** 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: btree.c,v 1.184 2004/08/31 13:45:11 drh 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.
................................................................................
  MemPage *pPage;           /* Page that contains the entry */
  int idx;                  /* Index of the entry in pPage->aCell[] */
  CellInfo info;            /* A parse of the cell we are pointing at */
  u8 wrFlag;                /* True if writable */
  u8 isValid;               /* TRUE if points to a valid entry */
  u8 status;                /* Set to SQLITE_ABORT if cursors is invalidated */
};







/*
** Read or write a two- and four-byte big-endian integer values.
*/
static u32 get2byte(unsigned char *p){
  return (p[0]<<8) | p[1];
}
................................................................................
  BtCursor **ppCur                            /* Write new cursor here */
){
  int rc;
  BtCursor *pCur;

  *ppCur = 0;
  if( wrFlag ){
    static int checkReadLocks(Btree*,Pgno,BtCursor*);
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(pBt, iTable, 0) ){
      return SQLITE_LOCKED;
    }
  }

** 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: btree.c,v 1.185 2004/09/01 16:12:25 drh 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.
................................................................................
  MemPage *pPage;           /* Page that contains the entry */
  int idx;                  /* Index of the entry in pPage->aCell[] */
  CellInfo info;            /* A parse of the cell we are pointing at */
  u8 wrFlag;                /* True if writable */
  u8 isValid;               /* TRUE if points to a valid entry */
  u8 status;                /* Set to SQLITE_ABORT if cursors is invalidated */
};

/*
** Forward declaration
*/
static int checkReadLocks(Btree*,Pgno,BtCursor*);


/*
** Read or write a two- and four-byte big-endian integer values.
*/
static u32 get2byte(unsigned char *p){
  return (p[0]<<8) | p[1];
}
................................................................................
  BtCursor **ppCur                            /* Write new cursor here */
){
  int rc;
  BtCursor *pCur;

  *ppCur = 0;
  if( wrFlag ){

    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(pBt, iTable, 0) ){
      return SQLITE_LOCKED;
    }
  }