1 files changed, 68 insertions, 0 deletions
diff --git a/src/main/java/derms/net/rmulticast/Receive.java b/src/main/java/derms/net/rmulticast/Receive.java
new file mode 100644
index 0000000..c8467c2
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/Receive.java
@@ -0,0 +1,68 @@
+package derms.net.rmulticast;
+
+import derms.net.ConcurrentMulticastSocket;
+import derms.net.Packet;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.net.DatagramPacket;
+import java.util.Set;
+import java.util.concurrent.BlockingQueue;
+import java.util.logging.Logger;
+
+class Receive<T extends Serializable & Hashable> implements Runnable {
+    private static final int bufSize = 8192;
+
+    private final ConcurrentMulticastSocket inSock;
+    private final Set<MessageID> positiveAcks;
+    private final Set<MessageID> negativeAcks;
+    private final ReceivedSet<T> received;
+    private final BlockingQueue<Message<T>> retransmissions;
+    private final Logger log;
+
+    Receive(ConcurrentMulticastSocket inSock, Set<MessageID> positiveAcks, Set<MessageID> negativeAcks, ReceivedSet<T> received, BlockingQueue<Message<T>> retransmissions) {
+        this.inSock = inSock;
+        this.positiveAcks = positiveAcks;
+        this.negativeAcks = negativeAcks;
+        this.received = received;
+        this.retransmissions = retransmissions;
+        this.log = Logger.getLogger(this.getClass().getName());
+    }
+
+    @Override
+    public void run() {
+        DatagramPacket pkt = new DatagramPacket(new byte[bufSize], bufSize);
+        Message<T> msg;
+        for (;;) {
+            try {
+                inSock.receive(pkt);
+                msg = Packet.decode(pkt, Message.class);
+                receive(msg);
+            } catch (IOException | ClassNotFoundException | ClassCastException e) {
+                log.warning(e.getMessage());
+            }
+        }
+    }
+
+    private void receive(Message<T> msg) {
+        positiveAcks.add(msg.id());
+        received.add(msg);
+
+        negativeAcks.remove(msg.id());
+        retransmissions.remove(msg);
+
+        for (MessageID mid : msg.positiveAcks) {
+            positiveAcks.remove(mid);
+            if (!received.contains(mid))
+                negativeAcks.add(mid);
+        }
+
+        for (MessageID mid : msg.negativeAcks) {
+            if (received.contains(mid)) {
+                retransmissions.add(msg);
+            } else {
+                negativeAcks.add(mid);
+            }
+        }
+    }
+}