root/ext/sqlite/libsqlite/src/vdbeaux.c

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DEFINITIONS

This source file includes following definitions.
  1. sqliteVdbeCreate
  2. sqliteVdbeTrace
  3. sqliteVdbeAddOp
  4. sqliteVdbeOp3
  5. sqliteVdbeCode
  6. sqliteVdbeMakeLabel
  7. sqliteVdbeResolveLabel
  8. sqliteVdbeCurrentAddr
  9. sqliteVdbeAddOpList
  10. sqliteVdbeChangeP1
  11. sqliteVdbeChangeP2
  12. sqliteVdbeChangeP3
  13. sqliteVdbeDequoteP3
  14. sqliteVdbeCompressSpace
  15. sqliteVdbeFindOp
  16. sqliteVdbeGetOp
  17. sqlite_set_result_string
  18. sqlite_set_result_int
  19. sqlite_set_result_double
  20. sqlite_set_result_error
  21. sqlite_user_data
  22. sqlite_aggregate_context
  23. sqlite_aggregate_count
  24. sqliteVdbePrintOp
  25. sqliteVdbeList
  26. sqliteVdbeMakeReady
  27. sqliteVdbeSorterReset
  28. sqliteVdbeAggReset
  29. sqliteVdbeKeylistFree
  30. sqliteVdbeCleanupCursor
  31. closeAllCursors
  32. Cleanup
  33. sqliteVdbeReset
  34. sqliteVdbeFinalize
  35. sqlite_bind
  36. sqliteVdbeDelete
  37. sqliteVdbeByteSwap
  38. sqliteVdbeCursorMoveto

/*
** 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 "sqlite_vm" as it is known to the outside world.)  Prior
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"


/*
** When debugging the code generator in a symbolic debugger, one can
** set the sqlite_vdbe_addop_trace to 1 and all opcodes will be printed
** as they are added to the instruction stream.
*/
#ifndef NDEBUG
int sqlite_vdbe_addop_trace = 0;
#endif


/*
** Create a new virtual database engine.
*/
Vdbe *sqliteVdbeCreate(sqlite *db){
  Vdbe *p;
  p = sqliteMalloc( 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;
  return p;
}

/*
** Turn tracing on or off
*/
void sqliteVdbeTrace(Vdbe *p, FILE *trace){
  p->trace = trace;
}

/*
** 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          First two of the three possible operands.
**
** Use the sqliteVdbeResolveLabel() function to fix an address and
** the sqliteVdbeChangeP3() function to change the value of the P3
** operand.
*/
int sqliteVdbeAddOp(Vdbe *p, int op, int p1, int p2){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  p->nOp++;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( i>=p->nOpAlloc ){
    int oldSize = p->nOpAlloc;
    Op *aNew;
    p->nOpAlloc = p->nOpAlloc*2 + 100;
    aNew = sqliteRealloc(p->aOp, p->nOpAlloc*sizeof(Op));
    if( aNew==0 ){
      p->nOpAlloc = oldSize;
      return 0;
    }
    p->aOp = aNew;
    memset(&p->aOp[oldSize], 0, (p->nOpAlloc-oldSize)*sizeof(Op));
  }
  pOp = &p->aOp[i];
  pOp->opcode = op;
  pOp->p1 = p1;
  if( p2<0 && (-1-p2)<p->nLabel && p->aLabel[-1-p2]>=0 ){
    p2 = p->aLabel[-1-p2];
  }
  pOp->p2 = p2;
  pOp->p3 = 0;
  pOp->p3type = P3_NOTUSED;
#ifndef NDEBUG
  if( sqlite_vdbe_addop_trace ) sqliteVdbePrintOp(0, i, &p->aOp[i]);
#endif
  return i;
}

/*
** Add an opcode that includes the p3 value.
*/
int sqliteVdbeOp3(Vdbe *p, int op, int p1, int p2, const char *zP3, int p3type){
  int addr = sqliteVdbeAddOp(p, op, p1, p2);
  sqliteVdbeChangeP3(p, addr, zP3, p3type);
  return addr;
}

