SQLite

  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \
  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/lookaside.c \
  $(TOP)/src/lookaside.h \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \
  $(TOP)/src/mem3.c \
  $(TOP)/src/mem5.c \

#
HDR = \
   $(TOP)/src/btree.h \
   $(TOP)/src/btreeInt.h \
   $(TOP)/src/hash.h \
   $(TOP)/src/hwtime.h \
   keywordhash.h \
   $(TOP)/src/lookaside.h \
   $(TOP)/src/msvc.h \
   $(TOP)/src/mutex.h \
   opcodes.h \
   $(TOP)/src/os.h \
   $(TOP)/src/os_common.h \
   $(TOP)/src/os_setup.h \
   $(TOP)/src/os_win.h \

legacy.lo:	$(TOP)/src/legacy.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/legacy.c

loadext.lo:	$(TOP)/src/loadext.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/loadext.c

lookaside.lo:  $(TOP)/src/lookaside.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/lookaside.c

main.lo:	$(TOP)/src/main.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/main.c

malloc.lo:	$(TOP)/src/malloc.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/malloc.c

mem0.lo:	$(TOP)/src/mem0.c $(HDR)

  $(TOP)\src\fkey.c \
  $(TOP)\src\func.c \
  $(TOP)\src\global.c \
  $(TOP)\src\hash.c \
  $(TOP)\src\insert.c \
  $(TOP)\src\legacy.c \
  $(TOP)\src\loadext.c \
  $(TOP)\src\lookaside.c \
  $(TOP)\src\main.c \
  $(TOP)\src\malloc.c \
  $(TOP)\src\mem0.c \
  $(TOP)\src\mem1.c \
  $(TOP)\src\mem2.c \
  $(TOP)\src\mem3.c \
  $(TOP)\src\mem5.c \

# Core header files, part 1.
#
SRC04 = \
  $(TOP)\src\btree.h \
  $(TOP)\src\btreeInt.h \
  $(TOP)\src\hash.h \
  $(TOP)\src\hwtime.h \
  $(TOP)\src\lookaside.h \
  $(TOP)\src\msvc.h \
  $(TOP)\src\mutex.h \
  $(TOP)\src\os.h \
  $(TOP)\src\os_common.h \
  $(TOP)\src\os_setup.h \
  $(TOP)\src\os_win.h

# Header files used by all library source files.
#
HDR = \
   $(TOP)\src\btree.h \
   $(TOP)\src\btreeInt.h \
   $(TOP)\src\hash.h \
   $(TOP)\src\hwtime.h \
   $(TOP)\src\lookaside.h \
   keywordhash.h \
   $(TOP)\src\msvc.h \
   $(TOP)\src\mutex.h \
   opcodes.h \
   $(TOP)\src\os.h \
   $(TOP)\src\os_common.h \
   $(TOP)\src\os_setup.h \

legacy.lo:	$(TOP)\src\legacy.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\legacy.c

loadext.lo:	$(TOP)\src\loadext.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\loadext.c

lookaside.lo:	$(TOP)\src\lookaside.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\lookaside.c

main.lo:	$(TOP)\src\main.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\main.c

malloc.lo:	$(TOP)\src\malloc.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\malloc.c

mem0.lo:	$(TOP)\src\mem0.c $(HDR)

  $(TOP)/src/global.c \
  $(TOP)/src/hash.c \
  $(TOP)/src/hash.h \
  $(TOP)/src/hwtime.h \
  $(TOP)/src/insert.c \
  $(TOP)/src/legacy.c \
  $(TOP)/src/loadext.c \
  $(TOP)/src/lookaside.c \
  $(TOP)/src/lookaside.h \
  $(TOP)/src/main.c \
  $(TOP)/src/malloc.c \
  $(TOP)/src/mem0.c \
  $(TOP)/src/mem1.c \
  $(TOP)/src/mem2.c \
  $(TOP)/src/mem3.c \
  $(TOP)/src/mem5.c \

#
HDR = \
   $(TOP)/src/btree.h \
   $(TOP)/src/btreeInt.h \
   $(TOP)/src/hash.h \
   $(TOP)/src/hwtime.h \
   keywordhash.h \
   $(TOP)/src/lookaside.h \
   $(TOP)/src/msvc.h \
   $(TOP)/src/mutex.h \
   opcodes.h \
   $(TOP)/src/os.h \
   $(TOP)/src/os_common.h \
   $(TOP)/src/os_setup.h \
   $(TOP)/src/os_win.h \

** of a blob encoding of the complete index key as is found in
** sqlite_stat4.sample.  The nEq, nLt, and nDLt entries of sqlite_stat3
** all contain just a single integer which is the same as the first
** integer in the equivalent columns in sqlite_stat4.
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"
#include "lookaside.h"

#if defined(SQLITE_ENABLE_STAT4)
# define IsStat4     1
#else
# define IsStat4     0
# undef SQLITE_STAT4_SAMPLES
# define SQLITE_STAT4_SAMPLES 1

){
  int rc;                       /* Result codes from subroutines */
  sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */
  char *zSql;                   /* Text of the SQL statement */
  Index *pPrevIdx = 0;          /* Previous index in the loop */
  IndexSample *pSample;         /* A slot in pIdx->aSample[] */

  assert( db->lookaside.bDisable );
  assert( sqlite3LookasideDisabled(&db->lookaside) );
  zSql = sqlite3MPrintf(db, zSql1, zDb);
  if( !zSql ){
    return SQLITE_NOMEM_BKPT;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

