.

src/featherlog/log_formatter.hpp

@@ -0,0 +1,15 @@
+#ifndef FEATHERLOG_LOG_FORMATTER_HPP
+#define FEATHERLOG_LOG_FORMATTER_HPP
+#include <string>
+
+namespace flog
+{
+    class LogFormatter
+    {
+    public:
+        virtual ~LogFormatter() = default;
+        virtual std::string format() = 0;
+    };
+}
+
+#endif

src/featherlog/log_level.hpp

@@ -0,0 +1,21 @@
+#ifndef FEATHERLOG_LOG_LEVEL_HPP
+#define FEATHERLOG_LOG_LEVEL_HPP
+
+#include <cstdint>
+
+namespace flog
+{
+    enum class LogLevel : uint8_t
+    {
+        TRACE = 0,
+        DEBUG = 1,
+        INFO = 2,
+        WARN = 3,
+        ERROR = 4,
+        FATAL = 5,
+
+	OFF = 0xff,
+    };
+}
+
+#endif

src/featherlog/log_manager.cpp

@@ -0,0 +1,103 @@
+#include "log_manager.hpp"
+
+namespace flog
+{
+
+
+    inline std::shared_ptr<LogManager> LogManager::create()
+    {
+        // ReSharper disable once CppDFAMemoryLeak
+        return std::shared_ptr<LogManager>(new LogManager());
+    }
+
+    inline LogManager::~LogManager()
+    {
+        {
+            std::lock_guard lock(m_loggersMutex);
+            m_loggers.clear();
+        }
+        {
+            std::lock_guard lock(m_logOutputtersMutex);
+            m_logOutputters.clear();
+        }
+    }
+
+    inline LogLevel LogManager::get_min_log_level() const noexcept
+    {
+        return m_minLogLevel.load(std::memory_order_relaxed);
+    }
+
+    inline void LogManager::set_min_log_level(const LogLevel level) noexcept
+    {
+        m_minLogLevel.store(level, std::memory_order_relaxed);
+    }
+
+    inline void LogManager::add_outputter(std::unique_ptr<LogOutputter> outputter)
+    {
+        std::lock_guard lock(m_logOutputtersMutex);
+        m_logOutputters.push_back(std::move(outputter));
+    }
+
+    inline std::shared_ptr<Logger> LogManager::get_logger(const std::string& name)
+    {
+        std::lock_guard lock(m_loggersMutex);
+        if (const auto it = m_loggers.find(name); it != m_loggers.end())
+        {
+            return it->second;
+        }
+
+        const auto logger = std::shared_ptr<Logger>(new Logger(name, weak_from_this()));
+        m_loggers.emplace(name, logger);
+        return logger;
+    }
+
+    inline size_t LogManager::clean_unused_loggers()
+    {
+        std::lock_guard lock(m_loggersMutex);
+        size_t count = 0;
+        for (auto it = m_loggers.begin(); it != m_loggers.end();)
+        {
+            if (it->second.use_count() == 1)
+            {
+                it = m_loggers.erase(it);
+                count += 1;
+            }
+            else
+            {
+                ++it;
+            }
+        }
+        return count;
+    }
+
+    inline void LogManager::print_log(const LogMessage& message) const
+    {
+        std::shared_lock lock(m_logOutputtersMutex);
+        for (auto& outputter : m_logOutputters)
+        {
+            outputter->write(message);
+        }
+    }
+
+    inline LoggerCallback::LoggerCallback(const std::weak_ptr<LogManager>& logManager) noexcept : m_logManager(
+        logManager)
+    {
+    }
+
+    inline void LoggerCallback::print_log(const LogMessage& message) const
+    {
+        if (const auto mgr = m_logManager.lock())
+        {
+            mgr->print_log(message);
+        }
+    }
+
+    inline LogLevel LoggerCallback::get_min_log_level() const noexcept
+    {
+        if (const auto mgr = m_logManager.lock())
+        {
+            return mgr->get_min_log_level();
+        }
+        return LogLevel::OFF;
+    }
+}

