DBD-SQLeet
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/*
** Powersafe overwrite is on by default. But can be turned off using
** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
*/
#ifndef SQLITE_POWERSAFE_OVERWRITE
# define SQLITE_POWERSAFE_OVERWRITE 1
#endif
/*
** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by
** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in
** which case memory allocation statistics are disabled by default.
*/
#if !defined(SQLITE_DEFAULT_MEMSTATUS)
# define SQLITE_DEFAULT_MEMSTATUS 1
#endif
/*
** Exactly one of the following macros must be defined in order to
** specify which memory allocation subsystem to use.
**
** SQLITE_SYSTEM_MALLOC // Use normal system malloc()
** SQLITE_WIN32_MALLOC // Use Win32 native heap API
** SQLITE_ZERO_MALLOC // Use a stub allocator that always fails
** SQLITE_MEMDEBUG // Debugging version of system malloc()
**
** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
** assert() macro is enabled, each call into the Win32 native heap subsystem
** will cause HeapValidate to be called. If heap validation should fail, an
** assertion will be triggered.
**
** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
** the default.
*/
#if defined(SQLITE_SYSTEM_MALLOC) \
+ defined(SQLITE_WIN32_MALLOC) \
+ defined(SQLITE_ZERO_MALLOC) \
+ defined(SQLITE_MEMDEBUG)>1
# error "Two or more of the following compile-time configuration options\
are defined but at most one is allowed:\
SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\
SQLITE_ZERO_MALLOC"
#endif
#if defined(SQLITE_SYSTEM_MALLOC) \
+ defined(SQLITE_WIN32_MALLOC) \
+ defined(SQLITE_ZERO_MALLOC) \
+ defined(SQLITE_MEMDEBUG)==0
# define SQLITE_SYSTEM_MALLOC 1
#endif
/*
** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
** sizes of memory allocations below this value where possible.
*/
#if !defined(SQLITE_MALLOC_SOFT_LIMIT)
# define SQLITE_MALLOC_SOFT_LIMIT 1024
#endif
/*
** We need to define _XOPEN_SOURCE as follows in order to enable
** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
** it.
*/
#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
# define _XOPEN_SOURCE 600
#endif
/*
** NDEBUG and SQLITE_DEBUG are opposites. It should always be true that
** defined(NDEBUG)==!defined(SQLITE_DEBUG). If this is not currently true,
** make it true by defining or undefining NDEBUG.
**
** Setting NDEBUG makes the code smaller and faster by disabling the
** assert() statements in the code. So we want the default action
** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
** is set. Thus NDEBUG becomes an opt-in rather than an opt-out
** feature.
*/
#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
# define NDEBUG 1
#endif
#if defined(NDEBUG) && defined(SQLITE_DEBUG)
# undef NDEBUG
#endif
/*
** Enable SQLITE_ENABLE_EXPLAIN_COMMENTS if SQLITE_DEBUG is turned on.
*/
#if !defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) && defined(SQLITE_DEBUG)
# define SQLITE_ENABLE_EXPLAIN_COMMENTS 1
#endif
/*
** The testcase() macro is used to aid in coverage testing. When
** doing coverage testing, the condition inside the argument to
** testcase() must be evaluated both true and false in order to
** get full branch coverage. The testcase() macro is inserted
** to help ensure adequate test coverage in places where simple
** condition/decision coverage is inadequate. For example, testcase()
** can be used to make sure boundary values are tested. For
** bitmask tests, testcase() can be used to make sure each bit
** is significant and used at least once. On switch statements
** where multiple cases go to the same block of code, testcase()
** can insure that all cases are evaluated.
**
*/
#ifdef SQLITE_COVERAGE_TEST
SQLITE_PRIVATE void sqlite3Coverage(int);
# define testcase(X) if( X ){ sqlite3Coverage(__LINE__); }
#else
# define testcase(X)
#endif
/*
** The TESTONLY macro is used to enclose variable declarations or
** other bits of code that are needed to support the arguments
** within testcase() and assert() macros.
*/
#if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
# define TESTONLY(X) X
{ "stat", (sqlite3_syscall_ptr)stat, 0 },
#define osStat ((int(*)(const char*,struct stat*))aSyscall[4].pCurrent)
