Continuing work on the new memory allocation subsystem.

Added routines for temporary memory allocation.  Right the btree
balance mechanism to only do one temporary allocation at a time. (CVS 5220)

FossilOrigin-Name: 65fe7b62cfe7d11cd667681a64c96fe7b2fe5685

manifest

@@ -1,5 +1,5 @@
-C Continuing\sprogress\son\sthe\snew\smemory\sallocation\ssubsystem.\s\sAdded\sthe\nsqlite3_mem_methods\sstructure\sfor\sdefining\snew\smemory\sallocators\sat\nrun-time.\s(CVS\s5219)
+C Continuing\swork\son\sthe\snew\smemory\sallocation\ssubsystem.\nAdded\sroutines\sfor\stemporary\smemory\sallocation.\s\sRight\sthe\sbtree\nbalance\smechanism\sto\sonly\sdo\sone\stemporary\sallocation\sat\sa\stime.\s(CVS\s5220)
-D 2008-06-14T16:56:22
+D 2008-06-15T02:51:47
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in dc5608df93faf4406cfd7a1c8ed9ab93d8bfbfd5
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -92,60 +92,60 @@ F sqlite3.def a1be7b9a4b8b51ac41c6ff6e8e44a14ef66b338b
 F sqlite3.pc.in 32b8a014799c2028c8e0c9cc5659718262fc493f
 F src/alter.c cc38b9e2a8cf19428f64e5da7ec4da35b7c02779
 F src/analyze.c 9ee63497ee720728abe630d169ab91323ac7519c
-F src/attach.c 496cc628b2e8c4d8db99d7c136761fcbebd8420b
+F src/attach.c b18ba42c77f7d3941f5d23d2ca20fa1d841a4e91
 F src/auth.c c8b2ab5c8bad4bd90ed7c294694f48269162c627
 F src/bitvec.c ab50c4b8c6a899dae499f5a805eebe4223c78269
 F src/btmutex.c 483ced3c52205b04b97df69161fadbf87f4f1ea2
-F src/btree.c 1f4a3f8307b04c98ce250705b95555f820e857b2
+F src/btree.c b374c2ba457f442371aa92b065d1ba698cdee1dc
 F src/btree.h b1bd7e0b8c2e33658aaf447cb0d1d94f74664b6b
-F src/btreeInt.h dc04ee33d8eb84714b2acdf81336fbbf6e764530
+F src/btreeInt.h 02325f04758dba0fcd0c08ac55cd9b189dad61a5
-F src/build.c a52d9d51341444a2131e3431608f245db80d9591
+F src/build.c 88cc5501a87f72d0538b040001d88d31f994edea
 F src/callback.c 77b302b0d41468dcda78c70e706e5b84577f0fa0
 F src/complete.c cb14e06dbe79dee031031f0d9e686ff306afe07c
-F src/date.c 76a5ba94772346efedf0c412c47e67891bbb266c
+F src/date.c bbc4114d1b946d6a94d060bc5b9edce7142c6086
 F src/delete.c d3fc5987f2eb88f7b9549d58a5dfea079a83fe8b
 F src/expr.c ecb3b23d3543427cba3e2ac12a6c6ae4bb20d39b
 F src/fault.c 1f6177188edb00641673e462f3fab8cba9f7422b
-F src/func.c 77a910a1ca7613d291fd0b5cba3be14c02f0dce0
+F src/func.c 6ebd44016c5a6c6d5dd9fe4cbbef2bd517313d0d
 F src/global.c 2304cfa3288763bd2fed10caf8c6fbaa2b383f4e
-F src/hash.c fd8cb06fb54c2fe7d48c9195792059a2e5be8b70
+F src/hash.c 283864c1adf546d4f0a6ee3694b62beeda8fbd35
 F src/hash.h 031cd9f915aff27e12262cb9eb570ac1b8326b53
 F src/hwtime.h 745961687a65ef8918cd551c02e5ccb4b8e772de
 F src/insert.c c2ead6c36566de8e3f130e7ab1431723a269d5d7
 F src/journal.c cffd2cd214e58c0e99c3ff632b3bee6c7cbb260e
-F src/legacy.c 8f5a2b25d9673b4004287cf2bf51dbf7d0738406
+F src/legacy.c 3626c71fb70912abec9a4312beba753a9ce800df
 F src/loadext.c f99a75534a53e281fa2461239ee4a4b4bf6ad564
 F src/main.c 4540ec2c0ba99a0dcb8bd114f733007958c6258e
-F src/malloc.c ed5c36588992e63ce5dccdfeb3c8071b8fb34e17
+F src/malloc.c c5bdf8967df9acc9765ed1b55c0c0eba9fe9494c
 F src/md5.c 008216bbb5d34c6fbab5357aa68575ad8a31516a
-F src/mem1.c 9ac005ab606a58ffe32e40edd7526375be82a008
+F src/mem1.c c8e07e9e6620b1aabf9bdefd19dee93831f67733
-F src/mem2.c 10df776854bee610d5228e6184aaf3bd19f6e542
+F src/mem2.c 53d29d8275753e05676536c5db8f4867a622b31c
 F src/mem3.c 617c2e2a72a10ecc5c01af14efc8c2596d2c2e87
 F src/mem4.c 45c328ec6dcb7e8d319cb383615b5fe547ca5409
 F src/mem5.c 3d2ff00c6e3bc37f5d82cd82e1a123b246fb7b39
-F src/mutex.c 639881f679d75b30813536ddf9224154321c31fb
+F src/mutex.c 20f6ec9e2d85e257cae9e2ecc40a6769fad9e9e7
-F src/mutex.h 91292a8351b5844f7d622b0da83df4e651a8f40b
+F src/mutex.h b9b9baf7050f3bb1c723e1d22088a704783a2927