/*
** Add multiple opcodes.  The list is terminated by an opcode of 0.
*/
int sqliteVdbeCode(Vdbe *p, ...){
  int addr;
  va_list ap;
  int opcode, p1, p2;
  va_start(ap, p);
  addr = p->nOp;
  while( (opcode = va_arg(ap,int))!=0 ){
    p1 = va_arg(ap,int);
    p2 = va_arg(ap,int);
    sqliteVdbeAddOp(p, opcode, p1, p2);
  }
  va_end(ap);
  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.
*/
int sqliteVdbeMakeLabel(Vdbe *p){
  int i;
  i = p->nLabel++;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( i>=p->nLabelAlloc ){
    int *aNew;
    p->nLabelAlloc = p->nLabelAlloc*2 + 10;
    aNew = sqliteRealloc( p->aLabel, p->nLabelAlloc*sizeof(p->aLabel[0]));
    if( aNew==0 ){
      sqliteFree(p->aLabel);
    }
    p->aLabel = aNew;
  }
  if( p->aLabel==0 ){
    p->nLabel = 0;
    p->nLabelAlloc = 0;
    return 0;
  }
  p->aLabel[i] = -1;
  return -1-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 sqliteVdbeMakeLabel().
*/
void sqliteVdbeResolveLabel(Vdbe *p, int x){
  int j;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( x<0 && (-x)<=p->nLabel && p->aOp ){
    if( p->aLabel[-1-x]==p->nOp ) return;
    assert( p->aLabel[-1-x]<0 );
    p->aLabel[-1-x] = p->nOp;
    for(j=0; j<p->nOp; j++){
      if( p->aOp[j].p2==x ) p->aOp[j].p2 = p->nOp;
    }
  }
}

/*
** Return the address of the next instruction to be inserted.
*/
int sqliteVdbeCurrentAddr(Vdbe *p){
  assert( p->magic==VDBE_MAGIC_INIT );
  return p->nOp;
}

/*
** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.
*/
int sqliteVdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
  int addr;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp >= p->nOpAlloc ){
    int oldSize = p->nOpAlloc;
    Op *aNew;
    p->nOpAlloc = p->nOpAlloc*2 + nOp + 10;
    aNew = sqliteRealloc(p->aOp, p->nOpAlloc*sizeof(Op));
    if( aNew==0 ){
      p->nOpAlloc = oldSize;
      return 0;
    }
    p->aOp = aNew;
    memset(&p->aOp[oldSize], 0, (p->nOpAlloc-oldSize)*sizeof(Op));
  }
  addr = p->nOp;
  if( nOp>0 ){
    int i;
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){
      int p2 = pIn->p2;
      VdbeOp *pOut = &p->aOp[i+addr];
      pOut->opcode = pIn->opcode;
      pOut->p1 = pIn->p1;
      pOut->p2 = p2<0 ? addr + ADDR(p2) : p2;
      pOut->p3 = pIn->p3;
      pOut->p3type = pIn->p3 ? P3_STATIC : P3_NOTUSED;
#ifndef NDEBUG
      if( sqlite_vdbe_addop_trace ){
        sqliteVdbePrintOp(0, i+addr, &p->aOp[i+addr]);
      }
#endif
    }
    p->nOp += nOp;
  }
  return addr;
}

/*
** Change the value of the P1 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqliteVdbeAddOpList but we want to make a
** few minor changes to the program.
*/
void sqliteVdbeChangeP1(Vdbe *p, int addr, int val){
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p && addr>=0 && p->nOp>addr && p->aOp ){
    p->aOp[addr].p1 = val;
  }
}

/*
** Change the value of the P2 operand for a specific instruction.
** This routine is useful for setting a jump destination.
*/
void sqliteVdbeChangeP2(Vdbe *p, int addr, int val){
  assert( val>=0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p && addr>=0 && p->nOp>addr && p->aOp ){
    p->aOp[addr].p2 = val;
  }
}

