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