log.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*
   3  * ALSA SEQ < - > JACK MIDI bridge
   4  *
   5  * Copyright (c) 2008,2009,2010 Nedko Arnaudov <nedko@arnaudov.name>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; version 2 of the License.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  */
  20
  21 #include <stdbool.h>
  22 #include <stdarg.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <stdlib.h>
  27 #include <time.h>
  28 #include <sys/stat.h>
  29
  30 #include "log.h"
  31 #include "paths.h"
  32
  33 static ino_t g_log_file_ino;
  34 static FILE * g_logfile = NULL;
  35
  36 static bool a2j_log_open(void)
  37 {
  38     struct stat st;
  39     int ret;
  40     int retry;
  41
  42     if (g_logfile != NULL)
  43     {
  44         ret = stat(g_a2j_log_path, &st);
  45         if (ret != 0 || g_log_file_ino != st.st_ino)
  46         {
  47             fclose(g_logfile);
  48         }
  49         else
  50         {
  51             return true;
  52         }
  53     }
  54
  55     for (retry = 0; retry < 10; retry++)
  56     {
  57         g_logfile = fopen(g_a2j_log_path, "a");
  58         if (g_logfile == NULL)
  59         {
  60             fprintf(stderr, "Cannot open a2jmidid log file \"%s\": %d (%s)\n", g_a2j_log_path, errno, strerror(errno));
  61             return false;
  62         }
  63
  64         ret = stat(g_a2j_log_path, &st);
  65         if (ret == 0)
  66         {
  67             g_log_file_ino = st.st_ino;
  68             return true;
  69         }
  70
  71         fclose(g_logfile);
  72         g_logfile = NULL;
  73     }
  74
  75     fprintf(stderr, "Cannot stat just opened a2jmidid log file \"%s\": %d (%s). %d retries\n", g_a2j_log_path, errno, strerror(errno), retry);
  76     return false;
  77 }
  78
  79 bool a2j_log_init(bool use_logfile)
  80 {
  81   if (use_logfile)
  82   {
  83     return a2j_log_open();
  84   }
  85
  86   return true;
  87 }
  88
  89 void a2j_log_uninit(void)
  90 {
  91         if (g_logfile != NULL)
  92         {
  93                 fclose(g_logfile);
  94         }
  95 }
  96
  97 void
  98 a2j_log(
  99         unsigned int level,
 100         const char * format,
 101         ...)
 102 {
 103         va_list ap;
 104         FILE * stream;
 105         time_t timestamp;
 106         char timestamp_str[26];
 107
 108         if (g_logfile != NULL && a2j_log_open())
 109         {
 110                 stream = g_logfile;
 111         }
 112         else
 113         {
 114                 switch (level)
 115                 {
 116                 case A2J_LOG_LEVEL_DEBUG:
 117                 case A2J_LOG_LEVEL_INFO:
 118                         stream = stdout;
 119                         break;
 120                 case A2J_LOG_LEVEL_ERROR:
 121                 default:
 122                         stream = stderr;
 123                 }
 124         }
 125
 126         if (g_logfile != NULL)
 127   {
 128     time(&timestamp);
 129     ctime_r(&timestamp, timestamp_str);
 130     timestamp_str[24] = 0;
 131
 132     fprintf(stream, "%s: ", timestamp_str);
 133   }
 134
 135         va_start(ap, format);
 136         vfprintf(stream, format, ap);
 137         fflush(stream);
 138         va_end(ap);
 139 }