/* dbmseq.c - Visit all elements in the database.  This is the NDBM
   interface. */

/* This file is part of GDBM, the GNU data base manager.
   Copyright (C) 1990-1991, 1993, 2007, 2011, 2017-2018 Free Software
   Foundation, Inc.

   GDBM is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GDBM is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GDBM. If not, see <http://www.gnu.org/licenses/>.    */

/* Include system configuration before all else. */
#include "autoconf.h"
#include "ndbm.h"
#include "gdbmdefs.h"

/* NDBM Start the visit of all keys in the database.  This produces
   something in hash order, not in any sorted order.  DBF is the dbm file
   information pointer. */

datum
dbm_firstkey (DBM *dbm)
{
  datum ret_val;

  /* Free previous dynamic memory, do actual call, and save pointer to new
     memory. */
  ret_val = gdbm_firstkey (dbm->file);
  if (dbm->_dbm_memory.dptr != NULL)
    free (dbm->_dbm_memory.dptr);
  dbm->_dbm_memory = ret_val;
  __gdbm_error_to_ndbm (dbm);
  /* Return the new value. */
  return ret_val;
}


/* NDBM Continue visiting all keys.  The next key in the sequence is returned.
   DBF is the file information pointer. */

datum
dbm_nextkey (DBM *dbm)
{
  datum ret_val;

  /* Make sure we have a valid key. */
  if (dbm->_dbm_memory.dptr == NULL)
    return dbm->_dbm_memory;

  /* Call gdbm nextkey with the old value. After that, free the old value. */
  ret_val = gdbm_nextkey (dbm->file, dbm->_dbm_memory);
  if (dbm->_dbm_memory.dptr != NULL)
    free (dbm->_dbm_memory.dptr);
  dbm->_dbm_memory = ret_val;
  __gdbm_error_to_ndbm (dbm);
  /* Return the new value. */
  return ret_val;
}