StaticMapping.java
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上传日期:2018-01-08
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- /**
- * 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.net;
- import java.util.*;
- import org.apache.hadoop.conf.Configuration;
- import org.apache.hadoop.conf.Configured;
- /**
- * Implements the {@link DNSToSwitchMapping} via static mappings. Used
- * in testcases that simulate racks.
- *
- */
- public class StaticMapping extends Configured implements DNSToSwitchMapping {
- public void setconf(Configuration conf) {
- String[] mappings = conf.getStrings("hadoop.configured.node.mapping");
- if (mappings != null) {
- for (int i = 0; i < mappings.length; i++) {
- String str = mappings[i];
- String host = str.substring(0, str.indexOf('='));
- String rack = str.substring(str.indexOf('=') + 1);
- addNodeToRack(host, rack);
- }
- }
- }
- /* Only one instance per JVM */
- private static Map<String, String> nameToRackMap = new HashMap<String, String>();
-
- static synchronized public void addNodeToRack(String name, String rackId) {
- nameToRackMap.put(name, rackId);
- }
- public List<String> resolve(List<String> names) {
- List<String> m = new ArrayList<String>();
- synchronized (nameToRackMap) {
- for (String name : names) {
- String rackId;
- if ((rackId = nameToRackMap.get(name)) != null) {
- m.add(rackId);
- } else {
- m.add(NetworkTopology.DEFAULT_RACK);
- }
- }
- return m;
- }
- }
- }