[sql] Remove SQLite 3.10.2 reference directory.

third_party/sqlite/sqlite-src-3100200/src/vdbeaux.c

-/*
-** 2003 September 6
-**
-** 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.
-**
-*************************************************************************
-** This file contains code used for creating, destroying, and populating
-** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.) 
-*/
-#include "sqliteInt.h"
-#include "vdbeInt.h"
-
-/*
-** Create a new virtual database engine.
-*/
-Vdbe *sqlite3VdbeCreate(Parse *pParse){
-  sqlite3 *db = pParse->db;
-  Vdbe *p;
-  p = sqlite3DbMallocZero(db, sizeof(Vdbe) );
-  if( p==0 ) return 0;
-  p->db = db;
-  if( db->pVdbe ){
-    db->pVdbe->pPrev = p;
-  }
-  p->pNext = db->pVdbe;
-  p->pPrev = 0;
-  db->pVdbe = p;
-  p->magic = VDBE_MAGIC_INIT;
-  p->pParse = pParse;
-  assert( pParse->aLabel==0 );
-  assert( pParse->nLabel==0 );
-  assert( pParse->nOpAlloc==0 );
-  assert( pParse->szOpAlloc==0 );
-  return p;
-}
-
-/*
-** Change the error string stored in Vdbe.zErrMsg
-*/
-void sqlite3VdbeError(Vdbe *p, const char *zFormat, ...){
-  va_list ap;
-  sqlite3DbFree(p->db, p->zErrMsg);
-  va_start(ap, zFormat);
-  p->zErrMsg = sqlite3VMPrintf(p->db, zFormat, ap);
-  va_end(ap);
-}
-
-/*
-** Remember the SQL string for a prepared statement.
-*/
-void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, int isPrepareV2){
-  assert( isPrepareV2==1 || isPrepareV2==0 );
-  if( p==0 ) return;
-#if defined(SQLITE_OMIT_TRACE) && !defined(SQLITE_ENABLE_SQLLOG)
-  if( !isPrepareV2 ) return;
-#endif
-  assert( p->zSql==0 );
-  p->zSql = sqlite3DbStrNDup(p->db, z, n);
-  p->isPrepareV2 = (u8)isPrepareV2;
-}
-
-/*
-** Return the SQL associated with a prepared statement
-*/
-const char *sqlite3_sql(sqlite3_stmt *pStmt){
-  Vdbe *p = (Vdbe *)pStmt;
-  return p ? p->zSql : 0;
-}
-
-/*
-** Swap all content between two VDBE structures.
-*/
-void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
-  Vdbe tmp, *pTmp;
-  char *zTmp;
-  tmp = *pA;
-  *pA = *pB;
-  *pB = tmp;
-  pTmp = pA->pNext;
-  pA->pNext = pB->pNext;
-  pB->pNext = pTmp;
-  pTmp = pA->pPrev;
-  pA->pPrev = pB->pPrev;
-  pB->pPrev = pTmp;
-  zTmp = pA->zSql;
-  pA->zSql = pB->zSql;
-  pB->zSql = zTmp;
-  pB->isPrepareV2 = pA->isPrepareV2;
-}
-
-/*
-** Resize the Vdbe.aOp array so that it is at least nOp elements larger 
-** than its current size. nOp is guaranteed to be less than or equal
-** to 1024/sizeof(Op).
-**
-** If an out-of-memory error occurs while resizing the array, return
-** SQLITE_NOMEM. In this case Vdbe.aOp and Parse.nOpAlloc remain 
-** unchanged (this is so that any opcodes already allocated can be 
-** correctly deallocated along with the rest of the Vdbe).
-*/
-static int growOpArray(Vdbe *v, int nOp){
-  VdbeOp *pNew;
-  Parse *p = v->pParse;
-
-  /* The SQLITE_TEST_REALLOC_STRESS compile-time option is designed to force
-  ** more frequent reallocs and hence provide more opportunities for 
-  ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used
-  ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array
-  ** by the minimum* amount required until the size reaches 512.  Normal
-  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
-  ** size of the op array or add 1KB of space, whichever is smaller. */
-#ifdef SQLITE_TEST_REALLOC_STRESS
-  int nNew = (p->nOpAlloc>=512 ? p->nOpAlloc*2 : p->nOpAlloc+nOp);
-#else
-  int nNew = (p->nOpAlloc ? p->nOpAlloc*2 : (int)(1024/sizeof(Op)));
-  UNUSED_PARAMETER(nOp);
-#endif
-
-  assert( nOp<=(1024/sizeof(Op)) );
-  assert( nNew>=(p->nOpAlloc+nOp) );
-  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
-  if( pNew ){
-    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
-    p->nOpAlloc = p->szOpAlloc/sizeof(Op);
-    v->aOp = pNew;
-  }
-  return (pNew ? SQLITE_OK : SQLITE_NOMEM);
-}
-
-#ifdef SQLITE_DEBUG
-/* This routine is just a convenient place to set a breakpoint that will
-** fire after each opcode is inserted and displayed using
-** "PRAGMA vdbe_addoptrace=on".
-*/
-static void test_addop_breakpoint(void){
-  static int n = 0;
-  n++;
-}
-#endif
-
-/*
-** Add a new instruction to the list of instructions current in the
-** VDBE.  Return the address of the new instruction.
-**
-** Parameters:
-**
-**    p               Pointer to the VDBE
-**
-**    op              The opcode for this instruction
-**
-**    p1, p2, p3      Operands
-**
-** Use the sqlite3VdbeResolveLabel() function to fix an address and
-** the sqlite3VdbeChangeP4() function to change the value of the P4
-** operand.
-*/
-static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
-  assert( p->pParse->nOpAlloc<=p->nOp );
-  if( growOpArray(p, 1) ) return 1;
-  assert( p->pParse->nOpAlloc>p->nOp );
-  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
-}
-int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
-  int i;
-  VdbeOp *pOp;
-
-  i = p->nOp;
-  assert( p->magic==VDBE_MAGIC_INIT );
-  assert( op>0 && op<0xff );
-  if( p->pParse->nOpAlloc<=i ){
-    return growOp3(p, op, p1, p2, p3);
-  }
-  p->nOp++;
-  pOp = &p->aOp[i];
-  pOp->opcode = (u8)op;
-  pOp->p5 = 0;
-  pOp->p1 = p1;
-  pOp->p2 = p2;
-  pOp->p3 = p3;
-  pOp->p4.p = 0;
-  pOp->p4type = P4_NOTUSED;
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-  pOp->zComment = 0;
-#endif
-#ifdef SQLITE_DEBUG
-  if( p->db->flags & SQLITE_VdbeAddopTrace ){
-    int jj, kk;
-    Parse *pParse = p->pParse;
-    for(jj=kk=0; jj<SQLITE_N_COLCACHE; jj++){
-      struct yColCache *x = pParse->aColCache + jj;
-      if( x->iLevel>pParse->iCacheLevel || x->iReg==0 ) continue;
-      printf(" r[%d]={%d:%d}", x->iReg, x->iTable, x->iColumn);
-      kk++;
-    }
-    if( kk ) printf("\n");
-    sqlite3VdbePrintOp(0, i, &p->aOp[i]);
-    test_addop_breakpoint();
-  }
-#endif
-#ifdef VDBE_PROFILE
-  pOp->cycles = 0;
-  pOp->cnt = 0;
-#endif
-#ifdef SQLITE_VDBE_COVERAGE
-  pOp->iSrcLine = 0;
-#endif
-  return i;
-}
-int sqlite3VdbeAddOp0(Vdbe *p, int op){
-  return sqlite3VdbeAddOp3(p, op, 0, 0, 0);
-}
-int sqlite3VdbeAddOp1(Vdbe *p, int op, int p1){
-  return sqlite3VdbeAddOp3(p, op, p1, 0, 0);
-}
-int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
-  return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
-}
-
-/* Generate code for an unconditional jump to instruction iDest
-*/
-int sqlite3VdbeGoto(Vdbe *p, int iDest){
-  return sqlite3VdbeAddOp3(p, OP_Goto, 0, iDest, 0);
-}
-
-/* Generate code to cause the string zStr to be loaded into
-** register iDest
-*/
-int sqlite3VdbeLoadString(Vdbe *p, int iDest, const char *zStr){
-  return sqlite3VdbeAddOp4(p, OP_String8, 0, iDest, 0, zStr, 0);
-}
-
-/*
-** Generate code that initializes multiple registers to string or integer
-** constants.  The registers begin with iDest and increase consecutively.
-** One register is initialized for each characgter in zTypes[].  For each
-** "s" character in zTypes[], the register is a string if the argument is
-** not NULL, or OP_Null if the value is a null pointer.  For each "i" character
-** in zTypes[], the register is initialized to an integer.
-*/
-void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){
-  va_list ap;
-  int i;
-  char c;
-  va_start(ap, zTypes);
-  for(i=0; (c = zTypes[i])!=0; i++){
-    if( c=='s' ){
-      const char *z = va_arg(ap, const char*);
-      int addr = sqlite3VdbeAddOp2(p, z==0 ? OP_Null : OP_String8, 0, iDest++);
-      if( z ) sqlite3VdbeChangeP4(p, addr, z, 0);
-    }else{
-      assert( c=='i' );
-      sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest++);
-    }
-  }
-  va_end(ap);
-}
-
-/*
-** Add an opcode that includes the p4 value as a pointer.
-*/
-int sqlite3VdbeAddOp4(
-  Vdbe *p,            /* Add the opcode to this VM */
-  int op,             /* The new opcode */
-  int p1,             /* The P1 operand */
-  int p2,             /* The P2 operand */
-  int p3,             /* The P3 operand */
-  const char *zP4,    /* The P4 operand */
-  int p4type          /* P4 operand type */
-){
-  int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
-  sqlite3VdbeChangeP4(p, addr, zP4, p4type);
-  return addr;
-}
-
-/*
-** Add an opcode that includes the p4 value with a P4_INT64 or
-** P4_REAL type.
-*/
-int sqlite3VdbeAddOp4Dup8(
-  Vdbe *p,            /* Add the opcode to this VM */
-  int op,             /* The new opcode */
-  int p1,             /* The P1 operand */
-  int p2,             /* The P2 operand */
-  int p3,             /* The P3 operand */
-  const u8 *zP4,      /* The P4 operand */
-  int p4type          /* P4 operand type */
-){
-  char *p4copy = sqlite3DbMallocRaw(sqlite3VdbeDb(p), 8);
-  if( p4copy ) memcpy(p4copy, zP4, 8);
-  return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
-}
-
-/*
-** Add an OP_ParseSchema opcode.  This routine is broken out from
-** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
-** as having been used.
-**
-** The zWhere string must have been obtained from sqlite3_malloc().
-** This routine will take ownership of the allocated memory.
-*/
-void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
-  int j;
-  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
-  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
-  for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
-}
-
-/*
-** Add an opcode that includes the p4 value as an integer.
-*/
-int sqlite3VdbeAddOp4Int(
-  Vdbe *p,            /* Add the opcode to this VM */
-  int op,             /* The new opcode */
-  int p1,             /* The P1 operand */
-  int p2,             /* The P2 operand */
-  int p3,             /* The P3 operand */
-  int p4              /* The P4 operand as an integer */
-){
-  int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
-  sqlite3VdbeChangeP4(p, addr, SQLITE_INT_TO_PTR(p4), P4_INT32);
-  return addr;
-}
-
-/*
-** Create a new symbolic label for an instruction that has yet to be
-** coded.  The symbolic label is really just a negative number.  The
-** label can be used as the P2 value of an operation.  Later, when
-** the label is resolved to a specific address, the VDBE will scan
-** through its operation list and change all values of P2 which match
-** the label into the resolved address.
-**
-** The VDBE knows that a P2 value is a label because labels are
-** always negative and P2 values are suppose to be non-negative.
-** Hence, a negative P2 value is a label that has yet to be resolved.
-**
-** Zero is returned if a malloc() fails.
-*/
-int sqlite3VdbeMakeLabel(Vdbe *v){
-  Parse *p = v->pParse;
-  int i = p->nLabel++;
-  assert( v->magic==VDBE_MAGIC_INIT );
-  if( (i & (i-1))==0 ){
-    p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel, 
-                                       (i*2+1)*sizeof(p->aLabel[0]));
-  }
-  if( p->aLabel ){
-    p->aLabel[i] = -1;
-  }
-  return ADDR(i);
-}
-
-/*
-** Resolve label "x" to be the address of the next instruction to
-** be inserted.  The parameter "x" must have been obtained from
-** a prior call to sqlite3VdbeMakeLabel().
-*/
-void sqlite3VdbeResolveLabel(Vdbe *v, int x){
-  Parse *p = v->pParse;
-  int j = ADDR(x);
-  assert( v->magic==VDBE_MAGIC_INIT );
-  assert( j<p->nLabel );
-  assert( j>=0 );
-  if( p->aLabel ){
-    p->aLabel[j] = v->nOp;
-  }
-  p->iFixedOp = v->nOp - 1;
-}
-
-/*
-** Mark the VDBE as one that can only be run one time.
-*/
-void sqlite3VdbeRunOnlyOnce(Vdbe *p){
-  p->runOnlyOnce = 1;
-}
-
-#ifdef SQLITE_DEBUG /* sqlite3AssertMayAbort() logic */
-
-/*
-** The following type and function are used to iterate through all opcodes
-** in a Vdbe main program and each of the sub-programs (triggers) it may 
-** invoke directly or indirectly. It should be used as follows:
-**
-**   Op *pOp;
-**   VdbeOpIter sIter;
-**
-**   memset(&sIter, 0, sizeof(sIter));
-**   sIter.v = v;                            // v is of type Vdbe* 
-**   while( (pOp = opIterNext(&sIter)) ){
-**     // Do something with pOp
-**   }
-**   sqlite3DbFree(v->db, sIter.apSub);
-** 
-*/
-typedef struct VdbeOpIter VdbeOpIter;
-struct VdbeOpIter {
-  Vdbe *v;                   /* Vdbe to iterate through the opcodes of */
-  SubProgram **apSub;        /* Array of subprograms */
-  int nSub;                  /* Number of entries in apSub */
-  int iAddr;                 /* Address of next instruction to return */
-  int iSub;                  /* 0 = main program, 1 = first sub-program etc. */
-};
-static Op *opIterNext(VdbeOpIter *p){
-  Vdbe *v = p->v;
-  Op *pRet = 0;
-  Op *aOp;
-  int nOp;
-
-  if( p->iSub<=p->nSub ){
-
-    if( p->iSub==0 ){
-      aOp = v->aOp;
-      nOp = v->nOp;
-    }else{
-      aOp = p->apSub[p->iSub-1]->aOp;
-      nOp = p->apSub[p->iSub-1]->nOp;
-    }
-    assert( p->iAddr<nOp );
-
-    pRet = &aOp[p->iAddr];
-    p->iAddr++;
-    if( p->iAddr==nOp ){
-      p->iSub++;
-      p->iAddr = 0;
-    }
-  
-    if( pRet->p4type==P4_SUBPROGRAM ){
-      int nByte = (p->nSub+1)*sizeof(SubProgram*);
-      int j;
-      for(j=0; j<p->nSub; j++){
-        if( p->apSub[j]==pRet->p4.pProgram ) break;
-      }
-      if( j==p->nSub ){
-        p->apSub = sqlite3DbReallocOrFree(v->db, p->apSub, nByte);
-        if( !p->apSub ){
-          pRet = 0;
-        }else{
-          p->apSub[p->nSub++] = pRet->p4.pProgram;
-        }
-      }
-    }
-  }
-
-  return pRet;
-}
-
-/*
-** Check if the program stored in the VM associated with pParse may
-** throw an ABORT exception (causing the statement, but not entire transaction
-** to be rolled back). This condition is true if the main program or any
-** sub-programs contains any of the following:
-**
-**   *  OP_Halt with P1=SQLITE_CONSTRAINT and P2=OE_Abort.
-**   *  OP_HaltIfNull with P1=SQLITE_CONSTRAINT and P2=OE_Abort.
-**   *  OP_Destroy
-**   *  OP_VUpdate
-**   *  OP_VRename
-**   *  OP_FkCounter with P2==0 (immediate foreign key constraint)
-**   *  OP_CreateTable and OP_InitCoroutine (for CREATE TABLE AS SELECT ...)
-**
-** Then check that the value of Parse.mayAbort is true if an
-** ABORT may be thrown, or false otherwise. Return true if it does
-** match, or false otherwise. This function is intended to be used as
-** part of an assert statement in the compiler. Similar to:
-**
-**   assert( sqlite3VdbeAssertMayAbort(pParse->pVdbe, pParse->mayAbort) );
-*/
-int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
-  int hasAbort = 0;
-  int hasFkCounter = 0;
-  int hasCreateTable = 0;
-  int hasInitCoroutine = 0;
-  Op *pOp;
-  VdbeOpIter sIter;
-  memset(&sIter, 0, sizeof(sIter));
-  sIter.v = v;
-
-  while( (pOp = opIterNext(&sIter))!=0 ){
-    int opcode = pOp->opcode;
-    if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 
-     || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
-      && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
-    ){
-      hasAbort = 1;
-      break;
-    }
-    if( opcode==OP_CreateTable ) hasCreateTable = 1;
-    if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
-#ifndef SQLITE_OMIT_FOREIGN_KEY
-    if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
-      hasFkCounter = 1;
-    }
-#endif
-  }
-  sqlite3DbFree(v->db, sIter.apSub);
-
-  /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
-  ** If malloc failed, then the while() loop above may not have iterated
-  ** through all opcodes and hasAbort may be set incorrectly. Return
-  ** true for this case to prevent the assert() in the callers frame
-  ** from failing.  */
-  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter
-              || (hasCreateTable && hasInitCoroutine) );
-}
-#endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */
-
-/*
-** This routine is called after all opcodes have been inserted.  It loops
-** through all the opcodes and fixes up some details.
-**
-** (1) For each jump instruction with a negative P2 value (a label)
-**     resolve the P2 value to an actual address.
-**
-** (2) Compute the maximum number of arguments used by any SQL function
-**     and store that value in *pMaxFuncArgs.
-**
-** (3) Update the Vdbe.readOnly and Vdbe.bIsReader flags to accurately
-**     indicate what the prepared statement actually does.
-**
-** (4) Initialize the p4.xAdvance pointer on opcodes that use it.
-**
-** (5) Reclaim the memory allocated for storing labels.
-*/
-static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
-  int i;
-  int nMaxArgs = *pMaxFuncArgs;
-  Op *pOp;
-  Parse *pParse = p->pParse;
-  int *aLabel = pParse->aLabel;
-  p->readOnly = 1;
-  p->bIsReader = 0;
-  for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
-    u8 opcode = pOp->opcode;
-
-    /* NOTE: Be sure to update mkopcodeh.awk when adding or removing
-    ** cases from this switch! */
-    switch( opcode ){
-      case OP_Transaction: {
-        if( pOp->p2!=0 ) p->readOnly = 0;
-        /* fall thru */
-      }
-      case OP_AutoCommit:
-      case OP_Savepoint: {
-        p->bIsReader = 1;
-        break;
-      }
-#ifndef SQLITE_OMIT_WAL
-      case OP_Checkpoint:
-#endif
-      case OP_Vacuum:
-      case OP_JournalMode: {
-        p->readOnly = 0;
-        p->bIsReader = 1;
-        break;
-      }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-      case OP_VUpdate: {
-        if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
-        break;
-      }
-      case OP_VFilter: {
-        int n;
-        assert( p->nOp - i >= 3 );
-        assert( pOp[-1].opcode==OP_Integer );
-        n = pOp[-1].p1;
-        if( n>nMaxArgs ) nMaxArgs = n;
-        break;
-      }
-#endif
-      case OP_Next:
-      case OP_NextIfOpen:
-      case OP_SorterNext: {
-        pOp->p4.xAdvance = sqlite3BtreeNext;
-        pOp->p4type = P4_ADVANCE;
-        break;
-      }
-      case OP_Prev:
-      case OP_PrevIfOpen: {
-        pOp->p4.xAdvance = sqlite3BtreePrevious;
-        pOp->p4type = P4_ADVANCE;
-        break;
-      }
-    }
-
-    pOp->opflags = sqlite3OpcodeProperty[opcode];
-    if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
-      assert( ADDR(pOp->p2)<pParse->nLabel );
-      pOp->p2 = aLabel[ADDR(pOp->p2)];
-    }
-  }
-  sqlite3DbFree(p->db, pParse->aLabel);
-  pParse->aLabel = 0;
-  pParse->nLabel = 0;
-  *pMaxFuncArgs = nMaxArgs;
-  assert( p->bIsReader!=0 || DbMaskAllZero(p->btreeMask) );
-}
-
-/*
-** Return the address of the next instruction to be inserted.
