opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataTreeChangeListenerSupport.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   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
   7  */
   8 package org.opendaylight.controller.cluster.datastore;
   9
  10 import akka.actor.ActorRef;
  11 import akka.actor.ActorSelection;
  12 import com.google.common.base.Optional;
  13 import com.google.common.collect.Sets;
  14 import java.util.ArrayList;
  15 import java.util.Collection;
  16 import java.util.Map.Entry;
  17 import java.util.Set;
  18 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  19 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  20 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
  21 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  22 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  24
  25 final class DataTreeChangeListenerSupport extends AbstractDataListenerSupport<DOMDataTreeChangeListener,
  26         RegisterDataTreeChangeListener, DelayedDataTreeListenerRegistration,
  27         ListenerRegistration<DOMDataTreeChangeListener>> {
  28
  29     private final Set<ActorSelection> listenerActors = Sets.newConcurrentHashSet();
  30
  31     DataTreeChangeListenerSupport(final Shard shard) {
  32         super(shard);
  33     }
  34
  35     Collection<ActorSelection> getListenerActors() {
  36         return new ArrayList<>(listenerActors);
  37     }
  38
  39     @Override
  40     ListenerRegistration<DOMDataTreeChangeListener> createDelegate(
  41             final RegisterDataTreeChangeListener message) {
  42         final ActorSelection dataChangeListenerPath = selectActor(message.getDataTreeChangeListenerPath());
  43
  44         // Notify the listener if notifications should be enabled or not
  45         // If this shard is the leader then it will enable notifications else
  46         // it will not
  47         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
  48
  49         // Now store a reference to the data change listener so it can be notified
  50         // at a later point if notifications should be enabled or disabled
  51         if (!message.isRegisterOnAllInstances()) {
  52             addListenerActor(dataChangeListenerPath);
  53         }
  54
  55         DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(dataChangeListenerPath);
  56
  57         log().debug("{}: Registering for path {}", persistenceId(), message.getPath());
  58
  59         Entry<ListenerRegistration<DOMDataTreeChangeListener>, Optional<DataTreeCandidate>> regEntry =
  60                 getShard().getDataStore().registerTreeChangeListener(message.getPath(), listener);
  61
  62         getShard().getDataStore().notifyOfInitialData(message.getPath(),
  63                 regEntry.getKey().getInstance(), regEntry.getValue());
  64
  65         listenerActors.add(dataChangeListenerPath);
  66         final ListenerRegistration<DOMDataTreeChangeListener> delegate = regEntry.getKey();
  67         return new ListenerRegistration<DOMDataTreeChangeListener>() {
  68             @Override
  69             public DOMDataTreeChangeListener getInstance() {
  70                 return delegate.getInstance();
  71             }
  72
  73             @Override
  74             public void close() {
  75                 listenerActors.remove(dataChangeListenerPath);
  76                 delegate.close();
  77             }
  78         };
  79     }
  80
  81     @Override
  82     protected DelayedDataTreeListenerRegistration newDelayedListenerRegistration(
  83             RegisterDataTreeChangeListener message) {
  84         return new DelayedDataTreeListenerRegistration(message);
  85     }
  86
  87     @Override
  88     protected ActorRef newRegistrationActor(ListenerRegistration<DOMDataTreeChangeListener> registration) {
  89         return createActor(DataTreeChangeListenerRegistrationActor.props(registration));
  90     }
  91
  92     @Override
  93     protected Object newRegistrationReplyMessage(ActorRef registrationActor) {
  94         return new RegisterDataTreeChangeListenerReply(registrationActor);
  95     }
  96
  97     @Override
  98     protected String logName() {
  99         return "registerTreeChangeListener";
 100     }
 101 }