DBD-SQLite-Amalgamation
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sqlite-amalgamation.c view on Meta::CPAN
** New error codes may be added in future versions of SQLite.
**
** See also: [SQLITE_IOERR_READ | extended result codes]
*/
#define SQLITE_OK 0 /* Successful result */
/* beginning-of-error-codes */
#define SQLITE_ERROR 1 /* SQL error or missing database */
#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* The database file is locked */
#define SQLITE_LOCKED 6 /* A table in the database is locked */
#define SQLITE_NOMEM 7 /* A malloc() failed */
#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */
#define SQLITE_FULL 13 /* Insertion failed because database is full */
#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */
#define SQLITE_EMPTY 16 /* Database is empty */
sqlite-amalgamation.c view on Meta::CPAN
** UTF-16 string in native byte order.
*/
SQLITE_API int sqlite3_complete(const char *sql);
SQLITE_API int sqlite3_complete16(const void *sql);
/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400>
**
** This routine sets a callback function that might be invoked whenever
** an attempt is made to open a database table that another thread
** or process has locked.
**
** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock. If the busy callback
** is not NULL, then the callback will be invoked with two arguments.
**
** The first argument to the handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler(). The second argument to
** the handler callback is the number of times that the busy handler has
** been invoked for this locking event. If the
** busy callback returns 0, then no additional attempts are made to
sqlite-amalgamation.c view on Meta::CPAN
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that it will be invoked
** when there is lock contention. If SQLite determines that invoking the busy
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock. The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first. If both processes
** invoke the busy handlers, neither will make any progress. Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** The default busy callback is NULL.
**
** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache. SQLite will
sqlite-amalgamation.c view on Meta::CPAN
**
** {A12319} A busy handler must not close the database connection
** or [prepared statement] that invoked the busy handler.
*/
SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
/*
** CAPI3REF: Set A Busy Timeout {H12340} <S40410>
**
** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
** for a specified amount of time when a table is locked. The handler
** will sleep multiple times until at least "ms" milliseconds of sleeping
** have accumulated. {H12343} After "ms" milliseconds of sleeping,
** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** There can only be a single busy handler for a particular
** [database connection] any any given moment. If another busy handler
sqlite-amalgamation.c view on Meta::CPAN
p->id = iType;
InitializeCriticalSection(&p->mutex);
}
break;
}
default: {
static sqlite3_mutex staticMutexes[6];
static int isInit = 0;
while( !isInit ){
static long lock = 0;
if( InterlockedIncrement(&lock)==1 ){
int i;
for(i=0; i<sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++){
InitializeCriticalSection(&staticMutexes[i].mutex);
}
isInit = 1;
}else{
Sleep(1);
}
}
assert( iType-2 >= 0 );
sqlite-amalgamation.c view on Meta::CPAN
** inode.
**
** The sqlite3_file structure for POSIX is no longer just an integer file
** descriptor. It is now a structure that holds the integer file
** descriptor and a pointer to a structure that describes the internal
** locks on the corresponding inode. There is one locking structure
** per inode, so if the same inode is opened twice, both unixFile structures
** point to the same locking structure. The locking structure keeps
** a reference count (so we will know when to delete it) and a "cnt"
** field that tells us its internal lock status. cnt==0 means the
** file is unlocked. cnt==-1 means the file has an exclusive lock.
** cnt>0 means there are cnt shared locks on the file.
**
** Any attempt to lock or unlock a file first checks the locking
** structure. The fcntl() system call is only invoked to set a
** POSIX lock if the internal lock structure transitions between
** a locked and an unlocked state.
**
** 2004-Jan-11:
** More recent discoveries about POSIX advisory locks. (The more
** I discover, the more I realize the a POSIX advisory locks are
** an abomination.)
**
** If you close a file descriptor that points to a file that has locks,
** all locks on that file that are owned by the current process are
** released. To work around this problem, each unixFile structure contains
** a pointer to an openCnt structure. There is one openCnt structure
sqlite-amalgamation.c view on Meta::CPAN
int threadsOverrideEachOthersLocks = SQLITE_THREAD_OVERRIDE_LOCK;
#else
static int threadsOverrideEachOthersLocks = SQLITE_THREAD_OVERRIDE_LOCK;
#endif
/*
** This structure holds information passed into individual test
** threads by the testThreadLockingBehavior() routine.
*/
struct threadTestData {
int fd; /* File to be locked */
struct flock lock; /* The locking operation */
int result; /* Result of the locking operation */
};
