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 <cstdarg>
  26 #include <cstdio>
  27 #include <fcntl.h>
  28 #include <iostream>
  29 #include <string>
  30 #include <syslog.h>
  31
  32 #define UTIL_MAX_ERROR_SIZE 2048
  33
  34 namespace datadifferential {
  35 namespace util {
  36
  37 /** Verbosity levels.
  38  */
  39 enum verbose_t
  40 {
  41   // Logging this will cause shutdown
  42   VERBOSE_FATAL= LOG_EMERG, // syslog:LOG_EMERG
  43
  44   VERBOSE_ALERT= LOG_ALERT, // syslog:LOG_ALERT
  45   VERBOSE_CRITICAL= LOG_CRIT, //  syslog:LOG_CRIT
  46
  47   VERBOSE_ERROR= LOG_ERR, // syslog:LOG_ERR
  48
  49   VERBOSE_WARN= LOG_WARNING, // syslog:LOG_WARNING
  50
  51   VERBOSE_NOTICE= LOG_NOTICE, // syslog:LOG_NOTICE
  52
  53   VERBOSE_INFO= LOG_INFO, // syslog:LOG_INFO
  54
  55   VERBOSE_DEBUG= LOG_DEBUG // syslog:LOG_DEBUG
  56 };
  57
  58
  59 struct log_info_st
  60 {
  61   std::string name;
  62   std::string filename;
  63   int fd;
  64   bool opt_syslog;
  65   bool opt_file;
  66   bool init_success;
  67
  68   log_info_st(const std::string& name_arg, const std::string &filename_arg, bool syslog_arg) :
  69     name(name_arg),
  70     filename(filename_arg),
  71     fd(-1),
  72     opt_syslog(syslog_arg),
  73     opt_file(false),
  74     init_success(false)
  75   {
  76     if (opt_syslog)
  77     {
  78       openlog(name.c_str(), LOG_PID | LOG_NDELAY, LOG_USER);
  79     }
  80
  81     init();
  82   }
  83
  84   void init()
  85   {
  86     if (filename.size())
  87     {
  88       if (filename.compare("stderr") == 0)
  89       {
  90         fd= STDERR_FILENO;
  91       }
  92       else
  93       {
  94         fd= open(filename.c_str(), O_CREAT | O_WRONLY | O_APPEND, 0644);
  95         if (fd == -1)
  96         {
  97           if (opt_syslog)
  98           {
  99             char buffer[1024];
 100             char *getcwd_ret= getcwd(buffer, sizeof(buffer));
 101             syslog(LOG_ERR, "Could not open log file \"%.*s\", from \"%s\", open failed with (%s)",
 102                    int(filename.size()), filename.c_str(),
 103                    getcwd_ret,
 104                    strerror(errno));
 105           }
 106           std::cerr << "Could not open log file for writing, switching to stderr." << std::endl;
 107
 108           fd= STDERR_FILENO;
 109         }
 110       }
 111
 112       opt_file= true;
 113     }
 114
 115     init_success= true;
 116   }
 117
 118   bool initialized() const
 119   {
 120     return init_success;
 121   }
 122
 123   int file() const
 124   {
 125     return fd;
 126   }
 127
 128   void write(verbose_t verbose, const char *format, ...)
 129   {
 130     if (opt_file or opt_syslog)
 131     {
 132       va_list args;
 133       va_start(args, format);
 134       char mesg[BUFSIZ];
 135       int mesg_length= vsnprintf(mesg, sizeof(mesg), format, args);
 136       va_end(args);
 137
 138       if (opt_file)
 139       {
 140         char buffer[UTIL_MAX_ERROR_SIZE];
 141         int buffer_length= snprintf(buffer, sizeof(buffer), "%7s %.*s\n", verbose_name(verbose), mesg_length, mesg);
 142         if (::write(file(), buffer, buffer_length) == -1)
 143         {
 144           std::cerr << "Could not write to log file." << std::endl;
 145           syslog(LOG_EMERG, "gearmand could not open log file %s, got error %s", filename.c_str(), strerror(errno));
 146         }
 147
 148       }
 149
 150       if (opt_syslog)
 151       {
 152         syslog(int(verbose), "%7s %.*s", verbose_name(verbose), mesg_length, mesg);
 153       }
 154     }
 155   }
 156
 157   ~log_info_st()
 158   {
 159     if (fd != -1 and fd != STDERR_FILENO)
 160     {
 161       close(fd);
 162     }
 163
 164     if (opt_syslog)
 165     {
 166       closelog();
 167     }
 168   }
 169
 170 private:
 171   const char *verbose_name(verbose_t verbose)
 172   {
 173     switch (verbose)
 174     {
 175     case VERBOSE_FATAL:
 176       return "FATAL";
 177
 178     case VERBOSE_ALERT:
 179       return "ALERT";
 180
 181     case VERBOSE_CRITICAL:
 182       return "CRITICAL";
 183
 184     case VERBOSE_ERROR:
 185       return "ERROR";
 186
 187     case VERBOSE_WARN:
 188       return "WARNING";
 189
 190     case VERBOSE_NOTICE:
 191       return "NOTICE";
 192
 193     case VERBOSE_INFO:
 194       return "INFO";
 195
 196     case VERBOSE_DEBUG:
 197       return "DEBUG";
 198
 199     default:
 200       break;
 201     }
 202
 203     return "UNKNOWN";
 204   }
 205 };
 206
 207 } // namespace util
 208 } // namespace datadifferential