hp_rlast.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:2k
- /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
- (at your option) any later version.
- 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 "heapdef.h"
- /* Read first record with the current key */
- int heap_rlast(HP_INFO *info, byte *record, int inx)
- {
- HP_SHARE *share= info->s;
- HP_KEYDEF *keyinfo= share->keydef + inx;
- DBUG_ENTER("heap_rlast");
- info->lastinx= inx;
- if (keyinfo->algorithm == HA_KEY_ALG_BTREE)
- {
- byte *pos;
- if ((pos = tree_search_edge(&keyinfo->rb_tree, info->parents,
- &info->last_pos, offsetof(TREE_ELEMENT, right))))
- {
- memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos),
- sizeof(byte*));
- info->current_ptr = pos;
- memcpy(record, pos, (size_t)share->reclength);
- info->update = HA_STATE_AKTIV;
- }
- else
- {
- my_errno = HA_ERR_END_OF_FILE;
- DBUG_RETURN(my_errno);
- }
- DBUG_RETURN(0);
- }
- else
- {
- info->current_ptr=0;
- info->current_hash_ptr=0;
- info->update=HA_STATE_NEXT_FOUND;
- DBUG_RETURN(heap_rprev(info,record));
- }
- }