#ifdef SQLITE_LOCK_TRACE
/*
** Print out information about all locking operations.
**
** This routine is used for troubleshooting locks on multithreaded
** platforms. Enable by compiling with the -DSQLITE_LOCK_TRACE
sqlite-amalgamation.c view on Meta::CPAN
/*
** If we are currently in a different thread than the thread that the
** unixFile argument belongs to, then transfer ownership of the unixFile
** over to the current thread.
**
** A unixFile is only owned by a thread on systems where one thread is
** unable to override locks created by a different thread. RedHat9 is
** an example of such a system.
**
** Ownership transfer is only allowed if the unixFile is currently unlocked.
** If the unixFile is locked and an ownership is wrong, then return
** SQLITE_MISUSE. SQLITE_OK is returned if everything works.
*/
#if SQLITE_THREADSAFE
static int transferOwnership(unixFile *pFile){
int rc;
pthread_t hSelf;
if( threadsOverrideEachOthersLocks ){
/* Ownership transfers not needed on this system */
return SQLITE_OK;
}
sqlite-amalgamation.c view on Meta::CPAN
*/
if( *pSize==1 ) *pSize = 0;
return SQLITE_OK;
}
/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero. If the file is unlocked or holds only SHARED locks, then
** return zero.
*/
static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
int r = 0;
unixFile *pFile = (unixFile*)id;
SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
assert( pFile );
enterMutex(); /* Because pFile->pLock is shared across threads */
sqlite-amalgamation.c view on Meta::CPAN
** confusion with SQLite lock names). The algorithms are complicated
** slightly in order to be compatible with windows systems simultaneously
** accessing the same database file, in case that is ever required.
**
** Symbols defined in os.h indentify the 'pending byte' and the 'reserved
** byte', each single bytes at well known offsets, and the 'shared byte
** range', a range of 510 bytes at a well known offset.
**
** To obtain a SHARED lock, a read-lock is obtained on the 'pending
** byte'. If this is successful, a random byte from the 'shared byte
** range' is read-locked and the lock on the 'pending byte' released.
**
** A process may only obtain a RESERVED lock after it has a SHARED lock.
** A RESERVED lock is implemented by grabbing a write-lock on the
** 'reserved byte'.
**
** A process may only obtain a PENDING lock after it has obtained a
** SHARED lock. A PENDING lock is implemented by obtaining a write-lock
** on the 'pending byte'. This ensures that no new SHARED locks can be
** obtained, but existing SHARED locks are allowed to persist. A process
** does not have to obtain a RESERVED lock on the way to a PENDING lock.
sqlite-amalgamation.c view on Meta::CPAN
typedef struct afpLockingContext afpLockingContext;
struct afpLockingContext {
unsigned long long sharedLockByte;
const char *filePath;
};
struct ByteRangeLockPB2
{
unsigned long long offset; /* offset to first byte to lock */
unsigned long long length; /* nbr of bytes to lock */
unsigned long long retRangeStart; /* nbr of 1st byte locked if successful */
unsigned char unLockFlag; /* 1 = unlock, 0 = lock */
unsigned char startEndFlag; /* 1=rel to end of fork, 0=rel to start */
int fd; /* file desc to assoc this lock with */
};
#define afpfsByteRangeLock2FSCTL _IOWR('z', 23, struct ByteRangeLockPB2)
/*
** Return 0 on success, 1 on failure. To match the behavior of the
** normal posix file locking (used in unixLock for example), we should
sqlite-amalgamation.c view on Meta::CPAN
strerror(errno));
return 1; /* error */
} else {
return 0;
}
}
/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero. If the file is unlocked or holds only SHARED locks, then
** return zero.
*/
static int afpCheckReservedLock(sqlite3_file *id, int *pResOut){
int r = 0;
unixFile *pFile = (unixFile*)id;
assert( pFile );
afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;
/* Check if a thread in this process holds such a lock */
sqlite-amalgamation.c view on Meta::CPAN
pPager->errCode==SQLITE_OK ||
(pPager->errCode & 0xff)==SQLITE_IOERR
);
if(
rc2==SQLITE_FULL ||
rc2==SQLITE_IOERR ||
rc2==SQLITE_CORRUPT
){
pPager->errCode = rc;
if( pPager->state==PAGER_UNLOCK && pPager->nRef==0 ){
/* If the pager is already unlocked, call pager_unlock() now to
** clear the error state and ensure that the pager-cache is
** completely empty.
*/
pager_unlock(pPager);
}
}
return rc;
}
/*
sqlite-amalgamation.c view on Meta::CPAN
** delete the file out from under us.
*/
if( pPager->journalOpen ){
sqlite3OsClose(pPager->jfd);
pPager->journalOpen = 0;
sqlite3BitvecDestroy(pPager->pInJournal);
pPager->pInJournal = 0;
