logger.h

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//
// Copyright(c) 2015-2108 Gabi Melman.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
//

#pragma once

// Thread safe logger (except for set_pattern(..), set_formatter(..) and
// set_error_handler())
// Has name, log level, vector of std::shared sink pointers and formatter
// Upon each log write the logger:
// 1. Checks if its log level is enough to log the message and if yes:
// 2. Call the underlying sinks to do the job.
// 3. Each sink use its own private copy of a formatter to format the message
// and send to its destination.
//
// The use of private formatter per sink provides the opportunity to cache some
// formatted data,
// and support customize format per each sink.

#include "spdlog/common.h"
#include "spdlog/formatter.h"
#include "spdlog/sinks/sink.h"

#include <memory>
#include <string>
#include <vector>

namespace spdlog {

class logger
{
public:
    logger(std::string name, sink_ptr single_sink);
    logger(std::string name, sinks_init_list sinks);

    template<typename It>
    logger(std::string name, It begin, It end);

    virtual ~logger();

    logger(const logger &) = delete;
    logger &operator=(const logger &) = delete;

    template<typename... Args>
    void log(level::level_enum lvl, const char *fmt, const Args &... args);

    template<typename... Args>
    void log(source_loc loc, level::level_enum lvl, const char *fmt, const Args &... args);

    void log(level::level_enum lvl, const char *msg);

    void log(source_loc loc, level::level_enum lvl, const char *msg);

    template<typename... Args>
    void trace(const char *fmt, const Args &... args);

    template<typename... Args>
    void debug(const char *fmt, const Args &... args);

    template<typename... Args>
    void info(const char *fmt, const Args &... args);

    template<typename... Args>
    void warn(const char *fmt, const Args &... args);

    template<typename... Args>
    void error(const char *fmt, const Args &... args);

    template<typename... Args>
    void critical(const char *fmt, const Args &... args);

#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
#ifndef _WIN32
#error SPDLOG_WCHAR_TO_UTF8_SUPPORT only supported on windows
#else
    template<typename... Args>
    void log(level::level_enum lvl, const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void log(source_loc source, level::level_enum lvl, const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void trace(const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void debug(const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void info(const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void warn(const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void error(const wchar_t *fmt, const Args &... args);

    template<typename... Args>
    void critical(const wchar_t *fmt, const Args &... args);
#endif // _WIN32
#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT

    // T can be statically converted to string_view
    template<class T, typename std::enable_if<std::is_convertible<T, spdlog::string_view_t>::value, T>::type * = nullptr>
    void log(level::level_enum lvl, const T &);

    // T can be statically converted to string_view
    template<class T, typename std::enable_if<std::is_convertible<T, spdlog::string_view_t>::value, T>::type * = nullptr>
    void log(source_loc loc, level::level_enum lvl, const T &);

    // T cannot be statically converted to string_view
    template<class T, typename std::enable_if<!std::is_convertible<T, spdlog::string_view_t>::value, T>::type * = nullptr>
    void log(level::level_enum lvl, const T &);

    // T cannot be statically converted to string_view
    template<class T, typename std::enable_if<!std::is_convertible<T, spdlog::string_view_t>::value, T>::type * = nullptr>
    void log(source_loc loc, level::level_enum lvl, const T &);

    template<typename T>
    void trace(const T &msg);

    template<typename T>
    void debug(const T &msg);

    template<typename T>
    void info(const T &msg);

    template<typename T>
    void warn(const T &msg);

    template<typename T>
    void error(const T &msg);

    template<typename T>
    void critical(const T &msg);

    bool should_log(level::level_enum msg_level) const;
    void set_level(level::level_enum log_level);

    static level::level_enum default_level();
    level::level_enum level() const;
    const std::string &name() const;

    // set formatting for the sinks in this logger.
    // each sink will get a seperate instance of the formatter object.
    void set_formatter(std::unique_ptr<formatter> formatter);
    void set_pattern(std::string pattern, pattern_time_type time_type = pattern_time_type::local);

    // flush functions
    void flush();
    void flush_on(level::level_enum log_level);
    level::level_enum flush_level() const;

    // sinks
    const std::vector<sink_ptr> &sinks() const;
    std::vector<sink_ptr> &sinks();

    // error handler
    void set_error_handler(log_err_handler err_handler);
    log_err_handler error_handler() const;

    // create new logger with same sinks and configuration.
    virtual std::shared_ptr<logger> clone(std::string logger_name);

protected:
    virtual void sink_it_(details::log_msg &msg);
    virtual void flush_();

    bool should_flush_(const details::log_msg &msg);

    // default error handler.
    // print the error to stderr with the max rate of 1 message/minute.
    void default_err_handler_(const std::string &msg);

    // increment the message count (only if defined(SPDLOG_ENABLE_MESSAGE_COUNTER))
    void incr_msg_counter_(details::log_msg &msg);

    const std::string name_;
    std::vector<sink_ptr> sinks_;
    spdlog::level_t level_{spdlog::logger::default_level()};
    spdlog::level_t flush_level_{level::off};
    log_err_handler err_handler_{[this](const std::string &msg) { this->default_err_handler_(msg); }};
    std::atomic<time_t> last_err_time_{0};
    std::atomic<size_t> msg_counter_{1};
};
} // namespace spdlog

#include "details/logger_impl.h"