mf_cache.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
- 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 temporary file and cache it with io_cache. Delete it on close */
- #include "mysys_priv.h"
- #include <m_string.h>
- #include "my_static.h"
- #include "mysys_err.h"
- /*
- Remove an open tempfile so that it doesn't survive
- if we crash; If the operating system doesn't support
- this, just remember the file name for later removal
- */
- static my_bool cache_remove_open_tmp(IO_CACHE *cache __attribute__((unused)),
- const char *name)
- {
- #if O_TEMPORARY == 0
- #if !defined(CANT_DELETE_OPEN_FILES)
- /* The following should always succeed */
- (void) my_delete(name,MYF(MY_WME | ME_NOINPUT));
- #else
- int length;
- if (!(cache->file_name=
- (char*) my_malloc((length=strlen(name)+1),MYF(MY_WME))))
- {
- my_close(cache->file,MYF(0));
- cache->file = -1;
- errno=my_errno=ENOMEM;
- return 1;
- }
- memcpy(cache->file_name,name,length);
- #endif
- #endif /* O_TEMPORARY == 0 */
- return 0;
- }
- /*
- ** Open tempfile cached by IO_CACHE
- ** Should be used when no seeks are done (only reinit_io_buff)
- ** Return 0 if cache is inited ok
- ** The actual file is created when the IO_CACHE buffer gets filled
- ** If dir is not given, use TMPDIR.
- */
- my_bool open_cached_file(IO_CACHE *cache, const char* dir, const char *prefix,
- uint cache_size, myf cache_myflags)
- {
- DBUG_ENTER("open_cached_file");
- cache->dir= dir ? my_strdup(dir,MYF(cache_myflags & MY_WME)) : (char*) 0;
- cache->prefix= (prefix ? my_strdup(prefix,MYF(cache_myflags & MY_WME)) :
- (char*) 0);
- cache->file_name=0;
- cache->buffer=0; /* Mark that not open */
- if (!init_io_cache(cache,-1,cache_size,WRITE_CACHE,0L,0,
- MYF(cache_myflags | MY_NABP)))
- {
- DBUG_RETURN(0);
- }
- my_free(cache->dir, MYF(MY_ALLOW_ZERO_PTR));
- my_free(cache->prefix,MYF(MY_ALLOW_ZERO_PTR));
- DBUG_RETURN(1);
- }
- /* Create the temporary file */
- my_bool real_open_cached_file(IO_CACHE *cache)
- {
- char name_buff[FN_REFLEN];
- int error=1;
- DBUG_ENTER("real_open_cached_file");
- if ((cache->file=create_temp_file(name_buff, cache->dir, cache->prefix,
- (O_RDWR | O_BINARY | O_TRUNC |
- O_TEMPORARY | O_SHORT_LIVED),
- MYF(MY_WME))) >= 0)
- {
- error=0;
- cache_remove_open_tmp(cache, name_buff);
- }
- DBUG_RETURN(error);
- }
- void close_cached_file(IO_CACHE *cache)
- {
- DBUG_ENTER("close_cached_file");
- if (my_b_inited(cache))
- {
- File file=cache->file;
- cache->file= -1; /* Don't flush data */
- (void) end_io_cache(cache);
- if (file >= 0)
- {
- (void) my_close(file,MYF(0));
- #ifdef CANT_DELETE_OPEN_FILES
- if (cache->file_name)
- {
- (void) my_delete(cache->file_name,MYF(MY_WME | ME_NOINPUT));
- my_free(cache->file_name,MYF(0));
- }
- #endif
- }
- my_free(cache->dir,MYF(MY_ALLOW_ZERO_PTR));
- my_free(cache->prefix,MYF(MY_ALLOW_ZERO_PTR));
- }
- DBUG_VOID_RETURN;
- }