| /** |
| * 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.util; |
| |
| import java.io.*; |
| import java.util.Set; |
| import java.util.HashSet; |
| |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.commons.logging.Log; |
| |
| // Keeps track of which datanodes/tasktrackers are allowed to connect to the |
| // namenode/jobtracker. |
| public class HostsFileReader { |
| private Set<String> includes; |
| private Set<String> excludes; |
| private String includesFile; |
| private String excludesFile; |
| |
| private static final Log LOG = LogFactory.getLog(HostsFileReader.class); |
| |
| public HostsFileReader(String inFile, |
| String exFile) throws IOException { |
| includes = new HashSet<String>(); |
| excludes = new HashSet<String>(); |
| includesFile = inFile; |
| excludesFile = exFile; |
| refresh(); |
| } |
| |
| private void readFileToSet(String filename, Set<String> set) throws IOException { |
| File file = new File(filename); |
| if (!file.exists()) { |
| return; |
| } |
| FileInputStream fis = new FileInputStream(file); |
| BufferedReader reader = null; |
| try { |
| reader = new BufferedReader(new InputStreamReader(fis)); |
| String line; |
| while ((line = reader.readLine()) != null) { |
| String[] nodes = line.split("[ \t\n\f\r]+"); |
| if (nodes != null) { |
| for (int i = 0; i < nodes.length; i++) { |
| if (!nodes[i].equals("")) { |
| set.add(nodes[i]); // might need to add canonical name |
| } |
| } |
| } |
| } |
| } finally { |
| if (reader != null) { |
| reader.close(); |
| } |
| fis.close(); |
| } |
| } |
| |
| public synchronized void refresh() throws IOException { |
| LOG.info("Refreshing hosts (include/exclude) list"); |
| if (!includesFile.equals("")) { |
| Set<String> newIncludes = new HashSet<String>(); |
| readFileToSet(includesFile, newIncludes); |
| // switch the new hosts that are to be included |
| includes = newIncludes; |
| } |
| if (!excludesFile.equals("")) { |
| Set<String> newExcludes = new HashSet<String>(); |
| readFileToSet(excludesFile, newExcludes); |
| // switch the excluded hosts |
| excludes = newExcludes; |
| } |
| } |
| |
| public synchronized Set<String> getHosts() { |
| return includes; |
| } |
| |
| public synchronized Set<String> getExcludedHosts() { |
| return excludes; |
| } |
| |
| public synchronized void setIncludesFile(String includesFile) { |
| LOG.info("Setting the includes file to " + includesFile); |
| this.includesFile = includesFile; |
| } |
| |
| public synchronized void setExcludesFile(String excludesFile) { |
| LOG.info("Setting the excludes file to " + excludesFile); |
| this.excludesFile = excludesFile; |
| } |
| |
| public synchronized void updateFileNames(String includesFile, |
| String excludesFile) |
| throws IOException { |
| setIncludesFile(includesFile); |
| setExcludesFile(excludesFile); |
| } |
| } |