fix

src/connection_pool.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <queue>
+#include <memory>
+#include <mutex>
+#include <condition_variable>
+#include "database.h"
+
+class ConnectionPool {
+public:
+    ConnectionPool(const std::string &host, const std::string &port,
+                   const std::string &name, const std::string &user,
+                   const std::string &password, int pool_size);
+
+    std::shared_ptr<Database> getConnection();
+    void releaseConnection(std::shared_ptr<Database> conn);
+
+private:
+    std::queue<std::shared_ptr<Database>> pool;
+    std::mutex pool_mutex;
+    std::condition_variable pool_cv;
+
+    std::string host;
+    std::string port;
+    std::string name;
+    std::string user;
+    std::string password;
+
+    void createPool(int pool_size);
+    void refreshConnection(std::shared_ptr<Database> &conn);
+};