Speed improvements for in-memory databases by omitting flag clearing on pages

where it is impossible for the flag to be set and by avoiding assert()s on
non-debugging builds.  Ticket #3384. (CVS 5715)

FossilOrigin-Name: a7fd9e622bc1050e78f227ec42b6ba90c87c865a

diff --git a/manifest b/manifest
index d7699b7c1c7c47b79d980c2e07958ca2816eb871..26524642a9d2d1fdf8fcced740f5eb3251dc5e32 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Changes\sto\stest\sscripts\sto\ssupport\srunning\son\ssymbian.\s(CVS\s5714)
-D 2008-09-17T16:14:10
+C Speed\simprovements\sfor\sin-memory\sdatabases\sby\somitting\sflag\sclearing\son\spages\nwhere\sit\sis\simpossible\sfor\sthe\sflag\sto\sbe\sset\sand\sby\savoiding\sassert()s\son\nnon-debugging\sbuilds.\s\sTicket\s#3384.\s(CVS\s5715)
+D 2008-09-17T20:06:26
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in d15a7ebfe5e057a72a49805ffb302dbb601c8329
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -137,11 +137,11 @@ F src/os_common.h 24525d8b7bce66c374dfc1810a6c9043f3359b60
 F src/os_os2.c e391fc95adc744bbdcefd4d11e3066998185a0a0
 F src/os_unix.c 8f4def6a92681735908fa1b87b5cc0291ebafde6
 F src/os_win.c 3209dc0ed734291764393ea8d534ba0d8696a540
-F src/pager.c f21654d1fcfd62ce058dbb88d07159745dc5bd84
+F src/pager.c 34318b85cead25e179a6ff83092c79d6dcecb2fd
 F src/pager.h c45380ca9d0933ea5bc4ecb3a43958b6d2ec5a9c
 F src/parse.y d0f76d2cb8d6883d5600dc20beb961a6022b94b8
-F src/pcache.c a39908e73cf5001dec2cc7a55a477fe8e8611db9
-F src/pcache.h 53730c33310cdf7a5c94e8333c853d59a3b30226
+F src/pcache.c c799d753a5d4b913961a4fe66c8a7c706b04d28d
+F src/pcache.h deddea69babf3e0931b11eea3bf5c9e33a654389
 F src/pragma.c e633b6b7dabc110e2abfed4e35ba34a4039cb65c
 F src/prepare.c c7e00ed1b0bdcf699b1aad651247d4dc3d281b0b
 F src/printf.c 785f87120589c1db672e37c6eb1087c456e6f84d
@@ -637,7 +637,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 94fde77b9a4efde5f7fb2a84fedaf38b0ebbac70
-R 5cb1f4f412c11fd992c399fc6668cf38
-U danielk1977
-Z f12860bdb96f15ad02a57af76d19c3b1
+P 6ef34e9d3118965781c69011deaede1ebbb19b12
+R a27713f2ccd1c6c2e7e56fb7534b72ec
+U drh
+Z ee142ff5e27b59538a7c71659e26324f

diff --git a/manifest.uuid b/manifest.uuid
index 49f28380e0e4366a6b8b7b6b1f79f9694d7d788d..79927879023a72d10b583df6eada8fd52025ea6b 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6ef34e9d3118965781c69011deaede1ebbb19b12
\ No newline at end of file
+a7fd9e622bc1050e78f227ec42b6ba90c87c865a
\ No newline at end of file

diff --git a/src/pager.c b/src/pager.c
index cb2f3849ba062af01f58ad2a9c4674da43ef4d3b..51fafebd7db4d2e63b5998274ae240bd1841e55c 100644 (file)
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.490 2008/09/16 05:12:24 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.491 2008/09/17 20:06:26 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -994,8 +994,8 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
 #ifdef SQLITE_CHECK_PAGES
     sqlite3PcacheIterate(pPager->pPCache, pager_set_pagehash);
 #endif
-    sqlite3PcacheSetFlags(pPager->pPCache,
-       ~(PGHDR_IN_JOURNAL | PGHDR_NEED_SYNC), 0
+    sqlite3PcacheClearFlags(pPager->pPCache,
+       PGHDR_IN_JOURNAL | PGHDR_NEED_SYNC
     );
     pPager->dirtyCache = 0;
     pPager->nRec = 0;
@@ -1663,7 +1663,7 @@ void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 */
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
 void sqlite3PagerSetSafetyLevel(Pager *pPager, int level, int bFullFsync){
-  pPager->noSync =  level==1 || pPager->tempFile;
+  pPager->noSync =  level==1 || pPager->tempFile || MEMDB;
   pPager->fullSync = level==3 && !pPager->tempFile;
   pPager->sync_flags = (bFullFsync?SQLITE_SYNC_FULL:SQLITE_SYNC_NORMAL);
   if( pPager->noSync ) pPager->needSync = 0;
@@ -1761,6 +1761,7 @@ int sqlite3PagerOpen(
     if( strcmp(zFilename,":memory:")==0 ){
       memDb = 1;
       zPathname[0] = 0;
+      useJournal = 0;
     }else
 #endif
     {
@@ -1885,7 +1886,7 @@ int sqlite3PagerOpen(
   }
 