}
/* If Pager.errCode is set, the contents of the pager cache cannot be
** trusted. Now that the pager file is unlocked, the contents of the
** cache can be discarded and the error code safely cleared.
*/
if( pPager->errCode ){
if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
pager_reset(pPager);
if( pPager->stmtOpen ){
sqlite3OsClose(pPager->stfd);
sqlite3BitvecDestroy(pPager->pInStmt);
pPager->pInStmt = 0;
}
sqlite-amalgamation.c view on Meta::CPAN
** Ticket #1171: The statement journal might contain page content that is
** different from the page content at the start of the transaction.
** This occurs when a page is changed prior to the start of a statement
** then changed again within the statement. When rolling back such a
** statement we must not write to the original database unless we know
** for certain that original page contents are synced into the main rollback
** journal. Otherwise, a power loss might leave modified data in the
** database file without an entry in the rollback journal that can
** restore the database to its original form. Two conditions must be
** met before writing to the database files. (1) the database must be
** locked. (2) we know that the original page content is fully synced
** in the main journal either because the page is not in cache or else
** the page is marked as needSync==0.
**
** 2008-04-14: When attempting to vacuum a corrupt database file, it
** is possible to fail a statement on a database that does not yet exist.
** Do not attempt to write if database file has never been opened.
*/
pPg = pager_lookup(pPager, pgno);
PAGERTRACE4("PLAYBACK %d page %d hash(%08x)\n",
PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, aData));
sqlite-amalgamation.c view on Meta::CPAN
vfsFlags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;
rc = sqlite3OsOpen(pPager->pVfs, 0, pFile, vfsFlags, 0);
assert( rc!=SQLITE_OK || pFile->pMethods );
return rc;
}
/*
** Create a new page cache and put a pointer to the page cache in *ppPager.
** The file to be cached need not exist. The file is not locked until
** the first call to sqlite3PagerGet() and is only held open until the
** last page is released using sqlite3PagerUnref().
**
** If zFilename is NULL then a randomly-named temporary file is created
** and used as the file to be cached. The file will be deleted
** automatically when it is closed.
**
** If zFilename is ":memory:" then all information is held in cache.
** It is never written to disk. This can be used to implement an
** in-memory database.
sqlite-amalgamation.c view on Meta::CPAN
** the lock.
*/
static int pager_wait_on_lock(Pager *pPager, int locktype){
int rc;
/* The OS lock values must be the same as the Pager lock values */
assert( PAGER_SHARED==SHARED_LOCK );
assert( PAGER_RESERVED==RESERVED_LOCK );
assert( PAGER_EXCLUSIVE==EXCLUSIVE_LOCK );
/* If the file is currently unlocked then the size must be unknown */
assert( pPager->state>=PAGER_SHARED || pPager->dbSize<0 || MEMDB );
if( pPager->state>=locktype ){
rc = SQLITE_OK;
}else{
if( pPager->pBusyHandler ) pPager->pBusyHandler->nBusy = 0;
do {
rc = sqlite3OsLock(pPager->fd, locktype);
}while( rc==SQLITE_BUSY && sqlite3InvokeBusyHandler(pPager->pBusyHandler) );
if( rc==SQLITE_OK ){
sqlite-amalgamation.c view on Meta::CPAN
** journal file exists and is not empty this routine assumes it
** is hot. The pager_playback() routine will discover that the
** journal file is not really hot and will no-op.
*/
static int hasHotJournal(Pager *pPager, int *pExists){
sqlite3_vfs *pVfs = pPager->pVfs;
int rc = SQLITE_OK;
*pExists = 0;
if( pPager->useJournal && pPager->fd->pMethods ){
int exists;
int locked;
rc = sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &exists);
if( rc==SQLITE_OK && exists ){
rc = sqlite3OsCheckReservedLock(pPager->fd, &locked);
}
if( rc==SQLITE_OK && exists && !locked ){
int nPage;
rc = sqlite3PagerPagecount(pPager, &nPage);
if( rc==SQLITE_OK ){
if( nPage==0 ){
sqlite3OsDelete(pVfs, pPager->zJournal, 0);
}else{
*pExists = 1;
}
}
}
sqlite-amalgamation.c view on Meta::CPAN
** 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 do 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 */
int wantToLock; /* Number of nested calls to sqlite3BtreeEnter() */
Btree *pNext; /* List of other sharable Btrees from the same db */
Btree *pPrev; /* Back pointer of the same list */
};
