| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.yarn.server.resourcemanager.scheduler.placement; |
| |
| import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerNode; |
| |
| public class PlacementSetUtils { |
| /* |
| * If the {@link PlacementSet} only has one entry, return it. otherwise |
| * return null |
| */ |
| public static <N extends SchedulerNode> N getSingleNode(PlacementSet<N> ps) { |
| N node = null; |
| if (1 == ps.getAllNodes().size()) { |
| node = ps.getAllNodes().values().iterator().next(); |
| } |
| |
| return node; |
| } |
| } |