SQLite4  Check-in [88c8fd489d]

*/
int sqlite4BtCsrFirst(bt_cursor *pCsr);
int sqlite4BtCsrLast(bt_cursor *pCsr);

int sqlite4BtCsrNext(bt_cursor *pCsr);
int sqlite4BtCsrPrev(bt_cursor *pCsr);


int sqlite4BtCsrKey(bt_cursor *pCsr, const void **ppK, int *pnK);
int sqlite4BtCsrData(bt_cursor *pCsr, int, int, const void **ppV, int *pnV);

int sqlite4BtReplace(bt_db*, const void *pK, int nK, const void *pV, int nV);
int sqlite4BtDelete(bt_cursor*);

int sqlite4BtSetCookie(bt_db*, unsigned int iVal);

  }

  return pgno;
}


#ifndef NDEBUG
#include <stdio.h>
static void printPage(u8 *aData, int nData){
  int i;
  int nCell = (int)btCellCount(aData, nData);
  fprintf(stderr, "nCell=%d\n", nCell);
  fprintf(stderr, "iFree=%d\n", (int)btFreeOffset(aData, nData));
  fprintf(stderr, "flags=%d\n", (int)btFlags(aData, nData));
  fprintf(stderr, "cell offsets:");
  for(i=0; i<nCell; i++){
    fprintf(stderr, " %d", btCellFind(aData, nData, i) - aData);
  }
  fprintf(stderr, "\n");
}
#endif














































/*
** This function compares the key passed via parameters pK and nK to the
** key stored as part of cell iCell on the database page stored in buffer
** aData (size nData bytes).
**
** If the cell key is C, and the user key K, then this function sets:
**

        }
      }
    }
  }

  return rc;
}

/*
** This function seeks the cursor as required for either sqlite4BtCsrFirst()
** (if parameter bLast is false) or sqlite4BtCsrLast() (if bLast is true).
*/
static int btCsrEnd(bt_cursor *pCsr, int bLast){
  const int pgsz = sqlite4BtPagerPagesize(pCsr->pDb->pPager);
  int rc;                         /* Return Code */
  u32 pgno;                       /* Page number for next page to load */

  /* Reset the cursor */
  btCsrReset(pCsr);

  /* Figure out the root page number */
  assert( pCsr->nPg==0 );
  pgno = sqlite4BtPagerRootpgno(pCsr->pDb->pPager);

  while( rc==SQLITE4_OK ){
    /* Load page number pgno into the b-tree */
    rc = btCsrDescend(pCsr, pgno);
    if( rc==SQLITE4_OK ){
      int nByte;
      u8 *pCell;
      u8 *aData = (u8*)sqlite4BtPageData(pCsr->apPage[pCsr->nPg-1]);

      /* If the cursor has descended to a leaf break out of the loop. */
      pCsr->aiCell[pCsr->nPg-1] = (bLast ? btCellCount(aData, pgsz) : 0);
      if( (aData[0] & BT_PGFLAGS_INTERNAL)==0 ) break;
      
      /* Otherwise, set pgno to the left or rightmost child of the page
      ** just loaded, depending on whether the cursor is seeking to the
      ** start or end of the tree.  */
      if( bLast==0 ){
        pCell = btCellFind(aData, pgsz, 0);
        pCell += sqlite4BtVarintGet32(pCell, &nByte);
        pCell += nByte;
        sqlite4BtVarintGet32(pCell, (int *)&pgno);
      }else{
        pgno = btGetU32(&aData[1]);
      }
    }
  }
  return rc;
}

/*
** Position cursor pCsr to point to the smallest key in the database.
*/
int sqlite4BtCsrFirst(bt_cursor *pCsr){
  return btCsrEnd(pCsr, 0);
}

/*
** Retreat to the previous entry in the tree.
*/
int sqlite4BtCsrPrev(bt_cursor *pCsr){
  return btCsrStep(pCsr, 0);
}






int sqlite4BtCsrKey(bt_cursor *pCsr, const void **ppK, int *pnK){
  const int pgsz = sqlite4BtPagerPagesize(pCsr->pDb->pPager);
  u8 *aData;
  u8 *pCell;
  int iCell = pCsr->aiCell[pCsr->nPg-1];
  int nK;
  

    nFree = pgsz - btFreeOffset(aData, pgsz) - (2+nCell) * 2;
  }
  if( nFree>=nReq ){
    rc = sqlite4BtPageWrite(pLeaf);
    if( rc==SQLITE4_OK ){
      aData = sqlite4BtPageData(pLeaf);




      /* Update the cell pointer array */
      if( iCell!=nCell ){
        u8 *aFrom = btCellPtrFind(aData, pgsz, nCell-1);
        u8 *aTo = btCellPtrFind(aData, pgsz, nCell);
        memmove(aTo, aFrom, (nCell-iCell) * 2);
      }
      btPutU16(btCellPtrFind(aData, pgsz, iCell), iWrite);

      /* Increase cell count */
      btPutU16(&aData[pgsz-2], nCell+1);
      
      /* Write the cell itself */
      iWrite += sqlite4BtVarintPut32(&aData[iWrite], nK);
      memcpy(&aData[iWrite], pK, nK); 
      iWrite += nK;
      iWrite += sqlite4BtVarintPut32(&aData[iWrite], nV);
      memcpy(&aData[iWrite], pV, nV); 

do_test 1.0 {
  sqlite4 db file:test.db?kv=bt
  db close
} {}

do_test 1.1 { sqlite4 db file:test.db?kv=bt } {}

do_execsql_test 1.2 { 
  CREATE TABLE t1(a, b) 
} 

do_execsql_test 1.3 {
  SELECT * FROM sqlite_master;
} {table t1 t1 2 {CREATE TABLE t1(a, b)}}

do_execsql_test 1.4 {
  INSERT INTO t1 VALUES('abc', 'def');
  INSERT INTO t1 VALUES('ghi', 'jkl');
} {}

do_execsql_test 1.5 {
  SELECT rowid, a, b FROM t1;
} {1 abc def 2 ghi jkl}

do_execsql_test 1.6 {
  UPDATE t1 SET b = 5;
}

do_execsql_test 1.7 {
  SELECT rowid, a, b FROM t1;
} {1 abc 5 2 ghi 5}

finish_test