/*
** Load content from the sqlite_stat4 table into 
** the Index.aSample[] arrays of all indices.
*/
static int loadStat4(sqlite3 *db, const char *zDb){
  int rc = SQLITE_OK;             /* Result codes from subroutines */

  assert( db->lookaside.bDisable );
  assert( sqlite3LookasideDisabled(&db->lookaside) );
  if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
    rc = loadStatTbl(db,
      "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
      zDb
    );
  }

    Index *pIdx = sqliteHashData(i);
    if( !pIdx->hasStat1 ) sqlite3DefaultRowEst(pIdx);
  }

  /* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT4
  if( rc==SQLITE_OK ){
    DisableLookaside;
    sqlite3LookasideDisable(&db->lookaside);
    rc = loadStat4(db, sInfo.zDatabase);
    EnableLookaside;
    sqlite3LookasideEnable(&db->lookaside);
  }
  for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    sqlite3_free(pIdx->aiRowEst);
    pIdx->aiRowEst = 0;
  }
#endif

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
*/
#include "sqliteInt.h"
#include "lookaside.h"

#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** The TableLock structure is only used by the sqlite3TableLock() and
** codeTableLocks() functions.
*/
struct TableLock {

  ** lookaside, this number should not change. 
  **
  ** If malloc has already failed, it may be that it failed while allocating
  ** a Table object that was going to be marked ephemeral. So do not check
  ** that no lookaside memory is used in this case either. */
  int nLookaside = 0;
  if( db && !db->mallocFailed && (pTable->tabFlags & TF_Ephemeral)==0 ){
    nLookaside = sqlite3LookasideUsed(db, 0);
    nLookaside = sqlite3LookasideUsed(&db->lookaside, 0);
  }
#endif

  /* Delete all indices associated with this table. */
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    assert( pIndex->pSchema==pTable->pSchema

  sqlite3ExprListDelete(db, pTable->pCheck);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3VtabClear(db, pTable);
#endif
  sqlite3DbFree(db, pTable);

  /* Verify that no lookaside memory was used by schema tables */
  assert( nLookaside==0 || nLookaside==sqlite3LookasideUsed(db,0) );
  assert( nLookaside==0 || nLookaside==sqlite3LookasideUsed(&db->lookaside,0) );
}
void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
  /* Do not delete the table until the reference count reaches zero. */
  if( !pTable ) return;
  if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return;
  deleteTable(db, pTable);
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used by the compiler to add foreign key
** support to compiled SQL statements.
*/
#include "sqliteInt.h"
#include "lookaside.h"

#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER

/*
** Deferred and Immediate FKs
** --------------------------

          pWhere,
          0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */
    DisableLookaside;
    sqlite3LookasideDisable(&db->lookaside);

    pTrigger = (Trigger *)sqlite3DbMallocZero(db, 
        sizeof(Trigger) +         /* struct Trigger */
        sizeof(TriggerStep) +     /* Single step in trigger program */
        nFrom + 1                 /* Space for pStep->zTarget */
    );
    if( pTrigger ){

      if( pWhen ){
        pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0);
        pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
      }
    }

    /* Re-enable the lookaside buffer, if it was disabled earlier. */
    EnableLookaside;
    sqlite3LookasideEnable(&db->lookaside);

    sqlite3ExprDelete(db, pWhere);
    sqlite3ExprDelete(db, pWhen);
    sqlite3ExprListDelete(db, pList);
    sqlite3SelectDelete(db, pSelect);
    if( db->mallocFailed==1 ){
      fkTriggerDelete(db, pTrigger);

/*
** 2019-10-02
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Lookaside memory allocation functions used throughout sqlite.
*/

#include "sqliteInt.h"
#include "lookaside.h"

/*
** Return the number of LookasideSlot elements on the linked list
*/
static u32 countLookasideSlots(LookasideSlot *p){
  u32 cnt = 0;
  while( p ){
    p = p->pNext;
    cnt++;
  }
  return cnt;
}

/*
** Count the number of slots of lookaside memory that are outstanding
*/
int sqlite3LookasideUsed(Lookaside *pLookaside, int *pHighwater){
  u32 nInit = countLookasideSlots(pLookaside->pInit);
  u32 nFree = countLookasideSlots(pLookaside->pFree);
  if( pHighwater ) *pHighwater = pLookaside->nSlot - nInit;
  return pLookaside->nSlot - (nInit+nFree);
}

void sqlite3LookasideResetUsed(Lookaside *pLookaside){
  LookasideSlot *p = pLookaside->pFree;
  if( p ){
    while( p->pNext ) p = p->pNext;
    p->pNext = pLookaside->pInit;
    pLookaside->pInit = pLookaside->pFree;
    pLookaside->pFree = 0;
  }
}

#ifndef SQLITE_OMIT_LOOKASIDE

static void *lookasideSlotAlloc(Lookaside *pLookaside){
  LookasideSlot *pBuf;
  if( (pBuf = pLookaside->pFree)!=0 ){
    pLookaside->pFree = pBuf->pNext;
    pLookaside->anStat[0]++;
    return (void*)pBuf;
  }else if( (pBuf = pLookaside->pInit)!=0 ){
    pLookaside->pInit = pBuf->pNext;
    pLookaside->anStat[0]++;
    return (void*)pBuf;
  }else{
    pLookaside->anStat[2]++;
    return 0;
  }
}

static void lookasideSlotFree(Lookaside *pLookaside, void *p){
  LookasideSlot *pBuf = (LookasideSlot*)p;
# ifdef SQLITE_DEBUG
  /* Scribble over the content in the buffer being freed */
  memset(p, 0xaa, pLookaside->szTrue);
# endif
  pBuf->pNext = pLookaside->pFree;
  pLookaside->pFree = pBuf;
}