-*/
-int sqlite3VdbeCurrentAddr(Vdbe *p){
-  assert( p->magic==VDBE_MAGIC_INIT );
-  return p->nOp;
-}
-
-/*
-** This function returns a pointer to the array of opcodes associated with
-** the Vdbe passed as the first argument. It is the callers responsibility
-** to arrange for the returned array to be eventually freed using the 
-** vdbeFreeOpArray() function.
-**
-** Before returning, *pnOp is set to the number of entries in the returned
-** array. Also, *pnMaxArg is set to the larger of its current value and 
-** the number of entries in the Vdbe.apArg[] array required to execute the 
-** returned program.
-*/
-VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg){
-  VdbeOp *aOp = p->aOp;
-  assert( aOp && !p->db->mallocFailed );
-
-  /* Check that sqlite3VdbeUsesBtree() was not called on this VM */
-  assert( DbMaskAllZero(p->btreeMask) );
-
-  resolveP2Values(p, pnMaxArg);
-  *pnOp = p->nOp;
-  p->aOp = 0;
-  return aOp;
-}
-
-/*
-** Add a whole list of operations to the operation stack.  Return the
-** address of the first operation added.
-*/
-int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp, int iLineno){
-  int addr, i;
-  VdbeOp *pOut;
-  assert( nOp>0 );
-  assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
-    return 0;
-  }
-  addr = p->nOp;
-  pOut = &p->aOp[addr];
-  for(i=0; i<nOp; i++, aOp++, pOut++){
-    pOut->opcode = aOp->opcode;
-    pOut->p1 = aOp->p1;
-    pOut->p2 = aOp->p2;
-    assert( aOp->p2>=0 );
-    pOut->p3 = aOp->p3;
-    pOut->p4type = P4_NOTUSED;
-    pOut->p4.p = 0;
-    pOut->p5 = 0;
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-    pOut->zComment = 0;
-#endif
-#ifdef SQLITE_VDBE_COVERAGE
-    pOut->iSrcLine = iLineno+i;
-#else
-    (void)iLineno;
-#endif
-#ifdef SQLITE_DEBUG
-    if( p->db->flags & SQLITE_VdbeAddopTrace ){
-      sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
-    }
-#endif
-  }
-  p->nOp += nOp;
-  return addr;
-}
-
-#if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
-/*
-** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().
-*/
-void sqlite3VdbeScanStatus(
-  Vdbe *p,                        /* VM to add scanstatus() to */
-  int addrExplain,                /* Address of OP_Explain (or 0) */
-  int addrLoop,                   /* Address of loop counter */ 
-  int addrVisit,                  /* Address of rows visited counter */
-  LogEst nEst,                    /* Estimated number of output rows */
-  const char *zName               /* Name of table or index being scanned */
-){
-  int nByte = (p->nScan+1) * sizeof(ScanStatus);
-  ScanStatus *aNew;
-  aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);
-  if( aNew ){
-    ScanStatus *pNew = &aNew[p->nScan++];
-    pNew->addrExplain = addrExplain;
-    pNew->addrLoop = addrLoop;
-    pNew->addrVisit = addrVisit;
-    pNew->nEst = nEst;
-    pNew->zName = sqlite3DbStrDup(p->db, zName);
-    p->aScan = aNew;
-  }
-}
-#endif
-
-
-/*
-** Change the value of the opcode, or P1, P2, P3, or P5 operands
-** for a specific instruction.
-*/
-void sqlite3VdbeChangeOpcode(Vdbe *p, u32 addr, u8 iNewOpcode){
-  sqlite3VdbeGetOp(p,addr)->opcode = iNewOpcode;
-}
-void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
-  sqlite3VdbeGetOp(p,addr)->p1 = val;
-}
-void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
-  sqlite3VdbeGetOp(p,addr)->p2 = val;
-}
-void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
-  sqlite3VdbeGetOp(p,addr)->p3 = val;
-}
-void sqlite3VdbeChangeP5(Vdbe *p, u8 p5){
-  sqlite3VdbeGetOp(p,-1)->p5 = p5;
-}
-
-/*
-** Change the P2 operand of instruction addr so that it points to
-** the address of the next instruction to be coded.
-*/
-void sqlite3VdbeJumpHere(Vdbe *p, int addr){
-  p->pParse->iFixedOp = p->nOp - 1;
-  sqlite3VdbeChangeP2(p, addr, p->nOp);
-}
-
-
-/*
-** If the input FuncDef structure is ephemeral, then free it.  If
-** the FuncDef is not ephermal, then do nothing.
-*/
-static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
-  if( ALWAYS(pDef) && (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
-    sqlite3DbFree(db, pDef);
-  }
-}
-
-static void vdbeFreeOpArray(sqlite3 *, Op *, int);
-
-/*
-** Delete a P4 value if necessary.
-*/
-static void freeP4(sqlite3 *db, int p4type, void *p4){
-  if( p4 ){
-    assert( db );
-    switch( p4type ){
-      case P4_FUNCCTX: {
-        freeEphemeralFunction(db, ((sqlite3_context*)p4)->pFunc);
-        /* Fall through into the next case */
-      }
-      case P4_REAL:
-      case P4_INT64:
-      case P4_DYNAMIC:
-      case P4_INTARRAY: {
-        sqlite3DbFree(db, p4);
-        break;
-      }
-      case P4_KEYINFO: {
-        if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);
-        break;
-      }
-#ifdef SQLITE_ENABLE_CURSOR_HINTS
-      case P4_EXPR: {
-        sqlite3ExprDelete(db, (Expr*)p4);
-        break;
-      }
-#endif
-      case P4_MPRINTF: {
-        if( db->pnBytesFreed==0 ) sqlite3_free(p4);
-        break;
-      }
-      case P4_FUNCDEF: {
-        freeEphemeralFunction(db, (FuncDef*)p4);
-        break;
-      }
-      case P4_MEM: {
-        if( db->pnBytesFreed==0 ){
-          sqlite3ValueFree((sqlite3_value*)p4);
-        }else{
-          Mem *p = (Mem*)p4;
-          if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
-          sqlite3DbFree(db, p);
-        }
-        break;
-      }
-      case P4_VTAB : {
-        if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
-        break;
-      }
-    }
-  }
-}
-
-/*
-** Free the space allocated for aOp and any p4 values allocated for the
-** opcodes contained within. If aOp is not NULL it is assumed to contain 
-** nOp entries. 
-*/
-static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
-  if( aOp ){
-    Op *pOp;
-    for(pOp=aOp; pOp<&aOp[nOp]; pOp++){
-      freeP4(db, pOp->p4type, pOp->p4.p);
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-      sqlite3DbFree(db, pOp->zComment);
-#endif     
-    }
-  }
-  sqlite3DbFree(db, aOp);
-}
-
-/*
-** Link the SubProgram object passed as the second argument into the linked
-** list at Vdbe.pSubProgram. This list is used to delete all sub-program
-** objects when the VM is no longer required.
-*/
-void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){
-  p->pNext = pVdbe->pProgram;
-  pVdbe->pProgram = p;
-}
-
-/*
-** Change the opcode at addr into OP_Noop
-*/
-void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
-  if( addr<p->nOp ){
-    VdbeOp *pOp = &p->aOp[addr];
-    sqlite3 *db = p->db;
-    freeP4(db, pOp->p4type, pOp->p4.p);
-    memset(pOp, 0, sizeof(pOp[0]));
-    pOp->opcode = OP_Noop;
-  }
-}
-
-/*
-** If the last opcode is "op" and it is not a jump destination,
-** then remove it.  Return true if and only if an opcode was removed.
-*/
-int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
-  if( (p->nOp-1)>(p->pParse->iFixedOp) && p->aOp[p->nOp-1].opcode==op ){
-    sqlite3VdbeChangeToNoop(p, p->nOp-1);
-    return 1;
-  }else{
-    return 0;
-  }
-}
-
-/*
-** Change the value of the P4 operand for a specific instruction.
-** This routine is useful when a large program is loaded from a
-** static array using sqlite3VdbeAddOpList but we want to make a
-** few minor changes to the program.
-**
-** If n>=0 then the P4 operand is dynamic, meaning that a copy of
-** the string is made into memory obtained from sqlite3_malloc().
-** A value of n==0 means copy bytes of zP4 up to and including the
-** first null byte.  If n>0 then copy n+1 bytes of zP4.
-** 
-** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
-** to a string or structure that is guaranteed to exist for the lifetime of
-** the Vdbe. In these cases we can just copy the pointer.
-**
-** If addr<0 then change P4 on the most recently inserted instruction.
-*/
-void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
-  Op *pOp;
-  sqlite3 *db;
-  assert( p!=0 );
-  db = p->db;
-  assert( p->magic==VDBE_MAGIC_INIT );
-  if( p->aOp==0 || db->mallocFailed ){
-    if( n!=P4_VTAB ){
-      freeP4(db, n, (void*)*(char**)&zP4);
-    }
-    return;
-  }
-  assert( p->nOp>0 );
-  assert( addr<p->nOp );
-  if( addr<0 ){
-    addr = p->nOp - 1;
-  }
-  pOp = &p->aOp[addr];
-  assert( pOp->p4type==P4_NOTUSED
-       || pOp->p4type==P4_INT32
-       || pOp->p4type==P4_KEYINFO );
-  freeP4(db, pOp->p4type, pOp->p4.p);
-  pOp->p4.p = 0;
-  if( n==P4_INT32 ){
-    /* Note: this cast is safe, because the origin data point was an int
-    ** that was cast to a (const char *). */
-    pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
-    pOp->p4type = P4_INT32;
-  }else if( zP4==0 ){
-    pOp->p4.p = 0;
-    pOp->p4type = P4_NOTUSED;
-  }else if( n==P4_KEYINFO ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_KEYINFO;
-#ifdef SQLITE_ENABLE_CURSOR_HINTS
-  }else if( n==P4_EXPR ){
-    /* Responsibility for deleting the Expr tree is handed over to the
-    ** VDBE by this operation.  The caller should have already invoked
-    ** sqlite3ExprDup() or whatever other routine is needed to make a 
-    ** private copy of the tree. */
-    pOp->p4.pExpr = (Expr*)zP4;
-    pOp->p4type = P4_EXPR;
-#endif
-  }else if( n==P4_VTAB ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = P4_VTAB;
-    sqlite3VtabLock((VTable *)zP4);
-    assert( ((VTable *)zP4)->db==p->db );
-  }else if( n<0 ){
-    pOp->p4.p = (void*)zP4;
-    pOp->p4type = (signed char)n;
-  }else{
-    if( n==0 ) n = sqlite3Strlen30(zP4);
-    pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
-    pOp->p4type = P4_DYNAMIC;
-  }
-}
-
-/*
-** Set the P4 on the most recently added opcode to the KeyInfo for the
-** index given.
-*/
-void sqlite3VdbeSetP4KeyInfo(Parse *pParse, Index *pIdx){
-  Vdbe *v = pParse->pVdbe;
-  assert( v!=0 );
-  assert( pIdx!=0 );
-  sqlite3VdbeChangeP4(v, -1, (char*)sqlite3KeyInfoOfIndex(pParse, pIdx),
-                      P4_KEYINFO);
-}
-
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-/*
-** Change the comment on the most recently coded instruction.  Or
-** insert a No-op and add the comment to that new instruction.  This
-** makes the code easier to read during debugging.  None of this happens
-** in a production build.
-*/
-static void vdbeVComment(Vdbe *p, const char *zFormat, va_list ap){
-  assert( p->nOp>0 || p->aOp==0 );
-  assert( p->aOp==0 || p->aOp[p->nOp-1].zComment==0 || p->db->mallocFailed );
-  if( p->nOp ){
-    assert( p->aOp );
-    sqlite3DbFree(p->db, p->aOp[p->nOp-1].zComment);
-    p->aOp[p->nOp-1].zComment = sqlite3VMPrintf(p->db, zFormat, ap);
-  }
-}
-void sqlite3VdbeComment(Vdbe *p, const char *zFormat, ...){
-  va_list ap;
-  if( p ){
-    va_start(ap, zFormat);
-    vdbeVComment(p, zFormat, ap);
-    va_end(ap);
-  }
-}
-void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){
-  va_list ap;
-  if( p ){
-    sqlite3VdbeAddOp0(p, OP_Noop);
-    va_start(ap, zFormat);
-    vdbeVComment(p, zFormat, ap);
-    va_end(ap);
-  }
-}
-#endif  /* NDEBUG */
-
-#ifdef SQLITE_VDBE_COVERAGE
-/*
-** Set the value if the iSrcLine field for the previously coded instruction.
-*/
-void sqlite3VdbeSetLineNumber(Vdbe *v, int iLine){
-  sqlite3VdbeGetOp(v,-1)->iSrcLine = iLine;
-}
-#endif /* SQLITE_VDBE_COVERAGE */
-
-/*
-** Return the opcode for a given address.  If the address is -1, then
-** return the most recently inserted opcode.
-**
-** If a memory allocation error has occurred prior to the calling of this
-** routine, then a pointer to a dummy VdbeOp will be returned.  That opcode
-** is readable but not writable, though it is cast to a writable value.
-** The return of a dummy opcode allows the call to continue functioning
-** after an OOM fault without having to check to see if the return from 
-** this routine is a valid pointer.  But because the dummy.opcode is 0,
-** dummy will never be written to.  This is verified by code inspection and
-** by running with Valgrind.
-*/
-VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
-  /* C89 specifies that the constant "dummy" will be initialized to all
-  ** zeros, which is correct.  MSVC generates a warning, nevertheless. */
-  static VdbeOp dummy;  /* Ignore the MSVC warning about no initializer */
-  assert( p->magic==VDBE_MAGIC_INIT );
-  if( addr<0 ){
-    addr = p->nOp - 1;
-  }
-  assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
-  if( p->db->mallocFailed ){
-    return (VdbeOp*)&dummy;
-  }else{
-    return &p->aOp[addr];
-  }
-}
-
-#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)
-/*
-** Return an integer value for one of the parameters to the opcode pOp
-** determined by character c.
-*/
-static int translateP(char c, const Op *pOp){
-  if( c=='1' ) return pOp->p1;
-  if( c=='2' ) return pOp->p2;
-  if( c=='3' ) return pOp->p3;
-  if( c=='4' ) return pOp->p4.i;
-  return pOp->p5;
-}
-
-/*
-** Compute a string for the "comment" field of a VDBE opcode listing.
-**
-** The Synopsis: field in comments in the vdbe.c source file gets converted
-** to an extra string that is appended to the sqlite3OpcodeName().  In the
-** absence of other comments, this synopsis becomes the comment on the opcode.
-** Some translation occurs:
-**
-**       "PX"      ->  "r[X]"
-**       "PX@PY"   ->  "r[X..X+Y-1]"  or "r[x]" if y is 0 or 1
-**       "PX@PY+1" ->  "r[X..X+Y]"    or "r[x]" if y is 0
-**       "PY..PY"  ->  "r[X..Y]"      or "r[x]" if y<=x
-*/
-static int displayComment(
-  const Op *pOp,     /* The opcode to be commented */
-  const char *zP4,   /* Previously obtained value for P4 */
-  char *zTemp,       /* Write result here */
-  int nTemp          /* Space available in zTemp[] */
-){
-  const char *zOpName;
-  const char *zSynopsis;
-  int nOpName;
-  int ii, jj;
-  zOpName = sqlite3OpcodeName(pOp->opcode);
-  nOpName = sqlite3Strlen30(zOpName);
-  if( zOpName[nOpName+1] ){
-    int seenCom = 0;
-    char c;
-    zSynopsis = zOpName += nOpName + 1;
-    for(ii=jj=0; jj<nTemp-1 && (c = zSynopsis[ii])!=0; ii++){
-      if( c=='P' ){
-        c = zSynopsis[++ii];
-        if( c=='4' ){
-          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", zP4);
-        }else if( c=='X' ){
-          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", pOp->zComment);
-          seenCom = 1;
-        }else{
-          int v1 = translateP(c, pOp);
-          int v2;
-          sqlite3_snprintf(nTemp-jj, zTemp+jj, "%d", v1);
-          if( strncmp(zSynopsis+ii+1, "@P", 2)==0 ){
-            ii += 3;
-            jj += sqlite3Strlen30(zTemp+jj);
-            v2 = translateP(zSynopsis[ii], pOp);
-            if( strncmp(zSynopsis+ii+1,"+1",2)==0 ){
-              ii += 2;
-              v2++;
-            }
-            if( v2>1 ){
-              sqlite3_snprintf(nTemp-jj, zTemp+jj, "..%d", v1+v2-1);
-            }
-          }else if( strncmp(zSynopsis+ii+1, "..P3", 4)==0 && pOp->p3==0 ){
-            ii += 4;
-          }
-        }
-        jj += sqlite3Strlen30(zTemp+jj);
-      }else{
-        zTemp[jj++] = c;
-      }
-    }
-    if( !seenCom && jj<nTemp-5 && pOp->zComment ){
-      sqlite3_snprintf(nTemp-jj, zTemp+jj, "; %s", pOp->zComment);
-      jj += sqlite3Strlen30(zTemp+jj);
-    }
-    if( jj<nTemp ) zTemp[jj] = 0;
-  }else if( pOp->zComment ){
-    sqlite3_snprintf(nTemp, zTemp, "%s", pOp->zComment);
-    jj = sqlite3Strlen30(zTemp);
-  }else{
-    zTemp[0] = 0;
-    jj = 0;
-  }
-  return jj;
-}
-#endif /* SQLITE_DEBUG */
-
-#if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
-/*
-** Translate the P4.pExpr value for an OP_CursorHint opcode into text
-** that can be displayed in the P4 column of EXPLAIN output.
