Add simple message buffer and dispatcher

lib/utils/message-buffer.hpp

@@ -0,0 +1,42 @@
+#pragma once
+#include <deque>
+#include <mutex>
+#include <optional>
+
+namespace advss {
+
+template<class T> class MessageBuffer {
+public:
+	bool Empty();
+	void AppendMessage(const T &);
+	std::optional<T> ConsumeMessage();
+
+private:
+	std::deque<T> _buffer;
+	std::mutex _mutex;
+};
+
+template<class T> inline bool MessageBuffer<T>::Empty()
+{
+	std::lock_guard<std::mutex> lock(_mutex);
+	return _buffer.empty();
+}
+
+template<class T> inline void MessageBuffer<T>::AppendMessage(const T &message)
+{
+	std::lock_guard<std::mutex> lock(_mutex);
+	_buffer.emplace_back(message);
+}
+
+template<class T> inline std::optional<T> MessageBuffer<T>::ConsumeMessage()
+{
+	std::lock_guard<std::mutex> lock(_mutex);
+	if (_buffer.empty()) {
+		return {};
+	}
+	T message = _buffer.at(0);
+	_buffer.pop_front();
+	return message;
+}
+
+} // namespace advss