# ifndef SQLITE_OMIT_MINI_LOOKASIDE
#  ifndef SQLITE_MINI_LOOKASIDE_MIN_SLOT_SIZE
#   define SQLITE_MINI_LOOKASIDE_MIN_SLOT_SIZE 128
#  endif

static void *miniLookasideAlloc(Lookaside *pLookaside){
  LookasideSlot *pMiniSlot;
  LookasideSlot *pSlot;
  int iMiniSlot;
  
  if( !pLookaside->pMini ){
    pSlot = lookasideSlotAlloc(pLookaside);
    if( !pSlot ){
      return 0;
    }
    bzero(pSlot, sizeof(LookasideSlot));
    pLookaside->pMini = pSlot;
  }else{
    pSlot = pLookaside->pMini;
    assert( pSlot->nAlloc );
  }
  
  assert( pSlot->nAlloc < pLookaside->nMini );

  if( (pMiniSlot = pSlot->pFree) ){
    pSlot->pFree = pMiniSlot->pNext;
  }else{
    iMiniSlot = pSlot->nAlloc;
    assert(iMiniSlot < pLookaside->nMini);
    pMiniSlot = (LookasideSlot *)((char *)pSlot + sizeof(LookasideSlot) + (pLookaside->szMini * iMiniSlot));
  }

  /* Remove slot from pMini if it is full of sub-allocations */
  if( ++(pSlot->nAlloc) == pLookaside->nMini ){
    /* Slot is full, dequeue from list */
    if( pSlot->pNext ){
      assert( pSlot->pNext->pPrev == pSlot );
      pSlot->pNext->pPrev = pSlot->pPrev;
    }
    if( pSlot->pPrev ){
      assert( pSlot->pPrev->pNext == pSlot );
      pSlot->pPrev->pNext = pSlot->pNext;
    }else{
      assert( pLookaside->pMini == pSlot );
      pLookaside->pMini = pSlot->pNext;
    }
    pSlot->pNext = pSlot->pPrev = 0;
  }
  return pMiniSlot;
}

static void miniLookasideFree(Lookaside *pLookaside, void *p){
  int iSlotNum = ((u8*)p - (u8*)pLookaside->pStart) / pLookaside->szTrue;
  LookasideSlot *pSlot = (LookasideSlot *)(iSlotNum * pLookaside->szTrue + (u8*)pLookaside->pStart);
  LookasideSlot *pMiniSlot = (LookasideSlot *)p;
  
  assert( pSlot->nAlloc );
  assert( pSlot->nAlloc <= pLookaside->nMini );
  assert( iMiniSlot<pLookaside->nMini );
  
  /* Return slot to pMini list if it was full */
  if( pSlot->nAlloc==pLookaside->nMini ){
    assert( pSlot->pNext == pSlot->pPrev && pSlot->pPrev == 0 );
    if( pLookaside->pMini ){
      assert( !pLookaside->pMini->pPrev );
      pSlot->pNext = pLookaside->pMini;
      pSlot->pNext->pPrev = pSlot;
    }
    pLookaside->pMini = pSlot;
  }
  

#ifdef SQLITE_DEBUG
  memset(p, 0xaa, pLookaside->szMini);
#endif
  pSlot->nAlloc--;
  pMiniSlot->pNext = pSlot->pFree;
  pSlot->pFree = pMiniSlot;

  /* Return slot to the lookaside pool if it is empty */
  if( pSlot->nAlloc == 0 ){
    if( pSlot->pNext ){
      assert( pSlot->pNext->pPrev == pSlot );
      pSlot->pNext->pPrev = pSlot->pPrev;
    }
    if( pSlot->pPrev ){
      assert( pSlot->pPrev->pNext == pSlot );
      pSlot->pPrev->pNext = pSlot->pNext;
    }else{
      assert( pLookaside->pMini==pSlot );
      pLookaside->pMini = pSlot->pNext;
    }
    lookasideSlotFree(pLookaside, pSlot);
  }
}

# else
#  define miniLookasideAlloc(A) lookasideSlotAlloc(A)
#  define miniLookasideFree(A, B) lookasideSlotFree(A, B)
# endif /* !SQLITE_OMIT_MINI_LOOKASIDE */

int sqlite3LookasideOpen(void *pBuf, int sz, int cnt, Lookaside *pLookaside){
  void *pStart;

