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.RegisterDataTreeNotificationListenerReply;
  21 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  22 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  23 import org.opendaylight.mdsal.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         LOG.debug("{}: Created actor {} for DTCL {}", actorContext.getDatastoreContext().getLogicalStoreType(),
  55                 dataChangeListenerActor, listener);
  56     }
  57
  58     @Override
  59     protected synchronized void removeRegistration() {
  60         if (listenerRegistrationActor != null) {
  61             listenerRegistrationActor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(),
  62                     ActorRef.noSender());
  63             listenerRegistrationActor = null;
  64         }
  65
  66         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  67     }
  68
  69     void init(final String shardName) {
  70         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
  71         findFuture.onComplete(new OnComplete<ActorRef>() {
  72             @Override
  73             public void onComplete(final Throwable failure, final ActorRef shard) {
  74                 if (failure instanceof LocalShardNotFoundException) {
  75                     LOG.debug("{}: No local shard found for {} - DataTreeChangeListener {} at path {} "
  76                             + "cannot be registered", logContext(), shardName, getInstance(), registeredPath);
  77                 } else if (failure != null) {
  78                     LOG.error("{}: Failed to find local shard {} - DataTreeChangeListener {} at path {} "
  79                             + "cannot be registered: {}", logContext(), shardName, getInstance(), registeredPath,
  80                             failure);
  81                 } else {
  82                     doRegistration(shard);
  83                 }
  84             }
  85         }, actorContext.getClientDispatcher());
  86     }
  87
  88     private void setListenerRegistrationActor(final ActorSelection actor) {
  89         if (actor == null) {
  90             LOG.debug("{}: Ignoring null actor on {}", logContext(), this);
  91             return;
  92         }
  93
  94         synchronized (this) {
  95             if (!isClosed()) {
  96                 this.listenerRegistrationActor = actor;
  97                 return;
  98             }
  99         }
 100
 101         // This registration has already been closed, notify the actor
 102         actor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(), null);
 103     }
 104
 105     private void doRegistration(final ActorRef shard) {
 106
 107         Future<Object> future = actorContext.executeOperationAsync(shard,
 108                 new RegisterDataTreeChangeListener(registeredPath, dataChangeListenerActor,
 109                         getInstance() instanceof ClusteredDOMDataTreeChangeListener),
 110                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 111
 112         future.onComplete(new OnComplete<Object>() {
 113             @Override
 114             public void onComplete(final Throwable failure, final Object result) {
 115                 if (failure != null) {
 116                     LOG.error("{}: Failed to register DataTreeChangeListener {} at path {}", logContext(),
 117                             getInstance(), registeredPath, failure);
 118                 } else {
 119                     RegisterDataTreeNotificationListenerReply reply = (RegisterDataTreeNotificationListenerReply)result;
 120                     setListenerRegistrationActor(actorContext.actorSelection(
 121                             reply.getListenerRegistrationPath()));
 122                 }
 123             }
 124         }, actorContext.getClientDispatcher());
 125     }
 126
 127     @VisibleForTesting
 128     synchronized ActorSelection getListenerRegistrationActor() {
 129         return listenerRegistrationActor;
 130     }
 131
 132     @VisibleForTesting
 133     ActorRef getDataChangeListenerActor() {
 134         return dataChangeListenerActor;
 135     }
 136
 137     private String logContext() {
 138         return actorContext.getDatastoreContext().getLogicalStoreType().toString();
 139     }
 140 }