 F src/mutex_os2.c b8c1231319e966875f251a7ec137bea353546b87
 F src/mutex_unix.c 28588d08a2221623d66655e536880003fd5234d6
 F src/mutex_w32.c 36fbcf9f50bf0cd9be2c106cd69e5f59021402be
-F src/os.c 4f253152aefa4ba54ac7e2dc389a503862a9016c
+F src/os.c cf7e09d4215f35fc8269f0fa99f03fd2c2978658
 F src/os.h c9a7f94e80193fd4cf27f5c5698eb56753f1b05a
 F src/os_common.h 24525d8b7bce66c374dfc1810a6c9043f3359b60
 F src/os_os2.c 9f74147f1899793a106827f6bc770363ec377912
 F src/os_unix.c dd4a7b19ec00869764c389560c3faf566cf98a71
 F src/os_win.c 0b90d9a1ce18bfd2a5f3c4a6bdb13ec369c805a9
-F src/pager.c be98ceeb55bbcda9251c1a846d28c3d323885708
+F src/pager.c 5599fb3ebb63a60ecb44a18a594b371484a7e128
 F src/pager.h 6aa3050a3c684475a5a9dbad5ff1cebad612acba
 F src/parse.y 8c2c3145eebe1964eb279cb3c4e502eae28bb0fa
 F src/pragma.c 70e7c865dce85fdf9df81848af2169009a56ed08
-F src/prepare.c cbc9301aba1d0fc3d05fae576f2eb667c189cb36
+F src/prepare.c 3c19149e75fbf3b08471a389f064da7302cad9c5
-F src/printf.c f2d4f6c5b0ec24b643e85fe60258adad8b1f6acc
+F src/printf.c ff67198b0deee15b4415149880b8e3ab0a36705b
 F src/random.c 2b2db2de4ab491f5a14d3480466f8f4b5a5db74a
 F src/select.c 669687459e7d0193c89de06c5dbed55b4a41191c
 F src/shell.c a12ea645271b7876c8f080146f48e20b00d367ec
-F src/sqlite.h.in 0995188c694b36d041424e1b65b6e01d1802c70b
+F src/sqlite.h.in 9ff44542f18937a987f13dbc64f29f9a93b8b521
 F src/sqlite3ext.h faacd0e6a81aabee0861c6d7883c9172e74ef5b3
-F src/sqliteInt.h cd66968455ee85b1ffed33bb241cbf30fe760d32
+F src/sqliteInt.h bf561dab8a5155f25d3415fa056f570a731e2792
 F src/sqliteLimit.h f435e728c6b620ef7312814d660a81f9356eb5c8
 F src/table.c 1fa8f8113ac9cbc09ae4801c6d2a7f0af82c5822
 F src/tclsqlite.c c57e740e30bd6dda678796eed62c7f0e64689834
@@ -174,22 +174,22 @@ F src/test_schema.c e3f93725f7c5b2cff84a69dc4332040dfbc8f81a
 F src/test_server.c 7e579eb9bf6fbe9cc45e84e4c74d3d06d049a825
 F src/test_tclvar.c e99b975614735553fa1c43503d85b0dd988c0e77
 F src/test_thread.c e297dd41db0b249646e69f97d36ec13e56e8b730
-F src/tokenize.c d07c7482a59dd8e02f3f73e86ff55eccdc0d8f26
+F src/tokenize.c d39f0d6ce75ca9d0fa4041baec42b5e0411a74fc
 F src/trigger.c 1e751f8d5ceeb328d26bf1ccfb2de50653670d49
 F src/update.c 2d7143b9014e955509cc4f323f9a9584fb898f34
 F src/utf.c 8c94fa10efc78c2568d08d436acc59df4df7191b
 F src/util.c 920d6d5dfdf25f7b85d2093705d8716f9b387e3b
 F src/vacuum.c a5c289e561ed72283e97d2485491986bc7d684eb
-F src/vdbe.c 1936425c3455535a1a20e26a65c470fb009a1ed8
+F src/vdbe.c f6866986de706b98c2738040bc65907728650e8d
 F src/vdbe.h 1e3722d471739c2b213c6283b60373290e52f7ea
 F src/vdbeInt.h de321b2c02593e1420106634ed1f5a7d77ad35a7
 F src/vdbeapi.c 22b01ed175e4d4c613ee82cabc7a44a275641206
-F src/vdbeaux.c 08ec9a7d9dd47df2faa31d1bdf9595d88789f141
+F src/vdbeaux.c 34b9478ea0c8b41a6dbce6b1bb1c392c87bb0264
 F src/vdbeblob.c 554736781ee273a8089c776e96bdb53e66f57ce6
-F src/vdbefifo.c 1644a41c6366ff25a920df4ca675f12d3f559687
+F src/vdbefifo.c c46dae1194e4277bf007144d7e5b0c0b1c24f136
 F src/vdbemem.c a39a822e6ae61c4cab4a512df4a315888b206911
 F src/vtab.c ce9d19ca9053812a557010fd4be7e842f8ebba2d
-F src/where.c 6af9313bdcb6a1986402028864c4d4cf9879d873
+F src/where.c 5c4a999f6aed992131479bfaec9b874326d9963c
 F tclinstaller.tcl 4356d9d94d2b5ed5e68f9f0c80c4df3048dd7617
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/all.test d56a3ca8acdf761204aff0a2e7aa5eb8e11b31e6
@@ -594,7 +594,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P a03c5af115889f477e17187a198a7d2d40bc76bf
+P f00305f4cd2f487f660f34a21c1c24a0b37c7275
-R 7a7d2d9fd4f0061599821d0212d56ac9
+R 959050eddfb58749f141d64dc00b9d92
 U drh
-Z 3478c8b21bc53c2ad4322f8aef50d224
+Z a529f10f0af791d96bfc33f5cbab9f39

