org.apache.hadoop.fs.TrashPolicy Maven / Gradle / Ivy
/**
* 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 org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.util.ReflectionUtils;
import java.io.IOException;
/**
* This interface is used for implementing different Trash policies.
* Provides factory method to create instances of the configured Trash policy.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract class TrashPolicy extends Configured {
protected FileSystem fs; // the FileSystem
protected Path trash; // path to trash directory
protected long deletionInterval; // deletion interval for Emptier
/**
* Used to setup the trash policy. Must be implemented by all TrashPolicy
* implementations.
* @param conf the configuration to be used
* @param fs the filesystem to be used
* @param home the home directory
* @deprecated Use {@link #initialize(Configuration, FileSystem)} instead.
*/
@Deprecated
public abstract void initialize(Configuration conf, FileSystem fs, Path home);
/**
* Used to setup the trash policy. Must be implemented by all TrashPolicy
* implementations. Different from initialize(conf, fs, home), this one does
* not assume trash always under /user/$USER due to HDFS encryption zone.
* @param conf the configuration to be used
* @param fs the filesystem to be used
*/
public void initialize(Configuration conf, FileSystem fs) {
throw new UnsupportedOperationException();
}
/**
* Returns whether the Trash Policy is enabled for this filesystem.
*/
public abstract boolean isEnabled();
/**
* 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 abstract boolean moveToTrash(Path path) throws IOException;
/**
* Create a trash checkpoint.
*/
public abstract void createCheckpoint() throws IOException;
/**
* Delete old trash checkpoint(s).
*/
public abstract void deleteCheckpoint() throws IOException;
/**
* Delete all checkpoints immediately, ie empty trash.
*/
public abstract void deleteCheckpointsImmediately() throws IOException;
/**
* Get the current working directory of the Trash Policy
* This API does not work with files deleted from encryption zone when HDFS
* data encryption at rest feature is enabled as rename file between
* encryption zones or encryption zone and non-encryption zone is not allowed.
*
* The caller is recommend to use the new API
* TrashPolicy#getCurrentTrashDir(Path path).
* It returns the trash location correctly for the path specified no matter
* the path is in encryption zone or not.
*/
public abstract Path getCurrentTrashDir();
/**
* Get the current trash directory for path specified based on the Trash
* Policy
* @param path path to be deleted
* @return current trash directory for the path to be deleted
* @throws IOException
*/
public Path getCurrentTrashDir(Path path) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Return a {@link Runnable} that periodically empties the trash of all
* users, intended to be run by the superuser.
*/
public abstract Runnable getEmptier() throws IOException;
/**
* Get an instance of the configured TrashPolicy based on the value
* of the configuration parameter fs.trash.classname.
*
* @param conf the configuration to be used
* @param fs the file system to be used
* @param home the home directory
* @return an instance of TrashPolicy
* @deprecated Use {@link #getInstance(Configuration, FileSystem)} instead.
*/
@Deprecated
public static TrashPolicy getInstance(Configuration conf, FileSystem fs, Path home) {
Class trashClass = conf.getClass(
"fs.trash.classname", TrashPolicyDefault.class, TrashPolicy.class);
TrashPolicy trash = ReflectionUtils.newInstance(trashClass, conf);
trash.initialize(conf, fs, home); // initialize TrashPolicy
return trash;
}
/**
* Get an instance of the configured TrashPolicy based on the value
* of the configuration parameter fs.trash.classname.
*
* @param conf the configuration to be used
* @param fs the file system to be used
* @return an instance of TrashPolicy
*/
public static TrashPolicy getInstance(Configuration conf, FileSystem fs) {
Class trashClass = conf.getClass(
"fs.trash.classname", TrashPolicyDefault.class, TrashPolicy.class);
TrashPolicy trash = ReflectionUtils.newInstance(trashClass, conf);
trash.initialize(conf, fs); // initialize TrashPolicy
return trash;
}
}