  if( sqlite3LookasideUsed(pLookaside,0)>0 ){
    return SQLITE_BUSY;
  }
  /* Free any existing lookaside buffer for this handle before
  ** allocating a new one so we don't have to have space for
  ** both at the same time.
  */
  if( pLookaside->bMalloced ){
    sqlite3_free(pLookaside->pStart);
  }
  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
  ** than sizeof(LookasideSlot) to be useful.
  */
  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
  if( cnt<0 ) cnt = 0;
  if( sz==0 || cnt==0 ){
    sz = 0;
    pStart = 0;
  }else if( pBuf==0 ){
    sqlite3BeginBenignMalloc();
    pStart = sqlite3Malloc( sz*(sqlite3_int64)cnt );  /* IMP: R-61949-35727 */
    sqlite3EndBenignMalloc();
    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
  }else{
    pStart = pBuf;
  }
  pLookaside->pStart = pStart;
  pLookaside->pInit = 0;
  pLookaside->pFree = 0;
  pLookaside->sz = (u16)sz;
  pLookaside->szTrue = (u16)sz;
#ifndef SQLITE_OMIT_MINILOOKASIDE
  pLookaside->pMini = 0;
  pLookaside->nMini = (sz - sizeof(LookasideSlot)) / SQLITE_MINI_LOOKASIDE_MIN_SLOT_SIZE;
  if( pLookaside->nMini ){
    pLookaside->szMini = ((sz - sizeof(LookasideSlot)) / pLookaside->nMini) & ~(sizeof(void *) - 1);
  }else{
    pLookaside->szMini = 0;
  }
#endif /* SQLITE_OMIT_MINILOOKASIDE */
  if( pStart ){
    int i;
    LookasideSlot *p;
    assert( sz > (int)sizeof(LookasideSlot*) );
    pLookaside->nSlot = cnt;
    p = (LookasideSlot*)pStart;
    for(i=cnt-1; i>=0; i--){
      p->pNext = pLookaside->pInit;
      pLookaside->pInit = p;
      p = (LookasideSlot*)&((u8*)p)[sz];
    }
    pLookaside->pEnd = p;
    pLookaside->bDisable = 0;
    pLookaside->bMalloced = pBuf==0 ?1:0;
  }else{
    pLookaside->pStart = 0;
    pLookaside->pEnd = 0;
    pLookaside->bDisable = 1;
    pLookaside->bMalloced = 0;
    pLookaside->nSlot = 0;
  }
  return SQLITE_OK;
}

void sqlite3LookasideClose(Lookaside *pLookaside){
  assert( sqlite3LookasideUsed(pLookaside,0)==0 );
  if( pLookaside->bMalloced ){
    sqlite3_free(pLookaside->pStart);
  }
}

int sqlite3IsLookaside(Lookaside *pLookaside, void *p){
  return SQLITE_WITHIN(p, pLookaside->pStart, pLookaside->pEnd);
}

/*
** Returns a pointer to a region at least n bytes in size, or NULL if the
** lookaside allocator has exhausted its available memory.
*/
void *sqlite3LookasideAlloc(Lookaside *pLookaside, u64 n){
  if( n>pLookaside->sz ){
    if( !pLookaside->bDisable ){
      pLookaside->anStat[1]++;
    }
    return 0;
  }
  if( n<=pLookaside->szMini && pLookaside->nMini > 1 ){
    return miniLookasideAlloc(pLookaside);
  }
  return lookasideSlotAlloc(pLookaside);
}

/*
** Free memory previously obtained from sqlite3LookasideAlloc().
*/
void sqlite3LookasideFree(Lookaside *pLookaside, void *p){
  assert( sqlite3IsLookaside(pLookaside, p) );
  if( ((u8*)p - (u8*)pLookaside->pStart) % pLookaside->szTrue == 0 ){
    lookasideSlotFree(pLookaside, p);
  }else{
    miniLookasideFree(pLookaside, p);
  }
}

/*
** Return the size of a memory allocation previously obtained from
** sqlite3LookasideAlloc().
*/
int sqlite3LookasideSize(Lookaside *pLookaside, void *p){
  assert(sqlite3IsLookaside(pLookaside, p));

# ifndef SQLITE_OMIT_MINI_LOOKASIDE
  if( ((u8*)p - (u8*)pLookaside->pStart) % pLookaside->szTrue != 0 ){
    return pLookaside->szMini;
  }else
#endif /* SQLITE_OMIT_MINI_LOOKASIDE */
  {
    return pLookaside->szTrue;
  }
}

#endif /* !SQLITE_OMIT_LOOKASIDE */

/*
** 2019-10-02
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Header file for the lookaside allocator
**
** This header defines the interface to the lookaside allocator.
** The lookaside allocator implements a two-size memory allocator using a
** buffer provided at initialization-time to exploit the fact that 75% of
** SQLite's allocations are <=128B.
*/
#ifndef SQLITE_LOOKASIDE_H
#define SQLITE_LOOKASIDE_H

/*
** Count the number of slots of lookaside memory that are outstanding
*/
int sqlite3LookasideUsed(Lookaside *pLookaside, int *pHighwater);

void sqlite3LookasideResetUsed(Lookaside *pLookaside);

#define sqlite3LookasideDisable(pLookaside) do{(pLookaside)->bDisable++;\
  (pLookaside)->sz=0;}while(0)
#define sqlite3LookasideEnable(pLookaside) do{(pLookaside)->bDisable--;\
  (pLookaside)->sz=(pLookaside)->bDisable?0:(pLookaside)->szTrue;} while(0)
#define sqlite3LookasideEnableCnt(pLookaside, CNT) do{(pLookaside)->bDisable -= (CNT);\
  (pLookaside)->sz=(pLookaside)->bDisable?0:(pLookaside)->szTrue;} while(0)
#define sqlite3LookasideDisabled(pLookaside) ((pLookaside)->bDisable)

# ifndef SQLITE_OMIT_LOOKASIDE

/*
** Set up a lookaside allocator.
** Returns SQLITE_OK on success.
** If lookaside is already active, return SQLITE_BUSY.
**
** If pStart is NULL the space for the lookaside memory is obtained from
** sqlite3_malloc(). If pStart is not NULL then it is sz*cnt bytes of memory
** to use for the lookaside memory.
*/
int sqlite3LookasideOpen(
  void *pBuf,           /* NULL or sz*cnt bytes of memory */
  int sz,               /* Number of bytes in each lookaside slot */
  int cnt,              /* Number of slots */
  Lookaside *pLookaside /* Preallocated space for the Lookaside */
);

