Delay opening temporary pager files until they are first written. (CVS 4260)

FossilOrigin-Name: 3fb97a63ef70662abdba18ce8b480e6b0badcfb1

manifest

@@ -1,5 +1,5 @@
-C Remove\sthe\sobsolete\sstatic\smutexes.\s\sUse\sonly\sthe\slastest\sstatic\smutex\scode.\s(CVS\s4259)
+C Delay\sopening\stemporary\spager\sfiles\suntil\sthey\sare\sfirst\swritten.\s(CVS\s4260)
-D 2007-08-21T13:51:23
+D 2007-08-21T14:27:02
 F Makefile.in 0c0e53720f658c7a551046442dd7afba0b72bfbe
 F Makefile.linux-gcc 65241babba6faf1152bf86574477baab19190499
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -114,7 +114,7 @@ F src/os_unix.c 7aad42b1ee70d68034a4ac45fa822edccdc3d9e6
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c 29c0e19c1072679a4c7818c49fab2f35d2ad7747
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c bb25ee85c990241be0f321978e6c5f6b645692b2
+F src/pager.c df16604a2a8c6808cd9b309a7e1bdb556d868c8e
 F src/pager.h 53087c6fb9db01aed17c7fd044662a27507e89b8
 F src/parse.y 2d2ce439dc6184621fb0b86f4fc5aca7f391a590
 F src/pragma.c 9b989506a1b7c8aecd6befb8235e2f57a4aba7e5
@@ -220,7 +220,7 @@ F test/collate6.test 8be65a182abaac8011a622131486dafb8076e907
 F test/collate7.test e23677b1fd271505302643a98178952bb65b6f21
 F test/collate8.test 7ed2461305ac959886a064dc1e3cf15e155a183f
 F test/colmeta.test 6505c73ab58796afcb7c89ba9f429d573fbc6e53
-F test/conflict.test ac40064d46c4c259cf6c216d30aa5bcc26e7eea2
+F test/conflict.test 79b5214ef7a52f3e58a50ae5c60c37e7594d04e9
 F test/corrupt.test 18c7a995b1af76a8c8600b996257f2c7b7bff083
 F test/corrupt2.test 572f8df0303d0ce63ddad5c5c9101a83a345ae46
 F test/corrupt3.test 263e8bb04e2728df832fddf6973cf54c91db0c32
@@ -558,7 +558,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P a87f32e13e91250ab4d9366d2e9a3a7024a12fb9
+P 6225cd461cdd2132eeb480aa4deb8986b7f63c15
-R 0b7b982232326cbf89fa9a6240b3b769
+R 75c714761e5d5dec4034adbc16c873e3
-U drh
+U danielk1977
-Z 004bb3b1aa3b13212b12a95be5a80713
+Z ca42567df49c41054078dbc0243fa598

manifest.uuid

@@ -1 +1 @@
-6225cd461cdd2132eeb480aa4deb8986b7f63c15
+3fb97a63ef70662abdba18ce8b480e6b0badcfb1

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.363 2007/08/21 10:44:16 drh Exp $
+** @(#) $Id: pager.c,v 1.364 2007/08/21 14:27:02 danielk1977 Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -549,6 +549,16 @@ static int write32bits(sqlite3_file *fd, i64 offset, u32 val){
   return sqlite3OsWrite(fd, ac, 4, offset);
 }
 
+/*
+** If file pFd is open, call sqlite3OsUnlock() on it.
+*/
+static int osUnlock(sqlite3_file *pFd, int eLock){
+  if( !pFd->pMethods ){
+    return SQLITE_OK;
+  }
+  return sqlite3OsUnlock(pFd, eLock);
+}
+
 /*
 ** This function should be called when an error occurs within the pager
 ** code. The first argument is a pointer to the pager structure, the
@@ -930,7 +940,7 @@ static PgHdr *pager_lookup(Pager *pPager, Pgno pgno){
 static void pager_unlock(Pager *pPager){
   if( !pPager->exclusiveMode ){
     if( !MEMDB ){
-      sqlite3OsUnlock(pPager->fd, NO_LOCK);
+      osUnlock(pPager->fd, NO_LOCK);
       pPager->dbSize = -1;
       IOTRACE(("UNLOCK %p\n", pPager))
     }
@@ -1045,7 +1055,7 @@ static int pager_end_transaction(Pager *pPager){
   }
 
