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 static java.util.Objects.requireNonNull;
  11
  12 import akka.actor.ActorRef;
  13 import akka.actor.ActorSelection;
  14 import akka.actor.PoisonPill;
  15 import akka.dispatch.OnComplete;
  16 import com.google.common.annotations.VisibleForTesting;
  17 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  18 import org.checkerframework.checker.lock.qual.GuardedBy;
  19 import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
  20 import org.opendaylight.controller.cluster.datastore.messages.CloseDataTreeNotificationListenerRegistration;
  21 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  22 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeNotificationListenerReply;
  23 import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
  24 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  26 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30 import scala.concurrent.Future;
  31
  32 /**
  33  * Proxy class for holding required state to lazily instantiate a listener registration with an
  34  * asynchronously-discovered actor.
  35  *
  36  * @param <T> listener type
  37  */
  38 final class DataTreeChangeListenerProxy<T extends DOMDataTreeChangeListener> extends AbstractListenerRegistration<T> {
  39     private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerProxy.class);
  40     private final ActorRef dataChangeListenerActor;
  41     private final ActorUtils actorUtils;
  42     private final YangInstanceIdentifier registeredPath;
  43
  44     @GuardedBy("this")
  45     private ActorSelection listenerRegistrationActor;
  46
  47     DataTreeChangeListenerProxy(final ActorUtils actorUtils, final T listener,
  48             final YangInstanceIdentifier registeredPath) {
  49         super(listener);
  50         this.actorUtils = requireNonNull(actorUtils);
  51         this.registeredPath = requireNonNull(registeredPath);
  52         this.dataChangeListenerActor = actorUtils.getActorSystem().actorOf(
  53                 DataTreeChangeListenerActor.props(getInstance(), registeredPath)
  54                     .withDispatcher(actorUtils.getNotificationDispatcherPath()));
  55
  56         LOG.debug("{}: Created actor {} for DTCL {}", actorUtils.getDatastoreContext().getLogicalStoreType(),
  57                 dataChangeListenerActor, listener);
  58     }
  59
  60     @Override
  61     protected synchronized void removeRegistration() {
  62         if (listenerRegistrationActor != null) {
  63             listenerRegistrationActor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(),
  64                     ActorRef.noSender());
  65             listenerRegistrationActor = null;
  66         }
  67
  68         dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
  69     }
  70
  71     void init(final String shardName) {
  72         Future<ActorRef> findFuture = actorUtils.findLocalShardAsync(shardName);
  73         findFuture.onComplete(new OnComplete<ActorRef>() {
  74             @Override
  75             public void onComplete(final Throwable failure, final ActorRef shard) {
  76                 if (failure instanceof LocalShardNotFoundException) {
  77                     LOG.debug("{}: No local shard found for {} - DataTreeChangeListener {} at path {} "
  78                             + "cannot be registered", logContext(), shardName, getInstance(), registeredPath);
  79                 } else if (failure != null) {
  80                     LOG.error("{}: Failed to find local shard {} - DataTreeChangeListener {} at path {} "
  81                             + "cannot be registered", logContext(), shardName, getInstance(), registeredPath,
  82                             failure);
  83                 } else {
  84                     doRegistration(shard);
  85                 }
  86             }
  87         }, actorUtils.getClientDispatcher());
  88     }
  89
  90     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
  91             justification = "https://github.com/spotbugs/spotbugs/issues/811")
  92     private void setListenerRegistrationActor(final ActorSelection actor) {
  93         if (actor == null) {
  94             LOG.debug("{}: Ignoring null actor on {}", logContext(), this);
  95             return;
  96         }
  97
  98         synchronized (this) {
  99             if (!isClosed()) {
 100                 this.listenerRegistrationActor = actor;
 101                 return;
 102             }
 103         }
 104
 105         // This registration has already been closed, notify the actor
 106         actor.tell(CloseDataTreeNotificationListenerRegistration.getInstance(), null);
 107     }
 108
 109     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
 110             justification = "https://github.com/spotbugs/spotbugs/issues/811")
 111     private void doRegistration(final ActorRef shard) {
 112
 113         Future<Object> future = actorUtils.executeOperationAsync(shard,
 114                 new RegisterDataTreeChangeListener(registeredPath, dataChangeListenerActor,
 115                         getInstance() instanceof ClusteredDOMDataTreeChangeListener),
 116                 actorUtils.getDatastoreContext().getShardInitializationTimeout());
 117
 118         future.onComplete(new OnComplete<Object>() {
 119             @Override
 120             public void onComplete(final Throwable failure, final Object result) {
 121                 if (failure != null) {
 122                     LOG.error("{}: Failed to register DataTreeChangeListener {} at path {}", logContext(),
 123                             getInstance(), registeredPath, failure);
 124                 } else {
 125                     RegisterDataTreeNotificationListenerReply reply = (RegisterDataTreeNotificationListenerReply)result;
 126                     setListenerRegistrationActor(actorUtils.actorSelection(
 127                             reply.getListenerRegistrationPath()));
 128                 }
 129             }
 130         }, actorUtils.getClientDispatcher());
 131     }
 132
 133     @VisibleForTesting
 134     synchronized ActorSelection getListenerRegistrationActor() {
 135         return listenerRegistrationActor;
 136     }
 137
 138     @VisibleForTesting
 139     ActorRef getDataChangeListenerActor() {
 140         return dataChangeListenerActor;
 141     }
 142
 143     private String logContext() {
 144         return actorUtils.getDatastoreContext().getLogicalStoreType().toString();
 145     }
 146 }