/*
** Change the value of the P3 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqliteVdbeAddOpList but we want to make a
** few minor changes to the program.
**
** If n>=0 then the P3 operand is dynamic, meaning that a copy of
** the string is made into memory obtained from sqliteMalloc().
** A value of n==0 means copy bytes of zP3 up to and including the
** first null byte.  If n>0 then copy n+1 bytes of zP3.
**
** If n==P3_STATIC  it means that zP3 is a pointer to a constant static
** string and we can just copy the pointer.  n==P3_POINTER means zP3 is
** a pointer to some object other than a string.
**
** If addr<0 then change P3 on the most recently inserted instruction.
*/
void sqliteVdbeChangeP3(Vdbe *p, int addr, const char *zP3, int n){
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p==0 || p->aOp==0 ) return;
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }
  pOp = &p->aOp[addr];
  if( pOp->p3 && pOp->p3type==P3_DYNAMIC ){
    sqliteFree(pOp->p3);
    pOp->p3 = 0;
  }
  if( zP3==0 ){
    pOp->p3 = 0;
    pOp->p3type = P3_NOTUSED;
  }else if( n<0 ){
    pOp->p3 = (char*)zP3;
    pOp->p3type = n;
  }else{
    sqliteSetNString(&pOp->p3, zP3, n, 0);
    pOp->p3type = P3_DYNAMIC;
  }
}

/*
** If the P3 operand to the specified instruction appears
** to be a quoted string token, then this procedure removes 
** the quotes.
**
** The quoting operator can be either a grave ascent (ASCII 0x27)
** or a double quote character (ASCII 0x22).  Two quotes in a row
** resolve to be a single actual quote character within the string.
*/
void sqliteVdbeDequoteP3(Vdbe *p, int addr){
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->aOp==0 ) return;
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }
  pOp = &p->aOp[addr];
  if( pOp->p3==0 || pOp->p3[0]==0 ) return;
  if( pOp->p3type==P3_POINTER ) return;
  if( pOp->p3type!=P3_DYNAMIC ){
    pOp->p3 = sqliteStrDup(pOp->p3);
    pOp->p3type = P3_DYNAMIC;
  }
  sqliteDequote(pOp->p3);
}

/*
** On the P3 argument of the given instruction, change all
** strings of whitespace characters into a single space and
** delete leading and trailing whitespace.
*/
void sqliteVdbeCompressSpace(Vdbe *p, int addr){
  unsigned char *z;
  int i, j;
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->aOp==0 || addr<0 || addr>=p->nOp ) return;
  pOp = &p->aOp[addr];
  if( pOp->p3type==P3_POINTER ){
    return;
  }
  if( pOp->p3type!=P3_DYNAMIC ){
    pOp->p3 = sqliteStrDup(pOp->p3);
    pOp->p3type = P3_DYNAMIC;
  }
  z = (unsigned char*)pOp->p3;
  if( z==0 ) return;
  i = j = 0;
  while( isspace(z[i]) ){ i++; }
  while( z[i] ){
    if( isspace(z[i]) ){
      z[j++] = ' ';
      while( isspace(z[++i]) ){}
    }else{
      z[j++] = z[i++];
    }
  }
  while( j>0 && isspace(z[j-1]) ){ j--; }
  z[j] = 0;
}

/*
** Search for the current program for the given opcode and P2
** value.  Return the address plus 1 if found and 0 if not found.
*/
int sqliteVdbeFindOp(Vdbe *p, int op, int p2){
  int i;
  assert( p->magic==VDBE_MAGIC_INIT );
  for(i=0; i<p->nOp; i++){
    if( p->aOp[i].opcode==op && p->aOp[i].p2==p2 ) return i+1;
  }
  return 0;
}

/*
** Return the opcode for a given address.
*/
VdbeOp *sqliteVdbeGetOp(Vdbe *p, int addr){
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( addr>=0 && addr<p->nOp );
  return &p->aOp[addr];
}

