From: drh <drh@noemail.net>
Date: Mon, 17 May 2010 15:52:44 +0000 (+0000)
Subject: An improvement to the SQLITE_FCNTL_SIZE_HINT change that invokes the hint
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=90e38fde1831333130f9bbc2704c526b124f6e9a;p=thirdparty%2Fsqlite.git

An improvement to the SQLITE_FCNTL_SIZE_HINT change that invokes the hint
less often and only when really needed.

FossilOrigin-Name: a1d20ceb9c195ea96f09c2a40c898ca75f504ee1
---

diff --git a/manifest b/manifest
index abd2714ed8..7c695c13c8 100644
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Invoke\sthe\sSQLITE_FCNTL_SIZE_HINT\sopcode\son\sthe\ssqlite3_file_control()\ninterface\sfor\sdatabase\sfiles\sbefore\sextending\sthe\ssize\sof\sthe\sfile.\s\sThe\nVFS\scan\suse\sthis\shint\sto\spreallocate\sspace.
-D 2010-05-17T15:33:24
+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
 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 a7470e877d927f708e93b031c90aacde57bf08a2
+F src/pager.c e6b49d1b0116c186694093169d3c7199b0a72e4d
 F src/pager.h 588c1ac195228b2da45c4e5f7ab6c2fd253d1751
 F src/parse.y d962e544d9953289db23c1d4cc2dab514c7136fa
 F src/pragma.c 6e207b4f69901089758c02c02e0bf86ed12a4d8f
@@ -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 527c71d54e32ea022231af67ce437faa60acb14a
-R 0717702a9a1a1a5e4f623dea107fa5c2
+P 9a083711712d652613c93b3ad96d4f7361376c7f
+R aea3444cc6c24b1c4506b5c6f93e797e
 U drh
-Z fc5ea82c1897889c855a0d6e1b3eaced
+Z 528ef0641d2748215fd8a1354579cc0a
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 Version: GnuPG v1.4.6 (GNU/Linux)
 
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diff --git a/manifest.uuid b/manifest.uuid
index f510949642..ff86b4fc06 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9a083711712d652613c93b3ad96d4f7361376c7f
\ No newline at end of file
+a1d20ceb9c195ea96f09c2a40c898ca75f504ee1
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index dc4ce0251e..61b52b2ef2 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -3032,7 +3032,6 @@ static int pager_write_pagelist(PgHdr *pList){
   Pager *pPager;
   PgHdr *p;
   int rc;
-  sqlite3_int64 szFile;          /* Final size of databsae file */
 
   if( pList==0 ) return SQLITE_OK;
   pPager = pList->pPager;
@@ -3063,24 +3062,23 @@ static int pager_write_pagelist(PgHdr *pList){
     assert( p->dirty );
     p->dirty = 0;
   }
-  szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
-  while( pList ){
 
-    /* If the file has not yet been opened, open it now. */
-    if( !pPager->fd->pMethods ){
-      assert(pPager->tempFile);
-      rc = sqlite3PagerOpentemp(pPager, pPager->fd, pPager->vfsFlags);
-      if( rc ) return rc;
-    }
+  /* If the file has not yet been opened, open it now. */
+  if( !pPager->fd->pMethods ){
+    assert(pPager->tempFile);
+    rc = sqlite3PagerOpentemp(pPager, pPager->fd, pPager->vfsFlags);
+    if( rc ) return rc;
+  }
 
-    /* Before the first write, give the VFS a hint of what the final
-    ** file size will be.
-    */
-    if( szFile>0 ){
-      sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
-      szFile = 0;
-    }
+  /* 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;
+    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
+  }
 
+  while( pList ){
     /* If there are dirty pages in the page cache with page numbers greater
     ** than Pager.dbSize, this means sqlite3PagerTruncate() was called to
     ** make the file smaller (presumably by auto-vacuum code). Do not write