1 files changed, 25 insertions, 0 deletions
diff --git a/src/main/java/derms/net/rmulticast/ReceivedSet.java b/src/main/java/derms/net/rmulticast/ReceivedSet.java
new file mode 100644
index 0000000..339a714
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/ReceivedSet.java
@@ -0,0 +1,25 @@
+package derms.net.rmulticast;
+
+import java.io.Serializable;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+class ReceivedSet<T extends Serializable & Hashable> {
+    private final Set<Message<T>> received;
+
+    ReceivedSet() {
+        this.received = new ConcurrentHashMap<Message<T>, Void>().keySet();
+    }
+
+    void add(Message<T> e) {
+        received.add(e);
+    }
+
+    // TODO: faster search.
+    boolean contains(MessageID mid) {
+        for (Message<T> msg : received)
+            if (msg.id().equals(mid))
+                return true;
+        return false;
+    }
+}