Index: third_party/sqlite/sqlite-src-3080704/src/pcache.c |
diff --git a/third_party/sqlite/sqlite-src-3080704/src/pcache.c b/third_party/sqlite/sqlite-src-3080704/src/pcache.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..191a9d00f41ded328642e71fa5da12138f38bc35 |
--- /dev/null |
+++ b/third_party/sqlite/sqlite-src-3080704/src/pcache.c |
@@ -0,0 +1,666 @@ |
+/* |
+** 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 */ |
+ u8 bPurgeable; /* True if pages are on backing store */ |
+ u8 eCreate; /* eCreate value for for xFetch() */ |
+ 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 ********************/ |
+ |
+/* Allowed values for second argument to pcacheManageDirtyList() */ |
+#define PCACHE_DIRTYLIST_REMOVE 1 /* Remove pPage from dirty list */ |
+#define PCACHE_DIRTYLIST_ADD 2 /* Add pPage to the dirty list */ |
+#define PCACHE_DIRTYLIST_FRONT 3 /* Move pPage to the front of the list */ |
+ |
+/* |
+** Manage pPage's participation on the dirty list. Bits of the addRemove |
+** argument determines what operation to do. The 0x01 bit means first |
+** remove pPage from the dirty list. The 0x02 means add pPage back to |
+** the dirty list. Doing both moves pPage to the front of the dirty list. |
+*/ |
+static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){ |
+ PCache *p = pPage->pCache; |
+ |
+ if( addRemove & PCACHE_DIRTYLIST_REMOVE ){ |
+ 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; |
+ if( p->pDirty==0 && p->bPurgeable ){ |
+ assert( p->eCreate==1 ); |
+ p->eCreate = 2; |
+ } |
+ } |
+ pPage->pDirtyNext = 0; |
+ pPage->pDirtyPrev = 0; |
+ } |
+ if( addRemove & PCACHE_DIRTYLIST_ADD ){ |
+ 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; |
+ }else{ |
+ p->pDirtyTail = pPage; |
+ if( p->bPurgeable ){ |
+ assert( p->eCreate==2 ); |
+ p->eCreate = 1; |
+ } |
+ } |
+ p->pDirty = pPage; |
+ if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){ |
+ p->pSynced = pPage; |
+ } |
+ } |
+} |
+ |
+/* |
+** 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){ |
+ if( p->pCache->bPurgeable ){ |
+ if( p->pgno==1 ){ |
+ p->pCache->pPage1 = 0; |
+ } |
+ sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 0); |
+ } |
+} |
+ |
+/* |
+** 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)); |
+ } |
+} |
+ |
+/*************************************************** 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(). |
+*/ |
+int 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 = 1; |
+ p->szExtra = szExtra; |
+ p->bPurgeable = bPurgeable; |
+ p->eCreate = 2; |
+ p->xStress = xStress; |
+ p->pStress = pStress; |
+ p->szCache = 100; |
+ return sqlite3PcacheSetPageSize(p, szPage); |
+} |
+ |
+/* |
+** Change the page size for PCache object. The caller must ensure that there |
+** are no outstanding page references when this function is called. |
+*/ |
+int sqlite3PcacheSetPageSize(PCache *pCache, int szPage){ |
+ assert( pCache->nRef==0 && pCache->pDirty==0 ); |
+ if( pCache->szPage ){ |
+ sqlite3_pcache *pNew; |
+ pNew = sqlite3GlobalConfig.pcache2.xCreate( |
+ szPage, pCache->szExtra + sizeof(PgHdr), pCache->bPurgeable |
+ ); |
+ if( pNew==0 ) return SQLITE_NOMEM; |
+ sqlite3GlobalConfig.pcache2.xCachesize(pNew, numberOfCachePages(pCache)); |
+ if( pCache->pCache ){ |
+ sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache); |
+ } |
+ pCache->pCache = pNew; |
+ pCache->pPage1 = 0; |
+ pCache->szPage = szPage; |
+ } |
+ return SQLITE_OK; |
+} |
+ |
+/* |
+** Try to obtain a page from the cache. |
+** |
+** This routine returns a pointer to an sqlite3_pcache_page object if |
+** such an object is already in cache, or if a new one is created. |
+** This routine returns a NULL pointer if the object was not in cache |
+** and could not be created. |
+** |
+** The createFlags should be 0 to check for existing pages and should |
+** be 3 (not 1, but 3) to try to create a new page. |
+** |
+** If the createFlag is 0, then NULL is always returned if the page |
+** is not already in the cache. If createFlag is 1, then a new page |
+** is created only if that can be done without spilling dirty pages |
+** and without exceeding the cache size limit. |
+** |
+** The caller needs to invoke sqlite3PcacheFetchFinish() to properly |
+** initialize the sqlite3_pcache_page object and convert it into a |
+** PgHdr object. The sqlite3PcacheFetch() and sqlite3PcacheFetchFinish() |
+** routines are split this way for performance reasons. When separated |
+** they can both (usually) operate without having to push values to |
+** the stack on entry and pop them back off on exit, which saves a |
+** lot of pushing and popping. |
+*/ |
+sqlite3_pcache_page *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 */ |
+){ |
+ int eCreate; |
+ |
+ assert( pCache!=0 ); |
+ assert( pCache->pCache!=0 ); |
+ assert( createFlag==3 || createFlag==0 ); |
+ assert( pgno>0 ); |
+ |
+ /* eCreate defines what to do if the page does not exist. |
+ ** 0 Do not allocate a new page. (createFlag==0) |
+ ** 1 Allocate a new page if doing so is inexpensive. |
+ ** (createFlag==1 AND bPurgeable AND pDirty) |
