diff options
| author | bernard <[email protected]> | 2017-11-02 13:50:42 +0800 |
|---|---|---|
| committer | bernard <[email protected]> | 2017-11-02 13:50:42 +0800 |
| commit | b2057f506a09e2adef81fc77efd697d16ae14bec (patch) | |
| tree | 3affefabfe376a0ec1b3ac4a5eef957c1dd58dc8 /components/external/SQLite-3.8.1/src/pcache.c | |
| parent | 23582c8129228b4961ad35319cfd2d270039345f (diff) | |
[External] Remove external from RT-Thread
Diffstat (limited to 'components/external/SQLite-3.8.1/src/pcache.c')
| -rw-r--r-- | components/external/SQLite-3.8.1/src/pcache.c | 619 |
1 files changed, 0 insertions, 619 deletions
diff --git a/components/external/SQLite-3.8.1/src/pcache.c b/components/external/SQLite-3.8.1/src/pcache.c deleted file mode 100644 index 482a188bee..0000000000 --- a/components/external/SQLite-3.8.1/src/pcache.c +++ /dev/null @@ -1,619 +0,0 @@ -/* -** 2008 August 05 -** -** 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. -** -************************************************************************* -** This file implements that page cache. -*/ -#include "sqliteInt.h" - -/* -** A complete page cache is an instance of this structure. -*/ -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 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 */ - int (*xStress)(void*,PgHdr*); /* Call to try make a page clean */ - void *pStress; /* Argument to xStress */ - sqlite3_pcache *pCache; /* Pluggable cache module */ - PgHdr *pPage1; /* Reference to page 1 */ -}; - -/* -** Some of the assert() macros in this code are too expensive to run -** even during normal debugging. Use them only rarely on long-running -** tests. Enable the expensive asserts using the -** -DSQLITE_ENABLE_EXPENSIVE_ASSERT=1 compile-time option. -*/ -#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT -# define expensive_assert(X) assert(X) -#else -# define expensive_assert(X) -#endif - -/********************************** Linked List Management ********************/ - -#if !defined(NDEBUG) && defined(SQLITE_ENABLE_EXPENSIVE_ASSERT) -/* -** Check that the pCache->pSynced variable is set correctly. If it -** is not, either fail an assert or return zero. Otherwise, return -** non-zero. This is only used in debugging builds, as follows: -** -** expensive_assert( pcacheCheckSynced(pCache) ); -*/ -static int pcacheCheckSynced(PCache *pCache){ - PgHdr *p; - for(p=pCache->pDirtyTail; p!=pCache->pSynced; p=p->pDirtyPrev){ - assert( p->nRef || (p->flags&PGHDR_NEED_SYNC) ); - } - return (p==0 || p->nRef || (p->flags&PGHDR_NEED_SYNC)==0); -} -#endif /* !NDEBUG && SQLITE_ENABLE_EXPENSIVE_ASSERT */ - -/* -** Remove page pPage from the list of dirty pages. -*/ -static void pcacheRemoveFromDirtyList(PgHdr *pPage){ - PCache *p = pPage->pCache; - - assert( pPage->pDirtyNext || pPage==p->pDirtyTail ); - assert( pPage->pDirtyPrev || pPage==p->pDirty ); - - /* Update the PCache1.pSynced variable if necessary. */ - if( p->pSynced==pPage ){ - PgHdr *pSynced = pPage->pDirtyPrev; - while( pSynced && (pSynced->flags&PGHDR_NEED_SYNC) ){ - pSynced = pSynced->pDirtyPrev; - } - p->pSynced = pSynced; - } - - if( pPage->pDirtyNext ){ - pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev; - }else{ - assert( pPage==p->pDirtyTail ); - p->pDirtyTail = pPage->pDirtyPrev; - } - if( pPage->pDirtyPrev ){ - pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext; - }else{ - assert( pPage==p->pDirty ); - p->pDirty = pPage->pDirtyNext; - } - pPage->pDirtyNext = 0; - pPage->pDirtyPrev = 0; - - expensive_assert( pcacheCheckSynced(p) ); -} - -/* -** Add page pPage to the head of the dirty list (PCache1.pDirty is set to -** pPage). -*/ -static void pcacheAddToDirtyList(PgHdr *pPage){ - PCache *p = pPage->pCache; - - assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage ); - - pPage->pDirtyNext = p->pDirty; - if( pPage->pDirtyNext ){ - assert( pPage->pDirtyNext->pDirtyPrev==0 ); - pPage->pDirtyNext->pDirtyPrev = pPage; - } - p->pDirty = pPage; - if( !p->pDirtyTail ){ - p->pDirtyTail = pPage; - } - if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){ - p->pSynced = pPage; - } - expensive_assert( pcacheCheckSynced(p) ); -} - -/* -** Wrapper around the pluggable caches xUnpin method. If the cache is -** being used for an in-memory database, this function is a no-op. -*/ -static void pcacheUnpin(PgHdr *p){ - PCache *pCache = p->pCache; - if( pCache->bPurgeable ){ - if( p->pgno==1 ){ - pCache->pPage1 = 0; - } - sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 0); - } -} - -/*************************************************** General Interfaces ****** -** -** Initialize and shutdown the page cache subsystem. Neither of these -** functions are threadsafe. -*/ -int sqlite3PcacheInitialize(void){ - 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.pcache2.xInit(sqlite3GlobalConfig.pcache2.pArg); -} -void sqlite3PcacheShutdown(void){ - if( sqlite3GlobalConfig.pcache2.xShutdown ){ - /* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */ - sqlite3GlobalConfig.pcache2.xShutdown(sqlite3GlobalConfig.pcache2.pArg); - } -} - -/* -** Return the size in bytes of a PCache object. -*/ -int sqlite3PcacheSize(void){ return sizeof(PCache); } - -/* -** Create a new PCache object. Storage space to hold the object -** has already been allocated and is passed in as the p pointer. -** The caller discovers how much space needs to be allocated by -** calling sqlite3PcacheSize(). -*/ -void sqlite3PcacheOpen( - int szPage, /* Size of every page */ - int szExtra, /* Extra space associated with each page */ - int bPurgeable, /* True if pages are on backing store */ - int (*xStress)(void*,PgHdr*),/* Call to try to make pages clean */ - void *pStress, /* Argument to xStress */ - PCache *p /* Preallocated space for the PCache */ -){ - memset(p, 0, sizeof(PCache)); - p->szPage = szPage; - p->szExtra = szExtra; - p->bPurgeable = bPurgeable; - p->xStress = xStress; - p->pStress = pStress; - p->szCache = 100; -} - -/* -** Change the page size for PCache object. The caller must ensure that there -** are no outstanding page references when this function is called. -*/ -void sqlite3PcacheSetPageSize(PCache *pCache, int szPage){ - assert( pCache->nRef==0 && pCache->pDirty==0 ); - if( pCache->pCache ){ - sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache); - pCache->pCache = 0; - pCache->pPage1 = 0; - } - pCache->szPage = 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( - PCache *pCache, /* Obtain the page from this cache */ - Pgno pgno, /* Page number to obtain */ - int createFlag, /* If true, create page if it does not exist already */ - PgHdr **ppPage /* Write the page here */ -){ - sqlite3_pcache_page *pPage = 0; - PgHdr *pPgHdr = 0; - int eCreate; - - assert( pCache!=0 ); - assert( createFlag==1 || createFlag==0 ); - assert( pgno>0 ); - - /* If the pluggable cache (sqlite3_pcache*) has not been allocated, - ** allocate it now. - */ - if( !pCache->pCache && createFlag ){ - sqlite3_pcache *p; - p = sqlite3GlobalConfig.pcache2.xCreate( - pCache->szPage, pCache->szExtra + sizeof(PgHdr), pCache->bPurgeable - ); - if( !p ){ - return SQLITE_NOMEM; - } - sqlite3GlobalConfig.pcache2.xCachesize(p, numberOfCachePages(pCache)); - pCache->pCache = p; - } - - eCreate = createFlag * (1 + (!pCache->bPurgeable || !pCache->pDirty)); - if( pCache->pCache ){ - pPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate); - } - - if( !pPage && eCreate==1 ){ - PgHdr *pPg; - - /* Find a dirty page to write-out and recycle. First try to find a - ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC - ** cleared), but if that is not possible settle for any other - ** unreferenced dirty page. - */ - expensive_assert( pcacheCheckSynced(pCache) ); - for(pPg=pCache->pSynced; - pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); - pPg=pPg->pDirtyPrev - ); - pCache->pSynced = pPg; - if( !pPg ){ - for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev); - } - if( pPg ){ - int rc; -#ifdef SQLITE_LOG_CACHE_SPILL - sqlite3_log(SQLITE_FULL, - "spill page %d making room for %d - cache used: %d/%d", - pPg->pgno, pgno, - sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache), - numberOfCachePages(pCache)); -#endif - rc = pCache->xStress(pCache->pStress, pPg); - if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){ - return rc; - } - } - - pPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2); - } - - if( pPage ){ - 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( pPgHdr->pCache==pCache ); - assert( pPgHdr->pgno==pgno ); - assert( pPgHdr->pData==pPage->pBuf ); - assert( pPgHdr->pExtra==(void *)&pPgHdr[1] ); - - if( 0==pPgHdr->nRef ){ - pCache->nRef++; - } - pPgHdr->nRef++; - if( pgno==1 ){ - pCache->pPage1 = pPgHdr; - } - } - *ppPage = pPgHdr; - return (pPgHdr==0 && eCreate) ? SQLITE_NOMEM : SQLITE_OK; -} - -/* -** Decrement the reference count on a page. If the page is clean and the -** reference count drops to 0, then it is made elible for recycling. -*/ -void sqlite3PcacheRelease(PgHdr *p){ - assert( p->nRef>0 ); - p->nRef--; - if( p->nRef==0 ){ - PCache *pCache = p->pCache; - pCache->nRef--; - if( (p->flags&PGHDR_DIRTY)==0 ){ - pcacheUnpin(p); - }else{ - /* Move the page to the head of the dirty list. */ - pcacheRemoveFromDirtyList(p); - pcacheAddToDirtyList(p); - } - } -} - -/* -** Increase the reference count of a supplied page by 1. -*/ -void sqlite3PcacheRef(PgHdr *p){ - assert(p->nRef>0); - p->nRef++; -} - -/* -** Drop a page from the cache. There must be exactly one reference to the -** page. This function deletes that reference, so after it returns the -** page pointed to by p is invalid. -*/ -void sqlite3PcacheDrop(PgHdr *p){ - PCache *pCache; - assert( p->nRef==1 ); - if( p->flags&PGHDR_DIRTY ){ - pcacheRemoveFromDirtyList(p); - } - pCache = p->pCache; - pCache->nRef--; - if( p->pgno==1 ){ - pCache->pPage1 = 0; - } - sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, p->pPage, 1); -} - -/* -** Make sure the page is marked as dirty. If it isn't dirty already, -** make it so. -*/ -void sqlite3PcacheMakeDirty(PgHdr *p){ - p->flags &= ~PGHDR_DONT_WRITE; - assert( p->nRef>0 ); - if( 0==(p->flags & PGHDR_DIRTY) ){ - p->flags |= PGHDR_DIRTY; - pcacheAddToDirtyList( p); - } -} - -/* -** Make sure the page is marked as clean. If it isn't clean already, -** make it so. -*/ -void sqlite3PcacheMakeClean(PgHdr *p){ - if( (p->flags & PGHDR_DIRTY) ){ - pcacheRemoveFromDirtyList(p); - p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC); - if( p->nRef==0 ){ - pcacheUnpin(p); - } - } -} - -/* -** Make every page in the cache clean. -*/ -void sqlite3PcacheCleanAll(PCache *pCache){ - PgHdr *p; - while( (p = pCache->pDirty)!=0 ){ - sqlite3PcacheMakeClean(p); - } -} - -/* -** Clear the PGHDR_NEED_SYNC flag from all dirty pages. -*/ -void sqlite3PcacheClearSyncFlags(PCache *pCache){ - PgHdr *p; - for(p=pCache->pDirty; p; p=p->pDirtyNext){ - p->flags &= ~PGHDR_NEED_SYNC; - } - pCache->pSynced = pCache->pDirtyTail; -} - -/* -** Change the page number of page p to newPgno. -*/ -void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){ - PCache *pCache = p->pCache; - assert( p->nRef>0 ); - assert( newPgno>0 ); - 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); - pcacheAddToDirtyList(p); - } -} - -/* -** Drop every cache entry whose page number is greater than "pgno". The -** caller must ensure that there are no outstanding references to any pages -** other than page 1 with a page number greater than pgno. -** -** If there is a reference to page 1 and the pgno parameter passed to this -** function is 0, then the data area associated with page 1 is zeroed, but -** the page object is not dropped. -*/ -void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){ - if( pCache->pCache ){ - PgHdr *p; - PgHdr *pNext; - for(p=pCache->pDirty; p; p=pNext){ - pNext = p->pDirtyNext; - /* This