--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/persistentstorage/sql/SQLite/malloc.c Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,742 @@
+/*
+** 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.
+**
+** $Id: malloc.c,v 1.34 2008/08/05 17:53:23 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <stdarg.h>
+#include <ctype.h>
+
+/*
+** 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 inUse,
+ int allocSize
+){
+ sqlite3_release_memory(allocSize);
+}
+
+/*
+** Set the soft heap-size limit for the library. Passing a zero or
+** negative value indicates no limit.
+*/
+void sqlite3_soft_heap_limit(int n){
+ sqlite3_uint64 iLimit;
+ int overage;
+ if( n<0 ){
+ iLimit = 0;
+ }else{
+ iLimit = n;
+ }
+ sqlite3_initialize();
+ if( iLimit>0 ){
+ sqlite3_memory_alarm(softHeapLimitEnforcer, 0, iLimit);
+ }else{
+ sqlite3_memory_alarm(0, 0, 0);
+ }
+ overage = sqlite3_memory_used() - n;
+ if( overage>0 ){
+ sqlite3_release_memory(overage);
+ }
+}
+
+/*
+** 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
+ int nRet = sqlite3VdbeReleaseMemory(n);
+ nRet += sqlite3PagerReleaseMemory(n-nRet);
+ return nRet;
+#else
+ return SQLITE_OK;
+#endif
+}
+
+/*
+** State information local to the memory allocation subsystem.
+*/
+static struct {
+ 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. The alarmBusy variable is set to prevent recursive
+ ** callbacks.
+ */
+ sqlite3_int64 alarmThreshold;
+ void (*alarmCallback)(void*, sqlite3_int64,int);
+ void *alarmArg;
+ int alarmBusy;
+
+ /*
+ ** Pointers to the end of sqlite3Config.pScratch and
+ ** sqlite3Config.pPage to a block of memory that records
+ ** which pages are available.
+ */
+ u32 *aScratchFree;
+ u32 *aPageFree;
+
+ /* Number of free pages for scratch and page-cache memory */
+ u32 nScratchFree;
+ u32 nPageFree;
+} mem0;
+
+/*
+** Initialize the memory allocation subsystem.
+*/
+int sqlite3MallocInit(void){
+ if( sqlite3Config.m.xMalloc==0 ){
+ sqlite3MemSetDefault();
+ }
+ memset(&mem0, 0, sizeof(mem0));
+ if( sqlite3Config.bCoreMutex ){
+ mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+ }
+ if( sqlite3Config.pScratch && sqlite3Config.szScratch>=100
+ && sqlite3Config.nScratch>=0 ){
+ int i;
+ sqlite3Config.szScratch -= 4;
+ mem0.aScratchFree = (u32*)&((char*)sqlite3Config.pScratch)
+ [sqlite3Config.szScratch*sqlite3Config.nScratch];
+ for(i=0; i<sqlite3Config.nScratch; i++){ mem0.aScratchFree[i] = i; }
+ mem0.nScratchFree = sqlite3Config.nScratch;
+ }else{
+ sqlite3Config.pScratch = 0;
+ sqlite3Config.szScratch = 0;
+ }
+ if( sqlite3Config.pPage && sqlite3Config.szPage>=512
+ && sqlite3Config.nPage>=1 ){
+ int i;
+ int overhead;
+ int sz = sqlite3Config.szPage;
+ int n = sqlite3Config.nPage;
+ overhead = (4*n + sz - 1)/sz;
+ sqlite3Config.nPage -= overhead;
+ mem0.aPageFree = (u32*)&((char*)sqlite3Config.pPage)
+ [sqlite3Config.szPage*sqlite3Config.nPage];
+ for(i=0; i<sqlite3Config.nPage; i++){ mem0.aPageFree[i] = i; }
+ mem0.nPageFree = sqlite3Config.nPage;
+ }else{
+ sqlite3Config.pPage = 0;
+ sqlite3Config.szPage = 0;
+ }
+ return sqlite3Config.m.xInit(sqlite3Config.m.pAppData);
+}
+
+/*
+** Deinitialize the memory allocation subsystem.