/* Reset and close the lookaside object */
void sqlite3LookasideClose(Lookaside *pLookaside);

/*
** Returns TRUE if p is a lookaside memory allocation from db
*/
int sqlite3IsLookaside(Lookaside *pLookaside, void *p);

/*
** Returns a pointer to a region at least n bytes in size, or NULL if the
** lookaside allocator has exhausted its available memory.
*/
void *sqlite3LookasideAlloc(Lookaside *pLookaside, u64 n);

/*
** Free memory previously obtained from sqlite3LookasideAlloc().
*/
void sqlite3LookasideFree(Lookaside *pLookaside, void *p);

/*
** Return the size of a memory allocation previously obtained from
** sqlite3LookasideAlloc().
*/
int sqlite3LookasideSize(Lookaside *pLookaside, void *p);

# else
#  define sqlite3LookasideOpen(A, B, C, D) SQLITE_OK
#  define sqlite3LookasideClose(A)
#  define sqlite3IsLookaside(A, B) 0
#  define sqlite3LookasideAlloc(A, B) 0
#  define sqlite3LookasideFree(A, B) assert(0);
#  define sqlite3LookasideSize(A, B) -1
# endif

#endif /* SQLITE_LOOKASIDE_H */

*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
*/
#include "sqliteInt.h"
#include "lookaside.h"

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
#ifdef SQLITE_ENABLE_RTREE
# include "rtree.h"
#endif

      break;
    }
  }
  va_end(ap);
  return rc;
}

/*
** Set up the lookaside buffers for a database connection.
** Return SQLITE_OK on success.  
** If lookaside is already active, return SQLITE_BUSY.
**
** The sz parameter is the number of bytes in each lookaside slot.
** The cnt parameter is the number of slots.  If pStart is NULL the
** space for the lookaside memory is obtained from sqlite3_malloc().
** If pStart is not NULL then it is sz*cnt bytes of memory to use for
** the lookaside memory.
*/
static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
#ifndef SQLITE_OMIT_LOOKASIDE
  void *pStart;
  
  if( sqlite3LookasideUsed(db,0)>0 ){
    return SQLITE_BUSY;
  }
  /* Free any existing lookaside buffer for this handle before
  ** allocating a new one so we don't have to have space for 
  ** both at the same time.
  */
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
  ** than a pointer to be useful.
  */
  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
  if( cnt<0 ) cnt = 0;
  if( sz==0 || cnt==0 ){
    sz = 0;
    pStart = 0;
  }else if( pBuf==0 ){
    sqlite3BeginBenignMalloc();
    pStart = sqlite3Malloc( sz*(sqlite3_int64)cnt );  /* IMP: R-61949-35727 */
    sqlite3EndBenignMalloc();
    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
  }else{
    pStart = pBuf;
  }
  db->lookaside.pStart = pStart;
  db->lookaside.pInit = 0;
  db->lookaside.pFree = 0;
  db->lookaside.sz = (u16)sz;
  db->lookaside.szTrue = (u16)sz;
  if( pStart ){
    int i;
    LookasideSlot *p;
    assert( sz > (int)sizeof(LookasideSlot*) );
    db->lookaside.nSlot = cnt;
    p = (LookasideSlot*)pStart;
    for(i=cnt-1; i>=0; i--){
      p->pNext = db->lookaside.pInit;
      db->lookaside.pInit = p;
      p = (LookasideSlot*)&((u8*)p)[sz];
    }
    db->lookaside.pEnd = p;
    db->lookaside.bDisable = 0;
    db->lookaside.bMalloced = pBuf==0 ?1:0;
  }else{
    db->lookaside.pStart = db;
    db->lookaside.pEnd = db;
    db->lookaside.bDisable = 1;
    db->lookaside.sz = 0;
    db->lookaside.bMalloced = 0;
    db->lookaside.nSlot = 0;
  }
#endif /* SQLITE_OMIT_LOOKASIDE */
  return SQLITE_OK;
}

/*
** Return the mutex associated with a database connection.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;

      rc = SQLITE_OK;
      break;
    }
    case SQLITE_DBCONFIG_LOOKASIDE: {
      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
      rc = setupLookaside(db, pBuf, sz, cnt);
      rc = sqlite3LookasideOpen(pBuf, sz, cnt, &db->lookaside);
      break;
    }
    default: {
      static const struct {
        int op;      /* The opcode */
        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
      } aFlagOp[] = {

  ** the same sqliteMalloc() as the one that allocates the database 
  ** structure?
  */
  sqlite3DbFree(db, db->aDb[1].pSchema);
  sqlite3_mutex_leave(db->mutex);
  db->magic = SQLITE_MAGIC_CLOSED;
  sqlite3_mutex_free(db->mutex);
  assert( sqlite3LookasideUsed(db,0)==0 );
  sqlite3LookasideClose(&db->lookaside);
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  sqlite3_free(db);
}

/*
** Rollback all database files.  If tripCode is not SQLITE_OK, then
** any write cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further

    }
  }
  sqlite3_mutex_enter(db->mutex);
  db->errMask = 0xff;
  db->nDb = 2;
  db->magic = SQLITE_MAGIC_BUSY;
  db->aDb = db->aDbStatic;
  db->lookaside.bDisable = 1;
  db->lookaside.sz = 0;
  sqlite3LookasideDisable(&db->lookaside);

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->szMmap = sqlite3GlobalConfig.szMmap;

