add RateLimiter class

include/RateLimiter.h

@@ -0,0 +1,20 @@
+#include "Common.h"
+#include <chrono>
+#include <fstream>
+#include <iostream>
+#include <mutex>
+#include <unordered_map>
+#include <unordered_set>
+
+class RateLimiter {
+public:
+    RateLimiter();
+    bool isConnectionAllowed(const std::string& client_address);
+
+private:
+    std::unordered_map<std::string, std::vector<std::chrono::time_point<std::chrono::high_resolution_clock>>> m_connection;
+    std::mutex m_connection_mutex;
+
+    void blockIP(const std::string& client_address);
+    bool isIPBlocked(const std::string& client_address);
+};