Performance optimizations in the pager_write() routine of pager.c.

FossilOrigin-Name: bc5febef921bd12ca7760e9d07d3be0e67140320

manifest

@@ -1,5 +1,5 @@
-C Reduce\sthe\snumber\sof\scalls\sto\sthe\ssubjRequiresPage()\sroutine\sinside\sof\spager.
+C Performance\soptimizations\sin\sthe\spager_write()\sroutine\sof\spager.c.
-D 2013-12-13T19:48:04.970
+D 2013-12-13T20:45:50.607
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -207,7 +207,7 @@ F src/os.h 4a46270a64e9193af4a0aaa3bc2c66dc07c29b3f
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
 F src/os_unix.c 60a7b3b23e6fcf83a50d1e320b280b551724e11f
 F src/os_win.c 16eac0961603182ffc10c02b39fe830126538e07
-F src/pager.c 3436cc9cce915e3fbcf9ae26a877816c2e6158f1
+F src/pager.c efa923693e958696eee69b205a20bfbc402c8480
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y acee1a9958539e21263362b194594c5255ad2fca
 F src/pcache.c f8043b433a57aba85384a531e3937a804432a346
@@ -1146,7 +1146,7 @@ F tool/vdbe-compress.tcl 0cf56e9263a152b84da86e75a5c0cdcdb7a47891
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P e00f37e2333cac5b53e17cf764ab56c4fcd5f617
+P e50ff39a93a51b5a5be4f0e82a76104b81c9e2a4
-R f4a7260efd0973fe242850b07fa047a9
+R 5bf1150c318417a348672020b2f63094
 U drh
-Z 2c603ffc4b31451da49fbf26e09993c0
+Z 1b9c31d5f496c5b0319085d207729750

manifest.uuid

@@ -1 +1 @@
-e50ff39a93a51b5a5be4f0e82a76104b81c9e2a4
+bc5febef921bd12ca7760e9d07d3be0e67140320

src/pager.c

@@ -1038,8 +1038,8 @@ static int subjRequiresPage(PgHdr *pPg){
 /*
 ** Return true if the page is already in the journal file.
 */
-static int pageInJournal(PgHdr *pPg){
+static int pageInJournal(Pager *pPager, PgHdr *pPg){
-  return sqlite3BitvecTest(pPg->pPager->pInJournal, pPg->pgno);
+  return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);
 }
 
 /*
@@ -4335,7 +4335,7 @@ static int subjournalPage(PgHdr *pPg){
     assert( isOpen(pPager->jfd) || pagerUseWal(pPager) );
     assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 );
     assert( pagerUseWal(pPager) 
-         || pageInJournal(pPg) 
+         || pageInJournal(pPager, pPg) 
          || pPg->pgno>pPager->dbOrigSize 
     );
     rc = openSubJournal(pPager);
@@ -5636,9 +5636,9 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
 ** of any open savepoints as appropriate.
 */
 static int pager_write(PgHdr *pPg){
-  void *pData = pPg->pData;
   Pager *pPager = pPg->pPager;
   int rc = SQLITE_OK;
+  int inJournal;
 
   /* This routine is not called unless a write-transaction has already 
   ** been started. The journal file may or may not be open at this point.
@@ -5674,7 +5674,8 @@ static int pager_write(PgHdr *pPg){
   ** to the journal then we can return right away.
   */
   sqlite3PcacheMakeDirty(pPg);
-  if( pageInJournal(pPg) && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){
+  inJournal = pageInJournal(pPager, pPg);
+  if( inJournal && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){
     assert( !pagerUseWal(pPager) );
   }else{
   
@@ -5682,7 +5683,7 @@ static int pager_write(PgHdr *pPg){
     ** EXCLUSIVE lock on the main database file.  Write the current page to
     ** the transaction journal if it is not there already.
     */
-    if( !pageInJournal(pPg) && !pagerUseWal(pPager) ){
+    if( !inJournal && !pagerUseWal(pPager) ){
       assert( pagerUseWal(pPager)==0 );
       if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){
         u32 cksum;
@@ -5695,7 +5696,7 @@ static int pager_write(PgHdr *pPg){
         assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
 
         assert( pPager->journalHdr<=pPager->journalOff );
-        CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
+        CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
         cksum = pager_cksum(pPager, (u8*)pData2);
 
         /* Even if an IO or diskfull error occurs while journalling the
@@ -5747,7 +5748,7 @@ static int pager_write(PgHdr *pPg){
     ** the statement journal format differs from the standard journal format
     ** in that it omits the checksums and the header.
     */
-    if( subjRequiresPage(pPg) ){
+    if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){
       rc = subjournalPage(pPg);
     }
   }
@@ -6749,7 +6750,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
   if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){
     needSyncPgno = pPg->pgno;
     assert( pPager->journalMode==PAGER_JOURNALMODE_OFF ||
-            pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );
+            pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize );
     assert( pPg->flags&PGHDR_DIRTY );
   }