| /** |
| * 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.fs; |
| |
| import java.text.*; |
| import java.io.*; |
| import java.util.Date; |
| |
| import org.apache.commons.logging.*; |
| |
| import org.apache.hadoop.conf.*; |
| import org.apache.hadoop.fs.permission.*; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** Provides a <i>trash</i> feature. Files are moved to a user's trash |
| * directory, a subdirectory of their home directory named ".Trash". Files are |
| * initially moved to a <i>current</i> sub-directory of the trash directory. |
| * Within that sub-directory their original path is preserved. Periodically |
| * one may checkpoint the current trash and remove older checkpoints. (This |
| * design permits trash management without enumeration of the full trash |
| * content, without date support in the filesystem, and without clock |
| * synchronization.) |
| */ |
| public class Trash extends Configured { |
| private static final Log LOG = |
| LogFactory.getLog(Trash.class); |
| |
| private static final Path CURRENT = new Path("Current"); |
| private static final Path TRASH = new Path(".Trash/"); |
| private static final Path HOMES = new Path("/user/"); |
| |
| private static final FsPermission PERMISSION = |
| new FsPermission(FsAction.ALL, FsAction.NONE, FsAction.NONE); |
| |
| private static final DateFormat CHECKPOINT = new SimpleDateFormat("yyMMddHHmm"); |
| private static final int MSECS_PER_MINUTE = 60*1000; |
| |
| private final FileSystem fs; |
| private final Path trash; |
| private final Path current; |
| private final long interval; |
| |
| /** Construct a trash can accessor. |
| * @param conf a Configuration |
| */ |
| public Trash(Configuration conf) throws IOException { |
| this(FileSystem.get(conf), conf); |
| } |
| |
| /** |
| * Construct a trash can accessor for the FileSystem provided. |
| */ |
| public Trash(FileSystem fs, Configuration conf) throws IOException { |
| super(conf); |
| this.fs = fs; |
| this.trash = new Path(fs.getHomeDirectory(), TRASH); |
| this.current = new Path(trash, CURRENT); |
| this.interval = conf.getLong("fs.trash.interval", 60) * MSECS_PER_MINUTE; |
| } |
| |
| private Trash(Path home, Configuration conf) throws IOException { |
| super(conf); |
| this.fs = home.getFileSystem(conf); |
| this.trash = new Path(home, TRASH); |
| this.current = new Path(trash, CURRENT); |
| this.interval = conf.getLong("fs.trash.interval", 60) * MSECS_PER_MINUTE; |
| } |
| |
| private Path makeTrashRelativePath(Path basePath, Path rmFilePath) { |
| return new Path(basePath + rmFilePath.toUri().getPath()); |
| } |
| |
| /** Move a file or directory to the current trash directory. |
| * @return false if the item is already in the trash or trash is disabled |
| */ |
| public boolean moveToTrash(Path path) throws IOException { |
| if (interval == 0) |
| return false; |
| |
| if (!path.isAbsolute()) // make path absolute |
| path = new Path(fs.getWorkingDirectory(), path); |
| |
| if (!fs.exists(path)) // check that path exists |
| throw new FileNotFoundException(path.toString()); |
| |
| String qpath = path.makeQualified(fs).toString(); |
| |
| if (qpath.startsWith(trash.toString())) { |
| return false; // already in trash |
| } |
| |
| if (trash.getParent().toString().startsWith(qpath)) { |
| throw new IOException("Cannot move \"" + path + |
| "\" to the trash, as it contains the trash"); |
| } |
| |
| Path trashPath = makeTrashRelativePath(current, path); |
| Path baseTrashPath = makeTrashRelativePath(current, path.getParent()); |
| |
| IOException cause = null; |
| |
| // try twice, in case checkpoint between the mkdirs() & rename() |
| for (int i = 0; i < 2; i++) { |
| try { |
| if (!fs.mkdirs(baseTrashPath, PERMISSION)) { // create current |
| LOG.warn("Can't create(mkdir) trash directory: "+baseTrashPath); |
| return false; |
| } |
| } catch (IOException e) { |
| LOG.warn("Can't create trash directory: "+baseTrashPath); |
| cause = e; |
| break; |
| } |
| try { |
| // |
| // if the target path in Trash already exists, then append with |