/*
** 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,
sqlite-amalgamation.c view on Meta::CPAN
/*
** Enter a mutex on the given BTree object.
**
** If the object is not sharable, then no mutex is ever required
** and this routine is a no-op. The underlying mutex is non-recursive.
** But we keep a reference count in Btree.wantToLock so the behavior
** of this interface is recursive.
**
** To avoid deadlocks, multiple Btrees are locked in the same order
** by all database connections. The p->pNext is a list of other
** Btrees belonging to the same database connection as the p Btree
** which need to be locked after p. If we cannot get a lock on
** p, then first unlock all of the others on p->pNext, then wait
** for the lock to become available on p, then relock all of the
** subsequent Btrees that desire a lock.
*/
SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){
Btree *pLater;
/* Some basic sanity checking on the Btree. The list of Btrees
** connected by pNext and pPrev should be in sorted order by
** Btree.pBt value. All elements of the list should belong to
** the same connection. Only shared Btrees are on the list. */
assert( p->pNext==0 || p->pNext->pBt>p->pBt );
assert( p->pPrev==0 || p->pPrev->pBt<p->pBt );
assert( p->pNext==0 || p->pNext->db==p->db );
assert( p->pPrev==0 || p->pPrev->db==p->db );
assert( p->sharable || (p->pNext==0 && p->pPrev==0) );
/* Check for locking consistency */
assert( !p->locked || p->wantToLock>0 );
assert( p->sharable || p->wantToLock==0 );
/* We should already hold a lock on the database connection */
assert( sqlite3_mutex_held(p->db->mutex) );
if( !p->sharable ) return;
p->wantToLock++;
if( p->locked ) return;
#ifndef SQLITE_MUTEX_NOOP
/* In most cases, we should be able to acquire the lock we
** want without having to go throught the ascending lock
** procedure that follows. Just be sure not to block.
*/
if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
p->locked = 1;
return;
}
/* To avoid deadlock, first release all locks with a larger
** BtShared address. Then acquire our lock. Then reacquire
** the other BtShared locks that we used to hold in ascending
** order.
*/
for(pLater=p->pNext; pLater; pLater=pLater->pNext){
assert( pLater->sharable );
assert( pLater->pNext==0 || pLater->pNext->pBt>pLater->pBt );
assert( !pLater->locked || pLater->wantToLock>0 );
if( pLater->locked ){
sqlite3_mutex_leave(pLater->pBt->mutex);
pLater->locked = 0;
}
}
sqlite3_mutex_enter(p->pBt->mutex);
p->locked = 1;
for(pLater=p->pNext; pLater; pLater=pLater->pNext){
if( pLater->wantToLock ){
sqlite3_mutex_enter(pLater->pBt->mutex);
pLater->locked = 1;
}
}
#endif /* SQLITE_MUTEX_NOOP */
}
/*
** Exit the recursive mutex on a Btree.
*/
SQLITE_PRIVATE void sqlite3BtreeLeave(Btree *p){
if( p->sharable ){
assert( p->wantToLock>0 );
p->wantToLock--;
if( p->wantToLock==0 ){
assert( p->locked );
sqlite3_mutex_leave(p->pBt->mutex);
p->locked = 0;
}
}
}
#ifndef NDEBUG
/*
** Return true if the BtShared mutex is held on the btree.
**
** This routine makes no determination one why or another if the
** database connection mutex is held.
**
** This routine is used only from within assert() statements.
*/
SQLITE_PRIVATE int sqlite3BtreeHoldsMutex(Btree *p){
return (p->sharable==0 ||
(p->locked && p->wantToLock && sqlite3_mutex_held(p->pBt->mutex)));
}
#endif
#ifndef SQLITE_OMIT_INCRBLOB
/*
** Enter and leave a mutex on a Btree given a cursor owned by that
** Btree. These entry points are used by incremental I/O and can be
** omitted if that module is not used.
*/
sqlite-amalgamation.c view on Meta::CPAN
** at the same instant.
*/
SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){
int i;
Btree *p, *pLater;
assert( sqlite3_mutex_held(db->mutex) );
for(i=0; i<db->nDb; i++){
p = db->aDb[i].pBt;
if( p && p->sharable ){
p->wantToLock++;
if( !p->locked ){
assert( p->wantToLock==1 );
while( p->pPrev ) p = p->pPrev;
while( p->locked && p->pNext ) p = p->pNext;
for(pLater = p->pNext; pLater; pLater=pLater->pNext){
if( pLater->locked ){
sqlite3_mutex_leave(pLater->pBt->mutex);
pLater->locked = 0;
}
}
while( p ){
sqlite3_mutex_enter(p->pBt->mutex);
p->locked++;
p = p->pNext;
}
}
}
}
}
SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){
int i;
Btree *p;
assert( sqlite3_mutex_held(db->mutex) );
for(i=0; i<db->nDb; i++){
p = db->aDb[i].pBt;
if( p && p->sharable ){
assert( p->wantToLock>0 );
p->wantToLock--;
if( p->wantToLock==0 ){
assert( p->locked );
sqlite3_mutex_leave(p->pBt->mutex);
p->locked = 0;