  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
                          SQLITE_DEFAULT_LOCKING_MODE);
#endif

  if( rc ) sqlite3Error(db, rc);

  /* Enable the lookaside-malloc subsystem */
  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
                        sqlite3GlobalConfig.nLookaside);
  sqlite3LookasideOpen(0, sqlite3GlobalConfig.szLookaside,
                        sqlite3GlobalConfig.nLookaside, &db->lookaside);

  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);

opendb_out:
  if( db ){
    assert( db->mutex!=0 || isThreadsafe==0
           || sqlite3GlobalConfig.bFullMutex==0 );

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Memory allocation functions used throughout sqlite.
*/
#include "sqliteInt.h"
#include "lookaside.h"
#include <stdarg.h>

/*
** Attempt to release up to n bytes of non-essential memory currently
** held by SQLite. An example of non-essential memory is memory used to
** cache database pages that are not currently in use.
*/

void *sqlite3_malloc64(sqlite3_uint64 n){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return sqlite3Malloc(n);
}

/*
** TRUE if p is a lookaside memory allocation from db
*/
#ifndef SQLITE_OMIT_LOOKASIDE
static int isLookaside(sqlite3 *db, void *p){
  return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pEnd);
}
#else
#define isLookaside(A,B) 0
#endif

/*
** Return the size of a memory allocation previously obtained from
** sqlite3Malloc() or sqlite3_malloc().
*/
int sqlite3MallocSize(void *p){
  assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
  return sqlite3GlobalConfig.m.xSize(p);
}
int sqlite3DbMallocSize(sqlite3 *db, void *p){
  assert( p!=0 );
  if( db==0 || !isLookaside(db,p) ){
  if( db==0 || !sqlite3IsLookaside(&db->lookaside,p) ){
#ifdef SQLITE_DEBUG
    if( db==0 ){
      assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
      assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
    }else{
      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
    }
#endif
    return sqlite3GlobalConfig.m.xSize(p);
  }else{
    assert( sqlite3_mutex_held(db->mutex) );
    return db->lookaside.szTrue;
    return sqlite3LookasideSize(&db->lookaside, p);
  }
}
sqlite3_uint64 sqlite3_msize(void *p){
  assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );
  assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );
  return p ? sqlite3GlobalConfig.m.xSize(p) : 0;
}

  assert( db==0 || sqlite3_mutex_held(db->mutex) );
  assert( p!=0 );
  if( db ){
    if( db->pnBytesFreed ){
      measureAllocationSize(db, p);
      return;
    }
    if( isLookaside(db, p) ){
      LookasideSlot *pBuf = (LookasideSlot*)p;
#ifdef SQLITE_DEBUG
      /* Trash all content in the buffer being freed */
      memset(p, 0xaa, db->lookaside.szTrue);
#endif
      pBuf->pNext = db->lookaside.pFree;
      db->lookaside.pFree = pBuf;
    if( sqlite3IsLookaside(&db->lookaside, p) ){
      sqlite3LookasideFree(&db->lookaside, p);
      return;
    }
  }
  assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
  assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
  assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

/* Finish the work of sqlite3DbMallocRawNN for the unusual and
** slower case when the allocation cannot be fulfilled using lookaside.
*/
static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){
  void *p;
  assert( db!=0 );
  if( db->mallocFailed ){ return 0; }
  p = sqlite3Malloc(n);
  if( !p ) sqlite3OomFault(db);
  sqlite3MemdebugSetType(p, 
         (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);
    sqlite3LookasideDisabled(&db->lookaside) ? MEMTYPE_HEAP : MEMTYPE_LOOKASIDE);
  return p;
}

/*
** Allocate memory, either lookaside (if possible) or heap.  
** If the allocation fails, set the mallocFailed flag in
** the connection pointer.

  void *p;
  if( db ) return sqlite3DbMallocRawNN(db, n);
  p = sqlite3Malloc(n);
  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
  return p;
}
void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){
#ifndef SQLITE_OMIT_LOOKASIDE
  LookasideSlot *pBuf;
  assert( db!=0 );
  assert( sqlite3_mutex_held(db->mutex) );
  assert( db->pnBytesFreed==0 );
  if( n>db->lookaside.sz ){
#ifndef SQLITE_OMIT_LOOKASIDE
    if( db->lookaside.bDisable ){
      return db->mallocFailed ? 0 : dbMallocRawFinish(db, n);
  return sqlite3LookasideAlloc(&db->lookaside, n) ?: dbMallocRawFinish(db, n);
    }
    db->lookaside.anStat[1]++;
  }else if( (pBuf = db->lookaside.pFree)!=0 ){
    db->lookaside.pFree = pBuf->pNext;
    db->lookaside.anStat[0]++;
    return (void*)pBuf;
  }else if( (pBuf = db->lookaside.pInit)!=0 ){
    db->lookaside.pInit = pBuf->pNext;
    db->lookaside.anStat[0]++;
    return (void*)pBuf;
  }else{
    db->lookaside.anStat[2]++;
  }
#else
  assert( db!=0 );
  assert( sqlite3_mutex_held(db->mutex) );
  assert( db->pnBytesFreed==0 );
  if( db->mallocFailed ){
    return 0;
  }
#endif
  return dbMallocRawFinish(db, n);
#endif
}

/* Forward declaration */
static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n);

