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
  14 /**
  15  * The FirstCandidateSelectionStrategy always selects the first viable candidate from the list of candidates
  16  */
  17 public class FirstCandidateSelectionStrategy implements EntityOwnerSelectionStrategy {
  18
  19     public static final FirstCandidateSelectionStrategy INSTANCE = new FirstCandidateSelectionStrategy();
  20
  21     @Override
  22     public long selectionDelayInMillis() {
  23         return 0;
  24     }
  25
  26     @Override
  27     public String newOwner(Collection<String> viableCandidates) {
  28         Preconditions.checkArgument(viableCandidates.size() > 0, "No viable candidates provided");
  29         return viableCandidates.iterator().next();
  30     }
  31 }