SQLite

/*
** 2004 April 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.
**
*************************************************************************
** $Id: btreeInt.h,v 1.3 2007/05/16 14:23:00 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

  char *zErrMsg;    /* An error message.  NULL if no errors seen. */
  int nErr;         /* Number of messages written to zErrMsg so far */
};

/*
** Read or write a two- and four-byte big-endian integer values.
*/
#define get2byte(x) ((x)[0]<<8 | (x)[1])
#define get4byte sqlite3Get4byte
#define put2byte sqlite3Put2byte
#define put4byte sqlite3Put4byte

/*
** Internal routines that should be accessed by the btree layer only.
*/

**
** 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 1.620 2007/05/16 14:23:00 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <math.h>
#include "vdbeInt.h"

#if 0
        fprintf(stdout, "%10lld ", elapse);
        sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
#endif
    }
#endif

#if defined(SQLITE_TEST) && !defined(NDEBUG)
    /* Keep track of the size of the largest BLOB or STR that has appeared
    ** on the top of the VDBE stack.
    */
    if( pTos>=p->aStack && (pTos->flags & (MEM_Blob|MEM_Str))!=0
         && pTos->n>sqlite3_max_blobsize ){
      sqlite3_max_blobsize = pTos->n;
    }

#define MEM_Dyn       0x0040   /* Need to call sqliteFree() on Mem.z */
#define MEM_Static    0x0080   /* Mem.z points to a static string */
#define MEM_Ephem     0x0100   /* Mem.z points to an ephemeral string */
#define MEM_Short     0x0200   /* Mem.z points to Mem.zShort */
#define MEM_Agg       0x0400   /* Mem.z points to an agg function context */
#define MEM_Zero      0x0800   /* Mem.i contains count of 0s appended to blob */

#ifdef SQLITE_OMIT_INCRBLOB
  #undef MEM_Zero
  #define MEM_Zero 0x0000
#endif


/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
** additional information about auxiliary information bound to arguments
** of the function.  This is used to implement the sqlite3_get_auxdata()
** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
** that can be associated with a constant argument to a function.  This
** allows functions such as "regexp" to compile their constant regular

int sqlite3VdbeMemMove(Mem*, Mem*);
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*);

  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
#endif
int sqlite3VdbeMemHandleBom(Mem *pMem);
void sqlite3VdbeFifoInit(Fifo*);
int sqlite3VdbeFifoPush(Fifo*, i64);
int sqlite3VdbeFifoPop(Fifo*, i64*);
void sqlite3VdbeFifoClear(Fifo*);

#ifndef SQLITE_OMIT_INCRBLOB
  int sqlite3VdbeMemExpandBlob(Mem *);
#else
  #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
#endif

#endif /* !defined(_VDBEINT_H_) */

  return SQLITE_OK;
}

/*
** If the given Mem* has a zero-filled tail, turn it into an ordinary
** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
int sqlite3VdbeMemExpandBlob(Mem *pMem){
  if( pMem->flags & MEM_Zero ){
    char *pNew;
    assert( (pMem->flags & MEM_Blob)!=0 );
    pNew = sqliteMalloc(pMem->n+pMem->u.i);
    if( pNew==0 ){ 
      return SQLITE_NOMEM;
    }
    memcpy(pNew, pMem->z, pMem->n);
    memset(&pNew[pMem->n], 0, pMem->u.i);
    sqlite3VdbeMemRelease(pMem);
    pMem->z = pNew;
    pMem->n += pMem->u.i;
    pMem->u.i = 0;
    pMem->flags &= ~(MEM_Zero|MEM_Static|MEM_Ephem|MEM_Short|MEM_Term);
    pMem->flags |= MEM_Dyn;
  }
  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.