Implemented the mechanism for initiating and clearing out a remote object

proxy. Untested, but hey, it probably works. :)


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4543 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/peer/server/PeerManager.java

@@ -43,8 +43,9 @@ import com.threerings.util.Name;
 import com.threerings.presents.client.Client;
 import com.threerings.presents.client.ClientObserver;
 import com.threerings.presents.data.ClientObject;
-import com.threerings.presents.dobj.AttributeChangedEvent;
 import com.threerings.presents.dobj.AttributeChangeListener;
+import com.threerings.presents.dobj.AttributeChangedEvent;
+import com.threerings.presents.dobj.DObject;
 import com.threerings.presents.dobj.EntryAddedEvent;
 import com.threerings.presents.dobj.EntryRemovedEvent;
 import com.threerings.presents.dobj.EntryUpdatedEvent;
@@ -206,6 +207,74 @@ public class PeerManager
             creds.getPassword());
     }
 
+    /**
+     * Initiates a proxy on an object that is managed by the specified peer. The object will be
+     * proxied into this server's distributed object space and its local oid reported back to the
+     * supplied result listener.
+     *
+     * <p> Note that proxy requests <em>do not</em> stack like subscription requests. Only one
+     * entity must issue a request to proxy an object and that entity must be responsible for
+     * releasing the proxy when it knows that there are no longer any local subscribers to the
+     * object.
+     */
+    public <T extends DObject> void proxyRemoteObject (
+        String nodeName, int remoteOid, final ResultListener<Integer> listener)
+    {
+        final Client peer = getPeerClient(nodeName);
+        if (peer == null) {
+            String errmsg = "Have no connection to peer [node=" + nodeName + "].";
+            listener.requestFailed(new ObjectAccessException(errmsg));
+            return;
+        }
+
+        final Tuple<String,Integer> key = new Tuple<String,Integer>(nodeName, remoteOid);
+        if (_proxies.containsKey(key)) {
+            String errmsg = "Cannot proxy already proxied object [key=" + key + "].";
+            listener.requestFailed(new ObjectAccessException(errmsg));
+            return;
+        }
+
+        // issue a request to subscribe to the remote object
+        peer.getDObjectManager().subscribeToObject(remoteOid, new Subscriber<T>() {
+            public void objectAvailable (T object) {
+                // make a note of this proxy mapping
+                _proxies.put(key, new Tuple<Subscriber<?>,DObject>(this, object));
+                // map the object into our local oid space
+                PresentsServer.omgr.registerProxyObject(object, peer.getDObjectManager());
+                // then tell the caller about the (now remapped) oid
+                listener.requestCompleted(object.getOid());
+            }
+            public void requestFailed (int oid, ObjectAccessException cause) {
+                listener.requestFailed(cause);
+            }
+        });
+    }
+
+    /**
+     * Unsubscribes from and clears a proxied object. The caller must be sure that there are no
+     * remaining subscribers to the object on this local server.
+     */
+    public void unproxyRemoteObject (String nodeName, int remoteOid)
+    {
+        Tuple<String,Integer> key = new Tuple<String,Integer>(nodeName, remoteOid);
+        Tuple<Subscriber<?>,DObject> bits = _proxies.remove(key);
+        if (bits == null) {
+            log.warning("Requested to clear unknown proxy [key=" + key + "].");
+            return;
+        }
+
+        // clear out the local object manager's proxy mapping
+        PresentsServer.omgr.clearProxyObject(remoteOid, bits.right);
+
+        // now unsubscribe from the object on our peer
+        final Client peer = getPeerClient(nodeName);
+        if (peer == null) {
+            log.warning("Unable to unsubscribe from proxy, missing peer [key=" + key + "].");
+            return;
+        }
+        peer.getDObjectManager().unsubscribeFromObject(remoteOid, bits.left);
+    }
+
     /**
      * Returns the client object representing the connection to the named peer, or
      * <code>null</code> if we are not currently connected to it.
@@ -850,6 +919,10 @@ public class PeerManager
     protected NodeObject _nodeobj;
     protected HashMap<String,PeerNode> _peers = new HashMap<String,PeerNode>();
 
+    /** Contains a mapping of proxied objects to subscriber instances. */
+    protected HashMap<Tuple<String,Integer>,Tuple<Subscriber<?>,DObject>> _proxies =
+        new HashMap<Tuple<String,Integer>,Tuple<Subscriber<?>,DObject>>();
+
     /** Our stale cache observers. */
     protected HashMap<String, ObserverList<StaleCacheObserver>> _cacheobs =
         new HashMap<String, ObserverList<StaleCacheObserver>>();

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

@@ -120,6 +120,19 @@ public class PresentsDObjectMgr
         _proxies.put(origObjectId, new ProxyReference(object.getOid(), omgr));
     }
 
+    /**
+     * Clears a proxy object reference from our local distributed object space. This merely removes
+     * it from our internal tables, the caller is responsible for coordinating the deregistration
+     * of the object with the proxying client.
+     */
+    public void clearProxyObject (int origObjectId, DObject object)
+    {
+        if (_proxies.remove(origObjectId) == null) {
+            log.warning("Missing proxy mapping for cleared proxy [ooid=" + origObjectId + "].");
+        }
+        _objects.remove(object.getOid());
+    }
+
     // from interface DObjectManager
     public boolean isManager (DObject object)
     {