*/
    i = get2byte(&data[hdr+1]);
    while( i>0 ){
      int size, j;
      assert( (u32)i<=usableSize-4 );     /* Enforced by btreeInitPage() */
      size = get2byte(&data[i+2]);
      assert( (u32)(i+size)<=usableSize );  /* Enforced by btreeInitPage() */
      btreeHeapInsert(heap, (((u32)i)<<16)|(i+size-1));
      /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a
      ** big-endian integer which is the offset in the b-tree page of the next
      ** freeblock in the chain, or zero if the freeblock is the last on the
      ** chain. */
      j = get2byte(&data[i]);
      /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
      ** increasing offset. */

   SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
   SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
   (void*)0,                  /* pScratch */
   0,                         /* szScratch */
   0,                         /* nScratch */
   (void*)0,                  /* pPage */
   0,                         /* szPage */
   SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */
   0,                         /* mxParserStack */
   0,                         /* sharedCacheEnabled */
   SQLITE_SORTER_PMASZ,       /* szPma */
   /* All the rest should always be initialized to zero */
   0,                         /* isInit */
   0,                         /* inProgress */
   0,                         /* isMutexInit */

** runtime using sqlite3_config(SQLITE_CONFIG_PCACHE_HDRSZ, &size).  The
** sizes of the extensions sum to 272 bytes on x64 for 3.8.10, but this
** size can vary according to architecture, compile-time options, and
** SQLite library version number.
**
** If SQLITE_PCACHE_SEPARATE_HEADER is defined, then the extension is obtained
** using a separate memory allocation from the database page content.  This
** seeks to overcome the "clownshoe" problem (also called "internal
** fragmentation" in academic literature) of allocating a few bytes more
** than a power of two with the memory allocator rounding up to the next
** power of two, and leaving the rounded-up space unused.
**
** This module tracks pointers to PgHdr1 objects.  Only pcache.c communicates
** with this module.  Information is passed back and forth as PgHdr1 pointers.
**
** The pcache.c and pager.c modules deal pointers to PgHdr objects.
** The btree.c module deals with pointers to MemPage objects.
**
** SOURCE OF PAGE CACHE MEMORY:
**
** Memory for a page might come from any of three sources:
**
**    (1)  The general-purpose memory allocator - sqlite3Malloc()
**    (2)  Global page-cache memory provided using sqlite3_config() with
**         SQLITE_CONFIG_PAGECACHE.
**    (3)  PCache-local bulk allocation.
**
** The third case is a chunk of heap memory (defaulting to 100 pages worth)
** that is allocated when the page cache is created.  The size of the local
** bulk allocation can be adjusted using 
**
**     sqlite3_config(SQLITE_CONFIG_PCACHE, 0, 0, N).
**
** If N is positive, then N pages worth of memory are allocated using a single
** sqlite3Malloc() call and that memory is used for the first N pages allocated.
** Or if N is negative, then -1024*N bytes of memory are allocated and used
** for as many pages as can be accomodated.
**
** Only one of (2) or (3) can be used.  Once the memory available to (2) or
** (3) is exhausted, subsequent allocations fail over to the general-purpose
** memory allocator (1).
**
** Earlier versions of SQLite used only methods (1) and (2).  But experiments
** show that method (3) with N==100 provides about a 5% performance boost for
** common workloads.
*/

#include "sqliteInt.h"

typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
typedef struct PGroup PGroup;

struct PCache1 {
  /* Cache configuration parameters. Page size (szPage) and the purgeable
  ** flag (bPurgeable) are set when the cache is created. nMax may be 
  ** modified at any time by a call to the pcache1Cachesize() method.
  ** The PGroup mutex must be held when accessing nMax.
  */
  PGroup *pGroup;                     /* PGroup this cache belongs to */
  int szPage;                         /* Size of database content section */
  int szExtra;                        /* sizeof(MemPage)+sizeof(PgHdr) */
  int szAlloc;                        /* Total size of one pcache line */
  int bPurgeable;                     /* True if cache is purgeable */
  unsigned int nMin;                  /* Minimum number of pages reserved */
  unsigned int nMax;                  /* Configured "cache_size" value */
  unsigned int n90pct;                /* nMax*9/10 */
  unsigned int iMaxKey;               /* Largest key seen since xTruncate() */

