hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ReconfigurationProtocolServerSideTranslatorPB.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.protocolPB;

import java.io.IOException;

import org.apache.hadoop.hdfs.protocol.ReconfigurationProtocol;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.GetReconfigurationStatusRequestProto;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.GetReconfigurationStatusResponseProto;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.ListReconfigurablePropertiesRequestProto;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.ListReconfigurablePropertiesResponseProto;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.StartReconfigurationRequestProto;
import org.apache.hadoop.hdfs.protocol.proto.ReconfigurationProtocolProtos.StartReconfigurationResponseProto;

import org.apache.hadoop.thirdparty.protobuf.RpcController;
import org.apache.hadoop.thirdparty.protobuf.ServiceException;

/**
 * This class is used on the server side. Calls come across the wire for the
 * for protocol {@link ReconfigurationProtocolPB}.
 * This class translates the PB data types
 * to the native data types used inside the NN/DN as specified in the generic
 * ReconfigurationProtocol.
 */
public class ReconfigurationProtocolServerSideTranslatorPB implements
    ReconfigurationProtocolPB {

  private final ReconfigurationProtocol impl;

  private static final StartReconfigurationResponseProto START_RECONFIG_RESP =
      StartReconfigurationResponseProto.newBuilder().build();

  public ReconfigurationProtocolServerSideTranslatorPB(
      ReconfigurationProtocol impl) {
    this.impl = impl;
  }

  @Override
  public StartReconfigurationResponseProto startReconfiguration(
      RpcController controller, StartReconfigurationRequestProto request)
      throws ServiceException {
    try {
      impl.startReconfiguration();
    } catch (IOException e) {
      throw new ServiceException(e);
    }
    return START_RECONFIG_RESP;
  }

  @Override
  public ListReconfigurablePropertiesResponseProto listReconfigurableProperties(
      RpcController controller,
      ListReconfigurablePropertiesRequestProto request)
      throws ServiceException {
    try {
      return ReconfigurationProtocolServerSideUtils
          .listReconfigurableProperties(impl.listReconfigurableProperties());
    } catch (IOException e) {
      throw new ServiceException(e);
    }
  }

  @Override
  public GetReconfigurationStatusResponseProto getReconfigurationStatus(
      RpcController unused, GetReconfigurationStatusRequestProto request)
      throws ServiceException {
    try {
      return ReconfigurationProtocolServerSideUtils
          .getReconfigurationStatus(impl.getReconfigurationStatus());
    } catch (IOException e) {
      throw new ServiceException(e);
    }
  }
}