one or more +** [sqlite3_column_database_name | column metadata interfaces] +** for the same [prepared statement] and result column +** at the same time then the results are undefined. +*/ +const char *sqlite3_column_database_name(sqlite3_stmt*,int); +const void *sqlite3_column_database_name16(sqlite3_stmt*,int); +const char *sqlite3_column_table_name(sqlite3_stmt*,int); +const void *sqlite3_column_table_name16(sqlite3_stmt*,int); +const char *sqlite3_column_origin_name(sqlite3_stmt*,int); +const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Declared Datatype Of A Query Result +** +** ^(The first parameter is a [prepared statement]. +** If this statement is a [SELECT] statement and the Nth column of the +** returned result set of that [SELECT] is a table column (not an +** expression or subquery) then the declared type of the table +** column is returned.)^ ^If the Nth column of the result set is an +** expression or subquery, then a NULL pointer is returned. +** ^The returned string is always UTF-8 encoded. +** +** ^(For example, given the database schema: +** +** CREATE TABLE t1(c1 VARIANT); +** +** and the following statement to be compiled: +** +** SELECT c1 + 1, c1 FROM t1; +** +** this routine would return the string "VARIANT" for the second result +** column (i==1), and a NULL pointer for the first result column (i==0).)^ +** +** ^SQLite uses dynamic run-time typing. ^So just because a column +** is declared to contain a particular type does not mean that the +** data stored in that column is of the declared type. SQLite is +** strongly typed, but the typing is dynamic not static. ^Type +** is associated with individual values, not with the containers +** used to hold those values. +*/ +const char *sqlite3_column_decltype(sqlite3_stmt*,int); +const void *sqlite3_column_decltype16(sqlite3_stmt*,int); + +/* +** CAPI3REF: Evaluate An SQL Statement +** +** After a [prepared statement] has been prepared using either +** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy +** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function +** must be called one or more times to evaluate the statement. +** +** The details of the behavior of the sqlite3_step() interface depend +** on whether the statement was prepared using the newer "v2" interface +** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy +** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the +** new "v2" interface is recommended for new applications but the legacy +** interface will continue to be supported. +** +** ^In the legacy interface, the return value will be either [SQLITE_BUSY], +** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. +** ^With the "v2" interface, any of the other [result codes] or +** [extended result codes] might be returned as well. +** +** ^[SQLITE_BUSY] means that the database engine was unable to acquire the +** database locks it needs to do its job. ^If the statement is a [COMMIT] +** or occurs outside of an explicit transaction, then you can retry the +** statement. If the statement is not a [COMMIT] and occurs within an +** explicit transaction then you should rollback the transaction before +** continuing. +** +** ^[SQLITE_DONE] means that the statement has finished executing +** successfully. sqlite3_step() should not be called again on this virtual +** machine without first calling [sqlite3_reset()] to reset the virtual +** machine back to its initial state. +** +** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] +** is returned each time a new row of data is ready for processing by the +** caller. The values may be accessed using the [column access functions]. +** sqlite3_step() is called again to retrieve the next row of data. +** +** ^[SQLITE_ERROR] means that a run-time error (such as a constraint +** violation) has occurred. sqlite3_step() should not be called again on +** the VM. More information may be found by calling [sqlite3_errmsg()]. +** ^With the legacy interface, a more specific error code (for example, +** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) +** can be obtained by calling [sqlite3_reset()] on the +** [prepared statement]. ^In the "v2" interface, +** the more specific error code is returned directly by sqlite3_step(). +** +** [SQLITE_MISUSE] means that the this routine was called inappropriately. +** Perhaps it was called on a [prepared statement] that has +** already been [sqlite3_finalize | finalized] or on one that had +** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could +** be the case that the same database connection is being used by two or +** more threads at the same moment in time. +** +** For all versions of SQLite up to and including 3.6.23.1, a call to +** [sqlite3_reset()] was required after sqlite3_step() returned anything +** other than [SQLITE_ROW] before any subsequent invocation of +** sqlite3_step(). Failure to reset the prepared statement using +** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from +** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began +** calling [sqlite3_reset()] automatically in this circumstance rather +** than returning [SQLITE_MISUSE]. This is not considered a compatibility +** break because any application that ever receives an SQLITE_MISUSE error +** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option +** can be used to restore the legacy behavior. +** +** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() +** API always returns a generic error code, [SQLITE_ERROR], following any +** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call +** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the +** specific [error codes] that better describes the error. +** We admit that this is a goofy design. The problem has been fixed +** with the "v2" interface. If you prepare all of your SQL statements +** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead +** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, +** then the more specific [error codes] are returned directly +** by sqlite3_step(). The use of the "v2" interface is recommended. +*/ +int sqlite3_step(sqlite3_stmt*); + +/* +** CAPI3REF: Number of columns in a result set +** +** ^The sqlite3_data_count(P) interface returns the number of columns in the +** current row of the result set of [prepared statement] P. +** ^If prepared statement P does not have results ready to return +** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of +** interfaces) then sqlite3_data_count(P) returns 0. +** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. +** ^The sqlite3_data_count(P) routine returns 0 if the previous call to +** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) +** will return non-zero if previous call to [sqlite3_step](P) returned +** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] +** where it always returns zero since each step of that multi-step +** pragma returns 0 columns of data. +** +** See also: [sqlite3_column_count()] +*/ +int sqlite3_data_count(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Fundamental Datatypes +** KEYWORDS: SQLITE_TEXT +** +** ^(Every value in SQLite has one of five fundamental datatypes: +** +** <ul> +** <li> 64-bit signed integer +** <li> 64-bit IEEE floating point number +** <li> string +** <li> BLOB +** <li> NULL +** </ul>)^ +** +** These constants are codes for each of those types. +** +** Note that the SQLITE_TEXT constant was also used in SQLite version 2 +** for a completely different meaning. Software that links against both +** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not +** SQLITE_TEXT. +*/ +#define SQLITE_INTEGER 1 +#define SQLITE_FLOAT 2 +#define SQLITE_BLOB 4 +#define SQLITE_NULL 5 +#ifdef SQLITE_TEXT +# undef SQLITE_TEXT +#else +# define SQLITE_TEXT 3 +#endif +#define SQLITE3_TEXT 3 + +/* +** CAPI3REF: Result Values From A Query +** KEYWORDS: {column access functions} +** +** These routines form the "result set" interface. +** +** ^These routines return information about a single column of the current +** result row of a query. ^In every case the first argument is a pointer +** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] +** that was returned from [sqlite3_prepare_v2()] or one of its variants) +** and the second argument is the index of the column for which information +** should be returned. ^The leftmost column of the result set has the index 0. +** ^The number of columns in the result can be determined using +** [sqlite3_column_count()]. +** +** If the SQL statement does not currently point to a valid row, or if the +** column index is out of range, the result is undefined. +** These routines may only be called when the most recent call to +** [sqlite3_step()] has returned [SQLITE_ROW] and neither +** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. +** If any of these routines are called after [sqlite3_reset()] or +** [sqlite3_finalize()] or after [sqlite3_step()] has returned +** something other than [SQLITE_ROW], the results are undefined. +** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] +** are called from a different thread while any of these routines +** are pending, then the results are undefined. +** +** ^The sqlite3_column_type() routine returns the +** [SQLITE_INTEGER | datatype code] for the initial data type +** of the result column. ^The returned value is one of [SQLITE_INTEGER], +** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value +** returned by sqlite3_column_type() is only meaningful if no type +** conversions have occurred as described below. After a type conversion, +** the value returned by sqlite3_column_type() is undefined. Future +** versions of SQLite may change the behavior of sqlite3_column_type() +** following a type conversion. +** +** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() +** routine returns the number of bytes in that BLOB or string. +** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts +** the string to UTF-8 and then returns the number of bytes. +** ^If the result is a numeric value then sqlite3_column_bytes() uses +** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns +** the number of bytes in that string. +** ^If the result is NULL, then sqlite3_column_bytes() returns zero. +** +** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() +** routine returns the number of bytes in that BLOB or string. +** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts +** the string to UTF-16 and then returns the number of bytes. +** ^If the result is a numeric value then sqlite3_column_bytes16() uses +** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns +** the number of bytes in that string. +** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. +** +** ^The values returned by [sqlite3_column_bytes()] and +** [sqlite3_column_bytes16()] do not include the zero terminators at the end +** of the string. ^For clarity: the values returned by +** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of +** bytes in the string, not the number of characters. +** +** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), +** even empty strings, are always zero terminated. ^The return +** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. +** +** ^The object returned by [sqlite3_column_value()] is an +** [unprotected sqlite3_value] object. An unprotected sqlite3_value object +** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. +** If the [unprotected sqlite3_value] object returned by +** [sqlite3_column_value()] is used in any other way, including calls +** to routines like [sqlite3_value_int()], [sqlite3_value_text()], +** or [sqlite3_value_bytes()], then the behavior is undefined. +** +** These routines attempt to convert the value where appropriate. ^For +** example, if the internal representation is FLOAT and a text result +** is requested, [sqlite3_snprintf()] is used internally to perform the +** conversion automatically. ^(The following table details the conversions +** that are applied: +** +** <blockquote> +** <table border="1"> +** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion +** +** <tr><td> NULL <td> INTEGER <td> Result is 0 +** <tr><td> NULL <td> FLOAT <td> Result is 0.0 +** <tr><td> NULL <td> TEXT <td> Result is NULL pointer +** <tr><td> NULL <td> BLOB <td> Result is NULL pointer +** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float +** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer +** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT +** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer +** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float +** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT +** <tr><td> TEXT <td> INTEGER <td> Use atoi() +** <tr><td> TEXT <td> FLOAT <td> Use atof() +** <tr><td> TEXT <td> BLOB <td> No change +** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() +** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() +** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed +** </table> +** </blockquote>)^ +** +** The table above makes reference to standard C library functions atoi() +** and atof(). SQLite does not really use these functions. It has its +** own equivalent internal routines. The atoi() and atof() names are +** used in the table for brevity and because they are familiar to most +** C programmers. +** +** Note that when type conversions occur, pointers returned by prior +** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or +** sqlite3_column_text16() may be invalidated. +** Type conversions and pointer invalidations might occur +** in the following cases: +** +** <ul> +** <li> The initial content is a BLOB and sqlite3_column_text() or +** sqlite3_column_text16() is called. A zero-terminator might +** need to be added to the string.</li> +** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or +** sqlite3_column_text16() is called. The content must be converted +** to UTF-16.</li> +** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or +** sqlite3_column_text() is called. The content must be converted +** to UTF-8.</li> +** </ul> +** +** ^Conversions between UTF-16be and UTF-16le are always done in place and do +** not invalidate a prior pointer, though of course the content of the buffer +** that the prior pointer references will have been modified. Other kinds +** of conversion are done in place when it is possible, but sometimes they +** are not possible and in those cases prior pointers are invalidated. +** +** The safest and easiest to remember policy is to invoke these routines +** in one of the following ways: +** +** <ul> +** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> +** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> +** </ul> +** +** In other words, you should call sqlite3_column_text(), +** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result +** into the desired format, then invoke sqlite3_column_bytes() or +** sqlite3_column_bytes16() to find the size of the result. Do not mix calls +** to sqlite3_column_text() or sqlite3_column_blob() with calls to +** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() +** with calls to sqlite3_column_bytes(). +** +** ^The pointers returned are valid until a type conversion occurs as +** described above, or until [sqlite3_step()] or [sqlite3_reset()] or +** [sqlite3_finalize()] is called. ^The memory space used to hold strings +** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned +** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into +** [sqlite3_free()]. +** +** ^(If a memory allocation error occurs during the evaluation of any +** of these routines, a default value is returned. The default value +** is either the integer 0, the floating point number 0.0, or a NULL +** pointer. Subsequent calls to [sqlite3_errcode()] will return +** [SQLITE_NOMEM].)^ +*/ +const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); +int sqlite3_column_bytes(sqlite3_stmt*, int iCol); +int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); +double sqlite3_column_double(sqlite3_stmt*, int iCol); +int sqlite3_column_int(sqlite3_stmt*, int iCol); +sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); +const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); +const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); +int sqlite3_column_type(sqlite3_stmt*, int iCol); +sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); + +/* +** CAPI3REF: Destroy A Prepared Statement Object +** +** ^The sqlite3_finalize() function is called to delete a [prepared statement]. +** ^If the most recent evaluation of the statement encountered no errors +** or if the statement is never been evaluated, then sqlite3_finalize() returns +** SQLITE_OK. ^If the most recent evaluation of statement S failed, then +** sqlite3_finalize(S) returns the appropriate [error code] or +** [extended error code]. +** +** ^The sqlite3_finalize(S) routine can be called at any point during +** the life cycle of [prepared statement] S: +** before statement S is ever evaluated, after +** one or more calls to [sqlite3_reset()], or after any call +** to [sqlite3_step()] regardless of whether or not the statement has +** completed execution. +** +** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. +** +** The application must finalize every [prepared statement] in order to avoid +** resource leaks. It is a grievous error for the application to try to use +** a prepared statement after it has been finalized. Any use of a prepared +** statement after it has been finalized can result in undefined and +** undesirable behavior such as segfaults and heap corruption. +*/ +int sqlite3_finalize(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Reset A Prepared Statement Object +** +** The sqlite3_reset() function is called to reset a [prepared statement] +** object back to its initial state, ready to be re-executed. +** ^Any SQL statement variables that had values bound to them using +** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. +** Use [sqlite3_clear_bindings()] to reset the bindings. +** +** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S +** back to the beginning of its program. +** +** ^If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], +** or if [sqlite3_step(S)] has never before been called on S, +** then [sqlite3_reset(S)] returns [SQLITE_OK]. +** +** ^If the most recent call to [sqlite3_step(S)] for the +** [prepared statement] S indicated an error, then +** [sqlite3_reset(S)] returns an appropriate [error code]. +** +** ^The [sqlite3_reset(S)] interface does not change the values +** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. +*/ +int sqlite3_reset(sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Create Or Redefine SQL Functions +** KEYWORDS: {function creation routines} +** KEYWORDS: {application-defined SQL function} +** KEYWORDS: {application-defined SQL functions} +** +** ^These functions (collectively known as "function creation routines") +** are used to add SQL functions or aggregates or to redefine the behavior +** of existing SQL functions or aggregates. The only differences between +** these routines are the text encoding expected for +** the second parameter (the name of the function being created) +** and the presence or absence of a destructor callback for +** the application data pointer. +** +** ^The first parameter is the [database connection] to which the SQL +** function is to be added. ^If an application uses more than one database +** connection then application-defined SQL functions must be added +** to each database connection separately. +** +** ^The second parameter is the name of the SQL function to be created or +** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 +** representation, exclusive of the zero-terminator. ^Note that the name +** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. +** ^Any attempt to create a function with a longer name +** will result in [SQLITE_MISUSE] being returned. +** +** ^The third parameter (nArg) +** is the number of arguments that the SQL function or +** aggregate takes. ^If this parameter is -1, then the SQL function or +** aggregate may take any number of arguments between 0 and the limit +** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third +** parameter is less than -1 or greater than 127 then the behavior is +** undefined. +** +** ^The fourth parameter, eTextRep, specifies what +** [SQLITE_UTF8 | text encoding] this SQL function prefers for +** its parameters. Every SQL function implementation must be able to work +** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be +** more efficient with one encoding than another. ^An application may +** invoke sqlite3_create_function() or sqlite3_create_function16() multiple +** times with the same function but with different values of eTextRep. +** ^When multiple implementations of the same function are available, SQLite +** will pick the one that involves the least amount of data conversion. +** If there is only a single implementation which does not care what text +** encoding is used, then the fourth argument should be [SQLITE_ANY]. +** +** ^(The fifth parameter is an arbitrary pointer. The implementation of the +** function can gain access to this pointer using [sqlite3_user_data()].)