BUG-2673: make CDS implement DOMDataTreeChangeListener

[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / DataTreeChangeListenerProxy.java

diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataTreeChangeListenerProxy.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataTreeChangeListenerProxy.java
new file mode 100644 (file)
index 0000000..124724b
--- /dev/null
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataTreeChangeListenerProxy.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.datastore;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSelection;
+import akka.actor.PoisonPill;
+import akka.dispatch.OnComplete;
+import com.google.common.base.Preconditions;
+import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
+import org.opendaylight.controller.cluster.datastore.messages.CloseDataTreeChangeListenerRegistration;
+import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
+import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
+import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
+import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import scala.concurrent.Future;
+
+/**
+ * Proxy class for holding required state to lazily instantiate a listener registration with an
+ * asynchronously-discovered actor.
+ *
+ * @param <T> listener type
+ */
+final class DataTreeChangeListenerProxy<T extends DOMDataTreeChangeListener> extends AbstractListenerRegistration<T> {
+    private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerProxy.class);
+    private final ActorRef dataChangeListenerActor;
+    private final ActorContext actorContext;
+
+    @GuardedBy("this")
+    private ActorSelection listenerRegistrationActor;
+
+    public DataTreeChangeListenerProxy(final ActorContext actorContext, final T listener) {
+        super(listener);
+        this.actorContext = Preconditions.checkNotNull(actorContext);
+        this.dataChangeListenerActor = actorContext.getActorSystem().actorOf(
+            DataTreeChangeListenerActor.props(getInstance()).withDispatcher(actorContext.getNotificationDispatcherPath()));
+    }
+
+    @Override
+    protected synchronized void removeRegistration() {
+        if (listenerRegistrationActor != null) {
+            listenerRegistrationActor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), ActorRef.noSender());
+            listenerRegistrationActor = null;
+        }
+
+        dataChangeListenerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
+    }
+
+    void init(final String shardName, final YangInstanceIdentifier treeId) {
+        Future<ActorRef> findFuture = actorContext.findLocalShardAsync(shardName);
+        findFuture.onComplete(new OnComplete<ActorRef>() {
+            @Override
+            public void onComplete(final Throwable failure, final ActorRef shard) {
+                if (failure instanceof LocalShardNotFoundException) {
+                    LOG.debug("No local shard found for {} - DataTreeChangeListener {} at path {} " +
+                            "cannot be registered", shardName, getInstance(), treeId);
+                } else if (failure != null) {
+                    LOG.error("Failed to find local shard {} - DataTreeChangeListener {} at path {} " +
+                            "cannot be registered: {}", shardName, getInstance(), treeId, failure);
+                } else {
+                    doRegistration(shard, treeId);
+                }
+            }
+        }, actorContext.getClientDispatcher());
+    }
+
+    private void setListenerRegistrationActor(final ActorSelection actor) {
+        if (actor == null) {
+            LOG.debug("Ignoring null actor on {}", this);
+            return;
+        }
+
+        synchronized (this) {
+            if (!isClosed()) {
+                this.listenerRegistrationActor = actor;
+                return;
+            }
+        }
+
+        // This registration has already been closed, notify the actor
+        actor.tell(CloseDataTreeChangeListenerRegistration.getInstance(), null);
+    }
+
+    private void doRegistration(final ActorRef shard, final YangInstanceIdentifier path) {
+
+        Future<Object> future = actorContext.executeOperationAsync(shard,
+                new RegisterDataTreeChangeListener(path, dataChangeListenerActor),
+                actorContext.getDatastoreContext().getShardInitializationTimeout());
+
+        future.onComplete(new OnComplete<Object>(){
+            @Override
+            public void onComplete(final Throwable failure, final Object result) {
+                if (failure != null) {
+                    LOG.error("Failed to register DataTreeChangeListener {} at path {}",
+                            getInstance(), path.toString(), failure);
+                } else {
+                    RegisterDataTreeChangeListenerReply reply = (RegisterDataTreeChangeListenerReply) result;
+                    setListenerRegistrationActor(actorContext.actorSelection(
+                            reply.getListenerRegistrationPath().path()));
+                }
+            }
+        }, actorContext.getClientDispatcher());
+    }
+}