/*
** The DJGPP compiler environment looks mostly like Unix, but it
** lacks the fcntl() system call. So redefine fcntl() to be something
** that always succeeds. This means that locking does not occur under
** DJGPP. But it is DOS - what did you expect?
*/
#ifdef __DJGPP__
{ "fstat", 0, 0 },
#define osFstat(a,b,c) 0
#else
{ "fstat", (sqlite3_syscall_ptr)fstat, 0 },
#define osFstat ((int(*)(int,struct stat*))aSyscall[5].pCurrent)
#endif
{ "ftruncate", (sqlite3_syscall_ptr)ftruncate, 0 },
#define osFtruncate ((int(*)(int,off_t))aSyscall[6].pCurrent)
{ "fcntl", (sqlite3_syscall_ptr)fcntl, 0 },
#define osFcntl ((int(*)(int,int,...))aSyscall[7].pCurrent)
{ "read", (sqlite3_syscall_ptr)read, 0 },
#define osRead ((ssize_t(*)(int,void*,size_t))aSyscall[8].pCurrent)
#if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE
{ "pread", (sqlite3_syscall_ptr)pread, 0 },
#else
{ "pread", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osPread ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[9].pCurrent)
#if defined(USE_PREAD64)
{ "pread64", (sqlite3_syscall_ptr)pread64, 0 },
#else
{ "pread64", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osPread64 ((ssize_t(*)(int,void*,size_t,off64_t))aSyscall[10].pCurrent)
{ "write", (sqlite3_syscall_ptr)write, 0 },
#define osWrite ((ssize_t(*)(int,const void*,size_t))aSyscall[11].pCurrent)
#if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE
{ "pwrite", (sqlite3_syscall_ptr)pwrite, 0 },
#else
{ "pwrite", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osPwrite ((ssize_t(*)(int,const void*,size_t,off_t))\
aSyscall[12].pCurrent)
#if defined(USE_PREAD64)
{ "pwrite64", (sqlite3_syscall_ptr)pwrite64, 0 },
#else
{ "pwrite64", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osPwrite64 ((ssize_t(*)(int,const void*,size_t,off64_t))\
aSyscall[13].pCurrent)
{ "fchmod", (sqlite3_syscall_ptr)fchmod, 0 },
#define osFchmod ((int(*)(int,mode_t))aSyscall[14].pCurrent)
#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
{ "fallocate", (sqlite3_syscall_ptr)posix_fallocate, 0 },
#else
{ "fallocate", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osFallocate ((int(*)(int,off_t,off_t))aSyscall[15].pCurrent)
{ "unlink", (sqlite3_syscall_ptr)unlink, 0 },
#define osUnlink ((int(*)(const char*))aSyscall[16].pCurrent)
{ "openDirectory", (sqlite3_syscall_ptr)openDirectory, 0 },
#define osOpenDirectory ((int(*)(const char*,int*))aSyscall[17].pCurrent)
{ "mkdir", (sqlite3_syscall_ptr)mkdir, 0 },
#define osMkdir ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)
{ "rmdir", (sqlite3_syscall_ptr)rmdir, 0 },
#define osRmdir ((int(*)(const char*))aSyscall[19].pCurrent)
#if defined(HAVE_FCHOWN)
{ "fchown", (sqlite3_syscall_ptr)fchown, 0 },
#else
{ "fchown", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osFchown ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)
#if defined(HAVE_FCHOWN)
{ "geteuid", (sqlite3_syscall_ptr)geteuid, 0 },
#else
{ "geteuid", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osGeteuid ((uid_t(*)(void))aSyscall[21].pCurrent)
#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
{ "mmap", (sqlite3_syscall_ptr)mmap, 0 },
#else
{ "mmap", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)
#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
{ "munmap", (sqlite3_syscall_ptr)munmap, 0 },
#else
{ "munmap", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osMunmap ((int(*)(void*,size_t))aSyscall[23].pCurrent)
#if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
{ "mremap", (sqlite3_syscall_ptr)mremap, 0 },
#else
{ "mremap", (sqlite3_syscall_ptr)0, 0 },
#endif
#define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)
#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
{ "getpagesize", (sqlite3_syscall_ptr)unixGetpagesize, 0 },
#else
{ "getpagesize", (sqlite3_syscall_ptr)0, 0 },
#endif
}
for(i++; i<ArraySize(aSyscall); i++){
if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
}
return 0;