^ +** +** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are +** pointers to C-language functions that implement the SQL function or +** aggregate. ^A scalar SQL function requires an implementation of the xFunc +** callback only; NULL pointers must be passed as the xStep and xFinal +** parameters. ^An aggregate SQL function requires an implementation of xStep +** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing +** SQL function or aggregate, pass NULL pointers for all three function +** callbacks. +** +** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, +** then it is destructor for the application data pointer. +** The destructor is invoked when the function is deleted, either by being +** overloaded or when the database connection closes.)^ +** ^The destructor is also invoked if the call to +** sqlite3_create_function_v2() fails. +** ^When the destructor callback of the tenth parameter is invoked, it +** is passed a single argument which is a copy of the application data +** pointer which was the fifth parameter to sqlite3_create_function_v2(). +** +** ^It is permitted to register multiple implementations of the same +** functions with the same name but with either differing numbers of +** arguments or differing preferred text encodings. ^SQLite will use +** the implementation that most closely matches the way in which the +** SQL function is used. ^A function implementation with a non-negative +** nArg parameter is a better match than a function implementation with +** a negative nArg. ^A function where the preferred text encoding +** matches the database encoding is a better +** match than a function where the encoding is different. +** ^A function where the encoding difference is between UTF16le and UTF16be +** is a closer match than a function where the encoding difference is +** between UTF8 and UTF16. +** +** ^Built-in functions may be overloaded by new application-defined functions. +** +** ^An application-defined function is permitted to call other +** SQLite interfaces. However, such calls must not +** close the database connection nor finalize or reset the prepared +** statement in which the function is running. +*/ +int sqlite3_create_function( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); +int sqlite3_create_function16( + sqlite3 *db, + const void *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*) +); +int sqlite3_create_function_v2( + sqlite3 *db, + const char *zFunctionName, + int nArg, + int eTextRep, + void *pApp, + void (*xFunc)(sqlite3_context*,int,sqlite3_value**), + void (*xStep)(sqlite3_context*,int,sqlite3_value**), + void (*xFinal)(sqlite3_context*), + void(*xDestroy)(void*) +); + +/* +** CAPI3REF: Text Encodings +** +** These constant define integer codes that represent the various +** text encodings supported by SQLite. +*/ +#define SQLITE_UTF8 1 +#define SQLITE_UTF16LE 2 +#define SQLITE_UTF16BE 3 +#define SQLITE_UTF16 4 /* Use native byte order */ +#define SQLITE_ANY 5 /* sqlite3_create_function only */ +#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ + +/* +** CAPI3REF: Deprecated Functions +** DEPRECATED +** +** These functions are [deprecated]. In order to maintain +** backwards compatibility with older code, these functions continue +** to be supported. However, new applications should avoid +** the use of these functions. To help encourage people to avoid +** using these functions, we are not going to tell you what they do. +*/ +#ifndef SQLITE_OMIT_DEPRECATED +SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); +SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); +SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); +SQLITE_DEPRECATED int sqlite3_global_recover(void); +SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); +SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); +#endif + +/* +** CAPI3REF: Obtaining SQL Function Parameter Values +** +** The C-language implementation of SQL functions and aggregates uses +** this set of interface routines to access the parameter values on +** the function or aggregate. +** +** The xFunc (for scalar functions) or xStep (for aggregates) parameters +** to [sqlite3_create_function()] and [sqlite3_create_function16()] +** define callbacks that implement the SQL functions and aggregates. +** The 3rd parameter to these callbacks is an array of pointers to +** [protected sqlite3_value] objects. There is one [sqlite3_value] object for +** each parameter to the SQL function. These routines are used to +** extract values from the [sqlite3_value] objects. +** +** These routines work only with [protected sqlite3_value] objects. +** Any attempt to use these routines on an [unprotected sqlite3_value] +** object results in undefined behavior. +** +** ^These routines work just like the corresponding [column access functions] +** except that these routines take a single [protected sqlite3_value] object +** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. +** +** ^The sqlite3_value_text16() interface extracts a UTF-16 string +** in the native byte-order of the host machine. ^The +** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces +** extract UTF-16 strings as big-endian and little-endian respectively. +** +** ^(The sqlite3_value_numeric_type() interface attempts to apply +** numeric affinity to the value. This means that an attempt is +** made to convert the value to an integer or floating point. If +** such a conversion is possible without loss of information (in other +** words, if the value is a string that looks like a number) +** then the conversion is performed. Otherwise no conversion occurs. +** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ +** +** Please pay particular attention to the fact that the pointer returned +** from [sqlite3_value_blob()], [sqlite3_value_text()], or +** [sqlite3_value_text16()] can be invalidated by a subsequent call to +** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], +** or [sqlite3_value_text16()]. +** +** These routines must be called from the same thread as +** the SQL function that supplied the [sqlite3_value*] parameters. +*/ +const void *sqlite3_value_blob(sqlite3_value*); +int sqlite3_value_bytes(sqlite3_value*); +int sqlite3_value_bytes16(sqlite3_value*); +double sqlite3_value_double(sqlite3_value*); +int sqlite3_value_int(sqlite3_value*); +sqlite3_int64 sqlite3_value_int64(sqlite3_value*); +const unsigned char *sqlite3_value_text(sqlite3_value*); +const void *sqlite3_value_text16(sqlite3_value*); +const void *sqlite3_value_text16le(sqlite3_value*); +const void *sqlite3_value_text16be(sqlite3_value*); +int sqlite3_value_type(sqlite3_value*); +int sqlite3_value_numeric_type(sqlite3_value*); + +/* +** CAPI3REF: Obtain Aggregate Function Context +** +** Implementations of aggregate SQL functions use this +** routine to allocate memory for storing their state. +** +** ^The first time the sqlite3_aggregate_context(C,N) routine is called +** for a particular aggregate function, SQLite +** allocates N of memory, zeroes out that memory, and returns a pointer +** to the new memory. ^On second and subsequent calls to +** sqlite3_aggregate_context() for the same aggregate function instance, +** the same buffer is returned. Sqlite3_aggregate_context() is normally +** called once for each invocation of the xStep callback and then one +** last time when the xFinal callback is invoked. ^(When no rows match +** an aggregate query, the xStep() callback of the aggregate function +** implementation is never called and xFinal() is called exactly once. +** In those cases, sqlite3_aggregate_context() might be called for the +** first time from within xFinal().)^ +** +** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is +** less than or equal to zero or if a memory allocate error occurs. +** +** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is +** determined by the N parameter on first successful call. Changing the +** value of N in subsequent call to sqlite3_aggregate_context() within +** the same aggregate function instance will not resize the memory +** allocation.)^ +** +** ^SQLite automatically frees the memory allocated by +** sqlite3_aggregate_context() when the aggregate query concludes. +** +** The first parameter must be a copy of the +** [sqlite3_context | SQL function context] that is the first parameter +** to the xStep or xFinal callback routine that implements the aggregate +** function. +** +** This routine must be called from the same thread in which +** the aggregate SQL function is running. +*/ +void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); + +/* +** CAPI3REF: User Data For Functions +** +** ^The sqlite3_user_data() interface returns a copy of +** the pointer that was the pUserData parameter (the 5th parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. +** +** This routine must be called from the same thread in which +** the application-defined function is running. +*/ +void *sqlite3_user_data(sqlite3_context*); + +/* +** CAPI3REF: Database Connection For Functions +** +** ^The sqlite3_context_db_handle() interface returns a copy of +** the pointer to the [database connection] (the 1st parameter) +** of the [sqlite3_create_function()] +** and [sqlite3_create_function16()] routines that originally +** registered the application defined function. +*/ +sqlite3 *sqlite3_context_db_handle(sqlite3_context*); + +/* +** CAPI3REF: Function Auxiliary Data +** +** The following two functions may be used by scalar SQL functions to +** associate metadata with argument values. If the same value is passed to +** multiple invocations of the same SQL function during query execution, under +** some circumstances the associated metadata may be preserved. This may +** be used, for example, to add a regular-expression matching scalar +** function. The compiled version of the regular expression is stored as +** metadata associated with the SQL value passed as the regular expression +** pattern. The compiled regular expression can be reused on multiple +** invocations of the same function so that the original pattern string +** does not need to be recompiled on each invocation. +** +** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata +** associated by the sqlite3_set_auxdata() function with the Nth argument +** value to the application-defined function. ^If no metadata has been ever +** been set for the Nth argument of the function, or if the corresponding +** function parameter has changed since the meta-data was set, +** then sqlite3_get_auxdata() returns a NULL pointer. +** +** ^The sqlite3_set_auxdata() interface saves the metadata +** pointed to by its 3rd parameter as the metadata for the N-th +** argument of the application-defined function. Subsequent +** calls to sqlite3_get_auxdata() might return this data, if it has +** not been destroyed. +** ^If it is not NULL, SQLite will invoke the destructor +** function given by the 4th parameter to sqlite3_set_auxdata() on +** the metadata when the corresponding function parameter changes +** or when the SQL statement completes, whichever comes first. +** +** SQLite is free to call the destructor and drop metadata on any +** parameter of any function at any time. ^The only guarantee is that +** the destructor will be called before the metadata is dropped. +** +** ^(In practice, metadata is preserved between function calls for +** expressions that are constant at compile time. This includes literal +** values and [parameters].)^ +** +** These routines must be called from the same thread in which +** the SQL function is running. +*/ +void *sqlite3_get_auxdata(sqlite3_context*, int N); +void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); + + +/* +** CAPI3REF: Constants Defining Special Destructor Behavior +** +** These are special values for the destructor that is passed in as the +** final argument to routines like [sqlite3_result_blob()]. ^If the destructor +** argument is SQLITE_STATIC, it means that the content pointer is constant +** and will never change. It does not need to be destroyed. ^The +** SQLITE_TRANSIENT value means that the content will likely change in +** the near future and that SQLite should make its own private copy of +** the content before returning. +** +** The typedef is necessary to work around problems in certain +** C++ compilers. See ticket #2191. +*/ +typedef void (*sqlite3_destructor_type)(void*); +#define SQLITE_STATIC ((sqlite3_destructor_type)0) +#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) + +/* +** CAPI3REF: Setting The Result Of An SQL Function +** +** These routines are used by the xFunc or xFinal callbacks that +** implement SQL functions and aggregates. See +** [sqlite3_create_function()] and [sqlite3_create_function16()] +** for additional information. +** +** These functions work very much like the [parameter binding] family of +** functions used to bind values to host parameters in prepared statements. +** Refer to the [SQL parameter] documentation for additional information. +** +** ^The sqlite3_result_blob() interface sets the result from +** an application-defined function to be the BLOB whose content is pointed +** to by the second parameter and which is N bytes long where N is the +** third parameter. +** +** ^The sqlite3_result_zeroblob() interfaces set the result of +** the application-defined function to be a BLOB containing all zero +** bytes and N bytes in size, where N is the value of the 2nd parameter. +** +** ^The sqlite3_result_double() interface sets the result from +** an application-defined function to be a floating point value specified +** by its 2nd argument. +** +** ^The sqlite3_result_error() and sqlite3_result_error16() functions +** cause the implemented SQL function to throw an exception. +** ^SQLite uses the string pointed to by the +** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() +** as the text of an error message. ^SQLite interprets the error +** message string from sqlite3_result_error() as UTF-8. ^SQLite +** interprets the string from sqlite3_result_error16() as UTF-16 in native +** byte order. ^If the third parameter to sqlite3_result_error() +** or sqlite3_result_error16() is negative then SQLite takes as the error +** message all text up through the first zero character. +** ^If the third parameter to sqlite3_result_error() or +** sqlite3_result_error16() is non-negative then SQLite takes that many +** bytes (not characters) from the 2nd parameter as the error message. +** ^The sqlite3_result_error() and sqlite3_result_error16() +** routines make a private copy of the error message text before +** they return. Hence, the calling function can deallocate or +** modify the text after they return without harm. +** ^The sqlite3_result_error_code() function changes the error code +** returned by SQLite as a result of an error in a function. ^By default, +** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() +** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. +** +** ^The sqlite3_result_toobig() interface causes SQLite to throw an error +** indicating that a string or BLOB is too long to represent. +** +** ^The sqlite3_result_nomem() interface causes SQLite to throw an error +** indicating that a memory allocation failed. +** +** ^The sqlite3_result_int() interface sets the return value +** of the application-defined function to be the 32-bit signed integer +** value given in the 2nd argument. +** ^The sqlite3_result_int64() interface sets the return value +** of the application-defined function to be the 64-bit signed integer +** value given in the 2nd argument. +** +** ^The sqlite3_result_null() interface sets the return value +** of the application-defined function to be NULL. +** +** ^The sqlite3_result_text(), sqlite3_result_text16(), +** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces +** set the return value of the application-defined function to be +** a text string which is represented as UTF-8, UTF-16 native byte order, +** UTF-16 little endian, or UTF-16 big endian, respectively. +** ^SQLite takes the text result from the application from +** the 2nd parameter of the sqlite3_result_text* interfaces. +** ^If the 3rd parameter to the sqlite3_result_text* interfaces +** is negative, then SQLite takes result text from the 2nd parameter +** through the first zero character. +** ^If the 3rd parameter to the sqlite3_result_text* interfaces +** is non-negative, then as many bytes (not characters) of the text +** pointed to by the 2nd parameter are taken as the application-defined +** function result. If the 3rd parameter is non-negative, then it +** must be the byte offset into the string where the NUL terminator would +** appear if the string where NUL terminated. If any NUL characters occur +** in the string at a byte offset that is less than the value of the 3rd +** parameter, then the resulting string will contain embedded NULs and the +** result of expressions operating on strings with embedded NULs is undefined. +** ^If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that +** function as the destructor on the text or BLOB result when it has +** finished using that result. +** ^If the 4th parameter to the sqlite3_result_text* interfaces or to +** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite +** assumes that the text or BLOB result is in constant space and does not +** copy the content of the parameter nor call a destructor on the content +** when it has finished using that result. +** ^If the 4th parameter to the sqlite3_result_text* interfaces +** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT +** then SQLite makes a copy of the result into space obtained from +** from [sqlite3_malloc()] before it returns. +** +** ^The sqlite3_result_value() interface sets the result of +** the application-defined function to be a copy the +** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The +** sqlite3_result_value() interface makes a copy of the [sqlite3_value] +** so that the [sqlite3_value] specified in the parameter may change or +** be deallocated after sqlite3_result_value() returns without