   /* pPager->journalOpen = 0; */
-  pPager->useJournal = useJournal && !memDb;
+  pPager->useJournal = useJournal;
   pPager->noReadlock = noReadlock && readOnly;
   /* pPager->stmtOpen = 0; */
   /* pPager->stmtInUse = 0; */
@@ -2322,8 +2323,7 @@ static int syncJournal(Pager *pPager){
 
     /* Erase the needSync flag from every page.
     */
-    sqlite3PcacheSetFlags(pPager->pPCache, ~PGHDR_NEED_SYNC, 0);
-    /* lruListSetFirstSynced(pPager); */
+    sqlite3PcacheClearFlags(pPager->pPCache, PGHDR_NEED_SYNC);
   }
 
 #ifndef NDEBUG
@@ -2333,7 +2333,6 @@ static int syncJournal(Pager *pPager){
   */
   else{
     sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_NEED_SYNC);
-    /* assert( pPager->lru.pFirstSynced==pPager->lru.pFirst ); */
   }
 #endif
 
@@ -2411,11 +2410,9 @@ static int pager_write_pagelist(PgHdr *pList){
 #ifdef SQLITE_CHECK_PAGES
     pList->pageHash = pager_pagehash(pList);
 #endif
-    /* makeClean(pList); */
     pList = pList->pDirty;
   }
 
-  /* sqlite3PcacheCleanAll(pPager->pPCache); */
   return SQLITE_OK;
 }
 
@@ -2845,6 +2842,7 @@ static int pagerAcquire(
     PAGER_INCR(pPager->nMiss);
     pPg->pPager = pPager;
     if( sqlite3BitvecTest(pPager->pInJournal, pgno) ){
+      assert( !MEMDB );
       pPg->flags |= PGHDR_IN_JOURNAL;
     }
     memset(pPg->pExtra, 0, pPager->nExtra);
@@ -3393,6 +3391,7 @@ int sqlite3PagerWrite(DbPage *pDbPage){
     ** before any of them can be written out to the database file.
     */
     if( needSync ){
+      assert( !MEMDB && pPager->noSync==0 );
       for(ii=0; ii<nPage && needSync; ii++){
         PgHdr *pPage = pager_lookup(pPager, pg1+ii);
         if( pPage ) pPage->flags |= PGHDR_NEED_SYNC;
@@ -3805,9 +3804,7 @@ int sqlite3PagerCommitPhaseTwo(Pager *pPager){
   if( MEMDB ){
     sqlite3PcacheCommit(pPager->pPCache, 0);
     sqlite3PcacheCleanAll(pPager->pPCache);
-    sqlite3PcacheSetFlags(pPager->pPCache, 
-       ~(PGHDR_IN_JOURNAL | PGHDR_NEED_SYNC), 0
-    );
+    sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_IN_JOURNAL);
     pPager->state = PAGER_SHARED;
   }else{
     assert( pPager->state==PAGER_SYNCED || !pPager->dirtyCache );
@@ -3836,9 +3833,7 @@ int sqlite3PagerRollback(Pager *pPager){
     sqlite3PcacheRollback(pPager->pPCache, 1);
     sqlite3PcacheRollback(pPager->pPCache, 0);
     sqlite3PcacheCleanAll(pPager->pPCache);
-    sqlite3PcacheSetFlags(pPager->pPCache, 
-       ~(PGHDR_IN_JOURNAL | PGHDR_NEED_SYNC), 0
-    );
+    sqlite3PcacheAssertFlags(pPager->pPCache, 0, PGHDR_IN_JOURNAL);
     pPager->dbSize = pPager->origDbSize;
     pager_truncate_cache(pPager);
     pPager->stmtInUse = 0;
@@ -3976,7 +3971,6 @@ int sqlite3PagerStmtCommit(Pager *pPager){
   if( pPager->stmtInUse ){
     PAGERTRACE2("STMT-COMMIT %d\n", PAGERID(pPager));
     if( !MEMDB ){
-      /* sqlite3OsTruncate(pPager->stfd, 0); */
       sqlite3BitvecDestroy(pPager->pInStmt);
       pPager->pInStmt = 0;
     }else{
@@ -4077,7 +4071,7 @@ void sqlite3PagerSetCodec(
 **
 ** There must be no references to the page previously located at
 ** pgno (which we call pPgOld) though that page is allowed to be
-** in cache.  If the page previous located at pgno is not already
+** in cache.  If the page previously located at pgno is not already
 ** in the rollback journal, it is not put there by by this routine.
 **
 ** References to the page pPg remain valid. Updating any
@@ -4132,6 +4126,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
     pPg->flags |= (pPgOld->flags&PGHDR_NEED_SYNC);
   }
   if( sqlite3BitvecTest(pPager->pInJournal, pgno) ){
+    assert( !MEMDB );
     pPg->flags |= PGHDR_IN_JOURNAL;
   }
 