manifest.uuid

@@ -1 +1 @@
-f00305f4cd2f487f660f34a21c1c24a0b37c7275
+65fe7b62cfe7d11cd667681a64c96fe7b2fe5685

src/attach.c

@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file contains code used to implement the ATTACH and DETACH commands.
 **
-** $Id: attach.c,v 1.75 2008/04/17 17:02:01 drh Exp $
+** $Id: attach.c,v 1.76 2008/06/15 02:51:47 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -112,18 +112,12 @@ static void attachFunc(
   ** hash tables.
   */
   if( db->aDb==db->aDbStatic ){
-    aNew = sqlite3_malloc( sizeof(db->aDb[0])*3 );
+    aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
-    if( aNew==0 ){
+    if( aNew==0 ) return;
-      db->mallocFailed = 1;
-      return;
-    }
     memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
   }else{
-    aNew = sqlite3_realloc(db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
+    aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
-    if( aNew==0 ){
+    if( aNew==0 ) return;
-      db->mallocFailed = 1;
-      return;
-    } 
   }
   db->aDb = aNew;
   aNew = &db->aDb[db->nDb++];

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.463 2008/06/11 18:27:55 danielk1977 Exp $
+** $Id: btree.c,v 1.464 2008/06/15 02:51:47 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -300,7 +300,7 @@ static int saveCursorPosition(BtCursor *pCur){
   ** data.
   */
   if( rc==SQLITE_OK && 0==pCur->pPage->intKey){
-    void *pKey = sqlite3_malloc(pCur->nKey);
+    void *pKey = sqlite3Malloc(pCur->nKey);
     if( pKey ){
       rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
       if( rc==SQLITE_OK ){
@@ -1190,7 +1190,7 @@ int sqlite3BtreeOpen(
   ){
     if( sqlite3SharedCacheEnabled ){
       int nFullPathname = pVfs->mxPathname+1;
-      char *zFullPathname = (char *)sqlite3_malloc(nFullPathname);
+      char *zFullPathname = sqlite3Malloc(nFullPathname);
       sqlite3_mutex *mutexShared;
       p->sharable = 1;
       if( db ){
@@ -1267,9 +1267,6 @@ int sqlite3BtreeOpen(
          || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
       pBt->pageSize = 0;
       sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
-      pBt->maxEmbedFrac = 64;   /* 25% */
-      pBt->minEmbedFrac = 32;   /* 12.5% */
-      pBt->minLeafFrac = 32;    /* 12.5% */
 #ifndef SQLITE_OMIT_AUTOVACUUM
       /* If the magic name ":memory:" will create an in-memory database, then
       ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if
@@ -1285,9 +1282,6 @@ int sqlite3BtreeOpen(
       nReserve = 0;
     }else{
       nReserve = zDbHeader[20];
-      pBt->maxEmbedFrac = zDbHeader[21];
-      pBt->minEmbedFrac = zDbHeader[22];
-      pBt->minLeafFrac = zDbHeader[23];
       pBt->pageSizeFixed = 1;
 #ifndef SQLITE_OMIT_AUTOVACUUM
       pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);
@@ -1677,6 +1671,15 @@ static int lockBtree(BtShared *pBt){
     if( page1[19]>1 ){
       goto page1_init_failed;
     }
+
+    /* The maximum embedded fraction must be exactly 25%.  And the minimum
+    ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
+    ** The original design allowed these amounts to vary, but as of
+    ** version 3.6.0, we require them to be fixed.
+    */
+    if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
+      goto page1_init_failed;
+    }
     pageSize = get2byte(&page1[16]);
     if( ((pageSize-1)&pageSize)!=0 || pageSize<512 ||
         (SQLITE_MAX_PAGE_SIZE<32768 && pageSize>SQLITE_MAX_PAGE_SIZE)
@@ -1705,9 +1708,6 @@ static int lockBtree(BtShared *pBt){
     }
     pBt->pageSize = pageSize;
     pBt->usableSize = usableSize;
-    pBt->maxEmbedFrac = page1[21];
-    pBt->minEmbedFrac = page1[22];
-    pBt->minLeafFrac = page1[23];
 #ifndef SQLITE_OMIT_AUTOVACUUM
     pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);
     pBt->incrVacuum = (get4byte(&page1[36 + 7*4])?1:0);
@@ -1727,10 +1727,10 @@ static int lockBtree(BtShared *pBt){
   ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
   ** page pointer.
   */
-  pBt->maxLocal = (pBt->usableSize-12)*pBt->maxEmbedFrac/255 - 23;
+  pBt->maxLocal = (pBt->usableSize-12)*64/255 - 23;
-  pBt->minLocal = (pBt->usableSize-12)*pBt->minEmbedFrac/255 - 23;
+  pBt->minLocal = (pBt->usableSize-12)*32/255 - 23;
   pBt->maxLeaf = pBt->usableSize - 35;
-  pBt->minLeaf = (pBt->usableSize-12)*pBt->minLeafFrac/255 - 23;
+  pBt->minLeaf = (pBt->usableSize-12)*32/255 - 23;
   if( pBt->minLocal>pBt->maxLocal || pBt->maxLocal<0 ){
     goto page1_init_failed;
   }
@@ -1823,9 +1823,9 @@ static int newDatabase(BtShared *pBt){
   data[18] = 1;
   data[19] = 1;
   data[20] = pBt->pageSize - pBt->usableSize;
-  data[21] = pBt->maxEmbedFrac;
+  data[21] = 64;
-  data[22] = pBt->minEmbedFrac;
+  data[22] = 32;
-  data[23] = pBt->minLeafFrac;
+  data[23] = 32;
   memset(&data[24], 0, 100-24);
   zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
   pBt->pageSizeFixed = 1;
@@ -3719,14 +3719,14 @@ int sqlite3BtreeMoveto(
         if( available>=nCellKey ){
           c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey);
         }else{
-          pCellKey = sqlite3_malloc( nCellKey );
+          pCellKey = sqlite3TempMalloc( nCellKey );
           if( pCellKey==0 ){
             rc = SQLITE_NOMEM;
             goto moveto_finish;
           }
           rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey);
           c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pUnKey);
-          sqlite3_free(pCellKey);
+          sqlite3TempFree(pCellKey);
           if( rc ) goto moveto_finish;
         }
       }
@@ -4858,7 +4858,8 @@ static int balance_nonroot(MemPage *pPage){
   int usableSpace;             /* Bytes in pPage beyond the header */
   int pageFlags;               /* Value of pPage->aData[0] */
   int subtotal;                /* Subtotal of bytes in cells on one page */
-  int iSpace = 0;              /* First unused byte of aSpace[] */
+  int iSpace1 = 0;             /* First unused byte of aSpace1[] */
+  int iSpace2 = 0;             /* First unused byte of aSpace2[] */
   MemPage *apOld[NB];          /* pPage and up to two siblings */
   Pgno pgnoOld[NB];            /* Page numbers for each page in apOld[] */
   MemPage *apCopy[NB];         /* Private copies of apOld[] pages */
@@ -4869,8 +4870,9 @@ static int balance_nonroot(MemPage *pPage){
   int szNew[NB+2];             /* Combined size of cells place on i-th page */
   u8 **apCell = 0;             /* All cells begin balanced */
   u16 *szCell;                 /* Local size of all cells in apCell[] */
-  u8 *aCopy[NB];               /* Space for holding data of apCopy[] */
+  u8 *aCopy[NB];         /* Space for holding data of apCopy[] */
-  u8 *aSpace;                  /* Space to hold copies of dividers cells */
+  u8 *aSpace1;           /* Space for copies of dividers cells before balance */
+  u8 *aSpace2 = 0;       /* Space for overflow dividers cells after balance */
 #ifndef SQLITE_OMIT_AUTOVACUUM
   u8 *aFrom = 0;
 #endif
@@ -4988,11 +4990,11 @@ static int balance_nonroot(MemPage *pPage){
   /*
   ** Allocate space for memory structures
   */
-  apCell = sqlite3_malloc( 
+  apCell = sqlite3TempMalloc( 
        nMaxCells*sizeof(u8*)                       /* apCell */
      + nMaxCells*sizeof(u16)                       /* szCell */
      + (ROUND8(sizeof(MemPage))+pBt->pageSize)*NB  /* aCopy */
-     + pBt->pageSize*5                             /* aSpace */
+     + pBt->pageSize                               /* aSpace1 */
      + (ISAUTOVACUUM ? nMaxCells : 0)              /* aFrom */
   );
   if( apCell==0 ){
@@ -5006,13 +5008,18 @@ static int balance_nonroot(MemPage *pPage){
     aCopy[i] = &aCopy[i-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
     assert( ((aCopy[i] - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
   }
-  aSpace = &aCopy[NB-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
+  aSpace1 = &aCopy[NB-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
-  assert( ((aSpace - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
+  assert( ((aSpace1 - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
 #ifndef SQLITE_OMIT_AUTOVACUUM
   if( pBt->autoVacuum ){
-    aFrom = &aSpace[5*pBt->pageSize];
+    aFrom = &aSpace1[pBt->pageSize];
   }
 #endif
+  aSpace2 = sqlite3Malloc(pBt->pageSize);
+  if( aSpace2==0 ){
+    rc = SQLITE_NOMEM;
+    goto balance_cleanup;
+  }
   
