提升日志记录类属性

下面是我编程的示例：

Logger.hpp:

#ifndef LOGGER_HPP
#define LOGGER_HPP
#include <ostream>
#include <fstream>
#include <boost/shared_ptr.hpp>
#include <boost/log/common.hpp>
#include <boost/log/expressions.hpp>
#include <boost/log/attributes.hpp>
#include <boost/log/sources/logger.hpp>
#include <boost/log/sinks/async_frontend.hpp>
#include <boost/log/sinks/text_ostream_backend.hpp>
#include <boost/utility/empty_deleter.hpp>
class Logger
{
public:
    typedef boost::log::sinks::asynchronous_sink<boost::log::sinks::text_ostream_backend> text_sink;
    Logger();
    ~Logger();
    void    Initialize();
    void    Finalize();
    void    addStream(boost::shared_ptr<std::ostream>& stream);
    template< typename T >
    Logger& operator<<(const T& value)
    {
        BOOST_LOG(my_logger::get()) << value;
        return *this;
    }
    typedef Logger& (*LoggerManipulator)(Logger&);
    Logger& operator<<(LoggerManipulator manip)
    {
        return manip(*this);
    }
    static Logger& endl(Logger& stream)
    {
        std::cout << std::endl;
        return stream;
    }

    typedef std::basic_ostream<char, std::char_traits<char>> CoutType;
    typedef CoutType& (*StandardEndLine)(CoutType&);
    Logger& operator<<(StandardEndLine manip)
    {
        manip(std::cout);
        return *this;
    }
private:
    boost::log::sources::logger_mt m_lg;
    boost::shared_ptr<text_sink> m_sink;
};
#endif LOGGER_HPP

Logger.cpp:

    #include <boost/date_time/posix_time/posix_time.hpp>
    #include "Logger.hpp"
    Logger::Logger()
        :
        m_sink(new text_sink),
        m_lg()
    {
    }
    Logger::~Logger()
    {
    }
    void    Logger::Initialize()
    {
        m_sink->locked_backend()->auto_flush(true);
    m_sink->set_formatter
        (
        boost::log::expressions::format("[%1%] - %2%")
        % boost::log::expressions::attr< boost::posix_time::ptime >("TimeStamp")
        % boost::log::expressions::smessage
        );
    boost::log::core::get()->add_sink(m_sink);
    boost::log::core::get()->add_global_attribute("TimeStamp",boost::log::attributes::local_clock());
}
void    Logger::Finalize()
{
}
void    Logger::addStream(boost::shared_ptr<std::ostream>& stream)
{
    m_sink->locked_backend()->add_stream(stream);
}

main.cpp:

int main
{
    boost::shared_ptr<std::ostream> stream_out(&std::clog, boost::empty_deleter());
    boost::shared_ptr<std::ostream> stream_file(new std::ofstream(ProgramName + ".log", std::ostream::app));
    Logger logger;
    logger.addStream(stream_out);
    logger.addStream(stream_file);
    logger.Initialize();
    logger << "Sample";
return 0;
}

我已经为每个类使用静态记录器并使用初始化它们的方法解决了这个问题。类似这样的东西：

BoostLogger setClassNameAttribute(const std::string& classNameIn)
{
    BoostLogger lg;
    lg.add_attribute("ClassName", boost::log::attributes::constant<std::string>(classNameIn));
    return lg;
}

class Cls1
{
    static BoostLogger sm_lg;
public:
    Cls1()
    {
        // set the class name to Cls1
    }
    void foo()
    {
        // print log that has "Class Name" attribute set to "Cls1"
    }
};
BoostLogger Cls1::sm_lg = setClassNameAttribute("Cls1");

class Cls2
{
    static BoostLogger sm_lg;
public:
    Cls2()
    {
        // set the class name to Cls2
    }

    void foo()
    {
        // print log that has "Class Name" attribute set to "Cls2"
    }
};
BoostLogger Cls2::sm_lg = setClassNameAttribute("Cls2");

我已经改编了关于属性和格式的文档中的代码，以实现对此的解决方案。我从我的程序中提取了所有相关的比特来创建下面的示例代码；它不编译，但应该给你一个明确的指示做什么

粗略解释：

• 在格式化程序中的某个位置使用expressions::attr<string>("ClassName")
• 为每个类创建一个类型为severity_logger<severity_level>的静态记录器
• 使用EFraim描述的技术(或其他技术(创建一个静态初始值设定项，该技术将类名属性添加到记录器中，如下所示：logger.add_attribute("ClassName", attrs::constant<string>("Foo"));
• 像这样使用记录器：BOOST_LOG_SEV(logger, trace) << "Hello there";

我省略了很多includes和using namespace的内容——如果找不到内容的来源，请告诉我。

// I have this in my stdafx.h for convenience
typedef boost::log::sources::severity_logger<boost::log::trivial::severity_level> Logger;
// foo.h
class Foo
{
    private:
        static Logger logger;
        static class _Init
        {
        public:
            _Init()
            {
                logger.add_attribute("ClassName", boost::log::attributes::constant<std::string>("Foo"));
            }
        } _initializer;
    public:
        Foo();
}
// foo.cpp
Logger Foo::logger;                     // initialize the static variables
Foo::_Init Foo::_initializer;
Foo::Foo()
{
    BOOST_LOG_SEV(logger, trace) << "Hello there";
}

// main.cpp
int main(int argc, char *argv[])
{
    using namespace boost::log;
    // Set up our sink and formatting
    boost::log::add_file_log(
        boost::log::keywords::file_name = "MyApp_%3N.log",
        boost::log::keywords::rotation_size = 1 * 1024 * 1024,
        boost::log::keywords::max_size = 20 * 1024 * 1024,
        boost::log::keywords::time_based_rotation = boost::log::sinks::file::rotation_at_time_point(0, 0, 0),
        boost::log::keywords::format = 
        (
            expressions::stream 
            << expressions::format_date_time<boost::posix_time::ptime>("TimeStamp", "%Y-%m-%d %H:%M:%S,%f") << "|"
            << expressions::attr<std::string>("ClassName") << "|"
            << trivial::severity << "|"
            << expressions::message 
        ),
        boost::log::keywords::auto_flush = true
        );
    boost::log::add_common_attributes();
    boost::log::core::get()->set_filter(
        boost::log::trivial::severity >= boost::log::trivial::trace
        );
    Foo* foo = new Foo();
}

输出看起来像

2014-08-26 19:16:19006726|Foo|trace|Hello there

(我这样格式化它是因为我使用的日志查看器喜欢这样(

现在，您应该能够按类名对日志消息进行排序。：(