Different boost log sinks for every class

问题

I am new to boost log.

My algorithm has 4 main steps and I want the logging for every step in one file. So that I have 4 sinks. My idea is that I can change the sink on every step. Is that possible?

At the moment I have my looger.h with a global logger

#ifndef LOGGER_H_
#define LOGGER_H_

#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
#include <boost/thread/thread.hpp>
#include <boost/log/core.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include <boost/log/sinks/text_ostream_backend.hpp>
#include <boost/log/sources/record_ostream.hpp>
#include <boost/log/support/date_time.hpp>
#include <boost/log/common.hpp>
#include <boost/log/expressions.hpp>
#include <boost/log/attributes.hpp>
#include <boost/log/sinks.hpp>
#include <boost/log/sources/logger.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/utility/setup/formatter_parser.hpp>
#include <boost/log/sources/severity_logger.hpp>
#include <boost/log/sources/severity_feature.hpp>
#include <fstream>

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;

enum sign_severity_level {
  trace,
  debug,
  info,
  warning,
  error,
  fatal,
  report
};

void InitLog()
{
    typedef sinks::synchronous_sink<sinks::text_ostream_backend> TextSink;

    // init sink1
    boost::shared_ptr<sinks::text_ostream_backend> backend1 = boost::make_shared<sinks::text_ostream_backend>();
    backend1->add_stream(boost::shared_ptr<std::ostream>(new std::ofstream("sign.log")));
    backend1->auto_flush(true);
    boost::shared_ptr<TextSink> sink1(new TextSink(backend1));
    sink1->set_formatter(
            expr::format("[%1%]<%2%>(%3%): %4%") % expr::format_date_time < boost::posix_time::ptime
                    > ("TimeStamp", "%Y-%m-%d %H:%M:%S") % expr::attr < sign_severity_level > ("Severity") % expr::attr
                    < attrs::current_thread_id::value_type > ("ThreadID") % expr::smessage);
    sink1->set_filter(expr::attr < sign_severity_level > ("Severity") >= warning);
    logging::core::get()->add_sink(sink1);

    logging::add_common_attributes();
    logging::core::get()->add_global_attribute("ThreadID", attrs::current_thread_id());
}
BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(my_logger, src::severity_logger_mt<sign_severity_level>)


#endif /* LOGGER_H_ */

Is it possible to change the sink after every step?

回答1:

You need to change only stream of a sink:

void set_log_file(const char* filename) {
  backend_->remove_stream(current_stream_);
  current_stream_.reset(new std::ofstream(filename));
  backend_->add_stream(current_stream_);
}

Usage:

manager.set_log_file("log_1.txt");
BOOST_LOG_SEV(log, error) << "This will go to log_1";
BOOST_LOG_SEV(log, error) << "And this one";

manager.set_log_file("log_2.txt");
BOOST_LOG_SEV(log, error) << "This will go to log_2";

manager.set_log_file("log_3.txt");
BOOST_LOG_SEV(log, error) << "This will go to log_3";

Result:

> cat log_1.txt
[...]<4>(0x00007fe742977780): This will go to log_1
[...]<4>(0x00007fe742977780): And this one
> cat log_2.txt
[...]<4>(0x00007fe742977780): This will go to log_2
> cat log_3.txt
[...]<4>(0x00007fe742977780): This will go to log_3

Full example: http://pastebin.com/e3qDQ8tT

来源：https://stackoverflow.com/questions/24037206/different-boost-log-sinks-for-every-class

标签

c++

logging

boost

boost-log