}
/*
** Do not accept any file descriptor less than this value, in order to avoid
** opening database file using file descriptors that are commonly used for
** standard input, output, and error.
*/
#ifndef SQLITE_MINIMUM_FILE_DESCRIPTOR
# define SQLITE_MINIMUM_FILE_DESCRIPTOR 3
#endif
/*
** Invoke open(). Do so multiple times, until it either succeeds or
** fails for some reason other than EINTR.
**
** If the file creation mode "m" is 0 then set it to the default for
** SQLite. The default is SQLITE_DEFAULT_FILE_PERMISSIONS (normally
** 0644) as modified by the system umask. If m is not 0, then
** make the file creation mode be exactly m ignoring the umask.
**
** The m parameter will be non-zero only when creating -wal, -journal,
** and -shm files. We want those files to have *exactly* the same
** permissions as their original database, unadulterated by the umask.
** In that way, if a database file is -rw-rw-rw or -rw-rw-r-, and a
** transaction crashes and leaves behind hot journals, then any
** process that is able to write to the database will also be able to
** recover the hot journals.
*/
static int robust_open(const char *z, int f, mode_t m){
int fd;
mode_t m2 = m ? m : SQLITE_DEFAULT_FILE_PERMISSIONS;
while(1){
#if defined(O_CLOEXEC)
fd = osOpen(z,f|O_CLOEXEC,m2);
#else
fd = osOpen(z,f,m2);
#endif
if( fd<0 ){
if( errno==EINTR ) continue;
break;
}
if( fd>=SQLITE_MINIMUM_FILE_DESCRIPTOR ) break;
osClose(fd);
sqlite3_log(SQLITE_WARNING,
"attempt to open \"%s\" as file descriptor %d", z, fd);
fd = -1;
if( osOpen("/dev/null", f, m)<0 ) break;
}
if( fd>=0 ){
if( m!=0 ){
struct stat statbuf;
if( osFstat(fd, &statbuf)==0
&& statbuf.st_size==0
&& (statbuf.st_mode&0777)!=m
){
osFchmod(fd, m);
}
}
#if defined(FD_CLOEXEC) && (!defined(O_CLOEXEC) || O_CLOEXEC==0)
osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);
#endif
}
return fd;
}
/*
** Helper functions to obtain and relinquish the global mutex. The
** global mutex is used to protect the unixInodeInfo and
** vxworksFileId objects used by this file, all of which may be
** shared by multiple threads.
**
** Function unixMutexHeld() is used to assert() that the global mutex
** is held when required. This function is only used as part of assert()
** statements. e.g.
**
** unixEnterMutex()
** assert( unixMutexHeld() );
** unixEnterLeave()
**
** To prevent deadlock, the global unixBigLock must must be acquired
** before the unixInodeInfo.pLockMutex mutex, if both are held. It is
** OK to get the pLockMutex without holding unixBigLock first, but if
** that happens, the unixBigLock mutex must not be acquired until after
** pLockMutex is released.
**
** OK: enter(unixBigLock), enter(pLockInfo)
** OK: enter(unixBigLock)
** OK: enter(pLockInfo)
** ERROR: enter(pLockInfo), enter(unixBigLock)
*/
static sqlite3_mutex *unixBigLock = 0;
static void unixEnterMutex(void){
assert( sqlite3_mutex_notheld(unixBigLock) ); /* Not a recursive mutex */
sqlite3_mutex_enter(unixBigLock);
}
static void unixLeaveMutex(void){
assert( sqlite3_mutex_held(unixBigLock) );
sqlite3_mutex_leave(unixBigLock);
}
#ifdef SQLITE_DEBUG
static int unixMutexHeld(void) {
return sqlite3_mutex_held(unixBigLock);
}
#endif
#ifdef SQLITE_HAVE_OS_TRACE
/*
** Helper function for printing out trace information from debugging
** binaries. This returns the string representation of the supplied
** integer lock-type.
*/
static const char *azFileLock(int eFileLock){
switch( eFileLock ){
case NO_LOCK: return "NONE";
case SHARED_LOCK: return "SHARED";
goto end_takeconch;
}
}
/* if the conch isn't writable and doesn't match, we can't take it */
if( (conchFile->openFlags&O_RDWR) == 0 ){
rc = SQLITE_BUSY;
goto end_takeconch;
}
/* either the conch didn't match or we need to create a new one */
if( !pCtx->lockProxyPath ){
proxyGetLockPath(pCtx->dbPath, lockPath, MAXPATHLEN);
tempLockPath = lockPath;
