Forgot to commit the RegistrationService implementation on Saturday

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6275 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/main/java/com/threerings/presents/server/RegistrationManager.java

@@ -0,0 +1,19 @@
+package com.threerings.presents.server;
+
+import com.threerings.presents.client.InvocationReceiver.Registration;
+import com.threerings.presents.data.ClientObject;
+
+/**
+ * Adds receiver registrations for a client.  Must be added to an invocation dispatcher to be used.
+ */
+public class RegistrationManager implements RegistrationProvider
+{
+    public void registerReceiver (ClientObject caller, Registration reg)
+    {
+        if (caller.receivers.containsKey(reg.getKey())) {
+            caller.updateReceivers(reg);
+        } else {
+            caller.addToReceivers(reg);
+        }
+    }
+}