/* Resize the hash table so that it cantains "new_size" buckets.
**
** The hash table might fail to resize if sqlite3_malloc() fails or
** if the new size is the same as the prior size.
** Return TRUE if the resize occurs and false if not.
*/
static int rehash(Hash *pH, unsigned int new_size){
struct _ht *new_ht; /* The new hash table */
HashElem *elem, *next_elem; /* For looping over existing elements */
#if SQLITE_MALLOC_SOFT_LIMIT>0
if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
}
if( new_size==pH->htsize ) return 0;
#endif
/* The inability to allocates space for a larger hash table is
** a performance hit but it is not a fatal error. So mark the
** allocation as a benign.
*/
sqlite3BeginBenignMalloc();
new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );
sqlite3EndBenignMalloc();
if( new_ht==0 ) return 0;
sqlite3_free(pH->ht);
pH->ht = new_ht;
pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);
memset(new_ht, 0, new_size*sizeof(struct _ht));
for(elem=pH->first, pH->first=0; elem; elem = next_elem){
unsigned int h = strHash(elem->pKey, elem->nKey) % new_size;
next_elem = elem->next;
insertElement(pH, &new_ht[h], elem);
}
return 1;
}
/*
** This function is used to resize the hash table used by the cache passed
** as the first argument.
**
** The PCache mutex must be held when this function is called.
*/
static void pcache1ResizeHash(PCache1 *p){
PgHdr1 **apNew;
unsigned int nNew;
unsigned int i;
assert( sqlite3_mutex_held(p->pGroup->mutex) );
nNew = p->nHash*2;
if( nNew<256 ){
nNew = 256;
}
pcache1LeaveMutex(p->pGroup);
if( p->nHash ){ sqlite3BeginBenignMalloc(); }
apNew = (PgHdr1 **)sqlite3MallocZero(sizeof(PgHdr1 *)*nNew);
if( p->nHash ){ sqlite3EndBenignMalloc(); }
pcache1EnterMutex(p->pGroup);
if( apNew ){
for(i=0; i<p->nHash; i++){
PgHdr1 *pPage;
PgHdr1 *pNext = p->apHash[i];
while( (pPage = pNext)!=0 ){
unsigned int h = pPage->iKey % nNew;
pNext = pPage->pNext;
pPage->pNext = apNew[h];
apNew[h] = pPage;
}
}
sqlite3_free(p->apHash);
p->apHash = apNew;
p->nHash = nNew;
}
}
/*
** Try to initialize the pCache->pFree and pCache->pBulk fields. Return
** true if pCache->pFree ends up containing one or more free pages.
*/
static int pcache1InitBulk(PCache1 *pCache){
i64 szBulk;
char *zBulk;
if( pcache1.nInitPage==0 ) return 0;
/* Do not bother with a bulk allocation if the cache size very small */
if( pCache->nMax<3 ) return 0;
sqlite3BeginBenignMalloc();
if( pcache1.nInitPage>0 ){
szBulk = pCache->szAlloc * (i64)pcache1.nInitPage;
}else{
szBulk = -1024 * (i64)pcache1.nInitPage;
}
if( szBulk > pCache->szAlloc*(i64)pCache->nMax ){
szBulk = pCache->szAlloc*pCache->nMax;
}
zBulk = pCache->pBulk = sqlite3Malloc( szBulk );
sqlite3EndBenignMalloc();
if( zBulk ){
int nBulk = sqlite3MallocSize(zBulk)/pCache->szAlloc;
int i;
for(i=0; i<nBulk; i++){
PgHdr1 *pX = (PgHdr1*)&zBulk[pCache->szPage];
pX->page.pBuf = zBulk;
pX->page.pExtra = &pX[1];
pX->isBulkLocal = 1;
pX->isAnchor = 0;
pX->pNext = pCache->pFree;
pCache->pFree = pX;
zBulk += pCache->szAlloc;
}
}
return pCache->pFree!=0;
}
/* Resize the hash table so that it cantains "new_size" buckets.