  /* Hash table of all pages. The following variables may only be accessed
  ** when the accessor is holding the PGroup mutex.
  */
  unsigned int nRecyclable;           /* Number of pages in the LRU list */
  unsigned int nPage;                 /* Total number of pages in apHash */
  unsigned int nHash;                 /* Number of slots in apHash[] */
  PgHdr1 **apHash;                    /* Hash table for fast lookup by key */
  PgHdr1 *pFree;                      /* List of unused pcache-local pages */
  void *pBulk;                        /* Bulk memory used by pcache-local */
};

/*
** Each cache entry is represented by an instance of the following 
** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
** in memory.
*/
struct PgHdr1 {
  sqlite3_pcache_page page;
  unsigned int iKey;             /* Key value (page number) */
  u8 isPinned;                   /* Page in use, not on the LRU list */
  u8 isBulkLocal;                /* This page from bulk local storage */
  PgHdr1 *pNext;                 /* Next in hash table chain */
  PCache1 *pCache;               /* Cache that currently owns this page */
  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
};

/*
** Free slots in the allocator used to divide up the global page cache
** buffer provided using the SQLITE_CONFIG_PAGECACHE mechanism.
*/
struct PgFreeslot {
  PgFreeslot *pNext;  /* Next free slot */
};

/*
** Global data used by this cache.
*/
static SQLITE_WSD struct PCacheGlobal {
  PGroup grp;                    /* The global PGroup for mode (2) */

  /* Variables related to SQLITE_CONFIG_PAGECACHE settings.  The
  ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all
  ** fixed at sqlite3_initialize() time and do not require mutex protection.
  ** The nFreeSlot and pFree values do require mutex protection.
  */
  int isInit;                    /* True if initialized */
  int separateCache;             /* Use a new PGroup for each PCache */
  int szSlot;                    /* Size of each free slot */
  int nSlot;                     /* The number of pcache slots */
  int nReserve;                  /* Try to keep nFreeSlot above this */
  void *pStart, *pEnd;           /* Bounds of global page cache memory */
  /* Above requires no mutex.  Use mutex below for variable that follow. */
  sqlite3_mutex *mutex;          /* Mutex for accessing the following: */
  PgFreeslot *pFree;             /* Free page blocks */
  int nFreeSlot;                 /* Number of unused pcache slots */
  /* The following value requires a mutex to change.  We skip the mutex on
  ** reading because (1) most platforms read a 32-bit integer atomically and
  ** (2) even if an incorrect value is read, no great harm is done since this

**
** This routine is called from sqlite3_initialize() and so it is guaranteed
** to be serialized already.  There is no need for further mutexing.
*/
void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){
  if( pcache1.isInit ){
    PgFreeslot *p;
    if( pBuf==0 ) sz = n = 0;
    sz = ROUNDDOWN8(sz);
    pcache1.szSlot = sz;
    pcache1.nSlot = pcache1.nFreeSlot = n;
    pcache1.nReserve = n>90 ? 10 : (n/10 + 1);
    pcache1.pStart = pBuf;
    pcache1.pFree = 0;
    pcache1.bUnderPressure = 0;

  }
  return p;
}

/*
** Free an allocated buffer obtained from pcache1Alloc().
*/
static void pcache1Free(void *p){
  int nFreed = 0;
  if( p==0 ) return;
  if( p>=pcache1.pStart && p<pcache1.pEnd ){
    PgFreeslot *pSlot;
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_USED, 1);
    pSlot = (PgFreeslot*)p;
    pSlot->pNext = pcache1.pFree;
    pcache1.pFree = pSlot;
    pcache1.nFreeSlot++;
    pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
    assert( pcache1.nFreeSlot<=pcache1.nSlot );
    sqlite3_mutex_leave(pcache1.mutex);
  }else{
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

#ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS
    nFreed = sqlite3MallocSize(p);
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);
    sqlite3_mutex_leave(pcache1.mutex);
#endif
    sqlite3_free(p);
  }

}

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*
** Return the size of a pcache allocation
*/
static int pcache1MemSize(void *p){

/*
** Allocate a new page object initially associated with cache pCache.
*/
static PgHdr1 *pcache1AllocPage(PCache1 *pCache){
  PgHdr1 *p = 0;
  void *pPg;

  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
  if( pCache->pFree ){
    p = pCache->pFree;
    pCache->pFree = p->pNext;
    p->pNext = 0;
  }else{
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
    /* The group mutex must be released before pcache1Alloc() is called. This
    ** is because it might call sqlite3_release_memory(), which assumes that 
    ** this mutex is not held. */
    assert( pcache1.separateCache==0 );
    assert( pCache->pGroup==&pcache1.grp );
    pcache1LeaveMutex(pCache->pGroup);
#endif
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
    pPg = pcache1Alloc(pCache->szPage);
    p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);
    if( !pPg || !p ){
      pcache1Free(pPg);
      sqlite3_free(p);
      pPg = 0;
    }
#else
    pPg = pcache1Alloc(pCache->szAlloc);
    p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];
#endif
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
    pcache1EnterMutex(pCache->pGroup);
#endif
    if( pPg==0 ) return 0;
    p->page.pBuf = pPg;
    p->page.pExtra = &p[1];
    p->isBulkLocal = 0;
  }
  if( pCache->bPurgeable ){
    pCache->pGroup->nCurrentPage++;
  }
  return p;


}

/*
** Free a page object allocated by pcache1AllocPage().




