opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/CandidateListChangeListener.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.controller.cluster.datastore.entityownership;
  10
  11 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NAME_QNAME;
  12 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_ID_QNAME;
  13 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_OWNERS_PATH;
  14 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_QNAME;
  15 import akka.actor.ActorRef;
  16 import com.google.common.base.Preconditions;
  17 import java.util.ArrayList;
  18 import java.util.Collection;
  19 import java.util.Collections;
  20 import java.util.HashMap;
  21 import java.util.LinkedHashSet;
  22 import java.util.List;
  23 import java.util.Map;
  24 import java.util.Map.Entry;
  25 import org.opendaylight.controller.cluster.datastore.ShardDataTree;
  26 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateAdded;
  27 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateRemoved;
  28 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.entity.owners.rev150804.entity.owners.EntityType;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.entity.owners.rev150804.entity.owners.entity.type.entity.Candidate;
  31 import org.opendaylight.yangtools.yang.common.QName;
  32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  35 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  36 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  37 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 /**
  42  * Listens for candidate entries added/removed and notifies the EntityOwnershipShard appropriately.
  43  *
  44  * @author Moiz Raja
  45  * @author Thomas Pantelis
  46  */
  47 class CandidateListChangeListener implements DOMDataTreeChangeListener {
  48     private static final Logger LOG = LoggerFactory.getLogger(CandidateListChangeListener.class);
  49
  50     private final String logId;
  51     private final ActorRef shard;
  52     private final Map<YangInstanceIdentifier, Collection<String>> currentCandidates = new HashMap<>();
  53
  54     CandidateListChangeListener(ActorRef shard, String logId) {
  55         this.shard = Preconditions.checkNotNull(shard, "shard should not be null");
  56         this.logId = logId;
  57     }
  58
  59     void init(ShardDataTree shardDataTree) {
  60         shardDataTree.registerTreeChangeListener(YangInstanceIdentifier.builder(ENTITY_OWNERS_PATH).
  61                 node(EntityType.QNAME).node(EntityType.QNAME).node(ENTITY_QNAME).node(ENTITY_QNAME).
  62                         node(Candidate.QNAME).node(Candidate.QNAME).build(), this);
  63     }
  64
  65     @Override
  66     public void onDataTreeChanged(Collection<DataTreeCandidate> changes) {
  67         for(DataTreeCandidate change: changes) {
  68             DataTreeCandidateNode changeRoot = change.getRootNode();
  69             ModificationType type = changeRoot.getModificationType();
  70
  71             LOG.debug("{}: Candidate node changed: {}, {}", logId, type, change.getRootPath());
  72
  73             NodeIdentifierWithPredicates candidateKey =
  74                     (NodeIdentifierWithPredicates) change.getRootPath().getLastPathArgument();
  75             String candidate = candidateKey.getKeyValues().get(CANDIDATE_NAME_QNAME).toString();
  76
  77             YangInstanceIdentifier entityId = extractEntityPath(change.getRootPath());
  78
  79             if(type == ModificationType.WRITE || type == ModificationType.APPEARED) {
  80                 LOG.debug("{}: Candidate {} was added for entity {}", logId, candidate, entityId);
  81
  82                 Collection<String> currentCandidates = addToCurrentCandidates(entityId, candidate);
  83                 shard.tell(new CandidateAdded(entityId, candidate, new ArrayList<>(currentCandidates)), shard);
  84             } else if(type == ModificationType.DELETE || type == ModificationType.DISAPPEARED) {
  85                 LOG.debug("{}: Candidate {} was removed for entity {}", logId, candidate, entityId);
  86
  87                 Collection<String> currentCandidates = removeFromCurrentCandidates(entityId, candidate);
  88                 shard.tell(new CandidateRemoved(entityId, candidate, new ArrayList<>(currentCandidates)), shard);
  89             }
  90         }
  91     }
  92
  93     private Collection<String> addToCurrentCandidates(YangInstanceIdentifier entityId, String newCandidate) {
  94         Collection<String> candidates = currentCandidates.get(entityId);
  95         if(candidates == null) {
  96             candidates = new LinkedHashSet<>();
  97             currentCandidates.put(entityId, candidates);
  98         }
  99
 100         candidates.add(newCandidate);
 101         return candidates;
 102     }
 103
 104     private Collection<String> removeFromCurrentCandidates(YangInstanceIdentifier entityId, String candidateToRemove) {
 105         Collection<String> candidates = currentCandidates.get(entityId);
 106         if(candidates != null) {
 107             candidates.remove(candidateToRemove);
 108             return candidates;
 109         }
 110
 111         // Shouldn't happen
 112         return Collections.emptyList();
 113     }
 114
 115     private static YangInstanceIdentifier extractEntityPath(YangInstanceIdentifier candidatePath) {
 116         List<PathArgument> newPathArgs = new ArrayList<>();
 117         for(PathArgument pathArg: candidatePath.getPathArguments()) {
 118             newPathArgs.add(pathArg);
 119             if(pathArg instanceof NodeIdentifierWithPredicates) {
 120                 NodeIdentifierWithPredicates nodeKey = (NodeIdentifierWithPredicates) pathArg;
 121                 Entry<QName, Object> key = nodeKey.getKeyValues().entrySet().iterator().next();
 122                 if(ENTITY_ID_QNAME.equals(key.getKey())) {
 123                     break;
 124                 }
 125             }
 126         }
 127
 128         return YangInstanceIdentifier.create(newPathArgs);
 129     }
 130 }