   if( !pPager->exclusiveMode ){
-    rc2 = sqlite3OsUnlock(pPager->fd, SHARED_LOCK);
+    rc2 = osUnlock(pPager->fd, SHARED_LOCK);
     pPager->state = PAGER_SHARED;
   }else if( pPager->state==PAGER_SYNCED ){
     pPager->state = PAGER_EXCLUSIVE;
@@ -1318,7 +1328,7 @@ static void pager_truncate_cache(Pager *pPager);
 */
 static int pager_truncate(Pager *pPager, int nPage){
   int rc = SQLITE_OK;
-  if( pPager->state>=PAGER_EXCLUSIVE ){
+  if( pPager->state>=PAGER_EXCLUSIVE && pPager->fd->pMethods ){
     rc = sqlite3OsTruncate(pPager->fd, pPager->pageSize*(i64)nPage);
   }
   if( rc==SQLITE_OK ){
@@ -1335,7 +1345,14 @@ static int pager_truncate(Pager *pPager, int nPage){
 ** by sqlite3OsSectorSize() and the pageSize.
 */
 static void setSectorSize(Pager *pPager){
+  assert(pPager->fd->pMethods||pPager->tempFile);
+  if( !pPager->tempFile ){
+    /* Sector size doesn't matter for temporary files. Also, the file
+    ** may not have been opened yet, in whcih case the OsSectorSize()
+    ** call will segfault.
+    */
     pPager->sectorSize = sqlite3OsSectorSize(pPager->fd);
+  }
   if( pPager->sectorSize<pPager->pageSize ){
     pPager->sectorSize = pPager->pageSize;
   }
@@ -1823,10 +1840,13 @@ int sqlite3PagerOpen(
       }
     }
   }else{
-    rc = sqlite3PagerOpentemp(pVfs, pPager->fd, pPager->zFilename);
+    /* If a temporary file is requested, it is not opened immediately.
-    if( rc==SQLITE_OK ){
+    ** In this case we accept the default page size and delay actually
+    ** opening the file until the first call to OsWrite().
+    */ 
+    /* rc = sqlite3PagerOpentemp(pVfs, pPager->fd, pPager->zFilename); */
     tempFile = 1;
-    }
+    pPager->state = PAGER_EXCLUSIVE;
   }
 
   if( pPager && rc==SQLITE_OK ){
@@ -1887,7 +1907,7 @@ int sqlite3PagerOpen(
   /* pPager->pFirstSynced = 0; */
   /* pPager->pLast = 0; */
   pPager->nExtra = FORCE_ALIGNMENT(nExtra);
-  assert(pPager->fd->pMethods||memDb);
+  assert(pPager->fd->pMethods||memDb||tempFile);
   if( !memDb ){
     setSectorSize(pPager);
   }
@@ -1999,7 +2019,8 @@ void enable_simulated_io_errors(void){
 int sqlite3PagerReadFileheader(Pager *pPager, int N, unsigned char *pDest){
   int rc = SQLITE_OK;
   memset(pDest, 0, N);
-  if( MEMDB==0 ){
+  assert(MEMDB||pPager->fd->pMethods||pPager->tempFile);
+  if( pPager->fd->pMethods ){
     IOTRACE(("DBHDR %p 0 %d\n", pPager, N))
     rc = sqlite3OsRead(pPager->fd, pDest, N, 0);
     if( rc==SQLITE_IOERR_SHORT_READ ){
@@ -2019,7 +2040,7 @@ int sqlite3PagerReadFileheader(Pager *pPager, int N, unsigned char *pDest){
 ** file is 4096 bytes, 5 is returned instead of 4.
 */
 int sqlite3PagerPagecount(Pager *pPager){
-  i64 n;
+  i64 n = 0;
   int rc;
   assert( pPager!=0 );
   if( pPager->errCode ){
@@ -2028,7 +2049,9 @@ int sqlite3PagerPagecount(Pager *pPager){
   if( pPager->dbSize>=0 ){
     n = pPager->dbSize;
   } else {
-    if( (rc = sqlite3OsFileSize(pPager->fd, &n))!=SQLITE_OK ){
+    assert(pPager->fd->pMethods||pPager->tempFile);
+    if( (pPager->fd->pMethods)
+     && (rc = sqlite3OsFileSize(pPager->fd, &n))!=SQLITE_OK ){
       pager_error(pPager, rc);
       return 0;
     }
@@ -2570,6 +2593,14 @@ static int pager_write_pagelist(PgHdr *pList){
 