**
** The hash table might fail to resize if sqlite3_malloc() fails or
** if the new size is the same as the prior size.
** Return TRUE if the resize occurs and false if not.
*/
static int rehash(Hash *pH, unsigned int new_size){
struct _ht *new_ht; /* The new hash table */
HashElem *elem, *next_elem; /* For looping over existing elements */
#if SQLITE_MALLOC_SOFT_LIMIT>0
if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
}
if( new_size==pH->htsize ) return 0;
#endif
/* The inability to allocates space for a larger hash table is
** a performance hit but it is not a fatal error. So mark the
** allocation as a benign. Use sqlite3Malloc()/memset(0) instead of
** sqlite3MallocZero() to make the allocation, as sqlite3MallocZero()
** only zeroes the requested number of bytes whereas this module will
** use the actual amount of space allocated for the hash table (which
** may be larger than the requested amount).
*/
sqlite3BeginBenignMalloc();
new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );
sqlite3EndBenignMalloc();
if( new_ht==0 ) return 0;
sqlite3_free(pH->ht);
pH->ht = new_ht;
pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);
memset(new_ht, 0, new_size*sizeof(struct _ht));
for(elem=pH->first, pH->first=0; elem; elem = next_elem){
unsigned int h = strHash(elem->pKey, elem->nKey) % new_size;
next_elem = elem->next;
insertElement(pH, &new_ht[h], elem);
}
return 1;
}
/* Resize the hash table so that it cantains "new_size" buckets.
** "new_size" must be a power of 2. The hash table might fail
** to resize if sqlite3_malloc() fails.
*/
static void rehash(Hash *pH, int new_size){
struct _ht *new_ht; /* The new hash table */
HashElem *elem, *next_elem; /* For looping over existing elements */
#ifdef SQLITE_MALLOC_SOFT_LIMIT
if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){
new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);
}
if( new_size==pH->htsize ) return;
#endif
/* There is a call to sqlite3_malloc() inside rehash(). If there is
** already an allocation at pH->ht, then if this malloc() fails it
** is benign (since failing to resize a hash table is a performance
** hit only, not a fatal error).
*/
if( pH->htsize>0 ) sqlite3BeginBenignMalloc();
new_ht = (struct _ht *)sqlite3MallocZero( new_size*sizeof(struct _ht) );
if( pH->htsize>0 ) sqlite3EndBenignMalloc();
if( new_ht==0 ) return;
sqlite3_free(pH->ht);
pH->ht = new_ht;
pH->htsize = new_size;
for(elem=pH->first, pH->first=0; elem; elem = next_elem){
int h = strHash(elem->pKey, elem->nKey) & (new_size-1);
next_elem = elem->next;
insertElement(pH, &new_ht[h], elem);
}
}
static void test_agg_errmsg16_final(sqlite3_context *ctx){
#ifndef SQLITE_OMIT_UTF16
const void *z;
sqlite3 * db = sqlite3_context_db_handle(ctx);
sqlite3_aggregate_context(ctx, 2048);
sqlite3BeginBenignMalloc();
z = sqlite3_errmsg16(db);
sqlite3EndBenignMalloc();
sqlite3_result_text16(ctx, z, -1, SQLITE_TRANSIENT);
#endif
}
static int echoCommit(sqlite3_vtab *tab){
echo_vtab *pVtab = (echo_vtab*)tab;
int rc;
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xCommit") ){
return SQLITE_ERROR;
}
sqlite3BeginBenignMalloc();
rc = echoTransactionCall(tab, "xCommit");
sqlite3EndBenignMalloc();
pVtab->inTransaction = 0;
return rc;
}
/*
** Allocate a new page object initially associated with cache pCache.
*/
static PgHdr1 *pcache1AllocPage(PCache1 *pCache, int benignMalloc){
PgHdr1 *p = 0;
