Go back to allocating each page and its header with a single memory

allocation.  This undoes the change of (4409). (CVS 4495)

FossilOrigin-Name: f56c9884be796dee3f267aca6021eb1846d8527c

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\smutex\sleak\sin\sthe\snew\smalloc-free\smemory\sallocator.\s(CVS\s4494)
-D 2007-10-20T12:34:01
+C Go\sback\sto\sallocating\seach\spage\sand\sits\sheader\swith\sa\ssingle\smemory\nallocation.\s\sThis\sundoes\sthe\schange\sof\s(4409).\s(CVS\s4495)
+D 2007-10-20T13:17:55
 F Makefile.in 30c7e3ba426ddb253b8ef037d1873425da6009a8
 F Makefile.linux-gcc 65241babba6faf1152bf86574477baab19190499
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -121,7 +121,7 @@ F src/os_unix.c 308bd8ad6977f66f608228cccaecc4cbc1a24693
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c fe8f2d8fc3a010a2e9d4a0acbdcf4981522cac7b
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c 0a92a08192785af79547b017cda45eb683b22552
+F src/pager.c a464ba8e6001573556420be0afc178a370717f64
 F src/pager.h d783e7f184afdc33adff37ba58d4e029bd8793b3
 F src/parse.y 2d2ce439dc6184621fb0b86f4fc5aca7f391a590
 F src/pragma.c 363e548dafb52327face8d99757ab56a7b1c1b26
@@ -582,7 +582,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 8487ca82fade60b9fa63abf74e10f6ebcb48b98e
-R 90ba9f4c15dca4497d400480c35485e4
+P 30f014d3d0231a668c40508ff4a6b90ce622c857
+R 353b5c52c9c15c7259d8c65cac3000a2
 U drh
-Z ea0e251b46a75fe3eb6d2bdbc7463d99
+Z 00b4c63daba6680a8c5aa4fee0ee068a

manifest.uuid

@@ -1 +1 @@
-30f014d3d0231a668c40508ff4a6b90ce622c857
+f56c9884be796dee3f267aca6021eb1846d8527c

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.392 2007/10/03 15:22:26 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.393 2007/10/20 13:17:55 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1227,7 +1227,6 @@ static void pager_reset(Pager *pPager){
     PAGER_INCR(sqlite3_pager_pgfree_count);
     pNext = pPg->pNextAll;
     lruListRemove(pPg);
-    sqlite3_free(pPg->pData);
     sqlite3_free(pPg);
   }
   assert(pPager->lru.pFirst==0);
@@ -2533,7 +2532,6 @@ static void pager_truncate_cache(Pager *pPager){
       PAGER_INCR(sqlite3_pager_pgfree_count);
       unlinkPage(pPg);
       makeClean(pPg);
-      sqlite3_free(pPg->pData);
       sqlite3_free(pPg);
       pPager->nPage--;
     }
@@ -3197,7 +3195,6 @@ int sqlite3PagerReleaseMemory(int nReq){
       );
       IOTRACE(("PGFREE %p %d *\n", pPager, pPg->pgno));
       PAGER_INCR(sqlite3_pager_pgfree_count);
-      sqlite3_free(pPg->pData);
       sqlite3_free(pPg);
       pPager->nPage--;
     }else{
@@ -3460,7 +3457,7 @@ static int pagerSharedLock(Pager *pPager){
 static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
   int rc = SQLITE_OK;
   PgHdr *pPg;
-  void *pData;
+  int nByteHdr;
 
   /* Create a new PgHdr if any of the four conditions defined 
   ** above are met: */
@@ -3478,25 +3475,16 @@ static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
       }
     }
     pagerLeave(pPager);
-    pPg = sqlite3_malloc( sizeof(*pPg) + sizeof(u32) + pPager->nExtra
-                            + MEMDB*sizeof(PgHistory) );
-    if( pPg ){
-      pData = sqlite3_malloc( pPager->pageSize );
-      if( pData==0 ){
-        sqlite3_free(pPg);
-        pPg = 0;
-      }
-    }
+    nByteHdr = sizeof(*pPg) + sizeof(u32) + pPager->nExtra
+              + MEMDB*sizeof(PgHistory);
+    pPg = sqlite3_malloc( nByteHdr + pPager->pageSize );
     pagerEnter(pPager);
     if( pPg==0 ){
       rc = SQLITE_NOMEM;
       goto pager_allocate_out;
     }
-    memset(pPg, 0, sizeof(*pPg));
-    if( MEMDB ){
-      memset(PGHDR_TO_HIST(pPg, pPager), 0, sizeof(PgHistory));
-    }
-    pPg->pData = pData;
+    memset(pPg, 0, nByteHdr);
+    pPg->pData = (void*)(nByteHdr + (char*)pPg);
     pPg->pPager = pPager;
     pPg->pNextAll = pPager->pAll;
     pPager->pAll = pPg;