*/
static void pcache1FreePage(PgHdr1 *p){
  PCache1 *pCache;
  assert( p!=0 );
  pCache = p->pCache;
  assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );
  if( p->isBulkLocal ){
    p->pNext = pCache->pFree;
    pCache->pFree = p;
  }else{
    pcache1Free(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
    sqlite3_free(p);
#endif
  }
  if( pCache->bPurgeable ){
    pCache->pGroup->nCurrentPage--;

  }
}

/*
** Malloc function used by SQLite to obtain space from the buffer configured
** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer
** exists, this function falls back to sqlite3Malloc().

/*
** Implementation of the sqlite3_pcache.xInit method.
*/
static int pcache1Init(void *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  assert( pcache1.isInit==0 );
  memset(&pcache1, 0, sizeof(pcache1));


  /*
  ** The pcache1.separateCache variable is true if each PCache has its own
  ** private PGroup (mode-1).  pcache1.separateCache is false if the single
  ** PGroup in pcache1.grp is used for all page caches (mode-2).
  **
  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
  **
  **   *  Use a unified cache in single-threaded applications that have
  **      configured a start-time buffer for use as page-cache memory using
  **      sqlite3_config(SQLITE_CONFIG_PAGECACHE, pBuf, sz, N) with non-NULL 
  **      pBuf argument.
  **
  **   *  Otherwise use separate caches (mode-1)
  */
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)
  pcache1.separateCache = 0;
#elif SQLITE_THREADSAFE
  pcache1.separateCache = sqlite3GlobalConfig.pPage==0
                          || sqlite3GlobalConfig.bCoreMutex>0;
#else
  pcache1.separateCache = sqlite3GlobalConfig.pPage==0;
#endif

#if SQLITE_THREADSAFE
  if( sqlite3GlobalConfig.bCoreMutex ){
    pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
    pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM);
  }
#endif
  pcache1.grp.mxPinned = 10;

** Allocate a new cache.
*/
static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
  PCache1 *pCache;      /* The newly created page cache */
  PGroup *pGroup;       /* The group the new page cache will belong to */
  int sz;               /* Bytes of memory required to allocate the new cache */



















  assert( (szPage & (szPage-1))==0 && szPage>=512 && szPage<=65536 );
  assert( szExtra < 300 );

  sz = sizeof(PCache1) + sizeof(PGroup)*pcache1.separateCache;
  pCache = (PCache1 *)sqlite3MallocZero(sz);
  if( pCache ){
    if( pcache1.separateCache ){
      pGroup = (PGroup*)&pCache[1];
      pGroup->mxPinned = 10;
    }else{
      pGroup = &pcache1.grp;
    }
    pCache->pGroup = pGroup;
    pCache->szPage = szPage;
    pCache->szExtra = szExtra;
    pCache->szAlloc = szPage + szExtra + ROUND8(sizeof(PgHdr1));
    pCache->bPurgeable = (bPurgeable ? 1 : 0);
    pcache1EnterMutex(pGroup);
    pcache1ResizeHash(pCache);
    if( bPurgeable ){
      pCache->nMin = 10;
      pGroup->nMinPage += pCache->nMin;
      pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
    }
    pcache1LeaveMutex(pGroup);
    /* Try to initialize the local bulk pagecache line allocation if using
    ** separate caches and if nPage!=0 */
    if( pcache1.separateCache
     && sqlite3GlobalConfig.nPage!=0
     && sqlite3GlobalConfig.pPage==0
    ){
      int szBulk;
      char *zBulk;
      sqlite3BeginBenignMalloc();
      if( sqlite3GlobalConfig.nPage>0 ){
        szBulk = pCache->szAlloc * sqlite3GlobalConfig.nPage;
      }else{
        szBulk = -1024*sqlite3GlobalConfig.nPage;
      }
      zBulk = pCache->pBulk = sqlite3Malloc( szBulk );
      sqlite3EndBenignMalloc();
      if( zBulk ){
        int nBulk = sqlite3MallocSize(zBulk)/pCache->szAlloc;
        int i;
        for(i=0; i<nBulk; i++){
          PgHdr1 *pX = (PgHdr1*)&zBulk[szPage];
          pX->page.pBuf = zBulk;
          pX->page.pExtra = &pX[1];
          pX->isBulkLocal = 1;
          pX->pNext = pCache->pFree;
          pCache->pFree = pX;
          zBulk += pCache->szAlloc;
        }
      }
    }
    if( pCache->nHash==0 ){
      pcache1Destroy((sqlite3_pcache*)pCache);
      pCache = 0;
    }
  }
  return (sqlite3_pcache *)pCache;
}