void *pPg;
assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
if( pCache->pFree || (pCache->nPage==0 && pcache1InitBulk(pCache)) ){
p = pCache->pFree;
pCache->pFree = p->pNext;
p->pNext = 0;
}else{
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/* The group mutex must be released before pcache1Alloc() is called. This
** is because it might call sqlite3_release_memory(), which assumes that
** this mutex is not held. */
assert( pcache1.separateCache==0 );
assert( pCache->pGroup==&pcache1.grp );
pcache1LeaveMutex(pCache->pGroup);
#endif
if( benignMalloc ){ sqlite3BeginBenignMalloc(); }
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
pPg = pcache1Alloc(pCache->szPage);
p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);
if( !pPg || !p ){
pcache1Free(pPg);
sqlite3_free(p);
pPg = 0;
}
#else
pPg = pcache1Alloc(pCache->szAlloc);
p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];
#endif
if( benignMalloc ){ sqlite3EndBenignMalloc(); }
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
pcache1EnterMutex(pCache->pGroup);
#endif
if( pPg==0 ) return 0;
p->page.pBuf = pPg;
p->page.pExtra = &p[1];
p->isBulkLocal = 0;
p->isAnchor = 0;
}
if( pCache->bPurgeable ){
pCache->pGroup->nCurrentPage++;
}
return p;
}
/*
** Allocate a new Explain object
*/
void sqlite3ExplainBegin(Vdbe *pVdbe){
if( pVdbe ){
Explain *p;
sqlite3BeginBenignMalloc();
p = (Explain *)sqlite3MallocZero( sizeof(Explain) );
if( p ){
p->pVdbe = pVdbe;
sqlite3_free(pVdbe->pExplain);
pVdbe->pExplain = p;
sqlite3StrAccumInit(&p->str, p->zBase, sizeof(p->zBase),
SQLITE_MAX_LENGTH);
p->str.useMalloc = 2;
}else{
sqlite3EndBenignMalloc();
}
}
}
/*
** Allocate a new Explain object
*/
void sqlite3ExplainBegin(Vdbe *pVdbe){
if( pVdbe ){
sqlite3BeginBenignMalloc();
Explain *p = sqlite3_malloc( sizeof(Explain) );
if( p ){
memset(p, 0, sizeof(*p));
p->pVdbe = pVdbe;
sqlite3_free(pVdbe->pExplain);
pVdbe->pExplain = p;
sqlite3StrAccumInit(&p->str, p->zBase, sizeof(p->zBase),
SQLITE_MAX_LENGTH);
p->str.useMalloc = 2;
}else{
sqlite3EndBenignMalloc();
}
}
}
static int echoCommit(sqlite3_vtab *tab){
echo_vtab *pVtab = (echo_vtab*)tab;
int rc;
/* Ticket #3083 - Only call xCommit if we have previously started
** a transaction */
assert( pVtab->inTransaction );
if( simulateVtabError(pVtab, "xCommit") ){
return SQLITE_ERROR;
}
sqlite3BeginBenignMalloc();
rc = echoTransactionCall(tab, "xCommit");
sqlite3EndBenignMalloc();
pVtab->inTransaction = 0;
return rc;
}
/*
** This function is used to resize the hash table used by the cache passed
** as the first argument.
**
** The global mutex must be held when this function is called.
*/
static int pcache1ResizeHash(PCache1 *p){
PgHdr1 **apNew;
unsigned int nNew;
unsigned int i;
assert( sqlite3_mutex_held(pcache1.mutex) );
nNew = p->nHash*2;
if( nNew<256 ){
nNew = 256;
}
pcache1LeaveMutex();
if( p->nHash ){ sqlite3BeginBenignMalloc(); }
apNew = (PgHdr1 **)sqlite3_malloc(sizeof(PgHdr1 *)*nNew);
if( p->nHash ){ sqlite3EndBenignMalloc(); }
pcache1EnterMutex();
if( apNew ){
memset(apNew, 0, sizeof(PgHdr1 *)*nNew);
for(i=0; i<p->nHash; i++){
PgHdr1 *pPage;
PgHdr1 *pNext = p->apHash[i];
while( (pPage = pNext)!=0 ){
unsigned int h = pPage->iKey % nNew;
pNext = pPage->pNext;
pPage->pNext = apNew[h];
apNew[h] = pPage;
}
}
sqlite3_free(p->apHash);
p->apHash = apNew;
p->nHash = nNew;
}
return (p->apHash ? SQLITE_OK : SQLITE_NOMEM);
