git.m6w6.name Git - m6w6/libmemcached/blob - util/log.hpp

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  libtest
   4  *
   5  *  Copyright (C) 2011-2012 Data Differential, http://datadifferential.com/
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Lesser General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 3 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Lesser General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Lesser General Public
  18  *  License along with this library; if not, write to the Free Software
  19  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  20  */
  21
  22 #pragma once
  23
  24 #include <cerrno>
  25 #include <cstdio>
  26 #include <fcntl.h>
  27 #include <iostream>
  28 #include <string>
  29 #include <syslog.h>
  30
  31 #define UTIL_MAX_ERROR_SIZE 2048
  32
  33 namespace datadifferential {
  34 namespace util {
  35
  36 /** Verbosity levels.
  37  */
  38 enum verbose_t
  39 {
  40   // Logging this will cause shutdown
  41   VERBOSE_FATAL= LOG_EMERG, // syslog:LOG_EMERG
  42
  43   VERBOSE_ALERT= LOG_ALERT, // syslog:LOG_ALERT
  44   VERBOSE_CRITICAL= LOG_CRIT, //  syslog:LOG_CRIT
  45
  46   VERBOSE_ERROR= LOG_ERR, // syslog:LOG_ERR
  47
  48   VERBOSE_WARN= LOG_WARNING, // syslog:LOG_WARNING
  49
  50   VERBOSE_NOTICE= LOG_NOTICE, // syslog:LOG_NOTICE
  51
  52   VERBOSE_INFO= LOG_INFO, // syslog:LOG_INFO
  53
  54   VERBOSE_DEBUG= LOG_DEBUG // syslog:LOG_DEBUG
  55 };
  56
  57
  58 struct log_info_st
  59 {
  60   std::string name;
  61   std::string filename;
  62   int fd;
  63   bool opt_syslog;
  64   bool opt_file;
  65   bool init_success;
  66
  67   log_info_st(const std::string& name_arg, const std::string &filename_arg, bool syslog_arg) :
  68     name(name_arg),
  69     filename(filename_arg),
  70     fd(-1),
  71     opt_syslog(syslog_arg),
  72     opt_file(false),
  73     init_success(false)
  74   {
  75     if (opt_syslog)
  76     {
  77       openlog(name.c_str(), LOG_PID | LOG_NDELAY, LOG_USER);
  78     }
  79
  80     init();
  81   }
  82
  83   void init()
  84   {
  85     if (filename.size())
  86     {
  87       if (filename.compare("stderr") == 0)
  88       {
  89         fd= STDERR_FILENO;
  90       }
  91       else
  92       {
  93         fd= open(filename.c_str(), O_CREAT | O_WRONLY | O_APPEND, 0644);
  94         if (fd == -1)
  95         {
  96           if (opt_syslog)
  97           {
  98             char buffer[1024];
  99             (void)getcwd(buffer, sizeof(buffer));
 100             syslog(LOG_ERR, "Could not open log file \"%.*s\", from \"%s\", open failed with (%s)",
 101                    int(filename.size()), filename.c_str(),
 102                    buffer,
 103                    strerror(errno));
 104           }
 105           std::cerr << "Could not open log file for writing, switching to stderr." << std::endl;
 106
 107           fd= STDERR_FILENO;
 108         }
 109       }
 110
 111       opt_file= true;
 112     }
 113
 114     init_success= true;
 115   }
 116
 117   bool initialized() const
 118   {
 119     return init_success;
 120   }
 121
 122   int file() const
 123   {
 124     return fd;
 125   }
 126
 127   void write(verbose_t verbose, const char *mesg)
 128   {
 129     if (opt_file)
 130     {
 131       char buffer[UTIL_MAX_ERROR_SIZE];
 132       int buffer_length= snprintf(buffer, sizeof(buffer), "%7s %s\n", verbose_name(verbose), mesg);
 133       if (::write(file(), buffer, buffer_length) == -1)
 134       {
 135         std::cerr << "Could not write to log file." << std::endl;
 136         syslog(LOG_EMERG, "gearmand could not open log file %s, got error %s", filename.c_str(), strerror(errno));
 137       }
 138
 139     }
 140
 141     if (opt_syslog)
 142     {
 143       syslog(int(verbose), "%7s %s", verbose_name(verbose), mesg);
 144     }
 145   }
 146
 147   ~log_info_st()
 148   {
 149     if (fd != -1 and fd != STDERR_FILENO)
 150     {
 151       close(fd);
 152     }
 153
 154     if (opt_syslog)
 155     {
 156       closelog();
 157     }
 158   }
 159
 160 private:
 161   const char *verbose_name(verbose_t verbose)
 162   {
 163     switch (verbose)
 164     {
 165     case VERBOSE_FATAL:
 166       return "FATAL";
 167
 168     case VERBOSE_ALERT:
 169       return "ALERT";
 170
 171     case VERBOSE_CRITICAL:
 172       return "CRITICAL";
 173
 174     case VERBOSE_ERROR:
 175       return "ERROR";
 176
 177     case VERBOSE_WARN:
 178       return "WARNING";
 179
 180     case VERBOSE_NOTICE:
 181       return "NOTICE";
 182
 183     case VERBOSE_INFO:
 184       return "INFO";
 185
 186     case VERBOSE_DEBUG:
 187       return "DEBUG";
 188
 189     default:
 190       break;
 191     }
 192
 193     return "UNKNOWN";
 194   }
 195 };
 196
 197 } // namespace util
 198 } // namespace datadifferential