3 files changed, 46 insertions, 0 deletions
diff --git a/src/main/java/derms/net/rmulticast/Hashable.java b/src/main/java/derms/net/rmulticast/Hashable.java
new file mode 100644
index 0000000..f00f62b
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/Hashable.java
@@ -0,0 +1,5 @@
+package derms.net.rmulticast;
+
+public interface Hashable {
+    int hash();
+}
diff --git a/src/main/java/derms/net/rmulticast/Message.java b/src/main/java/derms/net/rmulticast/Message.java
new file mode 100644
index 0000000..6df283e
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/Message.java
@@ -0,0 +1,27 @@
+package derms.net.rmulticast;
+
+import java.io.Serializable;
+import java.net.InetAddress;
+
+class Message<T extends Serializable & Hashable> implements Serializable {
+    T payload;
+    InetAddress sender;
+    MessageID[] positiveAcks; // IDs of messages that this message positively acknowledges.
+    MessageID[] negativeAcks; // IDs of messages that this message negatively acknowledges.
+
+    Message(T payload, InetAddress sender, MessageID[] positiveAcks, MessageID[] negativeAcks) {
+        this.payload = payload;
+        this.sender = sender;
+        this.positiveAcks = positiveAcks;
+        this.negativeAcks = negativeAcks;
+    }
+
+    MessageID id() {
+        return new MessageID(hashCode());
+    }
+
+    @Override
+    public int hashCode() {
+        return payload.hash();
+    }
+}
diff --git a/src/main/java/derms/net/rmulticast/MessageID.java b/src/main/java/derms/net/rmulticast/MessageID.java
new file mode 100644
index 0000000..e6824ad
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/MessageID.java
@@ -0,0 +1,14 @@
+package derms.net.rmulticast;
+
+class MessageID {
+    int id;
+
+    MessageID(int id) {
+        this.id = id;
+    }
+
+    @Override
+    public int hashCode() {
+        return id;
+    }
+}