@@ -4174,6 +4169,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
       return rc;
     }
     pPager->needSync = 1;
+    assert( pPager->noSync==0 && !MEMDB );
     pPgHdr->flags |= PGHDR_NEED_SYNC;
     pPgHdr->flags |= PGHDR_IN_JOURNAL;
     makeDirty(pPgHdr);

diff --git a/src/pcache.c b/src/pcache.c
index c7c7fac78fc0bca4fee57b9db0598f492aad8f8b..29672095aa456c0ad8264dd877b85d8adf00270d 100644 (file)
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file implements that page cache.
 **
-** @(#) $Id: pcache.c,v 1.28 2008/09/17 11:02:57 danielk1977 Exp $
+** @(#) $Id: pcache.c,v 1.29 2008/09/17 20:06:26 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -875,7 +875,6 @@ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
   pcacheRemoveFromHash(p);
   p->pgno = newPgno;
   if( newPgno==0 ){
-    p->flags |= PGHDR_REUSE_UNLIKELY;
     pcacheFree(p->apSave[0]);
     pcacheFree(p->apSave[1]);
     p->apSave[0] = 0;
@@ -883,6 +882,7 @@ void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){
     if( (p->flags & PGHDR_DIRTY) ){
       pcacheMakeClean(p);
     }
+    p->flags = PGHDR_REUSE_UNLIKELY;
   }
   pcacheAddToHash(p);
   pcacheExitMutex();
@@ -1004,12 +1004,14 @@ int sqlite3PcachePreserve(PgHdr *p, int idJournal){
 */
 void sqlite3PcacheCommit(PCache *pCache, int idJournal){
   PgHdr *p;
+  int mask = idJournal==0 ? ~PGHDR_IN_JOURNAL : 0xffffff;
   pcacheEnterMutex();     /* Mutex is required to call pcacheFree() */
   for(p=pCache->pDirty; p; p=p->pNext){
     if( p->apSave[idJournal] ){
       pcacheFree(p->apSave[idJournal]);
       p->apSave[idJournal] = 0;
     }
+    p->flags &= mask;
   }
   pcacheExitMutex();
 }
@@ -1020,6 +1022,7 @@ void sqlite3PcacheCommit(PCache *pCache, int idJournal){
 void sqlite3PcacheRollback(PCache *pCache, int idJournal){
   PgHdr *p;
   int sz;
+  int mask = idJournal==0 ? ~PGHDR_IN_JOURNAL : 0xffffff;
   pcacheEnterMutex();     /* Mutex is required to call pcacheFree() */
   sz = pCache->szPage;
   for(p=pCache->pDirty; p; p=p->pNext){
@@ -1028,10 +1031,12 @@ void sqlite3PcacheRollback(PCache *pCache, int idJournal){
       pcacheFree(p->apSave[idJournal]);
       p->apSave[idJournal] = 0;
     }
+    p->flags &= mask;
   }
   pcacheExitMutex();
 }
 
+#ifndef NDEBUG
 /* 
 ** Assert flags settings on all pages.  Debugging only.
 */
@@ -1046,6 +1051,7 @@ void sqlite3PcacheAssertFlags(PCache *pCache, int trueMask, int falseMask){
     assert( (p->flags&falseMask)==0 );
   }
 }
+#endif
 
