3 files changed, 79 insertions, 0 deletions
diff --git a/same/src/main/java/com/orbekk/same/discovery/DirectoryService.java b/same/src/main/java/com/orbekk/same/discovery/DirectoryService.java
new file mode 100644
index 0000000..fae2bf6
--- /dev/null
+++ b/same/src/main/java/com/orbekk/same/discovery/DirectoryService.java
@@ -0,0 +1,22 @@
+package com.orbekk.same.discovery;
+
+import java.util.List;
+
+/**
+ * Maintains a registry of available networks.
+ * 
+ * The discovery service is only meant to be used for debugging.
+ */
+public interface DirectoryService {
+    /**
+     * Returns a list of network names and master urls interleaved, i.e.,
+     * 
+     *   [NetworkName1, MasterUrl1, ...]
+     */
+    List<String> getNetworks() throws Exception;
+    
+    /**
+     * Register a network.
+     */
+    void registerNetwork(String networkName, String masterUrl) throws Exception;
+}
diff --git a/same/src/main/java/com/orbekk/same/discovery/DiscoveryListener.java b/same/src/main/java/com/orbekk/same/discovery/DiscoveryListener.java
new file mode 100644
index 0000000..e006c77
--- /dev/null
+++ b/same/src/main/java/com/orbekk/same/discovery/DiscoveryListener.java
@@ -0,0 +1,5 @@
+package com.orbekk.same.discovery;
+
+public interface DiscoveryListener {
+    void discover(String url);
+}
diff --git a/same/src/main/java/com/orbekk/same/discovery/DiscoveryService.java b/same/src/main/java/com/orbekk/same/discovery/DiscoveryService.java
new file mode 100644
index 0000000..a1147cc
--- /dev/null
+++ b/same/src/main/java/com/orbekk/same/discovery/DiscoveryService.java
@@ -0,0 +1,52 @@
+package com.orbekk.same.discovery;
+
+import java.net.DatagramPacket;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.orbekk.net.BroadcastListener;
+
+public class DiscoveryService extends Thread {
+    private Logger logger = LoggerFactory.getLogger(getClass());
+    BroadcastListener broadcastListener;
+    DiscoveryListener listener;
+
+    public DiscoveryService(DiscoveryListener listener,
+            BroadcastListener broadcastListener) {
+        this.listener = listener;
+        this.broadcastListener = broadcastListener;
+    }
+
+    @Override
+    public void run() {
+        logger.info("DiscoveryService starting.");
+        while (!Thread.interrupted()) {
+            DatagramPacket packet = broadcastListener.listen();
+            if (packet == null) {
+                // An error or interrupt occurred.
+                continue;
+            }
+            String content = new String(packet.getData(), 0, packet.getLength());
+            String[] words = content.split(" ");
+
+            if (!content.startsWith("Discover") || words.length < 2) {
+                logger.warn("Invalid discovery message: {}", content);
+                continue;
+            }
+
+            String url = words[1];
+            logger.info("Received discovery from {}", url);
+            if (listener != null) {
+                listener.discover(url);
+            }
+        }
+        logger.info("DiscoveryService stopped.");
+    }
+
+    @Override public void interrupt() {
+        logger.info("Interrupt()");
+        super.interrupt();
+        broadcastListener.interrupt();
+    }
+}