-*/
-static int displayP4Expr(int nTemp, char *zTemp, Expr *pExpr){
-  const char *zOp = 0;
-  int n;
-  switch( pExpr->op ){
-    case TK_STRING:
-      sqlite3_snprintf(nTemp, zTemp, "%Q", pExpr->u.zToken);
-      break;
-    case TK_INTEGER:
-      sqlite3_snprintf(nTemp, zTemp, "%d", pExpr->u.iValue);
-      break;
-    case TK_NULL:
-      sqlite3_snprintf(nTemp, zTemp, "NULL");
-      break;
-    case TK_REGISTER: {
-      sqlite3_snprintf(nTemp, zTemp, "r[%d]", pExpr->iTable);
-      break;
-    }
-    case TK_COLUMN: {
-      if( pExpr->iColumn<0 ){
-        sqlite3_snprintf(nTemp, zTemp, "rowid");
-      }else{
-        sqlite3_snprintf(nTemp, zTemp, "c%d", (int)pExpr->iColumn);
-      }
-      break;
-    }
-    case TK_LT:      zOp = "LT";      break;
-    case TK_LE:      zOp = "LE";      break;
-    case TK_GT:      zOp = "GT";      break;
-    case TK_GE:      zOp = "GE";      break;
-    case TK_NE:      zOp = "NE";      break;
-    case TK_EQ:      zOp = "EQ";      break;
-    case TK_IS:      zOp = "IS";      break;
-    case TK_ISNOT:   zOp = "ISNOT";   break;
-    case TK_AND:     zOp = "AND";     break;
-    case TK_OR:      zOp = "OR";      break;
-    case TK_PLUS:    zOp = "ADD";     break;
-    case TK_STAR:    zOp = "MUL";     break;
-    case TK_MINUS:   zOp = "SUB";     break;
-    case TK_REM:     zOp = "REM";     break;
-    case TK_BITAND:  zOp = "BITAND";  break;
-    case TK_BITOR:   zOp = "BITOR";   break;
-    case TK_SLASH:   zOp = "DIV";     break;
-    case TK_LSHIFT:  zOp = "LSHIFT";  break;
-    case TK_RSHIFT:  zOp = "RSHIFT";  break;
-    case TK_CONCAT:  zOp = "CONCAT";  break;
-    case TK_UMINUS:  zOp = "MINUS";   break;
-    case TK_UPLUS:   zOp = "PLUS";    break;
-    case TK_BITNOT:  zOp = "BITNOT";  break;
-    case TK_NOT:     zOp = "NOT";     break;
-    case TK_ISNULL:  zOp = "ISNULL";  break;
-    case TK_NOTNULL: zOp = "NOTNULL"; break;
-
-    default:
-      sqlite3_snprintf(nTemp, zTemp, "%s", "expr");
-      break;
-  }
-
-  if( zOp ){
-    sqlite3_snprintf(nTemp, zTemp, "%s(", zOp);
-    n = sqlite3Strlen30(zTemp);
-    n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pLeft);
-    if( n<nTemp-1 && pExpr->pRight ){
-      zTemp[n++] = ',';
-      n += displayP4Expr(nTemp-n, zTemp+n, pExpr->pRight);
-    }
-    sqlite3_snprintf(nTemp-n, zTemp+n, ")");
-  }
-  return sqlite3Strlen30(zTemp);
-}
-#endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */
-
-
-#if VDBE_DISPLAY_P4
-/*
-** Compute a string that describes the P4 parameter for an opcode.
-** Use zTemp for any required temporary buffer space.
-*/
-static char *displayP4(Op *pOp, char *zTemp, int nTemp){
-  char *zP4 = zTemp;
-  assert( nTemp>=20 );
-  switch( pOp->p4type ){
-    case P4_KEYINFO: {
-      int i, j;
-      KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
-      assert( pKeyInfo->aSortOrder!=0 );
-      sqlite3_snprintf(nTemp, zTemp, "k(%d", pKeyInfo->nField);
-      i = sqlite3Strlen30(zTemp);
-      for(j=0; j<pKeyInfo->nField; j++){
-        CollSeq *pColl = pKeyInfo->aColl[j];
-        const char *zColl = pColl ? pColl->zName : "nil";
-        int n = sqlite3Strlen30(zColl);
-        if( n==6 && memcmp(zColl,"BINARY",6)==0 ){
-          zColl = "B";
-          n = 1;
-        }
-        if( i+n>nTemp-7 ){
-          memcpy(&zTemp[i],",...",4);
-          i += 4;
-          break;
-        }
-        zTemp[i++] = ',';
-        if( pKeyInfo->aSortOrder[j] ){
-          zTemp[i++] = '-';
-        }
-        memcpy(&zTemp[i], zColl, n+1);
-        i += n;
-      }
-      zTemp[i++] = ')';
-      zTemp[i] = 0;
-      assert( i<nTemp );
-      break;
-    }
-#ifdef SQLITE_ENABLE_CURSOR_HINTS
-    case P4_EXPR: {
-      displayP4Expr(nTemp, zTemp, pOp->p4.pExpr);
-      break;
-    }
-#endif
-    case P4_COLLSEQ: {
-      CollSeq *pColl = pOp->p4.pColl;
-      sqlite3_snprintf(nTemp, zTemp, "(%.20s)", pColl->zName);
-      break;
-    }
-    case P4_FUNCDEF: {
-      FuncDef *pDef = pOp->p4.pFunc;
-      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
-      break;
-    }
-#ifdef SQLITE_DEBUG
-    case P4_FUNCCTX: {
-      FuncDef *pDef = pOp->p4.pCtx->pFunc;
-      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
-      break;
-    }
-#endif
-    case P4_INT64: {
-      sqlite3_snprintf(nTemp, zTemp, "%lld", *pOp->p4.pI64);
-      break;
-    }
-    case P4_INT32: {
-      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
-      break;
-    }
-    case P4_REAL: {
-      sqlite3_snprintf(nTemp, zTemp, "%.16g", *pOp->p4.pReal);
-      break;
-    }
-    case P4_MEM: {
-      Mem *pMem = pOp->p4.pMem;
-      if( pMem->flags & MEM_Str ){
-        zP4 = pMem->z;
-      }else if( pMem->flags & MEM_Int ){
-        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
-      }else if( pMem->flags & MEM_Real ){
-        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->u.r);
-      }else if( pMem->flags & MEM_Null ){
-        sqlite3_snprintf(nTemp, zTemp, "NULL");
-      }else{
-        assert( pMem->flags & MEM_Blob );
-        zP4 = "(blob)";
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    case P4_VTAB: {
-      sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;
-      sqlite3_snprintf(nTemp, zTemp, "vtab:%p", pVtab);
-      break;
-    }
-#endif
-    case P4_INTARRAY: {
-      sqlite3_snprintf(nTemp, zTemp, "intarray");
-      break;
-    }
-    case P4_SUBPROGRAM: {
-      sqlite3_snprintf(nTemp, zTemp, "program");
-      break;
-    }
-    case P4_ADVANCE: {
-      zTemp[0] = 0;
-      break;
-    }
-    default: {
-      zP4 = pOp->p4.z;
-      if( zP4==0 ){
-        zP4 = zTemp;
-        zTemp[0] = 0;
-      }
-    }
-  }
-  assert( zP4!=0 );
-  return zP4;
-}
-#endif /* VDBE_DISPLAY_P4 */
-
-/*
-** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
-**
-** The prepared statements need to know in advance the complete set of
-** attached databases that will be use.  A mask of these databases
-** is maintained in p->btreeMask.  The p->lockMask value is the subset of
-** p->btreeMask of databases that will require a lock.
-*/
-void sqlite3VdbeUsesBtree(Vdbe *p, int i){
-  assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 );
-  assert( i<(int)sizeof(p->btreeMask)*8 );
-  DbMaskSet(p->btreeMask, i);
-  if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){
-    DbMaskSet(p->lockMask, i);
-  }
-}
-
-#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
-/*
-** If SQLite is compiled to support shared-cache mode and to be threadsafe,
-** this routine obtains the mutex associated with each BtShared structure
-** that may be accessed by the VM passed as an argument. In doing so it also
-** sets the BtShared.db member of each of the BtShared structures, ensuring
-** that the correct busy-handler callback is invoked if required.
-**
-** If SQLite is not threadsafe but does support shared-cache mode, then
-** sqlite3BtreeEnter() is invoked to set the BtShared.db variables
-** of all of BtShared structures accessible via the database handle 
-** associated with the VM.
-**
-** If SQLite is not threadsafe and does not support shared-cache mode, this
-** function is a no-op.
-**
-** The p->btreeMask field is a bitmask of all btrees that the prepared 
-** statement p will ever use.  Let N be the number of bits in p->btreeMask
-** corresponding to btrees that use shared cache.  Then the runtime of
-** this routine is N*N.  But as N is rarely more than 1, this should not
-** be a problem.
-*/
-void sqlite3VdbeEnter(Vdbe *p){
-  int i;
-  sqlite3 *db;
-  Db *aDb;
-  int nDb;
-  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
-  db = p->db;
-  aDb = db->aDb;
-  nDb = db->nDb;
-  for(i=0; i<nDb; i++){
-    if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
-      sqlite3BtreeEnter(aDb[i].pBt);
-    }
-  }
-}
-#endif
-
-#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
-/*
-** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().
-*/
-static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){
-  int i;
-  sqlite3 *db;
-  Db *aDb;
-  int nDb;
-  db = p->db;
-  aDb = db->aDb;
-  nDb = db->nDb;
-  for(i=0; i<nDb; i++){
-    if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
-      sqlite3BtreeLeave(aDb[i].pBt);
-    }
-  }
-}
-void sqlite3VdbeLeave(Vdbe *p){
-  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
-  vdbeLeave(p);
-}
-#endif
-
-#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
-/*
-** Print a single opcode.  This routine is used for debugging only.
-*/
-void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
-  char *zP4;
-  char zPtr[50];
-  char zCom[100];
-  static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";
-  if( pOut==0 ) pOut = stdout;
-  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-  displayComment(pOp, zP4, zCom, sizeof(zCom));
-#else
-  zCom[0] = 0;
-#endif
-  /* NB:  The sqlite3OpcodeName() function is implemented by code created
-  ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the
-  ** information from the vdbe.c source text */
-  fprintf(pOut, zFormat1, pc, 
-      sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
-      zCom
-  );
-  fflush(pOut);
-}
-#endif
-
-/*
-** Release an array of N Mem elements
-*/
-static void releaseMemArray(Mem *p, int N){
-  if( p && N ){
-    Mem *pEnd = &p[N];
-    sqlite3 *db = p->db;
-    u8 malloc_failed = db->mallocFailed;
-    if( db->pnBytesFreed ){
-      do{
-        if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
-      }while( (++p)<pEnd );
-      return;
-    }
-    do{
-      assert( (&p[1])==pEnd || p[0].db==p[1].db );
-      assert( sqlite3VdbeCheckMemInvariants(p) );
-
-      /* This block is really an inlined version of sqlite3VdbeMemRelease()
-      ** that takes advantage of the fact that the memory cell value is 
-      ** being set to NULL after releasing any dynamic resources.
-      **
-      ** The justification for duplicating code is that according to 
-      ** callgrind, this causes a certain test case to hit the CPU 4.7 
-      ** percent less (x86 linux, gcc version 4.1.2, -O6) than if 
-      ** sqlite3MemRelease() were called from here. With -O2, this jumps
-      ** to 6.6 percent. The test case is inserting 1000 rows into a table 
-      ** with no indexes using a single prepared INSERT statement, bind() 
-      ** and reset(). Inserts are grouped into a transaction.
-      */
-      testcase( p->flags & MEM_Agg );
-      testcase( p->flags & MEM_Dyn );
-      testcase( p->flags & MEM_Frame );
-      testcase( p->flags & MEM_RowSet );
-      if( p->flags&(MEM_Agg|MEM_Dyn|MEM_Frame|MEM_RowSet) ){
-        sqlite3VdbeMemRelease(p);
-      }else if( p->szMalloc ){
-        sqlite3DbFree(db, p->zMalloc);
-        p->szMalloc = 0;
-      }
-
-      p->flags = MEM_Undefined;
-    }while( (++p)<pEnd );
-    db->mallocFailed = malloc_failed;
-  }
-}
-
-/*
-** Delete a VdbeFrame object and its contents. VdbeFrame objects are
-** allocated by the OP_Program opcode in sqlite3VdbeExec().
-*/
-void sqlite3VdbeFrameDelete(VdbeFrame *p){
-  int i;
-  Mem *aMem = VdbeFrameMem(p);
-  VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];
-  for(i=0; i<p->nChildCsr; i++){
-    sqlite3VdbeFreeCursor(p->v, apCsr[i]);
-  }
-  releaseMemArray(aMem, p->nChildMem);
-  sqlite3DbFree(p->v->db, p);
-}
-
-#ifndef SQLITE_OMIT_EXPLAIN
-/*
-** Give a listing of the program in the virtual machine.
-**
-** The interface is the same as sqlite3VdbeExec().  But instead of
-** running the code, it invokes the callback once for each instruction.
-** This feature is used to implement "EXPLAIN".
-**
-** When p->explain==1, each instruction is listed.  When
-** p->explain==2, only OP_Explain instructions are listed and these
-** are shown in a different format.  p->explain==2 is used to implement
-** EXPLAIN QUERY PLAN.
-**
-** When p->explain==1, first the main program is listed, then each of
-** the trigger subprograms are listed one by one.
-*/
-int sqlite3VdbeList(
-  Vdbe *p                   /* The VDBE */
-){
-  int nRow;                            /* Stop when row count reaches this */
-  int nSub = 0;                        /* Number of sub-vdbes seen so far */
-  SubProgram **apSub = 0;              /* Array of sub-vdbes */
-  Mem *pSub = 0;                       /* Memory cell hold array of subprogs */
-  sqlite3 *db = p->db;                 /* The database connection */
-  int i;                               /* Loop counter */
-  int rc = SQLITE_OK;                  /* Return code */
-  Mem *pMem = &p->aMem[1];             /* First Mem of result set */
-
-  assert( p->explain );
-  assert( p->magic==VDBE_MAGIC_RUN );
-  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY || p->rc==SQLITE_NOMEM );
-
-  /* Even though this opcode does not use dynamic strings for
-  ** the result, result columns may become dynamic if the user calls
-  ** sqlite3_column_text16(), causing a translation to UTF-16 encoding.
-  */
-  releaseMemArray(pMem, 8);
-  p->pResultSet = 0;
-
-  if( p->rc==SQLITE_NOMEM ){
-    /* This happens if a malloc() inside a call to sqlite3_column_text() or
-    ** sqlite3_column_text16() failed.  */
-    db->mallocFailed = 1;
-    return SQLITE_ERROR;
-  }
-
-  /* When the number of output rows reaches nRow, that means the
-  ** listing has finished and sqlite3_step() should return SQLITE_DONE.
-  ** nRow is the sum of the number of rows in the main program, plus
-  ** the sum of the number of rows in all trigger subprograms encountered
-  ** so far.  The nRow value will increase as new trigger subprograms are
-  ** encountered, but p->pc will eventually catch up to nRow.
-  */
-  nRow = p->nOp;
-  if( p->explain==1 ){
-    /* The first 8 memory cells are used for the result set.  So we will
-    ** commandeer the 9th cell to use as storage for an array of pointers
-    ** to trigger subprograms.  The VDBE is guaranteed to have at least 9
-    ** cells.  */
-    assert( p->nMem>9 );
-    pSub = &p->aMem[9];
-    if( pSub->flags&MEM_Blob ){
-      /* On the first call to sqlite3_step(), pSub will hold a NULL.  It is
-      ** initialized to a BLOB by the P4_SUBPROGRAM processing logic below */
-      nSub = pSub->n/sizeof(Vdbe*);
-      apSub = (SubProgram **)pSub->z;
-    }
-    for(i=0; i<nSub; i++){
-      nRow += apSub[i]->nOp;
-    }
-  }
-
-  do{
-    i = p->pc++;
-  }while( i<nRow && p->explain==2 && p->aOp[i].opcode!=OP_Explain );
-  if( i>=nRow ){
-    p->rc = SQLITE_OK;
-    rc = SQLITE_DONE;
-  }else if( db->u1.isInterrupted ){
-    p->rc = SQLITE_INTERRUPT;
-    rc = SQLITE_ERROR;
-    sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
-  }else{
-    char *zP4;
-    Op *pOp;
-    if( i<p->nOp ){
-      /* The output line number is small enough that we are still in the
-      ** main program. */
-      pOp = &p->aOp[i];
-    }else{
-      /* We are currently listing subprograms.  Figure out which one and
-      ** pick up the appropriate opcode. */
-      int j;
-      i -= p->nOp;
-      for(j=0; i>=apSub[j]->nOp; j++){
-        i -= apSub[j]->nOp;
-      }
-      pOp = &apSub[j]->aOp[i];
-    }
-    if( p->explain==1 ){
-      pMem->flags = MEM_Int;
-      pMem->u.i = i;                                /* Program counter */
-      pMem++;
-  
-      pMem->flags = MEM_Static|MEM_Str|MEM_Term;
-      pMem->z = (char*)sqlite3OpcodeName(pOp->opcode); /* Opcode */
-      assert( pMem->z!=0 );
-      pMem->n = sqlite3Strlen30(pMem->z);
-      pMem->enc = SQLITE_UTF8;
-      pMem++;
-
-      /* When an OP_Program opcode is encounter (the only opcode that has
-      ** a P4_SUBPROGRAM argument), expand the size of the array of subprograms
-      ** kept in p->aMem[9].z to hold the new program - assuming this subprogram
-      ** has not already been seen.
-      */
-      if( pOp->p4type==P4_SUBPROGRAM ){
-        int nByte = (nSub+1)*sizeof(SubProgram*);
-        int j;
-        for(j=0; j<nSub; j++){
-          if( apSub[j]==pOp->p4.pProgram ) break;
-        }
-        if( j==nSub && SQLITE_OK==sqlite3VdbeMemGrow(pSub, nByte, nSub!=0) ){
-          apSub = (SubProgram **)pSub->z;
-          apSub[nSub++] = pOp->p4.pProgram;
-          pSub->flags |= MEM_Blob;
-          pSub->n = nSub*sizeof(SubProgram*);
-        }
-      }
-    }
-
-    pMem->flags = MEM_Int;
-    pMem->u.i = pOp->p1;                          /* P1 */
-    pMem++;
-
-    pMem->flags = MEM_Int;
-    pMem->u.i = pOp->p2;                          /* P2 */
-    pMem++;
-
-    pMem->flags = MEM_Int;
-    pMem->u.i = pOp->p3;                          /* P3 */
-    pMem++;
-
-    if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
-      assert( p->db->mallocFailed );
-      return SQLITE_ERROR;
-    }
-    pMem->flags = MEM_Str|MEM_Term;
-    zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
-    if( zP4!=pMem->z ){
-      sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
-    }else{
-      assert( pMem->z!=0 );
-      pMem->n = sqlite3Strlen30(pMem->z);
-      pMem->enc = SQLITE_UTF8;
-    }
-    pMem++;
-
-    if( p->explain==1 ){
-      if( sqlite3VdbeMemClearAndResize(pMem, 4) ){
-        assert( p->db->mallocFailed );
-        return SQLITE_ERROR;
-      }
-      pMem->flags = MEM_Str|MEM_Term;
-      pMem->n = 2;
-      sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5);   /* P5 */
-      pMem->enc = SQLITE_UTF8;
-      pMem++;
-  
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-      if( sqlite3VdbeMemClearAndResize(pMem, 500) ){
-        assert( p->db->mallocFailed );
-        return SQLITE_ERROR;
-      }
-      pMem->flags = MEM_Str|MEM_Term;
-      pMem->n = displayComment(pOp, zP4, pMem->z, 500);
-      pMem->enc = SQLITE_UTF8;
-#else
-      pMem->flags = MEM_Null;                       /* Comment */
-#endif
-    }
-
-    p->nResColumn = 8 - 4*(p->explain-1);
-    p->pResultSet = &p->aMem[1];
-    p->rc = SQLITE_OK;
-    rc = SQLITE_ROW;
-  }
-  return rc;
-}
-#endif /* SQLITE_OMIT_EXPLAIN */
-
-#ifdef SQLITE_DEBUG
-/*
-** Print the SQL that was used to generate a VDBE program.
-*/
-void sqlite3VdbePrintSql(Vdbe *p){
-  const char *z = 0;
-  if( p->zSql ){
-    z = p->zSql;
-  }else if( p->nOp>=1 ){
-    const VdbeOp *pOp = &p->aOp[0];
-    if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
-      z = pOp->p4.z;
-      while( sqlite3Isspace(*z) ) z++;
-    }
-  }
-  if( z ) printf("SQL: [%s]\n", z);
-}
-#endif
-
-#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
-/*
-** Print an IOTRACE message showing SQL content.
