Add automatic ping on websockets

source/vibe/http/server.d

@@ -522,11 +522,19 @@ final class HTTPServerSettings {
 	*/
 	bool useCompressionIfPossible = false;
 
+
+	/** Interval between WebSocket ping frames.
+
+		The default value is 60 seconds; set to Duration.zero to disable pings.
+	*/
+	Duration webSocketPingInterval;// = dur!"seconds"(60);
+
 	this()
 	{
 		// need to use the contructor because the Ubuntu 13.10 GDC cannot CTFE dur()
 		maxRequestTime = 0.seconds;
 		keepAliveTimeout = 10.seconds;
+		webSocketPingInterval = 60.seconds;
 	}
 }
 
@@ -692,6 +700,14 @@ final class HTTPServerRequest : HTTPRequest {
 		Session session;
 	}
 
+	package {
+		/** The settings of the server serving this request.
+		 */
+		@property const(HTTPServerSettings) serverSettings() const
+		{
+			return m_settings;
+		}
+	}
 
 	this(SysTime time, ushort port)
 	{

source/vibe/http/websockets.d

@@ -193,6 +193,10 @@ final class WebSocket {
 		Task m_reader;
 		TaskMutex m_readMutex, m_writeMutex;
 		TaskCondition m_readCondition;
+		Timer m_pingTimer;
+		uint m_lastPingIndex;
+		bool m_pongReceived;
+		bool m_pongSkipped;
 	}
 
 	this(ConnectionStream conn, in HTTPServerRequest request)
@@ -204,6 +208,10 @@ final class WebSocket {
 		m_writeMutex = new TaskMutex;
 		m_readMutex = new TaskMutex;
 		m_readCondition = new TaskCondition(m_readMutex);
+		if (request !is null && request.serverSettings.webSocketPingInterval != Duration.zero) {
+			m_pingTimer = setTimer(request.serverSettings.webSocketPingInterval, &sendPing, true);
+			m_pongReceived = true;
+		}
 	}
 
 	/**
@@ -310,7 +318,7 @@ final class WebSocket {
 				frame.writeFrame(m_conn);
 			}
 		}
-
+		if (m_pingTimer) m_pingTimer.stop();
 		if (Task.getThis() != m_reader) m_reader.join();
 	}
 
@@ -367,7 +375,24 @@ final class WebSocket {
 		try {
 			while (!m_conn.empty) {
 				assert(!m_nextMessage);
+				if (m_pingTimer) {
+					if (m_pongSkipped) {
+						logDebug("Pong not received, closing connection");
+						synchronized(m_writeMutex) {
+							m_conn.close();
+						}
+						return;
+					}
+					if (!m_conn.waitForData(request.serverSettings.webSocketPingInterval))
+						continue;
+				}
 				scope msg = new IncomingWebSocketMessage(m_conn);
+				if (msg.frameOpcode == FrameOpcode.pong) {
+					enforce(msg.peek().length == uint.sizeof, "Pong payload has wrong length");
+					enforce(m_lastPingIndex == littleEndianToNative!uint(msg.peek()[0..uint.sizeof]), "Pong payload has wrong value");
+					m_pongReceived = true;
+					continue;
+				}
 				if(msg.frameOpcode == FrameOpcode.close) {
 					logDebug("Got closing frame (%s)", m_sentCloseFrame);
 					if(!m_sentCloseFrame) close();
@@ -387,8 +412,26 @@ final class WebSocket {
 		}
 		m_conn.close();
 	}
-}
 
+	private void sendPing() {
+		if (!m_pongReceived) {
+			logDebug("Pong skipped");
+			m_pongSkipped = true;
+			m_pingTimer.stop();
+			return;
+		}
+		synchronized(m_writeMutex) {
+			m_pongReceived = false;
+			Frame ping;
+			ping.opcode = FrameOpcode.ping;
+			ping.fin = true;
+			ping.payload = nativeToLittleEndian(++m_lastPingIndex);
+
+			ping.writeFrame(m_conn);
+			logDebug("Ping sent");
+		}
+	}
+}
 
 /**
 	Represents a single outgoing _WebSocket message as an OutputStream.
@@ -500,6 +543,7 @@ final class IncomingWebSocketMessage : InputStream {
 				case FrameOpcode.text:
 				case FrameOpcode.binary:
 				case FrameOpcode.close:
+				case FrameOpcode.pong:
 					m_currentFrame = frame;
 					break;
 				case FrameOpcode.ping: