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
  16 import akka.actor.ActorRef;
  17 import com.google.common.base.Optional;
  18 import com.google.common.base.Preconditions;
  19 import java.util.ArrayList;
  20 import java.util.Collection;
  21 import java.util.Collections;
  22 import java.util.HashMap;
  23 import java.util.LinkedHashSet;
  24 import java.util.List;
  25 import java.util.Map;
  26 import java.util.Map.Entry;
  27 import org.opendaylight.controller.cluster.datastore.ShardDataTree;
  28 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateAdded;
  29 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateRemoved;
  30 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.entity.owners.rev150804.entity.owners.EntityType;
  32 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;
  33 import org.opendaylight.yangtools.yang.common.QName;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  36 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  37 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  38 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  39 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 /**
  44  * Listens for candidate entries added/removed and notifies the EntityOwnershipShard appropriately.
  45  *
  46  * @author Moiz Raja
  47  * @author Thomas Pantelis
  48  */
  49 class CandidateListChangeListener implements DOMDataTreeChangeListener {
  50     private static final Logger LOG = LoggerFactory.getLogger(CandidateListChangeListener.class);
  51
  52     private final String logId;
  53     private final ActorRef shard;
  54     private final Map<YangInstanceIdentifier, Collection<String>> currentCandidates = new HashMap<>();
  55
  56     CandidateListChangeListener(ActorRef shard, String logId) {
  57         this.shard = Preconditions.checkNotNull(shard, "shard should not be null");
  58         this.logId = logId;
  59     }
  60
  61     void init(ShardDataTree shardDataTree) {
  62         shardDataTree.registerTreeChangeListener(YangInstanceIdentifier.builder(ENTITY_OWNERS_PATH)
  63             .node(EntityType.QNAME).node(EntityType.QNAME).node(ENTITY_QNAME).node(ENTITY_QNAME)
  64                 .node(Candidate.QNAME).node(Candidate.QNAME).build(), this, Optional.absent(), noop -> { /* NOOP */ });
  65     }
  66
  67     @Override
  68     public void onDataTreeChanged(Collection<DataTreeCandidate> changes) {
  69         for (DataTreeCandidate change: changes) {
  70             DataTreeCandidateNode changeRoot = change.getRootNode();
  71             ModificationType type = changeRoot.getModificationType();
  72
  73             LOG.debug("{}: Candidate node changed: {}, {}", logId, type, change.getRootPath());
  74
  75             NodeIdentifierWithPredicates candidateKey =
  76                     (NodeIdentifierWithPredicates) change.getRootPath().getLastPathArgument();
  77             String candidate = candidateKey.getKeyValues().get(CANDIDATE_NAME_QNAME).toString();
  78
  79             YangInstanceIdentifier entityId = extractEntityPath(change.getRootPath());
  80
  81             if (type == ModificationType.WRITE || type == ModificationType.APPEARED) {
  82                 LOG.debug("{}: Candidate {} was added for entity {}", logId, candidate, entityId);
  83
  84                 Collection<String> newCandidates = addToCurrentCandidates(entityId, candidate);
  85                 shard.tell(new CandidateAdded(entityId, candidate, new ArrayList<>(newCandidates)), shard);
  86             } else if (type == ModificationType.DELETE || type == ModificationType.DISAPPEARED) {
  87                 LOG.debug("{}: Candidate {} was removed for entity {}", logId, candidate, entityId);
  88
  89                 Collection<String> newCandidates = removeFromCurrentCandidates(entityId, candidate);
  90                 shard.tell(new CandidateRemoved(entityId, candidate, new ArrayList<>(newCandidates)), shard);
  91             }
  92         }
  93     }
  94
  95     private Collection<String> addToCurrentCandidates(YangInstanceIdentifier entityId, String newCandidate) {
  96         Collection<String> candidates = currentCandidates.get(entityId);
  97         if (candidates == null) {
  98             candidates = new LinkedHashSet<>();
  99             currentCandidates.put(entityId, candidates);
 100         }
 101
 102         candidates.add(newCandidate);
 103         return candidates;
 104     }
 105
 106     private Collection<String> removeFromCurrentCandidates(YangInstanceIdentifier entityId, String candidateToRemove) {
 107         Collection<String> candidates = currentCandidates.get(entityId);
 108         if (candidates != null) {
 109             candidates.remove(candidateToRemove);
 110             return candidates;
 111         }
 112
 113         // Shouldn't happen
 114         return Collections.emptyList();
 115     }
 116
 117     private static YangInstanceIdentifier extractEntityPath(YangInstanceIdentifier candidatePath) {
 118         List<PathArgument> newPathArgs = new ArrayList<>();
 119         for (PathArgument pathArg: candidatePath.getPathArguments()) {
 120             newPathArgs.add(pathArg);
 121             if (pathArg instanceof NodeIdentifierWithPredicates) {
 122                 NodeIdentifierWithPredicates nodeKey = (NodeIdentifierWithPredicates) pathArg;
 123                 Entry<QName, Object> key = nodeKey.getKeyValues().entrySet().iterator().next();
 124                 if (ENTITY_ID_QNAME.equals(key.getKey())) {
 125                     break;
 126                 }
 127             }
 128         }
 129
 130         return YangInstanceIdentifier.create(newPathArgs);
 131     }
 132 }