DBD-SQLite
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** 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;
# ifdef SQLITE_UINT64_TYPE
typedef SQLITE_UINT64_TYPE sqlite_uint64;
# else
typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
# endif
#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
** DESTRUCTOR: sqlite3
**
** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
** for the [sqlite3] object.
** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
** the [sqlite3] object is successfully destroyed and all associated
** resources are deallocated.
**
** Ideally, applications should [sqlite3_finalize | finalize] all
** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
** with the [sqlite3] object prior to attempting to close the object.
** ^If the database connection is associated with unfinalized prepared
** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
** sqlite3_close() will leave the database connection open and return
** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
** it returns [SQLITE_OK] regardless, but instead of deallocating the database
** connection immediately, it marks the database connection as an unusable
** "zombie" and makes arrangements to automatically deallocate the database
** connection after all prepared statements are finalized, all BLOB handles
** are closed, and all backups have finished. The sqlite3_close_v2() interface
** is intended for use with host languages that are garbage collected, and
** where the order in which destructors are called is arbitrary.
**
** ^If an [sqlite3] object is destroyed while a transaction is open,
** the transaction is automatically rolled back.
**
** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(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() or sqlite3_close_v2() with a NULL pointer
** argument is a harmless no-op.
*/
SQLITE_API int sqlite3_close(sqlite3*);
SQLITE_API int sqlite3_close_v2(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
** METHOD: sqlite3
**
** 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-separated 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
** 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.
**
** 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 become 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_methods2
** functions.
**
** [[the xShrink() page cache method]]
** ^SQLite invokes the xShrink() method when it wants the page cache to
** free up as much of heap memory as possible. The page cache implementation
** is not obligated to free any memory, but well-behaved implementations should
** do their best.
*/
typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
struct sqlite3_pcache_methods2 {
int iVersion;
void *pArg;
int (*xInit)(void*);
void (*xShutdown)(void*);
sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
void (*xCachesize)(sqlite3_pcache*, int nCachesize);
int (*xPagecount)(sqlite3_pcache*);
sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
unsigned oldKey, unsigned newKey);
void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
void (*xDestroy)(sqlite3_pcache*);
void (*xShrink)(sqlite3_pcache*);
};
/*
** This is the obsolete pcache_methods object that has now been replaced
** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
** retained in the header file for backwards compatibility only.
*/
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.
**
** ^A call to sqlite3_backup_init() will fail, returning NULL, if
** there is already a read or read-write transaction open on the
** destination database.
**
** ^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 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 of 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>
**
** ^The sqlite3_backup_remaining() routine returns the number of pages still
** to be backed up at the conclusion of the most recent sqlite3_backup_step().
** ^The sqlite3_backup_pagecount() routine returns the total number of pages
** in the source database at the conclusion of the most recent
** sqlite3_backup_step().
** ^(The values returned by these functions are only updated by
** sqlite3_backup_step(). If the source database is modified in a way that
** changes the size of the source database or the number of pages remaining,
** those changes are not reflected in the output of sqlite3_backup_pagecount()
** and sqlite3_backup_remaining() until after the next
** sqlite3_backup_step().)^
**
** <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 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.
**
** <b>Alternatives To Using The Backup API</b>
**
** Other techniques for safely creating a consistent backup of an SQLite
** database include:
**
** <ul>
** <li> The [VACUUM INTO] command.
** <li> The [sqlite3_rsync] utility program.
** </ul>
*/
SQLITE_API 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 */
);
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
/*
** CAPI3REF: Unlock Notification
** METHOD: sqlite3
**
** ^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 connection's current transaction is concluded. ^The
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
** call that concludes the blocking connection's 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 connection's
** 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
** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
** the returned buffer content will remain accessible and unchanged
** until either the next write operation on the connection or when
** the connection is closed, and applications must not modify the
** buffer. If the bit had been clear, the returned buffer will not
** be accessed by SQLite after the call.
**
** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
** allocation error occurs.
**
** This interface is omitted if SQLite is compiled with the
** [SQLITE_OMIT_DESERIALIZE] option.
*/
SQLITE_API unsigned char *sqlite3_serialize(
sqlite3 *db, /* The database connection */
const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
);
/*
** CAPI3REF: Flags for sqlite3_serialize
**
** Zero or more of the following constants can be OR-ed together for
** the F argument to [sqlite3_serialize(D,S,P,F)].
**
** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
** a pointer to contiguous in-memory database that it is currently using,
** without making a copy of the database. If SQLite is not currently using
** a contiguous in-memory database, then this option causes
** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
** using a contiguous in-memory database if it has been initialized by a
** prior call to [sqlite3_deserialize()].
*/
#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
/*
** CAPI3REF: Deserialize a database
**
** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
** [database connection] D to disconnect from database S and then
** reopen S as an in-memory database based on the serialization
** contained in P. If S is a NULL pointer, the main database is
** used. The serialized database P is N bytes in size. M is the size
** of the buffer P, which might be larger than N. If M is larger than
** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then
** SQLite is permitted to add content to the in-memory database as
** long as the total size does not exceed M bytes.
**
** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
** invoke sqlite3_free() on the serialization buffer when the database
** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
** SQLite will try to increase the buffer size using sqlite3_realloc64()
** if writes on the database cause it to grow larger than M bytes.
**
** Applications must not modify the buffer P or invalidate it before
** the database connection D is closed.
**
** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
** database is currently in a read transaction or is involved in a backup
** operation.
**
** It is not possible to deserialize into the TEMP database. If the
** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
** function returns SQLITE_ERROR.
**
** The deserialized database should not be in [WAL mode]. If the database
** is in WAL mode, then any attempt to use the database file will result
** in an [SQLITE_CANTOPEN] error. The application can set the
** [file format version numbers] (bytes 18 and 19) of the input database P
** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
** database file into rollback mode and work around this limitation.
**
** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
** [sqlite3_free()] is invoked on argument P prior to returning.
**
** This interface is omitted if SQLite is compiled with the
** [SQLITE_OMIT_DESERIALIZE] option.
*/
SQLITE_API int sqlite3_deserialize(
sqlite3 *db, /* The database connection */
const char *zSchema, /* Which DB to reopen with the deserialization */
unsigned char *pData, /* The serialized database content */
sqlite3_int64 szDb, /* Number of bytes in the deserialization */
sqlite3_int64 szBuf, /* Total size of buffer pData[] */
unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
);
/*
** CAPI3REF: Flags for sqlite3_deserialize()
**
** The following are allowed values for the 6th argument (the F argument) to
** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
**
** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
** in the P argument is held in memory obtained from [sqlite3_malloc64()]
** and that SQLite should take ownership of this memory and automatically
** free it when it has finished using it. Without this flag, the caller
** is responsible for freeing any dynamically allocated memory.
**
** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
** grow the size of the database using calls to [sqlite3_realloc64()]. This
** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
** Without this flag, the deserialized database cannot increase in size beyond
** the number of bytes specified by the M parameter.
**
** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
** should be treated as read-only.
*/
#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
/*
** CAPI3REF: Bind array values to the CARRAY table-valued function
**
** The sqlite3_carray_bind(S,I,P,N,F,X) interface binds an array value to
** one of the first argument of the [carray() table-valued function]. The
** S parameter is a pointer to the [prepared statement] that uses the carray()
*/
#define isOpen(pFd) ((pFd)->pMethods!=0)
/*
** Flags that make up the mask passed to sqlite3PagerGet().
*/
#define PAGER_GET_NOCONTENT 0x01 /* Do not load data from disk */
#define PAGER_GET_READONLY 0x02 /* Read-only page is acceptable */
/*
** Flags for sqlite3PagerSetFlags()
**
** Value constraints (enforced via assert()):
** PAGER_FULLFSYNC == SQLITE_FullFSync
** PAGER_CKPT_FULLFSYNC == SQLITE_CkptFullFSync
** PAGER_CACHE_SPILL == SQLITE_CacheSpill
*/
#define PAGER_SYNCHRONOUS_OFF 0x01 /* PRAGMA synchronous=OFF */
#define PAGER_SYNCHRONOUS_NORMAL 0x02 /* PRAGMA synchronous=NORMAL */
#define PAGER_SYNCHRONOUS_FULL 0x03 /* PRAGMA synchronous=FULL */
#define PAGER_SYNCHRONOUS_EXTRA 0x04 /* PRAGMA synchronous=EXTRA */
#define PAGER_SYNCHRONOUS_MASK 0x07 /* Mask for four values above */
#define PAGER_FULLFSYNC 0x08 /* PRAGMA fullfsync=ON */
#define PAGER_CKPT_FULLFSYNC 0x10 /* PRAGMA checkpoint_fullfsync=ON */
#define PAGER_CACHESPILL 0x20 /* PRAGMA cache_spill=ON */
#define PAGER_FLAGS_MASK 0x38 /* All above except SYNCHRONOUS */
/*
** The remainder of this file contains the declarations of the functions
** that make up the Pager sub-system API. See source code comments for
** a detailed description of each routine.
*/
/* Open and close a Pager connection. */
SQLITE_PRIVATE int sqlite3PagerOpen(
sqlite3_vfs*,
Pager **ppPager,
const char*,
int,
int,
int,
void(*)(DbPage*)
);
SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager, sqlite3*);
SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
/* Functions used to configure a Pager object. */
SQLITE_PRIVATE void sqlite3PagerSetBusyHandler(Pager*, int(*)(void *), void *);
SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u32*, int);
SQLITE_PRIVATE Pgno sqlite3PagerMaxPageCount(Pager*, Pgno);
SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);
SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager*, int);
SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
SQLITE_PRIVATE void sqlite3PagerShrink(Pager*);
SQLITE_PRIVATE void sqlite3PagerSetFlags(Pager*,unsigned);
SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *, int);
SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *, int);
SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager*);
SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager*);
SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
SQLITE_PRIVATE int sqlite3PagerFlush(Pager*);
/* Functions used to obtain and release page references. */
SQLITE_PRIVATE int sqlite3PagerGet(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
SQLITE_PRIVATE void sqlite3PagerRef(DbPage*);
SQLITE_PRIVATE void sqlite3PagerUnref(DbPage*);
SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage*);
SQLITE_PRIVATE void sqlite3PagerUnrefPageOne(DbPage*);
/* Operations on page references. */
SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*);
SQLITE_PRIVATE void sqlite3PagerDontWrite(DbPage*);
SQLITE_PRIVATE int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int);
SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage*);
SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *);
SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *);
/* Functions used to manage pager transactions and savepoints. */
SQLITE_PRIVATE void sqlite3PagerPagecount(Pager*, int*);
SQLITE_PRIVATE int sqlite3PagerBegin(Pager*, int exFlag, int);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zSuper, int);
SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager*);
SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zSuper);
SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*);
SQLITE_PRIVATE int sqlite3PagerRollback(Pager*);
SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);
SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager);
#ifndef SQLITE_OMIT_WAL
SQLITE_PRIVATE int sqlite3PagerCheckpoint(Pager *pPager, sqlite3*, int, int*, int*);
SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager);
SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager);
SQLITE_PRIVATE int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);
SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager, sqlite3*);
# ifdef SQLITE_ENABLE_SNAPSHOT
SQLITE_PRIVATE int sqlite3PagerSnapshotGet(Pager*, sqlite3_snapshot **ppSnapshot);
SQLITE_PRIVATE int sqlite3PagerSnapshotOpen(Pager*, sqlite3_snapshot *pSnapshot);
SQLITE_PRIVATE int sqlite3PagerSnapshotRecover(Pager *pPager);
SQLITE_PRIVATE int sqlite3PagerSnapshotCheck(Pager *pPager, sqlite3_snapshot *pSnapshot);
SQLITE_PRIVATE void sqlite3PagerSnapshotUnlock(Pager *pPager);
# endif
#endif
#if !defined(SQLITE_OMIT_WAL) && defined(SQLITE_ENABLE_SETLK_TIMEOUT)
SQLITE_PRIVATE int sqlite3PagerWalWriteLock(Pager*, int);
SQLITE_PRIVATE void sqlite3PagerWalDb(Pager*, sqlite3*);
#else
# define sqlite3PagerWalWriteLock(y,z) SQLITE_OK
# define sqlite3PagerWalDb(x,y)
#endif
#ifdef SQLITE_DIRECT_OVERFLOW_READ
SQLITE_PRIVATE int sqlite3PagerDirectReadOk(Pager *pPager, Pgno pgno);
#endif
#ifdef SQLITE_ENABLE_ZIPVFS
SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager);
#endif
SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
SQLITE_PRIVATE void sqlite3AlterDropColumn(Parse*, SrcList*, const Token*);
SQLITE_PRIVATE const void *sqlite3RenameTokenMap(Parse*, const void*, const Token*);
SQLITE_PRIVATE void sqlite3RenameTokenRemap(Parse*, const void *pTo, const void *pFrom);
SQLITE_PRIVATE void sqlite3RenameExprUnmap(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3RenameExprlistUnmap(Parse*, ExprList*);
SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
SQLITE_PRIVATE char sqlite3AffinityType(const char*, Column*);
SQLITE_PRIVATE void sqlite3Analyze(Parse*, Token*, Token*);
SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler*);
SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *, const char *);
SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3*,int iDB);
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3*,Index*);
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);
SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);
SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
SQLITE_PRIVATE void sqlite3SchemaClear(void *);
SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);
SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo*);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo*);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoFromExprList(Parse*, ExprList*, int, int);
SQLITE_PRIVATE const char *sqlite3SelectOpName(int);
SQLITE_PRIVATE int sqlite3HasExplicitNulls(Parse*, ExprList*);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo*);
#endif
SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
void (*)(sqlite3_context*,int,sqlite3_value **),
void (*)(sqlite3_context*,int,sqlite3_value **),
void (*)(sqlite3_context*),
void (*)(sqlite3_context*),
void (*)(sqlite3_context*,int,sqlite3_value **),
FuncDestructor *pDestructor
);
SQLITE_PRIVATE void sqlite3NoopDestructor(void*);
SQLITE_PRIVATE void *sqlite3OomFault(sqlite3*);
SQLITE_PRIVATE void sqlite3OomClear(sqlite3*);
SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);
SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);
SQLITE_PRIVATE char *sqlite3RCStrRef(char*);
SQLITE_PRIVATE void sqlite3RCStrUnref(void*);
SQLITE_PRIVATE char *sqlite3RCStrNew(u64);
SQLITE_PRIVATE char *sqlite3RCStrResize(char*,u64);
SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
SQLITE_PRIVATE int sqlite3StrAccumEnlarge(StrAccum*, i64);
SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);
SQLITE_PRIVATE void sqlite3StrAccumSetError(StrAccum*, u8);
SQLITE_PRIVATE void sqlite3ResultStrAccum(sqlite3_context*,StrAccum*);
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);
SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
SQLITE_PRIVATE void sqlite3RecordErrorByteOffset(sqlite3*,const char*);
SQLITE_PRIVATE void sqlite3RecordErrorOffsetOfExpr(sqlite3*,const Expr*);
SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);
SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse*, Expr*);
#else
# define sqlite3ExprCheckIN(x,y) SQLITE_OK
#endif
#ifdef SQLITE_ENABLE_STAT4
SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(
Parse*,Index*,UnpackedRecord**,Expr*,int,int,int*);
SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);
SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);
SQLITE_PRIVATE int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3*, Index*, int);
#endif
/*
** The interface to the LEMON-generated parser
*/
#ifndef SQLITE_AMALGAMATION
SQLITE_PRIVATE void *sqlite3ParserAlloc(void*(*)(u64), Parse*);
SQLITE_PRIVATE void sqlite3ParserFree(void*, void(*)(void*));
#endif
SQLITE_PRIVATE void sqlite3Parser(void*, int, Token);
SQLITE_PRIVATE int sqlite3ParserFallback(int);
#ifdef YYTRACKMAXSTACKDEPTH
SQLITE_PRIVATE int sqlite3ParserStackPeak(void*);
#endif
SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3*);
#ifndef SQLITE_OMIT_LOAD_EXTENSION
SQLITE_PRIVATE void sqlite3CloseExtensions(sqlite3*);
#else
# define sqlite3CloseExtensions(X)
#endif
#ifndef SQLITE_OMIT_SHARED_CACHE
SQLITE_PRIVATE void sqlite3TableLock(Parse *, int, Pgno, u8, const char *);
#else
#define sqlite3TableLock(v,w,x,y,z)
#endif
#ifdef SQLITE_TEST
SQLITE_PRIVATE int sqlite3Utf8To8(unsigned char*);
#endif
#ifdef SQLITE_OMIT_VIRTUALTABLE
# define sqlite3VtabClear(D,T)
# define sqlite3VtabSync(X,Y) SQLITE_OK
# define sqlite3VtabRollback(X)
# define sqlite3VtabCommit(X)
# define sqlite3VtabInSync(db) 0
# define sqlite3VtabLock(X)
# define sqlite3VtabUnlock(X)
# define sqlite3VtabModuleUnref(D,X)
# define sqlite3VtabUnlockList(X)
# define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
# define sqlite3GetVTable(X,Y) ((VTable*)0)
#else
SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table*);
SimulateDiskfullError( return SQLITE_FULL );
assert( pFile );
OSTRACE(("SYNC %-3d\n", pFile->h));
rc = full_fsync(pFile->h, isFullsync, isDataOnly);
SimulateIOError( rc=1 );
if( rc ){
storeLastErrno(pFile, errno);
return unixLogError(SQLITE_IOERR_FSYNC, "full_fsync", pFile->zPath);
