update.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /* 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 */
- /* Uppdaterare nuvarande record i en pisam-databas */
- #include "isamdef.h"
- #ifdef __WIN__
- #include <errno.h>
- #endif
- /* Updaterar senaste l{sta record i databasen */
- int nisam_update(register N_INFO *info, const byte *oldrec, const byte *newrec)
- {
- int flag,key_changed,save_errno;
- reg3 ulong pos;
- uint i,length;
- uchar old_key[N_MAX_KEY_BUFF],*new_key;
- DBUG_ENTER("nisam_update");
- LINT_INIT(save_errno);
- if (!(info->update & HA_STATE_AKTIV))
- {
- my_errno=HA_ERR_KEY_NOT_FOUND;
- DBUG_RETURN(-1);
- }
- if (info->s->base.options & HA_OPTION_READ_ONLY_DATA)
- {
- my_errno=EACCES;
- DBUG_RETURN(-1);
- }
- pos=info->lastpos;
- #ifndef NO_LOCKING
- if (_nisam_readinfo(info,F_WRLCK,1)) DBUG_RETURN(-1);
- #endif
- if ((*info->s->compare_record)(info,oldrec))
- {
- save_errno=my_errno;
- goto err_end; /* Record has changed */
- }
- if (info->s->state.key_file_length >=
- info->s->base.max_key_file_length -
- info->s->blocksize* INDEX_BLOCK_MARGIN *info->s->state.keys)
- {
- save_errno=HA_ERR_INDEX_FILE_FULL;
- goto err_end;
- }
- /* Flyttar de element i isamfilen som m}ste flyttas */
- new_key=info->lastkey+info->s->base.max_key_length;
- key_changed=HA_STATE_KEY_CHANGED; /* We changed current database */
- /* Remove key that didn't change */
- for (i=0 ; i < info->s->state.keys ; i++)
- {
- length=_nisam_make_key(info,i,new_key,newrec,pos);
- if (length != _nisam_make_key(info,i,old_key,oldrec,pos) ||
- memcmp((byte*) old_key,(byte*) new_key,length))
- {
- if ((int) i == info->lastinx)
- key_changed|=HA_STATE_WRITTEN; /* Mark that keyfile changed */
- if (_nisam_ck_delete(info,i,old_key)) goto err;
- if (_nisam_ck_write(info,i,new_key)) goto err;
- }
- }
- if ((*info->s->update_record)(info,pos,newrec))
- goto err;
- info->update= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED | HA_STATE_AKTIV |
- key_changed);
- nisam_log_record(LOG_UPDATE,info,newrec,info->lastpos,0);
- VOID(_nisam_writeinfo(info,test(key_changed)));
- allow_break(); /* Allow SIGHUP & SIGINT */
- DBUG_RETURN(0);
- err:
- DBUG_PRINT("error",("key: %d errno: %d",i,my_errno));
- save_errno=my_errno;
- if (my_errno == HA_ERR_FOUND_DUPP_KEY || my_errno == HA_ERR_RECORD_FILE_FULL)
- {
- info->errkey= (int) i;
- flag=0;
- do
- {
- length=_nisam_make_key(info,i,new_key,newrec,pos);
- if (length != _nisam_make_key(info,i,old_key,oldrec,pos) ||
- memcmp((byte*) old_key,(byte*) new_key,length))
- {
- if ((flag++ && _nisam_ck_delete(info,i,new_key)) ||
- _nisam_ck_write(info,i,old_key))
- break;
- }
- } while (i-- != 0);
- }
- info->update= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED | HA_STATE_AKTIV |
- key_changed);
- err_end:
- nisam_log_record(LOG_UPDATE,info,newrec,info->lastpos,save_errno);
- VOID(_nisam_writeinfo(info,1));
- allow_break(); /* Allow SIGHUP & SIGINT */
- my_errno=(save_errno == HA_ERR_KEY_NOT_FOUND) ? HA_ERR_CRASHED : save_errno;
- DBUG_RETURN(-1);
- } /* nisam_update */