}
/*
** Set the i-th bit. Return 0 on success and an error code if
** anything goes wrong.
**
** This routine might cause sub-bitmaps to be allocated. Failing
** to get the memory needed to hold the sub-bitmap is the only
** that can go wrong with an insert, assuming p and i are valid.
**
** The calling function must ensure that p is a valid Bitvec object
** and that the value for "i" is within range of the Bitvec object.
** Otherwise the behavior is undefined.
*/
int sqlite3BitvecSet(Bitvec *p, u32 i){
u32 h;
assert( p!=0 );
assert( i>0 );
assert( i<=p->iSize );
i--;
while((p->iSize > BITVEC_NBIT) && p->iDivisor) {
u32 bin = i/p->iDivisor;
i = i%p->iDivisor;
if( p->u.apSub[bin]==0 ){
sqlite3BeginBenignMalloc();
p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );
sqlite3EndBenignMalloc();
if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM;
}
p = p->u.apSub[bin];
}
if( p->iSize<=BITVEC_NBIT ){
p->u.aBitmap[i/BITVEC_SZELEM] |= 1 << (i&(BITVEC_SZELEM-1));
return SQLITE_OK;
}
h = BITVEC_HASH(i++);
/* if there wasn't a hash collision, and this doesn't */
/* completely fill the hash, then just add it without */
/* worring about sub-dividing and re-hashing. */
if( !p->u.aHash[h] ){
if (p->nSet<(BITVEC_NINT-1)) {
goto bitvec_set_end;
} else {
goto bitvec_set_rehash;
}
}
/* there was a collision, check to see if it's already */
/* in hash, if not, try to find a spot for it */
do {
if( p->u.aHash[h]==i ) return SQLITE_OK;
h++;
if( h>=BITVEC_NINT ) h = 0;
} while( p->u.aHash[h] );
/* we didn't find it in the hash. h points to the first */
/* available free spot. check to see if this is going to */
/* make our hash too "full". */
bitvec_set_rehash:
if( p->nSet>=BITVEC_MXHASH ){
unsigned int j;
int rc;
u32 aiValues[BITVEC_NINT];
memcpy(aiValues, p->u.aHash, sizeof(aiValues));
memset(p->u.apSub, 0, sizeof(aiValues));
p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;
rc = sqlite3BitvecSet(p, i);
for(j=0; j<BITVEC_NINT; j++){
if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);
}
return rc;
}
bitvec_set_end:
p->nSet++;
p->u.aHash[h] = i;
return SQLITE_OK;
}
/*
** This function is called when
** the transaction opened by database db has just finished. Locks held
** by database connection db have been released.
**
** This function loops through each entry in the blocked connections
** list and does the following:
**
** 1) If the sqlite3.pBlockingConnection member of a list entry is
** set to db, then set pBlockingConnection=0.
**
** 2) If the sqlite3.pUnlockConnection member of a list entry is
** set to db, then invoke the configured unlock-notify callback and
** set pUnlockConnection=0.
**
** 3) If the two steps above mean that pBlockingConnection==0 and
** pUnlockConnection==0, remove the entry from the blocked connections
** list.
*/
void sqlite3ConnectionUnlocked(sqlite3 *db){
void (*xUnlockNotify)(void **, int) = 0; /* Unlock-notify cb to invoke */
int nArg = 0; /* Number of entries in aArg[] */
sqlite3 **pp; /* Iterator variable */
void **aArg; /* Arguments to the unlock callback */
void **aDyn = 0; /* Dynamically allocated space for aArg[] */
void *aStatic[16]; /* Starter space for aArg[]. No malloc required */
aArg = aStatic;
enterMutex(); /* Enter STATIC_MASTER mutex */
/* This loop runs once for each entry in the blocked-connections list. */
for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){
sqlite3 *p = *pp;
/* Step 1. */
if( p->pBlockingConnection==db ){
p->pBlockingConnection = 0;
}
/* Step 2. */
if( p->pUnlockConnection==db ){
assert( p->xUnlockNotify );
if( p->xUnlockNotify!=xUnlockNotify && nArg!=0 ){
xUnlockNotify(aArg, nArg);
nArg = 0;
}
sqlite3BeginBenignMalloc();
assert( aArg==aDyn || (aDyn==0 && aArg==aStatic) );
assert( nArg<=(int)ArraySize(aStatic) || aArg==aDyn );
if( (!aDyn && nArg==(int)ArraySize(aStatic))
|| (aDyn && nArg==(int)(sqlite3MallocSize(aDyn)/sizeof(void*)))
){
/* The aArg[] array needs to grow. */
void **pNew = (void **)sqlite3Malloc(nArg*sizeof(void *)*2);
if( pNew ){
memcpy(pNew, aArg, nArg*sizeof(void *));
sqlite3_free(aDyn);
aDyn = aArg = pNew;