/*
** The following group or routines are employed by installable functions
** to return their results.
**
** The sqlite_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.
** A copy is made of the string before this routine returns so it is safe
** to pass in an ephemeral string.
**
** sqlite_set_result_error() works like sqlite_set_result_string() except
** that it signals a fatal error.  The string argument, if any, is the
** error message.  If the argument is NULL a generic substitute error message
** is used.
**
** The sqlite_set_result_int() and sqlite_set_result_double() set the return
** value of the user function to an integer or a double.
**
** These routines are defined here in vdbe.c because they depend on knowing
** the internals of the sqlite_func structure which is only defined in 
** this source file.
*/
char *sqlite_set_result_string(sqlite_func *p, const char *zResult, int n){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  if( zResult==0 ){
    p->s.flags = MEM_Null;
    n = 0;
    p->s.z = 0;
    p->s.n = 0;
  }else{
    if( n<0 ) n = strlen(zResult);
    if( n<NBFS-1 ){
      memcpy(p->s.zShort, zResult, n);
      p->s.zShort[n] = 0;
      p->s.flags = MEM_Str | MEM_Short;
      p->s.z = p->s.zShort;
    }else{
      p->s.z = sqliteMallocRaw( n+1 );
      if( p->s.z ){
        memcpy(p->s.z, zResult, n);
        p->s.z[n] = 0;
      }
      p->s.flags = MEM_Str | MEM_Dyn;
    }
    p->s.n = n+1;
  }
  return p->s.z;
}
void sqlite_set_result_int(sqlite_func *p, int iResult){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  p->s.i = iResult;
  p->s.flags = MEM_Int;
}
void sqlite_set_result_double(sqlite_func *p, double rResult){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  p->s.r = rResult;
  p->s.flags = MEM_Real;
}
void sqlite_set_result_error(sqlite_func *p, const char *zMsg, int n){
  assert( !p->isStep );
  sqlite_set_result_string(p, zMsg, n);
  p->isError = 1;
}

/*
** Extract the user data from a sqlite_func structure and return a
** pointer to it.
*/
void *sqlite_user_data(sqlite_func *p){
  assert( p && p->pFunc );
  return p->pFunc->pUserData;
}

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
void *sqlite_aggregate_context(sqlite_func *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  if( p->pAgg==0 ){
    if( nByte<=NBFS ){
      p->pAgg = (void*)p->s.z;
      memset(p->pAgg, 0, nByte);
    }else{
      p->pAgg = sqliteMalloc( nByte );
    }
  }
  return p->pAgg;
}

/*
** Return the number of times the Step function of a aggregate has been 
** called.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
int sqlite_aggregate_count(sqlite_func *p){
  assert( p && p->pFunc && p->pFunc->xStep );
  return p->cnt;
}

#if !defined(NDEBUG) || defined(VDBE_PROFILE)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqliteVdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP3;
  char zPtr[40];
  if( pOp->p3type==P3_POINTER ){
    sprintf(zPtr, "ptr(%#lx)", (long)pOp->p3);
    zP3 = zPtr;
  }else{
    zP3 = pOp->p3;
  }
  if( pOut==0 ) pOut = stdout;
  fprintf(pOut,"%4d %-12s %4d %4d %s\n",
      pc, sqliteOpcodeNames[pOp->opcode], pOp->p1, pOp->p2, zP3 ? zP3 : "");
  fflush(pOut);
}
#endif

/*
** Give a listing of the program in the virtual machine.
**
** The interface is the same as sqliteVdbeExec().  But instead of
** running the code, it invokes the callback once for each instruction.
** This feature is used to implement "EXPLAIN".
*/
int sqliteVdbeList(
  Vdbe *p                   /* The VDBE */
){
  sqlite *db = p->db;
  int i;
  int rc = SQLITE_OK;
  static char *azColumnNames[] = {
     "addr", "opcode", "p1",  "p2",  "p3", 
     "int",  "text",   "int", "int", "text",
     0
  };

