SQLite

**
** 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 1.872 2009/07/14 18:35:45 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test

    if( rc ) goto abort_due_to_error;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->cacheStatus==p->cacheCtr ){
      payloadSize = pC->payloadSize;
      zRec = (char*)pC->aRow;
    }else if( pC->isIndex ){
      rc = sqlite3BtreeKeySize(pCrsr, &payloadSize64);
      assert( rc==SQLITE_OK );   /* True because of CursorMoveto() call above */
      /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
      ** payload size, so it is impossible for payloadSize64 to be
      ** larger than 32 bits. */
      assert( (payloadSize64 & SQLITE_MAX_U32)==(u64)payloadSize64 );
      payloadSize = (u32)payloadSize64;
    }else{
      rc = sqlite3BtreeDataSize(pCrsr, &payloadSize);
      assert( rc==SQLITE_OK );   /* True because of CursorMoveto() call above */
    }
  }else if( pC->pseudoTable ){
    /* The record is the sole entry of a pseudo-table */
    payloadSize = pC->nData;
    zRec = pC->pData;
    pC->cacheStatus = CACHE_STALE;
    assert( payloadSize==0 || zRec!=0 );

        rc = sqlite3BtreeLast(pC->pCursor, &res);
        if( rc!=SQLITE_OK ){
          goto abort_due_to_error;
        }
        if( res ){
          v = 1;
        }else{
          rc = sqlite3BtreeKeySize(pC->pCursor, &v);
          assert( rc==SQLITE_OK );   /* Cannot fail following BtreeLast() */
          if( v==MAX_ROWID ){
            pC->useRandomRowid = 1;
          }else{
            v++;
          }
        }
      }

  */
  assert( pC->deferredMoveto==0 );
  rc = sqlite3VdbeCursorMoveto(pC);
  if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  if( pC->isIndex ){
    assert( !pC->isTable );
    rc = sqlite3BtreeKeySize(pCrsr, &n64);
    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
    if( n64>db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
    n = (u32)n64;
  }else{
    rc = sqlite3BtreeDataSize(pCrsr, &n);
    assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
    if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
      goto too_big;
    }
  }
  if( sqlite3VdbeMemGrow(pOut, n, 0) ){
    goto no_mem;
  }

  }else{
    assert( pC->pCursor!=0 );
    rc = sqlite3VdbeCursorMoveto(pC);
    if( rc ) goto abort_due_to_error;
    if( pC->rowidIsValid ){
      v = pC->lastRowid;
    }else{
      rc = sqlite3BtreeKeySize(pC->pCursor, &v);
      assert( rc==SQLITE_OK );  /* Always so because of CursorMoveto() above */
    }
  }
  pOut->u.i = v;
  MemSetTypeFlag(pOut, MEM_Int);
  break;
}

**
*************************************************************************
** This file contains code used for creating, destroying, and populating
** a VDBE (or an "sqlite3_stmt" 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.
**
** $Id: vdbeaux.c,v 1.474 2009/07/14 18:35:46 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"



/*

  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  
  */
  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 */
  m.flags = 0;
  m.db = db;
  m.zMalloc = 0;
  rc = sqlite3VdbeMemFromBtree(pCur, 0, (int)nCellKey, 1, &m);

  int *res                    /* Write the comparison result here */
){
  i64 nCellKey = 0;
  int rc;
  BtCursor *pCur = pC->pCursor;
  Mem m;

  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 say
  ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
  if( nCellKey<=0 || nCellKey>0x7fffffff ){
    *res = 0;
    return SQLITE_CORRUPT;
  }
  m.db = 0;
  m.flags = 0;
  m.zMalloc = 0;
  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (int)nCellKey, 1, &m);