-*/
-void sqlite3VdbeIOTraceSql(Vdbe *p){
-  int nOp = p->nOp;
-  VdbeOp *pOp;
-  if( sqlite3IoTrace==0 ) return;
-  if( nOp<1 ) return;
-  pOp = &p->aOp[0];
-  if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
-    int i, j;
-    char z[1000];
-    sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.z);
-    for(i=0; sqlite3Isspace(z[i]); i++){}
-    for(j=0; z[i]; i++){
-      if( sqlite3Isspace(z[i]) ){
-        if( z[i-1]!=' ' ){
-          z[j++] = ' ';
-        }
-      }else{
-        z[j++] = z[i];
-      }
-    }
-    z[j] = 0;
-    sqlite3IoTrace("SQL %s\n", z);
-  }
-}
-#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */
-
-/*
-** Allocate space from a fixed size buffer and return a pointer to
-** that space.  If insufficient space is available, return NULL.
-**
-** The pBuf parameter is the initial value of a pointer which will
-** receive the new memory.  pBuf is normally NULL.  If pBuf is not
-** NULL, it means that memory space has already been allocated and that
-** this routine should not allocate any new memory.  When pBuf is not
-** NULL simply return pBuf.  Only allocate new memory space when pBuf
-** is NULL.
-**
-** nByte is the number of bytes of space needed.
-**
-** pFrom points to *pnFrom bytes of available space.  New space is allocated
-** from the end of the pFrom buffer and *pnFrom is decremented.
-**
-** *pnNeeded is a counter of the number of bytes of space that have failed
-** to allocate.  If there is insufficient space in pFrom to satisfy the
-** request, then increment *pnNeeded by the amount of the request.
-*/
-static void *allocSpace(
-  void *pBuf,          /* Where return pointer will be stored */
-  int nByte,           /* Number of bytes to allocate */
-  u8 *pFrom,           /* Memory available for allocation */
-  int *pnFrom,         /* IN/OUT: Space available at pFrom */
-  int *pnNeeded        /* If allocation cannot be made, increment *pnByte */
-){
-  assert( EIGHT_BYTE_ALIGNMENT(pFrom) );
-  if( pBuf==0 ){
-    nByte = ROUND8(nByte);
-    if( nByte <= *pnFrom ){
-      *pnFrom -= nByte;
-      pBuf = &pFrom[*pnFrom];
-    }else{
-      *pnNeeded += nByte;
-    }
-  }
-  assert( EIGHT_BYTE_ALIGNMENT(pBuf) );
-  return pBuf;
-}
-
-/*
-** Rewind the VDBE back to the beginning in preparation for
-** running it.
-*/
-void sqlite3VdbeRewind(Vdbe *p){
-#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
-  int i;
-#endif
-  assert( p!=0 );
-  assert( p->magic==VDBE_MAGIC_INIT );
-
-  /* There should be at least one opcode.
-  */
-  assert( p->nOp>0 );
-
-  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */
-  p->magic = VDBE_MAGIC_RUN;
-
-#ifdef SQLITE_DEBUG
-  for(i=1; i<p->nMem; i++){
-    assert( p->aMem[i].db==p->db );
-  }
-#endif
-  p->pc = -1;
-  p->rc = SQLITE_OK;
-  p->errorAction = OE_Abort;
-  p->magic = VDBE_MAGIC_RUN;
-  p->nChange = 0;
-  p->cacheCtr = 1;
-  p->minWriteFileFormat = 255;
-  p->iStatement = 0;
-  p->nFkConstraint = 0;
-#ifdef VDBE_PROFILE
-  for(i=0; i<p->nOp; i++){
-    p->aOp[i].cnt = 0;
-    p->aOp[i].cycles = 0;
-  }
-#endif
-}
-
-/*
-** Prepare a virtual machine for execution for the first time after
-** creating the virtual machine.  This involves things such
-** as allocating registers and initializing the program counter.
-** After the VDBE has be prepped, it can be executed by one or more
-** calls to sqlite3VdbeExec().  
-**
-** This function may be called exactly once on each virtual machine.
-** After this routine is called the VM has been "packaged" and is ready
-** to run.  After this routine is called, further calls to 
-** sqlite3VdbeAddOp() functions are prohibited.  This routine disconnects
-** the Vdbe from the Parse object that helped generate it so that the
-** the Vdbe becomes an independent entity and the Parse object can be
-** destroyed.
-**
-** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back
-** to its initial state after it has been run.
-*/
-void sqlite3VdbeMakeReady(
-  Vdbe *p,                       /* The VDBE */
-  Parse *pParse                  /* Parsing context */
-){
-  sqlite3 *db;                   /* The database connection */
-  int nVar;                      /* Number of parameters */
-  int nMem;                      /* Number of VM memory registers */
-  int nCursor;                   /* Number of cursors required */
-  int nArg;                      /* Number of arguments in subprograms */
-  int nOnce;                     /* Number of OP_Once instructions */
-  int n;                         /* Loop counter */
-  int nFree;                     /* Available free space */
-  u8 *zCsr;                      /* Memory available for allocation */
-  int nByte;                     /* How much extra memory is needed */
-
-  assert( p!=0 );
-  assert( p->nOp>0 );
-  assert( pParse!=0 );
-  assert( p->magic==VDBE_MAGIC_INIT );
-  assert( pParse==p->pParse );
-  db = p->db;
-  assert( db->mallocFailed==0 );
-  nVar = pParse->nVar;
-  nMem = pParse->nMem;
-  nCursor = pParse->nTab;
-  nArg = pParse->nMaxArg;
-  nOnce = pParse->nOnce;
-  if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
-  
-  /* For each cursor required, also allocate a memory cell. Memory
-  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
-  ** the vdbe program. Instead they are used to allocate space for
-  ** VdbeCursor/BtCursor structures. The blob of memory associated with 
-  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
-  ** stores the blob of memory associated with cursor 1, etc.
-  **
-  ** See also: allocateCursor().
-  */
-  nMem += nCursor;
-
-  /* zCsr will initially point to nFree bytes of unused space at the
-  ** end of the opcode array, p->aOp.  The computation of nFree is
-  ** conservative - it might be smaller than the true number of free
-  ** bytes, but never larger.  nFree must be a multiple of 8 - it is
-  ** rounded down if is not.
-  */
-  n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode space used */
-  zCsr = &((u8*)p->aOp)[n];                   /* Unused opcode space */
-  assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
-  nFree = ROUNDDOWN8(pParse->szOpAlloc - n);  /* Bytes of unused space */
-  assert( nFree>=0 );
-  if( nFree>0 ){
-    memset(zCsr, 0, nFree);
-    assert( EIGHT_BYTE_ALIGNMENT(&zCsr[nFree]) );
-  }
-
-  resolveP2Values(p, &nArg);
-  p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
-  if( pParse->explain && nMem<10 ){
-    nMem = 10;
-  }
-  p->expired = 0;
-
-  /* Memory for registers, parameters, cursor, etc, is allocated in two
-  ** passes.  On the first pass, we try to reuse unused space at the 
-  ** end of the opcode array.  If we are unable to satisfy all memory
-  ** requirements by reusing the opcode array tail, then the second
-  ** pass will fill in the rest using a fresh allocation.  
-  **
-  ** This two-pass approach that reuses as much memory as possible from
-  ** the leftover space at the end of the opcode array can significantly
-  ** reduce the amount of memory held by a prepared statement.
-  */
-  do {
-    nByte = 0;
-    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), zCsr, &nFree, &nByte);
-    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), zCsr, &nFree, &nByte);
-    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), zCsr, &nFree, &nByte);
-    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), zCsr, &nFree, &nByte);
-    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
-                          zCsr, &nFree, &nByte);
-    p->aOnceFlag = allocSpace(p->aOnceFlag, nOnce, zCsr, &nFree, &nByte);
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-    p->anExec = allocSpace(p->anExec, p->nOp*sizeof(i64), zCsr, &nFree, &nByte);
-#endif
-    if( nByte ){
-      p->pFree = sqlite3DbMallocZero(db, nByte);
-    }
-    zCsr = p->pFree;
-    nFree = nByte;
-  }while( nByte && !db->mallocFailed );
-
-  p->nCursor = nCursor;
-  p->nOnceFlag = nOnce;
-  if( p->aVar ){
-    p->nVar = (ynVar)nVar;
-    for(n=0; n<nVar; n++){
-      p->aVar[n].flags = MEM_Null;
-      p->aVar[n].db = db;
-    }
-  }
-  if( p->azVar && pParse->nzVar>0 ){
-    p->nzVar = pParse->nzVar;
-    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
-    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
-  }
-  if( p->aMem ){
-    p->aMem--;                      /* aMem[] goes from 1..nMem */
-    p->nMem = nMem;                 /*       not from 0..nMem-1 */
-    for(n=1; n<=nMem; n++){
-      p->aMem[n].flags = MEM_Undefined;
-      p->aMem[n].db = db;
-    }
-  }
-  p->explain = pParse->explain;
-  sqlite3VdbeRewind(p);
-}
-
-/*
-** Close a VDBE cursor and release all the resources that cursor 
-** happens to hold.
-*/
-void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
-  if( pCx==0 ){
-    return;
-  }
-  assert( pCx->pBt==0 || pCx->eCurType==CURTYPE_BTREE );
-  switch( pCx->eCurType ){
-    case CURTYPE_SORTER: {
-      sqlite3VdbeSorterClose(p->db, pCx);
-      break;
-    }
-    case CURTYPE_BTREE: {
-      if( pCx->pBt ){
-        sqlite3BtreeClose(pCx->pBt);
-        /* The pCx->pCursor will be close automatically, if it exists, by
-        ** the call above. */
-      }else{
-        assert( pCx->uc.pCursor!=0 );
-        sqlite3BtreeCloseCursor(pCx->uc.pCursor);
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-    case CURTYPE_VTAB: {
-      sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;
-      const sqlite3_module *pModule = pVCur->pVtab->pModule;
-      assert( pVCur->pVtab->nRef>0 );
-      pVCur->pVtab->nRef--;
-      pModule->xClose(pVCur);
-      break;
-    }
-#endif
-  }
-}
-
-/*
-** Close all cursors in the current frame.
-*/
-static void closeCursorsInFrame(Vdbe *p){
-  if( p->apCsr ){
-    int i;
-    for(i=0; i<p->nCursor; i++){
-      VdbeCursor *pC = p->apCsr[i];
-      if( pC ){
-        sqlite3VdbeFreeCursor(p, pC);
-        p->apCsr[i] = 0;
-      }
-    }
-  }
-}
-
-/*
-** Copy the values stored in the VdbeFrame structure to its Vdbe. This
-** is used, for example, when a trigger sub-program is halted to restore
-** control to the main program.
-*/
-int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
-  Vdbe *v = pFrame->v;
-  closeCursorsInFrame(v);
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-  v->anExec = pFrame->anExec;
-#endif
-  v->aOnceFlag = pFrame->aOnceFlag;
-  v->nOnceFlag = pFrame->nOnceFlag;
-  v->aOp = pFrame->aOp;
-  v->nOp = pFrame->nOp;
-  v->aMem = pFrame->aMem;
-  v->nMem = pFrame->nMem;
-  v->apCsr = pFrame->apCsr;
-  v->nCursor = pFrame->nCursor;
-  v->db->lastRowid = pFrame->lastRowid;
-  v->nChange = pFrame->nChange;
-  v->db->nChange = pFrame->nDbChange;
-  return pFrame->pc;
-}
-
-/*
-** Close all cursors.
-**
-** Also release any dynamic memory held by the VM in the Vdbe.aMem memory 
-** cell array. This is necessary as the memory cell array may contain
-** pointers to VdbeFrame objects, which may in turn contain pointers to
-** open cursors.
-*/
-static void closeAllCursors(Vdbe *p){
-  if( p->pFrame ){
-    VdbeFrame *pFrame;
-    for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
-    sqlite3VdbeFrameRestore(pFrame);
-    p->pFrame = 0;
-    p->nFrame = 0;
-  }
-  assert( p->nFrame==0 );
-  closeCursorsInFrame(p);
-  if( p->aMem ){
-    releaseMemArray(&p->aMem[1], p->nMem);
-  }
-  while( p->pDelFrame ){
-    VdbeFrame *pDel = p->pDelFrame;
-    p->pDelFrame = pDel->pParent;
-    sqlite3VdbeFrameDelete(pDel);
-  }
-
-  /* Delete any auxdata allocations made by the VM */
-  if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p, -1, 0);
-  assert( p->pAuxData==0 );
-}
-
-/*
-** Clean up the VM after a single run.
-*/
-static void Cleanup(Vdbe *p){
-  sqlite3 *db = p->db;
-
-#ifdef SQLITE_DEBUG
-  /* Execute assert() statements to ensure that the Vdbe.apCsr[] and 
-  ** Vdbe.aMem[] arrays have already been cleaned up.  */
-  int i;
-  if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );
-  if( p->aMem ){
-    for(i=1; i<=p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
-  }
-#endif
-
-  sqlite3DbFree(db, p->zErrMsg);
-  p->zErrMsg = 0;
-  p->pResultSet = 0;
-}
-
-/*
-** Set the number of result columns that will be returned by this SQL
-** statement. This is now set at compile time, rather than during
-** execution of the vdbe program so that sqlite3_column_count() can
-** be called on an SQL statement before sqlite3_step().
-*/
-void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){
-  Mem *pColName;
-  int n;
-  sqlite3 *db = p->db;
-
-  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
-  sqlite3DbFree(db, p->aColName);
-  n = nResColumn*COLNAME_N;
-  p->nResColumn = (u16)nResColumn;
-  p->aColName = pColName = (Mem*)sqlite3DbMallocZero(db, sizeof(Mem)*n );
-  if( p->aColName==0 ) return;
-  while( n-- > 0 ){
-    pColName->flags = MEM_Null;
-    pColName->db = p->db;
-    pColName++;
-  }
-}
-
-/*
-** Set the name of the idx'th column to be returned by the SQL statement.
-** zName must be a pointer to a nul terminated string.
-**
-** This call must be made after a call to sqlite3VdbeSetNumCols().
-**
-** The final parameter, xDel, must be one of SQLITE_DYNAMIC, SQLITE_STATIC
-** or SQLITE_TRANSIENT. If it is SQLITE_DYNAMIC, then the buffer pointed
-** to by zName will be freed by sqlite3DbFree() when the vdbe is destroyed.
-*/
-int sqlite3VdbeSetColName(
-  Vdbe *p,                         /* Vdbe being configured */
-  int idx,                         /* Index of column zName applies to */
-  int var,                         /* One of the COLNAME_* constants */
-  const char *zName,               /* Pointer to buffer containing name */
-  void (*xDel)(void*)              /* Memory management strategy for zName */
-){
-  int rc;
-  Mem *pColName;
-  assert( idx<p->nResColumn );
-  assert( var<COLNAME_N );
-  if( p->db->mallocFailed ){
-    assert( !zName || xDel!=SQLITE_DYNAMIC );
-    return SQLITE_NOMEM;
-  }
-  assert( p->aColName!=0 );
-  pColName = &(p->aColName[idx+var*p->nResColumn]);
-  rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, xDel);
-  assert( rc!=0 || !zName || (pColName->flags&MEM_Term)!=0 );
-  return rc;
-}
-
-/*
-** A read or write transaction may or may not be active on database handle
-** db. If a transaction is active, commit it. If there is a
-** write-transaction spanning more than one database file, this routine
-** takes care of the master journal trickery.
-*/
-static int vdbeCommit(sqlite3 *db, Vdbe *p){
-  int i;
-  int nTrans = 0;  /* Number of databases with an active write-transaction */
-  int rc = SQLITE_OK;
-  int needXcommit = 0;
-
-#ifdef SQLITE_OMIT_VIRTUALTABLE
-  /* With this option, sqlite3VtabSync() is defined to be simply 
-  ** SQLITE_OK so p is not used. 
-  */
-  UNUSED_PARAMETER(p);
-#endif
-
-  /* Before doing anything else, call the xSync() callback for any
-  ** virtual module tables written in this transaction. This has to
-  ** be done before determining whether a master journal file is 
-  ** required, as an xSync() callback may add an attached database
-  ** to the transaction.
-  */
-  rc = sqlite3VtabSync(db, p);
-
-  /* This loop determines (a) if the commit hook should be invoked and
-  ** (b) how many database files have open write transactions, not 
-  ** including the temp database. (b) is important because if more than 
-  ** one database file has an open write transaction, a master journal
-  ** file is required for an atomic commit.
-  */ 
-  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
-    Btree *pBt = db->aDb[i].pBt;
-    if( sqlite3BtreeIsInTrans(pBt) ){
-      needXcommit = 1;
-      if( i!=1 ) nTrans++;
-      sqlite3BtreeEnter(pBt);
-      rc = sqlite3PagerExclusiveLock(sqlite3BtreePager(pBt));
-      sqlite3BtreeLeave(pBt);
-    }
-  }
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
-
-  /* If there are any write-transactions at all, invoke the commit hook */
-  if( needXcommit && db->xCommitCallback ){
-    rc = db->xCommitCallback(db->pCommitArg);
-    if( rc ){
-      return SQLITE_CONSTRAINT_COMMITHOOK;
-    }
-  }
-
-  /* The simple case - no more than one database file (not counting the
-  ** TEMP database) has a transaction active.   There is no need for the
-  ** master-journal.
-  **
-  ** If the return value of sqlite3BtreeGetFilename() is a zero length
-  ** string, it means the main database is :memory: or a temp file.  In 
-  ** that case we do not support atomic multi-file commits, so use the 
-  ** simple case then too.
-  */
-  if( 0==sqlite3Strlen30(sqlite3BtreeGetFilename(db->aDb[0].pBt))
-   || nTrans<=1
-  ){
-    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        rc = sqlite3BtreeCommitPhaseOne(pBt, 0);
-      }
-    }
-
-    /* Do the commit only if all databases successfully complete phase 1. 
-    ** If one of the BtreeCommitPhaseOne() calls fails, this indicates an
-    ** IO error while deleting or truncating a journal file. It is unlikely,
-    ** but could happen. In this case abandon processing and return the error.
-    */
-    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        rc = sqlite3BtreeCommitPhaseTwo(pBt, 0);
-      }
-    }
-    if( rc==SQLITE_OK ){
-      sqlite3VtabCommit(db);
-    }
-  }
-
-  /* The complex case - There is a multi-file write-transaction active.
-  ** This requires a master journal file to ensure the transaction is
-  ** committed atomically.
-  */
-#ifndef SQLITE_OMIT_DISKIO
-  else{
-    sqlite3_vfs *pVfs = db->pVfs;
-    int needSync = 0;
-    char *zMaster = 0;   /* File-name for the master journal */
-    char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
-    sqlite3_file *pMaster = 0;
-    i64 offset = 0;
-    int res;
-    int retryCount = 0;
-    int nMainFile;
-
-    /* Select a master journal file name */
-    nMainFile = sqlite3Strlen30(zMainFile);
-    zMaster = sqlite3MPrintf(db, "%s-mjXXXXXX9XXz", zMainFile);
-    if( zMaster==0 ) return SQLITE_NOMEM;
-    do {
-      u32 iRandom;
-      if( retryCount ){
-        if( retryCount>100 ){
-          sqlite3_log(SQLITE_FULL, "MJ delete: %s", zMaster);
-          sqlite3OsDelete(pVfs, zMaster, 0);
-          break;
-        }else if( retryCount==1 ){
-          sqlite3_log(SQLITE_FULL, "MJ collide: %s", zMaster);
-        }
-      }
-      retryCount++;
-      sqlite3_randomness(sizeof(iRandom), &iRandom);
-      sqlite3_snprintf(13, &zMaster[nMainFile], "-mj%06X9%02X",
-                               (iRandom>>8)&0xffffff, iRandom&0xff);
-      /* The antipenultimate character of the master journal name must
-      ** be "9" to avoid name collisions when using 8+3 filenames. */
-      assert( zMaster[sqlite3Strlen30(zMaster)-3]=='9' );
-      sqlite3FileSuffix3(zMainFile, zMaster);
-      rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);
-    }while( rc==SQLITE_OK && res );
-    if( rc==SQLITE_OK ){
-      /* Open the master journal. */
-      rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 
-          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
-          SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
-      );
-    }
-    if( rc!=SQLITE_OK ){
-      sqlite3DbFree(db, zMaster);
-      return rc;
-    }
- 
-    /* Write the name of each database file in the transaction into the new
-    ** master journal file. If an error occurs at this point close
-    ** and delete the master journal file. All the individual journal files
-    ** still have 'null' as the master journal pointer, so they will roll
-    ** back independently if a failure occurs.
