diff --git a/manifest b/manifest index 1044726bb0..6e1bca5a72 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Faster\simplementation\sof\sthe\ssqlite3ApiExit()\sroutine. -D 2014-08-23T20:25:53.209 +C Faster\simplementation\sof\spcache1Fetch() +D 2014-08-23T23:15:31.233 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23 @@ -216,7 +216,7 @@ F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428 F src/parse.y 22d6a074e5f5a7258947a1dc55a9bf946b765dd0 F src/pcache.c da602c5447051705cab41604bf3276815eb569d0 F src/pcache.h a5e4f5d9f5d592051d91212c5949517971ae6222 -F src/pcache1.c 102e6f5a2fbc646154463eb856d1fd716867b64c +F src/pcache1.c c5af6403a55178c9d1c09e4f77b0f9c88822762c F src/pragma.c d10ef67c4de79f78188b965b4b7988aff1d66f2e F src/prepare.c 3842c1dfc0b053458e3adcf9f6efc48e03e3fe3d F src/printf.c 00986c86ddfffefc2fd3c73667ff51b3b9709c74 @@ -1188,7 +1188,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f -P 6da6f46d0c43e3b68c21f514ddf8ee663c20f249 -R cfcb5b6ff857caed22b759c12472ea06 +P bd41d394d48516eb7d8ddc46abdcb427aa80173e +R d2491d65f44f8709d1d156c840c25703 U drh -Z c1d7ee14996f329ac13456e7bf7bb3df +Z 15bb2365f5f8da3e5de34ee820ad0674 diff --git a/manifest.uuid b/manifest.uuid index 215297c16b..bd2aebab20 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -bd41d394d48516eb7d8ddc46abdcb427aa80173e \ No newline at end of file +0371cc3bb07448bcd64fd671f3e71bb7f30deb4d \ No newline at end of file diff --git a/src/pcache1.c b/src/pcache1.c index 1644b0693c..82015befce 100644 --- a/src/pcache1.c +++ b/src/pcache1.c @@ -383,7 +383,7 @@ static int pcache1UnderMemoryPressure(PCache1 *pCache){ ** ** The PCache mutex must be held when this function is called. */ -static int pcache1ResizeHash(PCache1 *p){ +static void pcache1ResizeHash(PCache1 *p){ PgHdr1 **apNew; unsigned int nNew; unsigned int i; @@ -415,8 +415,6 @@ static int pcache1ResizeHash(PCache1 *p){ p->apHash = apNew; p->nHash = nNew; } - - return (p->apHash ? SQLITE_OK : SQLITE_NOMEM); } /* @@ -551,6 +549,9 @@ static void pcache1Shutdown(void *NotUsed){ memset(&pcache1, 0, sizeof(pcache1)); } +/* forward declaration */ +static void pcache1Destroy(sqlite3_pcache *p); + /* ** Implementation of the sqlite3_pcache.xCreate method. ** @@ -595,12 +596,17 @@ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){ pCache->szPage = szPage; pCache->szExtra = szExtra; pCache->bPurgeable = (bPurgeable ? 1 : 0); + pcache1EnterMutex(pGroup); + pcache1ResizeHash(pCache); if( bPurgeable ){ pCache->nMin = 10; - pcache1EnterMutex(pGroup); pGroup->nMinPage += pCache->nMin; pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage; - pcache1LeaveMutex(pGroup); + } + pcache1LeaveMutex(pGroup); + if( pCache->nHash==0 ){ + pcache1Destroy((sqlite3_pcache*)pCache); + pCache = 0; } } return (sqlite3_pcache *)pCache; @@ -656,6 +662,95 @@ static int pcache1Pagecount(sqlite3_pcache *p){ return n; } + +/* +** Implement steps 3, 4, and 5 of the pcache1Fetch() algorithm described +** in the header of the pcache1Fetch() procedure. +** +** This steps are broken out into a separate procedure because they are +** usually not needed, and by avoiding the stack