   /*
   ** Make copies of the content of pPage and its siblings into aOld[].
@@ -5030,12 +5037,12 @@ static int balance_nonroot(MemPage *pPage){
   /*
   ** Load pointers to all cells on sibling pages and the divider cells
   ** into the local apCell[] array.  Make copies of the divider cells
-  ** into space obtained form aSpace[] and remove the the divider Cells
+  ** into space obtained form aSpace1[] and remove the the divider Cells
   ** from pParent.
   **
   ** If the siblings are on leaf pages, then the child pointers of the
   ** divider cells are stripped from the cells before they are copied
-  ** into aSpace[].  In this way, all cells in apCell[] are without
+  ** into aSpace1[].  In this way, all cells in apCell[] are without
   ** child pointers.  If siblings are not leaves, then all cell in
   ** apCell[] include child pointers.  Either way, all cells in apCell[]
   ** are alike.
@@ -5080,9 +5087,10 @@ static int balance_nonroot(MemPage *pPage){
         u8 *pTemp;
         assert( nCell<nMaxCells );
         szCell[nCell] = sz;
-        pTemp = &aSpace[iSpace];
+        pTemp = &aSpace1[iSpace1];
-        iSpace += sz;
+        iSpace1 += sz;
-        assert( iSpace<=pBt->pageSize*5 );
+        assert( sz<=pBt->pageSize/4 );
+        assert( iSpace1<=pBt->pageSize );
         memcpy(pTemp, apDiv[i], sz);
         apCell[nCell] = pTemp+leafCorrection;
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -5303,9 +5311,9 @@ static int balance_nonroot(MemPage *pPage){
       assert( j<nMaxCells );
       pCell = apCell[j];
       sz = szCell[j] + leafCorrection;
+      pTemp = &aSpace2[iSpace2];
       if( !pNew->leaf ){
         memcpy(&pNew->aData[8], pCell, 4);
-        pTemp = 0;
       }else if( leafData ){
         /* If the tree is a leaf-data tree, and the siblings are leaves, 
         ** then there is no divider cell in apCell[]. Instead, the divider 
@@ -5315,16 +5323,11 @@ static int balance_nonroot(MemPage *pPage){
         CellInfo info;
         j--;
         sqlite3BtreeParseCellPtr(pNew, apCell[j], &info);
-        pCell = &aSpace[iSpace];
+        pCell = pTemp;
         fillInCell(pParent, pCell, 0, info.nKey, 0, 0, 0, &sz);
-        iSpace += sz;
-        assert( iSpace<=pBt->pageSize*5 );
         pTemp = 0;
       }else{
         pCell -= 4;
-        pTemp = &aSpace[iSpace];
-        iSpace += sz;
-        assert( iSpace<=pBt->pageSize*5 );
         /* Obscure case for non-leaf-data trees: If the cell at pCell was
         ** previously stored on a leaf node, and its reported size was 4
         ** bytes, then it may actually be smaller than this 
@@ -5341,6 +5344,9 @@ static int balance_nonroot(MemPage *pPage){
           sz = cellSizePtr(pParent, pCell);
         }
       }
+      iSpace2 += sz;
+      assert( sz<=pBt->pageSize/4 );
+      assert( iSpace2<=pBt->pageSize );
       rc = insertCell(pParent, nxDiv, pCell, sz, pTemp, 4);
       if( rc!=SQLITE_OK ) goto balance_cleanup;
       put4byte(findOverflowCell(pParent,nxDiv), pNew->pgno);
@@ -5391,13 +5397,16 @@ static int balance_nonroot(MemPage *pPage){
   ** But the parent page will always be initialized.
   */
   assert( pParent->isInit );
+  sqlite3TempFree(apCell);
+  apCell = 0;
   rc = balance(pParent, 0);
   
