org.apache.hadoop.fs.Trash.java Source code

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Here is the source code for org.apache.hadoop.fs.Trash.java

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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 java.io.IOException;

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.slf4j.Logger;
import org.slf4j.LoggerFactory;

/** 
 * Provides a trash facility which supports pluggable Trash policies. 
 *
 * See the implementation of the configured TrashPolicy for more
 * details.
 */
@InterfaceAudience.Public
@InterfaceStability.Stable
public class Trash extends Configured {
    private static final Logger LOG = LoggerFactory.getLogger(Trash.class);

    private TrashPolicy trashPolicy; // configured trash policy instance

    /** 
     * 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.
     * @param fs the FileSystem
     * @param conf a Configuration
     */
    public Trash(FileSystem fs, Configuration conf) throws IOException {
        super(conf);
        trashPolicy = TrashPolicy.getInstance(conf, fs);
    }

    /**
     * In case of the symlinks or mount points, one has to move the appropriate
     * trashbin in the actual volume of the path p being deleted.
     *
     * Hence we get the file system of the fully-qualified resolved-path and
     * then move the path p to the trashbin in that volume,
     * @param fs - the filesystem of path p
     * @param p - the  path being deleted - to be moved to trasg
     * @param conf - configuration
     * @return false if the item is already in the trash or trash is disabled
     * @throws IOException on error
     */
    public static boolean moveToAppropriateTrash(FileSystem fs, Path p, Configuration conf) throws IOException {
        Path fullyResolvedPath = fs.resolvePath(p);
        FileSystem fullyResolvedFs = FileSystem.get(fullyResolvedPath.toUri(), conf);
        // If the trash interval is configured server side then clobber this
        // configuration so that we always respect the server configuration.
        try {
            long trashInterval = fullyResolvedFs.getServerDefaults(fullyResolvedPath).getTrashInterval();
            if (0 != trashInterval) {
                Configuration confCopy = new Configuration(conf);
                confCopy.setLong(CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_KEY, trashInterval);
                conf = confCopy;
            }
        } catch (Exception e) {
            // If we can not determine that trash is enabled server side then
            // bail rather than potentially deleting a file when trash is enabled.
            LOG.warn("Failed to get server trash configuration", e);
            throw new IOException("Failed to get server trash configuration", e);
        }
        Trash trash = new Trash(fullyResolvedFs, conf);
        return trash.moveToTrash(fullyResolvedPath);
    }

    /**
     * Returns whether the trash is enabled for this filesystem
     */
    public boolean isEnabled() {
        return trashPolicy.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 boolean moveToTrash(Path path) throws IOException {
        return trashPolicy.moveToTrash(path);
    }

    /** Create a trash checkpoint. */
    public void checkpoint() throws IOException {
        trashPolicy.createCheckpoint();
    }

    /** Delete old checkpoint(s). */
    public void expunge() throws IOException {
        trashPolicy.deleteCheckpoint();
    }

    /** get the current working directory */
    Path getCurrentTrashDir() throws IOException {
        return trashPolicy.getCurrentTrashDir();
    }

    /** get the configured trash policy */
    TrashPolicy getTrashPolicy() {
        return trashPolicy;
    }

    /** Return a {@link Runnable} that periodically empties the trash of all
     * users, intended to be run by the superuser.
     */
    public Runnable getEmptier() throws IOException {
        return trashPolicy.getEmptier();
    }

    public Path getCurrentTrashDir(Path path) throws IOException {
        return trashPolicy.getCurrentTrashDir(path);
    }
}