-    */
-    for(i=0; i<db->nDb; i++){
-      Btree *pBt = db->aDb[i].pBt;
-      if( sqlite3BtreeIsInTrans(pBt) ){
-        char const *zFile = sqlite3BtreeGetJournalname(pBt);
-        if( zFile==0 ){
-          continue;  /* Ignore TEMP and :memory: databases */
-        }
-        assert( zFile[0]!=0 );
-        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
-          needSync = 1;
-        }
-        rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
-        offset += sqlite3Strlen30(zFile)+1;
-        if( rc!=SQLITE_OK ){
-          sqlite3OsCloseFree(pMaster);
-          sqlite3OsDelete(pVfs, zMaster, 0);
-          sqlite3DbFree(db, zMaster);
-          return rc;
-        }
-      }
-    }
-
-    /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
-    ** flag is set this is not required.
-    */
-    if( needSync 
-     && 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
-     && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))
-    ){
-      sqlite3OsCloseFree(pMaster);
-      sqlite3OsDelete(pVfs, zMaster, 0);
-      sqlite3DbFree(db, zMaster);
-      return rc;
-    }
-
-    /* Sync all the db files involved in the transaction. The same call
-    ** sets the master journal pointer in each individual journal. If
-    ** an error occurs here, do not delete the master journal file.
-    **
-    ** If the error occurs during the first call to
-    ** sqlite3BtreeCommitPhaseOne(), then there is a chance that the
-    ** master journal file will be orphaned. But we cannot delete it,
-    ** in case the master journal file name was written into the journal
-    ** file before the failure occurred.
-    */
-    for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        rc = sqlite3BtreeCommitPhaseOne(pBt, zMaster);
-      }
-    }
-    sqlite3OsCloseFree(pMaster);
-    assert( rc!=SQLITE_BUSY );
-    if( rc!=SQLITE_OK ){
-      sqlite3DbFree(db, zMaster);
-      return rc;
-    }
-
-    /* Delete the master journal file. This commits the transaction. After
-    ** doing this the directory is synced again before any individual
-    ** transaction files are deleted.
-    */
-    rc = sqlite3OsDelete(pVfs, zMaster, needSync);
-    sqlite3DbFree(db, zMaster);
-    zMaster = 0;
-    if( rc ){
-      return rc;
-    }
-
-    /* All files and directories have already been synced, so the following
-    ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and
-    ** deleting or truncating journals. If something goes wrong while
-    ** this is happening we don't really care. The integrity of the
-    ** transaction is already guaranteed, but some stray 'cold' journals
-    ** may be lying around. Returning an error code won't help matters.
-    */
-    disable_simulated_io_errors();
-    sqlite3BeginBenignMalloc();
-    for(i=0; i<db->nDb; i++){ 
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        sqlite3BtreeCommitPhaseTwo(pBt, 1);
-      }
-    }
-    sqlite3EndBenignMalloc();
-    enable_simulated_io_errors();
-
-    sqlite3VtabCommit(db);
-  }
-#endif
-
-  return rc;
-}
-
-/* 
-** This routine checks that the sqlite3.nVdbeActive count variable
-** matches the number of vdbe's in the list sqlite3.pVdbe that are
-** currently active. An assertion fails if the two counts do not match.
-** This is an internal self-check only - it is not an essential processing
-** step.
-**
-** This is a no-op if NDEBUG is defined.
-*/
-#ifndef NDEBUG
-static void checkActiveVdbeCnt(sqlite3 *db){
-  Vdbe *p;
-  int cnt = 0;
-  int nWrite = 0;
-  int nRead = 0;
-  p = db->pVdbe;
-  while( p ){
-    if( sqlite3_stmt_busy((sqlite3_stmt*)p) ){
-      cnt++;
-      if( p->readOnly==0 ) nWrite++;
-      if( p->bIsReader ) nRead++;
-    }
-    p = p->pNext;
-  }
-  assert( cnt==db->nVdbeActive );
-  assert( nWrite==db->nVdbeWrite );
-  assert( nRead==db->nVdbeRead );
-}
-#else
-#define checkActiveVdbeCnt(x)
-#endif
-
-/*
-** If the Vdbe passed as the first argument opened a statement-transaction,
-** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
-** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
-** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
-** statement transaction is committed.
-**
-** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
-** Otherwise SQLITE_OK.
-*/
-int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
-  sqlite3 *const db = p->db;
-  int rc = SQLITE_OK;
-
-  /* If p->iStatement is greater than zero, then this Vdbe opened a 
-  ** statement transaction that should be closed here. The only exception
-  ** is that an IO error may have occurred, causing an emergency rollback.
-  ** In this case (db->nStatement==0), and there is nothing to do.
-  */
-  if( db->nStatement && p->iStatement ){
-    int i;
-    const int iSavepoint = p->iStatement-1;
-
-    assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);
-    assert( db->nStatement>0 );
-    assert( p->iStatement==(db->nStatement+db->nSavepoint) );
-
-    for(i=0; i<db->nDb; i++){ 
-      int rc2 = SQLITE_OK;
-      Btree *pBt = db->aDb[i].pBt;
-      if( pBt ){
-        if( eOp==SAVEPOINT_ROLLBACK ){
-          rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_ROLLBACK, iSavepoint);
-        }
-        if( rc2==SQLITE_OK ){
-          rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_RELEASE, iSavepoint);
-        }
-        if( rc==SQLITE_OK ){
-          rc = rc2;
-        }
-      }
-    }
-    db->nStatement--;
-    p->iStatement = 0;
-
-    if( rc==SQLITE_OK ){
-      if( eOp==SAVEPOINT_ROLLBACK ){
-        rc = sqlite3VtabSavepoint(db, SAVEPOINT_ROLLBACK, iSavepoint);
-      }
-      if( rc==SQLITE_OK ){
-        rc = sqlite3VtabSavepoint(db, SAVEPOINT_RELEASE, iSavepoint);
-      }
-    }
-
-    /* If the statement transaction is being rolled back, also restore the 
-    ** database handles deferred constraint counter to the value it had when 
-    ** the statement transaction was opened.  */
-    if( eOp==SAVEPOINT_ROLLBACK ){
-      db->nDeferredCons = p->nStmtDefCons;
-      db->nDeferredImmCons = p->nStmtDefImmCons;
-    }
-  }
-  return rc;
-}
-
-/*
-** This function is called when a transaction opened by the database 
-** handle associated with the VM passed as an argument is about to be 
-** committed. If there are outstanding deferred foreign key constraint
-** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.
-**
-** If there are outstanding FK violations and this function returns 
-** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY
-** and write an error message to it. Then return SQLITE_ERROR.
-*/
-#ifndef SQLITE_OMIT_FOREIGN_KEY
-int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
-  sqlite3 *db = p->db;
-  if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0) 
-   || (!deferred && p->nFkConstraint>0) 
-  ){
-    p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
-    p->errorAction = OE_Abort;
-    sqlite3VdbeError(p, "FOREIGN KEY constraint failed");
-    return SQLITE_ERROR;
-  }
-  return SQLITE_OK;
-}
-#endif
-
-/*
-** This routine is called the when a VDBE tries to halt.  If the VDBE
-** has made changes and is in autocommit mode, then commit those
-** changes.  If a rollback is needed, then do the rollback.
-**
-** This routine is the only way to move the state of a VM from
-** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT.  It is harmless to
-** call this on a VM that is in the SQLITE_MAGIC_HALT state.
-**
-** Return an error code.  If the commit could not complete because of
-** lock contention, return SQLITE_BUSY.  If SQLITE_BUSY is returned, it
-** means the close did not happen and needs to be repeated.
-*/
-int sqlite3VdbeHalt(Vdbe *p){
-  int rc;                         /* Used to store transient return codes */
-  sqlite3 *db = p->db;
-
-  /* This function contains the logic that determines if a statement or
-  ** transaction will be committed or rolled back as a result of the
-  ** execution of this virtual machine. 
-  **
-  ** If any of the following errors occur:
-  **
-  **     SQLITE_NOMEM
-  **     SQLITE_IOERR
-  **     SQLITE_FULL
-  **     SQLITE_INTERRUPT
-  **
-  ** Then the internal cache might have been left in an inconsistent
-  ** state.  We need to rollback the statement transaction, if there is
-  ** one, or the complete transaction if there is no statement transaction.
-  */
-
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
-  }
-  if( p->aOnceFlag ) memset(p->aOnceFlag, 0, p->nOnceFlag);
-  closeAllCursors(p);
-  if( p->magic!=VDBE_MAGIC_RUN ){
-    return SQLITE_OK;
-  }
-  checkActiveVdbeCnt(db);
-
-  /* No commit or rollback needed if the program never started or if the
-  ** SQL statement does not read or write a database file.  */
-  if( p->pc>=0 && p->bIsReader ){
-    int mrc;   /* Primary error code from p->rc */
-    int eStatementOp = 0;
-    int isSpecialError;            /* Set to true if a 'special' error */
-
-    /* Lock all btrees used by the statement */
-    sqlite3VdbeEnter(p);
-
-    /* Check for one of the special errors */
-    mrc = p->rc & 0xff;
-    isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
-                     || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;
-    if( isSpecialError ){
-      /* If the query was read-only and the error code is SQLITE_INTERRUPT, 
-      ** no rollback is necessary. Otherwise, at least a savepoint 
-      ** transaction must be rolled back to restore the database to a 
-      ** consistent state.
-      **
-      ** Even if the statement is read-only, it is important to perform
-      ** a statement or transaction rollback operation. If the error 
-      ** occurred while writing to the journal, sub-journal or database
-      ** file as part of an effort to free up cache space (see function
-      ** pagerStress() in pager.c), the rollback is required to restore 
-      ** the pager to a consistent state.
-      */
-      if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){
-        if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){
-          eStatementOp = SAVEPOINT_ROLLBACK;
-        }else{
-          /* We are forced to roll back the active transaction. Before doing
-          ** so, abort any other statements this handle currently has active.
-          */
-          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
-          sqlite3CloseSavepoints(db);
-          db->autoCommit = 1;
-          p->nChange = 0;
-        }
-      }
-    }
-
-    /* Check for immediate foreign key violations. */
-    if( p->rc==SQLITE_OK ){
-      sqlite3VdbeCheckFk(p, 0);
-    }
-  
-    /* If the auto-commit flag is set and this is the only active writer 
-    ** VM, then we do either a commit or rollback of the current transaction. 
-    **
-    ** Note: This block also runs if one of the special errors handled 
-    ** above has occurred. 
-    */
-    if( !sqlite3VtabInSync(db) 
-     && db->autoCommit 
-     && db->nVdbeWrite==(p->readOnly==0) 
-    ){
-      if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
-        rc = sqlite3VdbeCheckFk(p, 1);
-        if( rc!=SQLITE_OK ){
-          if( NEVER(p->readOnly) ){
-            sqlite3VdbeLeave(p);
-            return SQLITE_ERROR;
-          }
-          rc = SQLITE_CONSTRAINT_FOREIGNKEY;
-        }else{ 
-          /* The auto-commit flag is true, the vdbe program was successful 
-          ** or hit an 'OR FAIL' constraint and there are no deferred foreign
-          ** key constraints to hold up the transaction. This means a commit 
-          ** is required. */
-          rc = vdbeCommit(db, p);
-        }
-        if( rc==SQLITE_BUSY && p->readOnly ){
-          sqlite3VdbeLeave(p);
-          return SQLITE_BUSY;
-        }else if( rc!=SQLITE_OK ){
-          p->rc = rc;
-          sqlite3RollbackAll(db, SQLITE_OK);
-          p->nChange = 0;
-        }else{
-          db->nDeferredCons = 0;
-          db->nDeferredImmCons = 0;
-          db->flags &= ~SQLITE_DeferFKs;
-          sqlite3CommitInternalChanges(db);
-        }
-      }else{
-        sqlite3RollbackAll(db, SQLITE_OK);
-        p->nChange = 0;
-      }
-      db->nStatement = 0;
-    }else if( eStatementOp==0 ){
-      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
-        eStatementOp = SAVEPOINT_RELEASE;
-      }else if( p->errorAction==OE_Abort ){
-        eStatementOp = SAVEPOINT_ROLLBACK;
-      }else{
-        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
-        sqlite3CloseSavepoints(db);
-        db->autoCommit = 1;
-        p->nChange = 0;
-      }
-    }
-  
-    /* If eStatementOp is non-zero, then a statement transaction needs to
-    ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
-    ** do so. If this operation returns an error, and the current statement
-    ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the
-    ** current statement error code.
-    */
-    if( eStatementOp ){
-      rc = sqlite3VdbeCloseStatement(p, eStatementOp);
-      if( rc ){
-        if( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT ){
-          p->rc = rc;
-          sqlite3DbFree(db, p->zErrMsg);
-          p->zErrMsg = 0;
-        }
-        sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
-        sqlite3CloseSavepoints(db);
-        db->autoCommit = 1;
-        p->nChange = 0;
-      }
-    }
-  
-    /* If this was an INSERT, UPDATE or DELETE and no statement transaction
-    ** has been rolled back, update the database connection change-counter. 
-    */
-    if( p->changeCntOn ){
-      if( eStatementOp!=SAVEPOINT_ROLLBACK ){
-        sqlite3VdbeSetChanges(db, p->nChange);
-      }else{
-        sqlite3VdbeSetChanges(db, 0);
-      }
-      p->nChange = 0;
-    }
-
-    /* Release the locks */
-    sqlite3VdbeLeave(p);
-  }
-
-  /* We have successfully halted and closed the VM.  Record this fact. */
-  if( p->pc>=0 ){
-    db->nVdbeActive--;
-    if( !p->readOnly ) db->nVdbeWrite--;
-    if( p->bIsReader ) db->nVdbeRead--;
-    assert( db->nVdbeActive>=db->nVdbeRead );
-    assert( db->nVdbeRead>=db->nVdbeWrite );
-    assert( db->nVdbeWrite>=0 );
-  }
-  p->magic = VDBE_MAGIC_HALT;
-  checkActiveVdbeCnt(db);
-  if( p->db->mallocFailed ){
-    p->rc = SQLITE_NOMEM;
-  }
-
-  /* If the auto-commit flag is set to true, then any locks that were held
-  ** by connection db have now been released. Call sqlite3ConnectionUnlocked() 
-  ** to invoke any required unlock-notify callbacks.
-  */
-  if( db->autoCommit ){
-    sqlite3ConnectionUnlocked(db);
-  }
-
-  assert( db->nVdbeActive>0 || db->autoCommit==0 || db->nStatement==0 );
-  return (p->rc==SQLITE_BUSY ? SQLITE_BUSY : SQLITE_OK);
-}
-
-
-/*
-** Each VDBE holds the result of the most recent sqlite3_step() call
-** in p->rc.  This routine sets that result back to SQLITE_OK.
-*/
-void sqlite3VdbeResetStepResult(Vdbe *p){
-  p->rc = SQLITE_OK;
-}
-
-/*
-** Copy the error code and error message belonging to the VDBE passed
-** as the first argument to its database handle (so that they will be 
-** returned by calls to sqlite3_errcode() and sqlite3_errmsg()).
-**
-** This function does not clear the VDBE error code or message, just
-** copies them to the database handle.
-*/
-int sqlite3VdbeTransferError(Vdbe *p){
-  sqlite3 *db = p->db;
-  int rc = p->rc;
-  if( p->zErrMsg ){
-    u8 mallocFailed = db->mallocFailed;
-    sqlite3BeginBenignMalloc();
-    if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
-    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
-    sqlite3EndBenignMalloc();
-    db->mallocFailed = mallocFailed;
-    db->errCode = rc;
-  }else{
-    sqlite3Error(db, rc);
-  }
-  return rc;
-}
-
-#ifdef SQLITE_ENABLE_SQLLOG
-/*
-** If an SQLITE_CONFIG_SQLLOG hook is registered and the VM has been run, 
-** invoke it.
-*/
-static void vdbeInvokeSqllog(Vdbe *v){
-  if( sqlite3GlobalConfig.xSqllog && v->rc==SQLITE_OK && v->zSql && v->pc>=0 ){
-    char *zExpanded = sqlite3VdbeExpandSql(v, v->zSql);
-    assert( v->db->init.busy==0 );
-    if( zExpanded ){
-      sqlite3GlobalConfig.xSqllog(
-          sqlite3GlobalConfig.pSqllogArg, v->db, zExpanded, 1
-      );
-      sqlite3DbFree(v->db, zExpanded);
-    }
-  }
-}
-#else
-# define vdbeInvokeSqllog(x)
-#endif
-
-/*
-** Clean up a VDBE after execution but do not delete the VDBE just yet.
-** Write any error messages into *pzErrMsg.  Return the result code.
-**
-** After this routine is run, the VDBE should be ready to be executed
-** again.
-**
-** To look at it another way, this routine resets the state of the
-** virtual machine from VDBE_MAGIC_RUN or VDBE_MAGIC_HALT back to
-** VDBE_MAGIC_INIT.
-*/
-int sqlite3VdbeReset(Vdbe *p){
-  sqlite3 *db;
-  db = p->db;
-
-  /* If the VM did not run to completion or if it encountered an
-  ** error, then it might not have been halted properly.  So halt
-  ** it now.
-  */
-  sqlite3VdbeHalt(p);
-
-  /* If the VDBE has be run even partially, then transfer the error code
-  ** and error message from the VDBE into the main database structure.  But
-  ** if the VDBE has just been set to run but has not actually executed any
-  ** instructions yet, leave the main database error information unchanged.
-  */
-  if( p->pc>=0 ){
-    vdbeInvokeSqllog(p);
-    sqlite3VdbeTransferError(p);
-    sqlite3DbFree(db, p->zErrMsg);
-    p->zErrMsg = 0;
-    if( p->runOnlyOnce ) p->expired = 1;
-  }else if( p->rc && p->expired ){
-    /* The expired flag was set on the VDBE before the first call
-    ** to sqlite3_step(). For consistency (since sqlite3_step() was
-    ** called), set the database error in this case as well.
-    */
-    sqlite3ErrorWithMsg(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
-    sqlite3DbFree(db, p->zErrMsg);
-    p->zErrMsg = 0;
-  }
-
-  /* Reclaim all memory used by the VDBE
-  */
-  Cleanup(p);
-
-  /* Save profiling information from this VDBE run.
