release/src/router/mysql/mysys/mf_cache.c

   1 /* Copyright (c) 2000, 2001, 2007 MySQL AB
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 of the License.
   6
   7    This program is distributed in the hope that it will be useful,
   8    but WITHOUT ANY WARRANTY; without even the implied warranty of
   9    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10    GNU General Public License for more details.
  11
  12    You should have received a copy of the GNU General Public License
  13    along with this program; if not, write to the Free Software
  14    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  15
  16 /* Open a temporary file and cache it with io_cache. Delete it on close */
  17
  18 #include "mysys_priv.h"
  19 #include <m_string.h>
  20 #include "my_static.h"
  21 #include "mysys_err.h"
  22
  23         /*
  24           Remove an open tempfile so that it doesn't survive
  25           if we crash;  If the operating system doesn't support
  26           this, just remember the file name for later removal
  27         */
  28
  29 static my_bool cache_remove_open_tmp(IO_CACHE *cache __attribute__((unused)),
  30                                      const char *name)
  31 {
  32 #if O_TEMPORARY == 0
  33 #if !defined(CANT_DELETE_OPEN_FILES)
  34   /* The following should always succeed */
  35   (void) my_delete(name,MYF(MY_WME | ME_NOINPUT));
  36 #else
  37   int length;
  38   if (!(cache->file_name=
  39         (char*) my_malloc((length=strlen(name)+1),MYF(MY_WME))))
  40   {
  41     my_close(cache->file,MYF(0));
  42     cache->file = -1;
  43     errno=my_errno=ENOMEM;
  44     return 1;
  45   }
  46   memcpy(cache->file_name,name,length);
  47 #endif
  48 #endif /* O_TEMPORARY == 0 */
  49   return 0;
  50 }
  51
  52         /*
  53         ** Open tempfile cached by IO_CACHE
  54         ** Should be used when no seeks are done (only reinit_io_buff)
  55         ** Return 0 if cache is inited ok
  56         ** The actual file is created when the IO_CACHE buffer gets filled
  57         ** If dir is not given, use TMPDIR.
  58         */
  59
  60 my_bool open_cached_file(IO_CACHE *cache, const char* dir, const char *prefix,
  61                          size_t cache_size, myf cache_myflags)
  62 {
  63   DBUG_ENTER("open_cached_file");
  64   cache->dir=    dir ? my_strdup(dir,MYF(cache_myflags & MY_WME)) : (char*) 0;
  65   cache->prefix= (prefix ? my_strdup(prefix,MYF(cache_myflags & MY_WME)) :
  66                  (char*) 0);
  67   cache->file_name=0;
  68   cache->buffer=0;                              /* Mark that not open */
  69   if (!init_io_cache(cache,-1,cache_size,WRITE_CACHE,0L,0,
  70                      MYF(cache_myflags | MY_NABP)))
  71   {
  72     DBUG_RETURN(0);
  73   }
  74   my_free(cache->dir,   MYF(MY_ALLOW_ZERO_PTR));
  75   my_free(cache->prefix,MYF(MY_ALLOW_ZERO_PTR));
  76   DBUG_RETURN(1);
  77 }
  78
  79         /* Create the temporary file */
  80
  81 my_bool real_open_cached_file(IO_CACHE *cache)
  82 {
  83   char name_buff[FN_REFLEN];
  84   int error=1;
  85   DBUG_ENTER("real_open_cached_file");
  86   if ((cache->file=create_temp_file(name_buff, cache->dir, cache->prefix,
  87                                     (O_RDWR | O_BINARY | O_TRUNC |
  88                                      O_TEMPORARY | O_SHORT_LIVED),
  89                                     MYF(MY_WME))) >= 0)
  90   {
  91     error=0;
  92     cache_remove_open_tmp(cache, name_buff);
  93   }
  94   DBUG_RETURN(error);
  95 }
  96
  97
  98 void close_cached_file(IO_CACHE *cache)
  99 {
 100   DBUG_ENTER("close_cached_file");
 101   if (my_b_inited(cache))
 102   {
 103     File file=cache->file;
 104     cache->file= -1;                            /* Don't flush data */
 105     (void) end_io_cache(cache);
 106     if (file >= 0)
 107     {
 108       (void) my_close(file,MYF(0));
 109 #ifdef CANT_DELETE_OPEN_FILES
 110       if (cache->file_name)
 111       {
 112         (void) my_delete(cache->file_name,MYF(MY_WME | ME_NOINPUT));
 113         my_free(cache->file_name,MYF(0));
 114       }
 115 #endif
 116     }
 117     my_free(cache->dir,MYF(MY_ALLOW_ZERO_PTR));
 118     my_free(cache->prefix,MYF(MY_ALLOW_ZERO_PTR));
 119   }
 120   DBUG_VOID_RETURN;
 121 }