| /** |
| * 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 |
| */ |
| public abstract void initialize(Configuration conf, FileSystem fs, Path home); |
| |
| /** |
| * 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; |
| |
| /** |
| * Get the current working directory of the Trash Policy |
| */ |
| public abstract Path getCurrentTrashDir(); |
| |
| /** |
| * 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 paramater 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 |
| */ |
| public static TrashPolicy getInstance(Configuration conf, FileSystem fs, Path home) |
| throws IOException { |
| Class<? extends TrashPolicy> trashClass = conf.getClass("fs.trash.classname", |
| TrashPolicyDefault.class, |
| TrashPolicy.class); |
| TrashPolicy trash = (TrashPolicy) ReflectionUtils.newInstance(trashClass, conf); |
| trash.initialize(conf, fs, home); // initialize TrashPolicy |
| return trash; |
| } |
| } |