From: drh <drh@noemail.net>
Date: Wed, 23 Jun 2010 15:04:27 +0000 (+0000)
Subject: Simplifications to the pager_delmaster() implementation.
X-Git-Tag: version-3.7.2~247
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=a64febe1d23cac22ae8163c3bba46fbeef75fed7;p=thirdparty%2Fsqlite.git

Simplifications to the pager_delmaster() implementation.

FossilOrigin-Name: 8bfbdec647d29f0eb103ba7deb9116c44193f2e1
---

diff --git a/manifest b/manifest
index eff616811c..5bdc71722c 100644
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Disable\scode\sused\sonly\sby\sthe\scodec\swhen\sthe\scodec\sis\snot\sdeployed.
-D 2010-06-22T21:15:50
+C Simplifications\sto\sthe\spager_delmaster()\simplementation.
+D 2010-06-23T15:04:27
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in a5cad1f8f3e021356bfcc6c77dc16f6f1952bbc3
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -159,7 +159,7 @@ F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 665876d5eec7585226b0a1cf5e18098de2b2da19
 F src/os_unix.c 5231a75a3799872b1250bc70c0e6a1a5960bc865
 F src/os_win.c 73608839342de32280cb378d3c2fc85a5dd80bd2
-F src/pager.c 54719676081c6ffe48d333698c3fc4ec2cb184f3
+F src/pager.c f16d9f21c4c715ed3d8e6318f50036c93afae224
 F src/pager.h 879fdde5a102d2f21a3135d6f647530b21c2796c
 F src/parse.y ace5c7a125d9f2a410e431ee3209034105045f7e
 F src/pcache.c 1e9aa2dbc0845b52e1b51cc39753b6d1e041cb07
@@ -828,14 +828,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 393741eba353d5d242b8e3c96db3ea2b92228036
-R a98e0c1a959f76ef6bea94ee96e38ea8
+P 2c90276e340aa19d78d2e33c9f759f8eda0b82a3
+R bf609900200a14a42c360ea6940da933
 U drh
-Z c41882a67704e43aa1f9a5f9eff0a10d
+Z 1f39d78260e4e9f5fdcb6d571e456a29
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.6 (GNU/Linux)
 
-iD8DBQFMISgJoxKgR168RlERAqKAAJ4lHvGOXiCW0m/XZuzHlM4sH/bgLQCbB6c7
-O+DRDmTpPwGjNikY9THJ3Z0=
-=I8ep
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+qi6cM1OvlcvjNuhNM77GvtA=
+=aMLO
 -----END PGP SIGNATURE-----
diff --git a/manifest.uuid b/manifest.uuid
index a6b08e2e04..8f81b129b8 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2c90276e340aa19d78d2e33c9f759f8eda0b82a3
\ No newline at end of file
+8bfbdec647d29f0eb103ba7deb9116c44193f2e1
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index a0902a8623..78027b0ac9 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -1796,6 +1796,9 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   sqlite3_file *pJournal;   /* Malloc'd child-journal file descriptor */
   char *zMasterJournal = 0; /* Contents of master journal file */
   i64 nMasterJournal;       /* Size of master journal file */
+  char *zJournal;           /* Pointer to one journal within MJ file */
+  char *zMasterPtr;         /* Space to hold MJ filename from a journal file */
+  int nMasterPtr;           /* Amount of space allocated to zMasterPtr[] */
 
   /* Allocate space for both the pJournal and pMaster file descriptors.
   ** If successful, open the master journal file for reading.
@@ -1810,69 +1813,63 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   }
   if( rc!=SQLITE_OK ) goto delmaster_out;
 
+  /* Load the entire master journal file into space obtained from
+  ** sqlite3_malloc() and pointed to by zMasterJournal.   Also obtain
+  ** sufficient space (in zMasterPtr) to hold the names of master
+  ** journal files extracted from regular rollback-journals.
+  */
   rc = sqlite3OsFileSize(pMaster, &nMasterJournal);
   if( rc!=SQLITE_OK ) goto delmaster_out;
+  nMasterPtr = pVfs->mxPathname+1;
+  zMasterJournal = sqlite3Malloc((int)nMasterJournal + nMasterPtr + 1);
+  if( !zMasterJournal ){
+    rc = SQLITE_NOMEM;
+    goto delmaster_out;
+  }
+  zMasterPtr = &zMasterJournal[nMasterJournal+1];
+  rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);
+  if( rc!=SQLITE_OK ) goto delmaster_out;
+  zMasterJournal[nMasterJournal] = 0;
 
-  if( nMasterJournal>0 ){
-    char *zJournal;
-    char *zMasterPtr = 0;
-    int nMasterPtr = pVfs->mxPathname+1;
-
-    /* Load the entire master journal file into space obtained from
-    ** sqlite3_malloc() and pointed to by zMasterJournal. 
-    */
-    zMasterJournal = sqlite3Malloc((int)nMasterJournal + nMasterPtr + 1);
-    if( !zMasterJournal ){
-      rc = SQLITE_NOMEM;
+  zJournal = zMasterJournal;
+  while( (zJournal-zMasterJournal)<nMasterJournal ){
+    int exists;
+    rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
+    if( rc!=SQLITE_OK ){
       goto delmaster_out;
     }
-    zMasterPtr = &zMasterJournal[nMasterJournal+1];
-    rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);
-    if( rc!=SQLITE_OK ) goto delmaster_out;
-    zMasterJournal[nMasterJournal] = 0;
-
-    zJournal = zMasterJournal;
-    while( (zJournal-zMasterJournal)<nMasterJournal ){
-      int exists;
-      rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
+    if( exists ){
+      /* One of the journals pointed to by the master journal exists.
+      ** Open it and check if it points at the master journal. If
+      ** so, return without deleting the master journal file.
+      */
+      int c;
+      int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
+      rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
       if( rc!=SQLITE_OK ){
         goto delmaster_out;
       }
-      if( exists ){
-        /* One of the journals pointed to by the master journal exists.
-        ** Open it and check if it points at the master journal. If
-        ** so, return without deleting the master journal file.
-        */
-        int c;
-        int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
-        rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
-        if( rc!=SQLITE_OK ){
-          goto delmaster_out;
-        }
 
-        rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
-        sqlite3OsClose(pJournal);
-        if( rc!=SQLITE_OK ){
-          goto delmaster_out;
-        }
+      rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
+      sqlite3OsClose(pJournal);
+      if( rc!=SQLITE_OK ){
+        goto delmaster_out;
+      }
 
-        c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
-        if( c ){
-          /* We have a match. Do not delete the master journal file. */
-          goto delmaster_out;
-        }
+      c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
+      if( c ){
+        /* We have a match. Do not delete the master journal file. */
+        goto delmaster_out;
       }
-      zJournal += (sqlite3Strlen30(zJournal)+1);
     }
+    zJournal += (sqlite3Strlen30(zJournal)+1);
   }
  
   sqlite3OsClose(pMaster);
   rc = sqlite3OsDelete(pVfs, zMaster, 0);
 
 delmaster_out:
-  if( zMasterJournal ){
-    sqlite3_free(zMasterJournal);
-  }  
+  sqlite3_free(zMasterJournal);
   if( pMaster ){
     sqlite3OsClose(pMaster);
     assert( !isOpen(pJournal) );