/* ** 2001 September 15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** Memory allocation functions used throughout sqlite. */ #include "sqliteInt.h" #include /* ** Attempt to release up to n bytes of non-essential memory currently ** held by SQLite. An example of non-essential memory is memory used to ** cache database pages that are not currently in use. */ int sqlite3_release_memory(int n){ #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT return sqlite3PcacheReleaseMemory(n); #else /* IMPLEMENTATION-OF: R-34391-24921 The sqlite3_release_memory() routine ** is a no-op returning zero if SQLite is not compiled with ** SQLITE_ENABLE_MEMORY_MANAGEMENT. */ UNUSED_PARAMETER(n); return 0; #endif } /* ** An instance of the following object records the location of ** each unused scratch buffer. */ typedef struct ScratchFreeslot { struct ScratchFreeslot *pNext; /* Next unused scratch buffer */ } ScratchFreeslot; /* ** State information local to the memory allocation subsystem. */ static SQLITE_WSD struct Mem0Global { sqlite3_mutex *mutex; /* Mutex to serialize access */ /* ** The alarm callback and its arguments. The mem0.mutex lock will ** be held while the callback is running. Recursive calls into ** the memory subsystem are allowed, but no new callbacks will be ** issued. */ sqlite3_int64 alarmThreshold; void (*alarmCallback)(void*, sqlite3_int64,int); void *alarmArg; /* ** Pointers to the end of sqlite3GlobalConfig.pScratch memory ** (so that a range test can be used to determine if an allocation ** being freed came from pScratch) and a pointer to the list of ** unused scratch allocations. */ void *pScratchEnd; ScratchFreeslot *pScratchFree; u32 nScratchFree; /* ** True if heap is nearly "full" where "full" is defined by the ** sqlite3_soft_heap_limit() setting. */ int nearlyFull; } mem0 = { 0, 0, 0, 0, 0, 0, 0, 0 }; #define mem0 GLOBAL(struct Mem0Global, mem0) /* ** This routine runs when the memory allocator sees that the ** total memory allocation is about to exceed the soft heap ** limit. */ static void softHeapLimitEnforcer( void *NotUsed, sqlite3_int64 NotUsed2, int allocSize ){ UNUSED_PARAMETER2(NotUsed, NotUsed2); sqlite3_release_memory(allocSize); } /* ** Change the alarm callback */ static int sqlite3MemoryAlarm( void(*xCallback)(void *pArg, sqlite3_int64 used,int N), void *pArg, sqlite3_int64 iThreshold ){ int nUsed; sqlite3_mutex_enter(mem0.mutex); mem0.alarmCallback = xCallback; mem0.alarmArg = pArg; mem0.alarmThreshold = iThreshold; nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); mem0.nearlyFull = (iThreshold>0 && iThreshold<=nUsed); sqlite3_mutex_leave(mem0.mutex); return SQLITE_OK; } #ifndef SQLITE_OMIT_DEPRECATED /* ** Deprecated external interface. Internal/core SQLite code ** should call sqlite3MemoryAlarm. */ int sqlite3_memory_alarm( void(*xCallback)(void *pArg, sqlite3_int64 used,int N), void *pArg, sqlite3_int64 iThreshold ){ return sqlite3MemoryAlarm(xCallback, pArg, iThreshold); } #endif /* ** Set the soft heap-size limit for the library. Passing a zero or ** negative value indicates no limit. */ sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){ sqlite3_int64 priorLimit; sqlite3_int64 excess; #ifndef SQLITE_OMIT_AUTOINIT int rc = sqlite3_initialize(); if( rc ) return -1; #endif sqlite3_mutex_enter(mem0.mutex); priorLimit = mem0.alarmThreshold; sqlite3_mutex_leave(mem0.mutex); if( n<0 ) return priorLimit; if( n>0 ){ sqlite3MemoryAlarm(softHeapLimitEnforcer, 0, n); }else{ sqlite3MemoryAlarm(0, 0, 