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/* Copyright (C) 2000-2001, 2004-2005 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; 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#include "mysql_priv.h"
#include <sys/stat.h>
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
mapped_files::mapped_files(const char * filename,uchar *magic,uint magic_length)
{
#ifdef HAVE_MMAP
name=my_strdup(filename,MYF(0));
use_count=1;
error=0;
map=0;
size=0;
if ((file=my_open(name,O_RDONLY,MYF(MY_WME))) >= 0)
{
struct stat stat_buf;
if (!fstat(file,&stat_buf))
{
if (!(map=(uchar*) my_mmap(0,(size_t)(size= stat_buf.st_size),PROT_READ,
MAP_SHARED | MAP_NORESERVE,file,
0L)))
{
error=errno;
my_error(ER_NO_FILE_MAPPING, MYF(0), (char *) name, error);
}
}
if (map && memcmp(map,magic,magic_length))
{
my_error(ER_WRONG_MAGIC, MYF(0), name);
(void) my_munmap((char*) map,(size_t)size);
map=0;
}
if (!map)
{
(void) my_close(file,MYF(0));
file= -1;
}
}
#endif
}
mapped_files::~mapped_files()
{
#ifdef HAVE_MMAP
if (file >= 0)
{
(void) my_munmap((char*) map,(size_t)size);
(void) my_close(file,MYF(0));
file= -1; map=0;
}
my_free(name,MYF(0));
#endif
}
static I_List<mapped_files> maps_in_use;
/*
** Check if a file is mapped. If it is, then return pointer to old map,
** else alloc new object
*/
mapped_files *map_file(const char * name,uchar *magic,uint magic_length)
{
#ifdef HAVE_MMAP
pthread_mutex_lock(&LOCK_mapped_file);
I_List_iterator<mapped_files> list(maps_in_use);
mapped_files *map;
char path[FN_REFLEN];
sprintf(path,"%s/%s/%s.uniq",mysql_data_home,current_thd->db,name);
(void) unpack_filename(path,path);
while ((map=list++))
{
if (!strcmp(path,map->name))
break;
}
if (!map)
{
map=new mapped_files(path,magic,magic_length);
maps_in_use.append(map);
}
else
{
map->use_count++;
if (!map->map)
my_error(ER_NO_FILE_MAPPING, MYF(0), path, map->error);
}
pthread_mutex_unlock(&LOCK_mapped_file);
return map;
#else
return NULL;
#endif
}
/*
** free the map if there are no more users for it
*/
void unmap_file(mapped_files *map)
{
#ifdef HAVE_MMAP
pthread_mutex_lock(&LOCK_mapped_file);
if (!map->use_count--)
delete map;
pthread_mutex_unlock(&LOCK_mapped_file);
#endif
}
/*****************************************************************************
** Instansiate templates
*****************************************************************************/
#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
/* Used templates */
template class I_List<mapped_files>;
template class I_List_iterator<mapped_files>;
#endif
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