Logger.h

#pragma once
 
/* <editor-fold desc="MIT License">
 
Copyright(c) 2022 Robert Osfield
 
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
</editor-fold> */
 
#include <vsg/core/Inherit.h>
#include <vsg/io/stream.h>
 
#include <mutex>
#include <string_view>
#include <thread>
 
namespace vsg
{
 
    class VSG_DECLSPEC Logger : public Object
    {
    public:
        Logger();
 
        Logger(const Logger& rhs);
 
        enum Level
        {
            LOGGER_ALL = 0,
            LOGGER_DEBUG = 1,
            LOGGER_INFO = 2,
            LOGGER_WARN = 3,
            LOGGER_ERROR = 4,
            LOGGER_FATAL = 5,
            LOGGER_OFF = 6
        };
 
        Level level = LOGGER_INFO;
 
        static ref_ptr<Logger>& instance();
 
        virtual void flush() {}
 
        inline void debug(char* message) { debug(std::string_view(message)); }
        inline void debug(const char* message) { debug(std::string_view(message)); }
        inline void debug(std::string& message) { debug(std::string_view(message)); }
        inline void debug(const std::string& message) { debug(std::string_view(message)); }
 
        void debug(const std::string_view& str)
        {
            if (level > LOGGER_DEBUG) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            debug_implementation(str);
        }
 
        template<typename... Args>
        void debug(Args&&... args)
        {
            if (level > LOGGER_DEBUG) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            debug_implementation(_stream.str());
        }
 
        inline void info(char* message) { info(std::string_view(message)); }
        inline void info(const char* message) { info(std::string_view(message)); }
        inline void info(std::string& message) { info(std::string_view(message)); }
        inline void info(const std::string& message) { info(std::string_view(message)); }
 
        void info(const std::string_view& str)
        {
            if (level > LOGGER_INFO) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            info_implementation(str);
        }
 
        template<typename... Args>
        void info(Args&&... args)
        {
            if (level > LOGGER_INFO) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            info_implementation(_stream.str());
        }
 
        inline void warn(char* message) { warn(std::string_view(message)); }
        inline void warn(const char* message) { warn(std::string_view(message)); }
        inline void warn(std::string& message) { warn(std::string_view(message)); }
        inline void warn(const std::string& message) { warn(std::string_view(message)); }
 
        void warn(const std::string_view& str)
        {
            if (level > LOGGER_WARN) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            warn_implementation(str);
        }
 
        template<typename... Args>
        void warn(Args&&... args)
        {
            if (level > LOGGER_WARN) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            warn_implementation(_stream.str());
        }
 
        inline void error(char* message) { error(std::string_view(message)); }
        inline void error(const char* message) { error(std::string_view(message)); }
        inline void error(std::string& message) { error(std::string_view(message)); }
        inline void error(const std::string& message) { error(std::string_view(message)); }
 
        void error(const std::string_view& str)
        {
            if (level > LOGGER_DEBUG) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            error_implementation(str);
        }
 
        template<typename... Args>
        void error(Args&&... args)
        {
            if (level > LOGGER_ERROR) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            error_implementation(_stream.str());
        }
 
        inline void fatal(char* message) { fatal(std::string_view(message)); }
        inline void fatal(const char* message) { fatal(std::string_view(message)); }
        inline void fatal(std::string& message) { fatal(std::string_view(message)); }
        inline void fatal(const std::string& message) { fatal(std::string_view(message)); }
 
        void fatal(const std::string_view& str)
        {
            if (level > LOGGER_DEBUG) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            fatal_implementation(str);
        }
 
        template<typename... Args>
        void fatal(Args&&... args)
        {
            if (level > LOGGER_ERROR) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            fatal_implementation(_stream.str());
        }
 
        using PrintToStreamFunction = std::function<void(std::ostream&)>;
 
        void debug_stream(PrintToStreamFunction print);
 
        void info_stream(PrintToStreamFunction print);
 
        void warn_stream(PrintToStreamFunction print);
 
        void error_stream(PrintToStreamFunction print);
 
        void fatal_stream(PrintToStreamFunction print);
 
        inline void log(Level msg_level, char* message) { log(msg_level, std::string_view(message)); }
        inline void log(Level msg_level, const char* message) { log(msg_level, std::string_view(message)); }
        inline void log(Level msg_level, std::string& message) { log(msg_level, std::string_view(message)); }
        inline void log(Level msg_level, const std::string& message) { log(msg_level, std::string_view(message)); }
 
        void log(Level msg_level, const std::string_view& message);
 
        template<typename... Args>
        void log(Level msg_level, Args... args)
        {
            if (level > msg_level) return;
 
            std::scoped_lock<std::mutex> lock(_mutex);
            _stream.str({});
            _stream.clear();
            (_stream << ... << args);
 
