GUI -- Further work on refactoring Topology View server side code. Still WIP...
- added topology client heartbeat.
- modified AbstractListenerRegistry to allow for extension.
Change-Id: Ib8ea6ad4ba34f5732d062f1c9ef545f105eb167b
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/topo/ModelListenerRegistry.java b/web/gui/src/main/java/org/onosproject/ui/impl/topo/ModelListenerRegistry.java
new file mode 100644
index 0000000..04c6b72
--- /dev/null
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/topo/ModelListenerRegistry.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.onosproject.ui.impl.topo;
+
+import org.onosproject.event.AbstractListenerRegistry;
+import org.slf4j.Logger;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * A listener registry that automatically prunes listeners that have not
+ * been sending heartbeat messages to assure us they are really listening.
+ */
+// package private
+class ModelListenerRegistry
+ extends AbstractListenerRegistry<TopoUiEvent, TopoUiListener> {
+
+ private final Logger log = getLogger(getClass());
+
+ private final Set<TopoUiListener> zombies = new HashSet<>();
+
+ @Override
+ public void process(TopoUiEvent event) {
+ zombies.clear();
+ for (TopoUiListener listener : listeners) {
+ try {
+ if (listener.isAwake()) {
+ listener.event(event);
+ } else {
+ zombies.add(listener);
+ }
+ } catch (Exception error) {
+ reportProblem(event, error);
+ }
+ }
+
+ // clean up zombie listeners
+ for (TopoUiListener z : zombies) {
+ log.debug("Removing zombie model listener: {}", z);
+ removeListener(z);
+ }
+ }
+}