harm. +** ^A [protected sqlite3_value] object may always be used where an +** [unprotected sqlite3_value] object is required, so either +** kind of [sqlite3_value] object can be used with this interface. +** +** If these routines are called from within the different thread +** than the one containing the application-defined function that received +** the [sqlite3_context] pointer, the results are undefined. +*/ +void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); +void sqlite3_result_double(sqlite3_context*, double); +void sqlite3_result_error(sqlite3_context*, const char*, int); +void sqlite3_result_error16(sqlite3_context*, const void*, int); +void sqlite3_result_error_toobig(sqlite3_context*); +void sqlite3_result_error_nomem(sqlite3_context*); +void sqlite3_result_error_code(sqlite3_context*, int); +void sqlite3_result_int(sqlite3_context*, int); +void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); +void sqlite3_result_null(sqlite3_context*); +void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); +void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); +void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); +void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); +void sqlite3_result_value(sqlite3_context*, sqlite3_value*); +void sqlite3_result_zeroblob(sqlite3_context*, int n); + +/* +** CAPI3REF: Define New Collating Sequences +** +** ^These functions add, remove, or modify a [collation] associated +** with the [database connection] specified as the first argument. +** +** ^The name of the collation is a UTF-8 string +** for sqlite3_create_collation() and sqlite3_create_collation_v2() +** and a UTF-16 string in native byte order for sqlite3_create_collation16(). +** ^Collation names that compare equal according to [sqlite3_strnicmp()] are +** considered to be the same name. +** +** ^(The third argument (eTextRep) must be one of the constants: +** <ul> +** <li> [SQLITE_UTF8], +** <li> [SQLITE_UTF16LE], +** <li> [SQLITE_UTF16BE], +** <li> [SQLITE_UTF16], or +** <li> [SQLITE_UTF16_ALIGNED]. +** </ul>)^ +** ^The eTextRep argument determines the encoding of strings passed +** to the collating function callback, xCallback. +** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep +** force strings to be UTF16 with native byte order. +** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin +** on an even byte address. +** +** ^The fourth argument, pArg, is an application data pointer that is passed +** through as the first argument to the collating function callback. +** +** ^The fifth argument, xCallback, is a pointer to the collating function. +** ^Multiple collating functions can be registered using the same name but +** with different eTextRep parameters and SQLite will use whichever +** function requires the least amount of data transformation. +** ^If the xCallback argument is NULL then the collating function is +** deleted. ^When all collating functions having the same name are deleted, +** that collation is no longer usable. +** +** ^The collating function callback is invoked with a copy of the pArg +** application data pointer and with two strings in the encoding specified +** by the eTextRep argument. The collating function must return an +** integer that is negative, zero, or positive +** if the first string is less than, equal to, or greater than the second, +** respectively. A collating function must always return the same answer +** given the same inputs. If two or more collating functions are registered +** to the same collation name (using different eTextRep values) then all +** must give an equivalent answer when invoked with equivalent strings. +** The collating function must obey the following properties for all +** strings A, B, and C: +** +** <ol> +** <li> If A==B then B==A. +** <li> If A==B and B==C then A==C. +** <li> If A<B THEN B>A. +** <li> If A<B and B<C then A<C. +** </ol> +** +** If a collating function fails any of the above constraints and that +** collating function is registered and used, then the behavior of SQLite +** is undefined. +** +** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() +** with the addition that the xDestroy callback is invoked on pArg when +** the collating function is deleted. +** ^Collating functions are deleted when they are overridden by later +** calls to the collation creation functions or when the +** [database connection] is closed using [sqlite3_close()]. +** +** ^The xDestroy callback is <u>not</u> called if the +** sqlite3_create_collation_v2() function fails. Applications that invoke +** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should +** check the return code and dispose of the application data pointer +** themselves rather than expecting SQLite to deal with it for them. +** This is different from every other SQLite interface. The inconsistency +** is unfortunate but cannot be changed without breaking backwards +** compatibility. +** +** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. +*/ +int sqlite3_create_collation( + sqlite3*, + const char *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*) +); +int sqlite3_create_collation_v2( + sqlite3*, + const char *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*), + void(*xDestroy)(void*) +); +int sqlite3_create_collation16( + sqlite3*, + const void *zName, + int eTextRep, + void *pArg, + int(*xCompare)(void*,int,const void*,int,const void*) +); + +/* +** CAPI3REF: Collation Needed Callbacks +** +** ^To avoid having to register all collation sequences before a database +** can be used, a single callback function may be registered with the +** [database connection] to be invoked whenever an undefined collation +** sequence is required. +** +** ^If the function is registered using the sqlite3_collation_needed() API, +** then it is passed the names of undefined collation sequences as strings +** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, +** the names are passed as UTF-16 in machine native byte order. +** ^A call to either function replaces the existing collation-needed callback. +** +** ^(When the callback is invoked, the first argument passed is a copy +** of the second argument to sqlite3_collation_needed() or +** sqlite3_collation_needed16(). The second argument is the database +** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], +** or [SQLITE_UTF16LE], indicating the most desirable form of the collation +** sequence function required. The fourth parameter is the name of the +** required collation sequence.)^ +** +** The callback function should register the desired collation using +** [sqlite3_create_collation()], [sqlite3_create_collation16()], or +** [sqlite3_create_collation_v2()]. +*/ +int sqlite3_collation_needed( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const char*) +); +int sqlite3_collation_needed16( + sqlite3*, + void*, + void(*)(void*,sqlite3*,int eTextRep,const void*) +); + +#ifdef SQLITE_HAS_CODEC +/* +** Specify the key for an encrypted database. This routine should be +** called right after sqlite3_open(). +** +** The code to implement this API is not available in the public release +** of SQLite. +*/ +int sqlite3_key( + sqlite3 *db, /* Database to be rekeyed */ + const void *pKey, int nKey /* The key */ +); + +/* +** Change the key on an open database. If the current database is not +** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the +** database is decrypted. +** +** The code to implement this API is not available in the public release +** of SQLite. +*/ +int sqlite3_rekey( + sqlite3 *db, /* Database to be rekeyed */ + const void *pKey, int nKey /* The new key */ +); + +/* +** Specify the activation key for a SEE database. Unless +** activated, none of the SEE routines will work. +*/ +void sqlite3_activate_see( + const char *zPassPhrase /* Activation phrase */ +); +#endif + +#ifdef SQLITE_ENABLE_CEROD +/* +** Specify the activation key for a CEROD database. Unless +** activated, none of the CEROD routines will work. +*/ +void sqlite3_activate_cerod( + const char *zPassPhrase /* Activation phrase */ +); +#endif + +/* +** CAPI3REF: Suspend Execution For A Short Time +** +** The sqlite3_sleep() function causes the current thread to suspend execution +** for at least a number of milliseconds specified in its parameter. +** +** If the operating system does not support sleep requests with +** millisecond time resolution, then the time will be rounded up to +** the nearest second. The number of milliseconds of sleep actually +** requested from the operating system is returned. +** +** ^SQLite implements this interface by calling the xSleep() +** method of the default [sqlite3_vfs] object. If the xSleep() method +** of the default VFS is not implemented correctly, or not implemented at +** all, then the behavior of sqlite3_sleep() may deviate from the description +** in the previous paragraphs. +*/ +int sqlite3_sleep(int); + +/* +** CAPI3REF: Name Of The Folder Holding Temporary Files +** +** ^(If this global variable is made to point to a string which is +** the name of a folder (a.k.a. directory), then all temporary files +** created by SQLite when using a built-in [sqlite3_vfs | VFS] +** will be placed in that directory.)^ ^If this variable +** is a NULL pointer, then SQLite performs a search for an appropriate +** temporary file directory. +** +** It is not safe to read or modify this variable in more than one +** thread at a time. It is not safe to read or modify this variable +** if a [database connection] is being used at the same time in a separate +** thread. +** It is intended that this variable be set once +** as part of process initialization and before any SQLite interface +** routines have been called and that this variable remain unchanged +** thereafter. +** +** ^The [temp_store_directory pragma] may modify this variable and cause +** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, +** the [temp_store_directory pragma] always assumes that any string +** that this variable points to is held in memory obtained from +** [sqlite3_malloc] and the pragma may attempt to free that memory +** using [sqlite3_free]. +** Hence, if this variable is modified directly, either it should be +** made NULL or made to point to memory obtained from [sqlite3_malloc] +** or else the use of the [temp_store_directory pragma] should be avoided. +*/ +SQLITE_EXTERN char *sqlite3_temp_directory; + +/* +** CAPI3REF: Test For Auto-Commit Mode +** KEYWORDS: {autocommit mode} +** +** ^The sqlite3_get_autocommit() interface returns non-zero or +** zero if the given database connection is or is not in autocommit mode, +** respectively. ^Autocommit mode is on by default. +** ^Autocommit mode is disabled by a [BEGIN] statement. +** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. +** +** If certain kinds of errors occur on a statement within a multi-statement +** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], +** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the +** transaction might be rolled back automatically. The only way to +** find out whether SQLite automatically rolled back the transaction after +** an error is to use this function. +** +** If another thread changes the autocommit status of the database +** connection while this routine is running, then the return value +** is undefined. +*/ +int sqlite3_get_autocommit(sqlite3*); + +/* +** CAPI3REF: Find The Database Handle Of A Prepared Statement +** +** ^The sqlite3_db_handle interface returns the [database connection] handle +** to which a [prepared statement] belongs. ^The [database connection] +** returned by sqlite3_db_handle is the same [database connection] +** that was the first argument +** to the [sqlite3_prepare_v2()] call (or its variants) that was used to +** create the statement in the first place. +*/ +sqlite3 *sqlite3_db_handle(sqlite3_stmt*); + +/* +** CAPI3REF: Find the next prepared statement +** +** ^This interface returns a pointer to the next [prepared statement] after +** pStmt associated with the [database connection] pDb. ^If pStmt is NULL +** then this interface returns a pointer to the first prepared statement +** associated with the database connection pDb. ^If no prepared statement +** satisfies the conditions of this routine, it returns NULL. +** +** The [database connection] pointer D in a call to +** [sqlite3_next_stmt(D,S)] must refer to an open database +** connection and in particular must not be a NULL pointer. +*/ +sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); + +/* +** CAPI3REF: Commit And Rollback Notification Callbacks +** +** ^The sqlite3_commit_hook() interface registers a callback +** function to be invoked whenever a transaction is [COMMIT | committed]. +** ^Any callback set by a previous call to sqlite3_commit_hook() +** for the same database connection is overridden. +** ^The sqlite3_rollback_hook() interface registers a callback +** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. +** ^Any callback set by a previous call to sqlite3_rollback_hook() +** for the same database connection is overridden. +** ^The pArg argument is passed through to the callback. +** ^If the callback on a commit hook function returns non-zero, +** then the commit is converted into a rollback. +** +** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions +** return the P argument from the previous call of the same function +** on the same [database connection] D, or NULL for +** the first call for each function on D. +** +** The callback implementation must not do anything that will modify +** the database connection that invoked the callback. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the commit +** or rollback hook in the first place. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** ^Registering a NULL function disables the callback. +** +** ^When the commit hook callback routine returns zero, the [COMMIT] +** operation is allowed to continue normally. ^If the commit hook +** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. +** ^The rollback hook is invoked on a rollback that results from a commit +** hook returning non-zero, just as it would be with any other rollback. +** +** ^For the purposes of this API, a transaction is said to have been +** rolled back if an explicit "ROLLBACK" statement is executed, or +** an error or constraint causes an implicit rollback to occur. +** ^The rollback callback is not invoked if a transaction is +** automatically rolled back because the database connection is closed. +** +** See also the [sqlite3_update_hook()] interface. +*/ +void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); +void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); + +/* +** CAPI3REF: Data Change Notification Callbacks +** +** ^The sqlite3_update_hook() interface registers a callback function +** with the [database connection] identified by the first argument +** to be invoked whenever a row is updated, inserted or deleted. +** ^Any callback set by a previous call to this function +** for the same database connection is overridden. +** +** ^The second argument is a pointer to the function to invoke when a +** row is updated, inserted or deleted. +** ^The first argument to the callback is a copy of the third argument +** to sqlite3_update_hook(). +** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], +** or [SQLITE_UPDATE], depending on the operation that caused the callback +** to be invoked. +** ^The third and fourth arguments to the callback contain pointers to the +** database and table name containing the affected row. +** ^The final callback parameter is the [rowid] of the row. +** ^In the case of an update, this is the [rowid] after the update takes place. +** +** ^(The update hook is not invoked when internal system tables are +** modified (i.e. sqlite_master and sqlite_sequence).)^ +** +** ^In the current implementation, the update hook +** is not invoked when duplication rows are deleted because of an +** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook +** invoked when rows are deleted using the [truncate optimization]. +** The exceptions defined in this paragraph might change in a future +** release of SQLite. +** +** The update hook implementation must not do anything that will modify +** the database connection that invoked the update hook. Any actions +** to modify the database connection must be deferred until after the +** completion of the [sqlite3_step()] call that triggered the update hook. +** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their +** database connections for the meaning of "modify" in this paragraph. +** +** ^The sqlite3_update_hook(D,C,P) function +** returns the P argument from the previous call +** on the same [database connection] D, or NULL for +** the first call on D. +** +** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] +** interfaces. +*/ +void *sqlite3_update_hook( + sqlite3*, + void(*)(void *,int ,char const *,char const *,sqlite3_int64), + void* +); + +/* +** CAPI3REF: Enable Or Disable Shared Pager Cache +** KEYWORDS: {shared cache} +** +** ^(This routine enables or disables the sharing of the database cache +** and schema data structures between [database connection | connections] +** to the same database. Sharing is enabled if the argument is true +** and disabled if the argument is false.)^ +** +** ^Cache sharing is enabled and disabled for an entire process. +** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, +** sharing was enabled or disabled for each thread separately. +** +** ^(The cache sharing mode set by this interface effects all subsequent +** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. +** Existing database connections continue use the sharing mode +** that was in effect at the time they were opened.)^ +** +** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled +** successfully. An [error code] is returned otherwise.)