-  */
-#ifdef VDBE_PROFILE
-  {
-    FILE *out = fopen("vdbe_profile.out", "a");
-    if( out ){
-      int i;
-      fprintf(out, "---- ");
-      for(i=0; i<p->nOp; i++){
-        fprintf(out, "%02x", p->aOp[i].opcode);
-      }
-      fprintf(out, "\n");
-      if( p->zSql ){
-        char c, pc = 0;
-        fprintf(out, "-- ");
-        for(i=0; (c = p->zSql[i])!=0; i++){
-          if( pc=='\n' ) fprintf(out, "-- ");
-          putc(c, out);
-          pc = c;
-        }
-        if( pc!='\n' ) fprintf(out, "\n");
-      }
-      for(i=0; i<p->nOp; i++){
-        char zHdr[100];
-        sqlite3_snprintf(sizeof(zHdr), zHdr, "%6u %12llu %8llu ",
-           p->aOp[i].cnt,
-           p->aOp[i].cycles,
-           p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
-        );
-        fprintf(out, "%s", zHdr);
-        sqlite3VdbePrintOp(out, i, &p->aOp[i]);
-      }
-      fclose(out);
-    }
-  }
-#endif
-  p->iCurrentTime = 0;
-  p->magic = VDBE_MAGIC_INIT;
-  return p->rc & db->errMask;
-}
- 
-/*
-** Clean up and delete a VDBE after execution.  Return an integer which is
-** the result code.  Write any error message text into *pzErrMsg.
-*/
-int sqlite3VdbeFinalize(Vdbe *p){
-  int rc = SQLITE_OK;
-  if( p->magic==VDBE_MAGIC_RUN || p->magic==VDBE_MAGIC_HALT ){
-    rc = sqlite3VdbeReset(p);
-    assert( (rc & p->db->errMask)==rc );
-  }
-  sqlite3VdbeDelete(p);
-  return rc;
-}
-
-/*
-** If parameter iOp is less than zero, then invoke the destructor for
-** all auxiliary data pointers currently cached by the VM passed as
-** the first argument.
-**
-** Or, if iOp is greater than or equal to zero, then the destructor is
-** only invoked for those auxiliary data pointers created by the user 
-** function invoked by the OP_Function opcode at instruction iOp of 
-** VM pVdbe, and only then if:
-**
-**    * the associated function parameter is the 32nd or later (counting
-**      from left to right), or
-**
-**    * the corresponding bit in argument mask is clear (where the first
-**      function parameter corresponds to bit 0 etc.).
-*/
-void sqlite3VdbeDeleteAuxData(Vdbe *pVdbe, int iOp, int mask){
-  AuxData **pp = &pVdbe->pAuxData;
-  while( *pp ){
-    AuxData *pAux = *pp;
-    if( (iOp<0)
-     || (pAux->iOp==iOp && (pAux->iArg>31 || !(mask & MASKBIT32(pAux->iArg))))
-    ){
-      testcase( pAux->iArg==31 );
-      if( pAux->xDelete ){
-        pAux->xDelete(pAux->pAux);
-      }
-      *pp = pAux->pNext;
-      sqlite3DbFree(pVdbe->db, pAux);
-    }else{
-      pp= &pAux->pNext;
-    }
-  }
-}
-
-/*
-** Free all memory associated with the Vdbe passed as the second argument,
-** except for object itself, which is preserved.
-**
-** The difference between this function and sqlite3VdbeDelete() is that
-** VdbeDelete() also unlinks the Vdbe from the list of VMs associated with
-** the database connection and frees the object itself.
-*/
-void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
-  SubProgram *pSub, *pNext;
-  int i;
-  assert( p->db==0 || p->db==db );
-  releaseMemArray(p->aVar, p->nVar);
-  releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
-  for(pSub=p->pProgram; pSub; pSub=pNext){
-    pNext = pSub->pNext;
-    vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
-    sqlite3DbFree(db, pSub);
-  }
-  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
-  vdbeFreeOpArray(db, p->aOp, p->nOp);
-  sqlite3DbFree(db, p->aColName);
-  sqlite3DbFree(db, p->zSql);
-  sqlite3DbFree(db, p->pFree);
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-  for(i=0; i<p->nScan; i++){
-    sqlite3DbFree(db, p->aScan[i].zName);
-  }
-  sqlite3DbFree(db, p->aScan);
-#endif
-}
-
-/*
-** Delete an entire VDBE.
-*/
-void sqlite3VdbeDelete(Vdbe *p){
-  sqlite3 *db;
-
-  if( NEVER(p==0) ) return;
-  db = p->db;
-  assert( sqlite3_mutex_held(db->mutex) );
-  sqlite3VdbeClearObject(db, p);
-  if( p->pPrev ){
-    p->pPrev->pNext = p->pNext;
-  }else{
-    assert( db->pVdbe==p );
-    db->pVdbe = p->pNext;
-  }
-  if( p->pNext ){
-    p->pNext->pPrev = p->pPrev;
-  }
-  p->magic = VDBE_MAGIC_DEAD;
-  p->db = 0;
-  sqlite3DbFree(db, p);
-}
-
-/*
-** The cursor "p" has a pending seek operation that has not yet been
-** carried out.  Seek the cursor now.  If an error occurs, return
-** the appropriate error code.
-*/
-static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
-  int res, rc;
-#ifdef SQLITE_TEST
-  extern int sqlite3_search_count;
-#endif
-  assert( p->deferredMoveto );
-  assert( p->isTable );
-  assert( p->eCurType==CURTYPE_BTREE );
-  rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);
-  if( rc ) return rc;
-  if( res!=0 ) return SQLITE_CORRUPT_BKPT;
-#ifdef SQLITE_TEST
-  sqlite3_search_count++;
-#endif
-  p->deferredMoveto = 0;
-  p->cacheStatus = CACHE_STALE;
-  return SQLITE_OK;
-}
-
-/*
-** Something has moved cursor "p" out of place.  Maybe the row it was
-** pointed to was deleted out from under it.  Or maybe the btree was
-** rebalanced.  Whatever the cause, try to restore "p" to the place it
-** is supposed to be pointing.  If the row was deleted out from under the
-** cursor, set the cursor to point to a NULL row.
-*/
-static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
-  int isDifferentRow, rc;
-  assert( p->eCurType==CURTYPE_BTREE );
-  assert( p->uc.pCursor!=0 );
-  assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );
-  rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);
-  p->cacheStatus = CACHE_STALE;
-  if( isDifferentRow ) p->nullRow = 1;
-  return rc;
-}
-
-/*
-** Check to ensure that the cursor is valid.  Restore the cursor
-** if need be.  Return any I/O error from the restore operation.
-*/
-int sqlite3VdbeCursorRestore(VdbeCursor *p){
-  assert( p->eCurType==CURTYPE_BTREE );
-  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
-    return handleMovedCursor(p);
-  }
-  return SQLITE_OK;
-}
-
-/*
-** Make sure the cursor p is ready to read or write the row to which it
-** was last positioned.  Return an error code if an OOM fault or I/O error
-** prevents us from positioning the cursor to its correct position.
-**
-** If a MoveTo operation is pending on the given cursor, then do that
-** MoveTo now.  If no move is pending, check to see if the row has been
-** deleted out from under the cursor and if it has, mark the row as
-** a NULL row.
-**
-** If the cursor is already pointing to the correct row and that row has
-** not been deleted out from under the cursor, then this routine is a no-op.
-*/
-int sqlite3VdbeCursorMoveto(VdbeCursor *p){
-  if( p->eCurType==CURTYPE_BTREE ){
-    if( p->deferredMoveto ){
-      return handleDeferredMoveto(p);
-    }
-    if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
-      return handleMovedCursor(p);
-    }
-  }
-  return SQLITE_OK;
-}
-
-/*
-** The following functions:
-**
-** sqlite3VdbeSerialType()
-** sqlite3VdbeSerialTypeLen()
-** sqlite3VdbeSerialLen()
-** sqlite3VdbeSerialPut()
-** sqlite3VdbeSerialGet()
-**
-** encapsulate the code that serializes values for storage in SQLite
-** data and index records. Each serialized value consists of a
-** 'serial-type' and a blob of data. The serial type is an 8-byte unsigned
-** integer, stored as a varint.
-**
-** In an SQLite index record, the serial type is stored directly before
-** the blob of data that it corresponds to. In a table record, all serial
-** types are stored at the start of the record, and the blobs of data at
-** the end. Hence these functions allow the caller to handle the
-** serial-type and data blob separately.
-**
-** The following table describes the various storage classes for data:
-**
-**   serial type        bytes of data      type
-**   --------------     ---------------    ---------------
-**      0                     0            NULL
-**      1                     1            signed integer
-**      2                     2            signed integer
-**      3                     3            signed integer
-**      4                     4            signed integer
-**      5                     6            signed integer
-**      6                     8            signed integer
-**      7                     8            IEEE float
-**      8                     0            Integer constant 0
-**      9                     0            Integer constant 1
-**     10,11                               reserved for expansion
-**    N>=12 and even       (N-12)/2        BLOB
-**    N>=13 and odd        (N-13)/2        text
-**
-** The 8 and 9 types were added in 3.3.0, file format 4.  Prior versions
-** of SQLite will not understand those serial types.
-*/
-
-/*
-** Return the serial-type for the value stored in pMem.
-*/
-u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
-  int flags = pMem->flags;
-  u32 n;
-
-  assert( pLen!=0 );
-  if( flags&MEM_Null ){
-    *pLen = 0;
-    return 0;
-  }
-  if( flags&MEM_Int ){
-    /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */
-#   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
-    i64 i = pMem->u.i;
-    u64 u;
-    if( i<0 ){
-      u = ~i;
-    }else{
-      u = i;
-    }
-    if( u<=127 ){
-      if( (i&1)==i && file_format>=4 ){
-        *pLen = 0;
-        return 8+(u32)u;
-      }else{
-        *pLen = 1;
-        return 1;
-      }
-    }
-    if( u<=32767 ){ *pLen = 2; return 2; }
-    if( u<=8388607 ){ *pLen = 3; return 3; }
-    if( u<=2147483647 ){ *pLen = 4; return 4; }
-    if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }
-    *pLen = 8;
-    return 6;
-  }
-  if( flags&MEM_Real ){
-    *pLen = 8;
-    return 7;
-  }
-  assert( pMem->db->mallocFailed || flags&(MEM_Str|MEM_Blob) );
-  assert( pMem->n>=0 );
-  n = (u32)pMem->n;
-  if( flags & MEM_Zero ){
-    n += pMem->u.nZero;
-  }
-  *pLen = n;
-  return ((n*2) + 12 + ((flags&MEM_Str)!=0));
-}
-
-/*
-** The sizes for serial types less than 128
-*/
-static const u8 sqlite3SmallTypeSizes[] = {
-        /*  0   1   2   3   4   5   6   7   8   9 */   
-/*   0 */   0,  1,  2,  3,  4,  6,  8,  8,  0,  0,
-/*  10 */   0,  0,  0,  0,  1,  1,  2,  2,  3,  3,
-/*  20 */   4,  4,  5,  5,  6,  6,  7,  7,  8,  8,
-/*  30 */   9,  9, 10, 10, 11, 11, 12, 12, 13, 13,
-/*  40 */  14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
-/*  50 */  19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
-/*  60 */  24, 24, 25, 25, 26, 26, 27, 27, 28, 28,
-/*  70 */  29, 29, 30, 30, 31, 31, 32, 32, 33, 33,
-/*  80 */  34, 34, 35, 35, 36, 36, 37, 37, 38, 38,
-/*  90 */  39, 39, 40, 40, 41, 41, 42, 42, 43, 43,
-/* 100 */  44, 44, 45, 45, 46, 46, 47, 47, 48, 48,
-/* 110 */  49, 49, 50, 50, 51, 51, 52, 52, 53, 53,
-/* 120 */  54, 54, 55, 55, 56, 56, 57, 57
-};
-
-/*
-** Return the length of the data corresponding to the supplied serial-type.
-*/
-u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
-  if( serial_type>=128 ){
-    return (serial_type-12)/2;
-  }else{
-    assert( serial_type<12 
-            || sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );
-    return sqlite3SmallTypeSizes[serial_type];
-  }
-}
-u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){
-  assert( serial_type<128 );
-  return sqlite3SmallTypeSizes[serial_type];  
-}
-
-/*
-** If we are on an architecture with mixed-endian floating 
-** points (ex: ARM7) then swap the lower 4 bytes with the 
-** upper 4 bytes.  Return the result.
-**
-** For most architectures, this is a no-op.
-**
-** (later):  It is reported to me that the mixed-endian problem
-** on ARM7 is an issue with GCC, not with the ARM7 chip.  It seems
-** that early versions of GCC stored the two words of a 64-bit
-** float in the wrong order.  And that error has been propagated
-** ever since.  The blame is not necessarily with GCC, though.
-** GCC might have just copying the problem from a prior compiler.
-** I am also told that newer versions of GCC that follow a different
-** ABI get the byte order right.
-**
-** Developers using SQLite on an ARM7 should compile and run their
-** application using -DSQLITE_DEBUG=1 at least once.  With DEBUG
-** enabled, some asserts below will ensure that the byte order of
-** floating point values is correct.
-**
-** (2007-08-30)  Frank van Vugt has studied this problem closely
-** and has send his findings to the SQLite developers.  Frank
-** writes that some Linux kernels offer floating point hardware
-** emulation that uses only 32-bit mantissas instead of a full 
-** 48-bits as required by the IEEE standard.  (This is the
-** CONFIG_FPE_FASTFPE option.)  On such systems, floating point
-** byte swapping becomes very complicated.  To avoid problems,
-** the necessary byte swapping is carried out using a 64-bit integer
-** rather than a 64-bit float.  Frank assures us that the code here
-** works for him.  We, the developers, have no way to independently
-** verify this, but Frank seems to know what he is talking about
-** so we trust him.
-*/
-#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
-static u64 floatSwap(u64 in){
-  union {
-    u64 r;
-    u32 i[2];
-  } u;
-  u32 t;
-
-  u.r = in;
-  t = u.i[0];
-  u.i[0] = u.i[1];
-  u.i[1] = t;
-  return u.r;
-}
-# define swapMixedEndianFloat(X)  X = floatSwap(X)
-#else
-# define swapMixedEndianFloat(X)
-#endif
-
-/*
-** Write the serialized data blob for the value stored in pMem into 
-** buf. It is assumed that the caller has allocated sufficient space.
-** Return the number of bytes written.
-**
-** nBuf is the amount of space left in buf[].  The caller is responsible
-** for allocating enough space to buf[] to hold the entire field, exclusive
-** of the pMem->u.nZero bytes for a MEM_Zero value.
-**
-** Return the number of bytes actually written into buf[].  The number
-** of bytes in the zero-filled tail is included in the return value only
-** if those bytes were zeroed in buf[].
-*/ 
-u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
-  u32 len;
-
-  /* Integer and Real */
-  if( serial_type<=7 && serial_type>0 ){
-    u64 v;
-    u32 i;
-    if( serial_type==7 ){
-      assert( sizeof(v)==sizeof(pMem->u.r) );
-      memcpy(&v, &pMem->u.r, sizeof(v));
-      swapMixedEndianFloat(v);
-    }else{
-      v = pMem->u.i;
-    }
-    len = i = sqlite3SmallTypeSizes[serial_type];
-    assert( i>0 );
-    do{
-      buf[--i] = (u8)(v&0xFF);
-      v >>= 8;
-    }while( i );
-    return len;
-  }
-
-  /* String or blob */
-  if( serial_type>=12 ){
-    assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
-             == (int)sqlite3VdbeSerialTypeLen(serial_type) );
-    len = pMem->n;
-    if( len>0 ) memcpy(buf, pMem->z, len);
-    return len;
-  }
-
-  /* NULL or constants 0 or 1 */
-  return 0;
-}
-
-/* Input "x" is a sequence of unsigned characters that represent a
-** big-endian integer.  Return the equivalent native integer
-*/
-#define ONE_BYTE_INT(x)    ((i8)(x)[0])
-#define TWO_BYTE_INT(x)    (256*(i8)((x)[0])|(x)[1])
-#define THREE_BYTE_INT(x)  (65536*(i8)((x)[0])|((x)[1]<<8)|(x)[2])
-#define FOUR_BYTE_UINT(x)  (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
-#define FOUR_BYTE_INT(x) (16777216*(i8)((x)[0])|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
-
-/*
-** Deserialize the data blob pointed to by buf as serial type serial_type
-** and store the result in pMem.  Return the number of bytes read.
-**
-** This function is implemented as two separate routines for performance.
-** The few cases that require local variables are broken out into a separate
-** routine so that in most cases the overhead of moving the stack pointer
-** is avoided.
-*/ 
-static u32 SQLITE_NOINLINE serialGet(
-  const unsigned char *buf,     /* Buffer to deserialize from */
-  u32 serial_type,              /* Serial type to deserialize */
-  Mem *pMem                     /* Memory cell to write value into */
-){
-  u64 x = FOUR_BYTE_UINT(buf);
-  u32 y = FOUR_BYTE_UINT(buf+4);
-  x = (x<<32) + y;
-  if( serial_type==6 ){
-    /* EVIDENCE-OF: R-29851-52272 Value is a big-endian 64-bit
-    ** twos-complement integer. */
-    pMem->u.i = *(i64*)&x;
-    pMem->flags = MEM_Int;
-    testcase( pMem->u.i<0 );
-  }else{
-    /* EVIDENCE-OF: R-57343-49114 Value is a big-endian IEEE 754-2008 64-bit
-    ** floating point number. */
-#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
-    /* Verify that integers and floating point values use the same
-    ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
-    ** defined that 64-bit floating point values really are mixed
-    ** endian.
-    */
-    static const u64 t1 = ((u64)0x3ff00000)<<32;
-    static const double r1 = 1.0;
-    u64 t2 = t1;
-    swapMixedEndianFloat(t2);
-    assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
-#endif
-    assert( sizeof(x)==8 && sizeof(pMem->u.r)==8 );
-    swapMixedEndianFloat(x);
-    memcpy(&pMem->u.r, &x, sizeof(x));
-    pMem->flags = sqlite3IsNaN(pMem->u.r) ? MEM_Null : MEM_Real;
-  }
-  return 8;
-}
-u32 sqlite3VdbeSerialGet(
-  const unsigned char *buf,     /* Buffer to deserialize from */
-  u32 serial_type,              /* Serial type to deserialize */
-  Mem *pMem                     /* Memory cell to write value into */
-){
-  switch( serial_type ){
-    case 10:   /* Reserved for future use */
-    case 11:   /* Reserved for future use */
-    case 0: {  /* Null */
-      /* EVIDENCE-OF: R-24078-09375 Value is a NULL. */
-      pMem->flags = MEM_Null;
-      break;
-    }
-    case 1: {
-      /* EVIDENCE-OF: R-44885-25196 Value is an 8-bit twos-complement
-      ** integer. */
-      pMem->u.i = ONE_BYTE_INT(buf);
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 1;
-    }
-    case 2: { /* 2-byte signed integer */
-      /* EVIDENCE-OF: R-49794-35026 Value is a big-endian 16-bit
-      ** twos-complement integer. */
-      pMem->u.i = TWO_BYTE_INT(buf);
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 2;
-    }
-    case 3: { /* 3-byte signed integer */
-      /* EVIDENCE-OF: R-37839-54301 Value is a big-endian 24-bit
-      ** twos-complement integer. */
-      pMem->u.i = THREE_BYTE_INT(buf);
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 3;
-    }
-    case 4: { /* 4-byte signed integer */
-      /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit
-      ** twos-complement integer. */
-      pMem->u.i = FOUR_BYTE_INT(buf);
-#ifdef __HP_cc 
-      /* Work around a sign-extension bug in the HP compiler for HP/UX */
-      if( buf[0]&0x80 ) pMem->u.i |= 0xffffffff80000000LL;
-#endif
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 4;
-    }
-    case 5: { /* 6-byte signed integer */
-      /* EVIDENCE-OF: R-50385-09674 Value is a big-endian 48-bit
-      ** twos-complement integer. */
-      pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 6;
-    }
-    case 6:   /* 8-byte signed integer */
-    case 7: { /* IEEE floating point */
-      /* These use local variables, so do them in a separate routine
-      ** to avoid having to move the frame pointer in the common case */
-      return serialGet(buf,serial_type,pMem);
-    }
-    case 8:    /* Integer 0 */
-    case 9: {  /* Integer 1 */
-      /* EVIDENCE-OF: R-12976-22893 Value is the integer 0. */
-      /* EVIDENCE-OF: R-18143-12121 Value is the integer 1. */
-      pMem->u.i = serial_type-8;
-      pMem->flags = MEM_Int;
-      return 0;
-    }
-    default: {
-      /* EVIDENCE-OF: R-14606-31564 Value is a BLOB that is (N-12)/2 bytes in
-      ** length.