  assert( p->popStack==0 );
  assert( p->explain );
  p->azColName = azColumnNames;
  p->azResColumn = p->zArgv;
  for(i=0; i<5; i++) p->zArgv[i] = p->aStack[i].zShort;
  i = p->pc;
  if( i>=p->nOp ){
    p->rc = SQLITE_OK;
    rc = SQLITE_DONE;
  }else if( db->flags & SQLITE_Interrupt ){
    db->flags &= ~SQLITE_Interrupt;
    if( db->magic!=SQLITE_MAGIC_BUSY ){
      p->rc = SQLITE_MISUSE;
    }else{
      p->rc = SQLITE_INTERRUPT;
    }
    rc = SQLITE_ERROR;
    sqliteSetString(&p->zErrMsg, sqlite_error_string(p->rc), (char*)0);
  }else{
    sprintf(p->zArgv[0],"%d",i);
    sprintf(p->zArgv[2],"%d", p->aOp[i].p1);
    sprintf(p->zArgv[3],"%d", p->aOp[i].p2);
    if( p->aOp[i].p3type==P3_POINTER ){
      sprintf(p->aStack[4].zShort, "ptr(%#lx)", (long)p->aOp[i].p3);
      p->zArgv[4] = p->aStack[4].zShort;
    }else{
      p->zArgv[4] = p->aOp[i].p3;
    }
    p->zArgv[1] = sqliteOpcodeNames[p->aOp[i].opcode];
    p->pc = i+1;
    p->azResColumn = p->zArgv;
    p->nResColumn = 5;
    p->rc = SQLITE_OK;
    rc = SQLITE_ROW;
  }
  return rc;
}

/*
** Prepare a virtual machine for execution.  This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqliteVdbeExec().  
*/
void sqliteVdbeMakeReady(
  Vdbe *p,                       /* The VDBE */
  int nVar,                      /* Number of '?' see in the SQL statement */
  int isExplain                  /* True if the EXPLAIN keywords is present */
){
  int n;

  assert( p!=0 );
  assert( p->magic==VDBE_MAGIC_INIT );

  /* Add a HALT instruction to the very end of the program.
  */
  if( p->nOp==0 || (p->aOp && p->aOp[p->nOp-1].opcode!=OP_Halt) ){
    sqliteVdbeAddOp(p, OP_Halt, 0, 0);
  }

  /* No instruction ever pushes more than a single element onto the
  ** stack.  And the stack never grows on successive executions of the
  ** same loop.  So the total number of instructions is an upper bound
  ** on the maximum stack depth required.
  **
  ** Allocation all the stack space we will ever need.
  */
  if( p->aStack==0 ){
    p->nVar = nVar;
    assert( nVar>=0 );
    n = isExplain ? 10 : p->nOp;
    p->aStack = sqliteMalloc(
      n*(sizeof(p->aStack[0]) + 2*sizeof(char*))     /* aStack and zArgv */
        + p->nVar*(sizeof(char*)+sizeof(int)+1)    /* azVar, anVar, abVar */
    );
    p->zArgv = (char**)&p->aStack[n];
    p->azColName = (char**)&p->zArgv[n];
    p->azVar = (char**)&p->azColName[n];
    p->anVar = (int*)&p->azVar[p->nVar];
    p->abVar = (u8*)&p->anVar[p->nVar];
  }

  sqliteHashInit(&p->agg.hash, SQLITE_HASH_BINARY, 0);
  p->agg.pSearch = 0;
#ifdef MEMORY_DEBUG
  if( sqliteOsFileExists("vdbe_trace") ){
    p->trace = stdout;
  }
#endif
  p->pTos = &p->aStack[-1];
  p->pc = 0;
  p->rc = SQLITE_OK;
  p->uniqueCnt = 0;
  p->returnDepth = 0;
  p->errorAction = OE_Abort;
  p->undoTransOnError = 0;
  p->popStack =  0;
  p->explain |= isExplain;
  p->magic = VDBE_MAGIC_RUN;
#ifdef VDBE_PROFILE
  {
    int i;
    for(i=0; i<p->nOp; i++){
      p->aOp[i].cnt = 0;
      p->aOp[i].cycles = 0;
    }
  }
#endif
}