^ +** +** ^Shared cache is disabled by default. But this might change in +** future releases of SQLite. Applications that care about shared +** cache setting should set it explicitly. +** +** See Also: [SQLite Shared-Cache Mode] +*/ +int sqlite3_enable_shared_cache(int); + +/* +** CAPI3REF: Attempt To Free Heap Memory +** +** ^The sqlite3_release_memory() interface attempts to free N bytes +** of heap memory by deallocating non-essential memory allocations +** held by the database library. Memory used to cache database +** pages to improve performance is an example of non-essential memory. +** ^sqlite3_release_memory() returns the number of bytes actually freed, +** which might be more or less than the amount requested. +** ^The sqlite3_release_memory() routine is a no-op returning zero +** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. +*/ +int sqlite3_release_memory(int); + +/* +** CAPI3REF: Impose A Limit On Heap Size +** +** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the +** soft limit on the amount of heap memory that may be allocated by SQLite. +** ^SQLite strives to keep heap memory utilization below the soft heap +** limit by reducing the number of pages held in the page cache +** as heap memory usages approaches the limit. +** ^The soft heap limit is "soft" because even though SQLite strives to stay +** below the limit, it will exceed the limit rather than generate +** an [SQLITE_NOMEM] error. In other words, the soft heap limit +** is advisory only. +** +** ^The return value from sqlite3_soft_heap_limit64() is the size of +** the soft heap limit prior to the call. ^If the argument N is negative +** then no change is made to the soft heap limit. Hence, the current +** size of the soft heap limit can be determined by invoking +** sqlite3_soft_heap_limit64() with a negative argument. +** +** ^If the argument N is zero then the soft heap limit is disabled. +** +** ^(The soft heap limit is not enforced in the current implementation +** if one or more of following conditions are true: +** +** <ul> +** <li> The soft heap limit is set to zero. +** <li> Memory accounting is disabled using a combination of the +** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and +** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. +** <li> An alternative page cache implementation is specified using +** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...). +** <li> The page cache allocates from its own memory pool supplied +** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than +** from the heap. +** </ul>)^ +** +** Beginning with SQLite version 3.7.3, the soft heap limit is enforced +** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] +** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], +** the soft heap limit is enforced on every memory allocation. Without +** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced +** when memory is allocated by the page cache. Testing suggests that because +** the page cache is the predominate memory user in SQLite, most +** applications will achieve adequate soft heap limit enforcement without +** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. +** +** The circumstances under which SQLite will enforce the soft heap limit may +** changes in future releases of SQLite. +*/ +sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); + +/* +** CAPI3REF: Deprecated Soft Heap Limit Interface +** DEPRECATED +** +** This is a deprecated version of the [sqlite3_soft_heap_limit64()] +** interface. This routine is provided for historical compatibility +** only. All new applications should use the +** [sqlite3_soft_heap_limit64()] interface rather than this one. +*/ +SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); + + +/* +** CAPI3REF: Extract Metadata About A Column Of A Table +** +** ^This routine returns metadata about a specific column of a specific +** database table accessible using the [database connection] handle +** passed as the first function argument. +** +** ^The column is identified by the second, third and fourth parameters to +** this function. ^The second parameter is either the name of the database +** (i.e. "main", "temp", or an attached database) containing the specified +** table or NULL. ^If it is NULL, then all attached databases are searched +** for the table using the same algorithm used by the database engine to +** resolve unqualified table references. +** +** ^The third and fourth parameters to this function are the table and column +** name of the desired column, respectively. Neither of these parameters +** may be NULL. +** +** ^Metadata is returned by writing to the memory locations passed as the 5th +** and subsequent parameters to this function. ^Any of these arguments may be +** NULL, in which case the corresponding element of metadata is omitted. +** +** ^(<blockquote> +** <table border="1"> +** <tr><th> Parameter <th> Output<br>Type <th> Description +** +** <tr><td> 5th <td> const char* <td> Data type +** <tr><td> 6th <td> const char* <td> Name of default collation sequence +** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint +** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY +** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] +** </table> +** </blockquote>)^ +** +** ^The memory pointed to by the character pointers returned for the +** declaration type and collation sequence is valid only until the next +** call to any SQLite API function. +** +** ^If the specified table is actually a view, an [error code] is returned. +** +** ^If the specified column is "rowid", "oid" or "_rowid_" and an +** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output +** parameters are set for the explicitly declared column. ^(If there is no +** explicitly declared [INTEGER PRIMARY KEY] column, then the output +** parameters are set as follows: +** +** <pre> +** data type: "INTEGER" +** collation sequence: "BINARY" +** not null: 0 +** primary key: 1 +** auto increment: 0 +** </pre>)^ +** +** ^(This function may load one or more schemas from database files. If an +** error occurs during this process, or if the requested table or column +** cannot be found, an [error code] is returned and an error message left +** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ +** +** ^This API is only available if the library was compiled with the +** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. +*/ +int sqlite3_table_column_metadata( + sqlite3 *db, /* Connection handle */ + const char *zDbName, /* Database name or NULL */ + const char *zTableName, /* Table name */ + const char *zColumnName, /* Column name */ + char const **pzDataType, /* OUTPUT: Declared data type */ + char const **pzCollSeq, /* OUTPUT: Collation sequence name */ + int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ + int *pPrimaryKey, /* OUTPUT: True if column part of PK */ + int *pAutoinc /* OUTPUT: True if column is auto-increment */ +); + +/* +** CAPI3REF: Load An Extension +** +** ^This interface loads an SQLite extension library from the named file. +** +** ^The sqlite3_load_extension() interface attempts to load an +** SQLite extension library contained in the file zFile. +** +** ^The entry point is zProc. +** ^zProc may be 0, in which case the name of the entry point +** defaults to "sqlite3_extension_init". +** ^The sqlite3_load_extension() interface returns +** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. +** ^If an error occurs and pzErrMsg is not 0, then the +** [sqlite3_load_extension()] interface shall attempt to +** fill *pzErrMsg with error message text stored in memory +** obtained from [sqlite3_malloc()]. The calling function +** should free this memory by calling [sqlite3_free()]. +** +** ^Extension loading must be enabled using +** [sqlite3_enable_load_extension()] prior to calling this API, +** otherwise an error will be returned. +** +** See also the [load_extension() SQL function]. +*/ +int sqlite3_load_extension( + sqlite3 *db, /* Load the extension into this database connection */ + const char *zFile, /* Name of the shared library containing extension */ + const char *zProc, /* Entry point. Derived from zFile if 0 */ + char **pzErrMsg /* Put error message here if not 0 */ +); + +/* +** CAPI3REF: Enable Or Disable Extension Loading +** +** ^So as not to open security holes in older applications that are +** unprepared to deal with extension loading, and as a means of disabling +** extension loading while evaluating user-entered SQL, the following API +** is provided to turn the [sqlite3_load_extension()] mechanism on and off. +** +** ^Extension loading is off by default. See ticket #1863. +** ^Call the sqlite3_enable_load_extension() routine with onoff==1 +** to turn extension loading on and call it with onoff==0 to turn +** it back off again. +*/ +int sqlite3_enable_load_extension(sqlite3 *db, int onoff); + +/* +** CAPI3REF: Automatically Load Statically Linked Extensions +** +** ^This interface causes the xEntryPoint() function to be invoked for +** each new [database connection] that is created. The idea here is that +** xEntryPoint() is the entry point for a statically linked SQLite extension +** that is to be automatically loaded into all new database connections. +** +** ^(Even though the function prototype shows that xEntryPoint() takes +** no arguments and returns void, SQLite invokes xEntryPoint() with three +** arguments and expects and integer result as if the signature of the +** entry point where as follows: +** +** <blockquote><pre> +** int xEntryPoint( +** sqlite3 *db, +** const char **pzErrMsg, +** const struct sqlite3_api_routines *pThunk +** ); +** </pre></blockquote>)^ +** +** If the xEntryPoint routine encounters an error, it should make *pzErrMsg +** point to an appropriate error message (obtained from [sqlite3_mprintf()]) +** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg +** is NULL before calling the xEntryPoint(). ^SQLite will invoke +** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any +** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], +** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. +** +** ^Calling sqlite3_auto_extension(X) with an entry point X that is already +** on the list of automatic extensions is a harmless no-op. ^No entry point +** will be called more than once for each database connection that is opened. +** +** See also: [sqlite3_reset_auto_extension()]. +*/ +int sqlite3_auto_extension(void (*xEntryPoint)(void)); + +/* +** CAPI3REF: Reset Automatic Extension Loading +** +** ^This interface disables all automatic extensions previously +** registered using [sqlite3_auto_extension()]. +*/ +void sqlite3_reset_auto_extension(void); + +/* +** The interface to the virtual-table mechanism is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +*/ + +/* +** Structures used by the virtual table interface +*/ +typedef struct sqlite3_vtab sqlite3_vtab; +typedef struct sqlite3_index_info sqlite3_index_info; +typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; +typedef struct sqlite3_module sqlite3_module; + +/* +** CAPI3REF: Virtual Table Object +** KEYWORDS: sqlite3_module {virtual table module} +** +** This structure, sometimes called a "virtual table module", +** defines the implementation of a [virtual tables]. +** This structure consists mostly of methods for the module. +** +** ^A virtual table module is created by filling in a persistent +** instance of this structure and passing a pointer to that instance +** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. +** ^The registration remains valid until it is replaced by a different +** module or until the [database connection] closes. The content +** of this structure must not change while it is registered with +** any database connection. +*/ +struct sqlite3_module { + int iVersion; + int (*xCreate)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xConnect)(sqlite3*, void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVTab, char**); + int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); + int (*xDisconnect)(sqlite3_vtab *pVTab); + int (*xDestroy)(sqlite3_vtab *pVTab); + int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); + int (*xClose)(sqlite3_vtab_cursor*); + int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, + int argc, sqlite3_value **argv); + int (*xNext)(sqlite3_vtab_cursor*); + int (*xEof)(sqlite3_vtab_cursor*); + int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); + int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); + int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); + int (*xBegin)(sqlite3_vtab *pVTab); + int (*xSync)(sqlite3_vtab *pVTab); + int (*xCommit)(sqlite3_vtab *pVTab); + int (*xRollback)(sqlite3_vtab *pVTab); + int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, + void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), + void **ppArg); + int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); + /* The methods above are in version 1 of the sqlite_module object. Those + ** below are for version 2 and greater. */ + int (*xSavepoint)(sqlite3_vtab *pVTab, int); + int (*xRelease)(sqlite3_vtab *pVTab, int); + int (*xRollbackTo)(sqlite3_vtab *pVTab, int); +}; + +/* +** CAPI3REF: Virtual Table Indexing Information +** KEYWORDS: sqlite3_index_info +** +** The sqlite3_index_info structure and its substructures is used as part +** of the [virtual table] interface to +** pass information into and receive the reply from the [xBestIndex] +** method of a [virtual table module]. The fields under **Inputs** are the +** inputs to xBestIndex and are read-only. xBestIndex inserts its +** results into the **Outputs** fields. +** +** ^(The aConstraint[] array records WHERE clause constraints of the form: +** +** <blockquote>column OP expr</blockquote> +** +** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is +** stored in aConstraint[].op using one of the +** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ +** ^(The index of the column is stored in +** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the +** expr on the right-hand side can be evaluated (and thus the constraint +** is usable) and false if it cannot.)^ +** +** ^The optimizer automatically inverts terms of the form "expr OP column" +** and makes other simplifications to the WHERE clause in an attempt to +** get as many WHERE clause terms into the form shown above as possible. +** ^The aConstraint[] array only reports WHERE clause terms that are +** relevant to the particular virtual table being queried. +** +** ^Information about the ORDER BY clause is stored in aOrderBy[]. +** ^Each term of aOrderBy records a column of the ORDER BY clause. +** +** The [xBestIndex] method must fill aConstraintUsage[] with information +** about what parameters to pass to xFilter. ^If argvIndex>0 then +** the right-hand side of the corresponding aConstraint[] is evaluated +** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit +** is true, then the constraint is assumed to be fully handled by the +** virtual table and is not checked again by SQLite.)^ +** +** ^The idxNum and idxPtr values are recorded and passed into the +** [xFilter] method. +** ^[sqlite3_free()] is used to free idxPtr if and only if +** needToFreeIdxPtr is true. +** +** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in +** the correct order to satisfy the ORDER BY clause so that no separate +** sorting step is required. +** +** ^The estimatedCost value is an estimate of the cost of doing the +** particular lookup. A full scan of a table with N entries should have +** a cost of N. A binary search of a table of N entries should have a +** cost of approximately log(N). +*/ +struct sqlite3_index_info { + /* Inputs */ + int nConstraint; /* Number of entries in aConstraint */ + struct sqlite3_index_constraint { + int iColumn; /* Column on left-hand side of constraint */ + unsigned char op; /* Constraint operator */ + unsigned char usable; /* True if this constraint is usable */ + int iTermOffset; /* Used internally - xBestIndex should ignore */ + } *aConstraint; /* Table of WHERE clause constraints */ + int nOrderBy; /* Number of terms in the ORDER BY clause */ + struct sqlite3_index_orderby { + int iColumn; /* Column number */ + unsigned char desc; /* True for DESC. False for ASC. */ + } *aOrderBy; /* The ORDER BY clause */ + /* Outputs */ + struct sqlite3_index_constraint_usage { + int argvIndex; /* if >0, constraint is part of argv to xFilter */ + unsigned char omit; /* Do not code a test for this constraint */ + } *aConstraintUsage; + int idxNum; /* Number used to identify the index */ + char *idxStr; /* String, possibly obtained from sqlite3_malloc */ + int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ + int orderByConsumed; /* True if output is already ordered */ + double estimatedCost; /* Estimated cost of using this index */ +}; + +/* +** CAPI3REF: Virtual Table Constraint Operator Codes +** +** These macros defined the allowed values for the +** [sqlite3_index_info].aConstraint[].op field. Each value represents +** an operator that is part of a constraint term in the wHERE clause of +** a query that uses a [virtual table]. +*/ +#define SQLITE_INDEX_CONSTRAINT_EQ 2 +#define SQLITE_INDEX_CONSTRAINT_GT 4 +#define SQLITE_INDEX_CONSTRAINT_LE 8 +#define SQLITE_INDEX_CONSTRAINT_LT 16 +#define SQLITE_INDEX_CONSTRAINT_GE 32 +#define SQLITE_INDEX_CONSTRAINT_MATCH 64 + +/* +** CAPI3REF: Register A Virtual Table Implementation +** +** ^These routines are used to register a new [virtual table module] name. +** ^Module names must be registered before +** creating a new [virtual table] using the module and before using a +** preexisting [virtual table] for the module. +** +** ^The module name is registered on the [database connection] specified +** by the first parameter. ^The name of the module is given by the +** second parameter. ^The third parameter is a pointer to +** the implementation of the [virtual table module]. ^The fourth +** parameter is an arbitrary client data pointer that is passed through +** into the [xCreate] and [xConnect] methods of the virtual table module +** when a new virtual table is be being created or reinitialized. +** +** ^The sqlite3_create_module_v2() interface has a fifth parameter which +** is a pointer to a destructor for the pClientData. ^SQLite will +** invoke the destructor function (if it is not NULL) when SQLite +** no longer needs the pClientData pointer. ^The destructor will also +** be invoked if the call to sqlite3_create_module_v2() fails. +** ^The sqlite3_create_module() +** interface is equivalent to sqlite3_create_module_v2() with a NULL +** destructor. +*/ +int sqlite3_create_module( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData /* Client data for xCreate/xConnect */ +); +int sqlite3_create_module_v2( + sqlite3 *db, /* SQLite connection to register module with */ + const char *zName, /* Name of the module */ + const sqlite3_module *p, /* Methods for the module */ + void *pClientData, /* Client data for xCreate/xConnect */ + void(*xDestroy)(void*) /* Module destructor function */ +); + +/* +** CAPI3REF: Virtual Table Instance Object +** KEYWORDS: sqlite3_vtab +** +** Every [virtual table module] implementation uses a subclass +** of this object to describe a particular instance +** of the [virtual table]. Each subclass will +** be tailored to the specific needs of the module implementation. +** The purpose of this superclass is to define certain fields that are +** common to all module implementations. +** +** ^Virtual tables methods can set an error message by assigning a +** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should +** take care that any prior string is freed by a call to [sqlite3_free()] +** prior to assigning a new string to zErrMsg. ^After the error message +** is delivered up to the client application, the string will be automatically +** freed by sqlite3_free() and the zErrMsg field will be zeroed. +*/ +struct sqlite3_vtab { + const sqlite3_module *pModule; /* The module for this virtual table */ + int nRef; /* NO LONGER USED */ + char *zErrMsg; /* Error message from sqlite3_mprintf() */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Virtual Table Cursor Object +** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} +** +** Every [virtual table module] implementation uses a subclass of the +** following structure to describe cursors that point into the +** [virtual table] and are used +** to loop through the virtual table. Cursors are created using the +** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed +** by the [sqlite3_module.xClose | xClose] method. Cursors are used +** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods +** of the module. Each module implementation will define +** the content of a cursor structure to suit its own needs. +** +** This superclass exists in order to define fields of the cursor that +** are common to all implementations. +*/ +struct sqlite3_vtab_cursor { + sqlite3_vtab *pVtab; /* Virtual table of this cursor */ + /* Virtual table implementations will typically add additional fields */ +}; + +/* +** CAPI3REF: Declare The Schema Of A Virtual Table +** +** ^The [xCreate] and [xConnect] methods of a +** [virtual table module] call this interface +** to declare the format (the names and datatypes of the columns) of +** the virtual tables they implement. +*/ +int sqlite3_declare_vtab(sqlite3*, const char *zSQL); + +/* +** CAPI3REF: Overload A Function For A Virtual Table +** +** ^(Virtual tables can provide alternative implementations of functions +** using the [xFindFunction] method of the [virtual table module]. +** But global versions of those functions +** must exist in order to be overloaded.)