mrg_open.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 */
- /* open a MERGE-database */
- #include "mrg_def.h"
- #include <stddef.h>
- #include <errno.h>
- #ifdef VMS
- #include "static.c"
- #endif
- /* open a MERGE-database.
- if handle_locking is 0 then exit with error if some database is locked
- if handle_locking is 1 then wait if database is locked
- */
- MRG_INFO *mrg_open(
- const char *name,
- int mode,
- int handle_locking)
- {
- int save_errno,i,errpos;
- uint files,dir_length,length, options;
- ulonglong file_offset;
- char name_buff[FN_REFLEN*2],buff[FN_REFLEN],*end;
- MRG_INFO info,*m_info;
- File fd;
- IO_CACHE file;
- N_INFO *isam,*last_isam;
- DBUG_ENTER("mrg_open");
- LINT_INIT(last_isam);
- isam=0;
- errpos=files=0;
- bzero((gptr) &info,sizeof(info));
- bzero((char*) &file,sizeof(file));
- if ((fd=my_open(fn_format(name_buff,name,"",MRG_NAME_EXT,4),
- O_RDONLY | O_SHARE,MYF(0))) < 0 ||
- init_io_cache(&file, fd, IO_SIZE, READ_CACHE, 0, 0,
- MYF(MY_WME | MY_NABP)))
- goto err;
- errpos=1;
- dir_length=dirname_part(name_buff,name);
- info.reclength=0;
- while ((length=my_b_gets(&file,buff,FN_REFLEN-1)))
- {
- if ((end=buff+length)[-1] == 'n')
- end[-1]=' ';
- if (buff[0] && buff[0] != '#') /* Skip empty lines and comments */
- {
- last_isam=isam;
- if (!test_if_hard_path(buff))
- {
- VOID(strmake(name_buff+dir_length,buff,
- sizeof(name_buff)-1-dir_length));
- VOID(cleanup_dirname(buff,name_buff));
- }
- if (!(isam=nisam_open(buff,mode,test(handle_locking))))
- goto err;
- files++;
- }
- last_isam=isam;
- if (info.reclength && info.reclength != isam->s->base.reclength)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- info.reclength=isam->s->base.reclength;
- }
- if (!(m_info= (MRG_INFO*) my_malloc(sizeof(MRG_INFO)+files*sizeof(MRG_TABLE),
- MYF(MY_WME))))
- goto err;
- *m_info=info;
- m_info->open_tables=(MRG_TABLE *) (m_info+1);
- m_info->tables=files;
- options= (uint) ~0;
- for (i=files ; i-- > 0 ; )
- {
- m_info->open_tables[i].table=isam;
- m_info->options|=isam->s->base.options;
- options&=isam->s->base.options;
- m_info->records+=isam->s->state.records;
- m_info->del+=isam->s->state.del;
- m_info->data_file_length=isam->s->state.data_file_length;
- if (i)
- isam=(N_INFO*) (isam->open_list.next->data);
- }
- /* Don't force readonly if not all tables are readonly */
- if (! (options & (HA_OPTION_COMPRESS_RECORD | HA_OPTION_READ_ONLY_DATA)))
- m_info->options&= ~(HA_OPTION_COMPRESS_RECORD | HA_OPTION_READ_ONLY_DATA);
- /* Fix fileinfo for easyer debugging (actually set by rrnd) */
- file_offset=0;
- for (i=0 ; (uint) i < files ; i++)
- {
- m_info->open_tables[i].file_offset=(my_off_t) file_offset;
- file_offset+=m_info->open_tables[i].table->s->state.data_file_length;
- }
- if (sizeof(my_off_t) == 4 && file_offset > (ulonglong) (ulong) ~0L)
- {
- my_errno=HA_ERR_RECORD_FILE_FULL;
- my_free((char*) m_info,MYF(0));
- goto err;
- }
- m_info->end_table=m_info->open_tables+files;
- m_info->last_used_table=m_info->open_tables;
- VOID(my_close(fd,MYF(0)));
- end_io_cache(&file);
- m_info->open_list.data=(void*) m_info;
- pthread_mutex_lock(&THR_LOCK_open);
- mrg_open_list=list_add(mrg_open_list,&m_info->open_list);
- pthread_mutex_unlock(&THR_LOCK_open);
- DBUG_RETURN(m_info);
- err:
- save_errno=my_errno;
- switch (errpos) {
- case 1:
- VOID(my_close(fd,MYF(0)));
- end_io_cache(&file);
- for (i=files ; i-- > 0 ; )
- {
- isam=last_isam;
- if (i)
- last_isam=(N_INFO*) (isam->open_list.next->data);
- nisam_close(isam);
- }
- }
- my_errno=save_errno;
- DBUG_RETURN (NULL);
- }