libcruft-util/log/log.hpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2012-2019 Danny Robson <danny@nerdcruft.net>
 */

#pragma once

#include "level.hpp"
#include "packet.hpp"
#include "sink/base.hpp"

#include <memory>
#include <string>


namespace cruft::log {
    ///////////////////////////////////////////////////////////////////////////
    sink::base& default_sink (void);
    sink::base& default_sink (std::unique_ptr<sink::base>);


    //-------------------------------------------------------------------------
    void write (level_t, std::string const &msg);
    void write (level_t, char const *msg);
    void write (level_t, std::string_view msg);


    //-------------------------------------------------------------------------
    template <typename FormatT, typename ...ArgsT>
    void
    write (level_t l, FormatT fmt, ArgsT &&...args)
    {
        default_sink ().write (
            packet (
                l,
                std::forward<FormatT> (fmt),
                std::forward<ArgsT> (args)...
            )
        );
    }
}


//-------------------------------------------------------------------------
// Various convenience macros for logging specific strings with a well
// known severity.
//
// The format string _must_ be a compile time literal so that compile time
// checking of strings and arguments is possible.
//
// LOG_DEBUG is treated similarly to assert; if NDEBUG is defined then we
// compile out the statement so as to gain a little runtime efficiency.

#define LOG(LEVEL, FMT, ...)    \
do {                            \
    ::cruft::log::write (       \
        (LEVEL),                \
        FMT_STRING(FMT)         \
        __VA_OPT__(,)           \
        __VA_ARGS__             \
    );                          \
} while (0)

#define LOG_EMERGENCY(FMT, ...) LOG(::cruft::log::EMERGENCY, FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_ALERT(FMT, ...)     LOG(::cruft::log::ALERT,     FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_CRITICAL(FMT, ...)  LOG(::cruft::log::CRITICAL,  FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_ERROR(FMT, ...)     LOG(::cruft::log::ERROR,     FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_WARNING(FMT, ...)   LOG(::cruft::log::WARNING,   FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_NOTICE(FMT, ...)    LOG(::cruft::log::NOTICE,    FMT __VA_OPT__(,) __VA_ARGS__)
#define LOG_INFO(FMT, ...)      LOG(::cruft::log::INFO,      FMT __VA_OPT__(,) __VA_ARGS__)

#if !defined(NDEBUG)
#define LOG_DEBUG(FMT, ...) LOG(::cruft::log::DEBUG, FMT __VA_OPT__(,) __VA_ARGS__)
#else
#define LOG_DEBUG(...) do { ; } while (0)
#endif

#define LOG_WARN(...) LOG_WARNING(__VA_ARGS__)