}
/* Also fsync the directory containing the file if the DIRSYNC flag
** is set. This is a one-time occurrence. Many systems (examples: AIX)
** are unable to fsync a directory, so ignore errors on the fsync.
*/
if( pFile->ctrlFlags & UNIXFILE_DIRSYNC ){
int dirfd;
OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,
HAVE_FULLFSYNC, isFullsync));
rc = osOpenDirectory(pFile->zPath, &dirfd);
if( rc==SQLITE_OK ){
full_fsync(dirfd, 0, 0);
robust_close(pFile, dirfd, __LINE__);
}else{
assert( rc==SQLITE_CANTOPEN );
rc = SQLITE_OK;
}
pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;
}
return rc;
}
/*
** Truncate an open file to a specified size
*/
static int unixTruncate(sqlite3_file *id, i64 nByte){
unixFile *pFile = (unixFile *)id;
int rc;
assert( pFile );
SimulateIOError( return SQLITE_IOERR_TRUNCATE );
/* If the user has configured a chunk-size for this file, truncate the
** file so that it consists of an integer number of chunks (i.e. the
** actual file size after the operation may be larger than the requested
** size).
*/
if( pFile->szChunk>0 ){
nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
}
rc = robust_ftruncate(pFile->h, nByte);
if( rc ){
storeLastErrno(pFile, errno);
return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
}else{
#ifdef SQLITE_DEBUG
/* If we are doing a normal write to a database file (as opposed to
** doing a hot-journal rollback or a write to some file other than a
** normal database file) and we truncate the file to zero length,
** that effectively updates the change counter. This might happen
** when restoring a database using the backup API from a zero-length
** source.
*/
if( pFile->inNormalWrite && nByte==0 ){
pFile->transCntrChng = 1;
}
#endif
#if SQLITE_MAX_MMAP_SIZE>0
/* If the file was just truncated to a size smaller than the currently
** mapped region, reduce the effective mapping size as well. SQLite will
** use read() and write() to access data beyond this point from now on.
*/
if( nByte<pFile->mmapSize ){
pFile->mmapSize = nByte;
}
#endif
return SQLITE_OK;
}
}
/*
** Determine the current size of a file in bytes
*/
static int unixFileSize(sqlite3_file *id, i64 *pSize){
int rc;
struct stat buf;
assert( id );
rc = osFstat(((unixFile*)id)->h, &buf);
SimulateIOError( rc=1 );
if( rc!=0 ){
storeLastErrno((unixFile*)id, errno);
return SQLITE_IOERR_FSTAT;
}
*pSize = buf.st_size;
/* When opening a zero-size database, the findInodeInfo() procedure
** writes a single byte into that file in order to work around a bug
** in the OS-X msdos filesystem. In order to avoid problems with upper
** layers, we need to report this file size as zero even though it is
** really 1. Ticket #3260.
*/
if( *pSize==1 ) *pSize = 0;
return SQLITE_OK;
}
#if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)
/*
** Handler for proxy-locking file-control verbs. Defined below in the
** proxying locking division.
*/
static int proxyFileControl(sqlite3_file*,int,void*);
#endif
/*
** This function is called to handle the SQLITE_FCNTL_SIZE_HINT
** file-control operation. Enlarge the database to nBytes in size
** (rounded up to the next chunk-size). If the database is already
**
** syncFlags, walSyncFlags
**
** syncFlags is either SQLITE_SYNC_NORMAL (0x02) or SQLITE_SYNC_FULL (0x03).
** syncFlags is used for rollback mode. walSyncFlags is used for WAL mode
** and contains the flags used to sync the checkpoint operations in the
** lower two bits, and sync flags used for transaction commits in the WAL
** file in bits 0x04 and 0x08. In other words, to get the correct sync flags
** for checkpoint operations, use (walSyncFlags&0x03) and to get the correct
** sync flags for transaction commit, use ((walSyncFlags>>2)&0x03). Note
** that with synchronous=NORMAL in WAL mode, transaction commit is not synced
** meaning that the 0x04 and 0x08 bits are both zero.
*/
struct Pager {
sqlite3_vfs *pVfs; /* OS functions to use for IO */
u8 exclusiveMode; /* Boolean. True if locking_mode==EXCLUSIVE */
u8 journalMode; /* One of the PAGER_JOURNALMODE_* values */
u8 useJournal; /* Use a rollback journal on this file */
u8 noSync; /* Do not sync the journal if true */
u8 fullSync; /* Do extra syncs of the journal for robustness */
u8 extraSync; /* sync directory after journal delete */
u8 syncFlags; /* SYNC_NORMAL or SYNC_FULL otherwise */
u8 walSyncFlags; /* See description above */
u8 tempFile; /* zFilename is a temporary or immutable file */
u8 noLock; /* Do not lock (except in WAL mode) */
u8 readOnly; /* True for a read-only database */
u8 memDb; /* True to inhibit all file I/O */
u8 memVfs; /* VFS-implemented memory database */
/**************************************************************************
** The following block contains those class members that change during
** routine operation. Class members not in this block are either fixed
** when the pager is first created or else only change when there is a
** significant mode change (such as changing the page_size, locking_mode,
** or the journal_mode). From another view, these class members describe
** the "state" of the pager, while other class members describe the
** "configuration" of the pager.
*/
u8 eState; /* Pager state (OPEN, READER, WRITER_LOCKED..) */
u8 eLock; /* Current lock held on database file */
u8 changeCountDone; /* Set after incrementing the change-counter */
u8 setSuper; /* Super-jrnl name is written into jrnl */
u8 doNotSpill; /* Do not spill the cache when non-zero */
u8 subjInMemory; /* True to use in-memory sub-journals */
u8 bUseFetch; /* True to use xFetch() */
u8 hasHeldSharedLock; /* True if a shared lock has ever been held */
Pgno dbSize; /* Number of pages in the database */
Pgno dbOrigSize; /* dbSize before the current transaction */
Pgno dbFileSize; /* Number of pages in the database file */
Pgno dbHintSize; /* Value passed to FCNTL_SIZE_HINT call */
int errCode; /* One of several kinds of errors */
int nRec; /* Pages journalled since last j-header written */
u32 cksumInit; /* Quasi-random value added to every checksum */
u32 nSubRec; /* Number of records written to sub-journal */
Bitvec *pInJournal; /* One bit for each page in the database file */
sqlite3_file *fd; /* File descriptor for database */
sqlite3_file *jfd; /* File descriptor for main journal */
sqlite3_file *sjfd; /* File descriptor for sub-journal */
i64 journalOff; /* Current write offset in the journal file */
i64 journalHdr; /* Byte offset to previous journal header */
sqlite3_backup *pBackup; /* Pointer to list of ongoing backup processes */
PagerSavepoint *aSavepoint; /* Array of active savepoints */
int nSavepoint; /* Number of elements in aSavepoint[] */
u32 iDataVersion; /* Changes whenever database content changes */
char dbFileVers[16]; /* Changes whenever database file changes */
int nMmapOut; /* Number of mmap pages currently outstanding */
sqlite3_int64 szMmap; /* Desired maximum mmap size */
PgHdr *pMmapFreelist; /* List of free mmap page headers (pDirty) */
/*
** End of the routinely-changing class members
***************************************************************************/
u16 nExtra; /* Add this many bytes to each in-memory page */
i16 nReserve; /* Number of unused bytes at end of each page */
u32 vfsFlags; /* Flags for sqlite3_vfs.xOpen() */
u32 sectorSize; /* Assumed sector size during rollback */
Pgno mxPgno; /* Maximum allowed size of the database */
Pgno lckPgno; /* Page number for the locking page */
i64 pageSize; /* Number of bytes in a page */
i64 journalSizeLimit; /* Size limit for persistent journal files */
char *zFilename; /* Name of the database file */
char *zJournal; /* Name of the journal file */
int (*xBusyHandler)(void*); /* Function to call when busy */
void *pBusyHandlerArg; /* Context argument for xBusyHandler */
u32 aStat[4]; /* Total cache hits, misses, writes, spills */
#ifdef SQLITE_TEST
int nRead; /* Database pages read */
#endif
void (*xReiniter)(DbPage*); /* Call this routine when reloading pages */
int (*xGet)(Pager*,Pgno,DbPage**,int); /* Routine to fetch a patch */
char *pTmpSpace; /* Pager.pageSize bytes of space for tmp use */
PCache *pPCache; /* Pointer to page cache object */
#ifndef SQLITE_OMIT_WAL
Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */
char *zWal; /* File name for write-ahead log */
#endif
#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
sqlite3 *dbWal;
#endif
};
/*
** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains
** the values accessed by passing SQLITE_DBSTATUS_CACHE_HIT, CACHE_MISS
** or CACHE_WRITE to sqlite3_db_status().
*/
#define PAGER_STAT_HIT 0
#define PAGER_STAT_MISS 1
#define PAGER_STAT_WRITE 2
#define PAGER_STAT_SPILL 3
/*
** The following global variables hold counters used for
** testing purposes only. These variables do not exist in
** a non-testing build. These variables are not thread-safe.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_pager_readdb_count = 0; /* Number of full pages read from DB */
SQLITE_API int sqlite3_pager_writedb_count = 0; /* Number of full pages written to DB */
SQLITE_API int sqlite3_pager_writej_count = 0; /* Number of pages written to journal */
PAGERID(pPager), pPg->pgno, pager_pagehash(pPg)));
return rc;
}
/*
** Update the value of the change-counter at offsets 24 and 92 in
** the header and the sqlite version number at offset 96.
**
** This is an unconditional update. See also the pager_incr_changecounter()
** routine which only updates the change-counter if the update is actually
** needed, as determined by the pPager->changeCountDone state variable.
*/
static void pager_write_changecounter(PgHdr *pPg){
u32 change_counter;
if( NEVER(pPg==0) ) return;
/* Increment the value just read and write it back to byte 24. */
change_counter = sqlite3Get4byte((u8*)pPg->pPager->dbFileVers)+1;
put32bits(((char*)pPg->pData)+24, change_counter);
/* Also store the SQLite version number in bytes 96..99 and in
** bytes 92..95 store the change counter for which the version number
** is valid. */
put32bits(((char*)pPg->pData)+92, change_counter);
put32bits(((char*)pPg->pData)+96, SQLITE_VERSION_NUMBER);
}
#ifndef SQLITE_OMIT_WAL
/*
** This function is invoked once for each page that has already been
** written into the log file when a WAL transaction is rolled back.
** Parameter iPg is the page number of said page. The pCtx argument
** is actually a pointer to the Pager structure.
**
** If page iPg is present in the cache, and has no outstanding references,
** it is discarded. Otherwise, if there are one or more outstanding
** references, the page content is reloaded from the database. If the
** attempt to reload content from the database is required and fails,
** return an SQLite error code. Otherwise, SQLITE_OK.
*/
static int pagerUndoCallback(void *pCtx, Pgno iPg){
int rc = SQLITE_OK;
Pager *pPager = (Pager *)pCtx;
PgHdr *pPg;
assert( pagerUseWal(pPager) );
pPg = sqlite3PagerLookup(pPager, iPg);
if( pPg ){
if( sqlite3PcachePageRefcount(pPg)==1 ){
sqlite3PcacheDrop(pPg);
}else{
rc = readDbPage(pPg);
if( rc==SQLITE_OK ){
pPager->xReiniter(pPg);
}
sqlite3PagerUnrefNotNull(pPg);
}
}
/* Normally, if a transaction is rolled back, any backup processes are
** updated as data is copied out of the rollback journal and into the
** database. This is not generally possible with a WAL database, as
** rollback involves simply truncating the log file. Therefore, if one
** or more frames have already been written to the log (and therefore
** also copied into the backup databases) as part of this transaction,
** the backups must be restarted.
*/
sqlite3BackupRestart(pPager->pBackup);
return rc;