initialization required +** for these steps, the main pcache1Fetch() procedure can run faster. +*/ +static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2( + PCache1 *pCache, + unsigned int iKey, + int createFlag +){ + unsigned int nPinned; + PGroup *pGroup = pCache->pGroup; + PgHdr1 *pPage = 0; + + /* Step 3: Abort if createFlag is 1 but the cache is nearly full */ + assert( pCache->nPage >= pCache->nRecyclable ); + nPinned = pCache->nPage - pCache->nRecyclable; + assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage ); + assert( pCache->n90pct == pCache->nMax*9/10 ); + if( createFlag==1 && ( + nPinned>=pGroup->mxPinned + || nPinned>=pCache->n90pct + || pcache1UnderMemoryPressure(pCache) + )){ + return 0; + } + + if( pCache->nPage>=pCache->nHash ) pcache1ResizeHash(pCache); + assert( pCache->nHash>0 && pCache->apHash ); + + /* Step 4. Try to recycle a page. */ + if( pCache->bPurgeable && pGroup->pLruTail && ( + (pCache->nPage+1>=pCache->nMax) + || pGroup->nCurrentPage>=pGroup->nMaxPage + || pcache1UnderMemoryPressure(pCache) + )){ + PCache1 *pOther; + pPage = pGroup->pLruTail; + assert( pPage->isPinned==0 ); + pcache1RemoveFromHash(pPage); + pcache1PinPage(pPage); + pOther = pPage->pCache; + + /* We want to verify that szPage and szExtra are the same for pOther + ** and pCache. Assert that we can verify this by comparing sums. */ + assert( (pCache->szPage & (pCache->szPage-1))==0 && pCache->szPage>=512 ); + assert( pCache->szExtra<512 ); + assert( (pOther->szPage & (pOther->szPage-1))==0 && pOther->szPage>=512 ); + assert( pOther->szExtra<512 ); + + if( pOther->szPage+pOther->szExtra != pCache->szPage+pCache->szExtra ){ + pcache1FreePage(pPage); + pPage = 0; + }else{ + pGroup->nCurrentPage -= (pOther->bPurgeable - pCache->bPurgeable); + } + } + + /* Step 5. If a usable page buffer has still not been found, + ** attempt to allocate a new one. + */ + if( !pPage ){ + if( createFlag==1 ) sqlite3BeginBenignMalloc(); + pPage = pcache1AllocPage(pCache); + if( createFlag==1 ) sqlite3EndBenignMalloc(); + } + + if( pPage ){ + unsigned int h = iKey % pCache->nHash; + pCache->nPage++; + pPage->iKey = iKey; + pPage->pNext = pCache->apHash[h]; + pPage->pCache = pCache; + pPage->pLruPrev = 0; + pPage->pLruNext = 0; + pPage->isPinned = 1; + *(void **)pPage->page.pExtra = 0; + pCache->apHash[h] = pPage; + if( iKey>pCache->iMaxKey ){ + pCache->iMaxKey = iKey; + } + } + return pPage; +} + /* ** Implementation of the sqlite3_pcache.xFetch method. ** @@ -715,9 +810,7 @@ static sqlite3_pcache_page *pcache1Fetch( unsigned int iKey, int createFlag ){ - unsigned int nPinned; PCache1 *pCache = (PCache1 *)p; - PGroup *pGroup; PgHdr1 *pPage = 0; assert( offsetof(PgHdr1,page)==0 ); @@ -725,107 +818,22 @@ static sqlite3_pcache_page *pcache1Fetch( assert( pCache->bPurgeable || pCache->nMin==0 ); assert( pCache->bPurgeable==0 || pCache->nMin==10 ); assert( pCache->nMin==0 || pCache->bPurgeable ); - pcache1EnterMutex(pGroup = pCache->pGroup); + assert( pCache->nHash>0 ); + pcache1EnterMutex(pCache->pGroup); /* Step 1: 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); - } + pPage = pCache->apHash[iKey % pCache->nHash]; + while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; } /* Step 2: Abort if no existing page is found and createFlag is 0 */ if( pPage ){ if( !pPage->isPinned ) pcache1PinPage(pPage); - goto fetch_out; + }else if( createFlag ){ + /* Steps 3, 4, and 5 implemented by this subroutine */ + pPage = pcache1FetchStage2(pCache, iKey, createFlag); } - if( createFlag==0 ){ - goto fetch_out; - } - - /* The pGroup local variable will normally be initialized by the - ** pcache1EnterMutex() macro above. But if SQLITE_MUTEX_OMIT is defined, - ** then pcache1EnterMutex() is a no-op, so we have to initialize the - ** local variable here. Delaying the initialization of pGroup is an - ** optimization: The common case is to exit the module before reaching - ** this point. - */ -#ifdef SQLITE_MUTEX_OMIT - pGroup = pCache->pGroup; -#endif - - /* Step 3: Abort if createFlag is 1 but the cache is nearly full */ - assert( pCache->nPage >= pCache->nRecyclable ); - nPinned = pCache->nPage - pCache->nRecyclable; - assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage ); - assert( pCache->n90pct == pCache->nMax*9/10 ); - if( createFlag==1 && ( - nPinned>=pGroup->mxPinned - || nPinned>=pCache->n90pct - || pcache1UnderMemoryPressure(pCache) - )){ - goto fetch_out; - } - - if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){ - goto fetch_out; - } - assert( pCache->nHash>0 && pCache->apHash ); - - /* Step 4. Try to recycle a page. */ - if( pCache->bPurgeable && pGroup->pLruTail && ( - (pCache->nPage+1>=pCache->nMax) - || pGroup->nCurrentPage>=pGroup->nMaxPage - || pcache1UnderMemoryPressure(pCache) - )){ - PCache1 *pOther; - pPage = pGroup->pLruTail; - assert( pPage->isPinned==0 ); - pcache1RemoveFromHash(pPage); - pcache1PinPage(pPage); - pOther = pPage->pCache; - - /* We want to verify that szPage and szExtra are the same for pOther - ** and pCache. Assert that we can verify this by comparing sums. */ - assert( (pCache->szPage & (pCache->szPage-1))==0 && pCache->szPage>=512 ); - assert( pCache->szExtra<512 ); - assert( (pOther->szPage & (pOther->szPage-1))==0 && pOther->szPage>=512 ); - assert( pOther->szExtra<512 ); - - if( pOther->szPage+pOther->szExtra != pCache->szPage+pCache->szExtra ){ - pcache1FreePage(pPage); - pPage = 0; - }else{ - pGroup->nCurrentPage -= (pOther->bPurgeable - pCache->bPurgeable); - } - } - - /* Step 5. If a usable page buffer has still not been found, - ** attempt to allocate a new one. - */ - if( !pPage ){ - if( createFlag==1 ) sqlite3BeginBenignMalloc(); - pPage = pcache1AllocPage(pCache); - if( createFlag==1 ) sqlite3EndBenignMalloc(); - } - - if( pPage ){ - unsigned int h = iKey % pCache->nHash; - pCache->nPage++; - pPage->iKey = iKey; - pPage->pNext = pCache->apHash[h]; - pPage->pCache = pCache; - pPage->pLruPrev = 0; - pPage->pLruNext = 0; - pPage->isPinned = 1; - *(void **)pPage->page.pExtra = 0; - pCache->apHash[h] = pPage; - } - -fetch_out: - if( pPage && iKey>pCache->iMaxKey ){ - pCache->iMaxKey = iKey; - } - pcache1LeaveMutex(pGroup); + assert( pPage==0 || pCache->iMaxKey>=iKey ); + pcache1LeaveMutex(pCache->pGroup); return (sqlite3_pcache_page*)pPage; }