libs/log/example/event_log/main.cpp
/*
* 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)
*/
/*!
* \file main.cpp
* \author Andrey Semashev
* \date 16.11.2008
*
* \brief An example of logging into Windows event log.
*
* The example shows the basic usage of the Windows NT event log backend.
* The code defines custom severity levels, initializes the sink and a couple of
* attributes to test with, and writes several records at different levels.
* As a result the written records should appear in the Application log, and
* should be displayed correctly with the Windows event log viewer.
*/
#include <stdexcept>
#include <string>
#include <iostream>
#include <boost/smart_ptr/shared_ptr.hpp>
#include <boost/date_time/posix_time/posix_time_types.hpp>
#include <boost/log/common.hpp>
#include <boost/log/attributes.hpp>
#include <boost/log/expressions.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include <boost/log/sinks/event_log_backend.hpp>
#if !defined(WIN32_LEAN_AND_MEAN)
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include "event_log_messages.h"
namespace logging = boost::log;
namespace attrs = boost::log::attributes;
namespace src = boost::log::sources;
namespace sinks = boost::log::sinks;
namespace expr = boost::log::expressions;
namespace keywords = boost::log::keywords;
//[ example_sinks_event_log_severity
// Define application-specific severity levels
enum severity_level
{
normal,
warning,
error
};
//]
void init_logging()
{
//[ example_sinks_event_log_create_backend
// Create an event log sink
boost::shared_ptr< sinks::event_log_backend > backend(
new sinks::event_log_backend((
keywords::message_file = "%SystemDir%\\event_log_messages.dll",
keywords::log_name = "My Application",
keywords::log_source = "My Source"
))
);
//]
//[ example_sinks_event_log_event_composer
// Create an event composer. It is initialized with the event identifier mapping.
sinks::event_log::event_composer composer(
sinks::event_log::direct_event_id_mapping< int >("EventID"));
// For each event described in the message file, set up the insertion string formatters
composer[LOW_DISK_SPACE_MSG]
// the first placeholder in the message
// will be replaced with contents of the "Drive" attribute
% expr::attr< std::string >("Drive")
// the second placeholder in the message
// will be replaced with contents of the "Size" attribute
% expr::attr< boost::uintmax_t >("Size");
composer[DEVICE_INACCESSIBLE_MSG]
% expr::attr< std::string >("Drive");
composer[SUCCEEDED_MSG]
% expr::attr< unsigned int >("Duration");
// Then put the composer to the backend
backend->set_event_composer(composer);
//]
//[ example_sinks_event_log_mappings
// We'll have to map our custom levels to the event log event types
sinks::event_log::custom_event_type_mapping< severity_level > type_mapping("Severity");
type_mapping[normal] = sinks::event_log::make_event_type(MY_SEVERITY_INFO);
type_mapping[warning] = sinks::event_log::make_event_type(MY_SEVERITY_WARNING);
type_mapping[error] = sinks::event_log::make_event_type(MY_SEVERITY_ERROR);
backend->set_event_type_mapper(type_mapping);
// Same for event categories.
// Usually event categories can be restored by the event identifier.
sinks::event_log::custom_event_category_mapping< int > cat_mapping("EventID");
cat_mapping[LOW_DISK_SPACE_MSG] = sinks::event_log::make_event_category(MY_CATEGORY_1);
cat_mapping[DEVICE_INACCESSIBLE_MSG] = sinks::event_log::make_event_category(MY_CATEGORY_2);
cat_mapping[SUCCEEDED_MSG] = sinks::event_log::make_event_category(MY_CATEGORY_3);
backend->set_event_category_mapper(cat_mapping);
//]
//[ example_sinks_event_log_register_sink
// Create the frontend for the sink
boost::shared_ptr< sinks::synchronous_sink< sinks::event_log_backend > > sink(
new sinks::synchronous_sink< sinks::event_log_backend >(backend));
// Set up filter to pass only records that have the necessary attribute
sink->set_filter(expr::has_attr< int >("EventID"));
logging::core::get()->add_sink(sink);
//]
}
//[ example_sinks_event_log_facilities
BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(event_logger, src::severity_logger_mt< severity_level >)
// The function raises an event of the disk space depletion
void announce_low_disk_space(std::string const& drive, boost::uintmax_t size)
{
BOOST_LOG_SCOPED_THREAD_TAG("EventID", (int)LOW_DISK_SPACE_MSG);
BOOST_LOG_SCOPED_THREAD_TAG("Drive", drive);
BOOST_LOG_SCOPED_THREAD_TAG("Size", size);
// Since this record may get accepted by other sinks,
// this message is not completely useless
BOOST_LOG_SEV(event_logger::get(), warning) << "Low disk " << drive
<< " space, " << size << " Mb is recommended";
}
// The function raises an event of inaccessible disk drive
void announce_device_inaccessible(std::string const& drive)
{
BOOST_LOG_SCOPED_THREAD_TAG("EventID", (int)DEVICE_INACCESSIBLE_MSG);
BOOST_LOG_SCOPED_THREAD_TAG("Drive", drive);
BOOST_LOG_SEV(event_logger::get(), error) << "Cannot access drive " << drive;
}
// The structure is an activity guard that will emit an event upon the activity completion
struct activity_guard
{
activity_guard()
{
// Add a stop watch attribute to measure the activity duration
m_it = event_logger::get().add_attribute("Duration", attrs::timer()).first;
}
~activity_guard()
{
BOOST_LOG_SCOPED_THREAD_TAG("EventID", (int)SUCCEEDED_MSG);
BOOST_LOG_SEV(event_logger::get(), normal) << "Activity ended";
event_logger::get().remove_attribute(m_it);
}
private:
logging::attribute_set::iterator m_it;
};
//]
int main(int argc, char* argv[])
{
try
{
// Initialize the library
init_logging();
// Make some events
{
activity_guard activity;
announce_low_disk_space("C:", 2 * 1024 * 1024);
announce_device_inaccessible("D:");
}
return 0;
}
catch (std::exception& e)
{
std::cout << "FAILURE: " << e.what() << std::endl;
return 1;
}
}