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.CloseDataTreeNotificationListenerRegistration;
  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     private final YangInstanceIdentifier registeredPath;
  41
  42     @GuardedBy("this")
  43     private ActorSelection listenerRegistrationActor;
  44
  45     DataTreeChangeListenerProxy(final ActorContext actorContext, final T listener,
  46             final YangInstanceIdentifier registeredPath) {
  47         super(listener);
  48         this.actorContext = Preconditions.checkNotNull(actorContext);
  49         this.registeredPath = Preconditions.checkNotNull(registeredPath);
  50         this.dataChangeListenerActor = actorContext.getActorSystem().actorOf(
  51                 DataTreeChangeListenerActor.props(getInstance(), registeredPath)
  52                     .withDispatcher(actorContext.getNotificationDispatcherPath()));
  53     }
  54
  55     @Override
  56     protected synchronized void removeRegistration() {
  57         if (listenerRegistrationActor != null) {
  58             listenerRegistrationActor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(),
  59                     ActorRef.noSender());
  60             listenerRegistrationActor = null;
  61         }
  62
  63         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  64     }
  65
  66     void init(final String shardName) {
  67         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
  68         findFuture.onComplete(new OnComplete<ActorRef>() {
  69             @Override
  70             public void onComplete(final Throwable failure, final ActorRef shard) {
  71                 if (failure instanceof LocalShardNotFoundException) {
  72                     LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} "
  73                             + "cannot be registered", shardName, getInstance(), registeredPath);
  74                 } else if (failure != null) {
  75                     LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} "
  76                             + "cannot be registered: {}", shardName, getInstance(), registeredPath, failure);
  77                 } else {
  78                     doRegistration(shard);
  79                 }
  80             }
  81         }, actorContext.getClientDispatcher());
  82     }
  83
  84     private void setListenerRegistrationActor(final ActorSelection actor) {
  85         if (actor == null) {
  86             LOG.debug("Ignoring null actor on {}", this);
  87             return;
  88         }
  89
  90         synchronized (this) {
  91             if (!isClosed()) {
  92                 this.listenerRegistrationActor = actor;
  93                 return;
  94             }
  95         }
  96
  97         // This registration has already been closed, notify the actor
  98         actor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(), null);
  99     }
 100
 101     private void doRegistration(final ActorRef shard) {
 102
 103         Future<Object> future = actorContext.executeOperationAsync(shard,
 104                 new RegisterDataTreeChangeListener(registeredPath, dataChangeListenerActor,
 105                         getInstance() instanceof ClusteredDOMDataTreeChangeListener),
 106                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 107
 108         future.onComplete(new OnComplete<Object>() {
 109             @Override
 110             public void onComplete(final Throwable failure, final Object result) {
 111                 if (failure != null) {
 112                     LOG.error("Failed to register DataTreeChangeListener {} at path {}",
 113                             getInstance(), registeredPath, failure);
 114                 } else {
 115                     RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
 116                     setListenerRegistrationActor(actorContext.actorSelection(
 117                             reply.getListenerRegistrationPath()));
 118                 }
 119             }
 120         }, actorContext.getClientDispatcher());
 121     }
 122
 123     @VisibleForTesting
 124     synchronized ActorSelection getListenerRegistrationActor() {
 125         return listenerRegistrationActor;
 126     }
 127
 128     @VisibleForTesting
 129     ActorRef getDataChangeListenerActor() {
 130         return dataChangeListenerActor;
 131     }
 132 }