| /** |
| * 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.File; |
| import java.io.IOException; |
| |
| /** |
| * Class that provides utility functions for checking disk problem |
| */ |
| |
| public class DiskChecker { |
| |
| public static class DiskErrorException extends IOException { |
| public DiskErrorException(String msg) { |
| super(msg); |
| } |
| } |
| |
| public static class DiskOutOfSpaceException extends IOException { |
| public DiskOutOfSpaceException(String msg) { |
| super(msg); |
| } |
| } |
| |
| /** |
| * The semantics of mkdirsWithExistsCheck method is different from the mkdirs |
| * method provided in the Sun's java.io.File class in the following way: |
| * While creating the non-existent parent directories, this method checks for |
| * the existence of those directories if the mkdir fails at any point (since |
| * that directory might have just been created by some other process). |
| * If both mkdir() and the exists() check fails for any seemingly |
| * non-existent directory, then we signal an error; Sun's mkdir would signal |
| * an error (return false) if a directory it is attempting to create already |
| * exists or the mkdir fails. |
| * @param dir |
| * @return true on success, false on failure |
| */ |
| public static boolean mkdirsWithExistsCheck(File dir) { |
| if (dir.mkdir() || dir.exists()) { |
| return true; |
| } |
| File canonDir = null; |
| try { |
| canonDir = dir.getCanonicalFile(); |
| } catch (IOException e) { |
| return false; |
| } |
| String parent = canonDir.getParent(); |
| return (parent != null) && |
| (mkdirsWithExistsCheck(new File(parent)) && |
| (canonDir.mkdir() || canonDir.exists())); |
| } |
| |
| public static void checkDir(File dir) throws DiskErrorException { |
| if (!mkdirsWithExistsCheck(dir)) |
| throw new DiskErrorException("can not create directory: " |
| + dir.toString()); |
| |
| if (!dir.isDirectory()) |
| throw new DiskErrorException("not a directory: " |
| + dir.toString()); |
| |
| if (!dir.canRead()) |
| throw new DiskErrorException("directory is not readable: " |
| + dir.toString()); |
| |
| if (!dir.canWrite()) |
| throw new DiskErrorException("directory is not writable: " |
| + dir.toString()); |
| } |
| |
| } |