^ +** +** ^(This API makes sure a global version of a function with a particular +** name and number of parameters exists. If no such function exists +** before this API is called, a new function is created.)^ ^The implementation +** of the new function always causes an exception to be thrown. So +** the new function is not good for anything by itself. Its only +** purpose is to be a placeholder function that can be overloaded +** by a [virtual table]. +*/ +int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); + +/* +** The interface to the virtual-table mechanism defined above (back up +** to a comment remarkably similar to this one) is currently considered +** to be experimental. The interface might change in incompatible ways. +** If this is a problem for you, do not use the interface at this time. +** +** When the virtual-table mechanism stabilizes, we will declare the +** interface fixed, support it indefinitely, and remove this comment. +*/ + +/* +** CAPI3REF: A Handle To An Open BLOB +** KEYWORDS: {BLOB handle} {BLOB handles} +** +** An instance of this object represents an open BLOB on which +** [sqlite3_blob_open | incremental BLOB I/O] can be performed. +** ^Objects of this type are created by [sqlite3_blob_open()] +** and destroyed by [sqlite3_blob_close()]. +** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces +** can be used to read or write small subsections of the BLOB. +** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. +*/ +typedef struct sqlite3_blob sqlite3_blob; + +/* +** CAPI3REF: Open A BLOB For Incremental I/O +** +** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located +** in row iRow, column zColumn, table zTable in database zDb; +** in other words, the same BLOB that would be selected by: +** +** <pre> +** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; +** </pre>)^ +** +** ^If the flags parameter is non-zero, then the BLOB is opened for read +** and write access. ^If it is zero, the BLOB is opened for read access. +** ^It is not possible to open a column that is part of an index or primary +** key for writing. ^If [foreign key constraints] are enabled, it is +** not possible to open a column that is part of a [child key] for writing. +** +** ^Note that the database name is not the filename that contains +** the database but rather the symbolic name of the database that +** appears after the AS keyword when the database is connected using [ATTACH]. +** ^For the main database file, the database name is "main". +** ^For TEMP tables, the database name is "temp". +** +** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written +** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set +** to be a null pointer.)^ +** ^This function sets the [database connection] error code and message +** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related +** functions. ^Note that the *ppBlob variable is always initialized in a +** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob +** regardless of the success or failure of this routine. +** +** ^(If the row that a BLOB handle points to is modified by an +** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects +** then the BLOB handle is marked as "expired". +** This is true if any column of the row is changed, even a column +** other than the one the BLOB handle is open on.)^ +** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for +** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. +** ^(Changes written into a BLOB prior to the BLOB expiring are not +** rolled back by the expiration of the BLOB. Such changes will eventually +** commit if the transaction continues to completion.)^ +** +** ^Use the [sqlite3_blob_bytes()] interface to determine the size of +** the opened blob. ^The size of a blob may not be changed by this +** interface. Use the [UPDATE] SQL command to change the size of a +** blob. +** +** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces +** and the built-in [zeroblob] SQL function can be used, if desired, +** to create an empty, zero-filled blob in which to read or write using +** this interface. +** +** To avoid a resource leak, every open [BLOB handle] should eventually +** be released by a call to [sqlite3_blob_close()]. +*/ +int sqlite3_blob_open( + sqlite3*, + const char *zDb, + const char *zTable, + const char *zColumn, + sqlite3_int64 iRow, + int flags, + sqlite3_blob **ppBlob +); + +/* +** CAPI3REF: Move a BLOB Handle to a New Row +** +** ^This function is used to move an existing blob handle so that it points +** to a different row of the same database table. ^The new row is identified +** by the rowid value passed as the second argument. Only the row can be +** changed. ^The database, table and column on which the blob handle is open +** remain the same. Moving an existing blob handle to a new row can be +** faster than closing the existing handle and opening a new one. +** +** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - +** it must exist and there must be either a blob or text value stored in +** the nominated column.)^ ^If the new row is not present in the table, or if +** it does not contain a blob or text value, or if another error occurs, an +** SQLite error code is returned and the blob handle is considered aborted. +** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or +** [sqlite3_blob_reopen()] on an aborted blob handle immediately return +** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle +** always returns zero. +** +** ^This function sets the database handle error code and message. +*/ +SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); + +/* +** CAPI3REF: Close A BLOB Handle +** +** ^Closes an open [BLOB handle]. +** +** ^Closing a BLOB shall cause the current transaction to commit +** if there are no other BLOBs, no pending prepared statements, and the +** database connection is in [autocommit mode]. +** ^If any writes were made to the BLOB, they might be held in cache +** until the close operation if they will fit. +** +** ^(Closing the BLOB often forces the changes +** out to disk and so if any I/O errors occur, they will likely occur +** at the time when the BLOB is closed. Any errors that occur during +** closing are reported as a non-zero return value.)^ +** +** ^(The BLOB is closed unconditionally. Even if this routine returns +** an error code, the BLOB is still closed.)^ +** +** ^Calling this routine with a null pointer (such as would be returned +** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. +*/ +int sqlite3_blob_close(sqlite3_blob *); + +/* +** CAPI3REF: Return The Size Of An Open BLOB +** +** ^Returns the size in bytes of the BLOB accessible via the +** successfully opened [BLOB handle] in its only argument. ^The +** incremental blob I/O routines can only read or overwriting existing +** blob content; they cannot change the size of a blob. +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +*/ +int sqlite3_blob_bytes(sqlite3_blob *); + +/* +** CAPI3REF: Read Data From A BLOB Incrementally +** +** ^(This function is used to read data from an open [BLOB handle] into a +** caller-supplied buffer. N bytes of data are copied into buffer Z +** from the open BLOB, starting at offset iOffset.)^ +** +** ^If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is +** less than zero, [SQLITE_ERROR] is returned and no data is read. +** ^The size of the blob (and hence the maximum value of N+iOffset) +** can be determined using the [sqlite3_blob_bytes()] interface. +** +** ^An attempt to read from an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. +** +** ^(On success, sqlite3_blob_read() returns SQLITE_OK. +** Otherwise, an [error code] or an [extended error code] is returned.)^ +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_write()]. +*/ +int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); + +/* +** CAPI3REF: Write Data Into A BLOB Incrementally +** +** ^This function is used to write data into an open [BLOB handle] from a +** caller-supplied buffer. ^N bytes of data are copied from the buffer Z +** into the open BLOB, starting at offset iOffset. +** +** ^If the [BLOB handle] passed as the first argument was not opened for +** writing (the flags parameter to [sqlite3_blob_open()] was zero), +** this function returns [SQLITE_READONLY]. +** +** ^This function may only modify the contents of the BLOB; it is +** not possible to increase the size of a BLOB using this API. +** ^If offset iOffset is less than N bytes from the end of the BLOB, +** [SQLITE_ERROR] is returned and no data is written. ^If N is +** less than zero [SQLITE_ERROR] is returned and no data is written. +** The size of the BLOB (and hence the maximum value of N+iOffset) +** can be determined using the [sqlite3_blob_bytes()] interface. +** +** ^An attempt to write to an expired [BLOB handle] fails with an +** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred +** before the [BLOB handle] expired are not rolled back by the +** expiration of the handle, though of course those changes might +** have been overwritten by the statement that expired the BLOB handle +** or by other independent statements. +** +** ^(On success, sqlite3_blob_write() returns SQLITE_OK. +** Otherwise, an [error code] or an [extended error code] is returned.)^ +** +** This routine only works on a [BLOB handle] which has been created +** by a prior successful call to [sqlite3_blob_open()] and which has not +** been closed by [sqlite3_blob_close()]. Passing any other pointer in +** to this routine results in undefined and probably undesirable behavior. +** +** See also: [sqlite3_blob_read()]. +*/ +int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); + +/* +** CAPI3REF: Virtual File System Objects +** +** A virtual filesystem (VFS) is an [sqlite3_vfs] object +** that SQLite uses to interact +** with the underlying operating system. Most SQLite builds come with a +** single default VFS that is appropriate for the host computer. +** New VFSes can be registered and existing VFSes can be unregistered. +** The following interfaces are provided. +** +** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. +** ^Names are case sensitive. +** ^Names are zero-terminated UTF-8 strings. +** ^If there is no match, a NULL pointer is returned. +** ^If zVfsName is NULL then the default VFS is returned. +** +** ^New VFSes are registered with sqlite3_vfs_register(). +** ^Each new VFS becomes the default VFS if the makeDflt flag is set. +** ^The same VFS can be registered multiple times without injury. +** ^To make an existing VFS into the default VFS, register it again +** with the makeDflt flag set. If two different VFSes with the +** same name are registered, the behavior is undefined. If a +** VFS is registered with a name that is NULL or an empty string, +** then the behavior is undefined. +** +** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. +** ^(If the default VFS is unregistered, another VFS is chosen as +** the default. The choice for the new VFS is arbitrary.)^ +*/ +sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); +int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); +int sqlite3_vfs_unregister(sqlite3_vfs*); + +/* +** CAPI3REF: Mutexes +** +** The SQLite core uses these routines for thread +** synchronization. Though they are intended for internal +** use by SQLite, code that links against SQLite is +** permitted to use any of these routines. +** +** The SQLite source code contains multiple implementations +** of these mutex routines. An appropriate implementation +** is selected automatically at compile-time. ^(The following +** implementations are available in the SQLite core: +** +** <ul> +** <li> SQLITE_MUTEX_OS2 +** <li> SQLITE_MUTEX_PTHREAD +** <li> SQLITE_MUTEX_W32 +** <li> SQLITE_MUTEX_NOOP +** </ul>)^ +** +** ^The SQLITE_MUTEX_NOOP implementation is a set of routines +** that does no real locking and is appropriate for use in +** a single-threaded application. ^The SQLITE_MUTEX_OS2, +** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations +** are appropriate for use on OS/2, Unix, and Windows. +** +** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor +** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex +** implementation is included with the library. In this case the +** application must supply a custom mutex implementation using the +** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function +** before calling sqlite3_initialize() or any other public sqlite3_ +** function that calls sqlite3_initialize().)^ +** +** ^The sqlite3_mutex_alloc() routine allocates a new +** mutex and returns a pointer to it. ^If it returns NULL +** that means that a mutex could not be allocated. ^SQLite +** will unwind its stack and return an error. ^(The argument +** to sqlite3_mutex_alloc() is one of these integer constants: +** +** <ul> +** <li> SQLITE_MUTEX_FAST +** <li> SQLITE_MUTEX_RECURSIVE +** <li> SQLITE_MUTEX_STATIC_MASTER +** <li> SQLITE_MUTEX_STATIC_MEM +** <li> SQLITE_MUTEX_STATIC_MEM2 +** <li> SQLITE_MUTEX_STATIC_PRNG +** <li> SQLITE_MUTEX_STATIC_LRU +** <li> SQLITE_MUTEX_STATIC_LRU2 +** </ul>)^ +** +** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) +** cause sqlite3_mutex_alloc() to create +** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE +** is used but not necessarily so when SQLITE_MUTEX_FAST is used. +** The mutex implementation does not need to make a distinction +** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does +** not want to. ^SQLite will only request a recursive mutex in +** cases where it really needs one. ^If a faster non-recursive mutex +** implementation is available on the host platform, the mutex subsystem +** might return such a mutex in response to SQLITE_MUTEX_FAST. +** +** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other +** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return +** a pointer to a static preexisting mutex. ^Six static mutexes are +** used by the current version of SQLite. Future versions of SQLite +** may add additional static mutexes. Static mutexes are for internal +** use by SQLite only. Applications that use SQLite mutexes should +** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or +** SQLITE_MUTEX_RECURSIVE. +** +** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST +** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() +** returns a different mutex on every call. ^But for the static +** mutex types, the same mutex is returned on every call that has +** the same type number. +** +** ^The sqlite3_mutex_free() routine deallocates a previously +** allocated dynamic mutex. ^SQLite is careful to deallocate every +** dynamic mutex that it allocates. The dynamic mutexes must not be in +** use when they are deallocated. Attempting to deallocate a static +** mutex results in undefined behavior. ^SQLite never deallocates +** a static mutex. +** +** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt +** to enter a mutex. ^If another thread is already within the mutex, +** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return +** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] +** upon successful entry. ^(Mutexes created using +** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. +** In such cases the, +** mutex must be exited an equal number of times before another thread +** can enter.)^ ^(If the same thread tries to enter any other +** kind of mutex more than once, the behavior is undefined. +** SQLite will never exhibit +** such behavior in its own use of mutexes.)^ +** +** ^(Some systems (for example, Windows 95) do not support the operation +** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() +** will always return SQLITE_BUSY. The SQLite core only ever uses +** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ +** +** ^The sqlite3_mutex_leave() routine exits a mutex that was +** previously entered by the same thread. ^(The behavior +** is undefined if the mutex is not currently entered by the +** calling thread or is not currently allocated. SQLite will +** never do either.)^ +** +** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or +** sqlite3_mutex_leave() is a NULL pointer, then all three routines +** behave as no-ops. +** +** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. +*/ +sqlite3_mutex *sqlite3_mutex_alloc(int); +void sqlite3_mutex_free(sqlite3_mutex*); +void sqlite3_mutex_enter(sqlite3_mutex*); +int sqlite3_mutex_try(sqlite3_mutex*); +void sqlite3_mutex_leave(sqlite3_mutex*); + +/* +** CAPI3REF: Mutex Methods Object +** +** An instance of this structure defines the low-level routines +** used to allocate and use mutexes. +** +** Usually, the default mutex implementations provided by SQLite are +** sufficient, however the user has the option of substituting a custom +** implementation for specialized deployments or systems for which SQLite +** does not provide a suitable implementation. In this case, the user +** creates and populates an instance of this structure to pass +** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. +** Additionally, an instance of this structure can be used as an +** output variable when querying the system for the current mutex +** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. +** +** ^The xMutexInit method defined by this structure is invoked as +** part of system initialization by the sqlite3_initialize() function. +** ^The xMutexInit routine is called by SQLite exactly once for each +** effective call to [sqlite3_initialize()]. +** +** ^The xMutexEnd method defined by this structure is invoked as +** part of system shutdown by the sqlite3_shutdown() function. The +** implementation of this method is expected to release all outstanding +** resources obtained by the mutex methods implementation, especially +** those obtained by the xMutexInit method. ^The xMutexEnd() +** interface is invoked exactly once for each call to [sqlite3_shutdown()]. +** +** ^(The remaining seven methods defined by this structure (xMutexAlloc, +** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and +** xMutexNotheld) implement the following interfaces (respectively): +** +** <ul> +** <li> [sqlite3_mutex_alloc()] </li> +** <li> [sqlite3_mutex_free()] </li> +** <li> [sqlite3_mutex_enter()] </li> +** <li> [sqlite3_mutex_try()] </li> +** <li> [sqlite3_mutex_leave()] </li> +** <li> [sqlite3_mutex_held()] </li> +** <li> [sqlite3_mutex_notheld()] </li> +** </ul>)^ +** +** The only difference is that the public sqlite3_XXX functions enumerated +** above silently ignore any invocations that pass a NULL pointer instead +** of a valid mutex handle. The implementations of the methods defined +** by this structure are not required to handle this case, the results +** of passing a NULL pointer instead of a valid mutex handle are undefined +** (i.e. it is acceptable to provide an implementation that segfaults if +** it is passed a NULL pointer). +** +** The xMutexInit() method must be threadsafe. ^It must be harmless to +** invoke xMutexInit() multiple times within the same process and without +** intervening calls to xMutexEnd(). Second and subsequent calls to +** xMutexInit() must be no-ops. +** +** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] +** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory +** allocation for a static mutex. ^However xMutexAlloc() may use SQLite +** memory