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 java.util.ArrayList;
  13 import java.util.Collection;
  14 import java.util.concurrent.ConcurrentHashMap;
  15 import org.opendaylight.controller.cluster.datastore.actors.DataTreeNotificationListenerRegistrationActor;
  16 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  17 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  18 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeNotificationListenerReply;
  19 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 final class DataTreeChangeListenerSupport extends LeaderLocalDelegateFactory<RegisterDataTreeChangeListener> {
  24     private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerSupport.class);
  25
  26     private final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>>
  27             delayedDataTreeChangeListenerRegistrations = ConcurrentHashMap.newKeySet();
  28     private final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>>
  29             delayedListenerOnAllRegistrations = ConcurrentHashMap.newKeySet();
  30     private final Collection<ActorSelection> leaderOnlyListenerActors = ConcurrentHashMap.newKeySet();
  31     private final Collection<ActorSelection> allListenerActors = ConcurrentHashMap.newKeySet();
  32
  33     DataTreeChangeListenerSupport(final Shard shard) {
  34         super(shard);
  35     }
  36
  37     void doRegistration(final RegisterDataTreeChangeListener message, final ActorRef registrationActor) {
  38         final ActorSelection listenerActor = processListenerRegistrationMessage(message);
  39
  40         final DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(listenerActor, getSelf());
  41
  42         LOG.debug("{}: Registering listenerActor {} for path {}", persistenceId(), listenerActor, message.getPath());
  43
  44         final ShardDataTree shardDataTree = getShard().getDataStore();
  45         shardDataTree.registerTreeChangeListener(message.getPath(),
  46                 listener, shardDataTree.readCurrentData(), registration -> registrationActor.tell(
  47                         new DataTreeNotificationListenerRegistrationActor.SetRegistration(registration, () ->
  48                             removeListenerActor(listenerActor)), ActorRef.noSender()));
  49     }
  50
  51     Collection<ActorSelection> getListenerActors() {
  52         return new ArrayList<>(allListenerActors);
  53     }
  54
  55     @Override
  56     void onLeadershipChange(final boolean isLeader, final boolean hasLeader) {
  57         LOG.debug("{}: onLeadershipChange, isLeader: {}, hasLeader : {}", persistenceId(), isLeader, hasLeader);
  58
  59         final EnableNotification msg = new EnableNotification(isLeader, persistenceId());
  60         for (ActorSelection dataChangeListener : leaderOnlyListenerActors) {
  61             dataChangeListener.tell(msg, getSelf());
  62         }
  63
  64         if (hasLeader) {
  65             for (DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> reg :
  66                     delayedListenerOnAllRegistrations) {
  67                 reg.doRegistration(this);
  68             }
  69
  70             delayedListenerOnAllRegistrations.clear();
  71         }
  72
  73         if (isLeader) {
  74             for (DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> reg :
  75                     delayedDataTreeChangeListenerRegistrations) {
  76                 reg.doRegistration(this);
  77             }
  78
  79             delayedDataTreeChangeListenerRegistrations.clear();
  80         }
  81     }
  82
  83     @Override
  84     void onMessage(final RegisterDataTreeChangeListener message, final boolean isLeader, final boolean hasLeader) {
  85         LOG.debug("{}: onMessage {}, isLeader: {}, hasLeader: {}", persistenceId(), message, isLeader, hasLeader);
  86
  87         final ActorRef registrationActor = createActor(DataTreeNotificationListenerRegistrationActor.props());
  88
  89         if (hasLeader && message.isRegisterOnAllInstances() || isLeader) {
  90             doRegistration(message, registrationActor);
  91         } else {
  92             LOG.debug("{}: Shard does not have a leader - delaying registration", persistenceId());
  93
  94             final DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> delayedReg =
  95                     new DelayedDataTreeChangeListenerRegistration<>(message, registrationActor);
  96             final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>> delayedRegList;
  97             if (message.isRegisterOnAllInstances()) {
  98                 delayedRegList = delayedListenerOnAllRegistrations;
  99             } else {
 100                 delayedRegList = delayedDataTreeChangeListenerRegistrations;
 101             }
 102
 103             delayedRegList.add(delayedReg);
 104             registrationActor.tell(new DataTreeNotificationListenerRegistrationActor.SetRegistration(
 105                     delayedReg, () -> delayedRegList.remove(delayedReg)), ActorRef.noSender());
 106         }
 107
 108         LOG.debug("{}: sending RegisterDataTreeNotificationListenerReply, listenerRegistrationPath = {} ",
 109                 persistenceId(), registrationActor.path());
 110
 111         tellSender(new RegisterDataTreeNotificationListenerReply(registrationActor));
 112     }
 113
 114     private ActorSelection processListenerRegistrationMessage(final RegisterDataTreeChangeListener message) {
 115         final ActorSelection listenerActor = selectActor(message.getListenerActorPath());
 116
 117         // We have a leader so enable the listener.
 118         listenerActor.tell(new EnableNotification(true, persistenceId()), getSelf());
 119
 120         if (!message.isRegisterOnAllInstances()) {
 121             // This is a leader-only registration so store a reference to the listener actor so it can be notified
 122             // at a later point if notifications should be enabled or disabled.
 123             leaderOnlyListenerActors.add(listenerActor);
 124         }
 125
 126         allListenerActors.add(listenerActor);
 127
 128         return listenerActor;
 129     }
 130
 131     private void removeListenerActor(final ActorSelection listenerActor) {
 132         allListenerActors.remove(listenerActor);
 133         leaderOnlyListenerActors.remove(listenerActor);
 134     }
 135 }