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/*
** 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 <stdarg.h>
/*
** 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; i<n-1; i++){
pSlot->pNext = (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 && p<mem0.pScratchEnd ){
/* Release memory from the SQLITE_CONFIG_SCRATCH allocation */
ScratchFreeslot *pSlot;
pSlot = (ScratchFreeslot*)p;
sqlite3_mutex_enter(mem0.mutex);
pSlot->pNext = 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 && p<db->lookaside.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( 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);
}
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