content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.journal.checkpoint;
  
  import alluxio.RuntimeConstants;
  
  /**
   * Enumeration of different checkpoint types used by the master.
   */
  public enum CheckpointType {
    /**
     * This format sequentially writes delimited journal entries one after another using
     * the protocol buffer writeDelimitedTo method.
     */
    JOURNAL_ENTRY(0, new JournalCheckpointFormat()),
    /**
     * This format uses kryo's chunked encoding to write multiple [checkpoint_name, checkpoint_bytes]
     * entries to the output stream.
     */
    COMPOUND(1, new CompoundCheckpointFormat()),
    /**
     * A series of longs written by {@link java.io.DataOutputStream}.
     */
    LONGS(2, new LongsCheckpointFormat()),
    /**
     * A RocksDB backup in .tar.gz format with single thread.
     */
    ROCKS_SINGLE(3, new TarballCheckpointFormat()),
    /**
     * This format sequentially writes delimited InodeMeta.Inode protocol buffers one after another
     * using the protocol buffer writeDelimitedTo method.
     */
    INODE_PROTOS(4, new InodeProtosCheckpointFormat()),
    /**
     * A checkpoint consisting of a single long value written by a data output stream.
     */
    LONG(5, new LongCheckpointFormat()),
    /**
     * A RocksDB backup in .zip format with multi threads.
     */
    ROCKS_PARALLEL(6, new ZipCheckpointFormat());
  
    private final long mId;
    private final CheckpointFormat mCheckpointFormat;
  
    CheckpointType(long id, CheckpointFormat checkpointFormat) {
      mId = id;
      mCheckpointFormat = checkpointFormat;
    }
  
    /**
     * @return the checkpoint type's id
     */
    public long getId() {
      return mId;
    }
  
    /**
     * @return the checkpoint format
     */
    public CheckpointFormat getCheckpointFormat() {
      return mCheckpointFormat;
    }
  
    /**
     * @param id a checkpoint type id
     * @return the corresponding checkpoint type
     */
    public static CheckpointType fromLong(long id) {
      for (CheckpointType type : values()) {
        if (type.getId() == id) {
          return type;
        }
      }
      throw new IllegalStateException(String.format("Unknown checkpoint type id: %d. Was your "
          + "checkpoint written by alluxio-1.x? See %s for instructions on how to upgrade from "
          + "alluxio-1.x to alluxio-2.x", id, RuntimeConstants.ALLUXIO_2X_UPGRADE_DOC_URL));
    }
  }
  