/* create a copy of the lock path _only_ if the conch is taken */
}
/* update conch with host and path (this will fail if other process
** has a shared lock already), if the host id matches, use the big
** stick.
*/
futimes(conchFile->h, NULL);
if( hostIdMatch && !createConch ){
if( conchFile->pInode && conchFile->pInode->nShared>1 ){
/* We are trying for an exclusive lock but another thread in this
** same process is still holding a shared lock. */
rc = SQLITE_BUSY;
} else {
rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
}
}else{
rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);
}
if( rc==SQLITE_OK ){
char writeBuffer[PROXY_MAXCONCHLEN];
int writeSize = 0;
writeBuffer[0] = (char)PROXY_CONCHVERSION;
memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);
if( pCtx->lockProxyPath!=NULL ){
strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath,
MAXPATHLEN);
}else{
strlcpy(&writeBuffer[PROXY_PATHINDEX], tempLockPath, MAXPATHLEN);
}
writeSize = PROXY_PATHINDEX + strlen(&writeBuffer[PROXY_PATHINDEX]);
robust_ftruncate(conchFile->h, writeSize);
rc = unixWrite((sqlite3_file *)conchFile, writeBuffer, writeSize, 0);
full_fsync(conchFile->h,0,0);
/* If we created a new conch file (not just updated the contents of a
** valid conch file), try to match the permissions of the database
*/
if( rc==SQLITE_OK && createConch ){
struct stat buf;
int err = osFstat(pFile->h, &buf);
if( err==0 ){
mode_t cmode = buf.st_mode&(S_IRUSR|S_IWUSR | S_IRGRP|S_IWGRP |
S_IROTH|S_IWOTH);
/* try to match the database file R/W permissions, ignore failure */
#ifndef SQLITE_PROXY_DEBUG
osFchmod(conchFile->h, cmode);
#else
do{
rc = osFchmod(conchFile->h, cmode);
}while( rc==(-1) && errno==EINTR );
if( rc!=0 ){
int code = errno;
fprintf(stderr, "fchmod %o FAILED with %d %s\n",
cmode, code, strerror(code));
} else {
fprintf(stderr, "fchmod %o SUCCEDED\n",cmode);
}
}else{
int code = errno;
fprintf(stderr, "STAT FAILED[%d] with %d %s\n",
err, code, strerror(code));
#endif
}
}
}
conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);
end_takeconch:
OSTRACE(("TRANSPROXY: CLOSE %d\n", pFile->h));
if( rc==SQLITE_OK && pFile->openFlags ){
int fd;
if( pFile->h>=0 ){
robust_close(pFile, pFile->h, __LINE__);
}
pFile->h = -1;
fd = robust_open(pCtx->dbPath, pFile->openFlags, 0);
OSTRACE(("TRANSPROXY: OPEN %d\n", fd));
if( fd>=0 ){
pFile->h = fd;
}else{
rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called
during locking */
}
}
if( rc==SQLITE_OK && !pCtx->lockProxy ){
char *path = tempLockPath ? tempLockPath : pCtx->lockProxyPath;
rc = proxyCreateUnixFile(path, &pCtx->lockProxy, 1);
if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM && tryOldLockPath ){
/* we couldn't create the proxy lock file with the old lock file path
** so try again via auto-naming
*/
forceNewLockPath = 1;
tryOldLockPath = 0;
continue; /* go back to the do {} while start point, try again */
}
}
if( rc==SQLITE_OK ){
/* Need to make a copy of path if we extracted the value
** from the conch file or the path was allocated on the stack
*/
if( tempLockPath ){
pCtx->lockProxyPath = sqlite3DbStrDup(0, tempLockPath);
if( !pCtx->lockProxyPath ){
rc = SQLITE_NOMEM_BKPT;
}
}
}
if( rc==SQLITE_OK ){
pCtx->conchHeld = 1;
if( pCtx->lockProxy->pMethod == &afpIoMethods ){
afpLockingContext *afpCtx;
afpCtx = (afpLockingContext *)pCtx->lockProxy->lockingContext;
afpCtx->dbPath = pCtx->lockProxyPath;