    return 0;
  }

  if( pCache->nPage>=pCache->nHash ) pcache1ResizeHash(pCache);
  assert( pCache->nHash>0 && pCache->apHash );

  /* Step 4. Try to recycle a page. */
  if( pCache->bPurgeable

   && pGroup->pLruTail
   && ((pCache->nPage+1>=pCache->nMax) || pcache1UnderMemoryPressure(pCache))
  ){
    PCache1 *pOther;
    pPage = pGroup->pLruTail;
    assert( pPage->isPinned==0 );
    pcache1RemoveFromHash(pPage, 0);
    pcache1PinPage(pPage);
    pOther = pPage->pCache;






    if( pOther->szAlloc != pCache->szAlloc ){


      pcache1FreePage(pPage);
      pPage = 0;
    }else{
      pGroup->nCurrentPage -= (pOther->bPurgeable - pCache->bPurgeable);
    }
  }

  assert( pGroup->nMaxPage >= pCache->nMax );
  pGroup->nMaxPage -= pCache->nMax;
  assert( pGroup->nMinPage >= pCache->nMin );
  pGroup->nMinPage -= pCache->nMin;
  pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
  pcache1EnforceMaxPage(pGroup);
  pcache1LeaveMutex(pGroup);
  sqlite3_free(pCache->pBulk);
  sqlite3_free(pCache->apHash);
  sqlite3_free(pCache);
}

/*
** This function is called during initialization (sqlite3_initialize()) to
** install the default pluggable cache module, assuming the user has not

** been released, the function returns. The return value is the total number 
** of bytes of memory released.
*/
int sqlite3PcacheReleaseMemory(int nReq){
  int nFree = 0;
  assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );
  assert( sqlite3_mutex_notheld(pcache1.mutex) );
  if( sqlite3GlobalConfig.nPage==0 ){
    PgHdr1 *p;
    pcache1EnterMutex(&pcache1.grp);
    while( (nReq<0 || nFree<nReq) && ((p=pcache1.grp.pLruTail)!=0) ){
      nFree += pcache1MemSize(p->page.pBuf);
#ifdef SQLITE_PCACHE_SEPARATE_HEADER
      nFree += sqlite3MemSize(p);
#endif

# define SQLITE_DEFAULT_WORKER_THREADS 0
#endif
#if SQLITE_DEFAULT_WORKER_THREADS>SQLITE_MAX_WORKER_THREADS
# undef SQLITE_MAX_WORKER_THREADS
# define SQLITE_MAX_WORKER_THREADS SQLITE_DEFAULT_WORKER_THREADS
#endif

/*
** The default initial allocation for the pagecache when using separate
** pagecaches for each database connection.  A positive number is the
** number of pages.  A negative number N translations means that a buffer
** of -1024*N bytes is allocated and used for as many pages as it will hold.
*/
#ifndef SQLITE_DEFAULT_PCACHE_INITSZ
# define SQLITE_DEFAULT_PCACHE_INITSZ 100
#endif


/*
** GCC does not define the offsetof() macro so we'll have to do it
** ourselves.
*/
#ifndef offsetof
#define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))

    execsql {
      PRAGMA auto_vacuum = full;
      CREATE TABLE t1(a);
      INSERT INTO t1 VALUES(randstr(1000,1000));
      INSERT INTO t1 VALUES(randstr(1000,1000));
      INSERT INTO t1 VALUES(randstr(1000,1000));
    }
    set before [db one {PRAGMA page_count}]

    execsql { DELETE FROM t1 }

    set after [db one {PRAGMA page_count}]
    expr {$before>$after}
  } {1}
}

} ;# ifcapable memorydb

finish_test

set xtra_size 290

# Test 1:  Both PAGECACHE and SCRATCH are shut down.
#
db close
sqlite3_shutdown
sqlite3_config_lookaside 0 0
sqlite3_config_pagecache 0 0
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-1 {PRAGMA page_size=1024}
do_test memsubsys1-1.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 0
do_test memsubsys1-1.4 {

