Boost.log create text file backend manually - boost-log

Question

Logger.h
enum ChannelType {
main_channel,
sub_channel
};
BOOST_LOG_ATTRIBUTE_KEYWORD(channel, "Channel", ChannelType)
class Logger {
public:
enum severity_level
{
debug,
info,
warning,
error,
fatal
};
static void init(Logger::severity_level level);
typedef boost::log::sources::severity_channel_logger< Logger::severity_level, ChannelType > logger_type;
static thread_local logger_type gl;
static thread_local logger_type motion_checker;
};
Logger.cpp
void Logger::init(Logger::severity_level level)
{
boost::shared_ptr<boost::log::core> core = boost::log::core::get();
core->set_exception_handler(boost::log::make_exception_suppressor());
core->set_filter(boost::log::expressions::attr<Logger::severity_level>("Severity") >= level);
{
typedef boost::log::sinks::asynchronous_sink<boost::log::sinks::text_multifile_backend> multifile_sink;
boost::shared_ptr<multifile_sink> sink(new multifile_sink);
sink->locked_backend()->set_file_name_composer(boost::log::sinks::file::as_file_name_composer(
boost::log::expressions::stream << "./log/Sub/" << boost::log::expressions::attr< std::string >("RoleName") << ".log"));
sink->set_formatter
(
boost::log::expressions::format("[%1%] - %2%")
% boost::log::expressions::attr< boost::posix_time::ptime >("TimeStamp")
% boost::log::expressions::smessage
);
sink->set_filter(channel == sub_channel);
core->add_sink(sink);
}
//============use add_file_log==============
boost::log::add_file_log(
boost::log::keywords::filter = channel == main_channel,
boost::log::keywords::file_name = "./log/%Y%m%d.log",
boost::log::keywords::auto_flush = true,
boost::log::keywords::open_mode = (std::ios::out | std::ios::app),
boost::log::keywords::time_based_rotation = boost::log::sinks::file::rotation_at_time_point(0, 0, 0),
boost::log::keywords::format = "[%TimeStamp%] (%LineID%) {%ThreadID%}: %Message%"
);
//==================use add_file_log end====================
//=========manually add sink, this has problem================
boost::shared_ptr< boost::log::sinks::text_file_backend > backend =
boost::make_shared< boost::log::sinks::text_file_backend >(
boost::log::keywords::filter = channel == main_channel,
boost::log::keywords::file_name = "./log/%Y%m%d.log",
boost::log::keywords::auto_flush = true,
boost::log::keywords::open_mode = (std::ios::out | std::ios::app),
boost::log::keywords::time_based_rotation = boost::log::sinks::file::rotation_at_time_point(0, 0, 0),
boost::log::keywords::format = "[%TimeStamp%] (%LineID%) {%ThreadID%}: %Message%"
);
typedef boost::log::sinks::asynchronous_sink<boost::log::sinks::text_file_backend> file_sink;
boost::shared_ptr< file_sink > sink(new file_sink(backend));
core->add_sink(sink);
//============manually add end==========================
boost::log::add_common_attributes();
}
thread_local Logger::logger_type Logger::gl(boost::log::keywords::channel = main_channel);
thread_local Logger::logger_type Logger::motion_checker(boost::log::keywords::channel = sub_channel);
main.cpp
int main()
{
Logger::init(Logger::debug);
BOOST_LOG_SEV(Logger::gl, Logger::debug) << "ssss";
{
BOOST_LOG_SCOPED_LOGGER_ATTR(Logger::motion_checker, "RoleName", boost::log::attributes::constant< std::string >("aaa"))
BOOST_LOG_SEV(Logger::motion_checker, Logger::debug) << "aaaa";
}
system("pause");
return 0;
}
Using add_file_log, every thing is OK, but the manually add sink lost all attributes, only message in there. And the filter is also not work, sub_channel message will add to this file. The reason I create this file sink manually is because add_file_log create sync sink, I want a async sink.

Answer 1

The problem is that the named parameters format and filter are used by the sink frontend, not the backend, and you pass them to the backend. As a result neither filter nor formatter are set.
I suggest you move all named parameters to the sink frontend constructor and let it pass the parameters to the backend constructor instead of constructing the backend yourself.
typedef boost::log::sinks::asynchronous_sink<boost::log::sinks::text_file_backend> file_sink;
boost::shared_ptr< file_sink > sink = boost::make_shared< file_sink >(
boost::log::keywords::filter = channel == main_channel,
boost::log::keywords::file_name = "./log/%Y%m%d.log",
boost::log::keywords::auto_flush = true,
boost::log::keywords::open_mode = (std::ios::out | std::ios::app),
boost::log::keywords::time_based_rotation = boost::log::sinks::file::rotation_at_time_point(0, 0, 0),
boost::log::keywords::format = "[%TimeStamp%] (%LineID%) {%ThreadID%}: %Message%"
);
core->add_sink(sink);