ceph/src/boost/libs/log/example/doc/extension_app_launcher.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 <cstdlib>
   9 #include <string>
  10 #include <utility>
  11 #include <stdexcept>
  12 #include <boost/smart_ptr/shared_ptr.hpp>
  13 #include <boost/phoenix.hpp>
  14 #include <boost/log/trivial.hpp>
  15 #include <boost/log/core.hpp>
  16 #include <boost/log/expressions.hpp>
  17 #include <boost/log/attributes/current_process_name.hpp>
  18 #include <boost/log/sinks/sync_frontend.hpp>
  19 #include <boost/log/sinks/basic_sink_backend.hpp>
  20 #include <boost/log/sources/record_ostream.hpp>
  21 #include <boost/log/utility/value_ref.hpp>
  22 #include <boost/log/utility/formatting_ostream.hpp>
  23 #include <boost/log/utility/manipulators/add_value.hpp>
  24
  25 namespace logging = boost::log;
  26 namespace attrs = boost::log::attributes;
  27 namespace src = boost::log::sources;
  28 namespace expr = boost::log::expressions;
  29 namespace sinks = boost::log::sinks;
  30 namespace keywords = boost::log::keywords;
  31
  32 //[ example_extension_app_launcher_definition
  33 // The backend starts an external application to display notifications
  34 class app_launcher :
  35     public sinks::basic_formatted_sink_backend<
  36         char,                                                                   /*< target character type >*/
  37         sinks::synchronized_feeding                                             /*< in order not to spawn too many application instances we require records to be processed serial >*/
  38     >
  39 {
  40 public:
  41     // The function consumes the log records that come from the frontend
  42     void consume(logging::record_view const& rec, string_type const& command_line);
  43 };
  44 //]
  45
  46 //[ example_extension_app_launcher_consume
  47 // The function consumes the log records that come from the frontend
  48 void app_launcher::consume(logging::record_view const& rec, string_type const& command_line)
  49 {
  50     std::system(command_line.c_str());
  51 }
  52 //]
  53
  54 //[ example_extension_app_launcher_formatting
  55 BOOST_LOG_ATTRIBUTE_KEYWORD(process_name, "ProcessName", std::string)
  56 BOOST_LOG_ATTRIBUTE_KEYWORD(caption, "Caption", std::string)
  57
  58 // Custom severity level formatting function
  59 std::string severity_level_as_urgency(
  60     logging::value_ref< logging::trivial::severity_level, logging::trivial::tag::severity > const& level)
  61 {
  62     if (!level || level.get() == logging::trivial::info)
  63         return "normal";
  64     logging::trivial::severity_level lvl = level.get();
  65     if (lvl < logging::trivial::info)
  66         return "low";
  67     else
  68         return "critical";
  69 }
  70
  71 // The function initializes the logging library
  72 void init_logging()
  73 {
  74     boost::shared_ptr< logging::core > core = logging::core::get();
  75
  76     typedef sinks::synchronous_sink< app_launcher > sink_t;
  77     boost::shared_ptr< sink_t > sink(new sink_t());
  78
  79     const std::pair< const char*, const char* > shell_decorations[] =
  80     {
  81         std::pair< const char*, const char* >("\"", "\\\""),
  82         std::pair< const char*, const char* >("$", "\\$"),
  83         std::pair< const char*, const char* >("!", "\\!")
  84     };
  85
  86     // Make the formatter generate the command line for notify-send
  87     sink->set_formatter
  88     (
  89         expr::stream << "notify-send -t 2000 -u "
  90             << boost::phoenix::bind(&severity_level_as_urgency, logging::trivial::severity.or_none())
  91             << expr::if_(expr::has_attr(process_name))
  92                [
  93                     expr::stream << " -a '" << process_name << "'"
  94                ]
  95             << expr::if_(expr::has_attr(caption))
  96                [
  97                     expr::stream << " \"" << expr::char_decor(shell_decorations)[ expr::stream << caption ] << "\""
  98                ]
  99             << " \"" << expr::char_decor(shell_decorations)[ expr::stream << expr::message ] << "\""
 100     );
 101
 102     core->add_sink(sink);
 103
 104     // Add attributes that we will use
 105     core->add_global_attribute("ProcessName", attrs::current_process_name());
 106 }
 107 //]
 108
 109 //[ example_extension_app_launcher_logging
 110 void test_notifications()
 111 {
 112     BOOST_LOG_TRIVIAL(debug) << "Hello, it's a simple notification";
 113     BOOST_LOG_TRIVIAL(info) << logging::add_value(caption, "Caption text") << "And this notification has caption as well";
 114 }
 115 //]
 116
 117 int main(int, char*[])
 118 {
 119     init_logging();
 120     test_notifications();
 121
 122     return 0;
 123 }