            switch (msg_level)
            {
            case (LOGGER_DEBUG): debug_implementation(_stream.str()); break;
            case (LOGGER_INFO): info_implementation(_stream.str()); break;
            case (LOGGER_WARN): warn_implementation(_stream.str()); break;
            case (LOGGER_ERROR): error_implementation(_stream.str()); break;
            case (LOGGER_FATAL): fatal_implementation(_stream.str()); break;
            default: break;
            }
        }
 
        void log_stream(Level msg_level, PrintToStreamFunction print);
 
    protected:
        virtual ~Logger();
 
        std::mutex _mutex;
        std::ostringstream _stream;
 
        virtual void debug_implementation(const std::string_view& message) = 0;
        virtual void info_implementation(const std::string_view& message) = 0;
        virtual void warn_implementation(const std::string_view& message) = 0;
        virtual void error_implementation(const std::string_view& message) = 0;
        virtual void fatal_implementation(const std::string_view& message) = 0;
    };
    VSG_type_name(vsg::Logger);
 
    template<typename... Args>
    void debug(Args&&... args)
    {
        Logger::instance()->debug(args...);
    }
 
    inline void debug_stream(Logger::PrintToStreamFunction print)
    {
        Logger::instance()->debug_stream(print);
    }
 
    template<typename... Args>
    void info(Args&&... args)
    {
        Logger::instance()->info(args...);
    }
 
    inline void info_stream(Logger::PrintToStreamFunction print)
    {
        Logger::instance()->info_stream(print);
    }
 
    template<typename... Args>
    void warn(Args&&... args)
    {
        Logger::instance()->warn(args...);
    }
 
    inline void warn_stream(Logger::PrintToStreamFunction print)
    {
        Logger::instance()->warn_stream(print);
    }
 
    template<typename... Args>
    void error(Args&&... args)
    {
        Logger::instance()->error(args...);
    }
 
    inline void error_stream(Logger::PrintToStreamFunction print)
    {
        Logger::instance()->error_stream(print);
    }
 
    template<typename... Args>
    void fatal(Args&&... args)
    {
        Logger::instance()->fatal(args...);
    }
 
    inline void fatal_stream(Logger::PrintToStreamFunction print)
    {
        Logger::instance()->fatal_stream(print);
    }
 
    template<typename... Args>
    void log(Logger::Level msg_level, Args&&... args)
    {
        Logger::instance()->log(msg_level, args...);
    }
 
    inline void log_stream(Logger::Level msg_level, Logger::PrintToStreamFunction print)
    {
        Logger::instance()->log_stream(msg_level, print);
    }
 
    class VSG_DECLSPEC StdLogger : public Inherit<Logger, StdLogger>
    {
    public:
        StdLogger();
 
        std::string debugPrefix = "debug: ";
        std::string infoPrefix = "info: ";
        std::string warnPrefix = "Warning: ";
        std::string errorPrefix = "ERROR: ";
        std::string fatalPrefix = "FATAL: ";
 
        void flush() override;
 
    protected:
        void debug_implementation(const std::string_view& message) override;
        void info_implementation(const std::string_view& message) override;
        void warn_implementation(const std::string_view& message) override;
        void error_implementation(const std::string_view& message) override;
        void fatal_implementation(const std::string_view& message) override;
    };
    VSG_type_name(vsg::StdLogger);
 
    class VSG_DECLSPEC ThreadLogger : public vsg::Inherit<vsg::Logger, ThreadLogger>
    {
    public:
        ThreadLogger();
 
        void setThreadPrefix(std::thread::id id, const std::string& str);
 
        std::string debugPrefix = "debug: ";
        std::string infoPrefix = "info: ";
        std::string warnPrefix = "Warning: ";
        std::string errorPrefix = "ERROR: ";
        std::string fatalPrefix = "FATAL: ";
 
        void flush() override;
 
    protected:
        void print_id(std::ostream& out, std::thread::id id);
 
        void debug_implementation(const std::string_view& message) override;
        void info_implementation(const std::string_view& message) override;
        void warn_implementation(const std::string_view& message) override;
        void error_implementation(const std::string_view& message) override;
        void fatal_implementation(const std::string_view& message) override;
 
        std::map<std::thread::id, std::string> _threadPrefixes;
    };
    VSG_type_name(vsg::ThreadLogger);
 
    class VSG_DECLSPEC NullLogger : public Inherit<Logger, NullLogger>
    {
    public:
        NullLogger();
 
    protected:
        void debug_implementation(const std::string_view&) override;
        void info_implementation(const std::string_view&) override;
        void warn_implementation(const std::string_view&) override;
        void error_implementation(const std::string_view&) override;
        void fatal_implementation(const std::string_view&) override;
    };
    VSG_type_name(vsg::NullLogger);
 
} // namespace vsg