+*/
+void sqlite3MallocEnd(void){
+ sqlite3Config.m.xShutdown(sqlite3Config.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;
+}
+
+/*
+** Change the alarm callback
+*/
+int sqlite3_memory_alarm(
+ void(*xCallback)(void *pArg, sqlite3_int64 used,int N),
+ void *pArg,
+ sqlite3_int64 iThreshold
+){
+ sqlite3_mutex_enter(mem0.mutex);
+ mem0.alarmCallback = xCallback;
+ mem0.alarmArg = pArg;
+ mem0.alarmThreshold = iThreshold;
+ sqlite3_mutex_leave(mem0.mutex);
+ return SQLITE_OK;
+}
+
+/*
+** Trigger the alarm
+*/
+static void sqlite3MallocAlarm(int nByte){
+ void (*xCallback)(void*,sqlite3_int64,int);
+ sqlite3_int64 nowUsed;
+ void *pArg;
+ if( mem0.alarmCallback==0 || mem0.alarmBusy ) return;
+ mem0.alarmBusy = 1;
+ xCallback = mem0.alarmCallback;
+ nowUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+ pArg = mem0.alarmArg;
+ sqlite3_mutex_leave(mem0.mutex);
+ xCallback(pArg, nowUsed, nByte);
+ sqlite3_mutex_enter(mem0.mutex);
+ mem0.alarmBusy = 0;
+}
+
+/*
+** 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 = sqlite3Config.m.xRoundup(n);
+ sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, n);
+ if( mem0.alarmCallback!=0 ){
+ int nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);
+ if( nUsed+nFull >= mem0.alarmThreshold ){
+ sqlite3MallocAlarm(nFull);
+ }
+ }
+ p = sqlite3Config.m.xMalloc(nFull);
+ if( p==0 && mem0.alarmCallback ){
+ sqlite3MallocAlarm(nFull);
+ p = sqlite3Config.m.xMalloc(nFull);
+ }
+ if( p ){
+ nFull = sqlite3MallocSize(p);
+ sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nFull);
+ }
+ *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 ){
+ p = 0;
+ }else if( sqlite3Config.bMemstat ){
+ sqlite3_mutex_enter(mem0.mutex);
+ mallocWithAlarm(n, &p);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ p = sqlite3Config.m.xMalloc(n);
+ }
+ 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 );
+
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+ /* Verify that no more than one 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==0 );
+#endif
+
+ if( sqlite3Config.szScratch<n ){
+ goto scratch_overflow;
+ }else{
+ sqlite3_mutex_enter(mem0.mutex);
+ if( mem0.nScratchFree==0 ){
+ sqlite3_mutex_leave(mem0.mutex);
+ goto scratch_overflow;
+ }else{
+ int i;
+ i = mem0.aScratchFree[--mem0.nScratchFree];
+ sqlite3_mutex_leave(mem0.mutex);
+ i *= sqlite3Config.szScratch;
+ sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, 1);
+ sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+ p = (void*)&((char*)sqlite3Config.pScratch)[i];
+ }
+ }
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+ scratchAllocOut = p!=0;
+#endif
+
+ return p;
+
+scratch_overflow:
+ if( sqlite3Config.bMemstat ){
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusSet(SQLITE_STATUS_SCRATCH_SIZE, n);
+ n = mallocWithAlarm(n, &p);
+ if( p ) sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, n);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ p = sqlite3Config.m.xMalloc(n);
+ }
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+ scratchAllocOut = p!=0;
+#endif
+ return p;
+}
+void sqlite3ScratchFree(void *p){
+ if( p ){
+
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+ /* Verify that no more than one 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 = 0;
+#endif
+
+ if( sqlite3Config.pScratch==0
+ || p<sqlite3Config.pScratch
+ || p>=(void*)mem0.aScratchFree ){
+ if( sqlite3Config.bMemstat ){
+ int iSize = sqlite3MallocSize(p);
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_OVERFLOW, -iSize);
+ sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize);
+ sqlite3Config.m.xFree(p);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ sqlite3Config.m.xFree(p);
+ }
+ }else{
+ int i;
+ i = (u8 *)p - (u8 *)sqlite3Config.pScratch;
+ i /= sqlite3Config.szScratch;
+ assert( i>=0 && i<sqlite3Config.nScratch );
+ sqlite3_mutex_enter(mem0.mutex);
+ assert( mem0.nScratchFree<sqlite3Config.nScratch );
+ mem0.aScratchFree[mem0.nScratchFree++] = i;
+ sqlite3StatusAdd(SQLITE_STATUS_SCRATCH_USED, -1);
+ sqlite3_mutex_leave(mem0.mutex);
+ }
+ }
+}
+
+/*
+** Allocate memory to be used by the page cache. Make use of the
+** memory buffer provided by SQLITE_CONFIG_PAGECACHE if there is one
+** and that memory is of the right size and is not completely
+** consumed. Otherwise, failover to sqlite3Malloc().