}
}
}
}
#ifndef NDEBUG
/*
** Return true if the current thread holds the database connection
** mutex and all required BtShared mutexes.
**
sqlite-amalgamation.c view on Meta::CPAN
** Enter the mutex of every btree in the array. This routine is
** called at the beginning of sqlite3VdbeExec(). The mutexes are
** exited at the end of the same function.
*/
SQLITE_PRIVATE void sqlite3BtreeMutexArrayEnter(BtreeMutexArray *pArray){
int i;
for(i=0; i<pArray->nMutex; i++){
Btree *p = pArray->aBtree[i];
/* Some basic sanity checking */
assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
assert( !p->locked || p->wantToLock>0 );
/* We should already hold a lock on the database connection */
assert( sqlite3_mutex_held(p->db->mutex) );
p->wantToLock++;
if( !p->locked && p->sharable ){
sqlite3_mutex_enter(p->pBt->mutex);
p->locked = 1;
}
}
}
/*
** Leave the mutex of every btree in the group.
*/
SQLITE_PRIVATE void sqlite3BtreeMutexArrayLeave(BtreeMutexArray *pArray){
int i;
for(i=0; i<pArray->nMutex; i++){
Btree *p = pArray->aBtree[i];
/* Some basic sanity checking */
assert( i==0 || pArray->aBtree[i-1]->pBt<p->pBt );
assert( p->locked || !p->sharable );
assert( p->wantToLock>0 );
/* We should already hold a lock on the database connection */
assert( sqlite3_mutex_held(p->db->mutex) );
p->wantToLock--;
if( p->wantToLock==0 && p->locked ){
sqlite3_mutex_leave(p->pBt->mutex);
p->locked = 0;
}
}
}
#endif /* SQLITE_THREADSAFE && !SQLITE_OMIT_SHARED_CACHE */
/************** End of btmutex.c *********************************************/
/************** Begin file btree.c *******************************************/
/*
sqlite-amalgamation.c view on Meta::CPAN
** The call to sqlite3BtreeRollback() drops any table-locks held by
** this handle.
*/
sqlite3BtreeRollback(p);
sqlite3BtreeLeave(p);
/* If there are still other outstanding references to the shared-btree
** structure, return now. The remainder of this procedure cleans
** up the shared-btree.
*/
assert( p->wantToLock==0 && p->locked==0 );
if( !p->sharable || removeFromSharingList(pBt) ){
/* The pBt is no longer on the sharing list, so we can access
** it without having to hold the mutex.
**
** Clean out and delete the BtShared object.
*/
assert( !pBt->pCursor );
sqlite3PagerClose(pBt->pPager);
if( pBt->xFreeSchema && pBt->pSchema ){
pBt->xFreeSchema(pBt->pSchema);
}
sqlite3_free(pBt->pSchema);
freeTempSpace(pBt);
sqlite3_free(pBt);
}
#ifndef SQLITE_OMIT_SHARED_CACHE
assert( p->wantToLock==0 );
assert( p->locked==0 );
if( p->pPrev ) p->pPrev->pNext = p->pNext;
if( p->pNext ) p->pNext->pPrev = p->pPrev;
#endif
sqlite3_free(p);
return SQLITE_OK;
}
/*
** Change the limit on the number of pages allowed in the cache.
sqlite-amalgamation.c view on Meta::CPAN
#endif
}
/*
** Get a reference to pPage1 of the database file. This will
** also acquire a readlock on that file.
**
** SQLITE_OK is returned on success. If the file is not a
** well-formed database file, then SQLITE_CORRUPT is returned.
** SQLITE_BUSY is returned if the database is locked. SQLITE_NOMEM
** is returned if we run out of memory.
*/
static int lockBtree(BtShared *pBt){
int rc;
MemPage *pPage1;
int nPage;
assert( sqlite3_mutex_held(pBt->mutex) );
if( pBt->pPage1 ) return SQLITE_OK;
rc = sqlite3BtreeGetPage(pBt, 1, &pPage1, 0);
