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