opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataChangeListenerRegistrationProxy.java

   1 /*
   2  * Copyright (c) 2014 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
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorRef;
  12 import akka.actor.ActorSelection;
  13 import akka.actor.PoisonPill;
  14 import akka.dispatch.OnComplete;
  15 import com.google.common.annotations.VisibleForTesting;
  16 import com.google.common.base.Preconditions;
  17 import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
  18 import org.opendaylight.controller.cluster.datastore.messages.CloseDataChangeListenerRegistration;
  19 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  20 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  21 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  22 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker;
  23 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  24 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  25 import org.opendaylight.controller.md.sal.dom.api.ClusteredDOMDataChangeListener;
  26 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  28 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31 import scala.concurrent.Future;
  32
  33 /**
  34  * ListenerRegistrationProxy acts as a proxy for a ListenerRegistration that was done on a remote shard
  35  * <p>
  36  * Registering a DataChangeListener on the Data Store creates a new instance of the ListenerRegistrationProxy
  37  * The ListenerRegistrationProxy talks to a remote ListenerRegistration actor.
  38  * </p>
  39  */
  40 @SuppressWarnings("rawtypes")
  41 public class DataChangeListenerRegistrationProxy implements ListenerRegistration {
  42
  43     private static final Logger LOG = LoggerFactory.getLogger(DataChangeListenerRegistrationProxy.class);
  44
  45     private final AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener;
  46     private final String shardName;
  47     private final ActorContext actorContext;
  48     private ActorRef dataChangeListenerActor;
  49     private volatile ActorSelection listenerRegistrationActor;
  50     private boolean closed = false;
  51
  52     public <L extends AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>
  53                                                               DataChangeListenerRegistrationProxy (
  54             String shardName, ActorContext actorContext, L listener) {
  55         this.shardName = Preconditions.checkNotNull(shardName);
  56         this.actorContext = Preconditions.checkNotNull(actorContext);
  57         this.listener = Preconditions.checkNotNull(listener);
  58     }
  59
  60     @VisibleForTesting
  61     ActorSelection getListenerRegistrationActor() {
  62         return listenerRegistrationActor;
  63     }
  64
  65     @VisibleForTesting
  66     ActorRef getDataChangeListenerActor() {
  67         return dataChangeListenerActor;
  68     }
  69
  70     @Override
  71     public Object getInstance() {
  72         return listener;
  73     }
  74
  75     private void setListenerRegistrationActor(ActorSelection listenerRegistrationActor) {
  76         if(listenerRegistrationActor == null) {
  77             return;
  78         }
  79
  80         boolean sendCloseMessage = false;
  81         synchronized(this) {
  82             if(closed) {
  83                 sendCloseMessage = true;
  84             } else {
  85                 this.listenerRegistrationActor = listenerRegistrationActor;
  86             }
  87         }
  88
  89         if(sendCloseMessage) {
  90             listenerRegistrationActor.tell(CloseDataChangeListenerRegistration.INSTANCE, null);
  91         }
  92     }
  93
  94     public void init(final YangInstanceIdentifier path, final AsyncDataBroker.DataChangeScope scope) {
  95
  96         dataChangeListenerActor = actorContext.getActorSystem().actorOf(
  97                 DataChangeListener.props(listener, path).withDispatcher(actorContext.getNotificationDispatcherPath()));
  98
  99         Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
 100         findFuture.onComplete(new OnComplete<ActorRef>() {
 101             @Override
 102             public void onComplete(Throwable failure, ActorRef shard) {
 103                 if(failure instanceof LocalShardNotFoundException) {
 104                     LOG.debug("No local shard found for {} - DataChangeListener {} at path {} " +
 105                             "cannot be registered", shardName, listener, path);
 106                 } else if(failure != null) {
 107                     LOG.error("Failed to find local shard {} - DataChangeListener {} at path {} " +
 108                             "cannot be registered: {}", shardName, listener, path, failure);
 109                 } else {
 110                     doRegistration(shard, path, scope);
 111                 }
 112             }
 113         }, actorContext.getClientDispatcher());
 114     }
 115
 116     private void doRegistration(ActorRef shard, final YangInstanceIdentifier path,
 117             DataChangeScope scope) {
 118
 119         Future<Object> future = actorContext.executeOperationAsync(shard,
 120                 new RegisterChangeListener(path, dataChangeListenerActor, scope,
 121                     listener instanceof ClusteredDOMDataChangeListener),
 122                 actorContext.getDatastoreContext().getShardInitializationTimeout());
 123
 124         future.onComplete(new OnComplete<Object>(){
 125             @Override
 126             public void onComplete(Throwable failure, Object result) {
 127                 if(failure != null) {
 128                     LOG.error("Failed to register DataChangeListener {} at path {}",
 129                             listener, path.toString(), failure);
 130                 } else {
 131                     RegisterChangeListenerReply reply = (RegisterChangeListenerReply) result;
 132                     setListenerRegistrationActor(actorContext.actorSelection(
 133                             reply.getListenerRegistrationPath()));
 134                 }
 135             }
 136         }, actorContext.getClientDispatcher());
 137     }
 138
 139     @Override
 140     public void close() {
 141
 142         boolean sendCloseMessage;
 143         synchronized(this) {
 144             sendCloseMessage = !closed && listenerRegistrationActor != null;
 145             closed = true;
 146         }
 147
 148         if(sendCloseMessage) {
 149             listenerRegistrationActor.tell(CloseDataChangeListenerRegistration.INSTANCE, ActorRef.noSender());
 150             listenerRegistrationActor = null;
 151         }
 152
 153         if(dataChangeListenerActor != null) {
 154             dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
 155             dataChangeListenerActor = null;
 156         }
 157     }
 158 }