0); } excess = sqlite3_memory_used() - n; if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff)); return priorLimit; } void sqlite3_soft_heap_limit(int n){ if( n<0 ) n = 0; sqlite3_soft_heap_limit64(n); } /* ** Initialize the memory allocation subsystem. */ int sqlite3MallocInit(void){ if( sqlite3GlobalConfig.m.xMalloc==0 ){ sqlite3MemSetDefault(); } memset(&mem0, 0, sizeof(mem0)); if( sqlite3GlobalConfig.bCoreMutex ){ mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); } if( sqlite3GlobalConfig.pScratch && sqlite3GlobalConfig.szScratch>=100 && sqlite3GlobalConfig.nScratch>0 ){ int i, n, sz; ScratchFreeslot *pSlot; sz = ROUNDDOWN8(sqlite3GlobalConfig.szScratch); sqlite3GlobalConfig.szScratch = sz; pSlot = (ScratchFreeslot*)sqlite3GlobalConfig.pScratch; n = sqlite3GlobalConfig.nScratch; mem0.pScratchFree = pSlot; mem0.nScratchFree = n; for(i=0; ipNext = (ScratchFreeslot*)(sz+(char*)pSlot); pSlot = pSlot->pNext; } pSlot->pNext = 0; mem0.pScratchEnd = (void*)&pSlot[1]; }else{ mem0.pScratchEnd = 0; sqlite3GlobalConfig.pScratch = 0; sqlite3GlobalConfig.szScratch = 0; sqlite3GlobalConfig.nScratch = 0; } if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512 || sqlite3GlobalConfig.nPage<1 ){ sqlite3GlobalConfig.pPage = 0; sqlite3GlobalConfig.szPage = 0; sqlite3GlobalConfig.nPage = 0; } return sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData); } /* ** Return true if the heap is currently under memory pressure - in other ** words if the amount of heap used is close to the limit set by ** sqlite3_soft_heap_limit(). */ int sqlite3HeapNearlyFull(void){ return mem0.nearlyFull; } /* ** Deinitialize the memory allocation subsystem. */ void sqlite3MallocEnd(void){ if( sqlite3GlobalConfig.m.xShutdown ){ sqlite3GlobalConfig.m.xShutdown(sqlite3GlobalConfig.m.pAppData); } memset(&mem0, 0, sizeof(mem0)); } /* ** Return the amount of memory currently checked out. */ sqlite3_int64 sqlite3_memory_used(void){ int n, mx; sqlite3_int64 res; sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, 0); res = (sqlite3_int64)n; /* Work around bug in Borland C. Ticket #3216 */ return res; } /* ** Return the maximum amount of memory that has ever been ** checked out since either the beginning of this process ** or since the most recent reset. */ sqlite3_int64 sqlite3_memory_highwater(int resetFlag){ int n, mx; sqlite3_int64 res; sqlite3_status(SQLITE_STATUS_MEMORY_USED, &n, &mx, resetFlag); res = (sqlite3_int64)mx; /* Work around bug in Borland C. Ticket #3216 */ return res; } /* ** Trigger the alarm */ static void sqlite3MallocAlarm(int nByte){ void (*xCallback)(void*,sqlite3_int64,int); sqlite3_int64 nowUsed; void *pArg; if( mem0.alarmCallback==0 ) return; xCallback = mem0.alarmCallback; nowUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); pArg = mem0.alarmArg; mem0.alarmCallback = 0; sqlite3_mutex_leave(mem0.mutex); xCallback(pArg, nowUsed, nByte); sqlite3_mutex_enter(mem0.mutex); mem0.alarmCallback = xCallback; mem0.alarmArg = pArg; } /* ** Do a memory allocation with statistics and alarms. Assume the ** lock is already held. */ static int mallocWithAlarm(int n, void **pp){ int nFull; void *p; assert( sqlite3_mutex_held(mem0.mutex) ); nFull = sqlite3GlobalConfig.m.xRoundup(n); sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n); if( mem0.alarmCallback!