}
/*
** This function is called to rollback a transaction on a WAL database.
*/
static int pagerRollbackWal(Pager *pPager){
int rc; /* Return Code */
PgHdr *pList; /* List of dirty pages to revert */
/* For all pages in the cache that are currently dirty or have already
** been written (but not committed) to the log file, do one of the
** following:
**
** + Discard the cached page (if refcount==0), or
** + Reload page content from the database (if refcount>0).
*/
pPager->dbSize = pPager->dbOrigSize;
rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager);
pList = sqlite3PcacheDirtyList(pPager->pPCache);
while( pList && rc==SQLITE_OK ){
PgHdr *pNext = pList->pDirty;
rc = pagerUndoCallback((void *)pPager, pList->pgno);
pList = pNext;
}
return rc;
}
/*
** This function is a wrapper around sqlite3WalFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed.
**
** The list of pages passed into this routine is always sorted by page number.
** Hence, if page 1 appears anywhere on the list, it will be the first page.
*/
static int pagerWalFrames(
Pager *pPager, /* Pager object */
PgHdr *pList, /* List of frames to log */
Pgno nTruncate, /* Database size after this commit */
int isCommit /* True if this is a commit */
){
int rc; /* Return code */
int nList; /* Number of pages in pList */
PgHdr *p; /* For looping over pages */
assert( pPager->pWal );
assert( pList );
#ifdef SQLITE_DEBUG
/* Verify that the page list is in ascending order */
for(p=pList; p && p->pDirty; p=p->pDirty){
assert( p->pgno < p->pDirty->pgno );
}
#endif
assert( pList->pDirty==0 || isCommit );
if( isCommit ){
/* If a WAL transaction is being committed, there is no point in writing
** any pages with page numbers greater than nTruncate into the WAL file.
** They will never be read by any client. So remove them from the pDirty
** list here. */
PgHdr **ppNext = &pList;
nList = 0;
for(p=pList; (*ppNext = p)!=0; p=p->pDirty){
if( p->pgno<=nTruncate ){
ppNext = &p->pDirty;
nList++;
}
}
assert( pList );
}else{
nList = 1;
}
pPager->aStat[PAGER_STAT_WRITE] += nList;
if( pList->pgno==1 ) pager_write_changecounter(pList);
rc = sqlite3WalFrames(pPager->pWal,
pPager->pageSize, pList, nTruncate, isCommit, pPager->walSyncFlags
);
if( rc==SQLITE_OK && pPager->pBackup ){
for(p=pList; p; p=p->pDirty){
sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
}
}
#ifdef SQLITE_CHECK_PAGES
pList = sqlite3PcacheDirtyList(pPager->pPCache);
for(p=pList; p; p=p->pDirty){
pager_set_pagehash(p);
}
#endif
assert( pPager->eLock==EXCLUSIVE_LOCK );
assert( isOpen(pPager->fd) || pList->pDirty==0 );
/* If the file is a temp-file has not yet been opened, open it now. It
** is not possible for rc to be other than SQLITE_OK if this branch
** is taken, as pager_wait_on_lock() is a no-op for temp-files.
*/
if( !isOpen(pPager->fd) ){
assert( pPager->tempFile && rc==SQLITE_OK );
rc = pagerOpentemp(pPager, pPager->fd, pPager->vfsFlags);
}
/* Before the first write, give the VFS a hint of what the final
** file size will be.
*/
assert( rc!=SQLITE_OK || isOpen(pPager->fd) );
if( rc==SQLITE_OK
&& pPager->dbHintSize<pPager->dbSize
&& (pList->pDirty || pList->pgno>pPager->dbHintSize)
){
sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
pPager->dbHintSize = pPager->dbSize;
}
while( rc==SQLITE_OK && pList ){
Pgno pgno = pList->pgno;
/* If there are dirty pages in the page cache with page numbers greater
** than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to
** make the file smaller (presumably by auto-vacuum code). Do not write
** any such pages to the file.
**
** Also, do not write out any page that has the PGHDR_DONT_WRITE flag
** set (set by sqlite3PagerDontWrite()).
*/
if( pgno<=pPager->dbSize && 0==(pList->flags&PGHDR_DONT_WRITE) ){
i64 offset = (pgno-1)*(i64)pPager->pageSize; /* Offset to write */
char *pData; /* Data to write */
assert( (pList->flags&PGHDR_NEED_SYNC)==0 );
if( pList->pgno==1 ) pager_write_changecounter(pList);
pData = pList->pData;
/* Write out the page data. */
rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);
/* If page 1 was just written, update Pager.dbFileVers to match
** the value now stored in the database file. If writing this
** page caused the database file to grow, update dbFileSize.
*/
if( pgno==1 ){
memcpy(&pPager->dbFileVers, &pData[24], sizeof(pPager->dbFileVers));
}
if( pgno>pPager->dbFileSize ){
pPager->dbFileSize = pgno;
}
pPager->aStat[PAGER_STAT_WRITE]++;
/* Update any backup objects copying the contents of this pager. */
sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)pList->pData);
PAGERTRACE(("STORE %d page %d hash(%08x)\n",
PAGERID(pPager), pgno, pager_pagehash(pList)));
IOTRACE(("PGOUT %p %d\n", pPager, pgno));
PAGER_INCR(sqlite3_pager_writedb_count);
}else{
PAGERTRACE(("NOSTORE %d page %d\n", PAGERID(pPager), pgno));
}
pager_set_pagehash(pList);
pList = pList->pDirty;
}
return rc;
}
/*
** Ensure that the sub-journal file is open. If it is already open, this
** function is a no-op.
**
** SQLITE_OK is returned if everything goes according to plan. An
** SQLITE_IOERR_XXX error code is returned if a call to sqlite3OsOpen()
** fails.
*/
static int openSubJournal(Pager *pPager){
int rc = SQLITE_OK;
if( !isOpen(pPager->sjfd) ){
const int flags = SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_READWRITE
| SQLITE_OPEN_CREATE | SQLITE_OPEN_EXCLUSIVE
| SQLITE_OPEN_DELETEONCLOSE;
int nStmtSpill = sqlite3Config.nStmtSpill;
if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
nStmtSpill = -1;
}
rc = sqlite3JournalOpen(pPager->pVfs, 0, pPager->sjfd, flags, nStmtSpill);
}
return rc;
}
/*
** Append a record of the current state of page pPg to the sub-journal.
**
** If successful, set the bit corresponding to pPg->pgno in the bitvecs
** for all open savepoints before returning.
**
** This function returns SQLITE_OK if everything is successful, an IO
** error code if the attempt to write to the sub-journal fails, or
** SQLITE_NOMEM if a malloc fails while setting a bit in a savepoint
** bitvec.
*/
static int subjournalPage(PgHdr *pPg){
int rc = SQLITE_OK;
Pager *pPager = pPg->pPager;
if( pPager->journalMode!=PAGER_JOURNALMODE_OFF ){
/* Open the sub-journal, if it has not already been opened */
assert( pPager->useJournal );
assert( isOpen(pPager->jfd) || pagerUseWal(pPager) );
assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 );
assert( pagerUseWal(pPager)
return rc;
}
/*
** Sync the database file for the pager pPager. zSuper points to the name
** of a super-journal file that should be written into the individual
** journal file. zSuper may be NULL, which is interpreted as no
** super-journal (a single database transaction).
**
** This routine ensures that:
**
** * The database file change-counter is updated,
** * the journal is synced (unless the atomic-write optimization is used),
** * all dirty pages are written to the database file,
** * the database file is truncated (if required), and
** * the database file synced.
**
** The only thing that remains to commit the transaction is to finalize
** (delete, truncate or zero the first part of) the journal file (or
** delete the super-journal file if specified).
**
** Note that if zSuper==NULL, this does not overwrite a previous value
** passed to an sqlite3PagerCommitPhaseOne() call.
**
** If the final parameter - noSync - is true, then the database file itself
** is not synced. The caller must call sqlite3PagerSync() directly to
** sync the database file before calling CommitPhaseTwo() to delete the
** journal file in this case.
*/
SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(
Pager *pPager, /* Pager object */
const char *zSuper, /* If not NULL, the super-journal name */
int noSync /* True to omit the xSync on the db file */
){
int rc = SQLITE_OK; /* Return code */
assert( pPager->eState==PAGER_WRITER_LOCKED
|| pPager->eState==PAGER_WRITER_CACHEMOD
|| pPager->eState==PAGER_WRITER_DBMOD
|| pPager->eState==PAGER_ERROR
);
assert( assert_pager_state(pPager) );
/* If a prior error occurred, report that error again. */
if( NEVER(pPager->errCode) ) return pPager->errCode;
/* Provide the ability to easily simulate an I/O error during testing */
if( sqlite3FaultSim(400) ) return SQLITE_IOERR;
PAGERTRACE(("DATABASE SYNC: File=%s zSuper=%s nSize=%d\n",
pPager->zFilename, zSuper, pPager->dbSize));
/* If no database changes have been made, return early. */
if( pPager->eState<PAGER_WRITER_CACHEMOD ) return SQLITE_OK;
assert( MEMDB==0 || pPager->tempFile );
assert( isOpen(pPager->fd) || pPager->tempFile );
if( 0==pagerFlushOnCommit(pPager, 1) ){
/* If this is an in-memory db, or no pages have been written to, or this
** function has already been called, it is mostly a no-op. However, any
** backup in progress needs to be restarted. */
sqlite3BackupRestart(pPager->pBackup);
}else{
PgHdr *pList;
if( pagerUseWal(pPager) ){
PgHdr *pPageOne = 0;
pList = sqlite3PcacheDirtyList(pPager->pPCache);
if( pList==0 ){
/* Must have at least one page for the WAL commit flag.
** Ticket [2d1a5c67dfc2363e44f29d9bbd57f] 2011-05-18 */
rc = sqlite3PagerGet(pPager, 1, &pPageOne, 0);
pList = pPageOne;
pList->pDirty = 0;
}
assert( rc==SQLITE_OK );
if( ALWAYS(pList) ){
rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1);
}
sqlite3PagerUnref(pPageOne);
if( rc==SQLITE_OK ){
sqlite3PcacheCleanAll(pPager->pPCache);
}
}else{
/* The bBatch boolean is true if the batch-atomic-write commit method
** should be used. No rollback journal is created if batch-atomic-write
** is enabled.
*/
#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
sqlite3_file *fd = pPager->fd;
int bBatch = zSuper==0 /* An SQLITE_IOCAP_BATCH_ATOMIC commit */
&& (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)
&& !pPager->noSync
&& sqlite3JournalIsInMemory(pPager->jfd);
#else
# define bBatch 0
#endif
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
/* The following block updates the change-counter. Exactly how it
** does this depends on whether or not the atomic-update optimization
** was enabled at compile time, and if this transaction meets the
** runtime criteria to use the operation:
**
** * The file-system supports the atomic-write property for
** blocks of size page-size, and
** * This commit is not part of a multi-file transaction, and
** * Exactly one page has been modified and store in the journal file.
**
** If the optimization was not enabled at compile time, then the
** pager_incr_changecounter() function is called to update the change
** counter in 'indirect-mode'. If the optimization is compiled in but
** is not applicable to this transaction, call sqlite3JournalCreate()
** to make sure the journal file has actually been created, then call
** pager_incr_changecounter() to update the change-counter in indirect
** mode.
**
** Otherwise, if the optimization is both enabled and applicable,
** then call pager_incr_changecounter() to update the change-counter
** in 'direct' mode. In this case the journal file will never be
** created for this transaction.
*/
if( state==PAGER_OPEN ){
rc = sqlite3PagerSharedLock(pPager);
}
if( pPager->eState==PAGER_READER ){
assert( rc==SQLITE_OK );
rc = pagerLockDb(pPager, RESERVED_LOCK);
}
if( rc==SQLITE_OK ){
sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
}
if( rc==SQLITE_OK && state==PAGER_READER ){
pagerUnlockDb(pPager, SHARED_LOCK);
}else if( state==PAGER_OPEN ){
pager_unlock(pPager);
}
assert( state==pPager->eState );
}
}else if( eMode==PAGER_JOURNALMODE_OFF || eMode==PAGER_JOURNALMODE_MEMORY ){
sqlite3OsClose(pPager->jfd);
}
}
/* Return the new journal mode */
return (int)pPager->journalMode;
}
/*
** Return the current journal mode.
*/
SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager *pPager){
return (int)pPager->journalMode;
}
/*
** Return TRUE if the pager is in a state where it is OK to change the
** journalmode. Journalmode changes can only happen when the database
** is unmodified.
*/
SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager *pPager){
assert( assert_pager_state(pPager) );
if( pPager->eState>=PAGER_WRITER_CACHEMOD ) return 0;
if( NEVER(isOpen(pPager->jfd) && pPager->journalOff>0) ) return 0;
return 1;
}
/*
** Get/set the size-limit used for persistent journal files.
**
** Setting the size limit to -1 means no limit is enforced.
** An attempt to set a limit smaller than -1 is a no-op.
*/
SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *pPager, i64 iLimit){
if( iLimit>=-1 ){
pPager->journalSizeLimit = iLimit;
sqlite3WalLimit(pPager->pWal, iLimit);
}
return pPager->journalSizeLimit;
}
/*
** Return a pointer to the pPager->pBackup variable. The backup module
** in backup.c maintains the content of this variable. This module
** uses it opaquely as an argument to sqlite3BackupRestart() and
** sqlite3BackupUpdate() only.
*/
SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
return &pPager->pBackup;
}
#ifndef SQLITE_OMIT_VACUUM
/*
** Unless this is an in-memory or temporary database, clear the pager cache.
*/
SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){
assert( MEMDB==0 || pPager->tempFile );
if( pPager->tempFile==0 ) pager_reset(pPager);
}
#endif
#ifndef SQLITE_OMIT_WAL
/*
** This function is called when the user invokes "PRAGMA wal_checkpoint",
** "PRAGMA wal_blocking_checkpoint" or calls the sqlite3_wal_checkpoint()
** or wal_blocking_checkpoint() API functions.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
SQLITE_PRIVATE int sqlite3PagerCheckpoint(
Pager *pPager, /* Checkpoint on this pager */
sqlite3 *db, /* Db handle used to check for interrupts */
int eMode, /* Type of checkpoint */
int *pnLog, /* OUT: Final number of frames in log */
int *pnCkpt /* OUT: Final number of checkpointed frames */
){
int rc = SQLITE_OK;
