我正在尝试为我的应用程序做一个日志。我想添加一个属性，这样我就可以知道日志属于哪个类。我已经开始测试它是否有效:

#include <boost/log/expressions.hpp>
#include <boost/log/attributes.hpp>
#include <boost/log/common.hpp>
#include <boost/log/sources/severity_logger.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include <boost/log/sinks/syslog_backend.hpp>

enum severity_levels
{
    debug,
    info,
    warning,
    error
};

typedef boost::log::sinks::synchronous_sink< boost::log::sinks::syslog_backend > SinkSysLogBackEnd;
typedef boost::log::sources::severity_logger< severity_levels > BoostLogger;

std::ostream& operator<< (std::ostream& strm, severity_levels level)
{
    static const char* strings[] =
    {
        "debug",
        "info",
        "warning",
        "error"
    };

    if (static_cast< std::size_t >(level) < sizeof(strings) / sizeof(*strings))
        strm << strings[level];
    else
        strm << static_cast< int >(level);

    return strm;
}

BOOST_LOG_ATTRIBUTE_KEYWORD(severity, "Severity", severity_levels)
BOOST_LOG_ATTRIBUTE_KEYWORD(executable, "Executable", std::string)
BOOST_LOG_ATTRIBUTE_KEYWORD(className, "Class name", std::string)

void init_syslog()
{
    // Create a backend
    boost::shared_ptr< SinkSysLogBackEnd > sink(new SinkSysLogBackEnd());

    // We'll have to map our custom levels to the syslog levels
    boost::log::sinks::syslog::custom_severity_mapping< severity_levels > mapping("Severity");
    mapping[info] = boost::log::sinks::syslog::info;
    mapping[warning] = boost::log::sinks::syslog::warning;
    mapping[error] = boost::log::sinks::syslog::error;

    sink->set_formatter(
        boost::log::expressions::stream
        // line id will be written in hex, 8-digits, zero-filled
        << executable << " <" << severity
        << "> : " << boost::log::expressions::smessage);

    sink->locked_backend()->set_severity_mapper(mapping);

    // Set the remote address to sent syslog messages to
    sink->locked_backend()->set_target_address("localhost");

    // Wrap it into the frontend and register in the core.
    // The backend requires synchronization in the frontend.
    boost::log::core::get()->add_sink(sink);
}

class Cls1
{
    BoostLogger m_lg;
public:
    Cls1()
    {
        // set the class name to Cls1
    }

    void foo()
    {
        // print log that has "Class Name" attribute set to "Cls1"
    }
};

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


    void foo()
    {
        // print log that has "Class Name" attribute set to "Cls2"
    }
};

int main(int argc, char** argv)
{
    init_syslog();

    Cls1 o1;
    o1.foo();
    Cls2 o2;
    o2.foo();

    return 0;
}

现在我卡住了...

1. 怎么做比较好？
2. 如何将属性设置为想要的值？
3. 我应该将 BoostLogger 成员设为静态吗？

感谢您的任何建议。我看过 boost 日志属性教程( link1 、 link2 、 link3 )，但我还没有找到有用的东西...

最佳答案

下面是我编写的示例:

记录器.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

记录器.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);
}

主要.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;
}

关于c++ - boost 日志记录类属性，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25041577/