=0 ){ int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED); if( nUsed >= mem0.alarmThreshold - nFull ){ mem0.nearlyFull = 1; sqlite3MallocAlarm(nFull); }else{ mem0.nearlyFull = 0; } } p = sqlite3GlobalConfig.m.xMalloc(nFull); #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT if( p==0 && mem0.alarmCallback ){ sqlite3MallocAlarm(nFull); p = sqlite3GlobalConfig.m.xMalloc(nFull); } #endif if( p ){ nFull = sqlite3MallocSize(p); sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull); sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, 1); } *pp = p; return nFull; } /* ** Allocate memory. This routine is like sqlite3_malloc() except that it ** assumes the memory subsystem has already been initialized. */ void *sqlite3Malloc(int n){ void *p; if( n<=0 /* IMP: R-65312-04917 */ || n>=0x7fffff00 ){ /* A memory allocation of a number of bytes which is near the maximum ** signed integer value might cause an integer overflow inside of the ** xMalloc(). Hence we limit the maximum size to 0x7fffff00, giving ** 255 bytes of overhead. SQLite itself will never use anything near ** this amount. The only way to reach the limit is with sqlite3_malloc() */ p = 0; }else if( sqlite3GlobalConfig.bMemstat ){ sqlite3_mutex_enter(mem0.mutex); mallocWithAlarm(n, &p); sqlite3_mutex_leave(mem0.mutex); }else{ p = sqlite3GlobalConfig.m.xMalloc(n); } assert( EIGHT_BYTE_ALIGNMENT(p) ); /* IMP: R-04675-44850 */ return p; } /* ** This version of the memory allocation is for use by the application. ** First make sure the memory subsystem is initialized, then do the ** allocation. */ void *sqlite3_malloc(int n){ #ifndef SQLITE_OMIT_AUTOINIT if( sqlite3_initialize() ) return 0; #endif return sqlite3Malloc(n); } /* ** Each thread may only have a single outstanding allocation from ** xScratchMalloc(). We verify this constraint in the single-threaded ** case by setting scratchAllocOut to 1 when an allocation ** is outstanding clearing it when the allocation is freed. */ #if SQLITE_THREADSAFE==0 && !defined(NDEBUG) static int scratchAllocOut = 0; #endif /* ** Allocate memory that is to be used and released right away. ** This routine is similar to alloca() in that it is not intended ** for situations where the memory might be held long-term. This ** routine is intended to get memory to old large transient data ** structures that would not normally fit on the stack of an ** embedded processor. */ void *sqlite3ScratchMalloc(int n){ void *p; assert( n>0 ); sqlite3_mutex_enter(mem0.mutex); if( mem0.nScratchFree && sqlite3GlobalConfig.szScratch>=n ){ p = mem0.pScratchFree; mem0.pScratchFree = mem0.pScratchFree->pNext; mem0.nScratchFree--; sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1); sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n); sqlite3_mutex_leave(mem0.mutex); }else{ if( sqlite3GlobalConfig.bMemstat ){ sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n); n = mallocWithAlarm(n, &p); if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n); sqlite3_mutex_leave(mem0.mutex); }else{ sqlite3_mutex_leave(mem0.mutex); p = sqlite3GlobalConfig.m.xMalloc(n); } sqlite3MemdebugSetType(p, MEMTYPE_SCRATCH); } assert( sqlite3_mutex_notheld(mem0.mutex) ); #if SQLITE_THREADSAFE==0 && !defined(NDEBUG) /* Verify that no more than two scratch allocations per thread ** are outstanding at one time. (This is only checked in the ** single-threaded case since checking in the multi-threaded case ** would be much more complicated.) */ assert( scratchAllocOut<=1 ); if( p ) scratchAllocOut++; #endif return p; } void sqlite3ScratchFree(void *p){ if( p ){ #if SQLITE_THREADSAFE==0 && !defined(NDEBUG) /* Verify that no more than two scratch allocation per thread ** is