if( pPager->pWal==0 && pPager->journalMode==PAGER_JOURNALMODE_WAL ){
/* This only happens when a database file is zero bytes in size opened and
** then "PRAGMA journal_mode=WAL" is run and then sqlite3_wal_checkpoint()
** is invoked without any intervening transactions. We need to start
** a transaction to initialize pWal. The PRAGMA table_list statement is
** used for this since it starts transactions on every database file,
** including all ATTACHed databases. This seems expensive for a single
** sqlite3_wal_checkpoint() call, but it happens very rarely.
** https://sqlite.org/forum/forumpost/fd0f19d229156939
*/
sqlite3_exec(db, "PRAGMA table_list",0,0,0);
}
if( pPager->pWal ){
rc = sqlite3WalCheckpoint(pPager->pWal, db, eMode,
(eMode<=SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),
pPager->pBusyHandlerArg,
pPager->walSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
pnLog, pnCkpt
);
}
return rc;
}
SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager){
return sqlite3WalCallback(pPager->pWal);
}
/*
** Return true if the underlying VFS for the given pager supports the
** primitives necessary for write-ahead logging.
u8 *apOvfl[4]; /* Pointers to the body of overflow cells */
BtShared *pBt; /* Pointer to BtShared that this page is part of */
u8 *aData; /* Pointer to disk image of the page data */
u8 *aDataEnd; /* One byte past the end of the entire page - not just
** the usable space, the entire page. Used to prevent
** corruption-induced buffer overflow. */
u8 *aCellIdx; /* The cell index area */
u8 *aDataOfst; /* Same as aData for leaves. aData+4 for interior */
DbPage *pDbPage; /* Pager page handle */
u16 (*xCellSize)(MemPage*,u8*); /* cellSizePtr method */
void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */
};
/*
** A linked list of the following structures is stored at BtShared.pLock.
** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor
** is opened on the table with root page BtShared.iTable. Locks are removed
** from this list when a transaction is committed or rolled back, or when
** a btree handle is closed.
*/
struct BtLock {
Btree *pBtree; /* Btree handle holding this lock */
Pgno iTable; /* Root page of table */
u8 eLock; /* READ_LOCK or WRITE_LOCK */
BtLock *pNext; /* Next in BtShared.pLock list */
};
/* Candidate values for BtLock.eLock */
#define READ_LOCK 1
#define WRITE_LOCK 2
/* A Btree handle
**
** A database connection contains a pointer to an instance of
** this object for every database file that it has open. This structure
** is opaque to the database connection. The database connection cannot
** see the internals of this structure and only deals with pointers to
** this structure.
**
** For some database files, the same underlying database cache might be
** shared between multiple connections. In that case, each connection
** has it own instance of this object. But each instance of this object
** points to the same BtShared object. The database cache and the
** schema associated with the database file are all contained within
** the BtShared object.
**
** All fields in this structure are accessed under sqlite3.mutex.
** The pBt pointer itself may not be changed while there exists cursors
** in the referenced BtShared that point back to this Btree since those
** cursors have to go through this Btree to find their BtShared and
** they often do so without holding sqlite3.mutex.
*/
struct Btree {
sqlite3 *db; /* The database connection holding this btree */
BtShared *pBt; /* Sharable content of this btree */
u8 inTrans; /* TRANS_NONE, TRANS_READ or TRANS_WRITE */
u8 sharable; /* True if we can share pBt with another db */
u8 locked; /* True if db currently has pBt locked */
u8 hasIncrblobCur; /* True if there are one or more Incrblob cursors */
int wantToLock; /* Number of nested calls to sqlite3BtreeEnter() */
int nBackup; /* Number of backup operations reading this btree */
u32 iBDataVersion; /* Combines with pBt->pPager->iDataVersion */
Btree *pNext; /* List of other sharable Btrees from the same db */
Btree *pPrev; /* Back pointer of the same list */
#ifdef SQLITE_DEBUG
u64 nSeek; /* Calls to sqlite3BtreeMovetoUnpacked() */
#endif
#ifndef SQLITE_OMIT_SHARED_CACHE
BtLock lock; /* Object used to lock page 1 */
#endif
};
/*
** Btree.inTrans may take one of the following values.
**
** If the shared-data extension is enabled, there may be multiple users
** of the Btree structure. At most one of these may open a write transaction,
** but any number may have active read transactions.
**
** These values must match SQLITE_TXN_NONE, SQLITE_TXN_READ, and
** SQLITE_TXN_WRITE
*/
#define TRANS_NONE 0
#define TRANS_READ 1
#define TRANS_WRITE 2
#if TRANS_NONE!=SQLITE_TXN_NONE
# error wrong numeric code for no-transaction
#endif
#if TRANS_READ!=SQLITE_TXN_READ
# error wrong numeric code for read-transaction
#endif
#if TRANS_WRITE!=SQLITE_TXN_WRITE
# error wrong numeric code for write-transaction
#endif
/*
** An instance of this object represents a single database file.
**
** A single database file can be in use at the same time by two
** or more database connections. When two or more connections are
** sharing the same database file, each connection has it own
** private Btree object for the file and each of those Btrees points
** to this one BtShared object. BtShared.nRef is the number of
** connections currently sharing this database file.
**
** Fields in this structure are accessed under the BtShared.mutex
** mutex, except for nRef and pNext which are accessed under the
** global SQLITE_MUTEX_STATIC_MAIN mutex. The pPager field
** may not be modified once it is initially set as long as nRef>0.
** The pSchema field may be set once under BtShared.mutex and
** thereafter is unchanged as long as nRef>0.
**
** isPending:
**
** If a BtShared client fails to obtain a write-lock on a database
** table (because there exists one or more read-locks on the table),
** the shared-cache enters 'pending-lock' state and isPending is
** set to true.
**
** The page size must be a power of 2 between 512 and 65536. If the page
** size supplied does not meet this constraint then the page size is not
** changed.
**
** Page sizes are constrained to be a power of two so that the region
** of the database file used for locking (beginning at PENDING_BYTE,
** the first byte past the 1GB boundary, 0x40000000) needs to occur
** at the beginning of a page.
**
** If parameter nReserve is less than zero, then the number of reserved
** bytes per page is left unchanged.
**
** If the iFix!=0 then the BTS_PAGESIZE_FIXED flag is set so that the page size
** and autovacuum mode can no longer be changed.
*/
SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
int rc = SQLITE_OK;
int x;
BtShared *pBt = p->pBt;
assert( nReserve>=0 && nReserve<=255 );
sqlite3BtreeEnter(p);
pBt->nReserveWanted = (u8)nReserve;
x = pBt->pageSize - pBt->usableSize;
if( x==nReserve && (pageSize==0 || (u32)pageSize==pBt->pageSize) ){
sqlite3BtreeLeave(p);
return SQLITE_OK;
}
if( nReserve<x ) nReserve = x;
if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
sqlite3BtreeLeave(p);
return SQLITE_READONLY;
}
assert( nReserve>=0 && nReserve<=255 );
if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
((pageSize-1)&pageSize)==0 ){
assert( (pageSize & 7)==0 );
assert( !pBt->pCursor );
if( nReserve>32 && pageSize==512 ) pageSize = 1024;
pBt->pageSize = (u32)pageSize;
freeTempSpace(pBt);
}
rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);
pBt->usableSize = pBt->pageSize - (u16)nReserve;
if( iFix ) pBt->btsFlags |= BTS_PAGESIZE_FIXED;
sqlite3BtreeLeave(p);
return rc;
}
/*
** Return the currently defined page size
*/
SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree *p){
return p->pBt->pageSize;
}
/*
** This function is similar to sqlite3BtreeGetReserve(), except that it
** may only be called if it is guaranteed that the b-tree mutex is already
** held.
**
** This is useful in one special case in the backup API code where it is
** known that the shared b-tree mutex is held, but the mutex on the
** database handle that owns *p is not. In this case if sqlite3BtreeEnter()
** were to be called, it might collide with some other operation on the
** database handle that owns *p, causing undefined behavior.
*/
SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p){
int n;
assert( sqlite3_mutex_held(p->pBt->mutex) );
n = p->pBt->pageSize - p->pBt->usableSize;
return n;
}
/*
** Return the number of bytes of space at the end of every page that
** are intentionally left unused. This is the "reserved" space that is
** sometimes used by extensions.
**
** The value returned is the larger of the current reserve size and
** the latest reserve size requested by SQLITE_FILECTRL_RESERVE_BYTES.
** The amount of reserve can only grow - never shrink.
*/
SQLITE_PRIVATE int sqlite3BtreeGetRequestedReserve(Btree *p){
int n1, n2;
sqlite3BtreeEnter(p);
n1 = (int)p->pBt->nReserveWanted;
n2 = sqlite3BtreeGetReserveNoMutex(p);
sqlite3BtreeLeave(p);
return n1>n2 ? n1 : n2;
}
/*
** Set the maximum page count for a database if mxPage is positive.
** No changes are made if mxPage is 0 or negative.
** Regardless of the value of mxPage, return the maximum page count.
*/
SQLITE_PRIVATE Pgno sqlite3BtreeMaxPageCount(Btree *p, Pgno mxPage){
Pgno n;
sqlite3BtreeEnter(p);
n = sqlite3PagerMaxPageCount(p->pBt->pPager, mxPage);
sqlite3BtreeLeave(p);
return n;
}
/*
** Change the values for the BTS_SECURE_DELETE and BTS_OVERWRITE flags:
**
** newFlag==0 Both BTS_SECURE_DELETE and BTS_OVERWRITE are cleared
** newFlag==1 BTS_SECURE_DELETE set and BTS_OVERWRITE is cleared
** newFlag==2 BTS_SECURE_DELETE cleared and BTS_OVERWRITE is set
** newFlag==(-1) No changes
**
** This routine acts as a query if newFlag is less than zero
**
** With BTS_OVERWRITE set, deleted content is overwritten by zeros, but
** freelist leaf pages are not written back to the database. Thus in-page
** deleted content is cleared, but freelist deleted content is not.
**
** With BTS_SECURE_DELETE, operation is like BTS_OVERWRITE with the addition
** that freelist leaf pages are written back into the database, increasing
/*
** Return the full pathname of the underlying database file. Return
** an empty string if the database is in-memory or a TEMP database.
**
** The pager filename is invariant as long as the pager is
** open so it is safe to access without the BtShared mutex.
*/
SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *p){
assert( p->pBt->pPager!=0 );
return sqlite3PagerFilename(p->pBt->pPager, 1);
}
/*
** Return the pathname of the journal file for this database. The return
** value of this routine is the same regardless of whether the journal file
** has been created or not.
**
** The pager journal filename is invariant as long as the pager is
** open so it is safe to access without the BtShared mutex.
*/
SQLITE_PRIVATE const char *sqlite3BtreeGetJournalname(Btree *p){
assert( p->pBt->pPager!=0 );
return sqlite3PagerJournalname(p->pBt->pPager);
}
/*
** Return one of SQLITE_TXN_NONE, SQLITE_TXN_READ, or SQLITE_TXN_WRITE
** to describe the current transaction state of Btree p.
*/
SQLITE_PRIVATE int sqlite3BtreeTxnState(Btree *p){
assert( p==0 || sqlite3_mutex_held(p->db->mutex) );
return p ? p->inTrans : 0;
}
#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on the Btree passed as the first argument.
**
** Return SQLITE_LOCKED if this or any other connection has an open
** transaction on the shared-cache the argument Btree is connected to.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
SQLITE_PRIVATE int sqlite3BtreeCheckpoint(Btree *p, int eMode, int *pnLog, int *pnCkpt){
int rc = SQLITE_OK;
if( p ){
BtShared *pBt = p->pBt;
sqlite3BtreeEnter(p);
if( pBt->inTransaction!=TRANS_NONE ){
rc = SQLITE_LOCKED;
}else{
rc = sqlite3PagerCheckpoint(pBt->pPager, p->db, eMode, pnLog, pnCkpt);
}
sqlite3BtreeLeave(p);
}
return rc;
}
#endif
/*
** Return true if there is currently a backup running on Btree p.
*/
SQLITE_PRIVATE int sqlite3BtreeIsInBackup(Btree *p){
assert( p );
assert( sqlite3_mutex_held(p->db->mutex) );
return p->nBackup!=0;
}
/*
** This function returns a pointer to a blob of memory associated with
** a single shared-btree. The memory is used by client code for its own
** purposes (for example, to store a high-level schema associated with
** the shared-btree). The btree layer manages reference counting issues.
**
** The first time this is called on a shared-btree, nBytes bytes of memory
** are allocated, zeroed, and returned to the caller. For each subsequent
** call the nBytes parameter is ignored and a pointer to the same blob
** of memory returned.
**
** If the nBytes parameter is 0 and the blob of memory has not yet been
** allocated, a null pointer is returned. If the blob has already been
** allocated, it is returned as normal.
**
** Just before the shared-btree is closed, the function passed as the
** xFree argument when the memory allocation was made is invoked on the
** blob of allocated memory. The xFree function should not call sqlite3_free()
** on the memory, the btree layer does that.
*/
SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *p, int nBytes, void(*xFree)(void *)){
BtShared *pBt = p->pBt;
assert( nBytes==0 || nBytes==sizeof(Schema) );
sqlite3BtreeEnter(p);
if( !pBt->pSchema && nBytes ){
pBt->pSchema = sqlite3DbMallocZero(0, nBytes);
pBt->xFreeSchema = xFree;
}
sqlite3BtreeLeave(p);
return pBt->pSchema;
}
/*
** Return SQLITE_LOCKED_SHAREDCACHE if another user of the same shared
** btree as the argument handle holds an exclusive lock on the
** sqlite_schema table. Otherwise SQLITE_OK.
*/
SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *p){
int rc;
UNUSED_PARAMETER(p); /* only used in DEBUG builds */
assert( sqlite3_mutex_held(p->db->mutex) );
sqlite3BtreeEnter(p);
rc = querySharedCacheTableLock(p, SCHEMA_ROOT, READ_LOCK);
assert( rc==SQLITE_OK || rc==SQLITE_LOCKED_SHAREDCACHE );
sqlite3BtreeLeave(p);
return rc;
}
#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** Obtain a lock on the table whose root page is iTab. The
** lock is a write lock if isWritelock is true or a read lock
}
}
}
}
pBt->btsFlags &= ~BTS_NO_WAL;
return rc;
}
/*
** Return true if the cursor has a hint specified. This routine is
** only used from within assert() statements
*/
SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor *pCsr, unsigned int mask){
return (pCsr->hints & mask)!=0;
}
/*
** Return true if the given Btree is read-only.
*/
SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *p){
return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
}
/*
** Return the size of the header added to each page by this module.
*/
SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
/*
** If no transaction is active and the database is not a temp-db, clear
** the in-memory pager cache.
*/
SQLITE_PRIVATE void sqlite3BtreeClearCache(Btree *p){
BtShared *pBt = p->pBt;
if( pBt->inTransaction==TRANS_NONE ){
sqlite3PagerClearCache(pBt->pPager);
}
}
#if !defined(SQLITE_OMIT_SHARED_CACHE)
/*
** Return true if the Btree passed as the only argument is sharable.
*/
SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){
return p->sharable;
}
/*
** Return the number of connections to the BtShared object accessed by
** the Btree handle passed as the only argument. For private caches
** this is always 1. For shared caches it may be 1 or greater.
*/
SQLITE_PRIVATE int sqlite3BtreeConnectionCount(Btree *p){
testcase( p->sharable );
return p->pBt->nRef;
