Speed improvement: do not journal or rollback pages that are pulled out of

the freelist. (CVS 3531)

FossilOrigin-Name: 4dffc4c3c9c4ccc024669cec204c68e953333563

manifest

@@ -1,5 +1,5 @@
-C Updates\sto\sthe\s"Distinctive\sFeatures"\sdocument.\s(CVS\s3530)
-D 2006-12-18T14:12:21
+C Speed\simprovement:\sdo\snot\sjournal\sor\srollback\spages\sthat\sare\spulled\sout\sof\nthe\sfreelist.\s(CVS\s3531)
+D 2006-12-18T18:34:51
 F Makefile.in 8e14898d41a53033ecb687d93c9cd5d109fb9ae3
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -57,7 +57,7 @@ F src/alter.c 2c79ec40f65e33deaf90ca493422c74586e481a3
 F src/analyze.c 7d2b7ab9a9c2fd6e55700f69064dfdd3e36d7a8a
 F src/attach.c b11eb4d5d3fb99a10a626956bccc7215f6b68b16
 F src/auth.c 902f4722661c796b97f007d9606bd7529c02597f
-F src/btree.c 116f748ee11ba4d3630882102e99b60ff58d2a84
+F src/btree.c e7d1694ad0844918e20b802a249533789bf811dc
 F src/btree.h 061c50e37de7f50b58528e352d400cf33ead7418
 F src/build.c 02aedde724dc73295d6e9b8dc29afb5dd38de507
 F src/callback.c fd9bb39f7ff6b52bad8365617abc61c720640429
@@ -85,7 +85,7 @@ F src/os_unix.c d3b6b66b79777c9177d76bd5c68c227978c4593c
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c cac5f9b60faacd46874aa8dfefdb7dc4d0437ff9
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c 18c9cb43b3e740c63eaa13da41c52926012e4853
+F src/pager.c 814268d5bbd69f30069867142f1d460b8b7ab778
 F src/pager.h 2e6d42f4ae004ae748a037b8468112b851c447a7
 F src/parse.y 9b3d1c0f8af81fe0cc909baf226865baa725bb23
 F src/pragma.c d0891d3504b6291b506a5ec2226bbf79ffcef003
@@ -423,7 +423,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 7393c81b8cb9d4344ae744de9eabcb3af64f1db8
-R 90435cd6f785c0f1944fcee4b97ba9dc
+P c734585e1a801bec2d393d000c323ba842c2292d
+R f4b3ee85fc3b4b1abd3912c81ea3b7d4
 U drh
-Z 785f3b918eb47031e16bc31d88bf41e9
+Z b8975ee2a0ac067044f47c4bbda872fe

manifest.uuid

@@ -1 +1 @@
-c734585e1a801bec2d393d000c323ba842c2292d
+4dffc4c3c9c4ccc024669cec204c68e953333563

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.331 2006/11/30 13:05:29 drh Exp $
+** $Id: btree.c,v 1.332 2006/12/18 18:34:51 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -421,7 +421,8 @@ struct BtCursor {
 */
 #if SQLITE_TEST
 # define TRACE(X)   if( sqlite3_btree_trace )\
-                        { sqlite3DebugPrintf X; fflush(stdout); }
+/*                        { sqlite3DebugPrintf X; fflush(stdout); } */ \
+{ printf X; fflush(stdout); }
 int sqlite3_btree_trace=0;  /* True to enable tracing */
 #else
 # define TRACE(X)
@@ -3569,14 +3570,14 @@ static int allocatePage(
   int rc;
   int n;     /* Number of pages on the freelist */
   int k;     /* Number of leaves on the trunk of the freelist */
+  MemPage *pTrunk = 0;
+  MemPage *pPrevTrunk = 0;
 
   pPage1 = pBt->pPage1;
   n = get4byte(&pPage1->aData[36]);
   if( n>0 ){
     /* There are pages on the freelist.  Reuse one of those pages. */
-    MemPage *pTrunk = 0;
     Pgno iTrunk;
-    MemPage *pPrevTrunk = 0;
     u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
     