-      ** EVIDENCE-OF: R-28401-00140 Value is a string in the text encoding and
-      ** (N-13)/2 bytes in length. */
-      static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
-      pMem->z = (char *)buf;
-      pMem->n = (serial_type-12)/2;
-      pMem->flags = aFlag[serial_type&1];
-      return pMem->n;
-    }
-  }
-  return 0;
-}
-/*
-** This routine is used to allocate sufficient space for an UnpackedRecord
-** structure large enough to be used with sqlite3VdbeRecordUnpack() if
-** the first argument is a pointer to KeyInfo structure pKeyInfo.
-**
-** The space is either allocated using sqlite3DbMallocRaw() or from within
-** the unaligned buffer passed via the second and third arguments (presumably
-** stack space). If the former, then *ppFree is set to a pointer that should
-** be eventually freed by the caller using sqlite3DbFree(). Or, if the 
-** allocation comes from the pSpace/szSpace buffer, *ppFree is set to NULL
-** before returning.
-**
-** If an OOM error occurs, NULL is returned.
-*/
-UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(
-  KeyInfo *pKeyInfo,              /* Description of the record */
-  char *pSpace,                   /* Unaligned space available */
-  int szSpace,                    /* Size of pSpace[] in bytes */
-  char **ppFree                   /* OUT: Caller should free this pointer */
-){
-  UnpackedRecord *p;              /* Unpacked record to return */
-  int nOff;                       /* Increment pSpace by nOff to align it */
-  int nByte;                      /* Number of bytes required for *p */
-
-  /* We want to shift the pointer pSpace up such that it is 8-byte aligned.
-  ** Thus, we need to calculate a value, nOff, between 0 and 7, to shift 
-  ** it by.  If pSpace is already 8-byte aligned, nOff should be zero.
-  */
-  nOff = (8 - (SQLITE_PTR_TO_INT(pSpace) & 7)) & 7;
-  nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
-  if( nByte>szSpace+nOff ){
-    p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
-    *ppFree = (char *)p;
-    if( !p ) return 0;
-  }else{
-    p = (UnpackedRecord*)&pSpace[nOff];
-    *ppFree = 0;
-  }
-
-  p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
-  assert( pKeyInfo->aSortOrder!=0 );
-  p->pKeyInfo = pKeyInfo;
-  p->nField = pKeyInfo->nField + 1;
-  return p;
-}
-
-/*
-** Given the nKey-byte encoding of a record in pKey[], populate the 
-** UnpackedRecord structure indicated by the fourth argument with the
-** contents of the decoded record.
-*/ 
-void sqlite3VdbeRecordUnpack(
-  KeyInfo *pKeyInfo,     /* Information about the record format */
-  int nKey,              /* Size of the binary record */
-  const void *pKey,      /* The binary record */
-  UnpackedRecord *p      /* Populate this structure before returning. */
-){
-  const unsigned char *aKey = (const unsigned char *)pKey;
-  int d; 
-  u32 idx;                        /* Offset in aKey[] to read from */
-  u16 u;                          /* Unsigned loop counter */
-  u32 szHdr;
-  Mem *pMem = p->aMem;
-
-  p->default_rc = 0;
-  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
-  idx = getVarint32(aKey, szHdr);
-  d = szHdr;
-  u = 0;
-  while( idx<szHdr && d<=nKey ){
-    u32 serial_type;
-
-    idx += getVarint32(&aKey[idx], serial_type);
-    pMem->enc = pKeyInfo->enc;
-    pMem->db = pKeyInfo->db;
-    /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
-    pMem->szMalloc = 0;
-    d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
-    pMem++;
-    if( (++u)>=p->nField ) break;
-  }
-  assert( u<=pKeyInfo->nField + 1 );
-  p->nField = u;
-}
-
-#if SQLITE_DEBUG
-/*
-** This function compares two index or table record keys in the same way
-** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),
-** this function deserializes and compares values using the
-** sqlite3VdbeSerialGet() and sqlite3MemCompare() functions. It is used
-** in assert() statements to ensure that the optimized code in
-** sqlite3VdbeRecordCompare() returns results with these two primitives.
-**
-** Return true if the result of comparison is equivalent to desiredResult.
-** Return false if there is a disagreement.
-*/
-static int vdbeRecordCompareDebug(
-  int nKey1, const void *pKey1, /* Left key */
-  const UnpackedRecord *pPKey2, /* Right key */
-  int desiredResult             /* Correct answer */
-){
-  u32 d1;            /* Offset into aKey[] of next data element */
-  u32 idx1;          /* Offset into aKey[] of next header element */
-  u32 szHdr1;        /* Number of bytes in header */
-  int i = 0;
-  int rc = 0;
-  const unsigned char *aKey1 = (const unsigned char *)pKey1;
-  KeyInfo *pKeyInfo;
-  Mem mem1;
-
-  pKeyInfo = pPKey2->pKeyInfo;
-  if( pKeyInfo->db==0 ) return 1;
-  mem1.enc = pKeyInfo->enc;
-  mem1.db = pKeyInfo->db;
-  /* mem1.flags = 0;  // Will be initialized by sqlite3VdbeSerialGet() */
-  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
-
-  /* Compilers may complain that mem1.u.i is potentially uninitialized.
-  ** We could initialize it, as shown here, to silence those complaints.
-  ** But in fact, mem1.u.i will never actually be used uninitialized, and doing 
-  ** the unnecessary initialization has a measurable negative performance
-  ** impact, since this routine is a very high runner.  And so, we choose
-  ** to ignore the compiler warnings and leave this variable uninitialized.
-  */
-  /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */
-  
-  idx1 = getVarint32(aKey1, szHdr1);
-  if( szHdr1>98307 ) return SQLITE_CORRUPT;
-  d1 = szHdr1;
-  assert( pKeyInfo->nField+pKeyInfo->nXField>=pPKey2->nField || CORRUPT_DB );
-  assert( pKeyInfo->aSortOrder!=0 );
-  assert( pKeyInfo->nField>0 );
-  assert( idx1<=szHdr1 || CORRUPT_DB );
-  do{
-    u32 serial_type1;
-
-    /* Read the serial types for the next element in each key. */
-    idx1 += getVarint32( aKey1+idx1, serial_type1 );
-
-    /* Verify that there is enough key space remaining to avoid
-    ** a buffer overread.  The "d1+serial_type1+2" subexpression will
-    ** always be greater than or equal to the amount of required key space.
-    ** Use that approximation to avoid the more expensive call to
-    ** sqlite3VdbeSerialTypeLen() in the common case.
-    */
-    if( d1+serial_type1+2>(u32)nKey1
-     && d1+sqlite3VdbeSerialTypeLen(serial_type1)>(u32)nKey1 
-    ){
-      break;
-    }
-
-    /* Extract the values to be compared.
-    */
-    d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);
-
-    /* Do the comparison
-    */
-    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i], pKeyInfo->aColl[i]);
-    if( rc!=0 ){
-      assert( mem1.szMalloc==0 );  /* See comment below */
-      if( pKeyInfo->aSortOrder[i] ){
-        rc = -rc;  /* Invert the result for DESC sort order. */
-      }
-      goto debugCompareEnd;
-    }
-    i++;
-  }while( idx1<szHdr1 && i<pPKey2->nField );
-
-  /* No memory allocation is ever used on mem1.  Prove this using
-  ** the following assert().  If the assert() fails, it indicates a
-  ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).
-  */
-  assert( mem1.szMalloc==0 );
-
-  /* rc==0 here means that one of the keys ran out of fields and
-  ** all the fields up to that point were equal. Return the default_rc
-  ** value.  */
-  rc = pPKey2->default_rc;
-
-debugCompareEnd:
-  if( desiredResult==0 && rc==0 ) return 1;
-  if( desiredResult<0 && rc<0 ) return 1;
-  if( desiredResult>0 && rc>0 ) return 1;
-  if( CORRUPT_DB ) return 1;
-  if( pKeyInfo->db->mallocFailed ) return 1;
-  return 0;
-}
-#endif
-
-#if SQLITE_DEBUG
-/*
-** Count the number of fields (a.k.a. columns) in the record given by
-** pKey,nKey.  The verify that this count is less than or equal to the
-** limit given by pKeyInfo->nField + pKeyInfo->nXField.
-**
-** If this constraint is not satisfied, it means that the high-speed
-** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will
-** not work correctly.  If this assert() ever fires, it probably means
-** that the KeyInfo.nField or KeyInfo.nXField values were computed
-** incorrectly.
-*/
-static void vdbeAssertFieldCountWithinLimits(
-  int nKey, const void *pKey,   /* The record to verify */ 
-  const KeyInfo *pKeyInfo       /* Compare size with this KeyInfo */
-){
-  int nField = 0;
-  u32 szHdr;
-  u32 idx;
-  u32 notUsed;
-  const unsigned char *aKey = (const unsigned char*)pKey;
-
-  if( CORRUPT_DB ) return;
-  idx = getVarint32(aKey, szHdr);
-  assert( nKey>=0 );
-  assert( szHdr<=(u32)nKey );
-  while( idx<szHdr ){
-    idx += getVarint32(aKey+idx, notUsed);
-    nField++;
-  }
-  assert( nField <= pKeyInfo->nField+pKeyInfo->nXField );
-}
-#else
-# define vdbeAssertFieldCountWithinLimits(A,B,C)
-#endif
-
-/*
-** Both *pMem1 and *pMem2 contain string values. Compare the two values
-** using the collation sequence pColl. As usual, return a negative , zero
-** or positive value if *pMem1 is less than, equal to or greater than 
-** *pMem2, respectively. Similar in spirit to "rc = (*pMem1) - (*pMem2);".
-*/
-static int vdbeCompareMemString(
-  const Mem *pMem1,
-  const Mem *pMem2,
-  const CollSeq *pColl,
-  u8 *prcErr                      /* If an OOM occurs, set to SQLITE_NOMEM */
-){
-  if( pMem1->enc==pColl->enc ){
-    /* The strings are already in the correct encoding.  Call the
-     ** comparison function directly */
-    return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
-  }else{
-    int rc;
-    const void *v1, *v2;
-    int n1, n2;
-    Mem c1;
-    Mem c2;
-    sqlite3VdbeMemInit(&c1, pMem1->db, MEM_Null);
-    sqlite3VdbeMemInit(&c2, pMem1->db, MEM_Null);
-    sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
-    sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
-    v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
-    n1 = v1==0 ? 0 : c1.n;
-    v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
-    n2 = v2==0 ? 0 : c2.n;
-    rc = pColl->xCmp(pColl->pUser, n1, v1, n2, v2);
-    sqlite3VdbeMemRelease(&c1);
-    sqlite3VdbeMemRelease(&c2);
-    if( (v1==0 || v2==0) && prcErr ) *prcErr = SQLITE_NOMEM;
-    return rc;
-  }
-}
-
-/*
-** Compare two blobs.  Return negative, zero, or positive if the first
-** is less than, equal to, or greater than the second, respectively.
-** If one blob is a prefix of the other, then the shorter is the lessor.
-*/
-static SQLITE_NOINLINE int sqlite3BlobCompare(const Mem *pB1, const Mem *pB2){
-  int c = memcmp(pB1->z, pB2->z, pB1->n>pB2->n ? pB2->n : pB1->n);
-  if( c ) return c;
-  return pB1->n - pB2->n;
-}
-
-/*
-** Do a comparison between a 64-bit signed integer and a 64-bit floating-point
-** number.  Return negative, zero, or positive if the first (i64) is less than,
-** equal to, or greater than the second (double).
-*/
-static int sqlite3IntFloatCompare(i64 i, double r){
-  if( sizeof(LONGDOUBLE_TYPE)>8 ){
-    LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
-    if( x<r ) return -1;
-    if( x>r ) return +1;
-    return 0;
-  }else{
-    i64 y;
-    double s;
-    if( r<-9223372036854775808.0 ) return +1;
-    if( r>9223372036854775807.0 ) return -1;
-    y = (i64)r;
-    if( i<y ) return -1;
-    if( i>y ){
-      if( y==SMALLEST_INT64 && r>0.0 ) return -1;
-      return +1;
-    }
-    s = (double)i;
-    if( s<r ) return -1;
-    if( s>r ) return +1;
-    return 0;
-  }
-}
-
-/*
-** Compare the values contained by the two memory cells, returning
-** negative, zero or positive if pMem1 is less than, equal to, or greater
-** than pMem2. Sorting order is NULL's first, followed by numbers (integers
-** and reals) sorted numerically, followed by text ordered by the collating
-** sequence pColl and finally blob's ordered by memcmp().
-**
-** Two NULL values are considered equal by this function.
-*/
-int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
-  int f1, f2;
-  int combined_flags;
-
-  f1 = pMem1->flags;
-  f2 = pMem2->flags;
-  combined_flags = f1|f2;
-  assert( (combined_flags & MEM_RowSet)==0 );
- 
-  /* If one value is NULL, it is less than the other. If both values
-  ** are NULL, return 0.
-  */
-  if( combined_flags&MEM_Null ){
-    return (f2&MEM_Null) - (f1&MEM_Null);
-  }
-
-  /* At least one of the two values is a number
-  */
-  if( combined_flags&(MEM_Int|MEM_Real) ){
-    if( (f1 & f2 & MEM_Int)!=0 ){
-      if( pMem1->u.i < pMem2->u.i ) return -1;
-      if( pMem1->u.i > pMem2->u.i ) return +1;
-      return 0;
-    }
-    if( (f1 & f2 & MEM_Real)!=0 ){
-      if( pMem1->u.r < pMem2->u.r ) return -1;
-      if( pMem1->u.r > pMem2->u.r ) return +1;
-      return 0;
-    }
-    if( (f1&MEM_Int)!=0 ){
-      if( (f2&MEM_Real)!=0 ){
-        return sqlite3IntFloatCompare(pMem1->u.i, pMem2->u.r);
-      }else{
-        return -1;
-      }
-    }
-    if( (f1&MEM_Real)!=0 ){
-      if( (f2&MEM_Int)!=0 ){
-        return -sqlite3IntFloatCompare(pMem2->u.i, pMem1->u.r);
-      }else{
-        return -1;
-      }
-    }
-    return +1;
-  }
-
-  /* If one value is a string and the other is a blob, the string is less.
-  ** If both are strings, compare using the collating functions.
-  */
-  if( combined_flags&MEM_Str ){
-    if( (f1 & MEM_Str)==0 ){
-      return 1;
-    }
-    if( (f2 & MEM_Str)==0 ){
-      return -1;
-    }
-
-    assert( pMem1->enc==pMem2->enc || pMem1->db->mallocFailed );
-    assert( pMem1->enc==SQLITE_UTF8 || 
-            pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
-
-    /* The collation sequence must be defined at this point, even if
-    ** the user deletes the collation sequence after the vdbe program is
-    ** compiled (this was not always the case).
-    */
-    assert( !pColl || pColl->xCmp );
-
-    if( pColl ){
-      return vdbeCompareMemString(pMem1, pMem2, pColl, 0);
-    }
-    /* If a NULL pointer was passed as the collate function, fall through
-    ** to the blob case and use memcmp().  */
-  }
- 
-  /* Both values must be blobs.  Compare using memcmp().  */
-  return sqlite3BlobCompare(pMem1, pMem2);
-}
-
-
-/*
-** The first argument passed to this function is a serial-type that
-** corresponds to an integer - all values between 1 and 9 inclusive 
-** except 7. The second points to a buffer containing an integer value
-** serialized according to serial_type. This function deserializes
-** and returns the value.
-*/
-static i64 vdbeRecordDecodeInt(u32 serial_type, const u8 *aKey){
-  u32 y;
-  assert( CORRUPT_DB || (serial_type>=1 && serial_type<=9 && serial_type!=7) );
-  switch( serial_type ){
-    case 0:
-    case 1:
-      testcase( aKey[0]&0x80 );
-      return ONE_BYTE_INT(aKey);
-    case 2:
-      testcase( aKey[0]&0x80 );
-      return TWO_BYTE_INT(aKey);
-    case 3:
-      testcase( aKey[0]&0x80 );
-      return THREE_BYTE_INT(aKey);
-    case 4: {
-      testcase( aKey[0]&0x80 );
-      y = FOUR_BYTE_UINT(aKey);
-      return (i64)*(int*)&y;
-    }
-    case 5: {
-      testcase( aKey[0]&0x80 );
-      return FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
-    }
-    case 6: {
-      u64 x = FOUR_BYTE_UINT(aKey);
-      testcase( aKey[0]&0x80 );
-      x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
-      return (i64)*(i64*)&x;
-    }
-  }
-
-  return (serial_type - 8);
-}
-
-/*
-** This function compares the two table rows or index records
-** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero
-** or positive integer if key1 is less than, equal to or 
-** greater than key2.  The {nKey1, pKey1} key must be a blob
-** created by the OP_MakeRecord opcode of the VDBE.  The pPKey2
-** key must be a parsed key such as obtained from
-** sqlite3VdbeParseRecord.
-**
-** If argument bSkip is non-zero, it is assumed that the caller has already
-** determined that the first fields of the keys are equal.
-**
-** Key1 and Key2 do not have to contain the same number of fields. If all 
-** fields that appear in both keys are equal, then pPKey2->default_rc is 
-** returned.
-**
-** If database corruption is discovered, set pPKey2->errCode to 
-** SQLITE_CORRUPT and return 0. If an OOM error is encountered, 
-** pPKey2->errCode is set to SQLITE_NOMEM and, if it is not NULL, the
-** malloc-failed flag set on database handle (pPKey2->pKeyInfo->db).