outstanding at one time. (This is only checked in the ** single-threaded case since checking in the multi-threaded case ** would be much more complicated.) */ assert( scratchAllocOut>=1 && scratchAllocOut<=2 ); scratchAllocOut--; #endif if( p>=sqlite3GlobalConfig.pScratch && ppNext = mem0.pScratchFree; mem0.pScratchFree = pSlot; mem0.nScratchFree++; assert( mem0.nScratchFree <= (u32)sqlite3GlobalConfig.nScratch ); sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1); sqlite3_mutex_leave(mem0.mutex); }else{ /* Release memory back to the heap */ assert( sqlite3MemdebugHasType(p, MEMTYPE_SCRATCH) ); assert( sqlite3MemdebugNoType(p, ~MEMTYPE_SCRATCH) ); sqlite3MemdebugSetType(p, MEMTYPE_HEAP); if( sqlite3GlobalConfig.bMemstat ){ int iSize = sqlite3MallocSize(p); sqlite3_mutex_enter(mem0.mutex); sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, -iSize); sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize); sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, -1); sqlite3GlobalConfig.m.xFree(p); sqlite3_mutex_leave(mem0.mutex); }else{ sqlite3GlobalConfig.m.xFree(p); } } } } /* ** TRUE if p is a lookaside memory allocation from db */ #ifndef SQLITE_OMIT_LOOKASIDE static int isLookaside(sqlite3 *db, void *p){ return p && p>=db->lookaside.pStart && plookaside.pEnd; } #else #define isLookaside(A,B) 0 #endif /* ** Return the size of a memory allocation previously obtained from ** sqlite3Malloc() or sqlite3_malloc(). */ int sqlite3MallocSize(void *p){ assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) ); return sqlite3GlobalConfig.m.xSize(p); } int sqlite3DbMallocSize(sqlite3 *db, void *p){ assert( db==0 || sqlite3_mutex_held(db->mutex) ); if( db && isLookaside(db, p) ){ return db->lookaside.sz; }else{ assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) ); assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) ); assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) ); return sqlite3GlobalConfig.m.xSize(p); } } /* ** Free memory previously obtained from sqlite3Malloc(). */ void sqlite3_free(void *p){ if( p==0 ) return; /* IMP: R-49053-54554 */ assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) ); assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) ); if( sqlite3GlobalConfig.bMemstat ){ sqlite3_mutex_enter(mem0.mutex); sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -sqlite3MallocSize(p)); sqlite3StatusAdd(SQLITE_STATUS_MALLOC_COUNT, -1); sqlite3GlobalConfig.m.xFree(p); sqlite3_mutex_leave(mem0.mutex); }else{ sqlite3GlobalConfig.m.xFree(p); } } /* ** Free memory that might be associated with a particular database ** connection. */ void sqlite3DbFree(sqlite3 *db, void *p){ assert( db==0 || sqlite3_mutex_held(db->mutex) ); if( p==0 ) return; if( db ){ if( db->pnBytesFreed ){ *db->pnBytesFreed += sqlite3DbMallocSize(db, p); return; } if( isLookaside(db, p) ){ LookasideSlot *pBuf = (LookasideSlot*)p; #if SQLITE_DEBUG /* Trash all content in the buffer being freed */ memset(p, 0xaa, db->lookaside.sz); #endif pBuf->pNext = db->lookaside.pFree; db->lookaside.pFree = pBuf; db->lookaside.nOut--; return; } } assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) ); assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) ); assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) ); sqlite3MemdebugSetType(p, MEMTYPE_HEAP); sqlite3_free(p); } /* ** Change the size of an existing memory allocation */ void *sqlite3Realloc(void *pOld, int nBytes){ int nOld, nNew, nDiff; void *pNew; if( pOld==0 ){ return