001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.master.cleaner;
019
020import java.util.Map;
021import org.apache.hadoop.conf.Configurable;
022import org.apache.hadoop.fs.FileStatus;
023import org.apache.hadoop.fs.Path;
024import org.apache.hadoop.hbase.Stoppable;
025import org.apache.yetus.audience.InterfaceAudience;
026
027/**
028 * General interface for cleaning files from a folder (generally an archive or backup folder). These
029 * are chained via the {@link CleanerChore} to determine if a given file should be deleted.
030 */
031@InterfaceAudience.Private
032public interface FileCleanerDelegate extends Configurable, Stoppable {
033
034  /**
035   * Determines which of the given files are safe to delete
036   * <p>
037   * This method can be called concurrently by multiple threads. Implementations must be thread
038   * safe.
039   * </p>
040   * @param files files to check for deletion
041   * @return files that are ok to delete according to this cleaner
042   */
043  Iterable<FileStatus> getDeletableFiles(Iterable<FileStatus> files);
044
045  /**
046   * this method is used to pass some instance into subclass
047   */
048  void init(Map<String, Object> params);
049
050  /**
051   * Used to do some initialize work before every period clean
052   */
053  default void preClean() {
054  }
055
056  /**
057   * Will be called after cleaner run.
058   */
059  default void postClean() {
060  }
061
062  /**
063   * Check if a empty directory with no subdirs or subfiles can be deleted
064   * @param dir Path of the directory
065   * @return True if the directory can be deleted, otherwise false
066   */
067  default boolean isEmptyDirDeletable(Path dir) {
068    return true;
069  }
070}