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 package org.opendaylight.controller.cluster.datastore.entityownership;
   9
  10 import static java.util.Objects.requireNonNull;
  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 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 java.util.Optional;
  26 import org.opendaylight.controller.cluster.datastore.ShardDataTree;
  27 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateAdded;
  28 import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateRemoved;
  29 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.entity.owners.rev150804.entity.owners.EntityType;
  31 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;
  32 import org.opendaylight.yangtools.yang.common.QName;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  36 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  37 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  38 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * Listens for candidate entries added/removed and notifies the EntityOwnershipShard appropriately.
  44  *
  45  * @author Moiz Raja
  46  * @author Thomas Pantelis
  47  */
  48 class CandidateListChangeListener implements DOMDataTreeChangeListener {
  49     private static final Logger LOG = LoggerFactory.getLogger(CandidateListChangeListener.class);
  50
  51     private final String logId;
  52     private final ActorRef shard;
  53     private final Map<YangInstanceIdentifier, Collection<String>> currentCandidates = new HashMap<>();
  54
  55     CandidateListChangeListener(final ActorRef shard, final String logId) {
  56         this.shard = requireNonNull(shard, "shard should not be null");
  57         this.logId = logId;
  58     }
  59
  60     void init(final ShardDataTree shardDataTree) {
  61         shardDataTree.registerTreeChangeListener(YangInstanceIdentifier.builder(ENTITY_OWNERS_PATH)
  62             .node(EntityType.QNAME).node(EntityType.QNAME).node(ENTITY_QNAME).node(ENTITY_QNAME)
  63                 .node(Candidate.QNAME).node(Candidate.QNAME).build(), this, Optional.empty(), noop -> { /* NOOP */ });
  64     }
  65
  66     @Override
  67     public void onDataTreeChanged(final Collection<DataTreeCandidate> changes) {
  68         for (DataTreeCandidate change: changes) {
  69             DataTreeCandidateNode changeRoot = change.getRootNode();
  70             ModificationType type = changeRoot.getModificationType();
  71
  72             LOG.debug("{}: Candidate node changed: {}, {}", logId, type, change.getRootPath());
  73
  74             NodeIdentifierWithPredicates candidateKey =
  75                     (NodeIdentifierWithPredicates) change.getRootPath().getLastPathArgument();
  76             String candidate = candidateKey.getKeyValues().get(CANDIDATE_NAME_QNAME).toString();
  77
  78             YangInstanceIdentifier entityId = extractEntityPath(change.getRootPath());
  79
  80             if (type == ModificationType.WRITE || type == ModificationType.APPEARED) {
  81                 LOG.debug("{}: Candidate {} was added for entity {}", logId, candidate, entityId);
  82
  83                 Collection<String> newCandidates = addToCurrentCandidates(entityId, candidate);
  84                 shard.tell(new CandidateAdded(entityId, candidate, new ArrayList<>(newCandidates)), shard);
  85             } else if (type == ModificationType.DELETE || type == ModificationType.DISAPPEARED) {
  86                 LOG.debug("{}: Candidate {} was removed for entity {}", logId, candidate, entityId);
  87
  88                 Collection<String> newCandidates = removeFromCurrentCandidates(entityId, candidate);
  89                 shard.tell(new CandidateRemoved(entityId, candidate, new ArrayList<>(newCandidates)), shard);
  90             }
  91         }
  92     }
  93
  94     private Collection<String> addToCurrentCandidates(final YangInstanceIdentifier entityId,
  95             final String newCandidate) {
  96         Collection<String> candidates = currentCandidates.computeIfAbsent(entityId, k -> new LinkedHashSet<>());
  97         candidates.add(newCandidate);
  98         return candidates;
  99     }
 100
 101     private Collection<String> removeFromCurrentCandidates(final YangInstanceIdentifier entityId,
 102             final String candidateToRemove) {
 103         Collection<String> candidates = currentCandidates.get(entityId);
 104         if (candidates != null) {
 105             candidates.remove(candidateToRemove);
 106             return candidates;
 107         }
 108
 109         // Shouldn't happen
 110         return Collections.emptyList();
 111     }
 112
 113     private static YangInstanceIdentifier extractEntityPath(final YangInstanceIdentifier candidatePath) {
 114         List<PathArgument> newPathArgs = new ArrayList<>();
 115         for (PathArgument pathArg: candidatePath.getPathArguments()) {
 116             newPathArgs.add(pathArg);
 117             if (pathArg instanceof NodeIdentifierWithPredicates) {
 118                 NodeIdentifierWithPredicates nodeKey = (NodeIdentifierWithPredicates) pathArg;
 119                 Entry<QName, Object> key = nodeKey.getKeyValues().entrySet().iterator().next();
 120                 if (ENTITY_ID_QNAME.equals(key.getKey())) {
 121                     break;
 122                 }
 123             }
 124         }
 125
 126         return YangInstanceIdentifier.create(newPathArgs);
 127     }
 128 }