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- /*
- * Copyright Andrey Semashev 2007 - 2015.
- * Distributed under the Boost Software License, Version 1.0.
- * (See accompanying file LICENSE_1_0.txt or copy at
- * http://www.boost.org/LICENSE_1_0.txt)
- */
- #include <cstddef>
- #include <string>
- #include <map>
- #include <iostream>
- #include <fstream>
- #include <boost/smart_ptr/shared_ptr.hpp>
- #include <boost/smart_ptr/make_shared_object.hpp>
- #include <boost/log/sinks.hpp>
- #include <boost/log/expressions.hpp>
- #include <boost/log/attributes/scoped_attribute.hpp>
- #include <boost/log/sources/logger.hpp>
- #include <boost/log/sources/record_ostream.hpp>
- #include <boost/log/utility/value_ref.hpp>
- #include <boost/log/utility/manipulators/add_value.hpp>
- namespace logging = boost::log;
- namespace src = boost::log::sources;
- namespace expr = boost::log::expressions;
- namespace sinks = boost::log::sinks;
- namespace keywords = boost::log::keywords;
- //[ example_expressions_has_attr_stat_accumulator
- // Declare attribute keywords
- BOOST_LOG_ATTRIBUTE_KEYWORD(stat_stream, "StatisticStream", std::string)
- BOOST_LOG_ATTRIBUTE_KEYWORD(change, "Change", int)
- // A simple sink backend to accumulate statistic information
- class my_stat_accumulator :
- public sinks::basic_sink_backend< sinks::synchronized_feeding >
- {
- // A map of accumulated statistic values,
- // ordered by the statistic information stream name
- typedef std::map< std::string, int > stat_info_map;
- stat_info_map m_stat_info;
- public:
- // Destructor
- ~my_stat_accumulator()
- {
- // Display the accumulated data
- stat_info_map::const_iterator it = m_stat_info.begin(), end = m_stat_info.end();
- for (; it != end; ++it)
- {
- std::cout << "Statistic stream: " << it->first
- << ", accumulated value: " << it->second << "\n";
- }
- std::cout.flush();
- }
- // The method is called for every log record being put into the sink backend
- void consume(logging::record_view const& rec)
- {
- // First, acquire statistic information stream name
- logging::value_ref< std::string, tag::stat_stream > name = rec[stat_stream];
- if (name)
- {
- // Next, get the statistic value change
- logging::value_ref< int, tag::change > change_amount = rec[change];
- if (change_amount)
- {
- // Accumulate the statistic data
- m_stat_info[name.get()] += change_amount.get();
- }
- }
- }
- };
- // The function registers two sinks - one for statistic information,
- // and another one for other records
- void init()
- {
- boost::shared_ptr< logging::core > core = logging::core::get();
- // Create a backend and attach a stream to it
- boost::shared_ptr< sinks::text_ostream_backend > backend =
- boost::make_shared< sinks::text_ostream_backend >();
- backend->add_stream(
- boost::shared_ptr< std::ostream >(new std::ofstream("test.log")));
- // Create a frontend and setup filtering
- typedef sinks::synchronous_sink< sinks::text_ostream_backend > log_sink_type;
- boost::shared_ptr< log_sink_type > log_sink(new log_sink_type(backend));
- // All records that don't have a "StatisticStream" attribute attached
- // will go to the "test.log" file
- log_sink->set_filter(!expr::has_attr(stat_stream));
- core->add_sink(log_sink);
- // Create another sink that will receive all statistic data
- typedef sinks::synchronous_sink< my_stat_accumulator > stat_sink_type;
- boost::shared_ptr< stat_sink_type > stat_sink(new stat_sink_type());
- // All records with a "StatisticStream" string attribute attached
- // will go to the my_stat_accumulator sink
- stat_sink->set_filter(expr::has_attr(stat_stream));
- core->add_sink(stat_sink);
- }
- // This simple macro will simplify putting statistic data into a logger
- #define PUT_STAT(lg, stat_stream_name, change)\
- if (true) {\
- BOOST_LOG_SCOPED_LOGGER_TAG(lg, "StatisticStream", stat_stream_name);\
- BOOST_LOG(lg) << logging::add_value("Change", (int)(change));\
- } else ((void)0)
- void logging_function()
- {
- src::logger lg;
- // Put a regular log record, it will go to the "test.log" file
- BOOST_LOG(lg) << "A regular log record";
- // Put some statistic data
- PUT_STAT(lg, "StreamOne", 10);
- PUT_STAT(lg, "StreamTwo", 20);
- PUT_STAT(lg, "StreamOne", -5);
- }
- //]
- int main(int, char*[])
- {
- init();
- logging_function();
- return 0;
- }
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