Integrate heartbeat

DeFi-Data-Engine/DeFi Data Engine/src/main/java/org/out/handler/OutputManager.java

@@ -117,7 +117,6 @@ public final Response send(String tag, String sub_tag, String... data) {
 
 	public final synchronized void add(OutputDestination destination) {
 		destinations.put(destination.getKey(), destination);
-		//destination.send(Packet.packet(handler, "", "", "Connected: " + destination.getKey()));
 	}
 
 	public final synchronized void remove(String key) {

DeFi-Data-Engine/DeFi Data Engine/src/main/java/org/out/socket/SocketManager.java

@@ -24,6 +24,8 @@ public class SocketManager {
 	private static final HashMap<String, DataInputStream> inflow = new HashMap<String, DataInputStream>();
 	private static final HashMap<String, DataOutputStream> outflow = new HashMap<String, DataOutputStream>();
 
+	private static final long HEARTBEAT_OFFSET = 5000L;
+
 	public synchronized static boolean createServer(int port) {
 		if(servers.containsKey(port))
 			return true;
@@ -83,16 +85,38 @@ public void run() {
 						String sub_tag = input[1];
 
 						// retrieve destination
-						String destination = "";
+						String temp_destination = "";
 						for(int i = 0; i < data.length; i++) {
 							if(data[i].equals("destination") && data.length - 1 != i)
-								destination = data[i + 1];
+								temp_destination = data[i + 1];
 						}
 
 						// if no destination found then continue
-						if(destination.equals(""))
+						if(temp_destination.equals(""))
 							continue;
 
+						final String destination = temp_destination;
+
+						// create heartbeat connection
+						Thread heartbeat = new Thread() {
+							public void run() {
+								while(true) {
+									try {
+										Thread.sleep(HEARTBEAT_OFFSET);
+										producer.send("OUT", "EDAT", 
+												"data", "<<<heartbeat>>>",
+												"destination", destination);
+									} catch(Exception e) {
+										Logger.log(String.format("Heartbeat connection terminated for Socket with key <%s>", key));
+										break;
+									}
+								}
+							}
+						};
+
+						// start heartbeat
+						heartbeat.start();
+
 						// execute valid response to engine
 						Response response = producer.send(tag, sub_tag, data);
 
@@ -110,6 +134,11 @@ public void run() {
 								.toString(), 
 								"destination", destination);
 
+						// terminate heartbeat
+						try {
+							heartbeat.interrupt();
+						} catch(Exception e) {}
+
 					} catch(Exception e) {
 						break;
 					}