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.ClusteredDOMDataTreeChangeListener;
  23 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  24 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28 import scala.concurrent.Future;
  29
  30 /**
  31  * Proxy class for holding required state to lazily instantiate a listener registration with an
  32  * asynchronously-discovered actor.
  33  *
  34  * @param <T> listener type
  35  */
  36 final class DataTreeChangeListenerProxy<T extends DOMDataTreeChangeListener> extends AbstractListenerRegistration<T> {
  37     private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerProxy.class);
  38     private final ActorRef dataChangeListenerActor;
  39     private final ActorContext actorContext;
  40
  41     @GuardedBy("this")
  42     private ActorSelection listenerRegistrationActor;
  43
  44     DataTreeChangeListenerProxy(final ActorContext actorContext, final T listener) {
  45         super(listener);
  46         this.actorContext = Preconditions.checkNotNull(actorContext);
  47         this.dataChangeListenerActor = actorContext.getActorSystem().actorOf(
  48                 DataTreeChangeListenerActor.props(getInstance())
  49                     .withDispatcher(actorContext.getNotificationDispatcherPath()));
  50     }
  51
  52     @Override
  53     protected synchronized void removeRegistration() {
  54         if (listenerRegistrationActor != null) {
  55             listenerRegistrationActor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), ActorRef.noSender());
  56             listenerRegistrationActor = null;
  57         }
  58
  59         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  60     }
  61
  62     void init(final String shardName, final YangInstanceIdentifier treeId) {
  63         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
  64         findFuture.onComplete(new OnComplete<ActorRef>() {
  65             @Override
  66             public void onComplete(final Throwable failure, final ActorRef shard) {
  67                 if (failure instanceof LocalShardNotFoundException) {
  68                     LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} "
  69                             + "cannot be registered", shardName, getInstance(), treeId);
  70                 } else if (failure != null) {
  71                     LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} "
  72                             + "cannot be registered: {}", shardName, getInstance(), treeId, failure);
  73                 } else {
  74                     doRegistration(shard, treeId);
  75                 }
  76             }
  77         }, actorContext.getClientDispatcher());
  78     }
  79
  80     private void setListenerRegistrationActor(final ActorSelection actor) {
  81         if (actor == null) {
  82             LOG.debug("Ignoring null actor on {}", this);
  83             return;
  84         }
  85
  86         synchronized (this) {
  87             if (!isClosed()) {
  88                 this.listenerRegistrationActor = actor;
  89                 return;
  90             }
  91         }
  92
  93         // This registration has already been closed, notify the actor
  94         actor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), null);
  95     }
  96
  97     private void doRegistration(final ActorRef shard, final YangInstanceIdentifier path) {
  98
  99         Future<Object> future = actorContext.executeOperationAsync(shard,
 100                 new RegisterDataTreeChangeListener(path, dataChangeListenerActor,
 101                         getInstance() instanceof ClusteredDOMDataTreeChangeListener),
 102                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 103
 104         future.onComplete(new OnComplete<Object>() {
 105             @Override
 106             public void onComplete(final Throwable failure, final Object result) {
 107                 if (failure != null) {
 108                     LOG.error("Failed to register DataTreeChangeListener {} at path {}",
 109                             getInstance(), path.toString(), failure);
 110                 } else {
 111                     RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
 112                     setListenerRegistrationActor(actorContext.actorSelection(
 113                             reply.getListenerRegistrationPath()));
 114                 }
 115             }
 116         }, actorContext.getClientDispatcher());
 117     }
 118
 119     @VisibleForTesting
 120     synchronized ActorSelection getListenerRegistrationActor() {
 121         return listenerRegistrationActor;
 122     }
 123
 124     @VisibleForTesting
 125     ActorRef getDataChangeListenerActor() {
 126         return dataChangeListenerActor;
 127     }
 128 }