/*
** Resize the block of memory pointed to by p to n bytes. If the
** resize fails, set the mallocFailed flag in the connection object.
*/
void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
  assert( db!=0 );
  if( p==0 ) return sqlite3DbMallocRawNN(db, n);
  assert( sqlite3_mutex_held(db->mutex) );
  if( isLookaside(db,p) && n<=db->lookaside.szTrue ) return p;
  if( sqlite3IsLookaside(&db->lookaside,p) && n<=sqlite3LookasideSize(&db->lookaside, p) ) return p;
  return dbReallocFinish(db, p, n);
}
static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){
  void *pNew = 0;
  assert( db!=0 );
  assert( p!=0 );
  if( db->mallocFailed==0 ){
    if( isLookaside(db, p) ){
    if( sqlite3IsLookaside(&db->lookaside,p) ){
      pNew = sqlite3DbMallocRawNN(db, n);
      if( pNew ){
        memcpy(pNew, p, db->lookaside.szTrue);
        memcpy(pNew, p, sqlite3LookasideSize(&db->lookaside, p));
        sqlite3DbFree(db, p);
      }
    }else{
      assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );
      sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
      pNew = sqlite3_realloc64(p, n);
      if( !pNew ){
        sqlite3OomFault(db);
      }
      sqlite3MemdebugSetType(pNew,
            (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));
      sqlite3MemdebugSetType(p,
        sqlite3LookasideDisabled(&db->lookaside) ? MEMTYPE_HEAP : MEMTYPE_LOOKASIDE);
    }
  }
  return pNew;
}

/*
** Attempt to reallocate p.  If the reallocation fails, then free p

void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){
  sqlite3DbFree(db, *pz);
  *pz = sqlite3DbStrDup(db, zNew);
}

/*
** Call this routine to record the fact that an OOM (out-of-memory) error
** has happened.  This routine will set db->mallocFailed, and also
** has happened.  This routine will set db->mallocFailed and interrupt
** temporarily disable the lookaside memory allocator and interrupt
** any running VDBEs.
*/
void sqlite3OomFault(sqlite3 *db){
  if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
    db->mallocFailed = 1;
    if( db->nVdbeExec>0 ){
      db->u1.isInterrupted = 1;
    }
    DisableLookaside;
    sqlite3LookasideDisable(&db->lookaside);;
    if( db->pParse ){
      db->pParse->rc = SQLITE_NOMEM_BKPT;
    }
  }
}

/*
** This routine reactivates the memory allocator and clears the
** db->mallocFailed flag as necessary.
**
** The memory allocator is not restarted if there are running
** VDBEs.
*/
void sqlite3OomClear(sqlite3 *db){
  if( db->mallocFailed && db->nVdbeExec==0 ){
    db->mallocFailed = 0;
    db->u1.isInterrupted = 0;
    assert( db->lookaside.bDisable>0 );
    assert( sqlite3LookasideDisabled(&db->lookaside) );
    EnableLookaside;
  }
}

/*
** Take actions at the end of an API call to indicate an OOM error
*/

%name sqlite3Parser

// The following text is included near the beginning of the C source
// code file that implements the parser.
//
%include {
#include "sqliteInt.h"
#include "lookaside.h"

/*
** Disable all error recovery processing in the parser push-down
** automaton.
*/
#define YYNOERRORRECOVERY 1

/*
** Disable lookaside memory allocation for objects that might be
** shared across database connections.
*/
static void disableLookaside(Parse *pParse){
  sqlite3 *db = pParse->db;
  pParse->disableLookaside++;
  DisableLookaside;
  sqlite3LookasideDisable(&db->lookaside);
}

} // end %include

// Input is a single SQL command
input ::= cmdlist.
cmdlist ::= cmdlist ecmd.

**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
*/
#include "sqliteInt.h"
#include "lookaside.h"

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(
  InitData *pData,     /* Initialization context */

** Free all memory allocations in the pParse object
*/
void sqlite3ParserReset(Parse *pParse){
  sqlite3 *db = pParse->db;
  sqlite3DbFree(db, pParse->aLabel);
  sqlite3ExprListDelete(db, pParse->pConstExpr);
  if( db ){
    assert( db->lookaside.bDisable >= pParse->disableLookaside );
    db->lookaside.bDisable -= pParse->disableLookaside;
    assert( sqlite3LookasideDisabled(&db->lookaside) >= pParse->disableLookaside );
    sqlite3LookasideEnableCnt(&db->lookaside, pParse->disableLookaside);
    db->lookaside.sz = db->lookaside.bDisable ? 0 : db->lookaside.szTrue;
  }
  pParse->disableLookaside = 0;
}

/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/

  assert( sqlite3_mutex_held(db->mutex) );

  /* For a long-term use prepared statement avoid the use of
  ** lookaside memory.
  */
  if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
    sParse.disableLookaside++;
    DisableLookaside;
    sqlite3LookasideDisable(&db->lookaside);
  }
  sParse.disableVtab = (prepFlags & SQLITE_PREPARE_NO_VTAB)!=0;

  /* Check to verify that it is possible to get a read lock on all
  ** database schemas.  The inability to get a read lock indicates that
  ** some other database connection is holding a write-lock, which in
  ** turn means that the other connection has made uncommitted changes

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
*/
#include "sqliteInt.h"
#include "lookaside.h"

