**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.520 2006/01/09 16:12:05 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
  break;
}

/* Opcode: IsUnique P1 P2 *
**
** The top of the stack is an integer record number.  Call this
** record number R.  The next on the stack is an index key created
** using MakeIdxKey.  Call it K.  This instruction pops R from the
** stack but it leaves K unchanged.
**
** P1 is an index.  So it has no data and its key consists of a
** record generated by OP_MakeRecord where the last field is the 
** rowid of the entry that the index refers to.
** 
** This instruction asks if there is an entry in P1 where the
................................................................................
  pC->rowidIsValid = 0;
  break;
}

/* Opcode: IdxInsert P1 * *
**
** The top of the stack holds a SQL index key made using the
** MakeIdxKey instruction.  This opcode writes that key into the
** index P1.  Data for the entry is nil.
**
** This instruction only works for indices.  The equivalent instruction
** for tables is OP_Insert.
*/
case OP_IdxInsert: {        /* no-push */
  int i = pOp->p1;
................................................................................
  Release(pTos);
  pTos--;
  break;
}

/* Opcode: IdxDelete P1 * *
**
** The top of the stack is an index key built using the MakeIdxKey opcode.
** This opcode removes that entry from the index.
*/
case OP_IdxDelete: {        /* no-push */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
................................................................................

/* Opcode: IdxRowid P1 * *
**
** Push onto the stack an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeIdxKey.
*/
case OP_IdxRowid: {
  int i = pOp->p1;
  BtCursor *pCrsr;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
................................................................................
  pTos--;
  break;
}

/* Opcode: IdxIsNull P1 P2 *
**
** The top of the stack contains an index entry such as might be generated
** by the MakeIdxKey opcode.  This routine looks at the first P1 fields of
** that key.  If any of the first P1 fields are NULL, then a jump is made
** to address P2.  Otherwise we fall straight through.
**
** The index entry is always popped from the stack.
*/
case OP_IdxIsNull: {        /* no-push */
  int i = pOp->p1;

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.521 2006/01/10 18:44:08 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
  break;
}

/* Opcode: IsUnique P1 P2 *
**
** The top of the stack is an integer record number.  Call this
** record number R.  The next on the stack is an index key created
** using MakeIdxRec.  Call it K.  This instruction pops R from the
** stack but it leaves K unchanged.
**
** P1 is an index.  So it has no data and its key consists of a
** record generated by OP_MakeRecord where the last field is the 
** rowid of the entry that the index refers to.
** 
** This instruction asks if there is an entry in P1 where the
................................................................................
  pC->rowidIsValid = 0;
  break;
}

/* Opcode: IdxInsert P1 * *
**
** The top of the stack holds a SQL index key made using the
** MakeIdxRec instruction.  This opcode writes that key into the
** index P1.  Data for the entry is nil.
**
** This instruction only works for indices.  The equivalent instruction
** for tables is OP_Insert.
*/
case OP_IdxInsert: {        /* no-push */
  int i = pOp->p1;
................................................................................
  Release(pTos);
  pTos--;
  break;
}

/* Opcode: IdxDelete P1 * *
**
** The top of the stack is an index key built using the MakeIdxRec opcode.
** This opcode removes that entry from the index.
*/
case OP_IdxDelete: {        /* no-push */
  int i = pOp->p1;
  Cursor *pC;
  BtCursor *pCrsr;
  assert( pTos>=p->aStack );
................................................................................

/* Opcode: IdxRowid P1 * *
**
** Push onto the stack an integer which is the last entry in the record at
** the end of the index key pointed to by cursor P1.  This integer should be
** the rowid of the table entry to which this index entry points.
**
** See also: Rowid, MakeIdxRec.
*/
case OP_IdxRowid: {
  int i = pOp->p1;
  BtCursor *pCrsr;
  Cursor *pC;

  assert( i>=0 && i<p->nCursor );
................................................................................
  pTos--;
  break;
}

/* Opcode: IdxIsNull P1 P2 *
**
** The top of the stack contains an index entry such as might be generated
** by the MakeIdxRec opcode.  This routine looks at the first P1 fields of
** that key.  If any of the first P1 fields are NULL, then a jump is made
** to address P2.  Otherwise we fall straight through.
**
** The index entry is always popped from the stack.
*/
case OP_IdxIsNull: {        /* no-push */
  int i = pOp->p1;