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

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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.EventListener;
  15 import java.util.concurrent.ConcurrentHashMap;
  16 import org.opendaylight.controller.cluster.datastore.actors.DataTreeNotificationListenerRegistrationActor;
  17 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  18 import org.opendaylight.controller.cluster.datastore.messages.ListenerRegistrationMessage;
  19 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeNotificationListenerReply;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 abstract class AbstractDataListenerSupport<L extends EventListener, M extends ListenerRegistrationMessage>
  24         extends LeaderLocalDelegateFactory<M> {
  25     private final Logger log = LoggerFactory.getLogger(getClass());
  26
  27     private final Collection<DelayedListenerRegistration<L, M>> delayedListenerRegistrations =
  28             ConcurrentHashMap.newKeySet();
  29     private final Collection<DelayedListenerRegistration<L, M>> delayedListenerOnAllRegistrations =
  30             ConcurrentHashMap.newKeySet();
  31     private final Collection<ActorSelection> leaderOnlyListenerActors = ConcurrentHashMap.newKeySet();
  32     private final Collection<ActorSelection> allListenerActors = ConcurrentHashMap.newKeySet();
  33
  34     protected AbstractDataListenerSupport(Shard shard) {
  35         super(shard);
  36     }
  37
  38     Collection<ActorSelection> getListenerActors() {
  39         return new ArrayList<>(allListenerActors);
  40     }
  41
  42     @Override
  43     void onLeadershipChange(boolean isLeader, boolean hasLeader) {
  44         log.debug("{}: onLeadershipChange, isLeader: {}, hasLeader : {}", persistenceId(), isLeader, hasLeader);
  45
  46         final EnableNotification msg = new EnableNotification(isLeader, persistenceId());
  47         for (ActorSelection dataChangeListener : leaderOnlyListenerActors) {
  48             dataChangeListener.tell(msg, getSelf());
  49         }
  50
  51         if (hasLeader) {
  52             for (DelayedListenerRegistration<L, M> reg : delayedListenerOnAllRegistrations) {
  53                 reg.doRegistration(this);
  54             }
  55
  56             delayedListenerOnAllRegistrations.clear();
  57         }
  58
  59         if (isLeader) {
  60             for (DelayedListenerRegistration<L, M> reg : delayedListenerRegistrations) {
  61                 reg.doRegistration(this);
  62             }
  63
  64             delayedListenerRegistrations.clear();
  65         }
  66     }
  67
  68     @Override
  69     void onMessage(M message, boolean isLeader, boolean hasLeader) {
  70         log.debug("{}: {} for {}, isLeader: {}, hasLeader: {}", persistenceId(), logName(), message,
  71                 isLeader, hasLeader);
  72
  73         ActorRef registrationActor = createActor(DataTreeNotificationListenerRegistrationActor.props());
  74
  75         if (hasLeader && message.isRegisterOnAllInstances() || isLeader) {
  76             doRegistration(message, registrationActor);
  77         } else {
  78             log.debug("{}: Shard is not the leader - delaying registration", persistenceId());
  79
  80             DelayedListenerRegistration<L, M> delayedReg =
  81                     new DelayedListenerRegistration<>(message, registrationActor);
  82             Collection<DelayedListenerRegistration<L, M>> delayedRegList;
  83             if (message.isRegisterOnAllInstances()) {
  84                 delayedRegList = delayedListenerOnAllRegistrations;
  85             } else {
  86                 delayedRegList = delayedListenerRegistrations;
  87             }
  88
  89             delayedRegList.add(delayedReg);
  90             registrationActor.tell(new DataTreeNotificationListenerRegistrationActor.SetRegistration(
  91                     delayedReg, () -> delayedRegList.remove(delayedReg)), ActorRef.noSender());
  92         }
  93
  94         log.debug("{}: {} sending reply, listenerRegistrationPath = {} ", persistenceId(), logName(),
  95                 registrationActor.path());
  96
  97         tellSender(new RegisterDataTreeNotificationListenerReply(registrationActor));
  98     }
  99
 100     protected ActorSelection processListenerRegistrationMessage(M message) {
 101         final ActorSelection listenerActor = selectActor(message.getListenerActorPath());
 102
 103         // We have a leader so enable the listener.
 104         listenerActor.tell(new EnableNotification(true, persistenceId()), getSelf());
 105
 106         if (!message.isRegisterOnAllInstances()) {
 107             // This is a leader-only registration so store a reference to the listener actor so it can be notified
 108             // at a later point if notifications should be enabled or disabled.
 109             leaderOnlyListenerActors.add(listenerActor);
 110         }
 111
 112         allListenerActors.add(listenerActor);
 113
 114         return listenerActor;
 115     }
 116
 117     protected Logger log() {
 118         return log;
 119     }
 120
 121     protected void removeListenerActor(ActorSelection listenerActor) {
 122         allListenerActors.remove(listenerActor);
 123         leaderOnlyListenerActors.remove(listenerActor);
 124     }
 125
 126     abstract void doRegistration(M message, ActorRef registrationActor);
 127
 128     protected abstract String logName();
 129 }