From: drh <drh@noemail.net>
Date: Tue, 18 May 2010 12:37:05 +0000 (+0000)
Subject: Keep additional state information in the pager in an effort to reduce the
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fheads%2Fbranch-3.6.1-exp;p=thirdparty%2Fsqlite.git

Keep additional state information in the pager in an effort to reduce the
number of SQLITE_FCNTL_SIZE_HINTs.

FossilOrigin-Name: 97d88a86e45e7a4269efd2fafdd4e6081d1475f8
---

diff --git a/manifest b/manifest
index 7c695c13c8..745d52cd29 100644
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C An\simprovement\sto\sthe\sSQLITE_FCNTL_SIZE_HINT\schange\sthat\sinvokes\sthe\shint\nless\soften\sand\sonly\swhen\sreally\sneeded.
-D 2010-05-17T15:52:44
+C Keep\sadditional\sstate\sinformation\sin\sthe\spager\sin\san\seffort\sto\sreduce\sthe\nnumber\sof\sSQLITE_FCNTL_SIZE_HINTs.
+D 2010-05-18T12:37:05
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 2713ea64947be3b35f35d9a3158bb8299c90b019
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -138,7 +138,7 @@ F src/os_common.h 24525d8b7bce66c374dfc1810a6c9043f3359b60
 F src/os_os2.c 676ed273b17bd260f905df81375c9f9950d85517
 F src/os_unix.c 23b64faec0762bdc878c8ea61ab38d4ae9575318
 F src/os_win.c aefe9ee26430678a19a058a874e4e2bd91398142
-F src/pager.c e6b49d1b0116c186694093169d3c7199b0a72e4d
+F src/pager.c c78c9558060ca045eb973f9b87da70a0ac28992a
 F src/pager.h 588c1ac195228b2da45c4e5f7ab6c2fd253d1751
 F src/parse.y d962e544d9953289db23c1d4cc2dab514c7136fa
 F src/pragma.c 6e207b4f69901089758c02c02e0bf86ed12a4d8f
@@ -371,7 +371,7 @@ F test/insert4.test 6e382eaf7295a4463e6f29ea20fcd8e63d097eeb
 F test/insert5.test 1f93cbe9742110119133d7e8e3ccfe6d7c249766
 F test/interrupt.test 42e7cf98646fd9cb4a3b131a93ed3c50b9e149f1
 F test/intpkey.test 537669fd535f62632ca64828e435b9e54e8d677f
-F test/io.test fb8b310ff1bb9bedf2b66f7e8c01b48cf980b28f
+F test/io.test b9d9d627db72ded2227e23bf03b45067047f9d8b
 F test/ioerr.test b42f249c9181b5864e53fdae38ef75475d71c66f
 F test/ioerr2.test 5598405c48842c6c0187daad9eb49eff2c54f80d
 F test/ioerr3.test d3cec5e1a11ad6d27527d0d38573fbff14c71bdd
@@ -620,14 +620,14 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 9a083711712d652613c93b3ad96d4f7361376c7f
-R aea3444cc6c24b1c4506b5c6f93e797e
+P a1d20ceb9c195ea96f09c2a40c898ca75f504ee1
+R c259aebb9828e6f7d53c890c0f40fdc0
 U drh
-Z 528ef0641d2748215fd8a1354579cc0a
+Z 4822e36c81dd65a9c9827d7899fd3725
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.6 (GNU/Linux)
 
-iD4DBQFL8WZPoxKgR168RlERAsElAJdzpp/0CbCiHpVVmJdP1OrACx5BAJ9I1u53
-hQ/7mwNPgaNvk1lSyt7EQQ==
-=34QZ
+iD8DBQFL8on0oxKgR168RlERAth0AJ9D0mKQbfnHqPlltZbvAMr/uU7AwgCfdTA5
+llbwG9OuQTdAiZSIr/wVN/w=
+=xMw6
 -----END PGP SIGNATURE-----
diff --git a/manifest.uuid b/manifest.uuid
index ff86b4fc06..9ddf3cc9e9 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a1d20ceb9c195ea96f09c2a40c898ca75f504ee1
\ No newline at end of file
+97d88a86e45e7a4269efd2fafdd4e6081d1475f8
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index 61b52b2ef2..b302ffc17b 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -358,6 +358,7 @@ struct Pager {
   int errCode;                /* One of several kinds of errors */
   int dbSize;                 /* Number of pages in the file */
   int origDbSize;             /* dbSize before the current change */
+  int hintDbSize;             /* dbSize sent to SQLITE_FCNTL_SIZE_HINT */
   int stmtSize;               /* Size of database (in pages) at stmt_begin() */
   int nRec;                   /* Number of pages written to the journal */
   u32 cksumInit;              /* Quasi-random value added to every checksum */
@@ -1358,6 +1359,7 @@ static void pager_unlock(Pager *pPager){
         pPager->journalStarted = 0;
         pPager->stmtAutoopen = 0;
         pPager->origDbSize = 0;
+        pPager->hintDbSize = 0;
       }
     }
 