allocation for a fast or recursive mutex. +** +** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is +** called, but only if the prior call to xMutexInit returned SQLITE_OK. +** If xMutexInit fails in any way, it is expected to clean up after itself +** prior to returning. +*/ +typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; +struct sqlite3_mutex_methods { + int (*xMutexInit)(void); + int (*xMutexEnd)(void); + sqlite3_mutex *(*xMutexAlloc)(int); + void (*xMutexFree)(sqlite3_mutex *); + void (*xMutexEnter)(sqlite3_mutex *); + int (*xMutexTry)(sqlite3_mutex *); + void (*xMutexLeave)(sqlite3_mutex *); + int (*xMutexHeld)(sqlite3_mutex *); + int (*xMutexNotheld)(sqlite3_mutex *); +}; + +/* +** CAPI3REF: Mutex Verification Routines +** +** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines +** are intended for use inside assert() statements. ^The SQLite core +** never uses these routines except inside an assert() and applications +** are advised to follow the lead of the core. ^The SQLite core only +** provides implementations for these routines when it is compiled +** with the SQLITE_DEBUG flag. ^External mutex implementations +** are only required to provide these routines if SQLITE_DEBUG is +** defined and if NDEBUG is not defined. +** +** ^These routines should return true if the mutex in their argument +** is held or not held, respectively, by the calling thread. +** +** ^The implementation is not required to provided versions of these +** routines that actually work. If the implementation does not provide working +** versions of these routines, it should at least provide stubs that always +** return true so that one does not get spurious assertion failures. +** +** ^If the argument to sqlite3_mutex_held() is a NULL pointer then +** the routine should return 1. This seems counter-intuitive since +** clearly the mutex cannot be held if it does not exist. But +** the reason the mutex does not exist is because the build is not +** using mutexes. And we do not want the assert() containing the +** call to sqlite3_mutex_held() to fail, so a non-zero return is +** the appropriate thing to do. ^The sqlite3_mutex_notheld() +** interface should also return 1 when given a NULL pointer. +*/ +#ifndef NDEBUG +int sqlite3_mutex_held(sqlite3_mutex*); +int sqlite3_mutex_notheld(sqlite3_mutex*); +#endif + +/* +** CAPI3REF: Mutex Types +** +** The [sqlite3_mutex_alloc()] interface takes a single argument +** which is one of these integer constants. +** +** The set of static mutexes may change from one SQLite release to the +** next. Applications that override the built-in mutex logic must be +** prepared to accommodate additional static mutexes. +*/ +#define SQLITE_MUTEX_FAST 0 +#define SQLITE_MUTEX_RECURSIVE 1 +#define SQLITE_MUTEX_STATIC_MASTER 2 +#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ +#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ +#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ +#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ +#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ +#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ + +/* +** CAPI3REF: Retrieve the mutex for a database connection +** +** ^This interface returns a pointer the [sqlite3_mutex] object that +** serializes access to the [database connection] given in the argument +** when the [threading mode] is Serialized. +** ^If the [threading mode] is Single-thread or Multi-thread then this +** routine returns a NULL pointer. +*/ +sqlite3_mutex *sqlite3_db_mutex(sqlite3*); + +/* +** CAPI3REF: Low-Level Control Of Database Files +** +** ^The [sqlite3_file_control()] interface makes a direct call to the +** xFileControl method for the [sqlite3_io_methods] object associated +** with a particular database identified by the second argument. ^The +** name of the database is "main" for the main database or "temp" for the +** TEMP database, or the name that appears after the AS keyword for +** databases that are added using the [ATTACH] SQL command. +** ^A NULL pointer can be used in place of "main" to refer to the +** main database file. +** ^The third and fourth parameters to this routine +** are passed directly through to the second and third parameters of +** the xFileControl method. ^The return value of the xFileControl +** method becomes the return value of this routine. +** +** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes +** a pointer to the underlying [sqlite3_file] object to be written into +** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER +** case is a short-circuit path which does not actually invoke the +** underlying sqlite3_io_methods.xFileControl method. +** +** ^If the second parameter (zDbName) does not match the name of any +** open database file, then SQLITE_ERROR is returned. ^This error +** code is not remembered and will not be recalled by [sqlite3_errcode()] +** or [sqlite3_errmsg()]. The underlying xFileControl method might +** also return SQLITE_ERROR. There is no way to distinguish between +** an incorrect zDbName and an SQLITE_ERROR return from the underlying +** xFileControl method. +** +** See also: [SQLITE_FCNTL_LOCKSTATE] +*/ +int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); + +/* +** CAPI3REF: Testing Interface +** +** ^The sqlite3_test_control() interface is used to read out internal +** state of SQLite and to inject faults into SQLite for testing +** purposes. ^The first parameter is an operation code that determines +** the number, meaning, and operation of all subsequent parameters. +** +** This interface is not for use by applications. It exists solely +** for verifying the correct operation of the SQLite library. Depending +** on how the SQLite library is compiled, this interface might not exist. +** +** The details of the operation codes, their meanings, the parameters +** they take, and what they do are all subject to change without notice. +** Unlike most of the SQLite API, this function is not guaranteed to +** operate consistently from one release to the next. +*/ +int sqlite3_test_control(int op, ...); + +/* +** CAPI3REF: Testing Interface Operation Codes +** +** These constants are the valid operation code parameters used +** as the first argument to [sqlite3_test_control()]. +** +** These parameters and their meanings are subject to change +** without notice. These values are for testing purposes only. +** Applications should not use any of these parameters or the +** [sqlite3_test_control()] interface. +*/ +#define SQLITE_TESTCTRL_FIRST 5 +#define SQLITE_TESTCTRL_PRNG_SAVE 5 +#define SQLITE_TESTCTRL_PRNG_RESTORE 6 +#define SQLITE_TESTCTRL_PRNG_RESET 7 +#define SQLITE_TESTCTRL_BITVEC_TEST 8 +#define SQLITE_TESTCTRL_FAULT_INSTALL 9 +#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 +#define SQLITE_TESTCTRL_PENDING_BYTE 11 +#define SQLITE_TESTCTRL_ASSERT 12 +#define SQLITE_TESTCTRL_ALWAYS 13 +#define SQLITE_TESTCTRL_RESERVE 14 +#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 +#define SQLITE_TESTCTRL_ISKEYWORD 16 +#define SQLITE_TESTCTRL_PGHDRSZ 17 +#define SQLITE_TESTCTRL_SCRATCHMALLOC 18 +#define SQLITE_TESTCTRL_LOCALTIME_FAULT 19 +#define SQLITE_TESTCTRL_LAST 19 + +/* +** CAPI3REF: SQLite Runtime Status +** +** ^This interface is used to retrieve runtime status information +** about the performance of SQLite, and optionally to reset various +** highwater marks. ^The first argument is an integer code for +** the specific parameter to measure. ^(Recognized integer codes +** are of the form [status parameters | SQLITE_STATUS_...].)^ +** ^The current value of the parameter is returned into *pCurrent. +** ^The highest recorded value is returned in *pHighwater. ^If the +** resetFlag is true, then the highest record value is reset after +** *pHighwater is written. ^(Some parameters do not record the highest +** value. For those parameters +** nothing is written into *pHighwater and the resetFlag is ignored.)^ +** ^(Other parameters record only the highwater mark and not the current +** value. For these latter parameters nothing is written into *pCurrent.)^ +** +** ^The sqlite3_status() routine returns SQLITE_OK on success and a +** non-zero [error code] on failure. +** +** This routine is threadsafe but is not atomic. This routine can be +** called while other threads are running the same or different SQLite +** interfaces. However the values returned in *pCurrent and +** *pHighwater reflect the status of SQLite at different points in time +** and it is possible that another thread might change the parameter +** in between the times when *pCurrent and *pHighwater are written. +** +** See also: [sqlite3_db_status()] +*/ +int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); + + +/* +** CAPI3REF: Status Parameters +** KEYWORDS: {status parameters} +** +** These integer constants designate various run-time status parameters +** that can be returned by [sqlite3_status()]. +** +** <dl> +** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> +** <dd>This parameter is the current amount of memory checked out +** using [sqlite3_malloc()], either directly or indirectly. The +** figure includes calls made to [sqlite3_malloc()] by the application +** and internal memory usage by the SQLite library. Scratch memory +** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache +** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in +** this parameter. The amount returned is the sum of the allocation +** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ +** +** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their +** internal equivalents). Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd>)^ +** +** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> +** <dd>This parameter records the number of separate memory allocations +** currently checked out.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> +** <dd>This parameter returns the number of pages used out of the +** [pagecache memory allocator] that was configured using +** [SQLITE_CONFIG_PAGECACHE]. The +** value returned is in pages, not in bytes.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] +** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> +** <dd>This parameter returns the number of bytes of page cache +** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] +** buffer and where forced to overflow to [sqlite3_malloc()]. The +** returned value includes allocations that overflowed because they +** where too large (they were larger than the "sz" parameter to +** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because +** no space was left in the page cache.</dd>)^ +** +** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [pagecache memory allocator]. Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd>)^ +** +** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> +** <dd>This parameter returns the number of allocations used out of the +** [scratch memory allocator] configured using +** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not +** in bytes. Since a single thread may only have one scratch allocation +** outstanding at time, this parameter also reports the number of threads +** using scratch memory at the same time.</dd>)^ +** +** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> +** <dd>This parameter returns the number of bytes of scratch memory +** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] +** buffer and where forced to overflow to [sqlite3_malloc()]. The values +** returned include overflows because the requested allocation was too +** larger (that is, because the requested allocation was larger than the +** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer +** slots were available. +** </dd>)^ +** +** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> +** <dd>This parameter records the largest memory allocation request +** handed to [scratch memory allocator]. Only the value returned in the +** *pHighwater parameter to [sqlite3_status()] is of interest. +** The value written into the *pCurrent parameter is undefined.</dd>)^ +** +** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> +** <dd>This parameter records the deepest parser stack. It is only +** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ +** </dl> +** +** New status parameters may be added from time to time. +*/ +#define SQLITE_STATUS_MEMORY_USED 0 +#define SQLITE_STATUS_PAGECACHE_USED 1 +#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 +#define SQLITE_STATUS_SCRATCH_USED 3 +#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 +#define SQLITE_STATUS_MALLOC_SIZE 5 +#define SQLITE_STATUS_PARSER_STACK 6 +#define SQLITE_STATUS_PAGECACHE_SIZE 7 +#define SQLITE_STATUS_SCRATCH_SIZE 8 +#define SQLITE_STATUS_MALLOC_COUNT 9 + +/* +** CAPI3REF: Database Connection Status +** +** ^This interface is used to retrieve runtime status information +** about a single [database connection]. ^The first argument is the +** database connection object to be interrogated. ^The second argument +** is an integer constant, taken from the set of +** [SQLITE_DBSTATUS options], that +** determines the parameter to interrogate. The set of +** [SQLITE_DBSTATUS options] is likely +** to grow in future releases of SQLite. +** +** ^The current value of the requested parameter is written into *pCur +** and the highest instantaneous value is written into *pHiwtr. ^If +** the resetFlg is true, then the highest instantaneous value is +** reset back down to the current value. +** +** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a +** non-zero [error code] on failure. +** +** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. +*/ +int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); + +/* +** CAPI3REF: Status Parameters for database connections +** KEYWORDS: {SQLITE_DBSTATUS options} +** +** These constants are the available integer "verbs" that can be passed as +** the second argument to the [sqlite3_db_status()] interface. +** +** New verbs may be added in future releases of SQLite. Existing verbs +** might be discontinued. Applications should check the return code from +** [sqlite3_db_status()] to make sure that the call worked. +** The [sqlite3_db_status()] interface will return a non-zero error code +** if a discontinued or unsupported verb is invoked. +** +** <dl> +** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> +** <dd>This parameter returns the number of lookaside memory slots currently +** checked out.</dd>)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> +** <dd>This parameter returns the number malloc attempts that were +** satisfied using lookaside memory. Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] +** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> +** <dd>This parameter returns the number malloc attempts that might have +** been satisfied using lookaside memory but failed due to the amount of +** memory requested being larger than the lookaside slot size. +** Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] +** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> +** <dd>This parameter returns the number malloc attempts that might have +** been satisfied using lookaside memory but failed due to all lookaside +** memory already being in use. +** Only the high-water value is meaningful; +** the current value is always zero.)^ +** +** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> +** <dd>This parameter returns the approximate number of of bytes of heap +** memory used by all pager caches associated with the database connection.)^ +** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. +** +** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> +** <dd>This parameter returns the approximate number of of bytes of heap +** memory used to store the schema for all databases associated +** with the connection - main, temp, and any [ATTACH]-ed databases.)^ +** ^The full amount of memory used by the schemas is reported, even if the +** schema memory is shared with other database connections due to +** [shared cache mode] being enabled. +** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. +** +** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> +** <dd>This parameter returns the approximate number of of bytes of heap +** and lookaside memory used by all prepared statements associated with +** the database connection.)^ +** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> +** <dd>This parameter returns the number of pager cache hits that have +** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT +** is always 0. +** </dd> +** +** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> +** <dd>This parameter returns the number of pager cache misses that have +** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS +** is always 0. +** </dd> +** </dl> +*/ +#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 +#define SQLITE_DBSTATUS_CACHE_USED 1 +#define SQLITE_DBSTATUS_SCHEMA_USED 2 +#define SQLITE_DBSTATUS_STMT_USED 3 +#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 +#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 +#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 +#define SQLITE_DBSTATUS_CACHE_HIT 7 +#define SQLITE_DBSTATUS_CACHE_MISS 8 +#define SQLITE_DBSTATUS_MAX 8 /* Largest defined DBSTATUS */ + + +/* +** CAPI3REF: Prepared Statement Status +** +** ^(Each prepared statement maintains various +** [SQLITE_STMTSTATUS counters] that measure the number +** of times it has performed specific operations.)^ These counters can +** be used to monitor the performance characteristics of the prepared +** statements. For example, if the number of table steps greatly exceeds +** the number of table searches or result rows, that would tend to indicate +** that the prepared statement is using a full table scan rather than +** an index. +** +** ^(This interface is used to retrieve and reset counter values from +** a [prepared statement]. The first argument is the prepared statement +** object to be interrogated. The second argument +** is an integer code for a specific [SQLITE_STMTSTATUS counter] +** to be interrogated.)^ +** ^The current value of the requested counter is returned. +** ^If the resetFlg is true, then the counter is reset to zero after this +** interface call returns. +** +** See also: [sqlite3_status()] and [sqlite3_db_status()]. +*/ +int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); + +/* +** CAPI3REF: Status Parameters for prepared statements +** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} +** +** These preprocessor macros define integer codes that name counter +** values associated with the [sqlite3_stmt_status()] interface. +** The meanings of the various counters are as follows: +** +** <dl> +** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> +** <dd>^This is the number of times that SQLite has stepped forward in +** a table as part of a full table scan. Large numbers for this counter +** may indicate opportunities for performance improvement through +** careful use of indices.</dd> +** +** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> +** <dd>^This is the number of sort operations that have occurred. +** A non-zero value in this counter may indicate an opportunity to +** improvement performance through careful use of indices.</dd> +** +** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> +** <dd>^This is the number of rows inserted into transient indices that +** were created automatically in order to help joins run faster. +** A non-zero value in this counter may indicate an opportunity to +** improvement performance by adding permanent indices that do not +** need to be reinitialized each time the statement is run.