Add RATIO REQUEST/RESPONSES handling in tracker

To do: UPDATE RATIO

src/tracker/TrackerManagement.java

@@ -15,6 +15,8 @@ import protocolP2P.FileList;
 import protocolP2P.Unregister;
 import protocolP2P.Register;
 import protocolP2P.RequestResponseCode;
+import protocolP2P.RatioRequest;
+import protocolP2P.RatioResponse;
 import localException.InternalError;
 import remoteException.EmptyDirectory;
 import exception.LocalException;
@@ -30,6 +32,8 @@ public abstract class TrackerManagement extends ServeErrors implements Runnable
 	protected HostItem tracker;
 	protected Logger logger;
 	protected List<HostItem> hostList = new ArrayList<>();
+	protected Map<HostItem, Long> ratioUp = new HashMap<>();
+	protected Map<HostItem, Long> ratioDown = new HashMap<>();
 	protected Map<String, List<HostItem>> fileList = new HashMap<>();
 	protected volatile boolean stop;
 
@@ -62,6 +66,32 @@ public abstract class TrackerManagement extends ServeErrors implements Runnable
 		}
 	}
 
+
+	/** Handle Ratio request
+	 * @param pd	Received request
+	 * @throws	InternalError
+	 */
+	protected < T extends ProtocolP2PPacket<?> > void handleRatio(T pd) throws InternalError {
+		Payload p = pd.getPayload();
+		assert p instanceof RatioRequest : "payload must be an instance of RatioRequest";
+		if (!(p instanceof RatioRequest)) {
+			sendInternalError(pd);
+		} else {
+			HostItem host = ((RatioRequest)p).getHostItem();
+			try {
+				if (!hostList.contains(host)) {
+					pd.sendResponse(createProtocolP2PPacket(new Payload(RequestResponseCode.UNKNOWN_HOST)));
+				} else {
+					pd.sendResponse(createProtocolP2PPacket(new RatioResponse(host,
+						ratioUp.get(host).longValue(),
+						ratioDown.get(host).longValue())));
+				}
+			} catch (Exception e) {
+				writeLog(e, LogLevel.Error);
+			}
+		}
+	}
+
 	/** Handle List Responses
 	 * @param pd	Received response
 	 * @throws	InternalError
@@ -108,6 +138,10 @@ public abstract class TrackerManagement extends ServeErrors implements Runnable
 				fileList.remove(f);
 			}
 		}
+
+		/* Note: we do not remove host from ratioUp and ratioDown since Unregistering is only here to indicate
+		 * the host is temporary not serving any files (ie. is down).
+		 */ 
 	}
 
 	/** Getter for HostItem socket
@@ -135,6 +169,14 @@ public abstract class TrackerManagement extends ServeErrors implements Runnable
 		if (!hostList.contains(host)) {
 			hostList.add(host);
 		}
+
+		// initialize ratios if this is a new host
+		if (!ratioUp.containsKey(host)) {
+			ratioUp.put(host, Long.valueOf(0));
+		}
+		if (!ratioDown.containsKey(host)) {
+			ratioDown.put(host, Long.valueOf(0));
+		}
 		// send a list request
 		try {
 			ProtocolP2PPacket<?> pLReq = createProtocolP2PPacket(new Payload(RequestResponseCode.LIST_REQUEST));
@@ -186,6 +228,10 @@ public abstract class TrackerManagement extends ServeErrors implements Runnable
 				writeLog("Received DISCOVER REQUEST from host " + pd.getHostItem(), LogLevel.Action);
 				handleDiscover(pd);
 				break;
+			case RATIO_REQUEST:
+				writeLog("Received RATIO REQUEST from host " + pd.getHostItem(), LogLevel.Action);
+				handleRatio(pd);
+				break;
 			default:
 				writeLog("Received grabbage from host " + pd.getHostItem(), LogLevel.Action);
 				sendInternalError(pd);