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