opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataTreeChangeListenerProxy.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 akka.actor.PoisonPill;
  13 import akka.dispatch.OnComplete;
  14 import com.google.common.annotations.VisibleForTesting;
  15 import com.google.common.base.Preconditions;
  16 import javax.annotation.concurrent.GuardedBy;
  17 import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
  18 import org.opendaylight.controller.cluster.datastore.messages.CloseDataTreeChangeListenerRegistration;
  19 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  20 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
  21 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  22 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  23 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27 import scala.concurrent.Future;
  28
  29 /**
  30  * Proxy class for holding required state to lazily instantiate a listener registration with an
  31  * asynchronously-discovered actor.
  32  *
  33  * @param <T> listener type
  34  */
  35 final class DataTreeChangeListenerProxy<T extends DOMDataTreeChangeListener> extends AbstractListenerRegistration<T> {
  36     private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerProxy.class);
  37     private final ActorRef dataChangeListenerActor;
  38     private final ActorContext actorContext;
  39
  40     @GuardedBy("this")
  41     private ActorSelection listenerRegistrationActor;
  42
  43     public DataTreeChangeListenerProxy(final ActorContext actorContext, final T listener) {
  44         super(listener);
  45         this.actorContext = Preconditions.checkNotNull(actorContext);
  46         this.dataChangeListenerActor = actorContext.getActorSystem().actorOf(
  47             DataTreeChangeListenerActor.props(getInstance()).withDispatcher(actorContext.getNotificationDispatcherPath()));
  48     }
  49
  50     @Override
  51     protected synchronized void removeRegistration() {
  52         if (listenerRegistrationActor != null) {
  53             listenerRegistrationActor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), ActorRef.noSender());
  54             listenerRegistrationActor = null;
  55         }
  56
  57         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  58     }
  59
  60     void init(final String shardName, final YangInstanceIdentifier treeId) {
  61         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
  62         findFuture.onComplete(new OnComplete<ActorRef>() {
  63             @Override
  64             public void onComplete(final Throwable failure, final ActorRef shard) {
  65                 if (failure instanceof LocalShardNotFoundException) {
  66                     LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} " +
  67                             "cannot be registered", shardName, getInstance(), treeId);
  68                 } else if (failure != null) {
  69                     LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} " +
  70                             "cannot be registered: {}", shardName, getInstance(), treeId, failure);
  71                 } else {
  72                     doRegistration(shard, treeId);
  73                 }
  74             }
  75         }, actorContext.getClientDispatcher());
  76     }
  77
  78     private void setListenerRegistrationActor(final ActorSelection actor) {
  79         if (actor == null) {
  80             LOG.debug("Ignoring null actor on {}", this);
  81             return;
  82         }
  83
  84         synchronized (this) {
  85             if (!isClosed()) {
  86                 this.listenerRegistrationActor = actor;
  87                 return;
  88             }
  89         }
  90
  91         // This registration has already been closed, notify the actor
  92         actor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), null);
  93     }
  94
  95     private void doRegistration(final ActorRef shard, final YangInstanceIdentifier path) {
  96
  97         Future<Object> future = actorContext.executeOperationAsync(shard,
  98                 new RegisterDataTreeChangeListener(path, dataChangeListenerActor),
  99                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 100
 101         future.onComplete(new OnComplete<Object>(){
 102             @Override
 103             public void onComplete(final Throwable failure, final Object result) {
 104                 if (failure != null) {
 105                     LOG.error("Failed to register DataTreeChangeListener {} at path {}",
 106                             getInstance(), path.toString(), failure);
 107                 } else {
 108                     RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
 109                     setListenerRegistrationActor(actorContext.actorSelection(
 110                             reply.getListenerRegistrationPath()));
 111                 }
 112             }
 113         }, actorContext.getClientDispatcher());
 114     }
 115
 116     @VisibleForTesting
 117     ActorSelection getListenerRegistrationActor() {
 118         return listenerRegistrationActor;
 119     }
 120
 121     @VisibleForTesting
 122     ActorRef getDataChangeListenerActor() {
 123         return dataChangeListenerActor;
 124     }
 125 }