src/journal_file.c

   1 /*======================================================================*
   2  * Copyright (C) 2008 Light Weight Event System                         *
   3  * All rights reserved.                                                 *
   4  *                                                                      *
   5  * This program is free software; you can redistribute it and/or modify *
   6  * it under the terms of the GNU General Public License as published by *
   7  * the Free Software Foundation; either version 2 of the License, or    *
   8  * (at your option) any later version.                                  *
   9  *                                                                      *
  10  * This program is distributed in the hope that it will be useful,      *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  13  * GNU General Public License for more details.                         *
  14  *                                                                      *
  15  * You should have received a copy of the GNU General Public License    *
  16  * along with this program; if not, write to the Free Software          *
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                   *
  18  * Boston, MA 02110-1301 USA.                                           *
  19  *======================================================================*/
  20 #include "config.h"
  21
  22 #include "journal.h"
  23 #include "journal_file.h"
  24
  25 #include "rename_journal.h"
  26 #include "log.h"
  27 #include "opt.h"
  28
  29 #include <fcntl.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34
  35 #include <sys/stat.h>
  36 #include <sys/types.h>
  37
  38 #if HAVE_SYS_STATVFS_H
  39 #include <sys/statvfs.h>
  40 #endif
  41
  42 struct priv {
  43   char* path;
  44   FILE* fp;
  45   time_t ot;
  46   long long nbytes_written;
  47 };
  48
  49 static void destructor(struct journal* this_journal)
  50 {
  51   struct priv* ppriv;
  52
  53   this_journal->vtbl->close(this_journal);
  54
  55   ppriv = (struct priv*)this_journal->priv;
  56
  57   free(ppriv->path);
  58   free(ppriv);
  59
  60   this_journal->vtbl = 0;
  61   this_journal->priv = 0;
  62 }
  63
  64 static int xopen(struct journal* this_journal, int flags)
  65 {
  66   struct priv* ppriv = (struct priv*)this_journal->priv;
  67   const char* mode;
  68   struct stat buf;
  69   time_t epoch = 0; /* Crashed files may include data from the past. */
  70
  71   /* If this journal is already open, return an error. */
  72   if ( ppriv->fp )
  73     {
  74       return -1;
  75     }
  76
  77   switch ( flags )
  78     {
  79       case O_RDONLY:
  80         mode = "rb";
  81         break;
  82
  83       case O_WRONLY:
  84         mode = "wb";
  85         if ( 0 == stat(ppriv->path, &buf) )
  86           {
  87             rename_journal(ppriv->path, &epoch);
  88           }
  89         break;
  90
  91       case O_RDWR:
  92         mode = "w+b";
  93         break;
  94
  95       default:
  96         return -1;
  97     }
  98
  99   ppriv->fp = fopen(ppriv->path, mode);
 100
 101   if ( ! ppriv->fp )
 102     {
 103       return -1;
 104     }
 105
 106 #if HAVE_SYS_STATVFS_H
 107   if ( flags == O_WRONLY )
 108     {
 109       struct statvfs stfsbuf;
 110
 111       if ( -1 == statvfs(ppriv->path, &stfsbuf) )
 112         {
 113           LOG_WARN("Unable to determine free space available for %s.\n",
 114                    ppriv->path);
 115         }
 116       else
 117         {
 118           /* Check free space. */
 119           /* tmpfs give f_bsize==0 */
 120           long bsize = (stfsbuf.f_bsize!=0) ? stfsbuf.f_bsize : 4096 ;
 121           long lsz = ppriv->nbytes_written / bsize ;
 122
 123           if ( lsz > (stfsbuf.f_bavail / 2.) )
 124             {
 125               LOG_WARN("Low on disk space for new log %s.\n", ppriv->path);
 126               LOG_WARN("Available space is %d blocks of %d bytes each.\n", stfsbuf.f_bavail, bsize);
 127               LOG_WARN("Last log file contained %lld bytes.\n", ppriv->nbytes_written);
 128             }
 129         }
 130     }
 131 #endif
 132
 133   ppriv->ot = time(NULL);
 134   ppriv->nbytes_written = 0;
 135
 136   return 0;
 137 }
 138
 139 static int xclose(struct journal* this_journal)
 140 {
 141   struct priv* ppriv = (struct priv*)this_journal->priv;
 142
 143   if ( ! ppriv->fp )
 144     {
 145       return -1;
 146     }
 147
 148   if ( fclose(ppriv->fp) )
 149     {
 150       ppriv->fp = 0;
 151       return -1;
 152     }
 153
 154   rename_journal(ppriv->path, &ppriv->ot);
 155   ppriv->fp = 0;
 156   return 0;
 157 }
 158
 159 static int xread(struct journal* this_journal, void* ptr, size_t size)
 160 {
 161   size_t ret = fread(ptr, size, 1, ((struct priv*)this_journal->priv)->fp);
 162   return (int)ret * size;
 163 }
 164
 165 static int xwrite(struct journal* this_journal, void* ptr, size_t size)
 166 {
 167   struct priv* ppriv = (struct priv*)this_journal->priv;
 168
 169   size_t ret = fwrite(ptr, size, 1, ((struct priv*)this_journal->priv)->fp);
 170   ppriv->nbytes_written += ret * size;
 171   return (int)ret * size;
 172 }
 173
 174 int journal_file_ctor(struct journal* this_journal, const char* path)
 175 {
 176   static struct journal_vtbl vtbl = {
 177     destructor,
 178     xopen, xclose,
 179     xread, xwrite
 180   };
 181
 182   struct priv* ppriv;
 183
 184   this_journal->vtbl = 0;
 185   this_journal->priv = 0;
 186
 187   ppriv = (struct priv*)malloc(sizeof(struct priv));
 188   if ( 0 == ppriv )
 189     {
 190       LOG_ER("Failed to allocate %d bytes for journal data.\n",
 191           sizeof(*ppriv));
 192       return -1;
 193     }
 194   memset(ppriv, 0, sizeof(*ppriv));
 195
 196   if ( 0 == (ppriv->path = strdup(path)) )
 197     {
 198       free(ppriv);
 199       return -1;
 200     }
 201
 202   this_journal->vtbl = &vtbl;
 203   this_journal->priv = ppriv;
 204
 205   return 0;
 206 }