2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.controller.cluster.datastore;
10 import akka.actor.ActorRef;
11 import akka.actor.ActorSelection;
12 import com.google.common.base.Preconditions;
13 import java.util.ArrayList;
14 import java.util.Collection;
15 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
16 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
17 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
18 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
19 import org.opendaylight.yangtools.concepts.ListenerRegistration;
20 import org.slf4j.Logger;
21 import org.slf4j.LoggerFactory;
23 final class DataTreeChangeListenerSupport extends LeaderLocalDelegateFactory<RegisterDataTreeChangeListener, ListenerRegistration<DOMDataTreeChangeListener>> {
24 private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerSupport.class);
25 private final ArrayList<DelayedDataTreeListenerRegistration> delayedRegistrations = new ArrayList<>();
26 private final Collection<ActorSelection> actors = new ArrayList<>();
27 private final Shard shard;
29 DataTreeChangeListenerSupport(final Shard shard) {
30 this.shard = Preconditions.checkNotNull(shard);
34 void onLeadershipChange(final boolean isLeader) {
36 for (DelayedDataTreeListenerRegistration reg : delayedRegistrations) {
37 reg.createDelegate(this);
39 delayedRegistrations.clear();
40 delayedRegistrations.trimToSize();
43 final EnableNotification msg = new EnableNotification(isLeader);
44 for (ActorSelection dataChangeListener : actors) {
45 dataChangeListener.tell(msg, shard.getSelf());
50 void onMessage(final RegisterDataTreeChangeListener registerTreeChangeListener, final boolean isLeader) {
51 LOG.debug("{}: registerTreeChangeListener for {}, leader: {}", shard.persistenceId(), registerTreeChangeListener.getPath(), isLeader);
53 final ListenerRegistration<DOMDataTreeChangeListener> registration;
55 LOG.debug("{}: Shard is not the leader - delaying registration", shard.persistenceId());
57 DelayedDataTreeListenerRegistration delayedReg =
58 new DelayedDataTreeListenerRegistration(registerTreeChangeListener);
59 delayedRegistrations.add(delayedReg);
60 registration = delayedReg;
62 registration = createDelegate(registerTreeChangeListener);
65 ActorRef listenerRegistration = shard.getContext().actorOf(
66 DataTreeChangeListenerRegistrationActor.props(registration));
68 LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
69 shard.persistenceId(), listenerRegistration.path());
71 shard.getSender().tell(new RegisterDataTreeChangeListenerReply(listenerRegistration), shard.getSelf());
75 ListenerRegistration<DOMDataTreeChangeListener> createDelegate(final RegisterDataTreeChangeListener message) {
76 ActorSelection dataChangeListenerPath = shard.getContext().system().actorSelection(
77 message.getDataTreeChangeListenerPath().path());
79 // Notify the listener if notifications should be enabled or not
80 // If this shard is the leader then it will enable notifications else
82 dataChangeListenerPath.tell(new EnableNotification(true), shard.getSelf());
84 // Now store a reference to the data change listener so it can be notified
85 // at a later point if notifications should be enabled or disabled
86 actors.add(dataChangeListenerPath);
88 DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(dataChangeListenerPath);
90 LOG.debug("{}: Registering for path {}", shard.persistenceId(), message.getPath());
92 return shard.getDataStore().registerTreeChangeListener(message.getPath(), listener);