routine never gets call with a positive pgno except right - ** after sqlite3PcacheCleanAll(). So if there are dirty pages, - ** it must be that pgno==0. - */ - assert( p->pgno>0 ); - if( ALWAYS(p->pgno>pgno) ){ - assert( p->flags&PGHDR_DIRTY ); - sqlite3PcacheMakeClean(p); - } - } - if( pgno==0 && pCache->pPage1 ){ - memset(pCache->pPage1->pData, 0, pCache->szPage); - pgno = 1; - } - sqlite3GlobalConfig.pcache2.xTruncate(pCache->pCache, pgno+1); - } -} - -/* -** Close a cache. -*/ -void sqlite3PcacheClose(PCache *pCache){ - if( pCache->pCache ){ - sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache); - } -} - -/* -** Discard the contents of the cache. -*/ -void sqlite3PcacheClear(PCache *pCache){ - sqlite3PcacheTruncate(pCache, 0); -} - -/* -** Merge two lists of pages connected by pDirty and in pgno order. -** Do not both fixing the pDirtyPrev pointers. -*/ -static PgHdr *pcacheMergeDirtyList(PgHdr *pA, PgHdr *pB){ - PgHdr result, *pTail; - pTail = &result; - while( pA && pB ){ - if( pA->pgno<pB->pgno ){ - pTail->pDirty = pA; - pTail = pA; - pA = pA->pDirty; - }else{ - pTail->pDirty = pB; - pTail = pB; - pB = pB->pDirty; - } - } - if( pA ){ - pTail->pDirty = pA; - }else if( pB ){ - pTail->pDirty = pB; - }else{ - pTail->pDirty = 0; - } - return result.pDirty; -} - -/* -** Sort the list of pages in accending order by pgno. Pages are -** connected by pDirty pointers. The pDirtyPrev pointers are -** corrupted by this sort. -** -** Since there cannot be more than 2^31 distinct pages in a database, -** there cannot be more than 31 buckets required by the merge sorter. -** One extra bucket is added to catch overflow in case something -** ever changes to make the previous sentence incorrect. -*/ -#define N_SORT_BUCKET 32 -static PgHdr *pcacheSortDirtyList(PgHdr *pIn){ - PgHdr *a[N_SORT_BUCKET], *p; - int i; - memset(a, 0, sizeof(a)); - while( pIn ){ - p = pIn; - pIn = p->pDirty; - p->pDirty = 0; - for(i=0; ALWAYS(i<N_SORT_BUCKET-1); i++){ - if( a[i]==0 ){ - a[i] = p; - break; - }else{ - p = pcacheMergeDirtyList(a[i], p); - a[i] = 0; - } - } - if( NEVER(i==N_SORT_BUCKET-1) ){ - /* To get here, there need to be 2^(N_SORT_BUCKET) elements in - ** the input list. But that is impossible. - */ - a[i] = pcacheMergeDirtyList(a[i], p); - } - } - p = a[0]; - for(i=1; i<N_SORT_BUCKET; i++){ - p = pcacheMergeDirtyList(p, a[i]); - } - return p; -} - -/* -** Return a list of all dirty pages in the cache, sorted by page number. -*/ -PgHdr *sqlite3PcacheDirtyList(PCache *pCache){ - PgHdr *p; - for(p=pCache->pDirty; p; p=p->pDirtyNext){ - p->pDirty = p->pDirtyNext; - } - return pcacheSortDirtyList(pCache->pDirty); -} - -/* -** Return the total number of referenced pages held by the cache. -*/ -int sqlite3PcacheRefCount(PCache *pCache){ - return pCache->nRef; -} - -/* -** Return the number of references to the page supplied as an argument. -*/ -int sqlite3PcachePageRefcount(PgHdr *p){ - return p->nRef; -} - -/* -** Return the total number of pages in the cache. -*/ -int sqlite3PcachePagecount(PCache *pCache){ - int nPage = 0; - if( pCache->pCache ){ - nPage = sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache); - } - return nPage; -} - -#ifdef SQLITE_TEST -/* -** Get the suggested cache-size value. -*/ -int sqlite3PcacheGetCachesize(PCache *pCache){ - return numberOfCachePages(pCache); -} -#endif - -/* -** Set the suggested cache-size value. -*/ -void sqlite3PcacheSetCachesize(PCache *pCache, int 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.pcache2.xShrink(pCache->pCache); - } -} - -#if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG) -/* -** For all dirty pages currently in the cache, invoke the specified -** callback. This is only used if the SQLITE_CHECK_PAGES macro is -** defined. -*/ -void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *)){ - PgHdr *pDirty; - for(pDirty=pCache->pDirty; pDirty; pDirty=pDirty->pDirtyNext){ - xIter(pDirty); - } -} -#endif |