}
#endif
/************** End of btree.c ***********************************************/
/************** Begin file backup.c ******************************************/
/*
** 2009 January 28
**
** 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 file contains the implementation of the sqlite3_backup_XXX()
** API functions and the related features.
*/
/* #include "sqliteInt.h" */
/* #include "btreeInt.h" */
/*
** Structure allocated for each backup operation.
*/
struct sqlite3_backup {
sqlite3* pDestDb; /* Destination database handle */
Btree *pDest; /* Destination b-tree file */
u32 iDestSchema; /* Original schema cookie in destination */
int bDestLocked; /* True once a write-transaction is open on pDest */
Pgno iNext; /* Page number of the next source page to copy */
sqlite3* pSrcDb; /* Source database handle */
Btree *pSrc; /* Source b-tree file */
int rc; /* Backup process error code */
/* These two variables are set by every call to backup_step(). They are
** read by calls to backup_remaining() and backup_pagecount().
*/
Pgno nRemaining; /* Number of pages left to copy */
Pgno nPagecount; /* Total number of pages to copy */
int isAttached; /* True once backup has been registered with pager */
sqlite3_backup *pNext; /* Next backup associated with source pager */
};
/*
** THREAD SAFETY NOTES:
**
** Once it has been created using backup_init(), a single sqlite3_backup
** structure may be accessed via two groups of thread-safe entry points:
**
** * Via the sqlite3_backup_XXX() API function backup_step() and
** backup_finish(). Both these functions obtain the source database
** handle mutex and the mutex associated with the source BtShared
** structure, in that order.
**
** * Via the BackupUpdate() and BackupRestart() functions, which are
** invoked by the pager layer to report various state changes in
** the page cache associated with the source database. The mutex
** associated with the source database BtShared structure will always
** be held when either of these functions are invoked.
**
** The other sqlite3_backup_XXX() API functions, backup_remaining() and
** backup_pagecount() are not thread-safe functions. If they are called
** while some other thread is calling backup_step() or backup_finish(),
** the values returned may be invalid. There is no way for a call to
** BackupUpdate() or BackupRestart() to interfere with backup_remaining()
** or backup_pagecount().
**
** Depending on the SQLite configuration, the database handles and/or
** the Btree objects may have their own mutexes that require locking.
** Non-sharable Btrees (in-memory databases for example), do not have
** associated mutexes.
*/
/*
** Return a pointer corresponding to database zDb (i.e. "main", "temp")
** in connection handle pDb. If such a database cannot be found, return
** a NULL pointer and write an error message to pErrorDb.
**
** If the "temp" database is requested, it may need to be opened by this
** function. If an error occurs while doing so, return 0 and write an
** error message to pErrorDb.
*/
static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
int i = sqlite3FindDbName(pDb, zDb);
if( i==1 ){
Parse sParse;
int rc = 0;
sqlite3ParseObjectInit(&sParse,pDb);
if( sqlite3OpenTempDatabase(&sParse) ){
sqlite3ErrorWithMsg(pErrorDb, sParse.rc, "%s", sParse.zErrMsg);
rc = SQLITE_ERROR;
}
sqlite3DbFree(pErrorDb, sParse.zErrMsg);
sqlite3ParseObjectReset(&sParse);
if( rc ){
return 0;
}
}
if( i<0 ){
sqlite3ErrorWithMsg(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);
return 0;
}
return pDb->aDb[i].pBt;
}
/*
** Attempt to set the page size of the destination to match the page size
** of the source.
*/
static int setDestPgsz(sqlite3_backup *p){
int rc;
rc = sqlite3BtreeSetPageSize(p->pDest,sqlite3BtreeGetPageSize(p->pSrc),0,0);
return rc;
}
/*
** Check that there is no open read-transaction on the b-tree passed as the
** second argument. If there is not, return SQLITE_OK. Otherwise, if there
** is an open read-transaction, return SQLITE_ERROR and leave an error
** message in database handle db.
*/
static int checkReadTransaction(sqlite3 *db, Btree *p){
if( sqlite3BtreeTxnState(p)!=SQLITE_TXN_NONE ){
sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
return SQLITE_ERROR;
}
return SQLITE_OK;
}
/*
** Create an sqlite3_backup process to copy the contents of zSrcDb from
** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
** a pointer to the new sqlite3_backup object.
**
** If an error occurs, NULL is returned and an error code and error message
** stored in database handle pDestDb.
*/
SQLITE_API sqlite3_backup *sqlite3_backup_init(
sqlite3* pDestDb, /* Database to write to */
const char *zDestDb, /* Name of database within pDestDb */
sqlite3* pSrcDb, /* Database connection to read from */
const char *zSrcDb /* Name of database within pSrcDb */
){
sqlite3_backup *p; /* Value to return */
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(pSrcDb)||!sqlite3SafetyCheckOk(pDestDb) ){
(void)SQLITE_MISUSE_BKPT;
return 0;
}
#endif
/* Lock the source database handle. The destination database
** handle is not locked in this routine, but it is locked in
** sqlite3_backup_step(). The user is required to ensure that no
** other thread accesses the destination handle for the duration
** of the backup operation. Any attempt to use the destination
** database connection while a backup is in progress may cause
** a malfunction or a deadlock.
*/
sqlite3_mutex_enter(pSrcDb->mutex);
sqlite3_mutex_enter(pDestDb->mutex);
if( pSrcDb==pDestDb ){
sqlite3ErrorWithMsg(
pDestDb, SQLITE_ERROR, "source and destination must be distinct"
);
p = 0;
}else {
/* Allocate space for a new sqlite3_backup object...
** EVIDENCE-OF: R-64852-21591 The sqlite3_backup object is created by a
** call to sqlite3_backup_init() and is destroyed by a call to
** sqlite3_backup_finish(). */
p = (sqlite3_backup *)sqlite3MallocZero(sizeof(sqlite3_backup));
if( !p ){
sqlite3Error(pDestDb, SQLITE_NOMEM_BKPT);
}
}
/* If the allocation succeeded, populate the new object. */
if( p ){
p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);
p->pDest = findBtree(pDestDb, pDestDb, zDestDb);
p->pDestDb = pDestDb;
p->pSrcDb = pSrcDb;
p->iNext = 1;
p->isAttached = 0;
if( 0==p->pSrc || 0==p->pDest
|| checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK
){
/* One (or both) of the named databases did not exist or an OOM
** error was hit. Or there is a transaction open on the destination
** database. The error has already been written into the pDestDb
** handle. All that is left to do here is free the sqlite3_backup
** structure. */
sqlite3_free(p);
p = 0;
}
}
if( p ){
p->pSrc->nBackup++;
}
sqlite3_mutex_leave(pDestDb->mutex);
sqlite3_mutex_leave(pSrcDb->mutex);
return p;
}
/*
** Argument rc is an SQLite error code. Return true if this error is
** considered fatal if encountered during a backup operation. All errors
** are considered fatal except for SQLITE_BUSY and SQLITE_LOCKED.
*/
static int isFatalError(int rc){
return (rc!=SQLITE_OK && rc!=SQLITE_BUSY && ALWAYS(rc!=SQLITE_LOCKED));
}
/*
** Parameter zSrcData points to a buffer containing the data for
** page iSrcPg from the source database. Copy this data into the
** destination database.
*/
static int backupOnePage(
sqlite3_backup *p, /* Backup handle */
Pgno iSrcPg, /* Source database page to backup */
const u8 *zSrcData, /* Source database page data */
int bUpdate /* True for an update, false otherwise */
){
Pager * const pDestPager = sqlite3BtreePager(p->pDest);
const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
const int nCopy = MIN(nSrcPgsz, nDestPgsz);
const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;
int rc = SQLITE_OK;
i64 iOff;
assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );
assert( p->bDestLocked );
assert( !isFatalError(p->rc) );
assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
assert( zSrcData );
assert( nSrcPgsz==nDestPgsz || sqlite3PagerIsMemdb(pDestPager)==0 );
/* This loop runs once for each destination page spanned by the source
** page. For each iteration, variable iOff is set to the byte offset
** of the destination page.
*/
for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){
DbPage *pDestPg = 0;
Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;
if( iDest==PENDING_BYTE_PAGE(p->pDest->pBt) ) continue;
if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg, 0))
&& SQLITE_OK==(rc = sqlite3PagerWrite(pDestPg))
){
const u8 *zIn = &zSrcData[iOff%nSrcPgsz];
u8 *zDestData = sqlite3PagerGetData(pDestPg);
u8 *zOut = &zDestData[iOff%nDestPgsz];
/* Copy the data from the source page into the destination page.
** Then clear the Btree layer MemPage.isInit flag. Both this module
** and the pager code use this trick (clearing the first byte
** of the page 'extra' space to invalidate the Btree layers
** cached parse of the page). MemPage.isInit is marked
** "MUST BE FIRST" for this purpose.
*/
memcpy(zOut, zIn, nCopy);
((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;
if( iOff==0 && bUpdate==0 ){
sqlite3Put4byte(&zOut[28], sqlite3BtreeLastPage(p->pSrc));
}
}
sqlite3PagerUnref(pDestPg);
}
return rc;
}
/*
** If pFile is currently larger than iSize bytes, then truncate it to
** exactly iSize bytes. If pFile is not larger than iSize bytes, then
** this function is a no-op.
**
** Return SQLITE_OK if everything is successful, or an SQLite error
** code if an error occurs.
*/
static int backupTruncateFile(sqlite3_file *pFile, i64 iSize){
i64 iCurrent;
int rc = sqlite3OsFileSize(pFile, &iCurrent);
if( rc==SQLITE_OK && iCurrent>iSize ){
rc = sqlite3OsTruncate(pFile, iSize);
}
return rc;
}
/*
** Register this backup object with the associated source pager for
** callbacks when pages are changed or the cache invalidated.
*/
static void attachBackupObject(sqlite3_backup *p){
sqlite3_backup **pp;
assert( sqlite3BtreeHoldsMutex(p->pSrc) );
pp = sqlite3PagerBackupPtr(sqlite3BtreePager(p->pSrc));
p->pNext = *pp;
*pp = p;
p->isAttached = 1;
}
/*
** Copy nPage pages from the source b-tree to the destination.
*/
SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){
int rc;
int destMode; /* Destination journal mode */
int pgszSrc = 0; /* Source page size */
int pgszDest = 0; /* Destination page size */
#ifdef SQLITE_ENABLE_API_ARMOR
if( p==0 ) return SQLITE_MISUSE_BKPT;
#endif
sqlite3_mutex_enter(p->pSrcDb->mutex);
sqlite3BtreeEnter(p->pSrc);
if( p->pDestDb ){
sqlite3_mutex_enter(p->pDestDb->mutex);
}
rc = p->rc;
if( !isFatalError(rc) ){
Pager * const pSrcPager = sqlite3BtreePager(p->pSrc); /* Source pager */
Pager * const pDestPager = sqlite3BtreePager(p->pDest); /* Dest pager */
int ii; /* Iterator variable */
int nSrcPage = -1; /* Size of source db in pages */
int bCloseTrans = 0; /* True if src db requires unlocking */
/* If the source pager is currently in a write-transaction, return
** SQLITE_BUSY immediately.
*/
if( p->pDestDb && p->pSrc->pBt->inTransaction==TRANS_WRITE ){
rc = SQLITE_BUSY;
}else{
rc = SQLITE_OK;
}
/* If there is no open read-transaction on the source database, open
** one now. If a transaction is opened here, then it will be closed
** before this function exits.
*/
if( rc==SQLITE_OK && SQLITE_TXN_NONE==sqlite3BtreeTxnState(p->pSrc) ){
rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0);
bCloseTrans = 1;
}
/* If the destination database has not yet been locked (i.e. if this
** is the first call to backup_step() for the current backup operation),
** try to set its page size to the same as the source database. This
** is especially important on ZipVFS systems, as in that case it is
** not possible to create a database file that uses one page size by
** writing to it with another. */
if( p->bDestLocked==0 && rc==SQLITE_OK && setDestPgsz(p)==SQLITE_NOMEM ){
rc = SQLITE_NOMEM;
}
/* Lock the destination database, if it is not locked already. */
if( SQLITE_OK==rc && p->bDestLocked==0
&& SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2,
(int*)&p->iDestSchema))
){
p->bDestLocked = 1;
}
/* Do not allow backup if the destination database is in WAL mode
** and the page sizes are different between source and destination */
pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);
pgszDest = sqlite3BtreeGetPageSize(p->pDest);
destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest));
if( SQLITE_OK==rc
&& (destMode==PAGER_JOURNALMODE_WAL || sqlite3PagerIsMemdb(pDestPager))
&& pgszSrc!=pgszDest
){
rc = SQLITE_READONLY;
}
/* Now that there is a read-lock on the source database, query the
** source pager for the number of pages in the database.
*/
nSrcPage = (int)sqlite3BtreeLastPage(p->pSrc);
assert( nSrcPage>=0 );
for(ii=0; (nPage<0 || ii<nPage) && p->iNext<=(Pgno)nSrcPage && !rc; ii++){
const Pgno iSrcPg = p->iNext; /* Source page number */
if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){
DbPage *pSrcPg; /* Source page object */
rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg,PAGER_GET_READONLY);
if( rc==SQLITE_OK ){
rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);
sqlite3PagerUnref(pSrcPg);
}
}
p->iNext++;
}
if( rc==SQLITE_OK ){
p->nPagecount = nSrcPage;
p->nRemaining = nSrcPage+1-p->iNext;
if( p->iNext>(Pgno)nSrcPage ){
rc = SQLITE_DONE;
}else if( !p->isAttached ){
attachBackupObject(p);
}
}
/* Update the schema version field in the destination database. This
** is to make sure that the schema-version really does change in
** the case where the source and destination databases have the
** same schema version.
*/
if( rc==SQLITE_DONE ){
if( nSrcPage==0 ){
rc = sqlite3BtreeNewDb(p->pDest);
nSrcPage = 1;
}
if( rc==SQLITE_OK || rc==SQLITE_DONE ){
rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);
}
if( rc==SQLITE_OK ){
if( p->pDestDb ){
sqlite3ResetAllSchemasOfConnection(p->pDestDb);
}
if( destMode==PAGER_JOURNALMODE_WAL ){
rc = sqlite3BtreeSetVersion(p->pDest, 2);
}
}
if( rc==SQLITE_OK ){
int nDestTruncate;
