Simplify DTCL registration support classes
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / DataTreeChangeListenerSupport.java
index a3ed4a19c9b31de30d5c53dc569b95d6d6697566..348b2aa939efc10617a8f9544a5a738acfdd5345 100644 (file)
@@ -9,25 +9,37 @@ package org.opendaylight.controller.cluster.datastore;
 
 import akka.actor.ActorRef;
 import akka.actor.ActorSelection;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.concurrent.ConcurrentHashMap;
 import org.opendaylight.controller.cluster.datastore.actors.DataTreeNotificationListenerRegistrationActor;
+import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
-import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListenerReply;
-import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
+import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeNotificationListenerReply;
+import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
-final class DataTreeChangeListenerSupport extends AbstractDataListenerSupport<DOMDataTreeChangeListener,
-        RegisterDataTreeChangeListener> {
+final class DataTreeChangeListenerSupport extends LeaderLocalDelegateFactory<RegisterDataTreeChangeListener> {
+    private static final Logger LOG = LoggerFactory.getLogger(DataTreeChangeListenerSupport.class);
+
+    private final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>>
+            delayedDataTreeChangeListenerRegistrations = ConcurrentHashMap.newKeySet();
+    private final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>>
+            delayedListenerOnAllRegistrations = ConcurrentHashMap.newKeySet();
+    private final Collection<ActorSelection> leaderOnlyListenerActors = ConcurrentHashMap.newKeySet();
+    private final Collection<ActorSelection> allListenerActors = ConcurrentHashMap.newKeySet();
 
     DataTreeChangeListenerSupport(final Shard shard) {
         super(shard);
     }
 
-    @Override
     void doRegistration(final RegisterDataTreeChangeListener message, final ActorRef registrationActor) {
         final ActorSelection listenerActor = processListenerRegistrationMessage(message);
 
-        DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(listenerActor);
+        final DOMDataTreeChangeListener listener = new ForwardingDataTreeChangeListener(listenerActor);
 
-        log().debug("{}: Registering listenerActor {} for path {}", persistenceId(), listenerActor, message.getPath());
+        LOG.debug("{}: Registering listenerActor {} for path {}", persistenceId(), listenerActor, message.getPath());
 
         final ShardDataTree shardDataTree = getShard().getDataStore();
         shardDataTree.registerTreeChangeListener(message.getPath(),
@@ -36,13 +48,88 @@ final class DataTreeChangeListenerSupport extends AbstractDataListenerSupport<DO
                             removeListenerActor(listenerActor)), ActorRef.noSender()));
     }
 
+    Collection<ActorSelection> getListenerActors() {
+        return new ArrayList<>(allListenerActors);
+    }
+
     @Override
-    protected Object newRegistrationReplyMessage(ActorRef registrationActor) {
-        return new RegisterDataTreeChangeListenerReply(registrationActor);
+    void onLeadershipChange(final boolean isLeader, final boolean hasLeader) {
+        LOG.debug("{}: onLeadershipChange, isLeader: {}, hasLeader : {}", persistenceId(), isLeader, hasLeader);
+
+        final EnableNotification msg = new EnableNotification(isLeader, persistenceId());
+        for (ActorSelection dataChangeListener : leaderOnlyListenerActors) {
+            dataChangeListener.tell(msg, getSelf());
+        }
+
+        if (hasLeader) {
+            for (DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> reg :
+                    delayedListenerOnAllRegistrations) {
+                reg.doRegistration(this);
+            }
+
+            delayedListenerOnAllRegistrations.clear();
+        }
+
+        if (isLeader) {
+            for (DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> reg :
+                    delayedDataTreeChangeListenerRegistrations) {
+                reg.doRegistration(this);
+            }
+
+            delayedDataTreeChangeListenerRegistrations.clear();
+        }
     }
 
     @Override
-    protected String logName() {
-        return "registerTreeChangeListener";
+    void onMessage(final RegisterDataTreeChangeListener message, final boolean isLeader, final boolean hasLeader) {
+        LOG.debug("{}: onMessage {}, isLeader: {}, hasLeader: {}", persistenceId(), message, isLeader, hasLeader);
+
+        final ActorRef registrationActor = createActor(DataTreeNotificationListenerRegistrationActor.props());
+
+        if (hasLeader && message.isRegisterOnAllInstances() || isLeader) {
+            doRegistration(message, registrationActor);
+        } else {
+            LOG.debug("{}: Shard does not have a leader - delaying registration", persistenceId());
+
+            final DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener> delayedReg =
+                    new DelayedDataTreeChangeListenerRegistration<>(message, registrationActor);
+            final Collection<DelayedDataTreeChangeListenerRegistration<DOMDataTreeChangeListener>> delayedRegList;
+            if (message.isRegisterOnAllInstances()) {
+                delayedRegList = delayedListenerOnAllRegistrations;
+            } else {
+                delayedRegList = delayedDataTreeChangeListenerRegistrations;
+            }
+
+            delayedRegList.add(delayedReg);
+            registrationActor.tell(new DataTreeNotificationListenerRegistrationActor.SetRegistration(
+                    delayedReg, () -> delayedRegList.remove(delayedReg)), ActorRef.noSender());
+        }
+
+        LOG.debug("{}: sending RegisterDataTreeNotificationListenerReply, listenerRegistrationPath = {} ",
+                persistenceId(), registrationActor.path());
+
+        tellSender(new RegisterDataTreeNotificationListenerReply(registrationActor));
+    }
+
+    private ActorSelection processListenerRegistrationMessage(final RegisterDataTreeChangeListener message) {
+        final ActorSelection listenerActor = selectActor(message.getListenerActorPath());
+
+        // We have a leader so enable the listener.
+        listenerActor.tell(new EnableNotification(true, persistenceId()), getSelf());
+
+        if (!message.isRegisterOnAllInstances()) {
+            // This is a leader-only registration so store a reference to the listener actor so it can be notified
+            // at a later point if notifications should be enabled or disabled.
+            leaderOnlyListenerActors.add(listenerActor);
+        }
+
+        allListenerActors.add(listenerActor);
+
+        return listenerActor;
+    }
+
+    private void removeListenerActor(final ActorSelection listenerActor) {
+        allListenerActors.remove(listenerActor);
+        leaderOnlyListenerActors.remove(listenerActor);
     }
 }