| /* |
| * 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.slider.server.appmaster.state; |
| |
| import org.apache.hadoop.yarn.api.records.Container; |
| import org.apache.hadoop.yarn.api.records.NodeId; |
| import org.apache.slider.common.tools.SliderUtils; |
| |
| public class RoleHistoryUtils { |
| |
| public static String hostnameOf(Container container) { |
| NodeId nodeId = container.getNodeId(); |
| if (nodeId== null) { |
| throw new RuntimeException("Container has no node ID: %s" + |
| SliderUtils.containerToString(container)); |
| } |
| return nodeId.getHost(); |
| } |
| |
| /** |
| * Decrement a value but hold it at zero. Usually a sanity check |
| * on counters tracking outstanding operations |
| * @param val value |
| * @return decremented value |
| */ |
| public static int decToFloor(int val) { |
| int v = val-1; |
| if (v < 0) { |
| v = 0; |
| } |
| return v; |
| } |
| |
| } |