branch-2.0.4-alpha/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/BlockConstructionStage.java

/**
 * 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.hdfs.protocol.datatransfer;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;

/** Block Construction Stage */
@InterfaceAudience.Private
@InterfaceStability.Evolving
public enum BlockConstructionStage {
  /** The enumerates are always listed as regular stage followed by the
   * recovery stage. 
   * Changing this order will make getRecoveryStage not working.
   */
  // pipeline set up for block append
  PIPELINE_SETUP_APPEND,
  // pipeline set up for failed PIPELINE_SETUP_APPEND recovery
  PIPELINE_SETUP_APPEND_RECOVERY,
  // data streaming
  DATA_STREAMING,
  // pipeline setup for failed data streaming recovery
  PIPELINE_SETUP_STREAMING_RECOVERY,
  // close the block and pipeline
  PIPELINE_CLOSE,
  // Recover a failed PIPELINE_CLOSE
  PIPELINE_CLOSE_RECOVERY,
  // pipeline set up for block creation
  PIPELINE_SETUP_CREATE,
  // transfer RBW for adding datanodes
  TRANSFER_RBW,
  // transfer Finalized for adding datanodes
  TRANSFER_FINALIZED;
  
  final static private byte RECOVERY_BIT = (byte)1;
  
  /**
   * get the recovery stage of this stage
   */
  public BlockConstructionStage getRecoveryStage() {
    if (this == PIPELINE_SETUP_CREATE) {
      throw new IllegalArgumentException( "Unexpected blockStage " + this);
    } else {
      return values()[ordinal()|RECOVERY_BIT];
    }
  }
}