hp_open.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:3k
- /* 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 heap-database */
- #include "heapdef.h"
- #ifdef VMS
- #include "hp_static.c" /* Stupid vms-linker */
- #endif
- #include "my_sys.h"
- HP_INFO *heap_open(const char *name, int mode)
- {
- HP_INFO *info;
- HP_SHARE *share;
- DBUG_ENTER("heap_open");
- pthread_mutex_lock(&THR_LOCK_heap);
- if (!(share= hp_find_named_heap(name)))
- {
- my_errno= ENOENT;
- pthread_mutex_unlock(&THR_LOCK_heap);
- DBUG_RETURN(0);
- }
- if (!(info= (HP_INFO*) my_malloc((uint) sizeof(HP_INFO) +
- 2 * share->max_key_length,
- MYF(MY_ZEROFILL))))
- {
- pthread_mutex_unlock(&THR_LOCK_heap);
- DBUG_RETURN(0);
- }
- share->open_count++;
- #ifdef THREAD
- thr_lock_data_init(&share->lock,&info->lock,NULL);
- #endif
- info->open_list.data= (void*) info;
- heap_open_list= list_add(heap_open_list,&info->open_list);
- pthread_mutex_unlock(&THR_LOCK_heap);
- info->s= share;
- info->lastkey= (byte*) (info + 1);
- info->recbuf= (byte*) (info->lastkey + share->max_key_length);
- info->mode= mode;
- info->current_record= (ulong) ~0L; /* No current record */
- info->current_ptr= 0;
- info->current_hash_ptr= 0;
- info->lastinx= info->errkey= -1;
- info->update= 0;
- #ifndef DBUG_OFF
- info->opt_flag= READ_CHECK_USED; /* Check when changing */
- #endif
- DBUG_PRINT("exit",("heap: %lx reclength: %d records_in_block: %d",
- info,share->reclength,share->block.records_in_block));
- DBUG_RETURN(info);
- }
- /* map name to a heap-nr. If name isn't found return 0 */
- HP_SHARE *hp_find_named_heap(const char *name)
- {
- LIST *pos;
- HP_SHARE *info;
- DBUG_ENTER("heap_find");
- DBUG_PRINT("enter",("name: %s",name));
- for (pos= heap_share_list; pos; pos= pos->next)
- {
- info= (HP_SHARE*) pos->data;
- if (!strcmp(name, info->name))
- {
- DBUG_PRINT("exit", ("Old heap_database: %lx",info));
- DBUG_RETURN(info);
- }
- }
- DBUG_RETURN((HP_SHARE *) 0);
- }