+/*
+ * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.datastore;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSelection;
+import akka.actor.PoisonPill;
+import akka.dispatch.OnComplete;
+import com.google.common.base.Preconditions;
+import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
+import org.opendaylight.controller.cluster.datastore.messages.CloseDataTreeChangeListenerRegistration;
+import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
+import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
+import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
+import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import scala.concurrent.Future;
+
+/**
+ * Proxy class for holding required state to lazily instantiate a listener registration with an
+ * asynchronously-discovered actor.
+ *
+ * @param <T> listener type
+ */
+final class DataTreeChangeListenerProxy<T extends DOMDataTreeChangeListener> extends AbstractListenerRegistration<T> {
+ private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerProxy.class);
+ private final ActorRef dataChangeListenerActor;
+ private final ActorContext actorContext;
+
+ @GuardedBy("this")
+ private ActorSelection listenerRegistrationActor;
+
+ public DataTreeChangeListenerProxy(final ActorContext actorContext, final T listener) {
+ super(listener);
+ this.actorContext = Preconditions.checkNotNull(actorContext);
+ this.dataChangeListenerActor = actorContext.getActorSystem().actorOf(
+ DataTreeChangeListenerActor.props(getInstance()).withDispatcher(actorContext.getNotificationDispatcherPath()));
+ }
+
+ @Override
+ protected synchronized void removeRegistration() {
+ if (listenerRegistrationActor != null) {
+ listenerRegistrationActor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), ActorRef.noSender());
+ listenerRegistrationActor = null;
+ }
+
+ dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
+ }
+
+ void init(final String shardName, final YangInstanceIdentifier treeId) {
+ Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
+ findFuture.onComplete(new OnComplete<ActorRef>() {
+ @Override
+ public void onComplete(final Throwable failure, final ActorRef shard) {
+ if (failure instanceof LocalShardNotFoundException) {
+ LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} " +
+ "cannot be registered", shardName, getInstance(), treeId);
+ } else if (failure != null) {
+ LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} " +
+ "cannot be registered: {}", shardName, getInstance(), treeId, failure);
+ } else {
+ doRegistration(shard, treeId);
+ }
+ }
+ }, actorContext.getClientDispatcher());
+ }
+
+ private void setListenerRegistrationActor(final ActorSelection actor) {
+ if (actor == null) {
+ LOG.debug("Ignoring null actor on {}", this);
+ return;
+ }
+
+ synchronized (this) {
+ if (!isClosed()) {
+ this.listenerRegistrationActor = actor;
+ return;
+ }
+ }
+
+ // This registration has already been closed, notify the actor
+ actor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), null);
+ }
+
+ private void doRegistration(final ActorRef shard, final YangInstanceIdentifier path) {
+
+ Future<Object> future = actorContext.executeOperationAsync(shard,
+ new RegisterDataTreeChangeListener(path, dataChangeListenerActor),
+ actorContext.getDatastoreContext().getShardInitializationTimeout());
+
+ future.onComplete(new OnComplete<Object>(){
+ @Override
+ public void onComplete(final Throwable failure, final Object result) {
+ if (failure != null) {
+ LOG.error("Failed to register DataTreeChangeListener {} at path {}",
+ getInstance(), path.toString(), failure);
+ } else {
+ RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
+ setListenerRegistrationActor(actorContext.actorSelection(
+ reply.getListenerRegistrationPath().path()));
+ }
+ }
+ }, actorContext.getClientDispatcher());
+ }
+}