/*
** Remove any elements that remain on the sorter for the VDBE given.
*/
void sqliteVdbeSorterReset(Vdbe *p){
  while( p->pSort ){
    Sorter *pSorter = p->pSort;
    p->pSort = pSorter->pNext;
    sqliteFree(pSorter->zKey);
    sqliteFree(pSorter->pData);
    sqliteFree(pSorter);
  }
}

/*
** Reset an Agg structure.  Delete all its contents. 
**
** For installable aggregate functions, if the step function has been
** called, make sure the finalizer function has also been called.  The
** finalizer might need to free memory that was allocated as part of its
** private context.  If the finalizer has not been called yet, call it
** now.
*/
void sqliteVdbeAggReset(Agg *pAgg){
  int i;
  HashElem *p;
  for(p = sqliteHashFirst(&pAgg->hash); p; p = sqliteHashNext(p)){
    AggElem *pElem = sqliteHashData(p);
    assert( pAgg->apFunc!=0 );
    for(i=0; i<pAgg->nMem; i++){
      Mem *pMem = &pElem->aMem[i];
      if( pAgg->apFunc[i] && (pMem->flags & MEM_AggCtx)!=0 ){
        sqlite_func ctx;
        ctx.pFunc = pAgg->apFunc[i];
        ctx.s.flags = MEM_Null;
        ctx.pAgg = pMem->z;
        ctx.cnt = pMem->i;
        ctx.isStep = 0;
        ctx.isError = 0;
        (*pAgg->apFunc[i]->xFinalize)(&ctx);
        if( pMem->z!=0 && pMem->z!=pMem->zShort ){
          sqliteFree(pMem->z);
        }
        if( ctx.s.flags & MEM_Dyn ){
          sqliteFree(ctx.s.z);
        }
      }else if( pMem->flags & MEM_Dyn ){
        sqliteFree(pMem->z);
      }
    }
    sqliteFree(pElem);
  }
  sqliteHashClear(&pAgg->hash);
  sqliteFree(pAgg->apFunc);
  pAgg->apFunc = 0;
  pAgg->pCurrent = 0;
  pAgg->pSearch = 0;
  pAgg->nMem = 0;
}

/*
** Delete a keylist
*/
void sqliteVdbeKeylistFree(Keylist *p){
  while( p ){
    Keylist *pNext = p->pNext;
    sqliteFree(p);
    p = pNext;
  }
}

/*
** Close a cursor and release all the resources that cursor happens
** to hold.
*/
void sqliteVdbeCleanupCursor(Cursor *pCx){
  if( pCx->pCursor ){
    sqliteBtreeCloseCursor(pCx->pCursor);
  }
  if( pCx->pBt ){
    sqliteBtreeClose(pCx->pBt);
  }
  sqliteFree(pCx->pData);
  memset(pCx, 0, sizeof(Cursor));
}

