ceph/src/boost/libs/log/example/doc/tutorial_fmt_custom.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 <ostream>
   9 #include <fstream>
  10 #include <boost/smart_ptr/shared_ptr.hpp>
  11 #include <boost/smart_ptr/make_shared_object.hpp>
  12 #include <boost/optional.hpp>
  13 #include <boost/log/core.hpp>
  14 #include <boost/log/trivial.hpp>
  15 #include <boost/log/expressions.hpp>
  16 #include <boost/log/sinks/sync_frontend.hpp>
  17 #include <boost/log/sinks/text_ostream_backend.hpp>
  18 #include <boost/log/sources/severity_logger.hpp>
  19 #include <boost/log/sources/record_ostream.hpp>
  20 #include <boost/log/utility/formatting_ostream.hpp>
  21 #include <boost/log/utility/setup/common_attributes.hpp>
  22 #include <boost/log/attributes/value_extraction.hpp>
  23
  24 namespace logging = boost::log;
  25 namespace src = boost::log::sources;
  26 namespace expr = boost::log::expressions;
  27 namespace sinks = boost::log::sinks;
  28
  29 //[ example_tutorial_formatters_custom
  30 void my_formatter(logging::record_view const& rec, logging::formatting_ostream& strm)
  31 {
  32     // Get the LineID attribute value and put it into the stream
  33     strm << logging::extract< unsigned int >("LineID", rec) << ": ";
  34
  35     // The same for the severity level.
  36     // The simplified syntax is possible if attribute keywords are used.
  37     strm << "<" << rec[logging::trivial::severity] << "> ";
  38
  39     // Finally, put the record message to the stream
  40     strm << rec[expr::smessage];
  41 }
  42
  43 void init()
  44 {
  45     typedef sinks::synchronous_sink< sinks::text_ostream_backend > text_sink;
  46     boost::shared_ptr< text_sink > sink = boost::make_shared< text_sink >();
  47
  48     sink->locked_backend()->add_stream(
  49         boost::make_shared< std::ofstream >("sample.log"));
  50
  51     sink->set_formatter(&my_formatter);
  52
  53     logging::core::get()->add_sink(sink);
  54 }
  55 //]
  56
  57 int main(int, char*[])
  58 {
  59     init();
  60     logging::add_common_attributes();
  61
  62     using namespace logging::trivial;
  63     src::severity_logger< severity_level > lg;
  64
  65     BOOST_LOG_SEV(lg, trace) << "A trace severity message";
  66     BOOST_LOG_SEV(lg, debug) << "A debug severity message";
  67     BOOST_LOG_SEV(lg, info) << "An informational severity message";
  68     BOOST_LOG_SEV(lg, warning) << "A warning severity message";
  69     BOOST_LOG_SEV(lg, error) << "An error severity message";
  70     BOOST_LOG_SEV(lg, fatal) << "A fatal severity message";
  71
  72     return 0;
  73 }