Implement LeastLoadedCandidateSelectionStrategy
[controller.git] / 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.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 = new FirstCandidateSelectionStrategy(0L);
21
22     public FirstCandidateSelectionStrategy(long selectionDelayInMillis) {
23         super(selectionDelayInMillis);
24     }
25
26     @Override
27     public String newOwner(Collection<String> viableCandidates, Map<String, Long> statistics) {
28         Preconditions.checkArgument(viableCandidates.size() > 0, "No viable candidates provided");
29         return viableCandidates.iterator().next();
30     }
31 }