@@ -1457,6 +1459,7 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
     pPager->state = PAGER_EXCLUSIVE;
   }
   pPager->origDbSize = 0;
+  pPager->hintDbSize = 0;
   pPager->setMaster = 0;
   pPager->needSync = 0;
   lruListSetFirstSynced(pPager);
@@ -3032,6 +3035,8 @@ static int pager_write_pagelist(PgHdr *pList){
   Pager *pPager;
   PgHdr *p;
   int rc;
+  Pgno mxPgno;           /* Maximum page number to be written */
+  int nExtend = 0;       /* Number of pages on pList that extend the file */
 
   if( pList==0 ) return SQLITE_OK;
   pPager = pList->pPager;
@@ -3061,6 +3066,8 @@ static int pager_write_pagelist(PgHdr *pList){
   for(p=pList; p; p=p->pDirty){
     assert( p->dirty );
     p->dirty = 0;
+    mxPgno = p->pgno;
+    if( p->pgno>pPager->hintDbSize ) nExtend++;
   }
 
   /* If the file has not yet been opened, open it now. */
@@ -3073,9 +3080,13 @@ static int pager_write_pagelist(PgHdr *pList){
   /* Before the first write, give the VFS a hint of what the final
   ** file size will be.
   */
-  if( pPager->dbSize > (pPager->origDbSize+1) ){
-    sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
+  if( nExtend>1 || (nExtend==1 && pPager->dbSize>mxPgno) ){
+    sqlite3_int64 szFile;
+    assert( pPager->hintDbSize<mxPgno );
+    assert( mxPgno<=pPager->dbSize );
+    szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
     sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
+    pPager->hintDbSize = pPager->dbSize;
   }
 
   while( pList ){
@@ -4025,7 +4036,7 @@ static int pager_open_journal(Pager *pPager){
     rc = pPager->errCode;
     goto failed_to_open_journal;
   }
-  pPager->origDbSize = pPager->dbSize;
+  pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
 
   rc = writeJournalHdr(pPager);
 
@@ -4083,7 +4094,7 @@ int sqlite3PagerBegin(DbPage *pPg, int exFlag){
     assert( pPager->pInJournal==0 );
     if( MEMDB ){
       pPager->state = PAGER_EXCLUSIVE;
-      pPager->origDbSize = pPager->dbSize;
+      pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
     }else{
       rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
       if( rc==SQLITE_OK ){
@@ -4112,6 +4123,7 @@ int sqlite3PagerBegin(DbPage *pPg, int exFlag){
     */
     assert( pPager->nRec==0 );
     assert( pPager->origDbSize==0 );
+    assert( pPager->hintDbSize==0 );
     assert( pPager->pInJournal==0 );
     sqlite3PagerPagecount(pPager, 0);
     pagerLeave(pPager);
@@ -4120,7 +4132,7 @@ int sqlite3PagerBegin(DbPage *pPg, int exFlag){
     if( !pPager->pInJournal ){
       rc = SQLITE_NOMEM;
     }else{
-      pPager->origDbSize = pPager->dbSize;
+      pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
       rc = writeJournalHdr(pPager);
     }
   }
@@ -4915,7 +4927,7 @@ int sqlite3PagerRollback(Pager *pPager){
     }
     pPager->pDirty = 0;
     pPager->pStmt = 0;
-    pPager->dbSize = pPager->origDbSize;
+    pPager->dbSize = pPager->hintDbSize = pPager->origDbSize;
     pager_truncate_cache(pPager);
     pPager->stmtInUse = 0;
     pPager->state = PAGER_SHARED;
diff --git a/test/io.test b/test/io.test
index 603be8e726..99cf65d84b 100644
--- a/test/io.test
+++ b/test/io.test
@@ -401,7 +401,7 @@ ifcapable pager_pragmas {
     # File has grown - showing there was a cache-spill - but there 
     # have been no calls to fsync():
     list [file size test.db] [nSync]
-  } {38912 0}
+  } {36864 0}
   do_test io-3.3 {
     # The COMMIT requires a single fsync() - to the database file.
     execsql { COMMIT }