sqlite-amalgamation.c view on Meta::CPAN
**
** sqlite3BtreeCreateTable()
** sqlite3BtreeCreateIndex()
** sqlite3BtreeClearTable()
** sqlite3BtreeDropTable()
** sqlite3BtreeInsert()
** sqlite3BtreeDelete()
** sqlite3BtreeUpdateMeta()
**
** If an initial attempt to acquire the lock fails because of lock contention
** and the database was previously unlocked, then invoke the busy handler
** if there is one. But if there was previously a read-lock, do not
** invoke the busy handler - just return SQLITE_BUSY. SQLITE_BUSY is
** returned when there is already a read-lock in order to avoid a deadlock.
**
** Suppose there are two processes A and B. A has a read lock and B has
** a reserved lock. B tries to promote to exclusive but is blocked because
** of A's read lock. A tries to promote to reserved but is blocked by B.
** One or the other of the two processes must give way or there can be
** no progress. By returning SQLITE_BUSY and not invoking the busy callback
** when A already has a read lock, we encourage A to give up and let B
** proceed.
*/
SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
BtShared *pBt = p->pBt;
int rc = SQLITE_OK;
sqlite3BtreeEnter(p);
sqlite-amalgamation.c view on Meta::CPAN
** Execute as much of a VDBE program as we can then return.
**
** sqlite3VdbeMakeReady() must be called before this routine in order to
** close the program with a final OP_Halt and to set up the callbacks
** and the error message pointer.
**
** Whenever a row or result data is available, this routine will either
** invoke the result callback (if there is one) or return with
** SQLITE_ROW.
**
** If an attempt is made to open a locked database, then this routine
** will either invoke the busy callback (if there is one) or it will
** return SQLITE_BUSY.
**
** If an error occurs, an error message is written to memory obtained
** from sqlite3_malloc() and p->zErrMsg is made to point to that memory.
** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
**
** If the callback ever returns non-zero, then the program exits
** immediately. There will be no error message but the p->rc field is
** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
sqlite-amalgamation.c view on Meta::CPAN
** P3==0 means the main database, P3==1 means the database used for
** temporary tables, and P3>1 means used the corresponding attached
** database. Give the new cursor an identifier of P1. The P1
** values need not be contiguous but all P1 values should be small integers.
** It is an error for P1 to be negative.
**
** If P5!=0 then use the content of register P2 as the root page, not
** the value of P2 itself.
**
** There will be a read lock on the database whenever there is an
** open cursor. If the database was unlocked prior to this instruction
** then a read lock is acquired as part of this instruction. A read
** lock allows other processes to read the database but prohibits
** any other process from modifying the database. The read lock is
** released when all cursors are closed. If this instruction attempts
** to get a read lock but fails, the script terminates with an
** SQLITE_BUSY error code.
**
** The P4 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices. P4 is NULL for cursors
** that are not pointing to indices.
sqlite-amalgamation.c view on Meta::CPAN
**
** Obtain a lock on a particular table. This instruction is only used when
** the shared-cache feature is enabled.
**
** If P1 is the index of the database in sqlite3.aDb[] of the database
** on which the lock is acquired. A readlock is obtained if P3==0 or
** a write lock if P3==1.
**
** P2 contains the root-page of the table to lock.
**
** P4 contains a pointer to the name of the table being locked. This is only
** used to generate an error message if the lock cannot be obtained.
*/
case OP_TableLock: {
int p1 = pOp->p1;
u8 isWriteLock = pOp->p3;
assert( p1>=0 && p1<db->nDb );
assert( (p->btreeMask & (1<<p1))!=0 );
assert( isWriteLock==0 || isWriteLock==1 );
rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
if( rc==SQLITE_LOCKED ){
const char *z = pOp->p4.z;
sqlite3SetString(&p->zErrMsg, db, "database table is locked: %s", z);
}
break;
}
#endif /* SQLITE_OMIT_SHARED_CACHE */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VBegin * * * P4 *
**
** P4 may be a pointer to an sqlite3_vtab structure. If so, call the
** xBegin method for that table.
sqlite-amalgamation.c view on Meta::CPAN
if( i<2 ){
sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
goto detach_error;
}
if( !db->autoCommit ){
sqlite3_snprintf(sizeof(zErr), zErr,
"cannot DETACH database within transaction");
goto detach_error;
}
if( sqlite3BtreeIsInReadTrans(pDb->pBt) ){
sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
goto detach_error;
}
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
sqlite3ResetInternalSchema(db, 0);
return;
detach_error:
sqlite-amalgamation.c view on Meta::CPAN
pParse->explain = explainFlag;
pParse->nVar = 0;
}
#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** The TableLock structure is only used by the sqlite3TableLock() and
** codeTableLocks() functions.
*/
struct TableLock {
int iDb; /* The database containing the table to be locked */
int iTab; /* The root page of the table to be locked */
u8 isWriteLock; /* True for write lock. False for a read lock */
const char *zName; /* Name of the table */
};