   pList = sort_pagelist(pList);
   while( pList ){
+
+    /* If the file has not yet been opened, open it now. */
+    if( !pPager->fd->pMethods ){
+      assert(pPager->tempFile);
+      rc = sqlite3PagerOpentemp(pPager->pVfs, pPager->fd, pPager->zFilename);
+      if( rc ) return rc;
+    }
+
     assert( pList->dirty );
     /* If there are dirty pages in the page cache with page numbers greater
     ** than Pager.dbSize, this means sqlite3PagerTruncate() was called to
@@ -2834,6 +2865,10 @@ static int readDbPage(Pager *pPager, PgHdr *pPg, Pgno pgno){
   int rc;
   i64 offset;
   assert( MEMDB==0 );
+  assert(pPager->fd->pMethods||pPager->tempFile);
+  if( !pPager->fd->pMethods ){
+    return SQLITE_IOERR_SHORT_READ;
+  }
   offset = (pgno-1)*(i64)pPager->pageSize;
   rc = sqlite3OsRead(pPager->fd, PGHDR_TO_DATA(pPg), pPager->pageSize, offset);
   PAGER_INCR(sqlite3_pager_readdb_count);

test/conflict.test

@@ -13,7 +13,7 @@
 # This file implements tests for the conflict resolution extension
 # to SQLite.
 #
-# $Id: conflict.test,v 1.29 2007/04/06 21:42:22 drh Exp $
+# $Id: conflict.test,v 1.30 2007/08/21 14:27:02 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -285,20 +285,23 @@ do_test conflict-6.0 {
 #   t3     Number of temporary files for tables
 #   t4     Number of temporary files for statement journals
 #
+# Update: Since temporary table files are now opened lazily, and none
+# of the following tests use large quantities of data, t3 is always 0.
+#
 foreach {i conf1 cmd t0 t1 t2 t3 t4} {
   1 {}       UPDATE                  1 {6 7 8 9}  1 0 1
-  2 REPLACE  UPDATE                  0 {7 6 9}    1 1 0
+  2 REPLACE  UPDATE                  0 {7 6 9}    1 0 0
-  3 IGNORE   UPDATE                  0 {6 7 3 9}  1 1 0
+  3 IGNORE   UPDATE                  0 {6 7 3 9}  1 0 0
   4 FAIL     UPDATE                  1 {6 7 3 4}  1 0 0
   5 ABORT    UPDATE                  1 {1 2 3 4}  1 0 1
   6 ROLLBACK UPDATE                  1 {1 2 3 4}  0 0 0
-  7 REPLACE  {UPDATE OR IGNORE}      0 {6 7 3 9}  1 1 0
+  7 REPLACE  {UPDATE OR IGNORE}      0 {6 7 3 9}  1 0 0
-  8 IGNORE   {UPDATE OR REPLACE}     0 {7 6 9}    1 1 0
+  8 IGNORE   {UPDATE OR REPLACE}     0 {7 6 9}    1 0 0
-  9 FAIL     {UPDATE OR IGNORE}      0 {6 7 3 9}  1 1 0
+  9 FAIL     {UPDATE OR IGNORE}      0 {6 7 3 9}  1 0 0
- 10 ABORT    {UPDATE OR REPLACE}     0 {7 6 9}    1 1 0
+ 10 ABORT    {UPDATE OR REPLACE}     0 {7 6 9}    1 0 0
- 11 ROLLBACK {UPDATE OR IGNORE}      0 {6 7 3 9}  1 1 0
+ 11 ROLLBACK {UPDATE OR IGNORE}      0 {6 7 3 9}  1 0 0
- 12 {}       {UPDATE OR IGNORE}      0 {6 7 3 9}  1 1 0
+ 12 {}       {UPDATE OR IGNORE}      0 {6 7 3 9}  1 0 0
- 13 {}       {UPDATE OR REPLACE}     0 {7 6 9}    1 1 0
+ 13 {}       {UPDATE OR REPLACE}     0 {7 6 9}    1 0 0
  14 {}       {UPDATE OR FAIL}        1 {6 7 3 4}  1 0 0
  15 {}       {UPDATE OR ABORT}       1 {1 2 3 4}  1 0 1
  16 {}       {UPDATE OR ROLLBACK}    1 {1 2 3 4}  0 0 0