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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.fs;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_CHECKPOINT_INTERVAL_DEFAULT;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_CHECKPOINT_INTERVAL_KEY;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_DEFAULT;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_KEY;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Options.Rename;
import org.apache.hadoop.fs.permission.FsAction;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.util.Time;
/** Provides a trash feature. Files are moved to a user's trash
* directory, a subdirectory of their home directory named ".Trash". Files are
* initially moved to a current 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.)
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class TrashPolicyDefault extends TrashPolicy {
private static final Log LOG =
LogFactory.getLog(TrashPolicyDefault.class);
private static final Path CURRENT = new Path("Current");
private static final Path TRASH = new Path(".Trash/");
private static final FsPermission PERMISSION =
new FsPermission(FsAction.ALL, FsAction.NONE, FsAction.NONE);
private static final DateFormat CHECKPOINT = new SimpleDateFormat("yyMMddHHmmss");
/** Format of checkpoint directories used prior to Hadoop 0.23. */
private static final DateFormat OLD_CHECKPOINT =
new SimpleDateFormat("yyMMddHHmm");
private static final int MSECS_PER_MINUTE = 60*1000;
private Path current;
private Path homesParent;
private long emptierInterval;
public TrashPolicyDefault() { }
private TrashPolicyDefault(FileSystem fs, Path home, Configuration conf)
throws IOException {
initialize(conf, fs, home);
}
@Override
public void initialize(Configuration conf, FileSystem fs, Path home) {
this.fs = fs;
this.trash = new Path(home, TRASH);
this.homesParent = home.getParent();
this.current = new Path(trash, CURRENT);
this.deletionInterval = (long)(conf.getFloat(
FS_TRASH_INTERVAL_KEY, FS_TRASH_INTERVAL_DEFAULT)
* MSECS_PER_MINUTE);
this.emptierInterval = (long)(conf.getFloat(
FS_TRASH_CHECKPOINT_INTERVAL_KEY, FS_TRASH_CHECKPOINT_INTERVAL_DEFAULT)
* MSECS_PER_MINUTE);
LOG.info("Namenode trash configuration: Deletion interval = " +
(this.deletionInterval / MSECS_PER_MINUTE) + " minutes, Emptier interval = " +
(this.emptierInterval / MSECS_PER_MINUTE) + " minutes.");
}
private Path makeTrashRelativePath(Path basePath, Path rmFilePath) {
return Path.mergePaths(basePath, rmFilePath);
}
@Override
public boolean isEnabled() {
return deletionInterval != 0;
}
@SuppressWarnings("deprecation")
@Override
public boolean moveToTrash(Path path) throws IOException {
if (!isEnabled())
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 = fs.makeQualified(path).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, e);
cause = e;
break;
}
try {
// if the target path in Trash already exists, then append with
// a current time in millisecs.
String orig = trashPath.toString();
while(fs.exists(trashPath)) {
trashPath = new Path(orig + Time.now());
}
// move to current trash
fs.rename(path, trashPath,
Rename.TO_TRASH);
LOG.info("Moved: '" + path + "' to trash at: " + trashPath);
return true;
} catch (IOException e) {
cause = e;
}
}
throw (IOException)
new IOException("Failed to move to trash: "+path).initCause(cause);
}
@SuppressWarnings("deprecation")
@Override
public void createCheckpoint() throws IOException {
if (!fs.exists(current)) // no trash, no checkpoint
return;
Path checkpointBase;
synchronized (CHECKPOINT) {
checkpointBase = new Path(trash, CHECKPOINT.format(new Date()));
}
Path checkpoint = checkpointBase;
int attempt = 0;
while (true) {
try {
fs.rename(current, checkpoint, Rename.NONE);
break;
} catch (FileAlreadyExistsException e) {
if (++attempt > 1000) {
throw new IOException("Failed to checkpoint trash: "+checkpoint);
}
checkpoint = checkpointBase.suffix("-" + attempt);
}
}
LOG.info("Created trash checkpoint: "+checkpoint.toUri().getPath());
}
@Override
public void deleteCheckpoint() throws IOException {
FileStatus[] dirs = null;
try {
dirs = fs.listStatus(trash); // scan trash sub-directories
} catch (FileNotFoundException fnfe) {
return;
}
long now = Time.now();
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 {
time = getTimeFromCheckpoint(name);
} catch (ParseException e) {
LOG.warn("Unexpected item in trash: "+dir+". Ignoring.");
continue;
}
if ((now - deletionInterval) > time) {
if (fs.delete(path, true)) {
LOG.info("Deleted trash checkpoint: "+dir);
} else {
LOG.warn("Couldn't delete checkpoint: "+dir+" Ignoring.");
}
}
}
}
@Override
public Path getCurrentTrashDir() {
return current;
}
@Override
public Runnable getEmptier() throws IOException {
return new Emptier(getConf(), emptierInterval);
}
private class Emptier implements Runnable {
private Configuration conf;
private long emptierInterval;
Emptier(Configuration conf, long emptierInterval) throws IOException {
this.conf = conf;
this.emptierInterval = emptierInterval;
if (emptierInterval > deletionInterval || emptierInterval == 0) {
LOG.info("The configured checkpoint interval is " +
(emptierInterval / MSECS_PER_MINUTE) + " minutes." +
" Using an interval of " +
(deletionInterval / MSECS_PER_MINUTE) +
" minutes that is used for deletion instead");
this.emptierInterval = deletionInterval;
}
}
@Override
public void run() {
if (emptierInterval == 0)
return; // trash disabled
long now = Time.now();
long end;
while (true) {
end = ceiling(now, emptierInterval);
try { // sleep for interval
Thread.sleep(end - now);
} catch (InterruptedException e) {
break; // exit on interrupt
}
try {
now = Time.now();
if (now >= end) {
FileStatus[] homes = null;
try {
homes = fs.listStatus(homesParent); // list all home dirs
} catch (IOException e) {
LOG.warn("Trash can't list homes: "+e+" Sleeping.");
continue;
}
for (FileStatus home : homes) { // dump each trash
if (!home.isDirectory())
continue;
try {
TrashPolicyDefault trash = new TrashPolicyDefault(
fs, home.getPath(), conf);
trash.deleteCheckpoint();
trash.createCheckpoint();
} catch (IOException e) {
LOG.warn("Trash caught: "+e+". Skipping "+home.getPath()+".");
}
}
}
} catch (Exception e) {
LOG.warn("RuntimeException during Trash.Emptier.run(): ", e);
}
}
try {
fs.close();
} catch(IOException e) {
LOG.warn("Trash cannot close FileSystem: ", e);
}
}
private long ceiling(long time, long interval) {
return floor(time, interval) + interval;
}
private long floor(long time, long interval) {
return (time / interval) * interval;
}
}
private long getTimeFromCheckpoint(String name) throws ParseException {
long time;
try {
synchronized (CHECKPOINT) {
time = CHECKPOINT.parse(name).getTime();
}
} catch (ParseException pe) {
// Check for old-style checkpoint directories left over
// after an upgrade from Hadoop 1.x
synchronized (OLD_CHECKPOINT) {
time = OLD_CHECKPOINT.parse(name).getTime();
}
}
return time;
}
}