/*
** Record the fact that we want to lock a table at run-time.
**
** The table to be locked has root page iTab and is found in database iDb.
** A read or a write lock can be taken depending on isWritelock.
**
** This routine just records the fact that the lock is desired. The
** code to make the lock occur is generated by a later call to
** codeTableLocks() which occurs during sqlite3FinishCoding().
*/
SQLITE_PRIVATE void sqlite3TableLock(
Parse *pParse, /* Parsing context */
int iDb, /* Index of the database containing the table to lock */
int iTab, /* Root page number of the table to be locked */
u8 isWriteLock, /* True for a write lock */
const char *zName /* Name of the table to be locked */
){
int i;
int nBytes;
TableLock *p;
if( iDb<0 ){
return;
}
for(i=0; i<pParse->nTableLock; i++){
sqlite-amalgamation.c view on Meta::CPAN
p->iTab = iTab;
p->isWriteLock = isWriteLock;
p->zName = zName;
}else{
pParse->nTableLock = 0;
pParse->db->mallocFailed = 1;
}
}
/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/
static void codeTableLocks(Parse *pParse){
int i;
Vdbe *pVdbe;
if( 0==(pVdbe = sqlite3GetVdbe(pParse)) ){
return;
}
sqlite-amalgamation.c view on Meta::CPAN
}
}else
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*
** Report the current state of file logs for all databases
*/
if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
static const char *const azLockName[] = {
"unlocked", "shared", "reserved", "pending", "exclusive"
};
int i;
Vdbe *v = sqlite3GetVdbe(pParse);
sqlite3VdbeSetNumCols(v, 2);
pParse->nMem = 2;
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC);
sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC);
for(i=0; i<db->nDb; i++){
Btree *pBt;
Pager *pPager;
sqlite-amalgamation.c view on Meta::CPAN
int i;
assert( ppStmt );
*ppStmt = 0;
if( sqlite3SafetyOn(db) ){
return SQLITE_MISUSE;
}
assert( !db->mallocFailed );
assert( sqlite3_mutex_held(db->mutex) );
/* If any attached database schemas are locked, do not proceed with
** compilation. Instead return SQLITE_LOCKED immediately.
*/
for(i=0; i<db->nDb; i++) {
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
int rc;
rc = sqlite3BtreeSchemaLocked(pBt);
if( rc ){
const char *zDb = db->aDb[i].zName;
sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
(void)sqlite3SafetyOff(db);
return sqlite3ApiExit(db, SQLITE_LOCKED);
}
}
}
memset(&sParse, 0, sizeof(sParse));
sParse.db = db;
if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
char *zSqlCopy;
sqlite-amalgamation.c view on Meta::CPAN
void (*xDestroy)(void *) /* Module destructor function */
){
return createModule(db, zName, pModule, pAux, xDestroy);
}
/*
** Lock the virtual table so that it cannot be disconnected.
** Locks nest. Every lock should have a corresponding unlock.
** If an unlock is omitted, resources leaks will occur.
**
** If a disconnect is attempted while a virtual table is locked,
** the disconnect is deferred until all locks have been removed.
*/
SQLITE_PRIVATE void sqlite3VtabLock(sqlite3_vtab *pVtab){
pVtab->nRef++;
}
/*
** Unlock a virtual table. When the last lock is removed,
** disconnect the virtual table.
*/
sqlite-amalgamation.c view on Meta::CPAN
*/
SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){
const char *z;
switch( rc & 0xff ){
case SQLITE_ROW:
case SQLITE_DONE:
case SQLITE_OK: z = "not an error"; break;
case SQLITE_ERROR: z = "SQL logic error or missing database"; break;
case SQLITE_PERM: z = "access permission denied"; break;
case SQLITE_ABORT: z = "callback requested query abort"; break;
case SQLITE_BUSY: z = "database is locked"; break;
case SQLITE_LOCKED: z = "database table is locked"; break;
case SQLITE_NOMEM: z = "out of memory"; break;
case SQLITE_READONLY: z = "attempt to write a readonly database"; break;
case SQLITE_INTERRUPT: z = "interrupted"; break;
case SQLITE_IOERR: z = "disk I/O error"; break;
case SQLITE_CORRUPT: z = "database disk image is malformed"; break;
case SQLITE_FULL: z = "database or disk is full"; break;
case SQLITE_CANTOPEN: z = "unable to open database file"; break;
case SQLITE_EMPTY: z = "table contains no data"; break;
case SQLITE_SCHEMA: z = "database schema has changed"; break;
case SQLITE_TOOBIG: z = "String or BLOB exceeded size limit"; break;
sqlite-amalgamation.c view on Meta::CPAN
values = (const char **) sqlite3_malloc(v->nColumn * sizeof(const char *));
for(i=0; i<v->nColumn; ++i){
if( sqlite3_column_type(s, i)==SQLITE_NULL ){
values[i] = NULL;
}else{
values[i] = string_dup((char*)sqlite3_column_text(s, i));
}
}
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_DONE ){
*pValues = values;
return SQLITE_OK;
}
freeStringArray(v->nColumn, values);
return rc;
}
sqlite-amalgamation.c view on Meta::CPAN
*/
static int content_exists(fulltext_vtab *v){
sqlite3_stmt *s;
int rc = sql_get_statement(v, CONTENT_EXISTS_STMT, &s);
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3_step(s);
if( rc!=SQLITE_ROW ) return rc;
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_DONE ) return SQLITE_ROW;
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
return rc;
}
/* insert into %_segments values ([pData])
** returns assigned blockid in *piBlockid
*/
static int block_insert(fulltext_vtab *v, const char *pData, int nData,
sqlite-amalgamation.c view on Meta::CPAN
/* NULL means that there were no inputs to max(). */
if( SQLITE_NULL==sqlite3_column_type(s, 0) ){
rc = sqlite3_step(s);
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
return rc;
}
*pidx = sqlite3_column_int(s, 0);
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
if( rc!=SQLITE_DONE ) return rc;
return SQLITE_ROW;
}
/* insert into %_segdir values (
** [iLevel], [idx],
** [iStartBlockid], [iLeavesEndBlockid], [iEndBlockid],
** [pRootData]
sqlite-amalgamation.c view on Meta::CPAN
rc = sqlite3_bind_int(s, 1, iLevel);
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3_step(s);
if( rc==SQLITE_DONE ) return SQLITE_DONE; /* Should never happen */
if( rc!=SQLITE_ROW ) return rc;
/* This happens if all segments at this level are entirely inline. */
if( SQLITE_NULL==sqlite3_column_type(s, 0) ){
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
int rc2 = sqlite3_step(s);
if( rc2==SQLITE_ROW ) return SQLITE_ERROR;
return rc2;
}
*piStartBlockid = sqlite3_column_int64(s, 0);
*piEndBlockid = sqlite3_column_int64(s, 1);
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
if( rc!=SQLITE_DONE ) return rc;
return SQLITE_ROW;
