Adiciona gerenciamento de heartbeat e peers

pitiupi/src/pitiupi/control/HeartbeatManager.java

@@ -0,0 +1,101 @@
+package pitiupi.control;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import pitiupi.GUI.MainWindow;
+import pitiupi.net.HeartbeatMessage;
+/**
+ *
+ * @author tony
+ */
+public class HeartbeatManager {
+
+    private static final long HEARTBEAT_INTERVAL_MS = 5000;
+    private static final long PEER_TIMEOUT_MS = 15000; // ~3 batimentos perdidos
+
+    private final MainWindow mainWindow;
+    private final Map<String, PeerInfo> peers = new ConcurrentHashMap<>();
+    private final List<PeerListener> listeners = new CopyOnWriteArrayList<>();
+    private ScheduledExecutorService scheduler;
+
+    public HeartbeatManager(MainWindow mainWindow) {
+        this.mainWindow = mainWindow;
+    }
+
+    public void start() {
+        scheduler = Executors.newScheduledThreadPool(1);
+        scheduler.scheduleAtFixedRate(this::announce, 0, HEARTBEAT_INTERVAL_MS, TimeUnit.MILLISECONDS);
+        scheduler.scheduleAtFixedRate(this::checkTimeouts, HEARTBEAT_INTERVAL_MS, HEARTBEAT_INTERVAL_MS, TimeUnit.MILLISECONDS);
+    }
+
+    public void stop() {
+        if (scheduler != null) {
+            scheduler.shutdownNow();
+        }
+    }
+
+    private void announce() {
+        try {
+            HeartbeatMessage msg = new HeartbeatMessage(mainWindow.getUserName());
+            mainWindow.getSocket().send(msg.toByteArray());
+        } catch (IOException ex) {
+            Logger.getLogger(HeartbeatManager.class.getName()).log(Level.WARNING, "Falha ao enviar heartbeat", ex);
+        }
+    }
+
+    // Chamado pelo Socket quando um pacote é identificado como heartbeat
+    public void receiveHeartbeat(HeartbeatMessage msg, InetAddress from) {
+        // ignora o próprio heartbeat 
+        if (msg.getUserName().equals(mainWindow.getUserName())) {
+            return;
+        }
+
+        String key = from.getHostAddress() + "#" + msg.getUserName();
+        boolean isNew = !peers.containsKey(key);
+
+        PeerInfo peer = peers.computeIfAbsent(key, k -> new PeerInfo(msg.getUserName(), from, msg.getTimestamp()));
+        peer.touch(System.currentTimeMillis());
+
+        if (isNew) {
+            notifyListeners();
+        }
+    }
+
+    private void checkTimeouts() {
+        long now = System.currentTimeMillis();
+        boolean changed = peers.values().removeIf(p -> now - p.getLastSeen() > PEER_TIMEOUT_MS);
+        if (changed) {
+            notifyListeners();
+        }
+    }
+
+    private void notifyListeners() {
+        List<PeerInfo> snapshot = new ArrayList<>(peers.values());
+        for (PeerListener l : listeners) {
+            l.onPeersChanged(snapshot);
+        }
+    }
+
+    public void addPeerListener(PeerListener l) {
+        listeners.add(l);
+        l.onPeersChanged(new ArrayList<>(peers.values()));
+    }
+
+    public void removePeerListener(PeerListener l) {
+        listeners.remove(l);
+    }
+
+    public List<PeerInfo> getPeers() {
+        return new ArrayList<>(peers.values());
+    }
+}

pitiupi/src/pitiupi/control/PeerInfo.java

@@ -0,0 +1,40 @@
+package pitiupi.control;
+
+import java.net.InetAddress;
+/**
+ *
+ * @author tony
+ */
+public class PeerInfo {
+
+    private final String userName;
+    private final InetAddress address;
+    private volatile long lastSeen;
+
+    public PeerInfo(String userName, InetAddress address, long lastSeen) {
+        this.userName = userName;
+        this.address = address;
+        this.lastSeen = lastSeen;
+    }
+
+    public String getUserName() {
+        return userName;
+    }
+
+    public InetAddress getAddress() {
+        return address;
+    }
+
+    public long getLastSeen() {
+        return lastSeen;
+    }
+
+    public void touch(long timestamp) {
+        this.lastSeen = timestamp;
+    }
+
+    @Override
+    public String toString() {
+        return userName + " (" + address.getHostAddress() + ")";
+    }
+}

pitiupi/src/pitiupi/control/PeerListener.java

@@ -0,0 +1,10 @@
+package pitiupi.control;
+
+import java.util.List;
+/**
+ *
+ * @author tony
+ */
+public interface PeerListener {
+    void onPeersChanged(List<PeerInfo> peers);
+}

pitiupi/src/pitiupi/net/HeartbeatMessage.java

@@ -0,0 +1,23 @@
+package pitiupi.net;
+/**
+ *
+ * @author tony
+ */
+public class HeartbeatMessage extends Message {
+
+    private final String userName;
+    private final long timestamp;
+
+    public HeartbeatMessage(String userName) {
+        this.userName = userName;
+        this.timestamp = System.currentTimeMillis();
+    }
+
+    public String getUserName() {
+        return userName;
+    }
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+}