/* Set nDestTruncate to the final number of pages in the destination
** database. The complication here is that the destination page
** size may be different to the source page size.
**
** If the source page size is smaller than the destination page size,
** round up. In this case the call to sqlite3OsTruncate() below will
** fix the size of the file. However it is important to call
** sqlite3PagerTruncateImage() here so that any pages in the
** destination file that lie beyond the nDestTruncate page mark are
** journalled by PagerCommitPhaseOne() before they are destroyed
** by the file truncation.
*/
assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) );
assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) );
if( pgszSrc<pgszDest ){
int ratio = pgszDest/pgszSrc;
nDestTruncate = (nSrcPage+ratio-1)/ratio;
if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){
nDestTruncate--;
}
}else{
nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
** two extra things may need to happen:
**
** * The destination may need to be truncated, and
**
** * Data stored on the pages immediately following the
** pending-byte page in the source database may need to be
** copied into the destination database.
*/
const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
Pgno iPg;
int nDstPage;
i64 iOff;
i64 iEnd;
assert( pFile );
assert( nDestTruncate==0
|| (i64)nDestTruncate*(i64)pgszDest >= iSize || (
nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)
&& iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
));
/* This block ensures that all data required to recreate the original
** database has been stored in the journal for pDestPager and the
** journal synced to disk. So at this point we may safely modify
** the database file in any way, knowing that if a power failure
** occurs, the original database will be reconstructed from the
** journal file. */
sqlite3PagerPagecount(pDestPager, &nDstPage);
for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){
if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){
DbPage *pPg;
rc = sqlite3PagerGet(pDestPager, iPg, &pPg, 0);
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite(pPg);
sqlite3PagerUnref(pPg);
}
}
}
if( rc==SQLITE_OK ){
rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
}
/* Write the extra pages and truncate the database file as required */
iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
for(
iOff=PENDING_BYTE+pgszSrc;
rc==SQLITE_OK && iOff<iEnd;
iOff+=pgszSrc
){
PgHdr *pSrcPg = 0;
const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);
rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg, 0);
if( rc==SQLITE_OK ){
u8 *zData = sqlite3PagerGetData(pSrcPg);
rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);
}
sqlite3PagerUnref(pSrcPg);
}
if( rc==SQLITE_OK ){
rc = backupTruncateFile(pFile, iSize);
}
/* Sync the database file to disk. */
if( rc==SQLITE_OK ){
rc = sqlite3PagerSync(pDestPager, 0);
}
}else{
sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
}
/* Finish committing the transaction to the destination database. */
if( SQLITE_OK==rc
&& SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0))
){
rc = SQLITE_DONE;
}
}
}
/* If bCloseTrans is true, then this function opened a read transaction
** on the source database. Close the read transaction here. There is
** no need to check the return values of the btree methods here, as
** "committing" a read-only transaction cannot fail.
*/
if( bCloseTrans ){
TESTONLY( int rc2 );
TESTONLY( rc2 = ) sqlite3BtreeCommitPhaseOne(p->pSrc, 0);
TESTONLY( rc2 |= ) sqlite3BtreeCommitPhaseTwo(p->pSrc, 0);
assert( rc2==SQLITE_OK );
}
if( rc==SQLITE_IOERR_NOMEM ){
rc = SQLITE_NOMEM_BKPT;
}
p->rc = rc;
}
if( p->pDestDb ){
sqlite3_mutex_leave(p->pDestDb->mutex);
}
sqlite3BtreeLeave(p->pSrc);
sqlite3_mutex_leave(p->pSrcDb->mutex);
return rc;
}
/*
** Release all resources associated with an sqlite3_backup* handle.
*/
SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){
sqlite3_backup **pp; /* Ptr to head of pagers backup list */
sqlite3 *pSrcDb; /* Source database connection */
int rc; /* Value to return */
/* Enter the mutexes */
if( p==0 ) return SQLITE_OK;
pSrcDb = p->pSrcDb;
sqlite3_mutex_enter(pSrcDb->mutex);
sqlite3BtreeEnter(p->pSrc);
if( p->pDestDb ){
sqlite3_mutex_enter(p->pDestDb->mutex);
}
/* Detach this backup from the source pager. */
if( p->pDestDb ){
p->pSrc->nBackup--;
}
if( p->isAttached ){
pp = sqlite3PagerBackupPtr(sqlite3BtreePager(p->pSrc));
assert( pp!=0 );
while( *pp!=p ){
pp = &(*pp)->pNext;
assert( pp!=0 );
}
*pp = p->pNext;
}
/* If a transaction is still open on the Btree, roll it back. */
sqlite3BtreeRollback(p->pDest, SQLITE_OK, 0);
/* Set the error code of the destination database handle. */
rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
if( p->pDestDb ){
sqlite3Error(p->pDestDb, rc);
/* Exit the mutexes and free the backup context structure. */
sqlite3LeaveMutexAndCloseZombie(p->pDestDb);
}
sqlite3BtreeLeave(p->pSrc);
if( p->pDestDb ){
/* EVIDENCE-OF: R-64852-21591 The sqlite3_backup object is created by a
** call to sqlite3_backup_init() and is destroyed by a call to
** sqlite3_backup_finish(). */
sqlite3_free(p);
}
sqlite3LeaveMutexAndCloseZombie(pSrcDb);
return rc;
}
/*
** Return the number of pages still to be backed up as of the most recent
** call to sqlite3_backup_step().
*/
SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p){
#ifdef SQLITE_ENABLE_API_ARMOR
if( p==0 ){
(void)SQLITE_MISUSE_BKPT;
return 0;
}
#endif
return p->nRemaining;
}
/*
** Return the total number of pages in the source database as of the most
** recent call to sqlite3_backup_step().
*/
SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p){
#ifdef SQLITE_ENABLE_API_ARMOR
if( p==0 ){
(void)SQLITE_MISUSE_BKPT;
return 0;
}
#endif
return p->nPagecount;
}
/*
** This function is called after the contents of page iPage of the
** source database have been modified. If page iPage has already been
** copied into the destination database, then the data written to the
** destination is now invalidated. The destination copy of iPage needs
** to be updated with the new data before the backup operation is
** complete.
**
** It is assumed that the mutex associated with the BtShared object
** corresponding to the source database is held when this function is
** called.
*/
static SQLITE_NOINLINE void backupUpdate(
sqlite3_backup *p,
Pgno iPage,
const u8 *aData
){
assert( p!=0 );
do{
assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );
if( !isFatalError(p->rc) && iPage<p->iNext ){
/* The backup process p has already copied page iPage. But now it
** has been modified by a transaction on the source pager. Copy
** the new data into the backup.
*/
int rc;
assert( p->pDestDb );
sqlite3_mutex_enter(p->pDestDb->mutex);
rc = backupOnePage(p, iPage, aData, 1);
sqlite3_mutex_leave(p->pDestDb->mutex);
assert( rc!=SQLITE_BUSY && rc!=SQLITE_LOCKED );
if( rc!=SQLITE_OK ){
p->rc = rc;
}
}
}while( (p = p->pNext)!=0 );
}
SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){
if( pBackup ) backupUpdate(pBackup, iPage, aData);
}
/*
** Restart the backup process. This is called when the pager layer
** detects that the database has been modified by an external database
** connection. In this case there is no way of knowing which of the
** pages that have been copied into the destination database are still
** valid and which are not, so the entire process needs to be restarted.
**
** It is assumed that the mutex associated with the BtShared object
** corresponding to the source database is held when this function is
** called.
*/
SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *pBackup){
sqlite3_backup *p; /* Iterator variable */
for(p=pBackup; p; p=p->pNext){
assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );
p->iNext = 1;
}
}
#ifndef SQLITE_OMIT_VACUUM
/*
** Copy the complete content of pBtFrom into pBtTo. A transaction
** must be active for both files.
**
** The size of file pTo may be reduced by this operation. If anything
** goes wrong, the transaction on pTo is rolled back. If successful, the
** transaction is committed before returning.
*/
SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
int rc;
sqlite3_file *pFd; /* File descriptor for database pTo */
sqlite3_backup b;
sqlite3BtreeEnter(pTo);
sqlite3BtreeEnter(pFrom);
assert( sqlite3BtreeTxnState(pTo)==SQLITE_TXN_WRITE );
pFd = sqlite3PagerFile(sqlite3BtreePager(pTo));
if( pFd->pMethods ){
i64 nByte = sqlite3BtreeGetPageSize(pFrom)*(i64)sqlite3BtreeLastPage(pFrom);
rc = sqlite3OsFileControl(pFd, SQLITE_FCNTL_OVERWRITE, &nByte);
if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
if( rc ) goto copy_finished;
}
/* Set up an sqlite3_backup object. sqlite3_backup.pDestDb must be set
** to 0. This is used by the implementations of sqlite3_backup_step()
** and sqlite3_backup_finish() to detect that they are being called
** from this function, not directly by the user.
*/
memset(&b, 0, sizeof(b));
b.pSrcDb = pFrom->db;
b.pSrc = pFrom;
b.pDest = pTo;
b.iNext = 1;
/* 0x7FFFFFFF is the hard limit for the number of pages in a database
** file. By passing this as the number of pages to copy to
** sqlite3_backup_step(), we can guarantee that the copy finishes
** within a single call (unless an error occurs). The assert() statement
** checks this assumption - (p->rc) should be set to either SQLITE_DONE
** or an error code. */
sqlite3_backup_step(&b, 0x7FFFFFFF);
assert( b.rc!=SQLITE_OK );
rc = sqlite3_backup_finish(&b);
if( rc==SQLITE_OK ){
pTo->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;
}else{
sqlite3PagerClearCache(sqlite3BtreePager(b.pDest));
}
assert( sqlite3BtreeTxnState(pTo)!=SQLITE_TXN_WRITE );
copy_finished:
sqlite3BtreeLeave(pFrom);
sqlite3BtreeLeave(pTo);
return rc;
}
#endif /* SQLITE_OMIT_VACUUM */
/************** End of backup.c **********************************************/
/************** Begin file vdbemem.c *****************************************/
/*
** 2004 May 26
**
** 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 file contains code use to manipulate "Mem" structure. A "Mem"
** stores a single value in the VDBE. Mem is an opaque structure visible
** only within the VDBE. Interface routines refer to a Mem using the
** name sqlite_value
*/
/* #include "sqliteInt.h" */
/* #include "vdbeInt.h" */
/* True if X is a power of two. 0 is considered a power of two here.
** In other words, return true if X has at most one bit set.
*/
#define ISPOWEROF2(X) (((X)&((X)-1))==0)
#ifdef SQLITE_DEBUG
/*
** Check invariants on a Mem object.
**
** This routine is intended for use inside of assert() statements, like
** this: assert( sqlite3VdbeCheckMemInvariants(pMem) );
*/
SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem *p){
/* If MEM_Dyn is set then Mem.xDel!=0.
** Mem.xDel might not be initialized if MEM_Dyn is clear.
*/
assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );
/* MEM_Dyn may only be set if Mem.szMalloc==0. In this way we
** ensure that if Mem.szMalloc>0 then it is safe to do
** Mem.z = Mem.zMalloc without having to check Mem.flags&MEM_Dyn.
** That saves a few cycles in inner loops. */
assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 );
/* Cannot have more than one of MEM_Int, MEM_Real, or MEM_IntReal */
assert( ISPOWEROF2(p->flags & (MEM_Int|MEM_Real|MEM_IntReal)) );
if( p->flags & MEM_Null ){
/* Cannot be both MEM_Null and some other type */
assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 );
/* If MEM_Null is set, then either the value is a pure NULL (the usual
** case) or it is a pointer set using sqlite3_bind_pointer() or
** sqlite3_result_pointer(). If a pointer, then MEM_Term must also be
** set.
*/
if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){
/* This is a pointer type. There may be a flag to indicate what to
** do with the pointer. */
VdbeBranchTaken(res!=0,2);
if( res ) goto jump_to_p2;
}
break;
}
/* Opcode: IfEmpty P1 P2 * * *
** Synopsis: if( empty(P1) ) goto P2
**
** Check to see if the b-tree table that cursor P1 references is empty
** and jump to P2 if it is.
*/
case OP_IfEmpty: { /* jump */
VdbeCursor *pC;
BtCursor *pCrsr;
int res;
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
assert( pOp->p2>=0 && pOp->p2<p->nOp );
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->eCurType==CURTYPE_BTREE );
pCrsr = pC->uc.pCursor;
assert( pCrsr );
rc = sqlite3BtreeIsEmpty(pCrsr, &res);
if( rc ) goto abort_due_to_error;
VdbeBranchTaken(res!=0,2);
if( res ) goto jump_to_p2;
break;
