ceph/src/boost/libs/log/example/doc/expressions_channel_severity_filter.cpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2015.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7
   8 #include <cstddef>
   9 #include <iostream>
  10 #include <boost/log/expressions.hpp>
  11 #include <boost/log/sources/severity_channel_logger.hpp>
  12 #include <boost/log/sources/record_ostream.hpp>
  13 #include <boost/log/utility/setup/console.hpp>
  14 #include <boost/log/utility/setup/common_attributes.hpp>
  15
  16 namespace logging = boost::log;
  17 namespace src = boost::log::sources;
  18 namespace expr = boost::log::expressions;
  19 namespace keywords = boost::log::keywords;
  20
  21 //[ example_expressions_channel_severity_filter
  22 // We define our own severity levels
  23 enum severity_level
  24 {
  25     normal,
  26     notification,
  27     warning,
  28     error,
  29     critical
  30 };
  31
  32 // Define the attribute keywords
  33 BOOST_LOG_ATTRIBUTE_KEYWORD(line_id, "LineID", unsigned int)
  34 BOOST_LOG_ATTRIBUTE_KEYWORD(severity, "Severity", severity_level)
  35 BOOST_LOG_ATTRIBUTE_KEYWORD(channel, "Channel", std::string)
  36
  37 //<-
  38 std::ostream& operator<< (std::ostream& strm, severity_level level)
  39 {
  40     static const char* strings[] =
  41     {
  42         "normal",
  43         "notification",
  44         "warning",
  45         "error",
  46         "critical"
  47     };
  48
  49     if (static_cast< std::size_t >(level) < sizeof(strings) / sizeof(*strings))
  50         strm << strings[level];
  51     else
  52         strm << static_cast< int >(level);
  53
  54     return strm;
  55 }
  56 //->
  57
  58 void init()
  59 {
  60     // Create a minimal severity table filter
  61     typedef expr::channel_severity_filter_actor< std::string, severity_level > min_severity_filter;
  62     min_severity_filter min_severity = expr::channel_severity_filter(channel, severity);
  63
  64     // Set up the minimum severity levels for different channels
  65     min_severity["general"] = notification;
  66     min_severity["network"] = warning;
  67     min_severity["gui"] = error;
  68
  69     logging::add_console_log
  70     (
  71         std::clog,
  72         keywords::filter = min_severity || severity >= critical,
  73         keywords::format =
  74         (
  75             expr::stream
  76                 << line_id
  77                 << ": <" << severity
  78                 << "> [" << channel << "] "
  79                 << expr::smessage
  80         )
  81     );
  82 }
  83
  84 // Define our logger type
  85 typedef src::severity_channel_logger< severity_level, std::string > logger_type;
  86
  87 void test_logging(logger_type& lg, std::string const& channel_name)
  88 {
  89     BOOST_LOG_CHANNEL_SEV(lg, channel_name, normal) << "A normal severity level message";
  90     BOOST_LOG_CHANNEL_SEV(lg, channel_name, notification) << "A notification severity level message";
  91     BOOST_LOG_CHANNEL_SEV(lg, channel_name, warning) << "A warning severity level message";
  92     BOOST_LOG_CHANNEL_SEV(lg, channel_name, error) << "An error severity level message";
  93     BOOST_LOG_CHANNEL_SEV(lg, channel_name, critical) << "A critical severity level message";
  94 }
  95 //]
  96
  97 int main(int, char*[])
  98 {
  99     init();
 100     logging::add_common_attributes();
 101
 102     logger_type lg;
 103     test_logging(lg, "general");
 104     test_logging(lg, "network");
 105     test_logging(lg, "gui");
 106     test_logging(lg, "filesystem");
 107
 108     return 0;
 109 }