Auto-vacuum: Account for the page reserved for windows locking (PENDING_BYTE). (CVS 2076)

FossilOrigin-Name: d6335698696c7b651bbc436c5177d87eb57a8934

manifest

@@ -1,5 +1,5 @@
-C Reindex\stests\sadded\sand\sbugs\sfixed.\s(CVS\s2075)
+C Auto-vacuum:\sAccount\sfor\sthe\spage\sreserved\sfor\swindows\slocking\s(PENDING_BYTE).\s(CVS\s2076)
-D 2004-11-07T13:01:50
+D 2004-11-08T07:13:14
 F Makefile.in c4d2416860f472a1e3393714d0372074197565df
 F Makefile.linux-gcc a9e5a0d309fa7c38e7c14d3ecf7690879d3a5457
 F README a01693e454a00cc117967e3f9fdab2d4d52e9bc1
@@ -29,7 +29,7 @@ F sqlite3.def dbaeb20c153e1d366e8f421b55a573f5dfc00863
 F sqlite3.pc.in 985b9bf34192a549d7d370e0f0b6b34a4f61369a
 F src/attach.c e49d09dad9f5f9fb10b4b0c1be5a70ae4c45e689
 F src/auth.c 3b81f2a42f48a62c2c9c9b0eda31a157c681edea
-F src/btree.c 8ae13efe790fc462ee590ba96e1940f4c943fe19
+F src/btree.c e88077ac041e153ba130488e5cef9475dd656966
 F src/btree.h 861e40b759a195ba63819740e484390012cf81ab
 F src/build.c f01c2f9b3ad334a301e97ee4f299c36228ead110
 F src/date.c 34bdb0082db7ec2a83ef00063f7b44e61ee19dad
@@ -42,7 +42,7 @@ F src/insert.c 3fd6e00c9f62ad14daa94c75ae9971c32119f97e
 F src/legacy.c d58ea507bce885298a2c8c3cbb0f4bff5d47830b
 F src/main.c ba1b26f03af4b7f8be3394748123dd671b9ea147
 F src/md5.c 7ae1c39044b95de2f62e066f47bb1deb880a1070
-F src/os.h 5834a404b7c8318dc1928c9fc0137a65c9c0416c
+F src/os.h 38258df2db895499b6e2957dbf17f25e0df71667
 F src/os_common.h 0e7f428ba0a6c40a61bc56c4e96f493231301b73
 F src/os_mac.c 7367dab0c44ab0b2c4337e73ac6f6f97f171c2cb
 F src/os_mac.h 608fdf39eafa1ce25fc8cb223b8b0a073341d4da
@@ -52,7 +52,7 @@ F src/os_unix.c 5824b22ba41fe9d514ef9169aac1b5fde73af229
 F src/os_unix.h f3097815e041e82e24d92505e1ff61ba24172d13
 F src/os_win.c 9482dfc92f289b68205bb2c9315757c7e3946bfb
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c 0523c8a122f95b41008b87cae2cc1d368452dbfc
+F src/pager.c 942cbb9d1de5e198d26979f992eba1b4e527ac08
 F src/pager.h 9eba8c53dd91eae7f3f90743b2ee242da02a9862
 F src/parse.y 8456726833755ecd6dac9bcd8af205c8dc419d01
 F src/pragma.c 6a0ae7721e614c5a921e918ab5206d5e654f1a6f
@@ -253,7 +253,7 @@ F www/tclsqlite.tcl 560ecd6a916b320e59f2917317398f3d59b7cc25
 F www/vdbe.tcl 59288db1ac5c0616296b26dce071c36cb611dfe9
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl fdacb0ba2d39831e8a6240d05a490026ad4c4e4c
-P 081676e491760a45325e2349b177d6382faab9f5
+P ad433ec2b6bd34e33dfe119668f38fbb978e889d
-R 6630382fc7d25a2e7888b420a0d94622
+R f5ced09dda22d2b1aa5518cabc940350
-U drh
+U danielk1977
-Z 052f1c7409b37943337cd90fbf34df5d
+Z febc6549f1b02ac6b75a38defec39cf5

manifest.uuid

@@ -1 +1 @@
-ad433ec2b6bd34e33dfe119668f38fbb978e889d
+d6335698696c7b651bbc436c5177d87eb57a8934

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.213 2004/11/06 12:26:08 danielk1977 Exp $
+** $Id: btree.c,v 1.214 2004/11/08 07:13:14 danielk1977 Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -394,8 +394,13 @@ static void put4byte(unsigned char *p, u32 v){
 #define getVarint32  sqlite3GetVarint32
 #define putVarint    sqlite3PutVarint
 
-#ifndef SQLITE_OMIT_AUTOVACUUM
+/* The database page the PENDING_BYTE occupies. This page is never used.
+** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
+** should possibly be consolidated (presumably in pager.h).
+*/
+#define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)
 
