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, persistenceId());
  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 {}, isLeader: {}, hasLeader: {}", persistenceId(), logName(), message,
  68                 isLeader, hasLeader);
  69
  70         ActorRef registrationActor = createActor(DataTreeNotificationListenerRegistrationActor.props());
  71
  72         if (hasLeader && message.isRegisterOnAllInstances() || isLeader) {
  73             doRegistration(message, registrationActor);
  74         } else {
  75             log.debug("{}: Shard is not the leader - delaying registration", persistenceId());
  76
  77             D delayedReg = newDelayedListenerRegistration(message, registrationActor);
  78             Collection<D> delayedRegList;
  79             if (message.isRegisterOnAllInstances()) {
  80                 delayedRegList = delayedListenerOnAllRegistrations;
  81             } else {
  82                 delayedRegList = delayedListenerRegistrations;
  83             }
  84
  85             delayedRegList.add(delayedReg);
  86             registrationActor.tell(new DataTreeNotificationListenerRegistrationActor.SetRegistration(
  87                     delayedReg, () -> delayedRegList.remove(delayedReg)), ActorRef.noSender());
  88         }
  89
  90         log.debug("{}: {} sending reply, listenerRegistrationPath = {} ", persistenceId(), logName(),
  91                 registrationActor.path());
  92
  93         tellSender(newRegistrationReplyMessage(registrationActor));
  94     }
  95
  96     protected ActorSelection processListenerRegistrationMessage(M message) {
  97         final ActorSelection listenerActor = selectActor(message.getListenerActorPath());
  98
  99         // We have a leader so enable the listener.
 100         listenerActor.tell(new EnableNotification(true, persistenceId()), getSelf());
 101
 102         if (!message.isRegisterOnAllInstances()) {
 103             // This is a leader-only registration so store a reference to the listener actor so it can be notified
 104             // at a later point if notifications should be enabled or disabled.
 105             leaderOnlyListenerActors.add(listenerActor);
 106         }
 107
 108         allListenerActors.add(listenerActor);
 109
 110         return listenerActor;
 111     }
 112
 113     protected Logger log() {
 114         return log;
 115     }
 116
 117     protected void removeListenerActor(ActorSelection listenerActor) {
 118         allListenerActors.remove(listenerActor);
 119         leaderOnlyListenerActors.remove(listenerActor);
 120     }
 121
 122     abstract void doRegistration(M message, ActorRef registrationActor);
 123
 124     protected abstract D newDelayedListenerRegistration(M message, ActorRef registrationActor);
 125
 126     protected abstract Object newRegistrationReplyMessage(ActorRef registrationActor);
 127
 128     protected abstract String logName();
 129 }