}
/* Delete the segment blocks and segment directory records for all
** segments at iLevel.
*/
static int segdir_delete(fulltext_vtab *v, int iLevel){
sqlite-amalgamation.c view on Meta::CPAN
*pnSegments = 0;
*piMaxLevel = 0;
return SQLITE_OK;
}
if( rc!=SQLITE_ROW ) return rc;
*pnSegments = sqlite3_column_int(s, 0);
*piMaxLevel = sqlite3_column_int(s, 1);
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_DONE ) return SQLITE_OK;
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
return rc;
}
/* TODO(shess) clearPendingTerms() is far down the file because
** writeZeroSegment() is far down the file because LeafWriter is far
** down the file. Consider refactoring the code to move the non-vtab
** code above the vtab code so that we don't need this forward
sqlite-amalgamation.c view on Meta::CPAN
rc = sqlite3_step(s);
if( rc==SQLITE_DONE ) return SQLITE_ERROR;
if( rc!=SQLITE_ROW ) return rc;
getChildrenContaining(sqlite3_column_blob(s, 0), sqlite3_column_bytes(s, 0),
pTerm, nTerm, isPrefix, piStartChild, piEndChild);
/* We expect only one row. We must execute another sqlite3_step()
* to complete the iteration; otherwise the table will remain
* locked. */
rc = sqlite3_step(s);
if( rc==SQLITE_ROW ) return SQLITE_ERROR;
if( rc!=SQLITE_DONE ) return rc;
return SQLITE_OK;
}
/* Traverse the tree represented by pData[nData] looking for
** pTerm[nTerm], placing its doclist into *out. This is internal to
** loadSegment() to make error-handling cleaner.
** New error codes may be added in future versions of SQLite.
**
** See also: [SQLITE_IOERR_READ | extended result codes]
*/
#define SQLITE_OK 0 /* Successful result */
/* beginning-of-error-codes */
#define SQLITE_ERROR 1 /* SQL error or missing database */
#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* The database file is locked */
#define SQLITE_LOCKED 6 /* A table in the database is locked */
#define SQLITE_NOMEM 7 /* A malloc() failed */
#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */
#define SQLITE_FULL 13 /* Insertion failed because database is full */
#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */
#define SQLITE_EMPTY 16 /* Database is empty */
** UTF-16 string in native byte order.
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);
/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400>
**
** This routine sets a callback function that might be invoked whenever
** an attempt is made to open a database table that another thread
** or process has locked.
**
** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock. If the busy callback
** is not NULL, then the callback will be invoked with two arguments.
**
** The first argument to the handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler(). The second argument to
** the handler callback is the number of times that the busy handler has
** been invoked for this locking event. If the
** busy callback returns 0, then no additional attempts are made to
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that it will be invoked
** when there is lock contention. If SQLite determines that invoking the busy
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock. The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first. If both processes
** invoke the busy handlers, neither will make any progress. Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** The default busy callback is NULL.
**
** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache. SQLite will
**
** {A12319} A busy handler must not close the database connection
** or [prepared statement] that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
/*
** CAPI3REF: Set A Busy Timeout {H12340} <S40410>
**
** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
** for a specified amount of time when a table is locked. The handler
** will sleep multiple times until at least "ms" milliseconds of sleeping
** have accumulated. {H12343} After "ms" milliseconds of sleeping,
** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** There can only be a single busy handler for a particular
** [database connection] any any given moment. If another busy handler
( run in 0.455 second using v1.01-cache-2.11-cpan-49f99fa48dc )