+ ** 2 Allocate a new page even it doing so is difficult. |
+ ** (createFlag==1 AND !(bPurgeable AND pDirty) |
+ */ |
+ eCreate = createFlag & pCache->eCreate; |
+ assert( eCreate==0 || eCreate==1 || eCreate==2 ); |
+ assert( createFlag==0 || pCache->eCreate==eCreate ); |
+ assert( createFlag==0 || eCreate==1+(!pCache->bPurgeable||!pCache->pDirty) ); |
+ return sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate); |
+} |
+ |
+/* |
+** If the sqlite3PcacheFetch() routine is unable to allocate a new |
+** page because new clean pages are available for reuse and the cache |
+** size limit has been reached, then this routine can be invoked to |
+** try harder to allocate a page. This routine might invoke the stress |
+** callback to spill dirty pages to the journal. It will then try to |
+** allocate the new page and will only fail to allocate a new page on |
+** an OOM error. |
+** |
+** This routine should be invoked only after sqlite3PcacheFetch() fails. |
+*/ |
+int sqlite3PcacheFetchStress( |
+ PCache *pCache, /* Obtain the page from this cache */ |
+ Pgno pgno, /* Page number to obtain */ |
+ sqlite3_pcache_page **ppPage /* Write result here */ |
+){ |
+ PgHdr *pPg; |
+ if( pCache->eCreate==2 ) return 0; |
+ |
+ |
+ /* 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. |
+ */ |
+ 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; |
+ } |
+ } |
+ *ppPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2); |
+ return *ppPage==0 ? SQLITE_NOMEM : SQLITE_OK; |
+} |
+ |
+/* |
+** This is a helper routine for sqlite3PcacheFetchFinish() |
+** |
+** In the uncommon case where the page being fetched has not been |
+** initialized, this routine is invoked to do the initialization. |
+** This routine is broken out into a separate function since it |
+** requires extra stack manipulation that can be avoided in the common |
+** case. |
+*/ |
+static SQLITE_NOINLINE PgHdr *pcacheFetchFinishWithInit( |
+ PCache *pCache, /* Obtain the page from this cache */ |
+ Pgno pgno, /* Page number obtained */ |
+ sqlite3_pcache_page *pPage /* Page obtained by prior PcacheFetch() call */ |
+){ |
+ PgHdr *pPgHdr; |
+ assert( pPage!=0 ); |
+ pPgHdr = (PgHdr*)pPage->pExtra; |
+ assert( pPgHdr->pPage==0 ); |
+ 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; |
+ return sqlite3PcacheFetchFinish(pCache,pgno,pPage); |
+} |
+ |
+/* |
+** This routine converts the sqlite3_pcache_page object returned by |
+** sqlite3PcacheFetch() into an initialized PgHdr object. This routine |
+** must be called after sqlite3PcacheFetch() in order to get a usable |
+** result. |
+*/ |
+PgHdr *sqlite3PcacheFetchFinish( |
+ PCache *pCache, /* Obtain the page from this cache */ |
+ Pgno pgno, /* Page number obtained */ |
+ sqlite3_pcache_page *pPage /* Page obtained by prior PcacheFetch() call */ |
+){ |
+ PgHdr *pPgHdr; |
+ |
+ if( pPage==0 ) return 0; |
+ pPgHdr = (PgHdr *)pPage->pExtra; |
+ |
+ if( !pPgHdr->pPage ){ |
+ return pcacheFetchFinishWithInit(pCache, pgno, pPage); |
+ } |
+ if( 0==pPgHdr->nRef ){ |
+ pCache->nRef++; |
+ } |
+ pPgHdr->nRef++; |
+ if( pgno==1 ){ |
+ pCache->pPage1 = pPgHdr; |
+ } |
+ return pPgHdr; |
+} |
+ |
+/* |
+** Decrement the reference count on a page. If the page is clean and the |
+** reference count drops to 0, then it is made eligible for recycling. |
+*/ |
+void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){ |
+ assert( p->nRef>0 ); |
+ p->nRef--; |
+ if( p->nRef==0 ){ |
+ p->pCache->nRef--; |
+ if( (p->flags&PGHDR_DIRTY)==0 ){ |
+ pcacheUnpin(p); |
+ }else if( p->pDirtyPrev!=0 ){ |
+ /* Move the page to the head of the dirty list. */ |
+ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT); |
+ } |
+ } |
+} |
+ |
+/* |
+** 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){ |
+ assert( p->nRef==1 ); |
+ if( p->flags&PGHDR_DIRTY ){ |
+ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); |
+ } |
+ p->pCache->nRef--; |
+ if( p->pgno==1 ){ |
+ p->pCache->pPage1 = 0; |
+ } |
+ sqlite3GlobalConfig.pcache2.xUnpin(p->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; |
+ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD); |
+ } |
+} |
+ |
+/* |
+** 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) ){ |
+ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE); |
+ 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) ){ |
+ pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT); |
+ } |
+} |
+ |
+/* |
+** 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){ |
+ assert( pCache->pCache!=0 ); |
+ 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){ |
+ assert( pCache->pCache!=0 ); |
+ return sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache); |
+} |
+ |
+#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){ |
+ assert( pCache->pCache!=0 ); |
+ pCache->szCache = mxPage; |
+ sqlite3GlobalConfig.pcache2.xCachesize(pCache->pCache, |
+ numberOfCachePages(pCache)); |
+} |
+ |
+/* |
+** Free up as much memory as possible from the page cache. |
+*/ |
+void sqlite3PcacheShrink(PCache *pCache){ |
+ assert( pCache->pCache!=0 ); |
+ 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 |