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.Collection;
  15 import java.util.Collections;
  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, ListenerRegistration<DOMDataTreeChangeListener>> {
  27
  28     private final Set<ActorSelection> listenerActors = Sets.newConcurrentHashSet();
  29
  30     DataTreeChangeListenerSupport(final Shard shard) {
  31         super(shard);
  32     }
  33
  34     Collection<ActorSelection> getListenerActors() {
  35         return Collections.unmodifiableCollection(listenerActors);
  36     }
  37
  38     @Override
  39     ListenerRegistration<DOMDataTreeChangeListener> createDelegate(
  40             final RegisterDataTreeChangeListener message) {
  41         final ActorSelection dataChangeListenerPath = selectActor(message.getDataTreeChangeListenerPath());
  42
  43         // Notify the listener if notifications should be enabled or not
  44         // If this shard is the leader then it will enable notifications else
  45         // it will not
  46         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
  47
  48         // Now store a reference to the data change listener so it can be notified
  49         // at a later point if notifications should be enabled or disabled
  50         if(!message.isRegisterOnAllInstances()) {
  51             addListenerActor(dataChangeListenerPath);
  52         }
  53
  54         DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(dataChangeListenerPath);
  55
  56         log().debug("{}: Registering for path {}", persistenceId(), message.getPath());
  57
  58         Entry<ListenerRegistration<DOMDataTreeChangeListener>, Optional<DataTreeCandidate>> regEntry =
  59                 getShard().getDataStore().registerTreeChangeListener(message.getPath(), listener);
  60
  61         getShard().getDataStore().notifyOfInitialData(message.getPath(),
  62                 regEntry.getKey().getInstance(), regEntry.getValue());
  63
  64         listenerActors.add(dataChangeListenerPath);
  65         final ListenerRegistration<DOMDataTreeChangeListener> delegate = regEntry.getKey();
  66         return new ListenerRegistration<DOMDataTreeChangeListener>() {
  67             @Override
  68             public DOMDataTreeChangeListener getInstance() {
  69                 return delegate.getInstance();
  70             }
  71
  72             @Override
  73             public void close() {
  74                 listenerActors.remove(dataChangeListenerPath);
  75                 delegate.close();
  76             }
  77         };
  78     }
  79
  80     @Override
  81     protected DelayedDataTreeListenerRegistration newDelayedListenerRegistration(RegisterDataTreeChangeListener message) {
  82         return new DelayedDataTreeListenerRegistration(message);
  83     }
  84
  85     @Override
  86     protected ActorRef newRegistrationActor(ListenerRegistration<DOMDataTreeChangeListener> registration) {
  87         return createActor(DataTreeChangeListenerRegistrationActor.props(registration));
  88     }
  89
  90     @Override
  91     protected Object newRegistrationReplyMessage(ActorRef registrationActor) {
  92         return new RegisterDataTreeChangeListenerReply(registrationActor);
  93     }
  94
  95     @Override
  96     protected String logName() {
  97         return "registerTreeChangeListener";
  98     }
  99 }