</dd> +** </dl> +*/ +#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 +#define SQLITE_STMTSTATUS_SORT 2 +#define SQLITE_STMTSTATUS_AUTOINDEX 3 + +/* +** CAPI3REF: Custom Page Cache Object +** +** The sqlite3_pcache type is opaque. It is implemented by +** the pluggable module. The SQLite core has no knowledge of +** its size or internal structure and never deals with the +** sqlite3_pcache object except by holding and passing pointers +** to the object. +** +** See [sqlite3_pcache_methods] for additional information. +*/ +typedef struct sqlite3_pcache sqlite3_pcache; + +/* +** CAPI3REF: Application Defined Page Cache. +** KEYWORDS: {page cache} +** +** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can +** register an alternative page cache implementation by passing in an +** instance of the sqlite3_pcache_methods structure.)^ +** In many applications, most of the heap memory allocated by +** SQLite is used for the page cache. +** By implementing a +** custom page cache using this API, an application can better control +** the amount of memory consumed by SQLite, the way in which +** that memory is allocated and released, and the policies used to +** determine exactly which parts of a database file are cached and for +** how long. +** +** The alternative page cache mechanism is an +** extreme measure that is only needed by the most demanding applications. +** The built-in page cache is recommended for most uses. +** +** ^(The contents of the sqlite3_pcache_methods structure are copied to an +** internal buffer by SQLite within the call to [sqlite3_config]. Hence +** the application may discard the parameter after the call to +** [sqlite3_config()] returns.)^ +** +** [[the xInit() page cache method]] +** ^(The xInit() method is called once for each effective +** call to [sqlite3_initialize()])^ +** (usually only once during the lifetime of the process). ^(The xInit() +** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ +** The intent of the xInit() method is to set up global data structures +** required by the custom page cache implementation. +** ^(If the xInit() method is NULL, then the +** built-in default page cache is used instead of the application defined +** page cache.)^ +** +** [[the xShutdown() page cache method]] +** ^The xShutdown() method is called by [sqlite3_shutdown()]. +** It can be used to clean up +** any outstanding resources before process shutdown, if required. +** ^The xShutdown() method may be NULL. +** +** ^SQLite automatically serializes calls to the xInit method, +** so the xInit method need not be threadsafe. ^The +** xShutdown method is only called from [sqlite3_shutdown()] so it does +** not need to be threadsafe either. All other methods must be threadsafe +** in multithreaded applications. +** +** ^SQLite will never invoke xInit() more than once without an intervening +** call to xShutdown(). +** +** [[the xCreate() page cache methods]] +** ^SQLite invokes the xCreate() method to construct a new cache instance. +** SQLite will typically create one cache instance for each open database file, +** though this is not guaranteed. ^The +** first parameter, szPage, is the size in bytes of the pages that must +** be allocated by the cache. ^szPage will not be a power of two. ^szPage +** will the page size of the database file that is to be cached plus an +** increment (here called "R") of less than 250. SQLite will use the +** extra R bytes on each page to store metadata about the underlying +** database page on disk. The value of R depends +** on the SQLite version, the target platform, and how SQLite was compiled. +** ^(R is constant for a particular build of SQLite. Except, there are two +** distinct values of R when SQLite is compiled with the proprietary +** ZIPVFS extension.)^ ^The second argument to +** xCreate(), bPurgeable, is true if the cache being created will +** be used to cache database pages of a file stored on disk, or +** false if it is used for an in-memory database. The cache implementation +** does not have to do anything special based with the value of bPurgeable; +** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will +** never invoke xUnpin() except to deliberately delete a page. +** ^In other words, calls to xUnpin() on a cache with bPurgeable set to +** false will always have the "discard" flag set to true. +** ^Hence, a cache created with bPurgeable false will +** never contain any unpinned pages. +** +** [[the xCachesize() page cache method]] +** ^(The xCachesize() method may be called at any time by SQLite to set the +** suggested maximum cache-size (number of pages stored by) the cache +** instance passed as the first argument. This is the value configured using +** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable +** parameter, the implementation is not required to do anything with this +** value; it is advisory only. +** +** [[the xPagecount() page cache methods]] +** The xPagecount() method must return the number of pages currently +** stored in the cache, both pinned and unpinned. +** +** [[the xFetch() page cache methods]] +** The xFetch() method locates a page in the cache and returns a pointer to +** the page, or a NULL pointer. +** A "page", in this context, means a buffer of szPage bytes aligned at an +** 8-byte boundary. The page to be fetched is determined by the key. ^The +** minimum key value is 1. After it has been retrieved using xFetch, the page +** is considered to be "pinned". +** +** If the requested page is already in the page cache, then the page cache +** implementation must return a pointer to the page buffer with its content +** intact. If the requested page is not already in the cache, then the +** cache implementation should use the value of the createFlag +** parameter to help it determined what action to take: +** +** <table border=1 width=85% align=center> +** <tr><th> createFlag <th> Behaviour when page is not already in cache +** <tr><td> 0 <td> Do not allocate a new page. Return NULL. +** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. +** Otherwise return NULL. +** <tr><td> 2 <td> Make every effort to allocate a new page. Only return +** NULL if allocating a new page is effectively impossible. +** </table> +** +** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite +** will only use a createFlag of 2 after a prior call with a createFlag of 1 +** failed.)^ In between the to xFetch() calls, SQLite may +** attempt to unpin one or more cache pages by spilling the content of +** pinned pages to disk and synching the operating system disk cache. +** +** [[the xUnpin() page cache method]] +** ^xUnpin() is called by SQLite with a pointer to a currently pinned page +** as its second argument. If the third parameter, discard, is non-zero, +** then the page must be evicted from the cache. +** ^If the discard parameter is +** zero, then the page may be discarded or retained at the discretion of +** page cache implementation. ^The page cache implementation +** may choose to evict unpinned pages at any time. +** +** The cache must not perform any reference counting. A single +** call to xUnpin() unpins the page regardless of the number of prior calls +** to xFetch(). +** +** [[the xRekey() page cache methods]] +** The xRekey() method is used to change the key value associated with the +** page passed as the second argument. If the cache +** previously contains an entry associated with newKey, it must be +** discarded. ^Any prior cache entry associated with newKey is guaranteed not +** to be pinned. +** +** When SQLite calls the xTruncate() method, the cache must discard all +** existing cache entries with page numbers (keys) greater than or equal +** to the value of the iLimit parameter passed to xTruncate(). If any +** of these pages are pinned, they are implicitly unpinned, meaning that +** they can be safely discarded. +** +** [[the xDestroy() page cache method]] +** ^The xDestroy() method is used to delete a cache allocated by xCreate(). +** All resources associated with the specified cache should be freed. ^After +** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] +** handle invalid, and will not use it with any other sqlite3_pcache_methods +** functions. +*/ +typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; +struct sqlite3_pcache_methods { + void *pArg; + int (*xInit)(void*); + void (*xShutdown)(void*); + sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); + void (*xCachesize)(sqlite3_pcache*, int nCachesize); + int (*xPagecount)(sqlite3_pcache*); + void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); + void (*xUnpin)(sqlite3_pcache*, void*, int discard); + void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); + void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); + void (*xDestroy)(sqlite3_pcache*); +}; + +/* +** CAPI3REF: Online Backup Object +** +** The sqlite3_backup object records state information about an ongoing +** online backup operation. ^The sqlite3_backup object is created by +** a call to [sqlite3_backup_init()] and is destroyed by a call to +** [sqlite3_backup_finish()]. +** +** See Also: [Using the SQLite Online Backup API] +*/ +typedef struct sqlite3_backup sqlite3_backup; + +/* +** CAPI3REF: Online Backup API. +** +** The backup API copies the content of one database into another. +** It is useful either for creating backups of databases or +** for copying in-memory databases to or from persistent files. +** +** See Also: [Using the SQLite Online Backup API] +** +** ^SQLite holds a write transaction open on the destination database file +** for the duration of the backup operation. +** ^The source database is read-locked only while it is being read; +** it is not locked continuously for the entire backup operation. +** ^Thus, the backup may be performed on a live source database without +** preventing other database connections from +** reading or writing to the source database while the backup is underway. +** +** ^(To perform a backup operation: +** <ol> +** <li><b>sqlite3_backup_init()</b> is called once to initialize the +** backup, +** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer +** the data between the two databases, and finally +** <li><b>sqlite3_backup_finish()</b> is called to release all resources +** associated with the backup operation. +** </ol>)^ +** There should be exactly one call to sqlite3_backup_finish() for each +** successful call to sqlite3_backup_init(). +** +** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> +** +** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the +** [database connection] associated with the destination database +** and the database name, respectively. +** ^The database name is "main" for the main database, "temp" for the +** temporary database, or the name specified after the AS keyword in +** an [ATTACH] statement for an attached database. +** ^The S and M arguments passed to +** sqlite3_backup_init(D,N,S,M) identify the [database connection] +** and database name of the source database, respectively. +** ^The source and destination [database connections] (parameters S and D) +** must be different or else sqlite3_backup_init(D,N,S,M) will fail with +** an error. +** +** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is +** returned and an error code and error message are stored in the +** destination [database connection] D. +** ^The error code and message for the failed call to sqlite3_backup_init() +** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or +** [sqlite3_errmsg16()] functions. +** ^A successful call to sqlite3_backup_init() returns a pointer to an +** [sqlite3_backup] object. +** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and +** sqlite3_backup_finish() functions to perform the specified backup +** operation. +** +** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> +** +** ^Function sqlite3_backup_step(B,N) will copy up to N pages between +** the source and destination databases specified by [sqlite3_backup] object B. +** ^If N is negative, all remaining source pages are copied. +** ^If sqlite3_backup_step(B,N) successfully copies N pages and there +** are still more pages to be copied, then the function returns [SQLITE_OK]. +** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages +** from source to destination, then it returns [SQLITE_DONE]. +** ^If an error occurs while running sqlite3_backup_step(B,N), +** then an [error code] is returned. ^As well as [SQLITE_OK] and +** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], +** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. +** +** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if +** <ol> +** <li> the destination database was opened read-only, or +** <li> the destination database is using write-ahead-log journaling +** and the destination and source page sizes differ, or +** <li> the destination database is an in-memory database and the +** destination and source page sizes differ. +** </ol>)^ +** +** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then +** the [sqlite3_busy_handler | busy-handler function] +** is invoked (if one is specified). ^If the +** busy-handler returns non-zero before the lock is available, then +** [SQLITE_BUSY] is returned to the caller. ^In this case the call to +** sqlite3_backup_step() can be retried later. ^If the source +** [database connection] +** is being used to write to the source database when sqlite3_backup_step() +** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this +** case the call to sqlite3_backup_step() can be retried later on. ^(If +** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or +** [SQLITE_READONLY] is returned, then +** there is no point in retrying the call to sqlite3_backup_step(). These +** errors are considered fatal.)^ The application must accept +** that the backup operation has failed and pass the backup operation handle +** to the sqlite3_backup_finish() to release associated resources. +** +** ^The first call to sqlite3_backup_step() obtains an exclusive lock +** on the destination file. ^The exclusive lock is not released until either +** sqlite3_backup_finish() is called or the backup operation is complete +** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to +** sqlite3_backup_step() obtains a [shared lock] on the source database that +** lasts for the duration of the sqlite3_backup_step() call. +** ^Because the source database is not locked between calls to +** sqlite3_backup_step(), the source database may be modified mid-way +** through the backup process. ^If the source database is modified by an +** external process or via a database connection other than the one being +** used by the backup operation, then the backup will be automatically +** restarted by the next call to sqlite3_backup_step(). ^If the source +** database is modified by the using the same database connection as is used +** by the backup operation, then the backup database is automatically +** updated at the same time. +** +** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> +** +** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the +** application wishes to abandon the backup operation, the application +** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). +** ^The sqlite3_backup_finish() interfaces releases all +** resources associated with the [sqlite3_backup] object. +** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any +** active write-transaction on the destination database is rolled back. +** The [sqlite3_backup] object is invalid +** and may not be used following a call to sqlite3_backup_finish(). +** +** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no +** sqlite3_backup_step() errors occurred, regardless or whether or not +** sqlite3_backup_step() completed. +** ^If an out-of-memory condition or IO error occurred during any prior +** sqlite3_backup_step() call on the same [sqlite3_backup] object, then +** sqlite3_backup_finish() returns the corresponding [error code]. +** +** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() +** is not a permanent error and does not affect the return value of +** sqlite3_backup_finish(). +** +** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] +** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> +** +** ^Each call to sqlite3_backup_step() sets two values inside +** the [sqlite3_backup] object: the number of pages still to be backed +** up and the total number of pages in the source database file. +** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces +** retrieve these two values, respectively. +** +** ^The values returned by these functions are only updated by +** sqlite3_backup_step(). ^If the source database is modified during a backup +** operation, then the values are not updated to account for any extra +** pages that need to be updated or the size of the source database file +** changing. +** +** <b>Concurrent Usage of Database Handles</b> +** +** ^The source [database connection] may be used by the application for other +** purposes while a backup operation is underway or being initialized. +** ^If SQLite is compiled and configured to support threadsafe database +** connections, then the source database connection may be used concurrently +** from within other threads. +** +** However, the application must guarantee that the destination +** [database connection] is not passed to any other API (by any thread) after +** sqlite3_backup_init() is called and before the corresponding call to +** sqlite3_backup_finish(). SQLite does not currently check to see +** if the application incorrectly accesses the destination [database connection] +** and so no error code is reported, but the operations may malfunction +** nevertheless. Use of the destination database connection while a +** backup is in progress might also also cause a mutex deadlock. +** +** If running in [shared cache mode], the application must +** guarantee that the shared cache used by the destination database +** is not accessed while the backup is running. In practice this means +** that the application must guarantee that the disk file being +** backed up to is not accessed by any connection within the process, +** not just the specific connection that was passed to sqlite3_backup_init(). +** +** The [sqlite3_backup] object itself is partially threadsafe. Multiple +** threads may safely make multiple concurrent calls to sqlite3_backup_step(). +** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() +** APIs are not strictly speaking threadsafe. If they are invoked at the +** same time as another thread is invoking sqlite3_backup_step() it is +** possible that they return invalid values. +*/ +sqlite3_backup *sqlite3_backup_init( + sqlite3 *pDest, /* Destination database handle */ + const char *zDestName, /* Destination database name */ + sqlite3 *pSource, /* Source database handle */ + const char *zSourceName /* Source database name */ +); +int sqlite3_backup_step(sqlite3_backup *p, int nPage); +int sqlite3_backup_finish(sqlite3_backup *p); +int sqlite3_backup_remaining(sqlite3_backup *p); +int sqlite3_backup_pagecount(sqlite3_backup *p); + +/* +** CAPI3REF: Unlock Notification +** +** ^When running in shared-cache mode, a database operation may fail with +** an [SQLITE_LOCKED] error if the required locks on the shared-cache or +** individual tables within the shared-cache cannot be obtained. See +** [SQLite Shared-Cache Mode] for a description of shared-cache locking. +** ^This API may be used to register a callback that SQLite will invoke +** when the connection currently holding the required lock relinquishes it. +** ^This API is only available if the library was compiled with the +** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. +** +** See Also: [Using the SQLite Unlock Notification Feature]. +** +** ^Shared-cache locks are released when a database connection concludes +** its current transaction, either by committing it or rolling it back. +** +** ^When a connection (known as the blocked connection) fails to obtain a +** shared-cache lock and SQLITE_LOCKED is returned to the caller, the +** identity of the database connection (the blocking connection) that +** has locked the required resource is stored internally. ^After an +** application receives an SQLITE_LOCKED error, it may call the +** sqlite3_unlock_notify() method with the blocked connection handle as +** the first argument to register for a callback that will be invoked +** when the blocking connections current transaction is concluded. ^The +** callback is invoked from within the [sqlite3_step] or [sqlite3_close] +** call that concludes the blocking connections transaction. +** +** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, +** there is a chance that the blocking connection will have already +** concluded its transaction by the time sqlite3_unlock_notify() is invoked. +** If this happens, then the specified callback is invoked immediately, +** from within the call to sqlite3_unlock_notify().)