/**
    *
    * 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.hbase.mob.compactions;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.List;
  import java.util.concurrent.ExecutorService;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.mob.MobUtils;
  import org.apache.hadoop.hbase.util.FSUtils;
  
  /**
   * A mob compactor to directly compact the mob files.
   */
  @InterfaceAudience.Private
  public abstract class MobCompactor {
  
    protected FileSystem fs;
    protected Configuration conf;
    protected TableName tableName;
    protected HColumnDescriptor column;
  
    protected Path mobTableDir;
    protected Path mobFamilyDir;
    protected ExecutorService pool;
  
    public MobCompactor(Configuration conf, FileSystem fs, TableName tableName,
      HColumnDescriptor column, ExecutorService pool) {
      this.conf = conf;
      this.fs = fs;
      this.tableName = tableName;
      this.column = column;
      this.pool = pool;
      mobTableDir = FSUtils.getTableDir(MobUtils.getMobHome(conf), tableName);
      mobFamilyDir = MobUtils.getMobFamilyPath(conf, tableName, column.getNameAsString());
    }
  
    /**
     * Compacts the mob files for the current column family.
     * @return The paths of new mob files generated in the compaction.
     * @throws IOException
     */
    public List<Path> compact() throws IOException {
      return compact(false);
    }
  
    /**
     * Compacts the mob files by compaction type for the current column family.
     * @param allFiles Whether add all mob files into the compaction.
     * @return The paths of new mob files generated in the compaction.
     * @throws IOException
     */
    public List<Path> compact(boolean allFiles) throws IOException {
      return compact(Arrays.asList(fs.listStatus(mobFamilyDir)), allFiles);
    }
  
    /**
     * Compacts the candidate mob files.
     * @param files The candidate mob files.
     * @param allFiles Whether add all mob files into the compaction.
     * @return The paths of new mob files generated in the compaction.
     * @throws IOException
     */
    public abstract List<Path> compact(List<FileStatus> files, boolean allFiles)
      throws IOException;
  }