add dummy control session for websockets

server/control_session.hpp

@@ -0,0 +1,78 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2019  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef CONTROL_SESSION_H
+#define CONTROL_SESSION_H
+
+#include "common/queue.h"
+#include "message/message.h"
+#include <asio.hpp>
+#include <atomic>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <set>
+#include <string>
+#include <thread>
+
+
+using asio::ip::tcp;
+
+
+class ControlSession;
+
+
+/// Interface: callback for a received message.
+class ControlMessageReceiver
+{
+public:
+    virtual void onMessageReceived(ControlSession* connection, const std::string& message) = 0;
+};
+
+
+/// Endpoint for a connected control client.
+/**
+ * Endpoint for a connected control client.
+ * Messages are sent to the client with the "send" method.
+ * Received messages from the client are passed to the ControlMessageReceiver callback
+ */
+class ControlSession : public std::enable_shared_from_this<ControlSession>
+{
+public:
+    /// ctor. Received message from the client are passed to MessageReceiver
+    ControlSession(ControlMessageReceiver* receiver, tcp::socket&& socket) : message_receiver_(receiver), socket_(std::move(socket))
+    {
+    }
+    virtual ~ControlSession() = default;
+    virtual void start() = 0;
+    virtual void stop() = 0;
+
+    /// Sends a message to the client (synchronous)
+    virtual bool send(const std::string& message) = 0;
+
+    /// Sends a message to the client (asynchronous)
+    virtual void sendAsync(const std::string& message) = 0;
+
+protected:
+    tcp::socket socket_;
+    ControlMessageReceiver* message_receiver_;
+};
+
+
+
+#endif