1 files changed, 60 insertions, 0 deletions
diff --git a/src/main/java/derms/net/runicast/Receive.java b/src/main/java/derms/net/runicast/Receive.java
new file mode 100644
index 0000000..584861b
--- /dev/null
+++ b/src/main/java/derms/net/runicast/Receive.java
@@ -0,0 +1,60 @@
+package derms.net.runicast;
+
+import derms.net.ConcurrentDatagramSocket;
+import derms.net.MessagePayload;
+import derms.net.Packet;
+
+import java.io.IOException;
+import java.net.*;
+import java.util.Queue;
+import java.util.logging.Logger;
+
+class Receive<T extends MessagePayload> implements Runnable {
+    private static final int bufSize = 8192;
+
+    private long seq; // Sequence number.
+    private final ConcurrentDatagramSocket sock;
+    private final Queue<T> delivered;
+    private final Logger log;
+
+    Receive(ConcurrentDatagramSocket sock, Queue<T> delivered) {
+        this.seq = 0;
+        this.sock = sock;
+        this.delivered = delivered;
+        this.log = Logger.getLogger(getClass().getName());
+    }
+
+    @Override
+    public void run() {
+        DatagramPacket pkt = new DatagramPacket(new byte[bufSize], bufSize);
+        for (;;) {
+            try {
+                sock.receive(pkt);
+                Message<T> msg = (Message<T>) Packet.decode(pkt, Message.class);
+                SocketAddress sender = pkt.getSocketAddress();
+                recv(msg, sender);
+            } catch (SocketTimeoutException e) {
+                if (Thread.interrupted()) {
+                    log.info("Interrupted");
+                    return;
+                }
+            } catch (IOException | ClassNotFoundException | ClassCastException e) {
+                log.warning(e.getMessage());
+            }
+        }
+    }
+
+    private void recv(Message<T> msg, SocketAddress sender) throws IOException {
+        if (msg.seq == seq) {
+            delivered.add(msg.payload);
+            ack(msg, sender);
+            seq++;
+        }
+    }
+
+    private void ack(Message<T> msg, SocketAddress sender) throws IOException {
+        Ack ack = new Ack(msg.seq);
+        DatagramPacket pkt = Packet.encode(ack, sender);
+        sock.send(pkt);
+    }
+}