| /** |
| * 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.mapred; |
| |
| import java.io.IOException; |
| import java.security.PrivilegedExceptionAction; |
| import java.util.concurrent.LinkedBlockingQueue; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.security.UserGroupInformation; |
| |
| class CleanupQueue { |
| |
| public static final Log LOG = |
| LogFactory.getLog(CleanupQueue.class); |
| |
| private static final PathCleanupThread cleanupThread = |
| new PathCleanupThread(); |
| private static final CleanupQueue inst = new CleanupQueue(); |
| |
| public static CleanupQueue getInstance() { return inst; } |
| |
| /** |
| * Create a singleton path-clean-up queue. It can be used to delete |
| * paths(directories/files) in a separate thread. This constructor creates a |
| * clean-up thread and also starts it as a daemon. Callers can instantiate one |
| * CleanupQueue per JVM and can use it for deleting paths. Use |
| * {@link CleanupQueue#addToQueue(PathDeletionContext...)} to add paths for |
| * deletion. |
| */ |
| protected CleanupQueue() { } |
| |
| /** |
| * Contains info related to the path of the file/dir to be deleted |
| */ |
| static class PathDeletionContext { |
| final Path fullPath;// full path of file or dir |
| final Configuration conf; |
| |
| public PathDeletionContext(Path fullPath, Configuration conf) { |
| this.fullPath = fullPath; |
| this.conf = conf; |
| } |
| |
| protected Path getPathForCleanup() { |
| return fullPath; |
| } |
| |
| /** |
| * Deletes the path (and its subdirectories recursively) |
| * @throws IOException, InterruptedException |
| */ |
| protected void deletePath() throws IOException, InterruptedException { |
| final Path p = getPathForCleanup(); |
| UserGroupInformation.getLoginUser().doAs( |
| new PrivilegedExceptionAction<Object>() { |
| public Object run() throws IOException { |
| p.getFileSystem(conf).delete(p, true); |
| return null; |
| } |
| }); |
| } |
| |
| @Override |
| public String toString() { |
| final Path p = getPathForCleanup(); |
| return (null == p) ? "undefined" : p.toString(); |
| } |
| } |
| |
| /** |
| * Adds the paths to the queue of paths to be deleted by cleanupThread. |
| */ |
| public void addToQueue(PathDeletionContext... contexts) { |
| cleanupThread.addToQueue(contexts); |
| } |
| |
| // currently used by tests only |
| protected boolean isQueueEmpty() { |
| return (cleanupThread.queue.size() == 0); |
| } |
| |
| private static class PathCleanupThread extends Thread { |
| |
| // cleanup queue which deletes files/directories of the paths queued up. |
| private LinkedBlockingQueue<PathDeletionContext> queue = |
| new LinkedBlockingQueue<PathDeletionContext>(); |
| |
| public PathCleanupThread() { |
| setName("Directory/File cleanup thread"); |
| setDaemon(true); |
| start(); |
| } |
| |
| void addToQueue(PathDeletionContext[] contexts) { |
| for (PathDeletionContext context : contexts) { |
| try { |
| queue.put(context); |
| } catch(InterruptedException ie) {} |
| } |
| } |
| |
| public void run() { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug(getName() + " started."); |
| } |
| PathDeletionContext context = null; |
| while (true) { |
| try { |
| context = queue.take(); |
| context.deletePath(); |
| // delete the path. |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("DELETED " + context); |
| } |
| } catch (InterruptedException t) { |
| LOG.warn("Interrupted deletion of " + context); |
| return; |
| } catch (Throwable e) { |
| LOG.warn("Error deleting path " + context, e); |
| } |
| } |
| } |
| } |
| } |