+#ifndef SQLITE_OMIT_AUTOVACUUM
 /*
 ** These two macros define the location of the pointer-map entry for a 
 ** database page. The first argument to each is the page size used 
@@ -408,11 +413,11 @@ static void put4byte(unsigned char *p, u32 v){
 **
 ** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
 ** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be
-** used to test if pgno is a pointer-map page.
+** used to test if pgno is a pointer-map page. PTRMAP_ISPAGE implements
+** this test.
 */
 #define PTRMAP_PAGENO(pgsz, pgno) (((pgno-2)/(pgsz/5+1))*(pgsz/5+1)+2)
 #define PTRMAP_PTROFFSET(pgsz, pgno) (((pgno-2)%(pgsz/5+1)-1)*5)
-
 #define PTRMAP_ISPAGE(pgsz, pgno) (PTRMAP_PAGENO(pgsz,pgno)==pgno)
 
 /*
@@ -459,6 +464,7 @@ static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
   int offset;     /* Offset in pointer map page */
   int rc;
 
+  assert( key!=0 );
   iPtrmap = PTRMAP_PAGENO(pBt->pageSize, key);
   rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
   if( rc!=SQLITE_OK ){
@@ -1755,6 +1761,12 @@ static int autoVacuumCommit(Btree *pBt, Pgno *nTrunc){
   origSize = sqlite3pager_pagecount(pPager);
   nPtrMap = (nFreeList-origSize+PTRMAP_PAGENO(pgsz, origSize)+pgsz/5)/(pgsz/5);
   finSize = origSize - nFreeList - nPtrMap;
+  if( origSize>PENDING_BYTE_PAGE(pBt) && finSize<=PENDING_BYTE_PAGE(pBt) ){
+    finSize--;
+    if( PTRMAP_ISPAGE(pBt->pageSize, finSize) ){
+      finSize--;
+    }
+  }
   TRACE(("AUTOVACUUM: Begin (db size %d->%d)\n", origSize, finSize));
 
   /* Variable 'finSize' will be the size of the file in pages after
@@ -1764,14 +1776,17 @@ static int autoVacuumCommit(Btree *pBt, Pgno *nTrunc){
   ** to a free page earlier in the file (somewhere before finSize).
   */
   for( iDbPage=finSize+1; iDbPage<=origSize; iDbPage++ ){
+    /* If iDbPage is a pointer map page, or the pending-byte page, skip it. */
+    if( PTRMAP_ISPAGE(pgsz, iDbPage) || iDbPage==PENDING_BYTE_PAGE(pBt) ){
+      continue;
+    }
+
     rc = ptrmapGet(pBt, iDbPage, &eType, &iPtrPage);
     if( rc!=SQLITE_OK ) goto autovacuum_out;
     assert( eType!=PTRMAP_ROOTPAGE );
 
-    /* If iDbPage is a free or pointer map page, do not swap it.
+    /* If iDbPage is free, do not swap it.  */
-    ** TODO: Instead, make sure the page is in the journal file.
+    if( eType==PTRMAP_FREEPAGE ){
-    */
-    if( eType==PTRMAP_FREEPAGE || PTRMAP_ISPAGE(pgsz, iDbPage) ){
       continue;
     }
     rc = getPage(pBt, iDbPage, &pDbMemPage);
@@ -3052,15 +3067,19 @@ static int allocatePage(
       ** becomes a new pointer-map page, the second is used by the caller.
       */
       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", *pPgno));
+      assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
       (*pPgno)++;
     }
 #endif
 
+    assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
     rc = getPage(pBt, *pPgno, ppPage);
     if( rc ) return rc;
     rc = sqlite3pager_write((*ppPage)->aData);
     TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
   }
+
+  assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
   return rc;
 }
 
@@ -4383,8 +4402,11 @@ int sqlite3BtreeCreateTable(Btree *pBt, int *piTable, int flags){
     if( rc!=SQLITE_OK ) return rc;
     pgnoRoot++;
 
-    /* The new root-page may not be allocated on a pointer-map page. */
+    /* The new root-page may not be allocated on a pointer-map page, or the
-    if( pgnoRoot==PTRMAP_PAGENO(pBt->pageSize, pgnoRoot) ){
+    ** PENDING_BYTE page.
+    */
+    if( pgnoRoot==PTRMAP_PAGENO(pBt->pageSize, pgnoRoot) ||
+        pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
       pgnoRoot++;
     }
     assert( pgnoRoot>=3 );
@@ -4616,10 +4638,20 @@ int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
         *piMoved = maxRootPgno;
       }
 
