opendaylight/netconf/abstract-topology/src/main/java/org/opendaylight/netconf/topology/util/NodeRoleChangeStrategy.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
   9 package org.opendaylight.netconf.topology.util;
  10
  11 import org.opendaylight.controller.md.sal.common.api.clustering.CandidateAlreadyRegisteredException;
  12 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  13 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipCandidateRegistration;
  14 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipChange;
  15 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  16 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListenerRegistration;
  17 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipService;
  18 import org.opendaylight.netconf.topology.RoleChangeStrategy;
  19 import org.opendaylight.netconf.topology.NodeListener;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 public class NodeRoleChangeStrategy implements RoleChangeStrategy, EntityOwnershipListener {
  24
  25     private static final Logger LOG = LoggerFactory.getLogger(NodeRoleChangeStrategy.class);
  26
  27     private final EntityOwnershipService entityOwnershipService;
  28     private final String entityType;
  29     private final String entityName;
  30     private final Entity entity;
  31     private NodeListener ownershipCandidate;
  32
  33     private EntityOwnershipCandidateRegistration candidateRegistration = null;
  34     private EntityOwnershipListenerRegistration ownershipListenerRegistration = null;
  35
  36     public NodeRoleChangeStrategy(final EntityOwnershipService entityOwnershipService,
  37                                   final String entityType,
  38                                   final String entityName) {
  39         this.entityOwnershipService = entityOwnershipService;
  40         this.entityType = entityType + "/" + entityName;
  41         this.entityName = entityName;
  42         this.entity = new Entity(this.entityType, entityName);
  43     }
  44
  45     @Override
  46     public void registerRoleCandidate(NodeListener electionCandidate) {
  47         LOG.debug("Registering role candidate type: {} , name: {}", entityType, entityName);
  48         this.ownershipCandidate = electionCandidate;
  49         try {
  50             if (candidateRegistration != null) {
  51                 unregisterRoleCandidate();
  52             }
  53             candidateRegistration = entityOwnershipService.registerCandidate(entity);
  54             ownershipListenerRegistration = entityOwnershipService.registerListener(entityType, this);
  55         } catch (CandidateAlreadyRegisteredException e) {
  56             LOG.error("Candidate already registered for election", e);
  57             throw new IllegalStateException("Candidate already registered for election", e);
  58         }
  59     }
  60
  61     @Override
  62     public void unregisterRoleCandidate() {
  63         LOG.debug("Unregistering role candidate");
  64         candidateRegistration.close();
  65         candidateRegistration = null;
  66         ownershipListenerRegistration.close();
  67         ownershipListenerRegistration = null;
  68     }
  69
  70     @Override
  71     public boolean isCandidateRegistered() {
  72         return entityOwnershipService.isCandidateRegistered(entity);
  73     }
  74
  75     @Override
  76     public void onRoleChanged(RoleChangeDTO roleChangeDTO) {
  77         LOG.debug("Role was changed {}", roleChangeDTO);
  78         ownershipCandidate.onRoleChanged(roleChangeDTO);
  79     }
  80
  81     @Override
  82     public void ownershipChanged(EntityOwnershipChange ownershipChange) {
  83         LOG.debug("Ownership has changed {}", ownershipChange);
  84         ownershipCandidate.onRoleChanged(new RoleChangeDTO(ownershipChange.wasOwner(), ownershipChange.isOwner(), ownershipChange.hasOwner()));
  85     }
  86 }