-*/
-int sqlite3VdbeRecordCompareWithSkip(
-  int nKey1, const void *pKey1,   /* Left key */
-  UnpackedRecord *pPKey2,         /* Right key */
-  int bSkip                       /* If true, skip the first field */
-){
-  u32 d1;                         /* Offset into aKey[] of next data element */
-  int i;                          /* Index of next field to compare */
-  u32 szHdr1;                     /* Size of record header in bytes */
-  u32 idx1;                       /* Offset of first type in header */
-  int rc = 0;                     /* Return value */
-  Mem *pRhs = pPKey2->aMem;       /* Next field of pPKey2 to compare */
-  KeyInfo *pKeyInfo = pPKey2->pKeyInfo;
-  const unsigned char *aKey1 = (const unsigned char *)pKey1;
-  Mem mem1;
-
-  /* If bSkip is true, then the caller has already determined that the first
-  ** two elements in the keys are equal. Fix the various stack variables so
-  ** that this routine begins comparing at the second field. */
-  if( bSkip ){
-    u32 s1;
-    idx1 = 1 + getVarint32(&aKey1[1], s1);
-    szHdr1 = aKey1[0];
-    d1 = szHdr1 + sqlite3VdbeSerialTypeLen(s1);
-    i = 1;
-    pRhs++;
-  }else{
-    idx1 = getVarint32(aKey1, szHdr1);
-    d1 = szHdr1;
-    if( d1>(unsigned)nKey1 ){ 
-      pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
-      return 0;  /* Corruption */
-    }
-    i = 0;
-  }
-
-  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
-  assert( pPKey2->pKeyInfo->nField+pPKey2->pKeyInfo->nXField>=pPKey2->nField 
-       || CORRUPT_DB );
-  assert( pPKey2->pKeyInfo->aSortOrder!=0 );
-  assert( pPKey2->pKeyInfo->nField>0 );
-  assert( idx1<=szHdr1 || CORRUPT_DB );
-  do{
-    u32 serial_type;
-
-    /* RHS is an integer */
-    if( pRhs->flags & MEM_Int ){
-      serial_type = aKey1[idx1];
-      testcase( serial_type==12 );
-      if( serial_type>=10 ){
-        rc = +1;
-      }else if( serial_type==0 ){
-        rc = -1;
-      }else if( serial_type==7 ){
-        sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
-        rc = -sqlite3IntFloatCompare(pRhs->u.i, mem1.u.r);
-      }else{
-        i64 lhs = vdbeRecordDecodeInt(serial_type, &aKey1[d1]);
-        i64 rhs = pRhs->u.i;
-        if( lhs<rhs ){
-          rc = -1;
-        }else if( lhs>rhs ){
-          rc = +1;
-        }
-      }
-    }
-
-    /* RHS is real */
-    else if( pRhs->flags & MEM_Real ){
-      serial_type = aKey1[idx1];
-      if( serial_type>=10 ){
-        /* Serial types 12 or greater are strings and blobs (greater than
-        ** numbers). Types 10 and 11 are currently "reserved for future 
-        ** use", so it doesn't really matter what the results of comparing
-        ** them to numberic values are.  */
-        rc = +1;
-      }else if( serial_type==0 ){
-        rc = -1;
-      }else{
-        sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
-        if( serial_type==7 ){
-          if( mem1.u.r<pRhs->u.r ){
-            rc = -1;
-          }else if( mem1.u.r>pRhs->u.r ){
-            rc = +1;
-          }
-        }else{
-          rc = sqlite3IntFloatCompare(mem1.u.i, pRhs->u.r);
-        }
-      }
-    }
-
-    /* RHS is a string */
-    else if( pRhs->flags & MEM_Str ){
-      getVarint32(&aKey1[idx1], serial_type);
-      testcase( serial_type==12 );
-      if( serial_type<12 ){
-        rc = -1;
-      }else if( !(serial_type & 0x01) ){
-        rc = +1;
-      }else{
-        mem1.n = (serial_type - 12) / 2;
-        testcase( (d1+mem1.n)==(unsigned)nKey1 );
-        testcase( (d1+mem1.n+1)==(unsigned)nKey1 );
-        if( (d1+mem1.n) > (unsigned)nKey1 ){
-          pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
-          return 0;                /* Corruption */
-        }else if( pKeyInfo->aColl[i] ){
-          mem1.enc = pKeyInfo->enc;
-          mem1.db = pKeyInfo->db;
-          mem1.flags = MEM_Str;
-          mem1.z = (char*)&aKey1[d1];
-          rc = vdbeCompareMemString(
-              &mem1, pRhs, pKeyInfo->aColl[i], &pPKey2->errCode
-          );
-        }else{
-          int nCmp = MIN(mem1.n, pRhs->n);
-          rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
-          if( rc==0 ) rc = mem1.n - pRhs->n; 
-        }
-      }
-    }
-
-    /* RHS is a blob */
-    else if( pRhs->flags & MEM_Blob ){
-      getVarint32(&aKey1[idx1], serial_type);
-      testcase( serial_type==12 );
-      if( serial_type<12 || (serial_type & 0x01) ){
-        rc = -1;
-      }else{
-        int nStr = (serial_type - 12) / 2;
-        testcase( (d1+nStr)==(unsigned)nKey1 );
-        testcase( (d1+nStr+1)==(unsigned)nKey1 );
-        if( (d1+nStr) > (unsigned)nKey1 ){
-          pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
-          return 0;                /* Corruption */
-        }else{
-          int nCmp = MIN(nStr, pRhs->n);
-          rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
-          if( rc==0 ) rc = nStr - pRhs->n;
-        }
-      }
-    }
-
-    /* RHS is null */
-    else{
-      serial_type = aKey1[idx1];
-      rc = (serial_type!=0);
-    }
-
-    if( rc!=0 ){
-      if( pKeyInfo->aSortOrder[i] ){
-        rc = -rc;
-      }
-      assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, rc) );
-      assert( mem1.szMalloc==0 );  /* See comment below */
-      return rc;
-    }
-
-    i++;
-    pRhs++;
-    d1 += sqlite3VdbeSerialTypeLen(serial_type);
-    idx1 += sqlite3VarintLen(serial_type);
-  }while( idx1<(unsigned)szHdr1 && i<pPKey2->nField && d1<=(unsigned)nKey1 );
-
-  /* No memory allocation is ever used on mem1.  Prove this using
-  ** the following assert().  If the assert() fails, it indicates a
-  ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).  */
-  assert( mem1.szMalloc==0 );
-
-  /* rc==0 here means that one or both of the keys ran out of fields and
-  ** all the fields up to that point were equal. Return the default_rc
-  ** value.  */
-  assert( CORRUPT_DB 
-       || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc) 
-       || pKeyInfo->db->mallocFailed
-  );
-  pPKey2->eqSeen = 1;
-  return pPKey2->default_rc;
-}
-int sqlite3VdbeRecordCompare(
-  int nKey1, const void *pKey1,   /* Left key */
-  UnpackedRecord *pPKey2          /* Right key */
-){
-  return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);
-}
-
-
-/*
-** This function is an optimized version of sqlite3VdbeRecordCompare() 
-** that (a) the first field of pPKey2 is an integer, and (b) the 
-** size-of-header varint at the start of (pKey1/nKey1) fits in a single
-** byte (i.e. is less than 128).
-**
-** To avoid concerns about buffer overreads, this routine is only used
-** on schemas where the maximum valid header size is 63 bytes or less.
-*/
-static int vdbeRecordCompareInt(
-  int nKey1, const void *pKey1, /* Left key */
-  UnpackedRecord *pPKey2        /* Right key */
-){
-  const u8 *aKey = &((const u8*)pKey1)[*(const u8*)pKey1 & 0x3F];
-  int serial_type = ((const u8*)pKey1)[1];
-  int res;
-  u32 y;
-  u64 x;
-  i64 v = pPKey2->aMem[0].u.i;
-  i64 lhs;
-
-  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
-  assert( (*(u8*)pKey1)<=0x3F || CORRUPT_DB );
-  switch( serial_type ){
-    case 1: { /* 1-byte signed integer */
-      lhs = ONE_BYTE_INT(aKey);
-      testcase( lhs<0 );
-      break;
-    }
-    case 2: { /* 2-byte signed integer */
-      lhs = TWO_BYTE_INT(aKey);
-      testcase( lhs<0 );
-      break;
-    }
-    case 3: { /* 3-byte signed integer */
-      lhs = THREE_BYTE_INT(aKey);
-      testcase( lhs<0 );
-      break;
-    }
-    case 4: { /* 4-byte signed integer */
-      y = FOUR_BYTE_UINT(aKey);
-      lhs = (i64)*(int*)&y;
-      testcase( lhs<0 );
-      break;
-    }
-    case 5: { /* 6-byte signed integer */
-      lhs = FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
-      testcase( lhs<0 );
-      break;
-    }
-    case 6: { /* 8-byte signed integer */
-      x = FOUR_BYTE_UINT(aKey);
-      x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
-      lhs = *(i64*)&x;
-      testcase( lhs<0 );
-      break;
-    }
-    case 8: 
-      lhs = 0;
-      break;
-    case 9:
-      lhs = 1;
-      break;
-
-    /* This case could be removed without changing the results of running
-    ** this code. Including it causes gcc to generate a faster switch 
-    ** statement (since the range of switch targets now starts at zero and
-    ** is contiguous) but does not cause any duplicate code to be generated
-    ** (as gcc is clever enough to combine the two like cases). Other 
-    ** compilers might be similar.  */ 
-    case 0: case 7:
-      return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
-
-    default:
-      return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
-  }
-
-  if( v>lhs ){
-    res = pPKey2->r1;
-  }else if( v<lhs ){
-    res = pPKey2->r2;
-  }else if( pPKey2->nField>1 ){
-    /* The first fields of the two keys are equal. Compare the trailing 
-    ** fields.  */
-    res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
-  }else{
-    /* The first fields of the two keys are equal and there are no trailing
-    ** fields. Return pPKey2->default_rc in this case. */
-    res = pPKey2->default_rc;
-    pPKey2->eqSeen = 1;
-  }
-
-  assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res) );
-  return res;
-}
-
-/*
-** This function is an optimized version of sqlite3VdbeRecordCompare() 
-** that (a) the first field of pPKey2 is a string, that (b) the first field
-** uses the collation sequence BINARY and (c) that the size-of-header varint 
-** at the start of (pKey1/nKey1) fits in a single byte.
-*/
-static int vdbeRecordCompareString(
-  int nKey1, const void *pKey1, /* Left key */
-  UnpackedRecord *pPKey2        /* Right key */
-){
-  const u8 *aKey1 = (const u8*)pKey1;
-  int serial_type;
-  int res;
-
-  assert( pPKey2->aMem[0].flags & MEM_Str );
-  vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
-  getVarint32(&aKey1[1], serial_type);
-  if( serial_type<12 ){
-    res = pPKey2->r1;      /* (pKey1/nKey1) is a number or a null */
-  }else if( !(serial_type & 0x01) ){ 
-    res = pPKey2->r2;      /* (pKey1/nKey1) is a blob */
-  }else{
-    int nCmp;
-    int nStr;
-    int szHdr = aKey1[0];
-
-    nStr = (serial_type-12) / 2;
-    if( (szHdr + nStr) > nKey1 ){
-      pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
-      return 0;    /* Corruption */
-    }
-    nCmp = MIN( pPKey2->aMem[0].n, nStr );
-    res = memcmp(&aKey1[szHdr], pPKey2->aMem[0].z, nCmp);
-
-    if( res==0 ){
-      res = nStr - pPKey2->aMem[0].n;
-      if( res==0 ){
-        if( pPKey2->nField>1 ){
-          res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
-        }else{
-          res = pPKey2->default_rc;
-          pPKey2->eqSeen = 1;
-        }
-      }else if( res>0 ){
-        res = pPKey2->r2;
-      }else{
-        res = pPKey2->r1;
-      }
-    }else if( res>0 ){
-      res = pPKey2->r2;
-    }else{
-      res = pPKey2->r1;
-    }
-  }
-
-  assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res)
-       || CORRUPT_DB
-       || pPKey2->pKeyInfo->db->mallocFailed
-  );
-  return res;
-}
-
-/*
-** Return a pointer to an sqlite3VdbeRecordCompare() compatible function
-** suitable for comparing serialized records to the unpacked record passed
-** as the only argument.
-*/
-RecordCompare sqlite3VdbeFindCompare(UnpackedRecord *p){
-  /* varintRecordCompareInt() and varintRecordCompareString() both assume
-  ** that the size-of-header varint that occurs at the start of each record
-  ** fits in a single byte (i.e. is 127 or less). varintRecordCompareInt()
-  ** also assumes that it is safe to overread a buffer by at least the 
-  ** maximum possible legal header size plus 8 bytes. Because there is
-  ** guaranteed to be at least 74 (but not 136) bytes of padding following each
-  ** buffer passed to varintRecordCompareInt() this makes it convenient to
-  ** limit the size of the header to 64 bytes in cases where the first field
-  ** is an integer.
-  **
-  ** The easiest way to enforce this limit is to consider only records with
-  ** 13 fields or less. If the first field is an integer, the maximum legal
-  ** header size is (12*5 + 1 + 1) bytes.  */
-  if( (p->pKeyInfo->nField + p->pKeyInfo->nXField)<=13 ){
-    int flags = p->aMem[0].flags;
-    if( p->pKeyInfo->aSortOrder[0] ){
-      p->r1 = 1;
-      p->r2 = -1;
-    }else{
-      p->r1 = -1;
-      p->r2 = 1;
-    }
-    if( (flags & MEM_Int) ){
-      return vdbeRecordCompareInt;
-    }
-    testcase( flags & MEM_Real );
-    testcase( flags & MEM_Null );
-    testcase( flags & MEM_Blob );
-    if( (flags & (MEM_Real|MEM_Null|MEM_Blob))==0 && p->pKeyInfo->aColl[0]==0 ){
-      assert( flags & MEM_Str );
-      return vdbeRecordCompareString;
-    }
-  }
-
-  return sqlite3VdbeRecordCompare;
-}
-
-/*
-** pCur points at an index entry created using the OP_MakeRecord opcode.
-** Read the rowid (the last field in the record) and store it in *rowid.
-** Return SQLITE_OK if everything works, or an error code otherwise.
-**
-** pCur might be pointing to text obtained from a corrupt database file.
-** So the content cannot be trusted.  Do appropriate checks on the content.
-*/
-int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
-  i64 nCellKey = 0;
-  int rc;
-  u32 szHdr;        /* Size of the header */
-  u32 typeRowid;    /* Serial type of the rowid */
-  u32 lenRowid;     /* Size of the rowid */
-  Mem m, v;
-
-  /* Get the size of the index entry.  Only indices entries of less
-  ** than 2GiB are support - anything large must be database corruption.
-  ** Any corruption is detected in sqlite3BtreeParseCellPtr(), though, so
-  ** this code can safely assume that nCellKey is 32-bits  
-  */
-  assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );     /* pCur is always valid so KeySize cannot fail */
-  assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );
-
-  /* Read in the complete content of the index entry */
-  sqlite3VdbeMemInit(&m, db, 0);
-  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
-  if( rc ){
-    return rc;
-  }
-
-  /* The index entry must begin with a header size */
-  (void)getVarint32((u8*)m.z, szHdr);
-  testcase( szHdr==3 );
-  testcase( szHdr==m.n );
-  if( unlikely(szHdr<3 || (int)szHdr>m.n) ){
-    goto idx_rowid_corruption;
-  }
-
-  /* The last field of the index should be an integer - the ROWID.
-  ** Verify that the last entry really is an integer. */
-  (void)getVarint32((u8*)&m.z[szHdr-1], typeRowid);
-  testcase( typeRowid==1 );
-  testcase( typeRowid==2 );
-  testcase( typeRowid==3 );
-  testcase( typeRowid==4 );
-  testcase( typeRowid==5 );
-  testcase( typeRowid==6 );
-  testcase( typeRowid==8 );
-  testcase( typeRowid==9 );
-  if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){
-    goto idx_rowid_corruption;
-  }
-  lenRowid = sqlite3SmallTypeSizes[typeRowid];
-  testcase( (u32)m.n==szHdr+lenRowid );
-  if( unlikely((u32)m.n<szHdr+lenRowid) ){
-    goto idx_rowid_corruption;
-  }
-
-  /* Fetch the integer off the end of the index record */
-  sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
-  *rowid = v.u.i;
-  sqlite3VdbeMemRelease(&m);
-  return SQLITE_OK;
-
-  /* Jump here if database corruption is detected after m has been
-  ** allocated.  Free the m object and return SQLITE_CORRUPT. */
-idx_rowid_corruption:
-  testcase( m.szMalloc!=0 );
-  sqlite3VdbeMemRelease(&m);
-  return SQLITE_CORRUPT_BKPT;
-}
-
-/*
-** Compare the key of the index entry that cursor pC is pointing to against
-** the key string in pUnpacked.  Write into *pRes a number
-** that is negative, zero, or positive if pC is less than, equal to,
-** or greater than pUnpacked.  Return SQLITE_OK on success.
-**
-** pUnpacked is either created without a rowid or is truncated so that it
-** omits the rowid at the end.  The rowid at the end of the index entry
-** is ignored as well.  Hence, this routine only compares the prefixes 
-** of the keys prior to the final rowid, not the entire key.
-*/
-int sqlite3VdbeIdxKeyCompare(
-  sqlite3 *db,                     /* Database connection */
-  VdbeCursor *pC,                  /* The cursor to compare against */
-  UnpackedRecord *pUnpacked,       /* Unpacked version of key */
-  int *res                         /* Write the comparison result here */
-){
-  i64 nCellKey = 0;
-  int rc;
-  BtCursor *pCur;
-  Mem m;
-
-  assert( pC->eCurType==CURTYPE_BTREE );
-  pCur = pC->uc.pCursor;
-  assert( sqlite3BtreeCursorIsValid(pCur) );
-  VVA_ONLY(rc =) sqlite3BtreeKeySize(pCur, &nCellKey);
-  assert( rc==SQLITE_OK );    /* pCur is always valid so KeySize cannot fail */
-  /* nCellKey will always be between 0 and 0xffffffff because of the way
-  ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
-  if( nCellKey<=0 || nCellKey>0x7fffffff ){
-    *res = 0;
-    return SQLITE_CORRUPT_BKPT;
-  }
-  sqlite3VdbeMemInit(&m, db, 0);
-  rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, 1, &m);
-  if( rc ){
-    return rc;
-  }
-  *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
-  sqlite3VdbeMemRelease(&m);
-  return SQLITE_OK;
-}
-
-/*
-** This routine sets the value to be returned by subsequent calls to
-** sqlite3_changes() on the database handle 'db'. 
-*/
-void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){
-  assert( sqlite3_mutex_held(db->mutex) );
-  db->nChange = nChange;
-  db->nTotalChange += nChange;
-}
-
-/*
-** Set a flag in the vdbe to update the change counter when it is finalised
-** or reset.
-*/
-void sqlite3VdbeCountChanges(Vdbe *v){
-  v->changeCntOn = 1;
-}
-
-/*
-** Mark every prepared statement associated with a database connection
-** as expired.
-**
-** An expired statement means that recompilation of the statement is
-** recommend.  Statements expire when things happen that make their
-** programs obsolete.  Removing user-defined functions or collating
-** sequences, or changing an authorization function are the types of
-** things that make prepared statements obsolete.
-*/
-void sqlite3ExpirePreparedStatements(sqlite3 *db){
-  Vdbe *p;
-  for(p = db->pVdbe; p; p=p->pNext){
-    p->expired = 1;
-  }
-}
-
-/*
-** Return the database associated with the Vdbe.
-*/
-sqlite3 *sqlite3VdbeDb(Vdbe *v){
-  return v->db;
-}
-
-/*
-** Return a pointer to an sqlite3_value structure containing the value bound
-** parameter iVar of VM v. Except, if the value is an SQL NULL, return 
-** 0 instead. Unless it is NULL, apply affinity aff (one of the SQLITE_AFF_*
-** constants) to the value before returning it.
-**
-** The returned value must be freed by the caller using sqlite3ValueFree().
-*/
-sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff){
-  assert( iVar>0 );
-  if( v ){
-    Mem *pMem = &v->aVar[iVar-1];
-    if( 0==(pMem->flags & MEM_Null) ){
-      sqlite3_value *pRet = sqlite3ValueNew(v->db);
-      if( pRet ){
-        sqlite3VdbeMemCopy((Mem *)pRet, pMem);
-        sqlite3ValueApplyAffinity(pRet, aff, SQLITE_UTF8);
-      }
-      return pRet;
-    }
-  }
-  return 0;
-}
-
-/*
-** Configure SQL variable iVar so that binding a new value to it signals
-** to sqlite3_reoptimize() that re-preparing the statement may result
-** in a better query plan.
-*/
-void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
-  assert( iVar>0 );
-  if( iVar>32 ){
-    v->expmask = 0xffffffff;
-  }else{
-    v->expmask |= ((u32)1 << (iVar-1));
-  }
-}
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-/*
-** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
-** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
-** in memory obtained from sqlite3DbMalloc).
-*/
-void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
-  sqlite3 *db = p->db;
-  sqlite3DbFree(db, p->zErrMsg);
-  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-  sqlite3_free(pVtab->zErrMsg);
-  pVtab->zErrMsg = 0;
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */