perf: use Boost.Asio endpoints where is possible

Get rid of extra address construction from strings.

include/ftp/detail/control_connection.hpp

@@ -48,7 +48,7 @@ class control_connection
 
     [[nodiscard]] boost::asio::ip::tcp::endpoint get_local_endpoint() const;
 
-    [[nodiscard]] std::string get_remote_ip() const;
+    [[nodiscard]] boost::asio::ip::tcp::endpoint get_remote_endpoint() const;
 
     void send(std::string_view command);
 

include/ftp/detail/data_connection.hpp

@@ -46,6 +46,8 @@ class data_connection
 
     void open(std::string_view ip, std::uint16_t port);
 
+    void open(const boost::asio::ip::tcp::endpoint & remote_endpoint);
+
     void listen(const boost::asio::ip::tcp::endpoint & endpoint);
 
     void accept();

src/client.cpp

@@ -604,8 +604,11 @@ data_connection_ptr client::process_epsv_command(std::string_view command, repli
                             reply.get_status_string());
     }
 
+    boost::asio::ip::tcp::endpoint remote_endpoint = control_connection_.get_remote_endpoint();
+    boost::asio::ip::tcp::endpoint endpoint(remote_endpoint.address(), remote_port);
+
     data_connection_ptr connection = std::make_unique<data_connection>();
-    connection->open(control_connection_.get_remote_ip(), remote_port);
+    connection->open(endpoint);
 
     reply = process_command(command, replies);
 

src/control_connection.cpp

@@ -123,25 +123,18 @@ boost::asio::ip::tcp::endpoint control_connection::get_local_endpoint() const
     return local_endpoint;
 }
 
-std::string control_connection::get_remote_ip() const
+boost::asio::ip::tcp::endpoint control_connection::get_remote_endpoint() const
 {
     boost::system::error_code ec;
 
     boost::asio::ip::tcp::endpoint remote_endpoint = socket_.remote_endpoint(ec);
 
     if (ec)
     {
-        throw ftp_exception(ec, "Cannot get IP address");
+        throw ftp_exception(ec, "Cannot get remote endpoint");
     }
 
-    std::string ip = remote_endpoint.address().to_string(ec);
-
-    if (ec)
-    {
-        throw ftp_exception(ec, "Cannot get IP address");
-    }
-
-    return ip;
+    return remote_endpoint;
 }
 
 reply control_connection::recv()

src/data_connection.cpp

@@ -67,6 +67,27 @@ void data_connection::open(std::string_view ip, std::uint16_t port)
     }
 }
 
+void data_connection::open(const boost::asio::ip::tcp::endpoint & remote_endpoint)
+{
+    boost::system::error_code ec;
+
+    socket_.connect(remote_endpoint, ec);
+
+    if (ec)
+    {
+        boost::system::error_code ignored;
+
+        /* If the connect fails, and the socket was automatically opened,
+         * the socket is not returned to the closed state.
+         *
+         * https://www.boost.org/doc/libs/1_70_0/doc/html/boost_asio/reference/basic_stream_socket/connect/overload2.html
+         */
+        socket_.close(ignored);
+
+        throw ftp_exception(ec, "Cannot open data connection");
+    }
+}
+
 void data_connection::listen(const boost::asio::ip::tcp::endpoint & endpoint)
 {
     boost::system::error_code ec;