SQLite

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.43 2004/05/09 23:23:57 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

int sqlite3BtreeEof(BtCursor*);
int sqlite3BtreePrevious(BtCursor*, int *pRes);
int sqlite3BtreeKeySize(BtCursor*, u64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
void *sqlite3BtreeKeyFetch(BtCursor*);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);


char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot);
struct Pager *sqlite3BtreePager(Btree*);

#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*);
void sqlite3BtreeCursorList(Btree*);
int sqlite3BtreeFlags(BtCursor*);
int sqlite3BtreePageDump(Btree*, int, int recursive);
#endif


#endif /* _BTREE_H_ */

**
** 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 1.271 2004/05/09 23:23:58 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

    if( res<0 ){
      rc = sqlite3BtreeNext(pCrsr, &res);
      if( res ){
        pc = pOp->p2 - 1;
        break;
      }
    }
    /* FIX ME - the sqlite2BtreeKeyCompare() function is a temporary hack */
    rc = sqlite2BtreeKeyCompare(pCrsr, zKey, nKey-4, 4, &res); 

    if( rc!=SQLITE_OK ) goto abort_due_to_error;
    if( res>0 ){
      pc = pOp->p2 - 1;
      break;
    }

    /* At this point, pCrsr is pointing to an entry in P1 where all but

      assert( nKey >= 4 );
      rc = sqlite3BtreeMoveto(pCrsr, zKey, nKey-4, &res);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
      while( res!=0 ){
        int c;
        /* TODO: sqlite3BtreeKeySize(pCrsr, &n); */
        if( n==nKey
     /* FIX ME - the sqlite2BtreeKeyCompare() function is a temporary hack */
            && sqlite2BtreeKeyCompare(pCrsr, zKey, nKey-4, 4, &c)==SQLITE_OK

           && c==0
        ){
          rc = SQLITE_CONSTRAINT;
          if( pOp->p3 && pOp->p3[0] ){
            sqlite3SetString(&p->zErrMsg, pOp->p3, (char*)0);
          }
          goto abort_due_to_error;

  assert( i>=0 && i<p->nCursor );
  assert( pTos>=p->aStack );
  if( (pCrsr = p->aCsr[i].pCursor)!=0 ){
    int res, rc;
 
    Stringify(pTos);
    assert( p->aCsr[i].deferredMoveto==0 );
    /* FIX ME - the sqlite2BtreeKeyCompare() function is a temporary hack */
    rc = sqlite2BtreeKeyCompare(pCrsr, pTos->z, pTos->n, 4, &res);

    if( rc!=SQLITE_OK ){
      break;
    }
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
    }else if( pOp->opcode==OP_IdxGE ){
      res++;

void sqlite3VdbeKeylistFree(Keylist*);
void sqliteVdbePopStack(Vdbe*,int);
int sqlite3VdbeCursorMoveto(Cursor*);
int sqlite3VdbeByteSwap(int);
#if !defined(NDEBUG) || defined(VDBE_PROFILE)
void sqlite3VdbePrintOp(FILE*, int, Op*);
#endif

int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);

    }
    sqlite_search_count++;
    p->deferredMoveto = 0;
  }
  return SQLITE_OK;
}

/*
** FIX ME
**
** This function is included temporarily so that regression tests have
** a chance of passing. It always uses memcmp().
*/
int sqlite2BtreeKeyCompare(
  BtCursor *pCur,       /* Pointer to entry to compare against */
  const void *pKey,     /* Key to compare against entry that pCur points to */
  int nKey,             /* Number of bytes in pKey */
  int nIgnore,          /* Ignore this many bytes at the end of pCur */
  int *pResult          /* Write the result here */
){
  void *pCellKey;
  u64 nCellKey;
  int rc;

  sqlite3BtreeKeySize(pCur, &nCellKey);
  nCellKey = nCellKey - nIgnore;
  if( nCellKey<=0 ){
    *pResult = 0;
    return SQLITE_OK;
  }

  pCellKey = sqlite3BtreeKeyFetch(pCur);
  if( pCellKey ){
    *pResult = memcmp(pCellKey, pKey, nKey>nCellKey?nCellKey:nKey);
    return SQLITE_OK;
  }

  pCellKey = sqliteMalloc( nCellKey );
  if( pCellKey==0 ) return SQLITE_NOMEM;

  rc = sqlite3BtreeKey(pCur, 0, nCellKey, pCellKey);
  *pResult = memcmp(pCellKey, pKey, nKey>nCellKey?nCellKey:nKey);
  sqliteFree(pCellKey);

  return rc;
}

/*
** The following is the comparison function for (non-integer)
** keys in the btrees.  This function returns negative, zero, or
** positive if the first key is less than, equal to, or greater than
** the second.
**