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