entityownership/mdsal-eos-dom-simple/src/main/java/org/opendaylight/mdsal/eos/dom/simple/SimpleDOMEntityOwnershipService.java

   1 /*
   2  * Copyright (c) 2017 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.mdsal.eos.dom.simple;
   9
  10 import static java.util.Objects.requireNonNull;
  11 import static org.opendaylight.mdsal.eos.common.api.EntityOwnershipChangeState.LOCAL_OWNERSHIP_GRANTED;
  12 import static org.opendaylight.mdsal.eos.common.api.EntityOwnershipChangeState.LOCAL_OWNERSHIP_LOST_NO_OWNER;
  13
  14 import com.google.common.annotations.VisibleForTesting;
  15 import com.google.common.base.MoreObjects;
  16 import com.google.common.base.MoreObjects.ToStringHelper;
  17 import com.google.common.collect.ArrayListMultimap;
  18 import com.google.common.collect.HashBasedTable;
  19 import com.google.common.collect.ImmutableList;
  20 import com.google.common.collect.Multimap;
  21 import com.google.common.collect.Table;
  22 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  23 import java.util.Collection;
  24 import java.util.Optional;
  25 import java.util.UUID;
  26 import org.checkerframework.checker.lock.qual.GuardedBy;
  27 import org.kohsuke.MetaInfServices;
  28 import org.opendaylight.mdsal.eos.common.api.CandidateAlreadyRegisteredException;
  29 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipChangeState;
  30 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipState;
  31 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  32 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipCandidateRegistration;
  33 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipChange;
  34 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipListener;
  35 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipListenerRegistration;
  36 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipService;
  37 import org.opendaylight.yangtools.concepts.AbstractObjectRegistration;
  38 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  39 import org.osgi.service.component.annotations.Component;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 @MetaInfServices
  44 @Component(immediate = true)
  45 public class SimpleDOMEntityOwnershipService implements DOMEntityOwnershipService {
  46     private static final Logger LOG = LoggerFactory.getLogger(SimpleDOMEntityOwnershipService.class);
  47
  48     @GuardedBy("entities")
  49     private final Table<String, YangInstanceIdentifier, DOMEntity> entities = HashBasedTable.create();
  50
  51     @GuardedBy("listeners")
  52     private final Multimap<String, DOMEntityOwnershipListener> listeners = ArrayListMultimap.create(0, 1);
  53
  54     private final UUID uuid;
  55
  56     @VisibleForTesting
  57     SimpleDOMEntityOwnershipService(final UUID uuid) {
  58         this.uuid = requireNonNull(uuid);
  59     }
  60
  61     public SimpleDOMEntityOwnershipService() {
  62         this(UUID.randomUUID());
  63     }
  64
  65     @Override
  66     public DOMEntityOwnershipCandidateRegistration registerCandidate(final DOMEntity entity)
  67             throws CandidateAlreadyRegisteredException {
  68         synchronized (entities) {
  69             final DOMEntity prev = entities.get(entity.getType(), entity.getIdentifier());
  70             if (prev != null) {
  71                 throw new CandidateAlreadyRegisteredException(prev);
  72             }
  73
  74             entities.put(entity.getType(), entity.getIdentifier(), entity);
  75             LOG.debug("{}: registered candidate {}", uuid, entity);
  76         }
  77
  78         notifyListeners(entity, LOCAL_OWNERSHIP_GRANTED);
  79         return new EntityRegistration(entity);
  80     }
  81
  82     @Override
  83     public DOMEntityOwnershipListenerRegistration registerListener(final String entityType,
  84             final DOMEntityOwnershipListener listener) {
  85
  86         final Collection<DOMEntity> owned;
  87         synchronized (entities) {
  88             owned = ImmutableList.copyOf(entities.row(entityType).values());
  89             LOG.trace("{}: acquired candidates {} for new listener {}", uuid, owned, listener);
  90         }
  91
  92         synchronized (listeners) {
  93             listeners.put(entityType, listener);
  94         }