src/featherlog/log_manager.hpp

@@ -0,0 +1,59 @@
+#ifndef FEATHERLOG_LOG_MANAGER_HPP
+#define FEATHERLOG_LOG_MANAGER_HPP
+
+#include <atomic>
+#include <memory>
+#include <mutex>
+#include <shared_mutex>
+#include <unordered_map>
+#include <vector>
+
+#include "logger.hpp"
+#include "log_formatter.hpp"
+#include "log_level.hpp"
+#include "log_message.hpp"
+#include "log_outputter.hpp"
+
+namespace flog
+{
+    class LogManager;
+
+    class LogManager : public std::enable_shared_from_this<LogManager>
+    {
+        friend class LoggerCallback;
+
+    public:
+        LogManager(const LogManager&) = delete;
+        LogManager& operator=(const LogManager&) = delete;
+        LogManager(LogManager&&) = delete;
+        LogManager& operator=(LogManager&&) = delete;
+
+        static std::shared_ptr<LogManager> create();
+
+        ~LogManager();
+
+        LogLevel get_min_log_level() const noexcept;
+        void set_min_log_level(LogLevel level) noexcept;
+
+        void add_outputter(std::unique_ptr<LogOutputter> outputter);
+
+        std::shared_ptr<Logger> get_logger(const std::string& name);
+
+        size_t clean_unused_loggers();
+
+    private:
+        LogManager() noexcept = default;
+
+        void print_log(const LogMessage& message) const;
+
+        std::atomic<LogLevel> m_minLogLevel{LogLevel::DEBUG};
+
+        mutable std::shared_mutex m_logOutputtersMutex;
+        std::vector<std::unique_ptr<LogOutputter>> m_logOutputters;
+
+        mutable std::mutex m_loggersMutex;
+        std::unordered_map<std::string, std::shared_ptr<Logger>> m_loggers;
+    };
+}
+
+#endif

src/featherlog/log_message.hpp

@@ -0,0 +1,20 @@
+#ifndef FEATHERLOG_LOG_MESSAGE_HPP
+#define FEATHERLOG_LOG_MESSAGE_HPP
+
+
+#include <chrono>
+#include <string_view>
+
+#include "log_level.hpp"
+
+namespace flog
+{
+    struct LogMessage {
+        std::chrono::system_clock::time_point timestamp;
+        LogLevel level;
+        std::string_view logger_name;
+        std::string text;
+    };
+}
+
+#endif

src/featherlog/log_outputter.hpp

@@ -0,0 +1,27 @@
+#ifndef FEATHERLOG_LOG_OUTPUTER_HPP
+#define FEATHERLOG_LOG_OUTPUTER_HPP
+
+#include <memory>
+#include <string>
+
+#include "log_formatter.hpp"
+#include "log_message.hpp"
+
+namespace flog
+{
+    class LogOutputter
+    {
+    public:
+        virtual ~LogOutputter() = default;
+
+        std::unique_ptr<LogFormatter> set_formatter(const std::unique_ptr<LogFormatter>& formatter);
+        std::unique_ptr<LogFormatter>& get_formatter();
+
+        virtual void write(const LogMessage& message) = 0;
+
+    protected:
+        std::unique_ptr<LogFormatter> m_logFormatter;
+    };
+}
+
+#endif

src/featherlog/logger.hpp

@@ -0,0 +1,33 @@
+#ifndef FEATHERLOG_LOGGER_HPP
+#define FEATHERLOG_LOGGER_HPP
+
+#include <format>
+#include <source_location>
+
+#include "log_manager.hpp"
+
+namespace flog
+{
+    class LoggerCallback;
+
+    class Logger
+    {
+        friend class LogManager;
+
+    public:
+        ~Logger() = default;
+
+        template <typename... Args>
+        void info(std::format_string<Args...> fmt, Args&&... args,
+                  std::source_location loc = std::source_location::current());
+
+    private:
+        Logger(const std::string& name, std::weak_ptr<LogManager> manager) : m_name(name), m_logManager(manager)
+        {  }
+
+        std::string m_name;
+        std::weak_ptr<LogManager> m_logManager;
+    };
+}
+
+#endif