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