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