Add on_write_progress

src/connection_handler.hpp

@@ -35,11 +35,17 @@ public:
    * - If ownership is taken, handler must call Server::releaseBackToServer()
    * when done
    * @note `data` is *not* owned by the connection arena, and its lifetime ends
-   * after the call to process_data.
+   * after the call to on_data_arrived.
    * @note May be called from an arbitrary network thread.
    */
-  virtual void process_data(std::string_view data,
-                            std::unique_ptr<Connection> &conn_ptr) = 0;
+  virtual void on_data_arrived(std::string_view data,
+                               std::unique_ptr<Connection> &conn_ptr) = 0;
+
+  /**
+   * Successfully wrote data on the connection.
+   * @note May be called from an arbitrary network thread.
+   */
+  virtual void on_write_progress(std::unique_ptr<Connection> &) {}
 
   /**
    * Called when a new connection is established.