+*/
+void *sqlite3PageMalloc(int n){
+ void *p;
+ assert( n>0 );
+ assert( (n & (n-1))==0 );
+ assert( n>=512 && n<=32768 );
+
+ if( sqlite3Config.szPage<n ){
+ goto page_overflow;
+ }else{
+ sqlite3_mutex_enter(mem0.mutex);
+ if( mem0.nPageFree==0 ){
+ sqlite3_mutex_leave(mem0.mutex);
+ goto page_overflow;
+ }else{
+ int i;
+ i = mem0.aPageFree[--mem0.nPageFree];
+ sqlite3_mutex_leave(mem0.mutex);
+ i *= sqlite3Config.szPage;
+ sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, n);
+ sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, 1);
+ p = (void*)&((char*)sqlite3Config.pPage)[i];
+ }
+ }
+ return p;
+
+page_overflow:
+ if( sqlite3Config.bMemstat ){
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusSet(SQLITE_STATUS_PAGECACHE_SIZE, n);
+ n = mallocWithAlarm(n, &p);
+ if( p ) sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, n);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ p = sqlite3Config.m.xMalloc(n);
+ }
+ return p;
+}
+void sqlite3PageFree(void *p){
+ if( p ){
+ if( sqlite3Config.pPage==0
+ || p<sqlite3Config.pPage
+ || p>=(void*)mem0.aPageFree ){
+ /* In this case, the page allocation was obtained from a regular
+ ** call to sqlite3_mem_methods.xMalloc() (a page-cache-memory
+ ** "overflow"). Free the block with sqlite3_mem_methods.xFree().
+ */
+ if( sqlite3Config.bMemstat ){
+ int iSize = sqlite3MallocSize(p);
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_OVERFLOW, -iSize);
+ sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -iSize);
+ sqlite3Config.m.xFree(p);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ sqlite3Config.m.xFree(p);
+ }
+ }else{
+ /* The page allocation was allocated from the sqlite3Config.pPage
+ ** buffer. In this case all that is add the index of the page in
+ ** the sqlite3Config.pPage array to the set of free indexes stored
+ ** in the mem0.aPageFree[] array.
+ */
+ int i;
+ i = (u8 *)p - (u8 *)sqlite3Config.pPage;
+ i /= sqlite3Config.szPage;
+ assert( i>=0 && i<sqlite3Config.nPage );
+ sqlite3_mutex_enter(mem0.mutex);
+ assert( mem0.nPageFree<sqlite3Config.nPage );
+ mem0.aPageFree[mem0.nPageFree++] = i;
+ sqlite3StatusAdd(SQLITE_STATUS_PAGECACHE_USED, -1);
+ sqlite3_mutex_leave(mem0.mutex);
+#if !defined(NDEBUG) && 0
+ /* Assert that a duplicate was not just inserted into aPageFree[]. */
+ for(i=0; i<mem0.nPageFree-1; i++){
+ assert( mem0.aPageFree[i]!=mem0.aPageFree[mem0.nPageFree-1] );
+ }
+#endif
+ }
+ }
+}
+
+/*
+** TRUE if p is a lookaside memory allocation from db
+*/
+static int isLookaside(sqlite3 *db, void *p){
+ return db && p && p>=db->lookaside.pStart && p<db->lookaside.pEnd;
+}
+
+/*
+** Return the size of a memory allocation previously obtained from
+** sqlite3Malloc() or sqlite3_malloc().