^ +** +** ^If the blocked connection is attempting to obtain a write-lock on a +** shared-cache table, and more than one other connection currently holds +** a read-lock on the same table, then SQLite arbitrarily selects one of +** the other connections to use as the blocking connection. +** +** ^(There may be at most one unlock-notify callback registered by a +** blocked connection. If sqlite3_unlock_notify() is called when the +** blocked connection already has a registered unlock-notify callback, +** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is +** called with a NULL pointer as its second argument, then any existing +** unlock-notify callback is canceled. ^The blocked connections +** unlock-notify callback may also be canceled by closing the blocked +** connection using [sqlite3_close()]. +** +** The unlock-notify callback is not reentrant. If an application invokes +** any sqlite3_xxx API functions from within an unlock-notify callback, a +** crash or deadlock may be the result. +** +** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always +** returns SQLITE_OK. +** +** <b>Callback Invocation Details</b> +** +** When an unlock-notify callback is registered, the application provides a +** single void* pointer that is passed to the callback when it is invoked. +** However, the signature of the callback function allows SQLite to pass +** it an array of void* context pointers. The first argument passed to +** an unlock-notify callback is a pointer to an array of void* pointers, +** and the second is the number of entries in the array. +** +** When a blocking connections transaction is concluded, there may be +** more than one blocked connection that has registered for an unlock-notify +** callback. ^If two or more such blocked connections have specified the +** same callback function, then instead of invoking the callback function +** multiple times, it is invoked once with the set of void* context pointers +** specified by the blocked connections bundled together into an array. +** This gives the application an opportunity to prioritize any actions +** related to the set of unblocked database connections. +** +** <b>Deadlock Detection</b> +** +** Assuming that after registering for an unlock-notify callback a +** database waits for the callback to be issued before taking any further +** action (a reasonable assumption), then using this API may cause the +** application to deadlock. For example, if connection X is waiting for +** connection Y's transaction to be concluded, and similarly connection +** Y is waiting on connection X's transaction, then neither connection +** will proceed and the system may remain deadlocked indefinitely. +** +** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock +** detection. ^If a given call to sqlite3_unlock_notify() would put the +** system in a deadlocked state, then SQLITE_LOCKED is returned and no +** unlock-notify callback is registered. The system is said to be in +** a deadlocked state if connection A has registered for an unlock-notify +** callback on the conclusion of connection B's transaction, and connection +** B has itself registered for an unlock-notify callback when connection +** A's transaction is concluded. ^Indirect deadlock is also detected, so +** the system is also considered to be deadlocked if connection B has +** registered for an unlock-notify callback on the conclusion of connection +** C's transaction, where connection C is waiting on connection A. ^Any +** number of levels of indirection are allowed. +** +** <b>The "DROP TABLE" Exception</b> +** +** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost +** always appropriate to call sqlite3_unlock_notify(). There is however, +** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, +** SQLite checks if there are any currently executing SELECT statements +** that belong to the same connection. If there are, SQLITE_LOCKED is +** returned. In this case there is no "blocking connection", so invoking +** sqlite3_unlock_notify() results in the unlock-notify callback being +** invoked immediately. If the application then re-attempts the "DROP TABLE" +** or "DROP INDEX" query, an infinite loop might be the result. +** +** One way around this problem is to check the extended error code returned +** by an sqlite3_step() call. ^(If there is a blocking connection, then the +** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in +** the special "DROP TABLE/INDEX" case, the extended error code is just +** SQLITE_LOCKED.)^ +*/ +int sqlite3_unlock_notify( + sqlite3 *pBlocked, /* Waiting connection */ + void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ + void *pNotifyArg /* Argument to pass to xNotify */ +); + + +/* +** CAPI3REF: String Comparison +** +** ^The [sqlite3_strnicmp()] API allows applications and extensions to +** compare the contents of two buffers containing UTF-8 strings in a +** case-independent fashion, using the same definition of case independence +** that SQLite uses internally when comparing identifiers. +*/ +int sqlite3_strnicmp(const char *, const char *, int); + +/* +** CAPI3REF: Error Logging Interface +** +** ^The [sqlite3_log()] interface writes a message into the error log +** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. +** ^If logging is enabled, the zFormat string and subsequent arguments are +** used with [sqlite3_snprintf()] to generate the final output string. +** +** The sqlite3_log() interface is intended for use by extensions such as +** virtual tables, collating functions, and SQL functions. While there is +** nothing to prevent an application from calling sqlite3_log(), doing so +** is considered bad form. +** +** The zFormat string must not be NULL. +** +** To avoid deadlocks and other threading problems, the sqlite3_log() routine +** will not use dynamically allocated memory. The log message is stored in +** a fixed-length buffer on the stack. If the log message is longer than +** a few hundred characters, it will be truncated to the length of the +** buffer. +*/ +void sqlite3_log(int iErrCode, const char *zFormat, ...); + +/* +** CAPI3REF: Write-Ahead Log Commit Hook +** +** ^The [sqlite3_wal_hook()] function is used to register a callback that +** will be invoked each time a database connection commits data to a +** [write-ahead log] (i.e. whenever a transaction is committed in +** [journal_mode | journal_mode=WAL mode]). +** +** ^The callback is invoked by SQLite after the commit has taken place and +** the associated write-lock on the database released, so the implementation +** may read, write or [checkpoint] the database as required. +** +** ^The first parameter passed to the callback function when it is invoked +** is a copy of the third parameter passed to sqlite3_wal_hook() when +** registering the callback. ^The second is a copy of the database handle. +** ^The third parameter is the name of the database that was written to - +** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter +** is the number of pages currently in the write-ahead log file, +** including those that were just committed. +** +** The callback function should normally return [SQLITE_OK]. ^If an error +** code is returned, that error will propagate back up through the +** SQLite code base to cause the statement that provoked the callback +** to report an error, though the commit will have still occurred. If the +** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value +** that does not correspond to any valid SQLite error code, the results +** are undefined. +** +** A single database handle may have at most a single write-ahead log callback +** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any +** previously registered write-ahead log callback. ^Note that the +** [sqlite3_wal_autocheckpoint()] interface and the +** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will +** those overwrite any prior [sqlite3_wal_hook()] settings. +*/ +void *sqlite3_wal_hook( + sqlite3*, + int(*)(void *,sqlite3*,const char*,int), + void* +); + +/* +** CAPI3REF: Configure an auto-checkpoint +** +** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around +** [sqlite3_wal_hook()] that causes any database on [database connection] D +** to automatically [checkpoint] +** after committing a transaction if there are N or +** more frames in the [write-ahead log] file. ^Passing zero or +** a negative value as the nFrame parameter disables automatic +** checkpoints entirely. +** +** ^The callback registered by this function replaces any existing callback +** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback +** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism +** configured by this function. +** +** ^The [wal_autocheckpoint pragma] can be used to invoke this interface +** from SQL. +** +** ^Every new [database connection] defaults to having the auto-checkpoint +** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] +** pages. The use of this interface +** is only necessary if the default setting is found to be suboptimal +** for a particular application. +*/ +int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); + +/* +** CAPI3REF: Checkpoint a database +** +** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X +** on [database connection] D to be [checkpointed]. ^If X is NULL or an +** empty string, then a checkpoint is run on all databases of +** connection D. ^If the database connection D is not in +** [WAL | write-ahead log mode] then this interface is a harmless no-op. +** +** ^The [wal_checkpoint pragma] can be used to invoke this interface +** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the +** [wal_autocheckpoint pragma] can be used to cause this interface to be +** run whenever the WAL reaches a certain size threshold. +** +** See also: [sqlite3_wal_checkpoint_v2()] +*/ +int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); + +/* +** CAPI3REF: Checkpoint a database +** +** Run a checkpoint operation on WAL database zDb attached to database +** handle db. The specific operation is determined by the value of the +** eMode parameter: +** +** <dl> +** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> +** Checkpoint as many frames as possible without waiting for any database +** readers or writers to finish. Sync the db file if all frames in the log +** are checkpointed. This mode is the same as calling +** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. +** +** <dt>SQLITE_CHECKPOINT_FULL<dd> +** This mode blocks (calls the busy-handler callback) until there is no +** database writer and all readers are reading from the most recent database +** snapshot. It then checkpoints all frames in the log file and syncs the +** database file. This call blocks database writers while it is running, +** but not database readers. +** +** <dt>SQLITE_CHECKPOINT_RESTART<dd> +** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after +** checkpointing the log file it blocks (calls the busy-handler callback) +** until all readers are reading from the database file only. This ensures +** that the next client to write to the database file restarts the log file +** from the beginning. This call blocks database writers while it is running, +** but not database readers. +** </dl> +** +** If pnLog is not NULL, then *pnLog is set to the total number of frames in +** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to +** the total number of checkpointed frames (including any that were already +** checkpointed when this function is called). *pnLog and *pnCkpt may be +** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. +** If no values are available because of an error, they are both set to -1 +** before returning to communicate this to the caller. +** +** All calls obtain an exclusive "checkpoint" lock on the database file. If +** any other process is running a checkpoint operation at the same time, the +** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a +** busy-handler configured, it will not be invoked in this case. +** +** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive +** "writer" lock on the database file. If the writer lock cannot be obtained +** immediately, and a busy-handler is configured, it is invoked and the writer +** lock retried until either the busy-handler returns 0 or the lock is +** successfully obtained. The busy-handler is also invoked while waiting for +** database readers as described above. If the busy-handler returns 0 before +** the writer lock is obtained or while waiting for database readers, the +** checkpoint operation proceeds from that point in the same way as +** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible +** without blocking any further. SQLITE_BUSY is returned in this case. +** +** If parameter zDb is NULL or points to a zero length string, then the +** specified operation is attempted on all WAL databases. In this case the +** values written to output parameters *pnLog and *pnCkpt are undefined. If +** an SQLITE_BUSY error is encountered when processing one or more of the +** attached WAL databases, the operation is still attempted on any remaining +** attached databases and SQLITE_BUSY is returned to the caller. If any other +** error occurs while processing an attached database, processing is abandoned +** and the error code returned to the caller immediately. If no error +** (SQLITE_BUSY or otherwise) is encountered while processing the attached +** databases, SQLITE_OK is returned. +** +** If database zDb is the name of an attached database that is not in WAL +** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If +** zDb is not NULL (or a zero length string) and is not the name of any +** attached database, SQLITE_ERROR is returned to the caller. +*/ +int sqlite3_wal_checkpoint_v2( + sqlite3 *db, /* Database handle */ + const char *zDb, /* Name of attached database (or NULL) */ + int eMode, /* SQLITE_CHECKPOINT_* value */ + int *pnLog, /* OUT: Size of WAL log in frames */ + int *pnCkpt /* OUT: Total number of frames checkpointed */ +); + +/* +** CAPI3REF: Checkpoint operation parameters +** +** These constants can be used as the 3rd parameter to +** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] +** documentation for additional information about the meaning and use of +** each of these values. +*/ +#define SQLITE_CHECKPOINT_PASSIVE 0 +#define SQLITE_CHECKPOINT_FULL 1 +#define SQLITE_CHECKPOINT_RESTART 2 + +/* +** CAPI3REF: Virtual Table Interface Configuration +** +** This function may be called by either the [xConnect] or [xCreate] method +** of a [virtual table] implementation to configure +** various facets of the virtual table interface. +** +** If this interface is invoked outside the context of an xConnect or +** xCreate virtual table method then the behavior is undefined. +** +** At present, there is only one option that may be configured using +** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options +** may be added in the future. +*/ +int sqlite3_vtab_config(sqlite3*, int op, ...); + +/* +** CAPI3REF: Virtual Table Configuration Options +** +** These macros define the various options to the +** [sqlite3_vtab_config()] interface that [virtual table] implementations +** can use to customize and optimize their behavior. +** +** <dl> +** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT +** <dd>Calls of the form +** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, +** where X is an integer. If X is zero, then the [virtual table] whose +** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not +** support constraints. In this configuration (which is the default) if +** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire +** statement is rolled back as if [ON CONFLICT | OR ABORT] had been +** specified as part of the users SQL statement, regardless of the actual +** ON CONFLICT mode specified. +** +** If X is non-zero, then the virtual table implementation guarantees +** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before +** any modifications to internal or persistent data structures have been made. +** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite +** is able to roll back a statement or database transaction, and abandon +** or continue processing the current SQL statement as appropriate. +** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns +** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode +** had been ABORT. +** +** Virtual table implementations that are required to handle OR REPLACE +** must do so within the [xUpdate] method. If a call to the +** [sqlite3_vtab_on_conflict()] function indicates that the current ON +** CONFLICT policy is REPLACE, the virtual table implementation should +** silently replace the appropriate rows within the xUpdate callback and +** return SQLITE_OK. Or, if this is not possible, it may return +** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT +** constraint handling. +** </dl> +*/ +#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 + +/* +** CAPI3REF: Determine The Virtual Table Conflict Policy +** +** This function may only be called from within a call to the [xUpdate] method +** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The +** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], +** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode +** of the SQL statement that triggered the call to the [xUpdate] method of the +** [virtual table]. +*/ +int sqlite3_vtab_on_conflict(sqlite3 *); + +/* +** CAPI3REF: Conflict resolution modes +** +** These constants are returned by [sqlite3_vtab_on_conflict()] to +** inform a [virtual table] implementation what the [ON CONFLICT] mode +** is for the SQL statement being evaluated. +** +** Note that the [SQLITE_IGNORE] constant is also used as a potential +** return value from the [sqlite3_set_authorizer()] callback and that +** [SQLITE_ABORT] is also a [result code]. +*/ +#define SQLITE_ROLLBACK 1 +/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ +#define SQLITE_FAIL 3 +/* #define SQLITE_ABORT 4 // Also an error code */ +#define SQLITE_REPLACE 5 + + + +/* +** Undo the hack that converts floating point types to integer for +** builds on processors without floating point support. +*/ +#ifdef SQLITE_OMIT_FLOATING_POINT +# undef double +#endif + +#ifdef __cplusplus +} /* End of the 'extern "C"' block */ +#endif +#endif |