}
/* Opcode: Next P1 P2 P3 * P5
**
** Advance cursor P1 so that it points to the next key/data pair in its
** table or index. If there are no more key/value pairs then fall through
** to the following instruction. But if the cursor advance was successful,
** jump immediately to P2.
**
** The Next opcode is only valid following an SeekGT, SeekGE, or
** OP_Rewind opcode used to position the cursor. Next is not allowed
** to follow SeekLT, SeekLE, or OP_Last.
**
** The P1 cursor must be for a real table, not a pseudo-table. P1 must have
** been opened prior to this opcode or the program will segfault.
**
** The P3 value is a hint to the btree implementation. If P3==1, that
** means P1 is an SQL index and that this instruction could have been
** omitted if that index had been unique. P3 is usually 0. P3 is
** always either 0 or 1.
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
**
** See also: Prev
*/
/* Opcode: Prev P1 P2 P3 * P5
**
** Back up cursor P1 so that it points to the previous key/data pair in its
** table or index. If there is no previous key/value pairs then fall through
** to the following instruction. But if the cursor backup was successful,
** jump immediately to P2.
**
**
** The Prev opcode is only valid following an SeekLT, SeekLE, or
** OP_Last opcode used to position the cursor. Prev is not allowed
** to follow SeekGT, SeekGE, or OP_Rewind.
**
** The P1 cursor must be for a real table, not a pseudo-table. If P1 is
** not open then the behavior is undefined.
**
** The P3 value is a hint to the btree implementation. If P3==1, that
** means P1 is an SQL index and that this instruction could have been
** omitted if that index had been unique. P3 is usually 0. P3 is
** always either 0 or 1.
**
** If P5 is positive and the jump is taken, then event counter
** number P5-1 in the prepared statement is incremented.
*/
/* Opcode: SorterNext P1 P2 * * P5
**
** This opcode works just like OP_Next except that P1 must be a
** sorter object for which the OP_SorterSort opcode has been
** invoked. This opcode advances the cursor to the next sorted
** record, or jumps to P2 if there are no more sorted records.
*/
case OP_SorterNext: { /* jump */
VdbeCursor *pC;
pC = p->apCsr[pOp->p1];
assert( isSorter(pC) );
rc = sqlite3VdbeSorterNext(db, pC);
goto next_tail;
case OP_Prev: /* jump, ncycle */
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
assert( pOp->p5==0
|| pOp->p5==SQLITE_STMTSTATUS_FULLSCAN_STEP
|| pOp->p5==SQLITE_STMTSTATUS_AUTOINDEX);
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->deferredMoveto==0 );
assert( pC->eCurType==CURTYPE_BTREE );
assert( pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
|| pC->seekOp==OP_Last || pC->seekOp==OP_IfNoHope
|| pC->seekOp==OP_NullRow);
rc = sqlite3BtreePrevious(pC->uc.pCursor, pOp->p3);
goto next_tail;
case OP_Next: /* jump, ncycle */
assert( pOp->p1>=0 && pOp->p1<p->nCursor );
assert( pOp->p5==0
|| pOp->p5==SQLITE_STMTSTATUS_FULLSCAN_STEP
|| pOp->p5==SQLITE_STMTSTATUS_AUTOINDEX);
pC = p->apCsr[pOp->p1];
assert( pC!=0 );
assert( pC->deferredMoveto==0 );
assert( pC->eCurType==CURTYPE_BTREE );
assert( pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE
|| pC->seekOp==OP_Rewind || pC->seekOp==OP_Found
|| pC->seekOp==OP_NullRow|| pC->seekOp==OP_SeekRowid
/*
** The sqlite3_strglob() interface. Return 0 on a match (like strcmp()) and
** non-zero if there is no match.
*/
SQLITE_API int sqlite3_strglob(const char *zGlobPattern, const char *zString){
if( zString==0 ){
return zGlobPattern!=0;
}else if( zGlobPattern==0 ){
return 1;
}else {
return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');
}
}
/*
** The sqlite3_strlike() interface. Return 0 on a match and non-zero for
** a miss - like strcmp().
*/
SQLITE_API int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
if( zStr==0 ){
return zPattern!=0;
}else if( zPattern==0 ){
return 1;
}else{
return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);
}
}
/*
** Count the number of times that the LIKE operator (or GLOB which is
** just a variation of LIKE) gets called. This is used for testing
** only.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_like_count = 0;
#endif
/*
** Implementation of the like() SQL function. This function implements
** the built-in LIKE operator. The first argument to the function is the
** pattern and the second argument is the string. So, the SQL statements:
**
** A LIKE B
**
** is implemented as like(B,A).
**
** This same function (with a different compareInfo structure) computes
** the GLOB operator.
*/
static void likeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zA, *zB;
u32 escape;
int nPat;
sqlite3 *db = sqlite3_context_db_handle(context);
struct compareInfo *pInfo = sqlite3_user_data(context);
struct compareInfo backupInfo;
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
if( sqlite3_value_type(argv[0])==SQLITE_BLOB
|| sqlite3_value_type(argv[1])==SQLITE_BLOB
){
#ifdef SQLITE_TEST
sqlite3_like_count++;
#endif
sqlite3_result_int(context, 0);
return;
}
#endif
/* Limit the length of the LIKE or GLOB pattern to avoid problems
** of deep recursion and N*N behavior in patternCompare().
*/
nPat = sqlite3_value_bytes(argv[0]);
testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] );
testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 );
if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
return;
}
if( argc==3 ){
/* The escape character string must consist of a single UTF-8 character.
** Otherwise, return an error.
*/
const unsigned char *zEsc = sqlite3_value_text(argv[2]);
if( zEsc==0 ) return;
if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
sqlite3_result_error(context,
"ESCAPE expression must be a single character", -1);
return;
}
escape = sqlite3Utf8Read(&zEsc);
if( escape==pInfo->matchAll || escape==pInfo->matchOne ){
memcpy(&backupInfo, pInfo, sizeof(backupInfo));
pInfo = &backupInfo;
if( escape==pInfo->matchAll ) pInfo->matchAll = 0;
if( escape==pInfo->matchOne ) pInfo->matchOne = 0;
}
}else{
escape = pInfo->matchSet;
}
zB = sqlite3_value_text(argv[0]);
zA = sqlite3_value_text(argv[1]);
if( zA && zB ){
#ifdef SQLITE_TEST
sqlite3_like_count++;
#endif
sqlite3_result_int(context,
patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);
}
}
/*
** Implementation of the NULLIF(x,y) function. The result is the first
** argument if the arguments are different. The result is NULL if the
** arguments are equal to each other.
*/
static void nullifFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
UNUSED_PARAMETER(NotUsed);
if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
sqlite3_result_value(context, argv[0]);
}
}
/*
** Implementation of the sqlite_version() function. The result is the version
** of the SQLite library that is running.
*/
static void versionFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
/* IMP: R-48699-48617 This function is an SQL wrapper around the
** sqlite3_libversion() C-interface. */
sqlite3_result_text(context, sqlite3_libversion(), -1, SQLITE_STATIC);
}
/*
** Implementation of the sqlite_source_id() function. The result is a string
** that identifies the particular version of the source code used to build
** SQLite.
*/
static void sourceidFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
int (*value_bytes)(sqlite3_value*);
int (*value_bytes16)(sqlite3_value*);
double (*value_double)(sqlite3_value*);
int (*value_int)(sqlite3_value*);
sqlite_int64 (*value_int64)(sqlite3_value*);
int (*value_numeric_type)(sqlite3_value*);
const unsigned char * (*value_text)(sqlite3_value*);
const void * (*value_text16)(sqlite3_value*);
const void * (*value_text16be)(sqlite3_value*);
const void * (*value_text16le)(sqlite3_value*);
int (*value_type)(sqlite3_value*);
char *(*vmprintf)(const char*,va_list);
/* Added ??? */
int (*overload_function)(sqlite3*, const char *zFuncName, int nArg);
/* Added by 3.3.13 */
int (*prepare_v2)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);
int (*prepare16_v2)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);
int (*clear_bindings)(sqlite3_stmt*);
/* Added by 3.4.1 */
int (*create_module_v2)(sqlite3*,const char*,const sqlite3_module*,void*,
void (*xDestroy)(void *));
/* Added by 3.5.0 */
int (*bind_zeroblob)(sqlite3_stmt*,int,int);
int (*blob_bytes)(sqlite3_blob*);
int (*blob_close)(sqlite3_blob*);
int (*blob_open)(sqlite3*,const char*,const char*,const char*,sqlite3_int64,
int,sqlite3_blob**);
int (*blob_read)(sqlite3_blob*,void*,int,int);
int (*blob_write)(sqlite3_blob*,const void*,int,int);
int (*create_collation_v2)(sqlite3*,const char*,int,void*,
int(*)(void*,int,const void*,int,const void*),
void(*)(void*));
int (*file_control)(sqlite3*,const char*,int,void*);
sqlite3_int64 (*memory_highwater)(int);
sqlite3_int64 (*memory_used)(void);
sqlite3_mutex *(*mutex_alloc)(int);
void (*mutex_enter)(sqlite3_mutex*);
void (*mutex_free)(sqlite3_mutex*);
void (*mutex_leave)(sqlite3_mutex*);
int (*mutex_try)(sqlite3_mutex*);
int (*open_v2)(const char*,sqlite3**,int,const char*);
int (*release_memory)(int);
void (*result_error_nomem)(sqlite3_context*);
void (*result_error_toobig)(sqlite3_context*);
int (*sleep)(int);
void (*soft_heap_limit)(int);
sqlite3_vfs *(*vfs_find)(const char*);
int (*vfs_register)(sqlite3_vfs*,int);
int (*vfs_unregister)(sqlite3_vfs*);
int (*xthreadsafe)(void);
void (*result_zeroblob)(sqlite3_context*,int);
void (*result_error_code)(sqlite3_context*,int);
int (*test_control)(int, ...);
void (*randomness)(int,void*);
sqlite3 *(*context_db_handle)(sqlite3_context*);
int (*extended_result_codes)(sqlite3*,int);
int (*limit)(sqlite3*,int,int);
sqlite3_stmt *(*next_stmt)(sqlite3*,sqlite3_stmt*);
const char *(*sql)(sqlite3_stmt*);
int (*status)(int,int*,int*,int);
int (*backup_finish)(sqlite3_backup*);
sqlite3_backup *(*backup_init)(sqlite3*,const char*,sqlite3*,const char*);
int (*backup_pagecount)(sqlite3_backup*);
int (*backup_remaining)(sqlite3_backup*);
int (*backup_step)(sqlite3_backup*,int);
const char *(*compileoption_get)(int);
int (*compileoption_used)(const char*);
int (*create_function_v2)(sqlite3*,const char*,int,int,void*,
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
void (*xFinal)(sqlite3_context*),
void(*xDestroy)(void*));
int (*db_config)(sqlite3*,int,...);
sqlite3_mutex *(*db_mutex)(sqlite3*);
int (*db_status)(sqlite3*,int,int*,int*,int);
int (*extended_errcode)(sqlite3*);
void (*log)(int,const char*,...);
sqlite3_int64 (*soft_heap_limit64)(sqlite3_int64);
const char *(*sourceid)(void);
int (*stmt_status)(sqlite3_stmt*,int,int);
int (*strnicmp)(const char*,const char*,int);
int (*unlock_notify)(sqlite3*,void(*)(void**,int),void*);
int (*wal_autocheckpoint)(sqlite3*,int);
int (*wal_checkpoint)(sqlite3*,const char*);
void *(*wal_hook)(sqlite3*,int(*)(void*,sqlite3*,const char*,int),void*);
int (*blob_reopen)(sqlite3_blob*,sqlite3_int64);
int (*vtab_config)(sqlite3*,int op,...);
int (*vtab_on_conflict)(sqlite3*);
/* Version 3.7.16 and later */
int (*close_v2)(sqlite3*);
const char *(*db_filename)(sqlite3*,const char*);
int (*db_readonly)(sqlite3*,const char*);
int (*db_release_memory)(sqlite3*);
const char *(*errstr)(int);
int (*stmt_busy)(sqlite3_stmt*);
int (*stmt_readonly)(sqlite3_stmt*);
int (*stricmp)(const char*,const char*);
int (*uri_boolean)(const char*,const char*,int);
sqlite3_int64 (*uri_int64)(const char*,const char*,sqlite3_int64);
const char *(*uri_parameter)(const char*,const char*);
char *(*xvsnprintf)(int,char*,const char*,va_list);
int (*wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);
/* Version 3.8.7 and later */
int (*auto_extension)(void(*)(void));
int (*bind_blob64)(sqlite3_stmt*,int,const void*,sqlite3_uint64,
void(*)(void*));
int (*bind_text64)(sqlite3_stmt*,int,const char*,sqlite3_uint64,
void(*)(void*),unsigned char);
int (*cancel_auto_extension)(void(*)(void));
int (*load_extension)(sqlite3*,const char*,const char*,char**);
void *(*malloc64)(sqlite3_uint64);
sqlite3_uint64 (*msize)(void*);
void *(*realloc64)(void*,sqlite3_uint64);
void (*reset_auto_extension)(void);
void (*result_blob64)(sqlite3_context*,const void*,sqlite3_uint64,
void(*)(void*));
void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
void(*)(void*), unsigned char);
int (*strglob)(const char*,const char*);
/* Version 3.8.11 and later */
sqlite3_value *(*value_dup)(const sqlite3_value*);
void (*value_free)(sqlite3_value*);
int (*result_zeroblob64)(sqlite3_context*,sqlite3_uint64);
int (*bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);
/* Version 3.9.0 and later */
#define sqlite3_total_changes sqlite3_api->total_changes
#define sqlite3_trace sqlite3_api->trace
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_transfer_bindings sqlite3_api->transfer_bindings
#endif
#define sqlite3_update_hook sqlite3_api->update_hook
#define sqlite3_user_data sqlite3_api->user_data
#define sqlite3_value_blob sqlite3_api->value_blob
#define sqlite3_value_bytes sqlite3_api->value_bytes
#define sqlite3_value_bytes16 sqlite3_api->value_bytes16
#define sqlite3_value_double sqlite3_api->value_double
#define sqlite3_value_int sqlite3_api->value_int
#define sqlite3_value_int64 sqlite3_api->value_int64
#define sqlite3_value_numeric_type sqlite3_api->value_numeric_type
#define sqlite3_value_text sqlite3_api->value_text
#define sqlite3_value_text16 sqlite3_api->value_text16
#define sqlite3_value_text16be sqlite3_api->value_text16be
#define sqlite3_value_text16le sqlite3_api->value_text16le
#define sqlite3_value_type sqlite3_api->value_type
#define sqlite3_vmprintf sqlite3_api->vmprintf
#define sqlite3_vsnprintf sqlite3_api->xvsnprintf
#define sqlite3_overload_function sqlite3_api->overload_function
#define sqlite3_prepare_v2 sqlite3_api->prepare_v2
#define sqlite3_prepare16_v2 sqlite3_api->prepare16_v2
#define sqlite3_clear_bindings sqlite3_api->clear_bindings
#define sqlite3_bind_zeroblob sqlite3_api->bind_zeroblob
#define sqlite3_blob_bytes sqlite3_api->blob_bytes
#define sqlite3_blob_close sqlite3_api->blob_close
#define sqlite3_blob_open sqlite3_api->blob_open
#define sqlite3_blob_read sqlite3_api->blob_read
#define sqlite3_blob_write sqlite3_api->blob_write
#define sqlite3_create_collation_v2 sqlite3_api->create_collation_v2
#define sqlite3_file_control sqlite3_api->file_control
#define sqlite3_memory_highwater sqlite3_api->memory_highwater
#define sqlite3_memory_used sqlite3_api->memory_used
