opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/DataChangeListenerSupport.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 akka.actor.ActorRef;
  11 import akka.actor.ActorSelection;
  12 import com.google.common.base.Optional;
  13 import java.util.ArrayList;
  14 import java.util.List;
  15 import java.util.Map.Entry;
  16 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  17 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  18 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  19 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  20 import org.opendaylight.controller.md.sal.dom.store.impl.DataChangeListenerRegistration;
  21 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  22 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  23 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 final class DataChangeListenerSupport extends LeaderLocalDelegateFactory<RegisterChangeListener,
  29         DataChangeListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>,
  30         Optional<DataTreeCandidate>> {
  31     private static final Logger LOG = LoggerFactory.getLogger(DataChangeListenerSupport.class);
  32     private final List<DelayedListenerRegistration> delayedListenerRegistrations = new ArrayList<>();
  33     private final List<ActorSelection> dataChangeListeners =  new ArrayList<>();
  34     private final List<DelayedListenerRegistration> delayedRegisterOnAllListeners = new ArrayList<>();
  35
  36     DataChangeListenerSupport(final Shard shard) {
  37         super(shard);
  38     }
  39
  40     @Override
  41     void onLeadershipChange(final boolean isLeader, boolean hasLeader) {
  42         LOG.debug("onLeadershipChange, isLeader: {}, hasLeader : {}", isLeader, hasLeader);
  43
  44         for (ActorSelection dataChangeListener : dataChangeListeners) {
  45             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
  46         }
  47
  48         if(hasLeader) {
  49             for (DelayedListenerRegistration reg : delayedRegisterOnAllListeners) {
  50                 registerDelayedListeners(reg);
  51             }
  52             delayedRegisterOnAllListeners.clear();
  53         }
  54
  55         if (isLeader) {
  56             for (DelayedListenerRegistration reg: delayedListenerRegistrations) {
  57                 registerDelayedListeners(reg);
  58             }
  59
  60             delayedListenerRegistrations.clear();
  61         }
  62     }
  63
  64     private void registerDelayedListeners(DelayedListenerRegistration reg) {
  65         if(!reg.isClosed()) {
  66             final Entry<DataChangeListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>,
  67                             Optional<DataTreeCandidate>> res = createDelegate(reg.getRegisterChangeListener());
  68             reg.setDelegate(res.getKey());
  69             getShard().getDataStore().notifyOfInitialData(res.getKey(), res.getValue());
  70         }
  71     }
  72
  73     @Override
  74     void onMessage(final RegisterChangeListener message, final boolean isLeader, boolean hasLeader) {
  75
  76         LOG.debug("{}: registerDataChangeListener for {}, isLeader: {}, hasLeader : {}",
  77             persistenceId(), message.getPath(), isLeader, hasLeader);
  78
  79         final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
  80                                                      NormalizedNode<?, ?>>> registration;
  81         if ((hasLeader && message.isRegisterOnAllInstances()) || isLeader) {
  82             final Entry<DataChangeListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>,
  83                     Optional<DataTreeCandidate>> res = createDelegate(message);
  84             registration = res.getKey();
  85
  86             getShard().getDataStore().notifyOfInitialData(res.getKey(), res.getValue());
  87         } else {
  88             LOG.debug("{}: Shard is not the leader - delaying registration", persistenceId());
  89
  90             DelayedListenerRegistration delayedReg = new DelayedListenerRegistration(message);
  91             if(message.isRegisterOnAllInstances()) {
  92                 delayedRegisterOnAllListeners.add(delayedReg);
  93             } else {
  94                 delayedListenerRegistrations.add(delayedReg);
  95             }
  96             registration = delayedReg;
  97         }
  98
  99         ActorRef listenerRegistration = createActor(DataChangeListenerRegistrationActor.props(registration));
 100
 101         LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 102                 persistenceId(), listenerRegistration.path());
 103
 104         tellSender(new RegisterChangeListenerReply(listenerRegistration));
 105     }
 106
 107     @Override
 108     Entry<DataChangeListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>,
 109             Optional<DataTreeCandidate>> createDelegate(final RegisterChangeListener message) {
 110         ActorSelection dataChangeListenerPath = selectActor(message.getDataChangeListenerPath());
 111
 112         // Notify the listener if notifications should be enabled or not
 113         // If this shard is the leader then it will enable notifications else
 114         // it will not
 115         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 116
 117         // Now store a reference to the data change listener so it can be notified
 118         // at a later point if notifications should be enabled or disabled
 119         if(!message.isRegisterOnAllInstances()) {
 120             dataChangeListeners.add(dataChangeListenerPath);
 121         }
 122
 123         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 124                 new DataChangeListenerProxy(dataChangeListenerPath);
 125
 126         LOG.debug("{}: Registering for path {}", persistenceId(), message.getPath());
 127
 128         return getShard().getDataStore().registerChangeListener(message.getPath(), listener,
 129                 message.getScope());
 130     }
 131 }