myrg_rnext.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 "myrg_def.h"
- /*
- Read next row with the same key as previous read
- */
- int myrg_rnext(MYRG_INFO *info, byte *buf, int inx)
- {
- int err;
- MI_INFO *mi;
- if (!info->current_table)
- return (HA_ERR_KEY_NOT_FOUND);
- /* at first, do rnext for the table found before */
- if ((err=mi_rnext(info->current_table->table,NULL,inx)))
- {
- if (err == HA_ERR_END_OF_FILE)
- {
- queue_remove(&(info->by_key),0);
- if (!info->by_key.elements)
- return HA_ERR_END_OF_FILE;
- }
- else
- return err;
- }
- else
- {
- /* Found here, adding to queue */
- queue_top(&(info->by_key))=(byte *)(info->current_table);
- queue_replaced(&(info->by_key));
- }
- /* now, mymerge's read_next is as simple as one queue_top */
- mi=(info->current_table=(MYRG_TABLE *)queue_top(&(info->by_key)))->table;
- return _myrg_mi_read_record(mi,buf);
- }