提升set_filter不起作用

Boost set_filter is not working

本文关键字：不起作用 filter set 提升      更新时间：2023-10-16

我正在学习Boost。 在教程之后，我尝试通过发送对方法的引用来设置接收器上的筛选器 onlyWarnings。

短：

sink->set_filter(&onlyWarnings);

仅在警告中：

set["Severity"].extract<int>()  // is always 0

我显然在我的代码和教程的重要组成部分中缺少一些东西。

页眉：

#ifndef ONEPRINT_LOGGER_H
#define ONEPRINT_LOGGER_H
#include <boost/log/core/core.hpp>
#include <boost/log/attributes/attribute_value_set.hpp>
#include <boost/log/trivial.hpp>
#include <boost/log/sources/severity_logger.hpp>
#include <boost/log/utility/setup/file.hpp>
#include <boost/log/utility/setup/console.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/sinks.hpp>
#include <boost/core/null_deleter.hpp>
#include <iostream>
namespace expr = boost::log::expressions;
namespace sources = boost::log::sources;
namespace sinks = boost::log::sinks;
namespace keywords = boost::log::keywords;
namespace ids {
    enum severity_level
    {
        normal,
        warning,
        error,
        critical
    };
    class Logger {
    public:
        Logger();
        ~Logger();
        void logIt(std::string msg);
    protected:
        typedef sinks::asynchronous_sink<sinks::text_ostream_backend> asynchronousSink;
        void setupLogging();
    };
}
#endif //ONEPRINT_LOGGER_H

.CPP：

#include "Logger.h"
class counter;
using namespace ids;
namespace {  // NON-MEMBER METHODS
    bool onlyWarnings(const boost::log::attribute_value_set& set)
    {
        return set["Severity"].extract<int>() > 0;
    }
    void severity_and_message(const boost::log::record_view &view, boost::log::formatting_ostream &os)
    {
        os << view.attribute_values()["Severity"].extract<int>() << ": " <<
        view.attribute_values()["Message"].extract<std::string>();
    }
}
Logger::Logger() {
    setupLogging();
    logIt("Testing");
}
Logger::~Logger() {
}
void Logger::setupLogging()
{
    boost::shared_ptr< boost::log::core > core = boost::log::core::get();
    boost::shared_ptr<sinks::text_ostream_backend> backend = boost::make_shared<sinks::text_ostream_backend>();
    boost::shared_ptr<Logger::asynchronousSink> sink(new Logger::asynchronousSink(backend));
    boost::shared_ptr<std::ostream> stream{&std::clog, boost::null_deleter{}};
    sink->locked_backend()->add_stream(stream);
    sink->set_filter(&onlyWarnings);
    sink->set_formatter(&severity_and_message);
    core->add_sink(sink);
}
void Logger::logIt(std::string msg) {
    BOOST_LOG_TRIVIAL(warning) << msg;
    sources::severity_logger<severity_level> severityLogger;
    BOOST_LOG_SEV(severityLogger, critical) << msg;
}

你确定严重性只是另一个属性吗？我建议您从一个工作示例开始，例如：

http://www.boost.org/doc/libs/1_56_0/libs/log/doc/html/log/tutorial/advanced_filtering.html

http://boost-log.sourceforge.net/libs/log/example/doc/tutorial_filtering.cpp

在你开始自己的编码之前，你让他们工作了吗？标记严重性记录器有一个示例筛选器，看起来与您的筛选器非常不同。

bool my_filter(logging::value_ref< severity_level, tag::severity > const& level,
               logging::value_ref< std::string, tag::tag_attr > const& tag)
{
    return level >= warning || tag == "IMPORTANT_MESSAGE";
}

也许尝试更像这样的东西：

bool my_filter(logging::value_ref< severity_level, tag::severity > const& level)
{
    return level >= warning ;
}
相关文章：