 /* 
 ** Discard the contents of the cache.
@@ -1178,24 +1184,23 @@ void sqlite3PcacheIterate(PCache *pCache, void (*xIter)(PgHdr *)){
 /* 
 ** Set flags on all pages in the page cache 
 */
-void sqlite3PcacheSetFlags(PCache *pCache, int andMask, int orMask){
+void sqlite3PcacheClearFlags(PCache *pCache, int mask){
   PgHdr *p;
 
-  assert( (orMask&PGHDR_NEED_SYNC)==0 );
-
   /* Obtain the global mutex before modifying any PgHdr.flags variables 
   ** or traversing the LRU list.
   */ 
   pcacheEnterMutex();
 
+  mask = ~mask;
   for(p=pCache->pDirty; p; p=p->pNext){
-    p->flags = (p->flags&andMask)|orMask;
+    p->flags &= mask;
   }
   for(p=pCache->pClean; p; p=p->pNext){
-    p->flags = (p->flags&andMask)|orMask;
+    p->flags &= mask;
   }
 
-  if( 0==(andMask&PGHDR_NEED_SYNC) ){
+  if( 0==(mask&PGHDR_NEED_SYNC) ){
     pCache->pSynced = pCache->pDirtyTail;
     assert( !pCache->pSynced || (pCache->pSynced->flags&PGHDR_NEED_SYNC)==0 );
   }

diff --git a/src/pcache.h b/src/pcache.h
index f01e98b89cafe686e1a171129b428186aacc2cfe..3d24025ca94f2a67d24fdef2b82f4e1208f70784 100644 (file)
--- a/src/pcache.h
+++ b/src/pcache.h
@@ -12,7 +12,7 @@
 ** This header file defines the interface that the sqlite page cache
 ** subsystem. 
 **
-** @(#) $Id: pcache.h,v 1.9 2008/08/29 09:10:03 danielk1977 Exp $
+** @(#) $Id: pcache.h,v 1.10 2008/09/17 20:06:26 drh Exp $
 */
 
 #ifndef _PCACHE_H_
@@ -53,13 +53,12 @@ struct PgHdr {
 
 /* Bit values for PgHdr.flags */
 #define PGHDR_IN_JOURNAL        0x001  /* Page is in rollback journal */
-#define PGHDR_IN_STMTJRNL       0x002  /* Page is in the statement journal */
-#define PGHDR_DIRTY             0x004  /* Page has changed */
-#define PGHDR_NEED_SYNC         0x008  /* Peed to fsync this page */
-#define PGHDR_NEED_READ         0x020  /* Content is unread */
-#define PGHDR_IS_INIT           0x040  /* pData is initialized */
-#define PGHDR_REUSE_UNLIKELY    0x080  /* Hint: Reuse is unlikely */
-#define PGHDR_DONT_WRITE        0x100  /* Do not write content to disk */
+#define PGHDR_DIRTY             0x002  /* Page has changed */
+#define PGHDR_NEED_SYNC         0x004  /* Fsync the rollback journal before
+                                       ** writing this page to the database */
+#define PGHDR_NEED_READ         0x008  /* Content is unread */
+#define PGHDR_REUSE_UNLIKELY    0x010  /* A hint that reuse is unlikely */
+#define PGHDR_DONT_WRITE        0x020  /* Do not write content to disk */
 
 /* Initialize and shutdown the page cache subsystem */
 int sqlite3PcacheInitialize(void);
@@ -122,11 +121,15 @@ PgHdr *sqlite3PcacheDirtyList(PCache*);
 /* Reset and close the cache object */
 void sqlite3PcacheClose(PCache*);
 
-/* Set flags on all pages in the page cache */
-void sqlite3PcacheSetFlags(PCache*, int andMask, int orMask);
+/* Clear flags from pages of the page cache */
+void sqlite3PcacheClearFlags(PCache*, int mask);
 
 /* Assert flags settings on all pages.  Debugging only */
-void sqlite3PcacheAssertFlags(PCache*, int trueMask, int falseMask);
+#ifndef NDEBUG
+  void sqlite3PcacheAssertFlags(PCache*, int trueMask, int falseMask);
+#else
+# define sqlite3PcacheAssertFlags(A,B,C)
+#endif
 
 /* Return true if the number of dirty pages is 0 or 1 */
 int sqlite3PcacheZeroOrOneDirtyPages(PCache*);