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

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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.entityownership;
   9
  10 import akka.actor.ActorContext;
  11 import akka.actor.ActorRef;
  12 import akka.actor.PoisonPill;
  13 import com.google.common.collect.HashMultimap;
  14 import com.google.common.collect.Multimap;
  15 import java.util.Arrays;
  16 import java.util.Collection;
  17 import java.util.IdentityHashMap;
  18 import java.util.Map;
  19 import org.opendaylight.controller.cluster.datastore.entityownership.messages.EntityOwnershipChanged;
  20 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  21 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 /**
  26  * Manages EntityOwnershipListener registrations and notifications for the EntityOwnershipShard.
  27  *
  28  * @author Thomas Pantelis
  29  */
  30 class EntityOwnershipListenerSupport {
  31     private static final Logger LOG = LoggerFactory.getLogger(EntityOwnershipListenerSupport.class);
  32
  33     private final ActorContext actorContext;
  34     private final Map<EntityOwnershipListener, ListenerActorRefEntry> listenerActorMap = new IdentityHashMap<>();
  35     private final Multimap<Entity, EntityOwnershipListener> entityListenerMap = HashMultimap.create();
  36     private final Multimap<String, EntityOwnershipListener> entityTypeListenerMap = HashMultimap.create();
  37
  38     EntityOwnershipListenerSupport(ActorContext actorContext) {
  39         this.actorContext = actorContext;
  40     }
  41
  42     void addEntityOwnershipListener(Entity entity, EntityOwnershipListener listener) {
  43         LOG.debug("Adding EntityOwnershipListener {} for {}", listener, entity);
  44
  45         addListener(listener, entity, entityListenerMap);
  46     }
  47
  48     void addEntityOwnershipListener(String entityType, EntityOwnershipListener listener) {
  49         LOG.debug("Adding EntityOwnershipListener {} for entity type {}", listener, entityType);
  50
  51         addListener(listener, entityType, entityTypeListenerMap);
  52     }
  53
  54     void removeEntityOwnershipListener(Entity entity, EntityOwnershipListener listener) {
  55         LOG.debug("Removing EntityOwnershipListener {} for {}", listener, entity);
  56
  57         removeListener(listener, entity, entityListenerMap);
  58     }
  59
  60     void removeEntityOwnershipListener(String entityType, EntityOwnershipListener listener) {
  61         LOG.debug("Removing EntityOwnershipListener {} for entity type {}", listener, entityType);
  62
  63         removeListener(listener, entityType, entityTypeListenerMap);
  64     }
  65
  66     void notifyEntityOwnershipListeners(Entity entity, boolean wasOwner, boolean isOwner) {
  67         notifyListeners(entity, entity, wasOwner, isOwner, entityListenerMap);
  68         notifyListeners(entity, entity.getType(), wasOwner, isOwner, entityTypeListenerMap);
  69     }
  70
  71     void notifyEntityOwnershipListener(Entity entity, boolean wasOwner, boolean isOwner,
  72             EntityOwnershipListener listener) {
  73         notifyListeners(entity, wasOwner, isOwner, Arrays.asList(listener));
  74     }
  75
  76     private <T> void notifyListeners(Entity entity, T mapKey, boolean wasOwner, boolean isOwner,
  77             Multimap<T, EntityOwnershipListener> listenerMap) {
  78         Collection<EntityOwnershipListener> listeners = listenerMap.get(mapKey);
  79         if(!listeners.isEmpty()) {
  80             notifyListeners(entity, wasOwner, isOwner, listeners);
  81         }
  82     }
  83
  84     private void notifyListeners(Entity entity, boolean wasOwner, boolean isOwner,
  85             Collection<EntityOwnershipListener> listeners) {
  86         EntityOwnershipChanged changed = new EntityOwnershipChanged(entity, wasOwner, isOwner);
  87         for(EntityOwnershipListener listener: listeners) {
  88             ActorRef listenerActor = listenerActorFor(listener);
  89
  90             LOG.debug("Notifying EntityOwnershipListenerActor {} with {}", listenerActor, changed);
  91
  92             listenerActor.tell(changed, ActorRef.noSender());
  93         }
  94     }
  95
  96     private <T> void addListener(EntityOwnershipListener listener, T mapKey,
  97             Multimap<T, EntityOwnershipListener> toListenerMap) {
  98         if(toListenerMap.put(mapKey, listener)) {
  99             ListenerActorRefEntry listenerEntry = listenerActorMap.get(listener);
 100             if(listenerEntry == null) {
 101                 listenerActorMap.put(listener, new ListenerActorRefEntry());
 102             } else {
 103                 listenerEntry.referenceCount++;
 104             }
 105         }
 106     }
 107
 108     private <T> void removeListener(EntityOwnershipListener listener, T mapKey,
 109             Multimap<T, EntityOwnershipListener> fromListenerMap) {
 110         if(fromListenerMap.remove(mapKey, listener)) {
 111             ListenerActorRefEntry listenerEntry = listenerActorMap.get(listener);
 112
 113             LOG.debug("Found {}", listenerEntry);
 114
 115             listenerEntry.referenceCount--;
 116             if(listenerEntry.referenceCount <= 0) {
 117                 listenerActorMap.remove(listener);
 118
 119                 if(listenerEntry.actorRef != null) {
 120                     LOG.debug("Killing EntityOwnershipListenerActor {}", listenerEntry.actorRef);
 121                     listenerEntry.actorRef.tell(PoisonPill.getInstance(), ActorRef.noSender());
 122                 }
 123             }
 124         }
 125     }
 126
 127     private ActorRef listenerActorFor(EntityOwnershipListener listener) {
 128         return listenerActorMap.get(listener).actorFor(listener);
 129     }
 130
 131     private class ListenerActorRefEntry {
 132         ActorRef actorRef;
 133         int referenceCount = 1;
 134
 135         ActorRef actorFor(EntityOwnershipListener listener) {
 136             if(actorRef == null) {
 137                 actorRef = actorContext.actorOf(EntityOwnershipListenerActor.props(listener));
 138
 139                 LOG.debug("Created EntityOwnershipListenerActor {} for listener {}", actorRef, listener);
 140             }
 141
 142             return actorRef;
 143         }
 144
 145         @Override
 146         public String toString() {
 147             return "ListenerActorRefEntry [actorRef=" + actorRef + ", referenceCount=" + referenceCount + "]";
 148         }
 149     }
 150 }