+      /* Set the new 'max-root-page' value in the database header. This
+      ** is the old value less one, less one more if that happens to
+      ** be a root-page number, less one again if that is the
+      ** PENDING_BYTE_PAGE.
+      */
       maxRootPgno--;
+      if( maxRootPgno==PENDING_BYTE_PAGE(pBt) ){
+        maxRootPgno--;
+      }
       if( maxRootPgno==PTRMAP_PAGENO(pBt->pageSize, maxRootPgno) ){
         maxRootPgno--;
       }
+      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );
+
       rc = sqlite3BtreeUpdateMeta(pBt, 4, maxRootPgno);
     }else{
       rc = freePage(pPage);
@@ -4655,9 +4687,9 @@ int sqlite3BtreeGetMeta(Btree *pBt, int idx, u32 *pMeta){
   *pMeta = get4byte(&pP1[36 + idx*4]);
   sqlite3pager_unref(pP1);
 
-  /* If autovacuumed is disabled in the implementation but we are
+  /* If autovacuumed is disabled in this build but we are trying to 
-  ** trying to access an autovacuumed database, then make the
+  ** access an autovacuumed database, then make the database readonly. 
-  ** database readonly. */
+  */
 #ifdef SQLITE_OMIT_AUTOVACUUM
   if( idx==4 && *pMeta>0 ) pBt->readOnly = 1;
 #endif

src/os.h

@@ -162,7 +162,7 @@
 **
 */
 #define PENDING_BYTE      0x40000000  /* First byte past the 1GB boundary */
-/* #define PENDING_BYTE     0x5400   // Page 20 - for testing */
+/* #define PENDING_BYTE     0x5400   // Page 22 - for testing */
 #define RESERVED_BYTE     (PENDING_BYTE+1)
 #define SHARED_FIRST      (PENDING_BYTE+2)
 #define SHARED_SIZE       510

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.174 2004/11/06 12:26:08 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.175 2004/11/08 07:13:14 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -34,13 +34,25 @@
 #define TRACE2(X,Y)     sqlite3DebugPrintf(X,Y)
 #define TRACE3(X,Y,Z)   sqlite3DebugPrintf(X,Y,Z)
 #define TRACE4(X,Y,Z,W) sqlite3DebugPrintf(X,Y,Z,W)
+#define TRACE5(X,Y,Z,W,V) sqlite3DebugPrintf(X,Y,Z,W, V)
 #else
 #define TRACE1(X)
 #define TRACE2(X,Y)
 #define TRACE3(X,Y,Z)
 #define TRACE4(X,Y,Z,W)
+#define TRACE5(X,Y,Z,W,V)
 #endif
 
+/*
+** The following two macros are used within the TRACEX() macros above
+** to print out file-descriptors. They are required so that tracing
+** can be turned on when using both the regular os_unix.c and os_test.c
+** backends.
+**
+** PAGERID() takes a pointer to a Pager struct as it's argument. The
+** associated file-descriptor is returned. FILEHANDLEID() takes an OsFile
+** struct as it's argument.
+*/
 #ifdef OS_TEST
 #define PAGERID(p) (p->fd->fd.h)
 #define FILEHANDLEID(fd) (fd->fd.h)
@@ -339,7 +351,8 @@ static const unsigned char aJournalMagic[] = {
 ** is devoted to storing a master journal name - there are no more pages to
 ** roll back. See comments for function writeMasterJournal() for details.
 */
-#define PAGER_MJ_PGNO(x) (PENDING_BYTE/((x)->pageSize))
+/* #define PAGER_MJ_PGNO(x) (PENDING_BYTE/((x)->pageSize)) */
+#define PAGER_MJ_PGNO(x) ((PENDING_BYTE/((x)->pageSize))+1)
 
 /*
 ** Enable reference count tracking (for debugging) here:
@@ -3271,7 +3284,6 @@ sync_exit:
 }
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
-
 /*
 ** Move the page identified by pData to location pgno in the file. 
 **
@@ -3295,13 +3307,16 @@ int sqlite3pager_movepage(Pager *pPager, void *pData, Pgno pgno){
   assert( !pPager->stmtInUse );
   assert( pPg->nRef>0 );
 
-  TRACE4("MOVE %d page %d moves to %d\n", PAGERID(pPager), pPg->pgno, pgno);
+  TRACE5("MOVE %d page %d (needSync=%d) moves to %d\n", 
+      PAGERID(pPager), pPg->pgno, pPg->needSync, pgno);
 
   /* Unlink pPg from it's hash-chain */
   unlinkHashChain(pPager, pPg);
 
   /* If the cache contains a page with page-number pgno, remove it
-  ** from it's hash chain.
+  ** from it's hash chain. Also, if the PgHdr.needSync was set for 
+  ** page pgno before the 'move' operation, it needs to be retained 
+  ** for the page moved there.
   */
   pPgOld = pager_lookup(pPager, pgno);
   if( pPgOld ){