| // a number. Start from 1. |
| // |
| String orig = trashPath.toString(); |
| for (int j = 1; fs.exists(trashPath); j++) { |
| trashPath = new Path(orig + "." + j); |
| } |
| if (fs.rename(path, trashPath)) // move to current trash |
| return true; |
| } catch (IOException e) { |
| cause = e; |
| } |
| } |
| throw (IOException) |
| new IOException("Failed to move to trash: "+path).initCause(cause); |
| } |
| |
| /** Create a trash checkpoint. */ |
| public void checkpoint() throws IOException { |
| if (!fs.exists(current)) // no trash, no checkpoint |
| return; |
| |
| Path checkpoint; |
| synchronized (CHECKPOINT) { |
| checkpoint = new Path(trash, CHECKPOINT.format(new Date())); |
| } |
| |
| if (fs.rename(current, checkpoint)) { |
| LOG.info("Created trash checkpoint: "+checkpoint.toUri().getPath()); |
| } else { |
| throw new IOException("Failed to checkpoint trash: "+checkpoint); |
| } |
| } |
| |
| /** Delete old checkpoints. */ |
| public void expunge() throws IOException { |
| FileStatus[] dirs = fs.listStatus(trash); // scan trash sub-directories |
| if( dirs == null){ |
| return; |
| } |
| long now = System.currentTimeMillis(); |
| for (int i = 0; i < dirs.length; i++) { |
| Path path = dirs[i].getPath(); |
| String dir = path.toUri().getPath(); |
| String name = path.getName(); |
| if (name.equals(CURRENT.getName())) // skip current |
| continue; |
| |
| long time; |
| try { |
| synchronized (CHECKPOINT) { |
| time = CHECKPOINT.parse(name).getTime(); |
| } |
| } catch (ParseException e) { |
| LOG.warn("Unexpected item in trash: "+dir+". Ignoring."); |
| continue; |
| } |
| |
| if ((now - interval) > time) { |
| if (fs.delete(path, true)) { |
| LOG.info("Deleted trash checkpoint: "+dir); |
| } else { |
| LOG.warn("Couldn't delete checkpoint: "+dir+" Ignoring."); |
| } |
| } |
| } |
| } |
| |
| // |
| // get the current working directory |
| // |
| Path getCurrentTrashDir() { |
| return current; |
| } |
| |
| /** Return a {@link Runnable} that periodically empties the trash of all |
| * users, intended to be run by the superuser. Only one checkpoint is kept |
| * at a time. |
| */ |
| public Runnable getEmptier() throws IOException { |
| return new Emptier(getConf()); |
| } |
| |
| private static class Emptier implements Runnable { |
| |
| private Configuration conf; |
| private FileSystem fs; |
| private long interval; |
| |
| public Emptier(Configuration conf) throws IOException { |
| this.conf = conf; |
| this.interval = conf.getLong("fs.trash.interval", 60) * MSECS_PER_MINUTE; |
| this.fs = FileSystem.get(conf); |
| } |
| |
| public void run() { |
| if (interval == 0) |
| return; // trash disabled |
| |
| long now = System.currentTimeMillis(); |
| long end; |
| while (true) { |
| end = ceiling(now, interval); |
| try { // sleep for interval |
| Thread.sleep(end - now); |
| } catch (InterruptedException e) { |
| return; // exit on interrupt |
| } |
| |
| try { |
| now = System.currentTimeMillis(); |
| if (now >= end) { |
| |
| FileStatus[] homes = null; |
| try { |
| homes = fs.listStatus(HOMES); // list all home dirs |
| } catch (IOException e) { |
| LOG.warn("Trash can't list homes: "+e+" Sleeping."); |
| continue; |
| } |
| |
| if (homes == null) |
| continue; |
| |
| for (FileStatus home : homes) { // dump each trash |
| if (!home.isDir()) |
| continue; |
| try { |
| Trash trash = new Trash(home.getPath(), conf); |
| trash.expunge(); |
| trash.checkpoint(); |
| } catch (IOException e) { |
| LOG.warn("Trash caught: "+e+". Skipping "+home.getPath()+"."); |
| } |
| } |
| } |
| } catch (Exception e) { |
| LOG.warn("RuntimeException during Trash.Emptier.run() " + |
| StringUtils.stringifyException(e)); |
| } |
| } |
| } |
| |
| private long ceiling(long time, long interval) { |
| return floor(time, interval) + interval; |
| } |
| private long floor(long time, long interval) { |
| return (time / interval) * interval; |
| } |
| |
| } |
| |
| /** Run an emptier.*/ |
| public static void main(String[] args) throws Exception { |
| new Trash(new Configuration()).getEmptier().run(); |
| } |
| |
| } |