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authorbernard <[email protected]>2017-11-02 13:50:42 +0800
committerbernard <[email protected]>2017-11-02 13:50:42 +0800
commitb2057f506a09e2adef81fc77efd697d16ae14bec (patch)
tree3affefabfe376a0ec1b3ac4a5eef957c1dd58dc8 /components/external/SQLite-3.8.1/src/pcache.c
parent23582c8129228b4961ad35319cfd2d270039345f (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.c619
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