  95
  96         for (DOMEntity entity : owned) {
  97             notifyListener(listener, new DOMEntityOwnershipChange(entity, LOCAL_OWNERSHIP_GRANTED));
  98         }
  99         LOG.debug("{}: registered listener {}", uuid, listener);
 100         return new ListenerRegistration(entityType, listener);
 101     }
 102
 103     @Override
 104     public Optional<EntityOwnershipState> getOwnershipState(final DOMEntity forEntity) {
 105         return isCandidateRegistered(forEntity) ? Optional.of(EntityOwnershipState.IS_OWNER) : Optional.empty();
 106     }
 107
 108     @Override
 109     public boolean isCandidateRegistered(final DOMEntity forEntity) {
 110         synchronized (entities) {
 111             return entities.contains(forEntity.getType(), forEntity.getIdentifier());
 112         }
 113     }
 114
 115     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
 116             justification = "https://github.com/spotbugs/spotbugs/issues/811")
 117     private void removeEntity(final DOMEntity entity) {
 118         synchronized (entities) {
 119             entities.remove(entity.getType(), entity.getIdentifier());
 120             LOG.debug("{}: unregistered candidate {}", uuid, entity);
 121         }
 122
 123         notifyListeners(entity, LOCAL_OWNERSHIP_LOST_NO_OWNER);
 124     }
 125
 126     @SuppressWarnings("checkstyle:illegalCatch")
 127     private void notifyListener(final DOMEntityOwnershipListener listener, final DOMEntityOwnershipChange change) {
 128         try {
 129             LOG.trace("{} notifying listener {} change {}", uuid, listener, change);
 130             listener.ownershipChanged(change);
 131         } catch (RuntimeException e) {
 132             LOG.warn("{}: Listener {} change {} failed", uuid, listener, change, e);
 133         }
 134     }
 135
 136     private void notifyListeners(final DOMEntity entity, final EntityOwnershipChangeState state) {
 137         final DOMEntityOwnershipChange change = new DOMEntityOwnershipChange(entity, state);
 138
 139         final Collection<DOMEntityOwnershipListener> snap;
 140
 141         synchronized (listeners) {
 142             snap = ImmutableList.copyOf(listeners.get(entity.getType()));
 143         }
 144
 145         for (DOMEntityOwnershipListener listener : snap) {
 146             notifyListener(listener, change);
 147         }
 148     }
 149
 150     void unregisterListener(final ListenerRegistration reg) {
 151         synchronized (listeners) {
 152             listeners.remove(reg.getEntityType(), reg.getInstance());
 153             LOG.debug("{}: unregistered listener {}", uuid, reg.getInstance());
 154         }
 155     }
 156
 157     @Override
 158     public String toString() {
 159         final ToStringHelper h = MoreObjects.toStringHelper(SimpleDOMEntityOwnershipService.class).add("uuid", uuid);
 160
 161         synchronized (entities) {
 162             h.add("entities", entities);
 163         }
 164         synchronized (listeners) {
 165             h.add("listeners", listeners);
 166         }
 167
 168         return h.toString();
 169     }
 170
 171     private final class EntityRegistration extends AbstractObjectRegistration<DOMEntity> implements
 172             DOMEntityOwnershipCandidateRegistration {
 173         EntityRegistration(final DOMEntity entity) {
 174             super(entity);
 175         }
 176
 177         @Override
 178         protected void removeRegistration() {
 179             removeEntity(getInstance());
 180         }
 181     }
 182
 183     private final class ListenerRegistration extends AbstractObjectRegistration<DOMEntityOwnershipListener>
 184             implements DOMEntityOwnershipListenerRegistration {
 185         private final String entityType;
 186
 187         ListenerRegistration(final String entityType, final DOMEntityOwnershipListener listener) {
 188             super(listener);
 189             this.entityType = requireNonNull(entityType);
 190         }
 191
 192         @Override
 193         public String getEntityType() {
 194             return entityType;
 195         }
 196
 197         @Override
 198         protected void removeRegistration() {
 199             unregisterListener(this);
 200         }
 201     }
 202 }