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-rw-r--r--src/pcache.c105
1 files changed, 65 insertions, 40 deletions
diff --git a/src/pcache.c b/src/pcache.c
index f37511e..482a188 100644
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -20,7 +20,7 @@ struct PCache {
PgHdr *pDirty, *pDirtyTail; /* List of dirty pages in LRU order */
PgHdr *pSynced; /* Last synced page in dirty page list */
int nRef; /* Number of referenced pages */
- int nMax; /* Configured cache size */
+ int szCache; /* Configured cache size */
int szPage; /* Size of every page in this cache */
int szExtra; /* Size of extra space for each page */
int bPurgeable; /* True if pages are on backing store */
@@ -131,7 +131,7 @@ static void pcacheUnpin(PgHdr *p){
if( p->pgno==1 ){
pCache->pPage1 = 0;
}
- sqlite3GlobalConfig.pcache.xUnpin(pCache->pCache, p, 0);
+ sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 0);
}
}
@@ -141,18 +141,18 @@ static void pcacheUnpin(PgHdr *p){
** functions are threadsafe.
*/
int sqlite3PcacheInitialize(void){
- if( sqlite3GlobalConfig.pcache.xInit==0 ){
+ if( sqlite3GlobalConfig.pcache2.xInit==0 ){
/* IMPLEMENTATION-OF: R-26801-64137 If the xInit() method is NULL, then the
** built-in default page cache is used instead of the application defined
** page cache. */
sqlite3PCacheSetDefault();
}
- return sqlite3GlobalConfig.pcache.xInit(sqlite3GlobalConfig.pcache.pArg);
+ return sqlite3GlobalConfig.pcache2.xInit(sqlite3GlobalConfig.pcache2.pArg);
}
void sqlite3PcacheShutdown(void){
- if( sqlite3GlobalConfig.pcache.xShutdown ){
+ if( sqlite3GlobalConfig.pcache2.xShutdown ){
/* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */
- sqlite3GlobalConfig.pcache.xShutdown(sqlite3GlobalConfig.pcache.pArg);
+ sqlite3GlobalConfig.pcache2.xShutdown(sqlite3GlobalConfig.pcache2.pArg);
}
}
@@ -181,7 +181,7 @@ void sqlite3PcacheOpen(
p->bPurgeable = bPurgeable;
p->xStress = xStress;
p->pStress = pStress;
- p->nMax = 100;
+ p->szCache = 100;
}
/*
@@ -191,7 +191,7 @@ void sqlite3PcacheOpen(
void sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
assert( pCache->nRef==0 && pCache->pDirty==0 );
if( pCache->pCache ){
- sqlite3GlobalConfig.pcache.xDestroy(pCache->pCache);
+ sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
pCache->pCache = 0;
pCache->pPage1 = 0;
}
@@ -199,6 +199,17 @@ void sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
}
/*
+** Compute the number of pages of cache requested.
+*/
+static int numberOfCachePages(PCache *p){
+ if( p->szCache>=0 ){
+ return p->szCache;
+ }else{
+ return (int)((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));
+ }
+}
+
+/*
** Try to obtain a page from the cache.
*/
int sqlite3PcacheFetch(
@@ -207,7 +218,8 @@ int sqlite3PcacheFetch(
int createFlag, /* If true, create page if it does not exist already */
PgHdr **ppPage /* Write the page here */
){
- PgHdr *pPage = 0;
+ sqlite3_pcache_page *pPage = 0;
+ PgHdr *pPgHdr = 0;
int eCreate;
assert( pCache!=0 );
@@ -219,19 +231,19 @@ int sqlite3PcacheFetch(
*/
if( !pCache->pCache && createFlag ){
sqlite3_pcache *p;
- int nByte;
- nByte = pCache->szPage + pCache->szExtra + sizeof(PgHdr);
- p = sqlite3GlobalConfig.pcache.xCreate(nByte, pCache->bPurgeable);
+ p = sqlite3GlobalConfig.pcache2.xCreate(
+ pCache->szPage, pCache->szExtra + sizeof(PgHdr), pCache->bPurgeable
+ );
if( !p ){
return SQLITE_NOMEM;
}
- sqlite3GlobalConfig.pcache.xCachesize(p, pCache->nMax);
+ sqlite3GlobalConfig.pcache2.xCachesize(p, numberOfCachePages(pCache));
pCache->pCache = p;
}
eCreate = createFlag * (1 + (!pCache->bPurgeable || !pCache->pDirty));
if( pCache->pCache ){
- pPage = sqlite3GlobalConfig.pcache.xFetch(pCache->pCache, pgno, eCreate);
+ pPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);
}
if( !pPage && eCreate==1 ){
@@ -258,7 +270,7 @@ int sqlite3PcacheFetch(
"spill page %d making room for %d - cache used: %d/%d",
pPg->pgno, pgno,
sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