# Test 3:  Activate PAGECACHE with 20 pages but use the wrong page size
# so that PAGECACHE is not used.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache [expr 512+$xtra_size] 20
sqlite3_config singlethread
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-3.1 {PRAGMA page_size=1024}

do_test memsubsys1-3.1.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 0
do_test memsubsys1-3.1.4 {
  set overflow [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]
  # Note:  The measured PAGECACHE_OVERFLOW is amount malloc() returns, not what
  # was requested.  System malloc() implementations might (arbitrarily) return

db close
sqlite3_shutdown
sqlite3_config_memstatus 1
sqlite3_config_pagecache 0 0
sqlite3_config_scratch 0 0
sqlite3_config_lookaside 100 500
sqlite3_config serialized
sqlite3_initialize
autoinstall_test_functions
finish_test

# pages are being used for cache.
#
do_test pcache2-1.1 {
  db close
  sqlite3_reset_auto_extension
  sqlite3_shutdown
  sqlite3_config_pagecache 6000 100
  sqlite3_config singlethread
  sqlite3_initialize
  autoinstall_test_functions
  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0
} {0 0 0}

# Open up two database connections to separate files.

} {0 13 13}

db close
catch {db2 close}
sqlite3_reset_auto_extension
sqlite3_shutdown
sqlite3_config_pagecache 0 0
sqlite3_config serialized
sqlite3_initialize
autoinstall_test_functions

finish_test

  int doIncrvac = 0;            /* True for --incrvacuum */
  const char *zJMode = 0;       /* Journal mode */
  const char *zKey = 0;         /* Encryption key */
  int nLook = 0, szLook = 0;    /* --lookaside configuration */
  int noSync = 0;               /* True for --nosync */
  int pageSize = 0;             /* Desired page size.  0 means default */
  int nPCache = 0, szPCache = 0;/* --pcache configuration */
  int doPCache = 0;             /* True if --pcache is seen */
  int nScratch = 0, szScratch=0;/* --scratch configuration */
  int showStats = 0;            /* True for --stats */
  int nThread = 0;              /* --threads value */
  const char *zTSet = "main";   /* Which --testset torun */
  int doTrace = 0;              /* True for --trace */
  const char *zEncoding = 0;    /* --utf16be or --utf16le */
  const char *zDbName = 0;      /* Name of the test database */

      }else if( strcmp(z,"pagesize")==0 ){
        if( i>=argc-1 ) fatal_error("missing argument on %s\n", argv[i]);
        pageSize = integerValue(argv[++i]);
      }else if( strcmp(z,"pcache")==0 ){
        if( i>=argc-2 ) fatal_error("missing arguments on %s\n", argv[i]);
        nPCache = integerValue(argv[i+1]);
        szPCache = integerValue(argv[i+2]);
        doPCache = 1;
        i += 2;
      }else if( strcmp(z,"primarykey")==0 ){
        g.zPK = "PRIMARY KEY";
      }else if( strcmp(z,"reprepare")==0 ){
        g.bReprepare = 1;
      }else if( strcmp(z,"scratch")==0 ){
        if( i>=argc-2 ) fatal_error("missing arguments on %s\n", argv[i]);

#if SQLITE_VERSION_NUMBER>=3006001
  if( nHeap>0 ){
    pHeap = malloc( nHeap );
    if( pHeap==0 ) fatal_error("cannot allocate %d-byte heap\n", nHeap);
    rc = sqlite3_config(SQLITE_CONFIG_HEAP, pHeap, nHeap, mnHeap);
    if( rc ) fatal_error("heap configuration failed: %d\n", rc);
  }
  if( doPCache ){
    if( nPCache>0 && szPCache>0 ){
      pPCache = malloc( nPCache*(sqlite3_int64)szPCache );
      if( pPCache==0 ) fatal_error("cannot allocate %lld-byte pcache\n",
                                   nPCache*(sqlite3_int64)szPCache);
    }
    rc = sqlite3_config(SQLITE_CONFIG_PAGECACHE, pPCache, szPCache, nPCache);
    if( rc ) fatal_error("pcache configuration failed: %d\n", rc);
  }
  if( nScratch>0 && szScratch>0 ){
    pScratch = malloc( nScratch*(sqlite3_int64)szScratch );
    if( pScratch==0 ) fatal_error("cannot allocate %lld-byte scratch\n",
                                 nScratch*(sqlite3_int64)szScratch);