Import SQLite 3.7.6.3.

third_party/sqlite/src/src/pcache.c

Index: third_party/sqlite/src/src/pcache.c
diff --git a/third_party/sqlite/src/src/pcache.c b/third_party/sqlite/src/src/pcache.c
index 4f0478b6b45487ae2859e2158b7df0b1a6db2166..6dec5506843b3093161ec8a574066bbdc5505356 100644
--- a/third_party/sqlite/src/src/pcache.c
+++ b/third_party/sqlite/src/src/pcache.c
@@ -10,8 +10,6 @@
 **
 *************************************************************************
 ** This file implements that page cache.
-**
-** @(#) $Id: pcache.c,v 1.47 2009/07/25 11:46:49 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 
@@ -144,12 +142,16 @@ static void pcacheUnpin(PgHdr *p){
 */
 int sqlite3PcacheInitialize(void){
   if( sqlite3GlobalConfig.pcache.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);
 }
 void sqlite3PcacheShutdown(void){
   if( sqlite3GlobalConfig.pcache.xShutdown ){
+    /* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */
     sqlite3GlobalConfig.pcache.xShutdown(sqlite3GlobalConfig.pcache.pArg);
   }
 }
@@ -191,6 +193,7 @@ void sqlite3PcacheSetPageSize(PCache *pCache, int szPage){
   if( pCache->pCache ){
     sqlite3GlobalConfig.pcache.xDestroy(pCache->pCache);
     pCache->pCache = 0;
+    pCache->pPage1 = 0;
   }
   pCache->szPage = szPage;
 }
@@ -244,6 +247,7 @@ int sqlite3PcacheFetch(
         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);
     }
@@ -260,15 +264,17 @@ int sqlite3PcacheFetch(
 
   if( pPage ){
     if( !pPage->pData ){
-      memset(pPage, 0, sizeof(PgHdr) + pCache->szExtra);
-      pPage->pExtra = (void*)&pPage[1];
-      pPage->pData = (void *)&((char *)pPage)[sizeof(PgHdr) + pCache->szExtra];
+      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;
     }
     assert( pPage->pCache==pCache );
     assert( pPage->pgno==pgno );
-    assert( pPage->pExtra==(void *)&pPage[1] );
+    assert( pPage->pData==(void *)&pPage[1] );
+    assert( pPage->pExtra==(void *)&((char *)&pPage[1])[pCache->szPage] );
 
     if( 0==pPage->nRef ){
       pCache->nRef++;
@@ -407,7 +413,12 @@ void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){
     PgHdr *pNext;
     for(p=pCache->pDirty; p; p=pNext){
       pNext = p->pDirtyNext;
-      if( p->pgno>pgno ){
+      /* 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);
       }