- pCache->nMax);
+ numberOfCachePages(pCache));
#endif
rc = pCache->xStress(pCache->pStress, pPg);
if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
@@ -266,33 +278,36 @@ int sqlite3PcacheFetch(
}
}
- pPage = sqlite3GlobalConfig.pcache.xFetch(pCache->pCache, pgno, 2);
+ pPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2);
}
if( pPage ){
- if( !pPage->pData ){
- memset(pPage, 0, sizeof(PgHdr));
- pPage->pData = (void *)&pPage[1];
- pPage->pExtra = (void*)&((char *)pPage->pData)[pCache->szPage];
- memset(pPage->pExtra, 0, pCache->szExtra);
- pPage->pCache = pCache;
- pPage->pgno = pgno;
+ pPgHdr = (PgHdr *)pPage->pExtra;
+
+ if( !pPgHdr->pPage ){
+ memset(pPgHdr, 0, sizeof(PgHdr));
+ pPgHdr->pPage = pPage;
+ pPgHdr->pData = pPage->pBuf;
+ pPgHdr->pExtra = (void *)&pPgHdr[1];
+ memset(pPgHdr->pExtra, 0, pCache->szExtra);
+ pPgHdr->pCache = pCache;
+ pPgHdr->pgno = pgno;
}
- assert( pPage->pCache==pCache );
- assert( pPage->pgno==pgno );
- assert( pPage->pData==(void *)&pPage[1] );
- assert( pPage->pExtra==(void *)&((char *)&pPage[1])[pCache->szPage] );
+ assert( pPgHdr->pCache==pCache );
+ assert( pPgHdr->pgno==pgno );
+ assert( pPgHdr->pData==pPage->pBuf );
+ assert( pPgHdr->pExtra==(void *)&pPgHdr[1] );
- if( 0==pPage->nRef ){
+ if( 0==pPgHdr->nRef ){
pCache->nRef++;
}
- pPage->nRef++;
+ pPgHdr->nRef++;
if( pgno==1 ){
- pCache->pPage1 = pPage;
+ pCache->pPage1 = pPgHdr;
}
}
- *ppPage = pPage;
- return (pPage==0 && eCreate) ? SQLITE_NOMEM : SQLITE_OK;
+ *ppPage = pPgHdr;
+ return (pPgHdr==0 && eCreate) ? SQLITE_NOMEM : SQLITE_OK;
}
/*
@@ -339,7 +354,7 @@ void sqlite3PcacheDrop(PgHdr *p){
if( p->pgno==1 ){
pCache->pPage1 = 0;
}
- sqlite3GlobalConfig.pcache.xUnpin(pCache->pCache, p, 1);
+ sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 1);
}
/*
@@ -397,7 +412,7 @@ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
PCache *pCache = p->pCache;
assert( p->nRef>0 );
assert( newPgno>0 );
- sqlite3GlobalConfig.pcache.xRekey(pCache->pCache, p, p->pgno, newPgno);
+ sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);
p->pgno = newPgno;
if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){
pcacheRemoveFromDirtyList(p);
@@ -434,7 +449,7 @@ void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
memset(pCache->pPage1->pData, 0, pCache->szPage);
pgno = 1;
}
- sqlite3GlobalConfig.pcache.xTruncate(pCache->pCache, pgno+1);
+ sqlite3GlobalConfig.pcache2.xTruncate(pCache->pCache, pgno+1);
}
}
@@ -443,7 +458,7 @@ void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
*/
void sqlite3PcacheClose(PCache *pCache){
if( pCache->pCache ){
- sqlite3GlobalConfig.pcache.xDestroy(pCache->pCache);
+ sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);
}
}
@@ -555,7 +570,7 @@ int sqlite3PcachePageRefcount(PgHdr *p){
int sqlite3PcachePagecount(PCache *pCache){
int nPage = 0;
if( pCache->pCache ){
- nPage = sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache);
+ nPage = sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache);
}
return nPage;
}
@@ -565,7 +580,7 @@ int sqlite3PcachePagecount(PCache *pCache){
** Get the suggested cache-size value.
*/
int sqlite3PcacheGetCachesize(PCache *pCache){
- return pCache->nMax;
+ return numberOfCachePages(pCache);
}
#endif
@@ -573,9 +588,19 @@ int sqlite3PcacheGetCachesize(PCache *pCache){
** Set the suggested cache-size value.
*/
void sqlite3PcacheSetCachesize(PCache *pCache, int mxPage){
- pCache->nMax = mxPage;
+ pCache->szCache = mxPage;
+ if( pCache->pCache ){
+ sqlite3GlobalConfig.pcache2.xCachesize(pCache->pCache,
+ numberOfCachePages(pCache));
+ }
+}
+
+/*
+** Free up as much memory as possible from the page cache.
+*/
+void sqlite3PcacheShrink(PCache *pCache){
if( pCache->pCache ){
- sqlite3GlobalConfig.pcache.xCachesize(pCache->pCache, mxPage);
+ sqlite3GlobalConfig.pcache2.xShrink(pCache->pCache);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-20 08:30:35 +0000