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.Collection;
  16 import java.util.Collections;
  17 import java.util.HashSet;
  18 import java.util.IdentityHashMap;
  19 import java.util.Map;
  20 import java.util.Set;
  21 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  22 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipChange;
  23 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 /**
  28  * Manages EntityOwnershipListener registrations and notifications for the EntityOwnershipShard.
  29  *
  30  * @author Thomas Pantelis
  31  */
  32 class EntityOwnershipListenerSupport {
  33     private static final Logger LOG = LoggerFactory.getLogger(EntityOwnershipListenerSupport.class);
  34
  35     private final String logId;
  36     private final ActorContext actorContext;
  37     private final Map<EntityOwnershipListener, ListenerActorRefEntry> listenerActorMap = new IdentityHashMap<>();
  38     private final Set<Entity> entitiesWithCandidateSet = new HashSet<>();
  39     private final Multimap<String, EntityOwnershipListener> entityTypeListenerMap = HashMultimap.create();
  40     private volatile boolean inJeopardy = false;
  41
  42     EntityOwnershipListenerSupport(ActorContext actorContext, String logId) {
  43         this.actorContext = actorContext;
  44         this.logId = logId;
  45     }
  46
  47     String getLogId() {
  48         return logId;
  49     }
  50
  51     /**
  52      * Set the in-jeopardy flag and indicate its previous state.
  53      *
  54      * @param inJeopardy new value of the in-jeopardy flag
  55      * @return Previous value of the flag.
  56      */
  57     boolean setInJeopardy(final boolean inJeopardy) {
  58         final boolean wasInJeopardy = this.inJeopardy;
  59         this.inJeopardy = inJeopardy;
  60         return wasInJeopardy;
  61     }
  62
  63     boolean hasCandidateForEntity(Entity entity) {
  64         return entitiesWithCandidateSet.contains(entity);
  65     }
  66
  67     void setHasCandidateForEntity(Entity entity) {
  68         entitiesWithCandidateSet.add(entity);
  69     }
  70
  71     void unsetHasCandidateForEntity(Entity entity) {
  72         entitiesWithCandidateSet.remove(entity);
  73     }
  74
  75     void addEntityOwnershipListener(String entityType, EntityOwnershipListener listener) {
  76         LOG.debug("{}: Adding EntityOwnershipListener {} for entity type {}", logId, listener, entityType);
  77
  78         addListener(listener, entityType);
  79     }
  80
  81     void removeEntityOwnershipListener(String entityType, EntityOwnershipListener listener) {
  82         LOG.debug("{}: Removing EntityOwnershipListener {} for entity type {}", logId, listener, entityType);
  83
  84         removeListener(listener, entityType);
  85     }
  86
  87     void notifyEntityOwnershipListeners(Entity entity, boolean wasOwner, boolean isOwner, boolean hasOwner) {
  88         notifyListeners(entity, entity.getType(), wasOwner, isOwner, hasOwner);
  89     }
  90
  91     void notifyEntityOwnershipListener(Entity entity, boolean wasOwner, boolean isOwner, boolean hasOwner,
  92             EntityOwnershipListener listener) {
  93         notifyListeners(entity, wasOwner, isOwner, hasOwner, Collections.singleton(listener));
  94     }
  95
  96     private void notifyListeners(Entity entity, String mapKey, boolean wasOwner, boolean isOwner, boolean hasOwner) {
  97         Collection<EntityOwnershipListener> listeners = entityTypeListenerMap.get(mapKey);
  98         if(!listeners.isEmpty()) {
  99             notifyListeners(entity, wasOwner, isOwner, hasOwner, listeners);
 100         }
 101     }
 102
 103     private void notifyListeners(Entity entity, boolean wasOwner, boolean isOwner, boolean hasOwner,
 104             Collection<EntityOwnershipListener> listeners) {
 105         EntityOwnershipChange changed = new EntityOwnershipChange(entity, wasOwner, isOwner, hasOwner, inJeopardy);
 106         for(EntityOwnershipListener listener: listeners) {
 107             ActorRef listenerActor = listenerActorFor(listener);
 108
 109             LOG.debug("{}: Notifying EntityOwnershipListenerActor {} with {}", logId, listenerActor, changed);
 110
 111             listenerActor.tell(changed, ActorRef.noSender());
 112         }
 113     }
 114
 115     private void addListener(EntityOwnershipListener listener, String mapKey) {
 116         if (entityTypeListenerMap.put(mapKey, listener)) {
 117             ListenerActorRefEntry listenerEntry = listenerActorMap.get(listener);
 118             if(listenerEntry == null) {
 119                 listenerActorMap.put(listener, new ListenerActorRefEntry());
 120             } else {
 121                 listenerEntry.referenceCount++;
 122             }
 123         }
 124     }
 125
 126     private void removeListener(EntityOwnershipListener listener, String mapKey) {
 127         if (entityTypeListenerMap.remove(mapKey, listener)) {
 128             ListenerActorRefEntry listenerEntry = listenerActorMap.get(listener);
 129
 130             LOG.debug("{}: Found {}", logId, listenerEntry);
 131
 132             listenerEntry.referenceCount--;
 133             if(listenerEntry.referenceCount <= 0) {
 134                 listenerActorMap.remove(listener);
 135
 136                 if(listenerEntry.actorRef != null) {
 137                     LOG.debug("Killing EntityOwnershipListenerActor {}", listenerEntry.actorRef);
 138                     listenerEntry.actorRef.tell(PoisonPill.getInstance(), ActorRef.noSender());
 139                 }
 140             }
 141         }
 142     }
 143
 144     private ActorRef listenerActorFor(EntityOwnershipListener listener) {
 145         return listenerActorMap.get(listener).actorFor(listener);
 146     }
 147
 148     private class ListenerActorRefEntry {
 149         ActorRef actorRef;
 150         int referenceCount = 1;
 151
 152         ActorRef actorFor(EntityOwnershipListener listener) {
 153             if(actorRef == null) {
 154                 actorRef = actorContext.actorOf(EntityOwnershipListenerActor.props(listener));
 155
 156                 LOG.debug("{}: Created EntityOwnershipListenerActor {} for listener {}", logId, actorRef, listener);
 157             }
 158
 159             return actorRef;
 160         }
 161
 162         @Override
 163         public String toString() {
 164             return "ListenerActorRefEntry [actorRef=" + actorRef + ", referenceCount=" + referenceCount + "]";
 165         }
 166     }
 167 }