~drizzle-trunk/drizzle/development

/* Copyright (C) 2000-2002, 2004 MySQL AB

   This program 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; version 2 of the License.

   This program 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 this program; if not, write to the Free Software

   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "heap_priv.h"

#include <string.h>

#include <cassert>

using namespace drizzled;

/* Read first record with the current key */

int heap_rfirst(HP_INFO *info, unsigned char *record, int inx)

{

  HP_SHARE *share = info->s;

  HP_KEYDEF *keyinfo = share->keydef + inx;

  info->lastinx= inx;

  if (keyinfo->algorithm == HA_KEY_ALG_BTREE)

  {

    unsigned char *pos;

    if ((pos = (unsigned char *)tree_search_edge(&keyinfo->rb_tree,

                                                 info->parents,

                                                 &info->last_pos,

                                                 offsetof(TREE_ELEMENT, left))))

    {

      memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos),

	     sizeof(unsigned char*));

      info->current_ptr = pos;

      hp_extract_record(share, record, pos);

      /*

        If we're performing index_first on a table that was taken from

        table cache, info->lastkey_len is initialized to previous query.

        Thus we set info->lastkey_len to proper value for subsequent

        heap_rnext() calls.

        This is needed for DELETE queries only, otherwise this variable is

        not used.

        Note that the same workaround may be needed for heap_rlast(), but

        for now heap_rlast() is never used for DELETE queries.

      */

      info->lastkey_len= 0;

      info->update = HA_STATE_AKTIV;

    }

    else

    {

      errno = HA_ERR_END_OF_FILE;

      return(errno);

    }

    return(0);

  }

  else

  {

    if (!(info->s->records))

    {

      errno=HA_ERR_END_OF_FILE;

      return(errno);

    }

    assert(0); /* TODO fix it */

    info->current_record=0;

    info->current_hash_ptr=0;

    info->update=HA_STATE_PREV_FOUND;

    return(heap_rnext(info,record));

  }

}