sqlite3Malloc(nBytes); /* IMP: R-28354-25769 */ } if( nBytes<=0 ){ sqlite3_free(pOld); /* IMP: R-31593-10574 */ return 0; } if( nBytes>=0x7fffff00 ){ /* The 0x7ffff00 limit term is explained in comments on sqlite3Malloc() */ return 0; } nOld = sqlite3MallocSize(pOld); /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second ** argument to xRealloc is always a value returned by a prior call to ** xRoundup. */ nNew = sqlite3GlobalConfig.m.xRoundup(nBytes); if( nOld==nNew ){ pNew = pOld; }else if( sqlite3GlobalConfig.bMemstat ){ sqlite3_mutex_enter(mem0.mutex); sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, nBytes); nDiff = nNew - nOld; if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= mem0.alarmThreshold-nDiff ){ sqlite3MallocAlarm(nDiff); } assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) ); assert( sqlite3MemdebugNoType(pOld, ~MEMTYPE_HEAP) ); pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); if( pNew==0 && mem0.alarmCallback ){ sqlite3MallocAlarm(nBytes); pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); } if( pNew ){ nNew = sqlite3MallocSize(pNew); sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nNew-nOld); } sqlite3_mutex_leave(mem0.mutex); }else{ pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew); } assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-04675-44850 */ return pNew; } /* ** The public interface to sqlite3Realloc. Make sure that the memory ** subsystem is initialized prior to invoking sqliteRealloc. */ void *sqlite3_realloc(void *pOld, int n){ #ifndef SQLITE_OMIT_AUTOINIT if( sqlite3_initialize() ) return 0; #endif return sqlite3Realloc(pOld, n); } /* ** Allocate and zero memory. */ void *sqlite3MallocZero(int n){ void *p = sqlite3Malloc(n); if( p ){ memset(p, 0, n); } return p; } /* ** Allocate and zero memory. If the allocation fails, make ** the mallocFailed flag in the connection pointer. */ void *sqlite3DbMallocZero(sqlite3 *db, int n){ void *p = sqlite3DbMallocRaw(db, n); if( p ){ memset(p, 0, n); } return p; } /* ** Allocate and zero memory. If the allocation fails, make ** the mallocFailed flag in the connection pointer. ** ** If db!=0 and db->mallocFailed is true (indicating a prior malloc ** failure on the same database connection) then always return 0. ** Hence for a particular database connection, once malloc starts ** failing, it fails consistently until mallocFailed is reset. ** This is an important assumption. There are many places in the ** code that do things like this: ** ** int *a = (int*)sqlite3DbMallocRaw(db, 100); ** int *b = (int*)sqlite3DbMallocRaw(db, 200); ** if( b ) a[10] = 9; ** ** In other words, if a subsequent malloc (ex: "b") worked, it is assumed ** that all prior mallocs (ex: "a") worked too. */ void *sqlite3DbMallocRaw(sqlite3 *db, int n){ void *p; assert( db==0 || sqlite3_mutex_held(db->mutex) ); assert( db==0 || db->pnBytesFreed==0 ); #ifndef SQLITE_OMIT_LOOKASIDE if( db ){ LookasideSlot *pBuf; if( db->mallocFailed ){ return 0; } if( db->lookaside.bEnabled ){ if( n>db->lookaside.sz ){ db->lookaside.anStat[1]++; }else if( (pBuf = db->lookaside.pFree)==0 ){ db->lookaside.anStat[2]++; }else{ db->lookaside.pFree = pBuf->pNext; db->lookaside.nOut++; db->lookaside.anStat[0]++; if( db->lookaside.nOut>db->lookaside.mxOut ){ db->lookaside.mxOut = db->lookaside.nOut; } return (void*)pBuf; } } } #else if( db && db->mallocFailed ){ return 0; } #endif p = sqlite3Malloc(n); if( !p && db ){ db->mallocFailed = 1; } sqlite3MemdebugSetType(p, MEMTYPE_DB | ((db && db->lookaside.bEnabled) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP)); return p; } /* ** Resize the block of memory pointed to by p to n bytes. If the ** resize fails, set the mallocFailed flag in the connection object. */ void *sqlite3DbRealloc(sqlite3 *db, void *p, int n){ void *pNew = 0; assert( db!