/*
** Trace output macros
*/
#if SELECTTRACE_ENABLED
/***/ int sqlite3SelectTrace = 0;
# define SELECTTRACE(K,P,S,X)  \

  u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
  u32 nSlot;              /* Number of lookaside slots allocated */
  u32 anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
  LookasideSlot *pInit;   /* List of buffers not previously used */
  LookasideSlot *pFree;   /* List of available buffers */
  void *pStart;           /* First byte of available memory space */
  void *pEnd;             /* First byte past end of available space */
#ifndef SQLITE_OMIT_MINILOOKASIDE
  LookasideSlot *pMini;   /* List of buffers used by mini allocator */
  u16 szMini;             /* Size of each mini-allocator buffer in bytes */
  u16 nMini;              /* Number of mini-allocator buffers per slot */
#endif /* SQLITE_OMIT_MINILOOKASIDE */
};
struct LookasideSlot {
  LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
  LookasideSlot *pNext;    /* Next buffer in the list of buffers */
#ifndef SQLITE_OMIT_MINILOOKASIDE
  /* The members below are only valid for slots inside the mini-allocator */
  LookasideSlot *pPrev;    /* Previous partially-used buffer in the list */
  u16 nAlloc;              /* Number of sub-allocations ever returned from this slot */
  LookasideSlot *pFree;    /* List of freed sub-allocations */
#endif /* SQLITE_OMIT_MINILOOKASIDE */
};

#define DisableLookaside  db->lookaside.bDisable++;db->lookaside.sz=0
#define EnableLookaside   db->lookaside.bDisable--;\
   db->lookaside.sz=db->lookaside.bDisable?0:db->lookaside.szTrue

/*

# define sqlite3MemoryBarrier()
#endif

sqlite3_int64 sqlite3StatusValue(int);
void sqlite3StatusUp(int, int);
void sqlite3StatusDown(int, int);
void sqlite3StatusHighwater(int, int);
int sqlite3LookasideUsed(sqlite3*,int*);

/* Access to mutexes used by sqlite3_status() */
sqlite3_mutex *sqlite3Pcache1Mutex(void);
sqlite3_mutex *sqlite3MallocMutex(void);

#if defined(SQLITE_ENABLE_MULTITHREADED_CHECKS) && !defined(SQLITE_MUTEX_OMIT)
void sqlite3MutexWarnOnContention(sqlite3_mutex*);

**
*************************************************************************
**
** This module implements the sqlite3_status() interface and related
** functionality.
*/
#include "sqliteInt.h"
#include "lookaside.h"
#include "vdbeInt.h"

/*
** Variables in which to record status information.
*/
#if SQLITE_PTRSIZE>4
typedef sqlite3_int64 sqlite3StatValueType;

  if( rc==0 ){
    *pCurrent = (int)iCur;
    *pHighwater = (int)iHwtr;
  }
  return rc;
}

/*
** Return the number of LookasideSlot elements on the linked list
*/
static u32 countLookasideSlots(LookasideSlot *p){
  u32 cnt = 0;
  while( p ){
    p = p->pNext;
    cnt++;
  }
  return cnt;
}

/*
** Count the number of slots of lookaside memory that are outstanding
*/
int sqlite3LookasideUsed(sqlite3 *db, int *pHighwater){
  u32 nInit = countLookasideSlots(db->lookaside.pInit);
  u32 nFree = countLookasideSlots(db->lookaside.pFree);
  if( pHighwater ) *pHighwater = db->lookaside.nSlot - nInit;
  return db->lookaside.nSlot - (nInit+nFree);
}

/*
** Query status information for a single database connection
*/
int sqlite3_db_status(
  sqlite3 *db,          /* The database connection whose status is desired */
  int op,               /* Status verb */
  int *pCurrent,        /* Write current value here */
  int *pHighwater,      /* Write high-water mark here */
  int resetFlag         /* Reset high-water mark if true */
){
  int rc = SQLITE_OK;   /* Return code */
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  switch( op ){
    case SQLITE_DBSTATUS_LOOKASIDE_USED: {
      *pCurrent = sqlite3LookasideUsed(db, pHighwater);
      *pCurrent = sqlite3LookasideUsed(&db->lookaside, pHighwater);
      if( resetFlag ){
        LookasideSlot *p = db->lookaside.pFree;
        if( p ){
          while( p->pNext ) p = p->pNext;
          p->pNext = db->lookaside.pInit;
          db->lookaside.pInit = db->lookaside.pFree;
          db->lookaside.pFree = 0;
        sqlite3LookasideResetUsed(&db->lookaside);
        }
      }
      break;
    }

    case SQLITE_DBSTATUS_LOOKASIDE_HIT:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
    case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {

#
foreach hdr {
   btree.h
   btreeInt.h
   hash.h
   hwtime.h
   keywordhash.h
   lookaside.h
   msvc.h
   mutex.h
   opcodes.h
   os_common.h
   os_setup.h
   os_win.h
   os.h

   global.c
   ctime.c
   status.c
   date.c
   os.c

   fault.c
   lookaside.c
   mem0.c
   mem1.c
   mem2.c
   mem3.c
   mem5.c
   mutex.c
   mutex_noop.c

   fts3Int.h
   fts3_hash.h
   fts3_tokenizer.h
   geopoly.c
   hash.h
   hwtime.h
   keywordhash.h
   lookaside.h
   msvc.h
   mutex.h
   opcodes.h
   os_common.h
   os_setup.h
   os_win.h
   os.h

   global.c
   status.c
   date.c
   os.c

   fault.c
   lookaside.c
   mem0.c
   mem1.c
   mem2.c
   mem3.c
   mem5.c
   mutex.c
   mutex_noop.c

#
foreach hdr {
   btree.h
   btreeInt.h
   hash.h
   hwtime.h
   keywordhash.h
   lookaside.h
   msvc.h
   opcodes.h
   os_common.h
   os_setup.h
   os_win.h
   os.h
   pager.h