SQLite

**
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** 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 1.767 2008/07/29 10:18:57 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

  pOp->opcode = OP_String;
  pOp->p1 = strlen(pOp->p4.z);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pOut) ) goto no_mem;
    pOut->zMalloc = 0;
    pOut->flags |= MEM_Static;
    pOut->flags &= ~MEM_Dyn;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3DbFree(db, pOp->p4.z);
    }
    pOp->p4type = P4_DYNAMIC;

*************************************************************************
** This is the header file for information that is private to the
** VDBE.  This information used to all be at the top of the single
** source code file "vdbe.c".  When that file became too big (over
** 6000 lines long) it was split up into several smaller files and
** this header information was factored out.
**
** $Id: vdbeInt.h,v 1.151 2008/07/28 19:34:54 drh Exp $
*/
#ifndef _VDBEINT_H_
#define _VDBEINT_H_

/*
** intToKey() and keyToInt() used to transform the rowid.  But with
** the latest versions of the design they are no-ops.

int sqlite3VdbeMemNulTerminate(Mem*);
int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
void sqlite3VdbeMemSetInt64(Mem*, i64);
void sqlite3VdbeMemSetDouble(Mem*, double);
void sqlite3VdbeMemSetNull(Mem*);
void sqlite3VdbeMemSetZeroBlob(Mem*,int);
int sqlite3VdbeMemMakeWriteable(Mem*);
int sqlite3VdbeMemDynamicify(Mem*);
int sqlite3VdbeMemStringify(Mem*, int);
i64 sqlite3VdbeIntValue(Mem*);
int sqlite3VdbeMemIntegerify(Mem*);
double sqlite3VdbeRealValue(Mem*);
void sqlite3VdbeIntegerAffinity(Mem*);
int sqlite3VdbeMemRealify(Mem*);
int sqlite3VdbeMemNumerify(Mem*);

*************************************************************************
**
** This file contains code use to manipulate "Mem" structure.  A "Mem"
** stores a single value in the VDBE.  Mem is an opaque structure visible
** only within the VDBE.  Interface routines refer to a Mem using the
** name sqlite_value
**
** $Id: vdbemem.c,v 1.119 2008/07/28 19:34:54 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** Call sqlite3VdbeMemExpandBlob() on the supplied value (type Mem*)

  pMem->z = pMem->zMalloc;
  pMem->flags &= ~(MEM_Ephem|MEM_Static);
  pMem->xDel = 0;
  return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
}

/*
** Make the given Mem object MEM_Dyn.



**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemDynamicify(Mem *pMem){
  int f;
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  expandBlob(pMem);
  f = pMem->flags;
  if( (f&(MEM_Str|MEM_Blob)) && pMem->z!=pMem->zMalloc ){
    if( sqlite3VdbeMemGrow(pMem, pMem->n + 2, 1) ){
      return SQLITE_NOMEM;

    pMem->flags &= ~(MEM_Zero|MEM_Term);
  }
  return SQLITE_OK;
}
#endif


/*
** Make the given Mem object either MEM_Short or MEM_Dyn so that bytes
** of the Mem.z[] array can be modified.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
int sqlite3VdbeMemMakeWriteable(Mem *pMem){
  return sqlite3VdbeMemDynamicify(pMem);
}

/*
** Make sure the given Mem is \u0000 terminated.
*/
int sqlite3VdbeMemNulTerminate(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  if( (pMem->flags & MEM_Term)!=0 || (pMem->flags & MEM_Str)==0 ){
    return SQLITE_OK;   /* Nothing to do */