myrg_open.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:5k
- /* 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 MyISAM MERGE table */
- #include "myrg_def.h"
- #include <stddef.h>
- #include <errno.h>
- #ifdef VMS
- #include "mrg_static.c"
- #endif
- /*
- open a MyISAM MERGE table
- if handle_locking is 0 then exit with error if some table is locked
- if handle_locking is 1 then wait if table is locked
- */
- MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
- {
- int save_errno,errpos=0;
- uint files=0,i,dir_length,length,key_parts;
- ulonglong file_offset=0;
- char name_buff[FN_REFLEN*2],buff[FN_REFLEN],*end;
- MYRG_INFO *m_info=0;
- File fd;
- IO_CACHE file;
- MI_INFO *isam=0;
- uint found_merge_insert_method= 0;
- DBUG_ENTER("myrg_open");
- LINT_INIT(key_parts);
- bzero((char*) &file,sizeof(file));
- if ((fd=my_open(fn_format(name_buff,name,"",MYRG_NAME_EXT,4),
- O_RDONLY | O_SHARE,MYF(0))) < 0)
- goto err;
- errpos=1;
- if (init_io_cache(&file, fd, 4*IO_SIZE, READ_CACHE, 0, 0,
- MYF(MY_WME | MY_NABP)))
- goto err;
- errpos=2;
- dir_length=dirname_part(name_buff,name);
- while ((length=my_b_gets(&file,buff,FN_REFLEN-1)))
- {
- if ((end=buff+length)[-1] == 'n')
- end[-1]=' ';
- if (buff[0] && buff[0] != '#')
- files++;
- }
- my_b_seek(&file, 0);
- while ((length=my_b_gets(&file,buff,FN_REFLEN-1)))
- {
- if ((end=buff+length)[-1] == 'n')
- *--end=' ';
- if (!buff[0])
- continue; /* Skip empty lines */
- if (buff[0] == '#')
- {
- if (!strncmp(buff+1,"INSERT_METHOD=",14))
- { /* Lookup insert method */
- int tmp=find_type(buff+15,&merge_insert_method,2);
- found_merge_insert_method = (uint) (tmp >= 0 ? tmp : 0);
- }
- continue; /* Skip comments */
- }
- if (!has_path(buff))
- {
- VOID(strmake(name_buff+dir_length,buff,
- sizeof(name_buff)-1-dir_length));
- VOID(cleanup_dirname(buff,name_buff));
- }
- else
- fn_format(buff, buff, "", "", 0);
- if (!(isam=mi_open(buff,mode,(handle_locking?HA_OPEN_WAIT_IF_LOCKED:0))))
- goto err;
- if (!m_info) /* First file */
- {
- key_parts=isam->s->base.key_parts;
- if (!(m_info= (MYRG_INFO*) my_malloc(sizeof(MYRG_INFO) +
- files*sizeof(MYRG_TABLE) +
- key_parts*sizeof(long),
- MYF(MY_WME|MY_ZEROFILL))))
- goto err;
- if (files)
- {
- m_info->open_tables=(MYRG_TABLE *) (m_info+1);
- m_info->rec_per_key_part=(ulong *) (m_info->open_tables+files);
- m_info->tables= files;
- files= 0;
- }
- m_info->reclength=isam->s->base.reclength;
- errpos=3;
- }
- m_info->open_tables[files].table= isam;
- m_info->open_tables[files].file_offset=(my_off_t) file_offset;
- file_offset+=isam->state->data_file_length;
- files++;
- if (m_info->reclength != isam->s->base.reclength)
- {
- my_errno=HA_ERR_WRONG_MRG_TABLE_DEF;
- goto err;
- }
- m_info->options|= isam->s->options;
- m_info->records+= isam->state->records;
- m_info->del+= isam->state->del;
- m_info->data_file_length+= isam->state->data_file_length;
- for (i=0; i < key_parts; i++)
- m_info->rec_per_key_part[i]+= (isam->s->state.rec_per_key_part[i] /
- m_info->tables);
- }
- if (!m_info && !(m_info= (MYRG_INFO*) my_malloc(sizeof(MYRG_INFO),
- MYF(MY_WME | MY_ZEROFILL))))
- goto err;
- /* Don't mark table readonly, for ALTER TABLE ... UNION=(...) to work */
- m_info->options&= ~(HA_OPTION_COMPRESS_RECORD | HA_OPTION_READ_ONLY_DATA);
- m_info->merge_insert_method= found_merge_insert_method;
- if (sizeof(my_off_t) == 4 && file_offset > (ulonglong) (ulong) ~0L)
- {
- my_errno=HA_ERR_RECORD_FILE_FULL;
- goto err;
- }
- m_info->keys= files ? isam->s->base.keys : 0;
- bzero((char*) &m_info->by_key,sizeof(m_info->by_key));
- /* this works ok if the table list is empty */
- 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);
- myrg_open_list=list_add(myrg_open_list,&m_info->open_list);
- pthread_mutex_unlock(&THR_LOCK_open);
- DBUG_RETURN(m_info);
- err:
- save_errno=my_errno;
- switch (errpos) {
- case 3:
- while (files)
- mi_close(m_info->open_tables[--files].table);
- my_free((char*) m_info,MYF(0));
- /* Fall through */
- case 2:
- end_io_cache(&file);
- /* Fall through */
- case 1:
- VOID(my_close(fd,MYF(0)));
- }
- my_errno=save_errno;
- DBUG_RETURN (NULL);
- }