=0 ); assert( sqlite3_mutex_held(db->mutex) ); if( db->mallocFailed==0 ){ if( p==0 ){ return sqlite3DbMallocRaw(db, n); } if( isLookaside(db, p) ){ if( n<=db->lookaside.sz ){ return p; } pNew = sqlite3DbMallocRaw(db, n); if( pNew ){ memcpy(pNew, p, db->lookaside.sz); sqlite3DbFree(db, p); } }else{ assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) ); assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) ); sqlite3MemdebugSetType(p, MEMTYPE_HEAP); pNew = sqlite3_realloc(p, n); if( !pNew ){ sqlite3MemdebugSetType(p, MEMTYPE_DB|MEMTYPE_HEAP); db->mallocFailed = 1; } sqlite3MemdebugSetType(pNew, MEMTYPE_DB | (db->lookaside.bEnabled ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP)); } } return pNew; } /* ** Attempt to reallocate p. If the reallocation fails, then free p ** and set the mallocFailed flag in the database connection. */ void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, int n){ void *pNew; pNew = sqlite3DbRealloc(db, p, n); if( !pNew ){ sqlite3DbFree(db, p); } return pNew; } /* ** Make a copy of a string in memory obtained from sqliteMalloc(). These ** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This ** is because when memory debugging is turned on, these two functions are ** called via macros that record the current file and line number in the ** ThreadData structure. */ char *sqlite3DbStrDup(sqlite3 *db, const char *z){ char *zNew; size_t n; if( z==0 ){ return 0; } n = sqlite3Strlen30(z) + 1; assert( (n&0x7fffffff)==n ); zNew = sqlite3DbMallocRaw(db, (int)n); if( zNew ){ memcpy(zNew, z, n); } return zNew; } char *sqlite3DbStrNDup(sqlite3 *db, const char *z, int n){ char *zNew; if( z==0 ){ return 0; } assert( (n&0x7fffffff)==n ); zNew = sqlite3DbMallocRaw(db, n+1); if( zNew ){ memcpy(zNew, z, n); zNew[n] = 0; } return zNew; } /* ** Create a string from the zFromat argument and the va_list that follows. ** Store the string in memory obtained from sqliteMalloc() and make *pz ** point to that string. */ void sqlite3SetString(char **pz, sqlite3 *db, const char *zFormat, ...){ va_list ap; char *z; va_start(ap, zFormat); z = sqlite3VMPrintf(db, zFormat, ap); va_end(ap); sqlite3DbFree(db, *pz); *pz = z; } /* ** This function must be called before exiting any API function (i.e. ** returning control to the user) that has called sqlite3_malloc or ** sqlite3_realloc. ** ** The returned value is normally a copy of the second argument to this ** function. However, if a malloc() failure has occurred since the previous ** invocation SQLITE_NOMEM is returned instead. ** ** If the first argument, db, is not NULL and a malloc() error has occurred, ** then the connection error-code (the value returned by sqlite3_errcode()) ** is set to SQLITE_NOMEM. */ int sqlite3ApiExit(sqlite3* db, int rc){ /* If the db handle is not NULL, then we must hold the connection handle ** mutex here. Otherwise the read (and possible write) of db->mallocFailed ** is unsafe, as is the call to sqlite3Error(). */ assert( !db || sqlite3_mutex_held(db->mutex) ); if( db && (db->mallocFailed || rc==SQLITE_IOERR_NOMEM) ){ sqlite3Error(db, SQLITE_NOMEM, 0); db->mallocFailed = 0; rc = SQLITE_NOMEM; } return rc & (db ? db->errMask : 0xff); }