/*
** Close all cursors
*/
static void closeAllCursors(Vdbe *p){
  int i;
  for(i=0; i<p->nCursor; i++){
    sqliteVdbeCleanupCursor(&p->aCsr[i]);
  }
  sqliteFree(p->aCsr);
  p->aCsr = 0;
  p->nCursor = 0;
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, lists, and/or
** sorters that were left open.  It also deletes the values of
** variables in the azVariable[] array.
*/
static void Cleanup(Vdbe *p){
  int i;
  if( p->aStack ){
    Mem *pTos = p->pTos;
    while( pTos>=p->aStack ){
      if( pTos->flags & MEM_Dyn ){
        sqliteFree(pTos->z);
      }
      pTos--;
    }
    p->pTos = pTos;
  }
  closeAllCursors(p);
  if( p->aMem ){
    for(i=0; i<p->nMem; i++){
      if( p->aMem[i].flags & MEM_Dyn ){
        sqliteFree(p->aMem[i].z);
      }
    }
  }
  sqliteFree(p->aMem);
  p->aMem = 0;
  p->nMem = 0;
  if( p->pList ){
    sqliteVdbeKeylistFree(p->pList);
    p->pList = 0;
  }
  sqliteVdbeSorterReset(p);
  if( p->pFile ){
    if( p->pFile!=stdin ) fclose(p->pFile);
    p->pFile = 0;
  }
  if( p->azField ){
    sqliteFree(p->azField);
    p->azField = 0;
  }
  p->nField = 0;
  if( p->zLine ){
    sqliteFree(p->zLine);
    p->zLine = 0;
  }
  p->nLineAlloc = 0;
  sqliteVdbeAggReset(&p->agg);
  if( p->aSet ){
    for(i=0; i<p->nSet; i++){
      sqliteHashClear(&p->aSet[i].hash);
    }
  }
  sqliteFree(p->aSet);
  p->aSet = 0;
  p->nSet = 0;
  if( p->keylistStack ){
    int ii;
    for(ii = 0; ii < p->keylistStackDepth; ii++){
      sqliteVdbeKeylistFree(p->keylistStack[ii]);
    }
    sqliteFree(p->keylistStack);
    p->keylistStackDepth = 0;
    p->keylistStack = 0;
  }
  sqliteFree(p->contextStack);
  p->contextStack = 0;
  sqliteFree(p->zErrMsg);
  p->zErrMsg = 0;
}

/*
** 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.
*/
int sqliteVdbeReset(Vdbe *p, char **pzErrMsg){
  sqlite *db = p->db;
  int i;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  if( p->zErrMsg ){
    if( pzErrMsg && *pzErrMsg==0 ){
      *pzErrMsg = p->zErrMsg;
    }else{
      sqliteFree(p->zErrMsg);
    }
    p->zErrMsg = 0;
  }else if( p->rc ){
    sqliteSetString(pzErrMsg, sqlite_error_string(p->rc), (char*)0);
  }
  Cleanup(p);
  if( p->rc!=SQLITE_OK ){
    switch( p->errorAction ){
      case OE_Abort: {
        if( !p->undoTransOnError ){
          for(i=0; i<db->nDb; i++){
            if( db->aDb[i].pBt ){
              sqliteBtreeRollbackCkpt(db->aDb[i].pBt);
            }
          }
          break;
        }
        /* Fall through to ROLLBACK */
      }
      case OE_Rollback: {
        sqliteRollbackAll(db);
        db->flags &= ~SQLITE_InTrans;
        db->onError = OE_Default;
        break;
      }
      default: {
        if( p->undoTransOnError ){
          sqliteRollbackAll(db);
          db->flags &= ~SQLITE_InTrans;
          db->onError = OE_Default;
        }
        break;
      }
    }
    sqliteRollbackInternalChanges(db);
  }
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt && db->aDb[i].inTrans==2 ){
      sqliteBtreeCommitCkpt(db->aDb[i].pBt);
      db->aDb[i].inTrans = 1;
    }
  }
  assert( p->pTos<&p->aStack[p->pc] || sqlite_malloc_failed==1 );
#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");
      for(i=0; i<p->nOp; i++){
        fprintf(out, "%6d %10lld %8lld ",
           p->aOp[i].cnt,
           p->aOp[i].cycles,
           p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
        );
        sqliteVdbePrintOp(out, i, &p->aOp[i]);
      }
      fclose(out);
    }
  }
#endif
  p->magic = VDBE_MAGIC_INIT;
  return p->rc;
}

/*
** Clean up and delete a VDBE after execution.  Return an integer which is
** the result code.  Write any error message text into *pzErrMsg.
*/
int sqliteVdbeFinalize(Vdbe *p, char **pzErrMsg){
  int rc;
  sqlite *db;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  db = p->db;
  rc = sqliteVdbeReset(p, pzErrMsg);
  sqliteVdbeDelete(p);
  if( db->want_to_close && db->pVdbe==0 ){
    sqlite_close(db);
  }
  if( rc==SQLITE_SCHEMA ){
    sqliteResetInternalSchema(db, 0);
  }
  return rc;
}

