Adding some base-classes to eliminate event and listener boiler-plate code throughout a number of subsystems.
Refactored all core components to take advantage of this; apps remain to be done.
Change-Id: Ib0935ba07ff81b0fa032534004ec9ac6187cbf22
diff --git a/core/api/src/main/java/org/onosproject/event/AbstractListenerManager.java b/core/api/src/main/java/org/onosproject/event/AbstractListenerManager.java
new file mode 100644
index 0000000..cbe7421
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/event/AbstractListenerManager.java
@@ -0,0 +1,58 @@
+/*
+ * 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.event;
+
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+
+/**
+ * Basis for components which need to export listener mechanism.
+ */
+@Component(componentAbstract = true)
+public abstract class AbstractListenerManager<E extends Event, L extends EventListener<E>>
+ implements ListenerService<E, L> {
+
+ protected final ListenerRegistry<E, L> listenerRegistry = new ListenerRegistry<>();
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected EventDeliveryService eventDispatcher;
+
+ @Override
+ public void addListener(L listener) {
+ listenerRegistry.addListener(listener);
+ }
+
+ @Override
+ public void removeListener(L listener) {
+ listenerRegistry.removeListener(listener);
+ }
+
+
+ /**
+ * Safely posts the specified event to the local event dispatcher.
+ * If there is no event dispatcher or if the event is null, this method
+ * is a noop.
+ *
+ * @param event event to be posted; may be null
+ */
+ protected void post(E event) {
+ if (event != null && eventDispatcher != null) {
+ eventDispatcher.post(event);
+ }
+ }
+
+}
diff --git a/core/api/src/main/java/org/onosproject/event/ListenerRegistry.java b/core/api/src/main/java/org/onosproject/event/ListenerRegistry.java
index e6af201..ef02af06 100644
--- a/core/api/src/main/java/org/onosproject/event/ListenerRegistry.java
+++ b/core/api/src/main/java/org/onosproject/event/ListenerRegistry.java
@@ -28,7 +28,7 @@
* listeners and dispatching events to them as part of event sink processing.
*/
public class ListenerRegistry<E extends Event, L extends EventListener<E>>
- implements EventSink<E> {
+ implements ListenerService<E, L>, EventSink<E> {
private static final long LIMIT = 1_800; // ms
@@ -42,22 +42,13 @@
*/
protected final Set<L> listeners = new CopyOnWriteArraySet<>();
-
- /**
- * Adds the specified listener.
- *
- * @param listener listener to be added
- */
+ @Override
public void addListener(L listener) {
checkNotNull(listener, "Listener cannot be null");
listeners.add(listener);
}
- /**
- * Removes the specified listener.
- *
- * @param listener listener to be removed
- */
+ @Override
public void removeListener(L listener) {
checkNotNull(listener, "Listener cannot be null");
if (!listeners.remove(listener)) {
diff --git a/core/api/src/main/java/org/onosproject/event/ListenerService.java b/core/api/src/main/java/org/onosproject/event/ListenerService.java
new file mode 100644
index 0000000..a4a3631
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/event/ListenerService.java
@@ -0,0 +1,38 @@
+/*
+ * 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.event;
+
+/**
+ * Abstraction of a service capable of asynchronously notifying listeners.
+ */
+public interface ListenerService<E extends Event, L extends EventListener<E>> {
+
+ /**
+ * Adds the specified listener.
+ *
+ * @param listener listener to be added
+ */
+ void addListener(L listener);
+
+ /**
+ * Removes the specified listener.
+ *
+ * @param listener listener to be removed
+ */
+ void removeListener(L listener);
+
+
+}