libs/log/example/doc/sources_net_connection.cpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2014.
   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 <string>
  10 #include <fstream>
  11 #include <boost/smart_ptr/shared_ptr.hpp>
  12 #include <boost/smart_ptr/make_shared_object.hpp>
  13 #include <boost/move/utility.hpp>
  14 #include <boost/log/core.hpp>
  15 #include <boost/log/expressions.hpp>
  16 #include <boost/log/attributes/constant.hpp>
  17 #include <boost/log/attributes/scoped_attribute.hpp>
  18 #include <boost/log/attributes/attribute_value_impl.hpp>
  19 #include <boost/log/sources/logger.hpp>
  20 #include <boost/log/sources/record_ostream.hpp>
  21 #include <boost/log/sinks/sync_frontend.hpp>
  22 #include <boost/log/sinks/text_ostream_backend.hpp>
  23 #include <boost/log/utility/setup/common_attributes.hpp>
  24 #include <boost/log/utility/manipulators/add_value.hpp>
  25
  26 namespace logging = boost::log;
  27 namespace src = boost::log::sources;
  28 namespace expr = boost::log::expressions;
  29 namespace sinks = boost::log::sinks;
  30 namespace attrs = boost::log::attributes;
  31
  32 BOOST_LOG_ATTRIBUTE_KEYWORD(line_id, "LineID", unsigned int)
  33 BOOST_LOG_ATTRIBUTE_KEYWORD(remote_address, "RemoteAddress", std::string)
  34 BOOST_LOG_ATTRIBUTE_KEYWORD(received_size, "ReceivedSize", std::size_t)
  35 BOOST_LOG_ATTRIBUTE_KEYWORD(sent_size, "SentSize", std::size_t)
  36
  37 //[ example_sources_network_connection
  38 class network_connection
  39 {
  40     src::logger m_logger;
  41     logging::attribute_set::iterator m_remote_addr;
  42
  43 public:
  44     void on_connected(std::string const& remote_addr)
  45     {
  46         // Put the remote address into the logger to automatically attach it
  47         // to every log record written through the logger
  48         m_remote_addr = m_logger.add_attribute("RemoteAddress",
  49             attrs::constant< std::string >(remote_addr)).first;
  50
  51         // The straightforward way of logging
  52         if (logging::record rec = m_logger.open_record())
  53         {
  54             rec.attribute_values().insert("Message",
  55                 attrs::make_attribute_value(std::string("Connection established")));
  56             m_logger.push_record(boost::move(rec));
  57         }
  58     }
  59     void on_disconnected()
  60     {
  61         // The simpler way of logging: the above "if" condition is wrapped into a neat macro
  62         BOOST_LOG(m_logger) << "Connection shut down";
  63
  64         // Remove the attribute with the remote address
  65         m_logger.remove_attribute(m_remote_addr);
  66     }
  67     void on_data_received(std::size_t size)
  68     {
  69         // Put the size as an additional attribute
  70         // so it can be collected and accumulated later if needed.
  71         // The attribute will be attached only to this log record.
  72         BOOST_LOG(m_logger) << logging::add_value("ReceivedSize", size) << "Some data received";
  73     }
  74     void on_data_sent(std::size_t size)
  75     {
  76         BOOST_LOG(m_logger) << logging::add_value("SentSize", size) << "Some data sent";
  77     }
  78 };
  79 //]
  80
  81 int main(int, char*[])
  82 {
  83     // Construct the sink
  84     typedef sinks::synchronous_sink< sinks::text_ostream_backend > text_sink;
  85     boost::shared_ptr< text_sink > sink = boost::make_shared< text_sink >();
  86
  87     // Add a stream to write log to
  88     sink->locked_backend()->add_stream(
  89         boost::make_shared< std::ofstream >("sample.log"));
  90
  91     // Set the formatter
  92     sink->set_formatter
  93     (
  94         expr::stream
  95             << line_id
  96             << ": [" << remote_address << "] "
  97             << expr::if_(expr::has_attr(received_size))
  98                [
  99                     expr::stream << "[Received: " << received_size << "] "
 100                ]
 101             << expr::if_(expr::has_attr(sent_size))
 102                [
 103                     expr::stream << "[Sent: " << sent_size << "] "
 104                ]
 105             << expr::smessage
 106     );
 107
 108     // Register the sink in the logging core
 109     logging::core::get()->add_sink(sink);
 110
 111     // Register other common attributes, such as time stamp and record counter
 112     logging::add_common_attributes();
 113
 114     // Emulate network activity
 115     network_connection conn;
 116
 117     conn.on_connected("11.22.33.44");
 118     conn.on_data_received(123);
 119     conn.on_data_sent(321);
 120     conn.on_disconnected();
 121
 122     return 0;
 123 }