opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/selectionstrategy/FirstCandidateSelectionStrategy.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.selectionstrategy;
  10
  11 import com.google.common.base.Preconditions;
  12 import java.util.Collection;
  13 import java.util.Collections;
  14 import java.util.Map;
  15
  16 /**
  17  * The FirstCandidateSelectionStrategy always selects the first viable candidate from the list of candidates
  18  */
  19 public class FirstCandidateSelectionStrategy extends AbstractEntityOwnerSelectionStrategy {
  20
  21     public static final FirstCandidateSelectionStrategy INSTANCE = new FirstCandidateSelectionStrategy(0L, Collections.emptyMap());
  22
  23     public FirstCandidateSelectionStrategy(long selectionDelayInMillis, Map<String, Long> initialStatistics) {
  24         super(selectionDelayInMillis, initialStatistics);
  25     }
  26
  27     @Override
  28     public String newOwner(String currentOwner, Collection<String> viableCandidates) {
  29         Preconditions.checkArgument(viableCandidates.size() > 0, "No viable candidates provided");
  30         return viableCandidates.iterator().next();
  31     }
  32 }