   /*
   ** Cleanup before returning.
   */
 balance_cleanup:
-  sqlite3_free(apCell);
+  sqlite3_free(aSpace2);
+  sqlite3TempFree(apCell);
   for(i=0; i<nOld; i++){
     releasePage(apOld[i]);
   }
@@ -5429,7 +5438,7 @@ static int balance_shallower(MemPage *pPage){
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   pBt = pPage->pBt;
   mxCellPerPage = MX_CELL(pBt);
-  apCell = sqlite3_malloc( mxCellPerPage*(sizeof(u8*)+sizeof(u16)) );
+  apCell = sqlite3Malloc( mxCellPerPage*(sizeof(u8*)+sizeof(u16)) );
   if( apCell==0 ) return SQLITE_NOMEM;
   szCell = (u16*)&apCell[mxCellPerPage];
   if( pPage->leaf ){
@@ -5673,7 +5682,7 @@ static int checkReadLocks(
 */
 static void allocateTempSpace(BtShared *pBt){
   if( !pBt->pTmpSpace ){
-    pBt->pTmpSpace = sqlite3_malloc(MX_CELL_SIZE(pBt));
+    pBt->pTmpSpace = sqlite3Malloc(MX_CELL_SIZE(pBt));
   }
 }
 
@@ -6729,7 +6738,7 @@ char *sqlite3BtreeIntegrityCheck(
     sqlite3BtreeLeave(p);
     return 0;
   }
-  sCheck.anRef = sqlite3_malloc( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
+  sCheck.anRef = sqlite3Malloc( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
   if( !sCheck.anRef ){
     unlockBtreeIfUnused(pBt);
     *pnErr = 1;

src/btreeInt.h

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btreeInt.h,v 1.21 2008/04/24 19:15:10 shane Exp $
+** $Id: btreeInt.h,v 1.22 2008/06/15 02:51:47 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -371,9 +371,6 @@ struct BtShared {
   MemPage *pPage1;      /* First page of the database */
   u8 inStmt;            /* True if we are in a statement subtransaction */
   u8 readOnly;          /* True if the underlying file is readonly */
-  u8 maxEmbedFrac;      /* Maximum payload as % of total page size */
-  u8 minEmbedFrac;      /* Minimum payload as % of total page size */
-  u8 minLeafFrac;       /* Minimum leaf payload as % of total page size */
   u8 pageSizeFixed;     /* True if the page size can no longer be changed */
 #ifndef SQLITE_OMIT_AUTOVACUUM
   u8 autoVacuum;        /* True if auto-vacuum is enabled */

src/build.c

@@ -22,7 +22,7 @@
 **     COMMIT
 **     ROLLBACK
 **
-** $Id: build.c,v 1.484 2008/05/01 17:16:53 drh Exp $
+** $Id: build.c,v 1.485 2008/06/15 02:51:47 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1367,7 +1367,7 @@ static char *createTableStmt(sqlite3 *db, Table *p, int isTemp){
     zEnd = "\n)";
   }
   n += 35 + 6*p->nCol;
-  zStmt = sqlite3_malloc( n );
+  zStmt = sqlite3Malloc( n );
   if( zStmt==0 ){
     db->mallocFailed = 1;
     return 0;

src/date.c

@@ -16,7 +16,7 @@
 ** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: date.c,v 1.83 2008/06/12 16:35:38 drh Exp $
+** $Id: date.c,v 1.84 2008/06/15 02:51:47 drh Exp $
 **
 ** SQLite processes all times and dates as Julian Day numbers.  The
 ** dates and times are stored as the number of days since noon
@@ -888,7 +888,7 @@ static void strftimeFunc(
     sqlite3_result_error_toobig(context);
     return;
   }else{
-    z = sqlite3_malloc( n );
+    z = sqlite3Malloc( n );
     if( z==0 ){
       sqlite3_result_error_nomem(context);
       return;

src/func.c

@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.192 2008/04/27 18:40:12 drh Exp $
+** $Id: func.c,v 1.193 2008/06/15 02:51:47 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -249,7 +249,7 @@ static void *contextMalloc(sqlite3_context *context, i64 nByte){
     sqlite3_result_error_toobig(context);
     z = 0;
   }else{
-    z = sqlite3_malloc(nByte);
+    z = sqlite3Malloc(nByte);
     if( !z && nByte>0 ){
       sqlite3_result_error_nomem(context);
     }

src/hash.c

@@ -12,7 +12,7 @@
 ** This is the implementation of generic hash-tables
 ** used in SQLite.
 **
-** $Id: hash.c,v 1.28 2008/05/13 13:27:34 drh Exp $
+** $Id: hash.c,v 1.29 2008/06/15 02:51:47 drh Exp $
 */
 #include "sqliteInt.h"
 #include <assert.h>
@@ -387,10 +387,10 @@ void *sqlite3HashInsert(Hash *pH, const void *pKey, int nKey, void *data){
     }
   }
   if( data==0 ) return 0;
-  new_elem = (HashElem*)sqlite3_malloc( sizeof(HashElem) );
+  new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
   if( new_elem==0 ) return data;
   if( pH->copyKey && pKey!=0 ){
-    new_elem->pKey = sqlite3_malloc( nKey );
+    new_elem->pKey = sqlite3Malloc( nKey );
     if( new_elem->pKey==0 ){
       sqlite3_free(new_elem);
       return data;

src/legacy.c

@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: legacy.c,v 1.26 2008/05/20 15:44:31 drh Exp $
+** $Id: legacy.c,v 1.27 2008/06/15 02:51:47 drh Exp $
 */
 
 #include "sqliteInt.h"
@@ -133,7 +133,7 @@ exec_out:
   rc = sqlite3ApiExit(db, rc);
   if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
     int nErrMsg = 1 + strlen(sqlite3_errmsg(db));
-    *pzErrMsg = sqlite3_malloc(nErrMsg);
+    *pzErrMsg = sqlite3Malloc(nErrMsg);
     if( *pzErrMsg ){
       memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
     }

src/malloc.c

@@ -12,7 +12,7 @@
 **
 ** Memory allocation functions used throughout sqlite.
 **
-** $Id: malloc.c,v 1.16 2008/06/14 16:56:22 drh Exp $
+** $Id: malloc.c,v 1.17 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include <stdarg.h>
@@ -90,7 +90,8 @@ static struct {
   */
   sqlite3_int64 nowUsed;  /* Main memory currently in use */
   sqlite3_int64 mxUsed;   /* Highwater mark for nowUsed */
-  int mxReq;              /* maximum request size for main or page-cache mem */
+  int mxReq;              /* Max request size for ordinary mallocs */
+  int mxTempReq;          /* Max request size for xTemp mallocs */
 } mem0;
 
 /*
@@ -226,6 +227,55 @@ void *sqlite3_malloc(int n){
   return sqlite3Malloc(n);
 }
 
