Wired up the remainder of event dispatch and added facilities for cleaning

up after objects when they have no more subscribers.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@38 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/client/ClientDObjectMgr.java

@@ -1,5 +1,5 @@
 //
-// $Id: ClientDObjectMgr.java,v 1.2 2001/06/11 17:44:04 mdb Exp $
+// $Id: ClientDObjectMgr.java,v 1.3 2001/06/13 05:17:54 mdb Exp $
 
 package com.threerings.cocktail.cher.client;
 
@@ -53,9 +53,6 @@ public class ClientDObjectMgr
     public void unsubscribeFromObject (int oid, Subscriber target)
     {
         queueAction(oid, target, false);
-
-        // forward an unsubscribe request to the server
-        _comm.postMessage(new UnsubscribeRequest(oid));
     }
 
     protected void queueAction (int oid, Subscriber target, boolean subscribe)
@@ -78,6 +75,17 @@ public class ClientDObjectMgr
         _comm.postMessage(new ForwardEventRequest(tevent));
     }
 
+    // inherit documentation from the interface
+    public void removedLastSubscriber (DObject obj)
+    {
+        // if object has no subscribers, we no longer need to proxy it;
+        // first remove it from the object table
+        _ocache.remove(obj.getOid());
+
+        // then ship off an unsubscribe message to the server
+        _comm.postMessage(new UnsubscribeRequest(obj.getOid()));
+    }
+
     /**
      * Called by the communicator when a downstream message arrives from
      * the network layer. We queue it up for processing and request some
@@ -141,6 +149,9 @@ public class ClientDObjectMgr
                      "object [event=" + event + "].");
             return;
         }
+
+        // have the object pass this event on to its subscribers
+        target.notifySubscribers(event);
     }
 
     /**
@@ -165,6 +176,9 @@ public class ClientDObjectMgr
 
         for (int i = 0; i < req.targets.size(); i++) {
             Subscriber target = (Subscriber)req.targets.get(i);
+            // add them as a subscriber
+            obj.addSubscriber(target);
+            // and let them know that the object is in
             target.objectAvailable(obj);
         }
     }

src/java/com/threerings/presents/dobj/DObject.java

@@ -1,11 +1,13 @@
 //
-// $Id: DObject.java,v 1.10 2001/06/12 02:57:30 mdb Exp $
+// $Id: DObject.java,v 1.11 2001/06/13 05:17:55 mdb Exp $
 
 package com.threerings.cocktail.cher.dobj;
 
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 
+import com.threerings.cocktail.cher.Log;
+
 /**
  * The distributed object forms the foundation of the cocktail system. All
  * information shared among users of the system is done via distributed
@@ -118,7 +120,13 @@ public class DObject
      */
     public void removeSubscriber (Subscriber sub)
     {
-        _subscribers.remove(sub);
+        if (_subscribers.remove(sub)) {
+            // if we removed something, check to see if we just removed
+            // the last subscriber from our list
+            if (_subscribers.size() == 0) {
+                _mgr.removedLastSubscriber(this);
+            }
+        }
     }
 
     /**
@@ -163,6 +171,9 @@ public class DObject
      */
     public void notifySubscribers (DEvent event)
     {
+        Log.info("Dispatching event to " + _subscribers.size() +
+                 " subscribers: " + event);
+
         for (int i = 0; i < _subscribers.size(); i++) {
             Subscriber sub = (Subscriber)_subscribers.get(i);
             // notify the subscriber
@@ -170,6 +181,12 @@ public class DObject
                 // if they return false, we need to remove them from the
                 // subscriber list
                 _subscribers.remove(i--);
+
+                // if we just removed our last subscriber, we need to let
+                // the omgr know about it
+                if (_subscribers.size() == 0) {
+                    _mgr.removedLastSubscriber(this);
+                }
             }
         }
     }

src/java/com/threerings/presents/dobj/DObjectManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: DObjectManager.java,v 1.5 2001/06/09 23:39:04 mdb Exp $
+// $Id: DObjectManager.java,v 1.6 2001/06/13 05:17:55 mdb Exp $
 
 package com.threerings.cocktail.cher.dobj;
 
@@ -76,4 +76,12 @@ public interface DObjectManager
      * @param event The event to be dispatched.
      */
     public void postEvent (DEvent event);
+
+    /**
+     * When a distributed object removes its last subscriber, it will call
+     * this function to let the object manager know. The manager might
+     * then choose to flush this object from the system or unregister from
+     * some upstream manager whose object it was proxying, for example.
+     */
+    public void removedLastSubscriber (DObject obj);
 }

src/java/com/threerings/presents/server/PresentsDObjectMgr.java

@@ -1,5 +1,5 @@
 //
-// $Id: PresentsDObjectMgr.java,v 1.5 2001/06/09 23:39:04 mdb Exp $
+// $Id: PresentsDObjectMgr.java,v 1.6 2001/06/13 05:17:55 mdb Exp $
 
 package com.threerings.cocktail.cher.server;
 
@@ -68,6 +68,12 @@ public class CherDObjectMgr implements DObjectManager
         _evqueue.append(event);
     }
 
+    // inherit documentation from the interface
+    public void removedLastSubscriber (DObject obj)
+    {
+        // nothing to do here, our objects live forever!
+    }
+
     /**
      * Runs the dobjmgr event loop until it is requested to exit. This
      * should be called from the main application thread.

tests/src/java/com/threerings/presents/client/TestClient.java

@@ -1,5 +1,5 @@
 //
-// $Id: TestClient.java,v 1.3 2001/06/09 23:39:03 mdb Exp $
+// $Id: TestClient.java,v 1.4 2001/06/13 05:17:55 mdb Exp $
 
 package com.threerings.cocktail.cher.client.test;
 
@@ -79,7 +79,10 @@ public class TestClient
     public boolean handleEvent (DEvent event, DObject target)
     {
         Log.info("Got event [event=" + event + ", target=" + target + "].");
-        return true;
+        // dispatch a second event
+        ((TestObject)target).setBar("rofl!");
+        // unsubscribe to the object to make sure we don't get the event
+        return false;
     }
 
     public static void main (String[] args)