+*/
+int sqlite3MallocSize(void *p){
+ return sqlite3Config.m.xSize(p);
+}
+int sqlite3DbMallocSize(sqlite3 *db, void *p){
+ if( isLookaside(db, p) ){
+ return db->lookaside.sz;
+ }else{
+ return sqlite3Config.m.xSize(p);
+ }
+}
+
+/*
+** Free memory previously obtained from sqlite3Malloc().
+*/
+void sqlite3_free(void *p){
+ if( p==0 ) return;
+ if( sqlite3Config.bMemstat ){
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, -sqlite3MallocSize(p));
+ sqlite3Config.m.xFree(p);
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ sqlite3Config.m.xFree(p);
+ }
+}
+
+/*
+** Free memory that might be associated with a particular database
+** connection.
+*/
+void sqlite3DbFree(sqlite3 *db, void *p){
+ if( isLookaside(db, p) ){
+ LookasideSlot *pBuf = (LookasideSlot*)p;
+ pBuf->pNext = db->lookaside.pFree;
+ db->lookaside.pFree = pBuf;
+ db->lookaside.nOut--;
+ }else{
+ sqlite3_free(p);
+ }
+}
+
+/*
+** Change the size of an existing memory allocation
+*/
+void *sqlite3Realloc(void *pOld, int nBytes){
+ int nOld, nNew;
+ void *pNew;
+ if( pOld==0 ){
+ return sqlite3Malloc(nBytes);
+ }
+ if( nBytes<=0 ){
+ sqlite3_free(pOld);
+ return 0;
+ }
+ nOld = sqlite3MallocSize(pOld);
+ if( sqlite3Config.bMemstat ){
+ sqlite3_mutex_enter(mem0.mutex);
+ sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, nBytes);
+ nNew = sqlite3Config.m.xRoundup(nBytes);
+ if( nOld==nNew ){
+ pNew = pOld;
+ }else{
+ if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)+nNew-nOld >=
+ mem0.alarmThreshold ){
+ sqlite3MallocAlarm(nNew-nOld);
+ }
+ pNew = sqlite3Config.m.xRealloc(pOld, nNew);
+ if( pNew==0 && mem0.alarmCallback ){
+ sqlite3MallocAlarm(nBytes);
+ pNew = sqlite3Config.m.xRealloc(pOld, nNew);
+ }
+ if( pNew ){
+ nNew = sqlite3MallocSize(pNew);
+ sqlite3StatusAdd(SQLITE_STATUS_MEMORY_USED, nNew-nOld);
+ }
+ }
+ sqlite3_mutex_leave(mem0.mutex);
+ }else{
+ pNew = sqlite3Config.m.xRealloc(pOld, nBytes);
+ }
+ 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.
+*/
+void *sqlite3DbMallocRaw(sqlite3 *db, int n){
+ void *p;
+ if( db ){
+ LookasideSlot *pBuf;
+ if( db->mallocFailed ){
+ return 0;
+ }
+ if( db->lookaside.bEnabled && n<=db->lookaside.sz
+ && (pBuf = db->lookaside.pFree)!=0 ){
+ db->lookaside.pFree = pBuf->pNext;
+ db->lookaside.nOut++;
+ if( db->lookaside.nOut>db->lookaside.mxOut ){
+ db->lookaside.mxOut = db->lookaside.nOut;
+ }
+ return (void*)pBuf;
+ }
+ }
+ p = sqlite3Malloc(n);
+ if( !p && db ){
+ db->mallocFailed = 1;
+ }
+ 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;
+ 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{
+ pNew = sqlite3_realloc(p, n);
+ if( !pNew ){
+ db->mallocFailed = 1;
+ }
+ }
+ }
+ 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 = strlen(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 occured since the previous
+** invocation SQLITE_NOMEM is returned instead.
+**
+** If the first argument, db, is not NULL and a malloc() error has occured,
+** 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 ){
+ sqlite3Error(db, SQLITE_NOMEM, 0);
+ db->mallocFailed = 0;
+ rc = SQLITE_NOMEM;
+ }
+ return rc & (db ? db->errMask : 0xff);
+}