+/*
+** Each thread may only have a single outstanding allocation from
+** xTempMalloc().  We verify this constraint in the single-threaded
+** case by setting tempAllocOut to 1 when an allocation
+** is outstanding clearing it when the allocation is freed.
+*/
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+static int tempAllocOut = 0;
+#endif
+
+
+/*
+** Allocate memory that is to be used and released right away.
+** This routine is similar to alloca() in that it is not intended
+** for situations where the memory might be held long-term.  This
+** routine is intended to get memory to old large transient data
+** structures that would not normally fit on the stack of an
+** embedded processor.
+*/
+void *sqlite3TempMalloc(int n){
+  void *p;
+  assert( n>0 );
+  if( sqlite3FaultStep(SQLITE_FAULTINJECTOR_MALLOC) ){
+    return 0;
+  }
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+  assert( tempAllocOut==0 );
+  tempAllocOut = 1;
+#endif
+  if( sqlite3Config.bMemstat ){
+    sqlite3_mutex_enter(mem0.mutex);
+    if( n>mem0.mxTempReq ) mem0.mxTempReq = n;
+    p = sqlite3Config.m.xTempMalloc(n);
+    sqlite3_mutex_leave(mem0.mutex);
+  }else{
+    p = sqlite3Config.m.xTempMalloc(n);
+  }
+  return p;
+}
+void sqlite3TempFree(void *p){
+  if( p ){
+#if SQLITE_THREADSAFE==0 && !defined(NDEBUG)
+    assert( tempAllocOut==1 );
+    tempAllocOut = 0;
+#endif
+    sqlite3Config.m.xTempFree(p);
+  }
+}
+
 /*
 ** Return the size of a memory allocation previously obtained from
 ** sqlite3Malloc() or sqlite3_malloc().
@@ -386,14 +436,14 @@ char *sqlite3StrDup(const char *z){
   int n;
   if( z==0 ) return 0;
   n = strlen(z)+1;
-  zNew = sqlite3_malloc(n);
+  zNew = sqlite3Malloc(n);
   if( zNew ) memcpy(zNew, z, n);
   return zNew;
 }
 char *sqlite3StrNDup(const char *z, int n){
   char *zNew;
   if( z==0 ) return 0;
-  zNew = sqlite3_malloc(n+1);
+  zNew = sqlite3Malloc(n+1);
   if( zNew ){
     memcpy(zNew, z, n);
     zNew[n] = 0;
@@ -437,7 +487,7 @@ void sqlite3SetString(char **pz, ...){
   }
   va_end(ap);
   sqlite3_free(*pz);
-  *pz = zResult = sqlite3_malloc(nByte);
+  *pz = zResult = sqlite3Malloc(nByte);
   if( zResult==0 ){
     return;
   }

src/mem1.c

@@ -17,7 +17,7 @@
 ** This file contains implementations of the low-level memory allocation
 ** routines specified in the sqlite3_mem_methods object.
 **
-** $Id: mem1.c,v 1.19 2008/06/14 16:56:22 drh Exp $
+** $Id: mem1.c,v 1.20 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -130,6 +130,8 @@ void sqlite3MemSetDefault(void){
      sqlite3MemRealloc,
      sqlite3MemSize,
      sqlite3MemRoundup,
+     sqlite3MemMalloc,
+     sqlite3MemFree,
      sqlite3MemInit,
      sqlite3MemShutdown,
      0

src/mem2.c

@@ -19,7 +19,7 @@
 ** This file contains implementations of the low-level memory allocation
 ** routines specified in the sqlite3_mem_methods object.
 **
-** $Id: mem2.c,v 1.28 2008/06/14 16:56:22 drh Exp $
+** $Id: mem2.c,v 1.29 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -312,6 +312,8 @@ void sqlite3MemSetDefault(void){
      sqlite3MemRealloc,
      sqlite3MemSize,
      sqlite3MemRoundup,
+     sqlite3MemMalloc,
+     sqlite3MemFree,
      sqlite3MemInit,
      sqlite3MemShutdown,
      0

src/mutex.c

@@ -19,7 +19,7 @@
 ** implementation is suitable for testing.
 ** debugging purposes
 **
-** $Id: mutex.c,v 1.19 2008/06/14 16:56:23 drh Exp $
+** $Id: mutex.c,v 1.20 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -55,7 +55,7 @@ sqlite3_mutex *sqlite3_mutex_alloc(int id){
   switch( id ){
     case SQLITE_MUTEX_FAST:
     case SQLITE_MUTEX_RECURSIVE: {
-      pNew = sqlite3_malloc(sizeof(*pNew));
+      pNew = sqlite3Malloc(sizeof(*pNew));
       if( pNew ){
         pNew->id = id;
         pNew->cnt = 0;

src/mutex.h

@@ -19,7 +19,7 @@
 ** Source files should #include the sqliteInt.h file and let that file
 ** include this one indirectly.
 **
-** $Id: mutex.h,v 1.3 2008/06/13 18:24:27 drh Exp $
+** $Id: mutex.h,v 1.4 2008/06/15 02:51:48 drh Exp $
 */
 
 
@@ -77,7 +77,7 @@
 #define sqlite3_mutex_leave(X)
 #define sqlite3_mutex_held(X)     1
 #define sqlite3_mutex_notheld(X)  1
-#define sqlite3_mutex_init()
+#define sqlite3_mutex_init()      SQLITE_OK
 #define sqlite3_mutex_end()
 #endif
 

src/os.c

@@ -13,7 +13,7 @@
 ** This file contains OS interface code that is common to all
 ** architectures.
 **
-** $Id: os.c,v 1.112 2008/06/13 18:24:27 drh Exp $
+** $Id: os.c,v 1.113 2008/06/15 02:51:48 drh Exp $
 */
 #define _SQLITE_OS_C_ 1
 #include "sqliteInt.h"
@@ -38,7 +38,7 @@
 */
 #if defined(SQLITE_TEST) && (OS_WIN==0)
   #define DO_OS_MALLOC_TEST if (1) {            \
-    void *pTstAlloc = sqlite3_malloc(10);       \
+    void *pTstAlloc = sqlite3Malloc(10);       \
     if (!pTstAlloc) return SQLITE_IOERR_NOMEM;  \
     sqlite3_free(pTstAlloc);                    \
   }
@@ -168,7 +168,7 @@ int sqlite3OsOpenMalloc(
 ){
   int rc = SQLITE_NOMEM;
   sqlite3_file *pFile;
-  pFile = (sqlite3_file *)sqlite3_malloc(pVfs->szOsFile);
+  pFile = (sqlite3_file *)sqlite3Malloc(pVfs->szOsFile);
   if( pFile ){
     rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);
     if( rc!=SQLITE_OK ){

