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 */
- /* L{ser n{sta post med samma isam-nyckel */
- #include "isamdef.h"
- /*
- L{ser n{sta post med samma isamnyckel som f|reg}ende l{sning.
- Man kan ha gjort write, update eller delete p} f|reg}ende post.
- OBS! [ven om man {ndrade isamnyckeln p} f|reg}ende post l{ses
- posten i avseende p} f|reg}ende isam-nyckel-l{sning !!
- */
- int nisam_rnext(N_INFO *info, byte *buf, int inx)
- {
- int error,changed;
- uint flag;
- DBUG_ENTER("nisam_rnext");
- if ((inx = _nisam_check_index(info,inx)) < 0)
- DBUG_RETURN(-1);
- flag=SEARCH_BIGGER; /* Read next */
- if (info->lastpos == NI_POS_ERROR && info->update & HA_STATE_PREV_FOUND)
- flag=0; /* Read first */
- #ifndef NO_LOCKING
- if (_nisam_readinfo(info,F_RDLCK,1)) DBUG_RETURN(-1);
- #endif
- changed=_nisam_test_if_changed(info);
- if (!flag)
- error=_nisam_search_first(info,info->s->keyinfo+inx,
- info->s->state.key_root[inx]);
- else if (!changed)
- error=_nisam_search_next(info,info->s->keyinfo+inx,info->lastkey,flag,
- info->s->state.key_root[inx]);
- else
- error=_nisam_search(info,info->s->keyinfo+inx,info->lastkey,0,flag,
- info->s->state.key_root[inx]);
- /* Don't clear if database-changed */
- info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED |
- HA_STATE_BUFF_SAVED);
- info->update|= HA_STATE_NEXT_FOUND;
- if (error && my_errno == HA_ERR_KEY_NOT_FOUND)
- my_errno=HA_ERR_END_OF_FILE;
- if ((*info->read_record)(info,info->lastpos,buf) >=0)
- {
- info->update|= HA_STATE_AKTIV; /* Record is read */
- DBUG_RETURN(0);
- }
- DBUG_RETURN(-1);
- } /* nisam_rnext */