}else{
/* This occurs when the array of context pointers that need to
** be passed to the unlock-notify callback is larger than the
** aStatic[] array allocated on the stack and the attempt to
** allocate a larger array from the heap has failed.
**
** This is a difficult situation to handle. Returning an error
** code to the caller is insufficient, as even if an error code
** is returned the transaction on connection db will still be
** closed and the unlock-notify callbacks on blocked connections
** will go unissued. This might cause the application to wait
** indefinitely for an unlock-notify callback that will never
** arrive.
**
** Instead, invoke the unlock-notify callback with the context
** array already accumulated. We can then clear the array and
** begin accumulating any further context pointers without
** requiring any dynamic allocation. This is sub-optimal because
** it means that instead of one callback with a large array of
** context pointers the application will receive two or more
** callbacks with smaller arrays of context pointers, which will
** reduce the applications ability to prioritize multiple
** connections. But it is the best that can be done under the
** circumstances.
*/
xUnlockNotify(aArg, nArg);
nArg = 0;
}
}
sqlite3EndBenignMalloc();
aArg[nArg++] = p->pUnlockArg;
xUnlockNotify = p->xUnlockNotify;
p->pUnlockConnection = 0;
p->xUnlockNotify = 0;
p->pUnlockArg = 0;
}
/* Step 3. */
if( p->pBlockingConnection==0 && p->pUnlockConnection==0 ){
/* Remove connection p from the blocked connections list. */
*pp = p->pNextBlocked;
p->pNextBlocked = 0;
}else{
pp = &p->pNextBlocked;
}
}
if( nArg!=0 ){
xUnlockNotify(aArg, nArg);
}
sqlite3_free(aDyn);
leaveMutex(); /* Leave STATIC_MASTER mutex */
}
/*
** Implementation of the sqlite3_pcache.xFetch method.
**
** Fetch a page by key value.
**
** Whether or not a new page may be allocated by this function depends on
** the value of the createFlag argument.
**
** There are three different approaches to obtaining space for a page,
** depending on the value of parameter createFlag (which may be 0, 1 or 2).
**
** 1. Regardless of the value of createFlag, the cache is searched for a
** copy of the requested page. If one is found, it is returned.
**
** 2. If createFlag==0 and the page is not already in the cache, NULL is
** returned.
**
** 3. If createFlag is 1, the cache is marked as purgeable and the page is
** not already in the cache, and if either of the following are true,
** return NULL:
**
** (a) the number of pages pinned by the cache is greater than
** PCache1.nMax, or
** (b) the number of pages pinned by the cache is greater than
** the sum of nMax for all purgeable caches, less the sum of
** nMin for all other purgeable caches.
**
** 4. If none of the first three conditions apply and the cache is marked
** as purgeable, and if one of the following is true:
**
** (a) The number of pages allocated for the cache is already
** PCache1.nMax, or
**
** (b) The number of pages allocated for all purgeable caches is
** already equal to or greater than the sum of nMax for all
** purgeable caches,
**
** then attempt to recycle a page from the LRU list. If it is the right
** size, return the recycled buffer. Otherwise, free the buffer and
** proceed to step 5.
**
** 5. Otherwise, allocate and return a new page buffer.
*/
static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){
unsigned int nPinned;
PCache1 *pCache = (PCache1 *)p;
PgHdr1 *pPage = 0;
pcache1EnterMutex();
if( createFlag==1 ) sqlite3BeginBenignMalloc();
/* Search the hash table for an existing entry. */
if( pCache->nHash>0 ){
unsigned int h = iKey % pCache->nHash;
for(pPage=pCache->apHash[h]; pPage&&pPage->iKey!=iKey; pPage=pPage->pNext);
}
if( pPage || createFlag==0 ){
pcache1PinPage(pPage);
goto fetch_out;
}
/* Step 3 of header comment. */
nPinned = pCache->nPage - pCache->nRecyclable;
if( createFlag==1 && pCache->bPurgeable && (
nPinned>=(pcache1.nMaxPage+pCache->nMin-pcache1.nMinPage)
|| nPinned>=(pCache->nMax)
)){
goto fetch_out;
}
if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){
goto fetch_out;
}
/* Step 4. Try to recycle a page buffer if appropriate. */
if( pCache->bPurgeable && pcache1.pLruTail && (
pCache->nPage>=pCache->nMax-1 || pcache1.nCurrentPage>=pcache1.nMaxPage
)){
pPage = pcache1.pLruTail;
pcache1RemoveFromHash(pPage);
pcache1PinPage(pPage);
if( pPage->pCache->szPage!=pCache->szPage ){
pcache1FreePage(pPage);
pPage = 0;
}else{
pcache1.nCurrentPage -= (pPage->pCache->bPurgeable - pCache->bPurgeable);
}
}
/* Step 5. If a usable page buffer has still not been found,
** attempt to allocate a new one.
*/
if( !pPage ){
pPage = pcache1AllocPage(pCache);
}
if( pPage ){
unsigned int h = iKey % pCache->nHash;
*(void **)(PGHDR1_TO_PAGE(pPage)) = 0;
pCache->nPage++;
pPage->iKey = iKey;
pPage->pNext = pCache->apHash[h];
pPage->pCache = pCache;
pPage->pLruPrev = 0;
pPage->pLruNext = 0;
pCache->apHash[h] = pPage;
}
fetch_out:
if( pPage && iKey>pCache->iMaxKey ){
pCache->iMaxKey = iKey;
}
if( createFlag==1 ) sqlite3EndBenignMalloc();
pcache1LeaveMutex();
return (pPage ? PGHDR1_TO_PAGE(pPage) : 0);
}