     /* If the 'exact' parameter was true and a query of the pointer-map
@@ -3617,16 +3618,8 @@ static int allocatePage(
       }
       rc = getPage(pBt, iTrunk, &pTrunk);
       if( rc ){
-        releasePage(pPrevTrunk);
-        return rc;
-      }
-
-      /* TODO: This should move to after the loop? */
-      rc = sqlite3pager_write(pTrunk->aData);
-      if( rc ){
-        releasePage(pTrunk);
-        releasePage(pPrevTrunk);
-        return rc;
+        pTrunk = 0;
+        goto end_allocate_page;
       }
 
       k = get4byte(&pTrunk->aData[4]);
@@ -3635,6 +3628,10 @@ static int allocatePage(
         ** So extract the trunk page itself and use it as the newly 
         ** allocated page */
         assert( pPrevTrunk==0 );
+        rc = sqlite3pager_write(pTrunk->aData);
+        if( rc ){
+          goto end_allocate_page;
+        }
         *pPgno = iTrunk;
         memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
         *ppPage = pTrunk;
@@ -3642,7 +3639,8 @@ static int allocatePage(
         TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
       }else if( k>pBt->usableSize/4 - 8 ){
         /* Value of k is out of range.  Database corruption */
-        return SQLITE_CORRUPT_BKPT;
+        rc = SQLITE_CORRUPT_BKPT;
+        goto end_allocate_page;
 #ifndef SQLITE_OMIT_AUTOVACUUM
       }else if( searchList && nearby==iTrunk ){
         /* The list is being searched and this trunk page is the page
@@ -3651,6 +3649,10 @@ static int allocatePage(
         assert( *pPgno==iTrunk );
         *ppPage = pTrunk;
         searchList = 0;
+        rc = sqlite3pager_write(pTrunk->aData);
+        if( rc ){
+          goto end_allocate_page;
+        }
         if( k==0 ){
           if( !pPrevTrunk ){
             memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
@@ -3666,26 +3668,26 @@ static int allocatePage(
           Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);
           rc = getPage(pBt, iNewTrunk, &pNewTrunk);
           if( rc!=SQLITE_OK ){
-            releasePage(pTrunk);
-            releasePage(pPrevTrunk);
-            return rc;
+            goto end_allocate_page;
           }
           rc = sqlite3pager_write(pNewTrunk->aData);
           if( rc!=SQLITE_OK ){
             releasePage(pNewTrunk);
-            releasePage(pTrunk);
-            releasePage(pPrevTrunk);
-            return rc;
+            goto end_allocate_page;
           }
           memcpy(&pNewTrunk->aData[0], &pTrunk->aData[0], 4);
           put4byte(&pNewTrunk->aData[4], k-1);
           memcpy(&pNewTrunk->aData[8], &pTrunk->aData[12], (k-1)*4);
+          releasePage(pNewTrunk);
           if( !pPrevTrunk ){
             put4byte(&pPage1->aData[32], iNewTrunk);
           }else{
+            rc = sqlite3pager_write(pPrevTrunk->aData);
+            if( rc ){
+              goto end_allocate_page;
+            }
             put4byte(&pPrevTrunk->aData[0], iNewTrunk);
           }
-          releasePage(pNewTrunk);
         }
         pTrunk = 0;
         TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
@@ -3695,6 +3697,10 @@ static int allocatePage(
         int closest;
         Pgno iPage;
         unsigned char *aData = pTrunk->aData;
+        rc = sqlite3pager_write(aData);
+        if( rc ){
+          goto end_allocate_page;
+        }
         if( nearby>0 ){
           int i, dist;
           closest = 0;
@@ -3738,8 +3744,8 @@ static int allocatePage(
         }
       }
       releasePage(pPrevTrunk);
+      pPrevTrunk = 0;
     }while( searchList );
-    releasePage(pTrunk);
   }else{
     /* There are no pages on the freelist, so create a new page at the
     ** end of the file */
@@ -3768,6 +3774,10 @@ static int allocatePage(
   }
 
   assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
+
+end_allocate_page:
+  releasePage(pTrunk);
+  releasePage(pPrevTrunk);
   return rc;
 }
 

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.276 2006/11/23 11:58:44 drh Exp $
+** @(#) $Id: pager.c,v 1.277 2006/12/18 18:34:51 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -31,6 +31,7 @@
 ** Macros for troubleshooting.  Normally turned off
 */
 #if 0
+#define sqlite3DebugPrintf printf
 #define TRACE1(X)       sqlite3DebugPrintf(X)
 #define TRACE2(X,Y)     sqlite3DebugPrintf(X,Y)
 #define TRACE3(X,Y,Z)   sqlite3DebugPrintf(X,Y,Z)
@@ -3335,7 +3336,8 @@ void sqlite3pager_dont_rollback(void *pData){
   PgHdr *pPg = DATA_TO_PGHDR(pData);
   Pager *pPager = pPg->pPager;
 
-  if( pPager->state!=PAGER_EXCLUSIVE || pPager->journalOpen==0 ) return;
+  assert( pPager->state>=PAGER_RESERVED );
+  if( pPager->journalOpen==0 ) return;
   if( pPg->alwaysRollback || pPager->alwaysRollback || MEMDB ) return;
   if( !pPg->inJournal && (int)pPg->pgno <= pPager->origDbSize ){
     assert( pPager->aInJournal!=0 );