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.456 2008/06/07 08:58:22 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.457 2008/06/15 02:51:48 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1650,7 +1650,7 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
   /* Open the master journal file exclusively in case some other process
   ** is running this routine also. Not that it makes too much difference.
   */
-  pMaster = (sqlite3_file *)sqlite3_malloc(pVfs->szOsFile * 2);
+  pMaster = (sqlite3_file *)sqlite3Malloc(pVfs->szOsFile * 2);
   pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);
   if( !pMaster ){
     rc = SQLITE_NOMEM;
@@ -1672,7 +1672,7 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
     /* Load the entire master journal file into space obtained from
     ** sqlite3_malloc() and pointed to by zMasterJournal. 
     */
-    zMasterJournal = (char *)sqlite3_malloc(nMasterJournal + nMasterPtr);
+    zMasterJournal = (char *)sqlite3Malloc(nMasterJournal + nMasterPtr);
     if( !zMasterJournal ){
       rc = SQLITE_NOMEM;
       goto delmaster_out;
@@ -2193,7 +2193,7 @@ int sqlite3PagerOpen(
   */
   if( zFilename && zFilename[0] ){
     nPathname = pVfs->mxPathname+1;
-    zPathname = sqlite3_malloc(nPathname*2);
+    zPathname = sqlite3Malloc(nPathname*2);
     if( zPathname==0 ){
       return SQLITE_NOMEM;
     }
@@ -2421,7 +2421,7 @@ int sqlite3PagerSetPagesize(Pager *pPager, u16 *pPageSize){
   if( pageSize && pageSize!=pPager->pageSize 
    && !pPager->memDb && pPager->nRef==0 
   ){
-    char *pNew = (char *)sqlite3_malloc(pageSize);
+    char *pNew = (char *)sqlite3Malloc(pageSize);
     if( !pNew ){
       rc = SQLITE_NOMEM;
     }else{
@@ -3647,9 +3647,9 @@ static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
     pagerLeave(pPager);
     nByteHdr = sizeof(*pPg) + sizeof(u32) + pPager->nExtra
               + MEMDB*sizeof(PgHistory);
-    pPg = sqlite3_malloc( nByteHdr );
+    pPg = sqlite3Malloc( nByteHdr );
     if( pPg ){
-      pData = sqlite3_malloc( pPager->pageSize );
+      pData = sqlite3Malloc( pPager->pageSize );
       if( pData==0 ){
         sqlite3_free(pPg);
         pPg = 0;
@@ -4223,7 +4223,7 @@ static int pager_write(PgHdr *pPg){
           PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
           PAGERTRACE3("JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno);
           assert( pHist->pOrig==0 );
-          pHist->pOrig = sqlite3_malloc( pPager->pageSize );
+          pHist->pOrig = sqlite3Malloc( pPager->pageSize );
           if( !pHist->pOrig ){
             return SQLITE_NOMEM;
           }
@@ -4293,7 +4293,7 @@ static int pager_write(PgHdr *pPg){
       if( MEMDB ){
         PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
         assert( pHist->pStmt==0 );
-        pHist->pStmt = sqlite3_malloc( pPager->pageSize );
+        pHist->pStmt = sqlite3Malloc( pPager->pageSize );
         if( pHist->pStmt ){
           memcpy(pHist->pStmt, PGHDR_TO_DATA(pPg), pPager->pageSize);
         }

src/prepare.c

@@ -13,7 +13,7 @@
 ** interface, and routines that contribute to loading the database schema
 ** from disk.
 **
-** $Id: prepare.c,v 1.86 2008/05/23 14:49:49 drh Exp $
+** $Id: prepare.c,v 1.87 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -448,7 +448,7 @@ static int schemaIsValid(sqlite3 *db){
   int cookie;
   int allOk = 1;
 
-  curTemp = (BtCursor *)sqlite3_malloc(sqlite3BtreeCursorSize());
+  curTemp = (BtCursor *)sqlite3Malloc(sqlite3BtreeCursorSize());
   if( curTemp ){
     assert( sqlite3_mutex_held(db->mutex) );
     for(iDb=0; allOk && iDb<db->nDb; iDb++){

src/printf.c

@@ -5,7 +5,7 @@
 ** an historical reference.  Most of the "enhancements" have been backed
 ** out so that the functionality is now the same as standard printf().
 **
-** $Id: printf.c,v 1.85 2008/05/16 04:51:55 danielk1977 Exp $
+** $Id: printf.c,v 1.86 2008/06/15 02:51:48 drh Exp $
 **
 **************************************************************************
 **
@@ -650,7 +650,7 @@ static void vxprintf(
         needQuote = !isnull && xtype==etSQLESCAPE2;
         n += i + 1 + needQuote*2;
         if( n>etBUFSIZE ){
-          bufpt = zExtra = sqlite3_malloc( n );
+          bufpt = zExtra = sqlite3Malloc( n );
           if( bufpt==0 ) return;
         }else{
           bufpt = buf;
@@ -752,7 +752,7 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
       }else{
         p->nAlloc = szNew;
       }
-      zNew = sqlite3_malloc( p->nAlloc );
+      zNew = sqlite3Malloc( p->nAlloc );
       if( zNew ){
         memcpy(zNew, p->zText, p->nChar);
         sqlite3StrAccumReset(p);
@@ -777,7 +777,7 @@ char *sqlite3StrAccumFinish(StrAccum *p){
   if( p->zText ){
     p->zText[p->nChar] = 0;
     if( p->useMalloc && p->zText==p->zBase ){
-      p->zText = sqlite3_malloc( p->nChar+1 );
+      p->zText = sqlite3Malloc( p->nChar+1 );
       if( p->zText ){
         memcpy(p->zText, p->zBase, p->nChar+1);
       }else{