/*
** Set the values of all variables.  Variable $1 in the original SQL will
** be the string azValue[0].  $2 will have the value azValue[1].  And
** so forth.  If a value is out of range (for example $3 when nValue==2)
** then its value will be NULL.
**
** This routine overrides any prior call.
*/
int sqlite_bind(sqlite_vm *pVm, int i, const char *zVal, int len, int copy){
  Vdbe *p = (Vdbe*)pVm;
  if( p->magic!=VDBE_MAGIC_RUN || p->pc!=0 ){
    return SQLITE_MISUSE;
  }
  if( i<1 || i>p->nVar ){
    return SQLITE_RANGE;
  }
  i--;
  if( p->abVar[i] ){
    sqliteFree(p->azVar[i]);
  }
  if( zVal==0 ){
    copy = 0;
    len = 0;
  }
  if( len<0 ){
    len = strlen(zVal)+1;
  }
  if( copy ){
    p->azVar[i] = sqliteMalloc( len );
    if( p->azVar[i] ) memcpy(p->azVar[i], zVal, len);
  }else{
    p->azVar[i] = (char*)zVal;
  }
  p->abVar[i] = copy;
  p->anVar[i] = len;
  return SQLITE_OK;
}


/*
** Delete an entire VDBE.
*/
void sqliteVdbeDelete(Vdbe *p){
  int i;
  if( p==0 ) return;
  Cleanup(p);
  if( p->pPrev ){
    p->pPrev->pNext = p->pNext;
  }else{
    assert( p->db->pVdbe==p );
    p->db->pVdbe = p->pNext;
  }
  if( p->pNext ){
    p->pNext->pPrev = p->pPrev;
  }
  p->pPrev = p->pNext = 0;
  if( p->nOpAlloc==0 ){
    p->aOp = 0;
    p->nOp = 0;
  }
  for(i=0; i<p->nOp; i++){
    if( p->aOp[i].p3type==P3_DYNAMIC ){
      sqliteFree(p->aOp[i].p3);
    }
  }
  for(i=0; i<p->nVar; i++){
    if( p->abVar[i] ) sqliteFree(p->azVar[i]);
  }
  sqliteFree(p->aOp);
  sqliteFree(p->aLabel);
  sqliteFree(p->aStack);
  p->magic = VDBE_MAGIC_DEAD;
  sqliteFree(p);
}

/*
** Convert an integer in between the native integer format and
** the bigEndian format used as the record number for tables.
**
** The bigEndian format (most significant byte first) is used for
** record numbers so that records will sort into the correct order
** even though memcmp() is used to compare the keys.  On machines
** whose native integer format is little endian (ex: i486) the
** order of bytes is reversed.  On native big-endian machines
** (ex: Alpha, Sparc, Motorola) the byte order is the same.
**
** This function is its own inverse.  In other words
**
**         X == byteSwap(byteSwap(X))
*/
int sqliteVdbeByteSwap(int x){
  union {
     char zBuf[sizeof(int)];
     int i;
  } ux;
  ux.zBuf[3] = x&0xff;
  ux.zBuf[2] = (x>>8)&0xff;
  ux.zBuf[1] = (x>>16)&0xff;
  ux.zBuf[0] = (x>>24)&0xff;
  return ux.i;
}

/*
** If a MoveTo operation is pending on the given cursor, then do that
** MoveTo now.  Return an error code.  If no MoveTo is pending, this
** routine does nothing and returns SQLITE_OK.
*/
int sqliteVdbeCursorMoveto(Cursor *p){
  if( p->deferredMoveto ){
    int res;
    extern int sqlite_search_count;
    sqliteBtreeMoveto(p->pCursor, (char*)&p->movetoTarget, sizeof(int), &res);
    p->lastRecno = keyToInt(p->movetoTarget);
    p->recnoIsValid = res==0;
    if( res<0 ){
      sqliteBtreeNext(p->pCursor, &res);
    }
    sqlite_search_count++;
    p->deferredMoveto = 0;
  }
  return SQLITE_OK;
}

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