}
} else {
**
** Precondition:
**
** The *-wal file has been read and an appropriate wal-index has been
** constructed in pWal->apWiData[] using heap memory instead of shared
** memory.
**
** If this function returns SQLITE_OK, then the read transaction has
** been successfully opened. In this case output variable (*pChanged)
** is set to true before returning if the caller should discard the
** contents of the page cache before proceeding. Or, if it returns
** WAL_RETRY, then the heap memory wal-index has been discarded and
** the caller should retry opening the read transaction from the
** beginning (including attempting to map the *-shm file).
**
** If an error occurs, an SQLite error code is returned.
*/
static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
i64 szWal; /* Size of wal file on disk in bytes */
i64 iOffset; /* Current offset when reading wal file */
u8 aBuf[WAL_HDRSIZE]; /* Buffer to load WAL header into */
u8 *aFrame = 0; /* Malloc'd buffer to load entire frame */
int szFrame; /* Number of bytes in buffer aFrame[] */
u8 *aData; /* Pointer to data part of aFrame buffer */
volatile void *pDummy; /* Dummy argument for xShmMap */
int rc; /* Return code */
u32 aSaveCksum[2]; /* Saved copy of pWal->hdr.aFrameCksum */
assert( pWal->bShmUnreliable );
assert( pWal->readOnly & WAL_SHM_RDONLY );
assert( pWal->nWiData>0 && pWal->apWiData[0] );
/* Take WAL_READ_LOCK(0). This has the effect of preventing any
** writers from running a checkpoint, but does not stop them
** from running recovery. */
rc = walLockShared(pWal, WAL_READ_LOCK(0));
if( rc!=SQLITE_OK ){
if( rc==SQLITE_BUSY ) rc = WAL_RETRY;
goto begin_unreliable_shm_out;
}
pWal->readLock = 0;
/* Check to see if a separate writer has attached to the shared-memory area,
** thus making the shared-memory "reliable" again. Do this by invoking
** the xShmMap() routine of the VFS and looking to see if the return
** is SQLITE_READONLY instead of SQLITE_READONLY_CANTINIT.
**
** If the shared-memory is now "reliable" return WAL_RETRY, which will
** cause the heap-memory WAL-index to be discarded and the actual
** shared memory to be used in its place.
**
** This step is important because, even though this connection is holding
** the WAL_READ_LOCK(0) which prevents a checkpoint, a writer might
** have already checkpointed the WAL file and, while the current
** is active, wrap the WAL and start overwriting frames that this
** process wants to use.
**
** Once sqlite3OsShmMap() has been called for an sqlite3_file and has
** returned any SQLITE_READONLY value, it must return only SQLITE_READONLY
** or SQLITE_READONLY_CANTINIT or some error for all subsequent invocations,
** even if some external agent does a "chmod" to make the shared-memory
** writable by us, until sqlite3OsShmUnmap() has been called.
** This is a requirement on the VFS implementation.
*/
rc = sqlite3OsShmMap(pWal->pDbFd, 0, WALINDEX_PGSZ, 0, &pDummy);
assert( rc!=SQLITE_OK ); /* SQLITE_OK not possible for read-only connection */
if( rc!=SQLITE_READONLY_CANTINIT ){
rc = (rc==SQLITE_READONLY ? WAL_RETRY : rc);
goto begin_unreliable_shm_out;
}
/* We reach this point only if the real shared-memory is still unreliable.
** Assume the in-memory WAL-index substitute is correct and load it
** into pWal->hdr.
*/
memcpy(&pWal->hdr, (void*)walIndexHdr(pWal), sizeof(WalIndexHdr));
/* Make sure some writer hasn't come in and changed the WAL file out
** from under us, then disconnected, while we were not looking.
*/
rc = sqlite3OsFileSize(pWal->pWalFd, &szWal);
if( rc!=SQLITE_OK ){
goto begin_unreliable_shm_out;
}
if( szWal<WAL_HDRSIZE ){
/* If the wal file is too small to contain a wal-header and the
** wal-index header has mxFrame==0, then it must be safe to proceed
** reading the database file only. However, the page cache cannot
** be trusted, as a read/write connection may have connected, written
** the db, run a checkpoint, truncated the wal file and disconnected
** since this client's last read transaction. */
*pChanged = 1;
rc = (pWal->hdr.mxFrame==0 ? SQLITE_OK : WAL_RETRY);
goto begin_unreliable_shm_out;
}
/* Check the salt keys at the start of the wal file still match. */
rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);
if( rc!=SQLITE_OK ){
goto begin_unreliable_shm_out;
}
if( memcmp(&pWal->hdr.aSalt, &aBuf[16], 8) ){
/* Some writer has wrapped the WAL file while we were not looking.
** Return WAL_RETRY which will cause the in-memory WAL-index to be
** rebuilt. */
rc = WAL_RETRY;
goto begin_unreliable_shm_out;
}
/* Allocate a buffer to read frames into */
szFrame = pWal->hdr.szPage + WAL_FRAME_HDRSIZE;
aFrame = (u8 *)sqlite3_malloc64(szFrame);
if( aFrame==0 ){
rc = SQLITE_NOMEM_BKPT;
goto begin_unreliable_shm_out;
}
aData = &aFrame[WAL_FRAME_HDRSIZE];
/* Check to see if a complete transaction has been appended to the
** wal file since the heap-memory wal-index was created. If so, the
** heap-memory wal-index is discarded and WAL_RETRY returned to
( run in 1.935 second using v1.01-cache-2.11-cpan-cdf2f3d4e48 )