opendaylight/md-sal/sal-distributed-eos/src/main/java/org/opendaylight/controller/cluster/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 package org.opendaylight.controller.cluster.entityownership.selectionstrategy;
   9
  10 import com.google.common.base.Preconditions;
  11 import java.util.Collection;
  12 import java.util.Collections;
  13 import java.util.Map;
  14
  15 /**
  16  * The FirstCandidateSelectionStrategy always selects the first viable candidate from the list of candidates.
  17  */
  18 public class FirstCandidateSelectionStrategy extends AbstractEntityOwnerSelectionStrategy {
  19
  20     public static final FirstCandidateSelectionStrategy INSTANCE =
  21             new FirstCandidateSelectionStrategy(0L, Collections.emptyMap());
  22
  23     public FirstCandidateSelectionStrategy(final long selectionDelayInMillis,
  24             final Map<String, Long> initialStatistics) {
  25         super(selectionDelayInMillis, initialStatistics);
  26     }
  27
  28     @Override
  29     public String newOwner(final String currentOwner, final Collection<String> viableCandidates) {
  30         Preconditions.checkArgument(viableCandidates.size() > 0, "No viable candidates provided");
  31         return viableCandidates.iterator().next();
  32     }
  33 }