#define sqlite3_mutex_alloc sqlite3_api->mutex_alloc
#define sqlite3_mutex_enter sqlite3_api->mutex_enter
#define sqlite3_mutex_free sqlite3_api->mutex_free
#define sqlite3_mutex_leave sqlite3_api->mutex_leave
#define sqlite3_mutex_try sqlite3_api->mutex_try
#define sqlite3_open_v2 sqlite3_api->open_v2
#define sqlite3_release_memory sqlite3_api->release_memory
#define sqlite3_result_error_nomem sqlite3_api->result_error_nomem
#define sqlite3_result_error_toobig sqlite3_api->result_error_toobig
#define sqlite3_sleep sqlite3_api->sleep
#define sqlite3_soft_heap_limit sqlite3_api->soft_heap_limit
#define sqlite3_vfs_find sqlite3_api->vfs_find
#define sqlite3_vfs_register sqlite3_api->vfs_register
#define sqlite3_vfs_unregister sqlite3_api->vfs_unregister
#define sqlite3_threadsafe sqlite3_api->xthreadsafe
#define sqlite3_result_zeroblob sqlite3_api->result_zeroblob
#define sqlite3_result_error_code sqlite3_api->result_error_code
#define sqlite3_test_control sqlite3_api->test_control
#define sqlite3_randomness sqlite3_api->randomness
#define sqlite3_context_db_handle sqlite3_api->context_db_handle
#define sqlite3_extended_result_codes sqlite3_api->extended_result_codes
#define sqlite3_limit sqlite3_api->limit
#define sqlite3_next_stmt sqlite3_api->next_stmt
#define sqlite3_sql sqlite3_api->sql
#define sqlite3_status sqlite3_api->status
#define sqlite3_backup_finish sqlite3_api->backup_finish
#define sqlite3_backup_init sqlite3_api->backup_init
#define sqlite3_backup_pagecount sqlite3_api->backup_pagecount
#define sqlite3_backup_remaining sqlite3_api->backup_remaining
#define sqlite3_backup_step sqlite3_api->backup_step
#define sqlite3_compileoption_get sqlite3_api->compileoption_get
#define sqlite3_compileoption_used sqlite3_api->compileoption_used
#define sqlite3_create_function_v2 sqlite3_api->create_function_v2
#define sqlite3_db_config sqlite3_api->db_config
#define sqlite3_db_mutex sqlite3_api->db_mutex
#define sqlite3_db_status sqlite3_api->db_status
#define sqlite3_extended_errcode sqlite3_api->extended_errcode
#define sqlite3_log sqlite3_api->log
#define sqlite3_soft_heap_limit64 sqlite3_api->soft_heap_limit64
#define sqlite3_sourceid sqlite3_api->sourceid
#define sqlite3_stmt_status sqlite3_api->stmt_status
#define sqlite3_strnicmp sqlite3_api->strnicmp
#define sqlite3_unlock_notify sqlite3_api->unlock_notify
#define sqlite3_wal_autocheckpoint sqlite3_api->wal_autocheckpoint
#define sqlite3_wal_checkpoint sqlite3_api->wal_checkpoint
#define sqlite3_wal_hook sqlite3_api->wal_hook
#define sqlite3_blob_reopen sqlite3_api->blob_reopen
#define sqlite3_vtab_config sqlite3_api->vtab_config
#define sqlite3_vtab_on_conflict sqlite3_api->vtab_on_conflict
/* Version 3.7.16 and later */
#define sqlite3_close_v2 sqlite3_api->close_v2
#define sqlite3_db_filename sqlite3_api->db_filename
#define sqlite3_db_readonly sqlite3_api->db_readonly
#define sqlite3_db_release_memory sqlite3_api->db_release_memory
#define sqlite3_errstr sqlite3_api->errstr
#define sqlite3_stmt_busy sqlite3_api->stmt_busy
#define sqlite3_stmt_readonly sqlite3_api->stmt_readonly
#define sqlite3_stricmp sqlite3_api->stricmp
#define sqlite3_uri_boolean sqlite3_api->uri_boolean
#define sqlite3_uri_int64 sqlite3_api->uri_int64
#define sqlite3_uri_parameter sqlite3_api->uri_parameter
#define sqlite3_uri_vsnprintf sqlite3_api->xvsnprintf
#define sqlite3_wal_checkpoint_v2 sqlite3_api->wal_checkpoint_v2
/* Version 3.8.7 and later */
#define sqlite3_auto_extension sqlite3_api->auto_extension
#define sqlite3_bind_blob64 sqlite3_api->bind_blob64
#define sqlite3_bind_text64 sqlite3_api->bind_text64
#define sqlite3_cancel_auto_extension sqlite3_api->cancel_auto_extension
#define sqlite3_load_extension sqlite3_api->load_extension
#define sqlite3_malloc64 sqlite3_api->malloc64
#define sqlite3_msize sqlite3_api->msize
#define sqlite3_realloc64 sqlite3_api->realloc64
#define sqlite3_reset_auto_extension sqlite3_api->reset_auto_extension
#define sqlite3_result_blob64 sqlite3_api->result_blob64
#define sqlite3_result_text64 sqlite3_api->result_text64
#define sqlite3_strglob sqlite3_api->strglob
/* Version 3.8.11 and later */
#define sqlite3_value_dup sqlite3_api->value_dup
#define sqlite3_value_free sqlite3_api->value_free
#define sqlite3_result_zeroblob64 sqlite3_api->result_zeroblob64
#define sqlite3_bind_zeroblob64 sqlite3_api->bind_zeroblob64
/* Version 3.9.0 and later */
#define sqlite3_value_subtype sqlite3_api->value_subtype
#define sqlite3_result_subtype sqlite3_api->result_subtype
/* Version 3.10.0 and later */
#define sqlite3_status64 sqlite3_api->status64
#define sqlite3_strlike sqlite3_api->strlike
#define sqlite3_db_cacheflush sqlite3_api->db_cacheflush
/* Version 3.12.0 and later */
#define sqlite3_system_errno sqlite3_api->system_errno
sqlite3_create_module_v2,
/*
** Added for 3.5.0
*/
sqlite3_bind_zeroblob,
sqlite3_blob_bytes,
sqlite3_blob_close,
sqlite3_blob_open,
sqlite3_blob_read,
sqlite3_blob_write,
sqlite3_create_collation_v2,
sqlite3_file_control,
sqlite3_memory_highwater,
sqlite3_memory_used,
#ifdef SQLITE_MUTEX_OMIT
0,
0,
0,
0,
0,
#else
sqlite3_mutex_alloc,
sqlite3_mutex_enter,
sqlite3_mutex_free,
sqlite3_mutex_leave,
sqlite3_mutex_try,
#endif
sqlite3_open_v2,
sqlite3_release_memory,
sqlite3_result_error_nomem,
sqlite3_result_error_toobig,
sqlite3_sleep,
sqlite3_soft_heap_limit,
sqlite3_vfs_find,
sqlite3_vfs_register,
sqlite3_vfs_unregister,
/*
** Added for 3.5.8
*/
sqlite3_threadsafe,
sqlite3_result_zeroblob,
sqlite3_result_error_code,
sqlite3_test_control,
sqlite3_randomness,
sqlite3_context_db_handle,
/*
** Added for 3.6.0
*/
sqlite3_extended_result_codes,
sqlite3_limit,
sqlite3_next_stmt,
sqlite3_sql,
sqlite3_status,
/*
** Added for 3.7.4
*/
sqlite3_backup_finish,
sqlite3_backup_init,
sqlite3_backup_pagecount,
sqlite3_backup_remaining,
sqlite3_backup_step,
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
sqlite3_compileoption_get,
sqlite3_compileoption_used,
#else
0,
0,
#endif
sqlite3_create_function_v2,
sqlite3_db_config,
sqlite3_db_mutex,
sqlite3_db_status,
sqlite3_extended_errcode,
sqlite3_log,
sqlite3_soft_heap_limit64,
sqlite3_sourceid,
sqlite3_stmt_status,
sqlite3_strnicmp,
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
sqlite3_unlock_notify,
#else
0,
#endif
#ifndef SQLITE_OMIT_WAL
sqlite3_wal_autocheckpoint,
sqlite3_wal_checkpoint,
sqlite3_wal_hook,
#else
0,
0,
0,
#endif
sqlite3_blob_reopen,
sqlite3_vtab_config,
sqlite3_vtab_on_conflict,
sqlite3_close_v2,
sqlite3_db_filename,
sqlite3_db_readonly,
sqlite3_db_release_memory,
sqlite3_errstr,
sqlite3_stmt_busy,
sqlite3_stmt_readonly,
sqlite3_stricmp,
sqlite3_uri_boolean,
sqlite3_uri_int64,
sqlite3_uri_parameter,
sqlite3_vsnprintf,
sqlite3_wal_checkpoint_v2,
/* Version 3.8.7 and later */
sqlite3_auto_extension,
sqlite3_bind_blob64,
sqlite3_bind_text64,
sqlite3_cancel_auto_extension,
sqlite3_load_extension,
sqlite3_malloc64,
sqlite3_msize,
sqlite3_realloc64,
sqlite3_reset_auto_extension,
sqlite3_result_blob64,
sqlite3_result_text64,
sqlite3_strglob,
db->pSavepoint = pTmp->pNext;
sqlite3DbFree(db, pTmp);
}
db->nSavepoint = 0;
db->nStatement = 0;
db->isTransactionSavepoint = 0;
}
/*
** Invoke the destructor function associated with FuncDef p, if any. Except,
** if this is not the last copy of the function, do not invoke it. Multiple
** copies of a single function are created when create_function() is called
** with SQLITE_ANY as the encoding.
*/
static void functionDestroy(sqlite3 *db, FuncDef *p){
FuncDestructor *pDestructor;
assert( (p->funcFlags & SQLITE_FUNC_BUILTIN)==0 );
pDestructor = p->u.pDestructor;
if( pDestructor ){
pDestructor->nRef--;
if( pDestructor->nRef==0 ){
pDestructor->xDestroy(pDestructor->pUserData);
sqlite3DbFree(db, pDestructor);
}
}
}
/*
** Disconnect all sqlite3_vtab objects that belong to database connection
** db. This is called when db is being closed.
*/
static void disconnectAllVtab(sqlite3 *db){
#ifndef SQLITE_OMIT_VIRTUALTABLE
int i;
HashElem *p;
sqlite3BtreeEnterAll(db);
for(i=0; i<db->nDb; i++){
Schema *pSchema = db->aDb[i].pSchema;
if( pSchema ){
for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
Table *pTab = (Table *)sqliteHashData(p);
if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
}
}
}
for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
Module *pMod = (Module *)sqliteHashData(p);
if( pMod->pEpoTab ){
sqlite3VtabDisconnect(db, pMod->pEpoTab);
}
}
sqlite3VtabUnlockList(db);
sqlite3BtreeLeaveAll(db);
#else
UNUSED_PARAMETER(db);
#endif
}
/*
** Return TRUE if database connection db has unfinalized prepared
** statements or unfinished sqlite3_backup objects.
*/
static int connectionIsBusy(sqlite3 *db){
int j;
assert( sqlite3_mutex_held(db->mutex) );
if( db->pVdbe ) return 1;
for(j=0; j<db->nDb; j++){
Btree *pBt = db->aDb[j].pBt;
if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
}
return 0;
}
/*
** Close an existing SQLite database
*/
static int sqlite3Close(sqlite3 *db, int forceZombie){
if( !db ){
/* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
return SQLITE_OK;
}
if( !sqlite3SafetyCheckSickOrOk(db) ){
return SQLITE_MISUSE_BKPT;
}
sqlite3_mutex_enter(db->mutex);
if( db->mTrace & SQLITE_TRACE_CLOSE ){
db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
}
/* Force xDisconnect calls on all virtual tables */
disconnectAllVtab(db);
/* If a transaction is open, the disconnectAllVtab() call above
** will not have called the xDisconnect() method on any virtual
** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
** call will do so. We need to do this before the check for active
** SQL statements below, as the v-table implementation may be storing
** some prepared statements internally.
*/
sqlite3VtabRollback(db);
/* Legacy behavior (sqlite3_close() behavior) is to return
** SQLITE_BUSY if the connection can not be closed immediately.
*/
if( !forceZombie && connectionIsBusy(db) ){
sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
"statements or unfinished backups");
sqlite3_mutex_leave(db->mutex);
return SQLITE_BUSY;
}
#ifdef SQLITE_ENABLE_SQLLOG
if( sqlite3GlobalConfig.xSqllog ){
/* Closing the handle. Fourth parameter is passed the value 2. */
sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
}
#endif
while( db->pDbData ){
DbClientData *p = db->pDbData;
db->pDbData = p->pNext;
assert( p->pData!=0 );
if( p->xDestructor ) p->xDestructor(p->pData);
sqlite3_free(p);
}
/* Convert the connection into a zombie and then close it.
*/
db->eOpenState = SQLITE_STATE_ZOMBIE;
sqlite3LeaveMutexAndCloseZombie(db);
return SQLITE_OK;
}
/*
** Return the transaction state for a single databse, or the maximum
** transaction state over all attached databases if zSchema is null.
*/
SQLITE_API int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
int iDb, nDb;
int iTxn = -1;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) ){
(void)SQLITE_MISUSE_BKPT;
return -1;
}
#endif
sqlite3_mutex_enter(db->mutex);
if( zSchema ){
nDb = iDb = sqlite3FindDbName(db, zSchema);
if( iDb<0 ) nDb--;
}else{
iDb = 0;
nDb = db->nDb-1;
}
for(; iDb<=nDb; iDb++){
Btree *pBt = db->aDb[iDb].pBt;
int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
if( x>iTxn ) iTxn = x;
}
sqlite3_mutex_leave(db->mutex);
return iTxn;
}
/*
** Two variations on the public interface for closing a database
** connection. The sqlite3_close() version returns SQLITE_BUSY and
** leaves the connection open if there are unfinalized prepared
** statements or unfinished sqlite3_backups. The sqlite3_close_v2()
** version forces the connection to become a zombie if there are
** unclosed resources, and arranges for deallocation when the last
** prepare statement or sqlite3_backup closes.
*/
SQLITE_API int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
SQLITE_API int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
/*
** Close the mutex on database connection db.
**
** Furthermore, if database connection db is a zombie (meaning that there
** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
** every sqlite3_stmt has now been finalized and every sqlite3_backup has
** finished, then free all resources.
*/
SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
HashElem *i; /* Hash table iterator */
int j;
/* If there are outstanding sqlite3_stmt or sqlite3_backup objects
** or if the connection has not yet been closed by sqlite3_close_v2(),
** then just leave the mutex and return.
*/
if( db->eOpenState!=SQLITE_STATE_ZOMBIE || connectionIsBusy(db) ){
sqlite3_mutex_leave(db->mutex);
return;
}
/* If we reach this point, it means that the database connection has
** closed all sqlite3_stmt and sqlite3_backup objects and has been
** passed to sqlite3_close (meaning that it is a zombie). Therefore,
** go ahead and free all resources.
*/
/* If a transaction is open, roll it back. This also ensures that if
** any database schemas have been modified by an uncommitted transaction
** they are reset. And that the required b-tree mutex is held to make
** the pager rollback and schema reset an atomic operation. */
sqlite3RollbackAll(db, SQLITE_OK);
/* Free any outstanding Savepoint structures. */
sqlite3CloseSavepoints(db);
/* Close all database connections */
for(j=0; j<db->nDb; j++){
struct Db *pDb = &db->aDb[j];
if( pDb->pBt ){
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
if( j!=1 ){
pDb->pSchema = 0;
}
}
}
/* Clear the TEMP schema separately and last */
if( db->aDb[1].pSchema ){
sqlite3SchemaClear(db->aDb[1].pSchema);
assert( db->aDb[1].pSchema->trigHash.count==0 );
}
sqlite3VtabUnlockList(db);
/* Free up the array of auxiliary databases */
sqlite3CollapseDatabaseArray(db);
assert( db->nDb<=2 );
assert( db->aDb==db->aDbStatic );
/* Tell the code in notify.c that the connection no longer holds any
** locks and does not require any further unlock-notify callbacks.
*/
sqlite3ConnectionClosed(db);
for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
FuncDef *pNext, *p;
p = sqliteHashData(i);
do{
functionDestroy(db, p);
pNext = p->pNext;
sqlite3DbFree(db, p);
p = pNext;
}while( p );
}
sqlite3HashClear(&db->aFunc);
for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
CollSeq *pColl = (CollSeq *)sqliteHashData(i);
/* Invoke any destructors registered for collation sequence user data. */
for(j=0; j<3; j++){
if( pColl[j].xDel ){
pColl[j].xDel(pColl[j].pUser);
}
}
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