mariadb/mysys/mf_cache.c
Sergey Vojtovich 974808772b MDEV-7004 - Merge scalability fixes from 10.0-power
All callers of open_cached_file() use 2 characters prefix. Allocating memory for
such short string is an overkill. Store it on IO_CACHE structure instead.

All callers of open_cached_file() use mysql_tmpdir as dir. No need to allocate
memory for it since it is constant and available till server shutdown.

This reduces number of allocations from 31 to 27 per OLTP RO transaction.
2014-12-05 11:01:50 +04:00

123 lines
3.3 KiB
C

/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
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; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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,
size_t cache_size, myf cache_myflags)
{
DBUG_ENTER("open_cached_file");
cache->dir= dir;
if (prefix)
{
DBUG_ASSERT(strlen(prefix) == 2);
memcpy(cache->prefix, prefix, 3);
}
else
cache->prefix[0]= 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);
}
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[0] ? cache->prefix : 0,
(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);
}
#endif
}
}
DBUG_VOID_RETURN;
}