src/sqlite.h.in

@@ -30,7 +30,7 @@
 ** the version number) and changes its name to "sqlite3.h" as
 ** part of the build process.
 **
-** @(#) $Id: sqlite.h.in,v 1.327 2008/06/14 16:56:23 drh Exp $
+** @(#) $Id: sqlite.h.in,v 1.328 2008/06/15 02:51:48 drh Exp $
 */
 #ifndef _SQLITE3_H_
 #define _SQLITE3_H_
@@ -977,6 +977,14 @@ int sqlite3_config(int, ...);
 ** allocators round up memory allocations at least to the next multiple
 ** of 8.  Some round up to a larger multiple or to a power of 2. 
 **
+** The xTempMalloc and xTempFree methods are used to allocate a large
+** chunk of temporary-use memory whose lifetime is a single procedure
+** call.  These routines may be the same as xMalloc and xFree, if desired,
+** though some specialized applications may benefit from using a different
+** allocation algorithm in this case. 
+** SQLite will never request more than one outstanding memory allocation
+** per thread using xTempMalloc.
+**
 ** The xInit method initializes the memory allocator.  (For example,
 ** it might allocate any require mutexes or initialize internal data
 ** structures.  The xShutdown method is invoked (indirectly) by
@@ -991,6 +999,8 @@ struct sqlite3_mem_methods {
   void *(*xRealloc)(void*,int);  /* Resize an allocation */
   int (*xSize)(void*);           /* Return the size of an allocation */
   int (*xRoundup)(int);          /* Round up request size to allocation size */
+  void *(*xTempMalloc)(int);     /* Allocate temporary space */
+  void (*xTempFree)(void*);      /* Free space from xTempMalloc */
   int (*xInit)(void*);           /* Initialize the memory allocator */
   void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
   void *pAppData;                /* Argument to xInit() and xShutdown() */

src/sqliteInt.h

@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.709 2008/06/14 16:56:23 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.710 2008/06/15 02:51:48 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -1791,6 +1791,8 @@ void *sqlite3Realloc(void*, int);
 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
 void *sqlite3DbRealloc(sqlite3 *, void *, int);
 int sqlite3MallocSize(void *);
+void *sqlite3TempMalloc(int);
+void sqlite3TempFree(void*);
 void sqlite3MemSetDefault(void);
 
 int sqlite3IsNaN(double);

src/tokenize.c

@@ -15,7 +15,7 @@
 ** individual tokens and sends those tokens one-by-one over to the
 ** parser for analysis.
 **
-** $Id: tokenize.c,v 1.143 2008/06/02 13:00:33 danielk1977 Exp $
+** $Id: tokenize.c,v 1.144 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -393,7 +393,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
   pParse->rc = SQLITE_OK;
   pParse->zTail = pParse->zSql = zSql;
   i = 0;
-  pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3_malloc);
+  pEngine = sqlite3ParserAlloc((void*(*)(size_t))sqlite3Malloc);
   if( pEngine==0 ){
     db->mallocFailed = 1;
     return SQLITE_NOMEM;

src/vdbe.c

@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.748 2008/06/07 08:58:22 danielk1977 Exp $
+** $Id: vdbe.c,v 1.749 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -3380,7 +3380,7 @@ case OP_Insert: {
         pData->zMalloc = 0;
       }
     }else{
-      pC->pData = sqlite3_malloc( pC->nData+2 );
+      pC->pData = sqlite3Malloc( pC->nData+2 );
       if( !pC->pData ) goto no_mem;
       memcpy(pC->pData, pData->z, pC->nData);
       pC->pData[pC->nData] = 0;
@@ -4140,7 +4140,7 @@ case OP_IntegrityCk: {
   
   nRoot = pOp->p2;
   assert( nRoot>0 );
-  aRoot = sqlite3_malloc( sizeof(int)*(nRoot+1) );
+  aRoot = sqlite3Malloc( sizeof(int)*(nRoot+1) );
   if( aRoot==0 ) goto no_mem;
   assert( pOp->p3>0 && pOp->p3<=p->nMem );
   pnErr = &p->aMem[pOp->p3];

src/vdbeaux.c

@@ -14,7 +14,7 @@
 ** to version 2.8.7, all this code was combined into the vdbe.c source file.
 ** But that file was getting too big so this subroutines were split out.
 **
-** $Id: vdbeaux.c,v 1.386 2008/06/06 15:04:37 drh Exp $
+** $Id: vdbeaux.c,v 1.387 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -547,7 +547,7 @@ void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
 
     nField = ((KeyInfo*)zP4)->nField;
     nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
-    pKeyInfo = sqlite3_malloc( nByte );
+    pKeyInfo = sqlite3Malloc( nByte );
     pOp->p4.pKeyInfo = pKeyInfo;
     if( pKeyInfo ){
       memcpy(pKeyInfo, zP4, nByte);

src/vdbefifo.c

@@ -12,7 +12,7 @@
 ** This file implements a FIFO queue of rowids used for processing
 ** UPDATE and DELETE statements.
 **
-** $Id: vdbefifo.c,v 1.6 2008/05/16 04:51:55 danielk1977 Exp $
+** $Id: vdbefifo.c,v 1.7 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
@@ -38,7 +38,7 @@ static FifoPage *allocateFifoPage(int nEntry){
   if( nEntry>FIFOSIZE_MAX ){
     nEntry = FIFOSIZE_MAX;
   }
-  pPage = sqlite3_malloc( sizeof(FifoPage) + sizeof(i64)*(nEntry-1) );
+  pPage = sqlite3Malloc( sizeof(FifoPage) + sizeof(i64)*(nEntry-1) );
   if( pPage ){
     pPage->nSlot = nEntry;
     pPage->iWrite = 0;

src/where.c

@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.308 2008/06/12 00:07:29 drh Exp $
+** $Id: where.c,v 1.309 2008/06/15 02:51:48 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -228,7 +228,7 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, int flags){
   int idx;
   if( pWC->nTerm>=pWC->nSlot ){
     WhereTerm *pOld = pWC->a;
-    pWC->a = sqlite3_malloc( sizeof(pWC->a[0])*pWC->nSlot*2 );
+    pWC->a = sqlite3Malloc( sizeof(pWC->a[0])*pWC->nSlot*2 );
     if( pWC->a==0 ){
       pWC->pParse->db->mallocFailed = 1;
       if( flags & TERM_DYNAMIC ){