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     public 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()).withDispatcher(actorContext.getNotificationDispatcherPath()));
  49     }
  50
  51     @Override
  52     protected synchronized void removeRegistration() {
  53         if (listenerRegistrationActor != null) {
  54             listenerRegistrationActor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), ActorRef.noSender());
  55             listenerRegistrationActor = null;
  56         }
  57
  58         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  59     }
  60
  61     void init(final String shardName, final YangInstanceIdentifier treeId) {
  62         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
  63         findFuture.onComplete(new OnComplete<ActorRef>() {
  64             @Override
  65             public void onComplete(final Throwable failure, final ActorRef shard) {
  66                 if (failure instanceof LocalShardNotFoundException) {
  67                     LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} " +
  68                             "cannot be registered", shardName, getInstance(), treeId);
  69                 } else if (failure != null) {
  70                     LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} " +
  71                             "cannot be registered: {}", shardName, getInstance(), treeId, failure);
  72                 } else {
  73                     doRegistration(shard, treeId);
  74                 }
  75             }
  76         }, actorContext.getClientDispatcher());
  77     }
  78
  79     private void setListenerRegistrationActor(final ActorSelection actor) {
  80         if (actor == null) {
  81             LOG.debug("Ignoring null actor on {}", this);
  82             return;
  83         }
  84
  85         synchronized (this) {
  86             if (!isClosed()) {
  87                 this.listenerRegistrationActor = actor;
  88                 return;
  89             }
  90         }
  91
  92         // This registration has already been closed, notify the actor
  93         actor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), null);
  94     }
  95
  96     private void doRegistration(final ActorRef shard, final YangInstanceIdentifier path) {
  97
  98         Future<Object> future = actorContext.executeOperationAsync(shard,
  99                 new RegisterDataTreeChangeListener(path, dataChangeListenerActor,
 100                         getInstance() instanceof ClusteredDOMDataTreeChangeListener),
 101                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 102
 103         future.onComplete(new OnComplete<Object>(){
 104             @Override
 105             public void onComplete(final Throwable failure, final Object result) {
 106                 if (failure != null) {
 107                     LOG.error("Failed to register DataTreeChangeListener {} at path {}",
 108                             getInstance(), path.toString(), failure);
 109                 } else {
 110                     RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
 111                     setListenerRegistrationActor(actorContext.actorSelection(
 112                             reply.getListenerRegistrationPath()));
 113                 }
 114             }
 115         }, actorContext.getClientDispatcher());
 116     }
 117
 118     @VisibleForTesting
 119     ActorSelection getListenerRegistrationActor() {
 120         return listenerRegistrationActor;
 121     }
 122
 123     @VisibleForTesting
 124     ActorRef getDataChangeListenerActor() {
 125         return dataChangeListenerActor;
 126     }
 127 }