/**
* 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;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.ipc.VersionedProtocol;
/** An client-datanode protocol for block recovery
*/
public interface ClientDatanodeProtocol extends VersionedProtocol {
public static final Log LOG = LogFactory.getLog(ClientDatanodeProtocol.class);
/**
* 3: add keepLength parameter.
*/
public static final long versionID = 3L;
/** Start generation-stamp recovery for specified block
* @param block the specified block
* @param keepLength keep the block length
* @param targets the list of possible locations of specified block
* @return the new blockid if recovery successful and the generation stamp
* got updated as part of the recovery, else returns null if the block id
* not have any data and the block was deleted.
* @throws IOException
*/
LocatedBlock recoverBlock(Block block, boolean keepLength,
DatanodeInfo[] targets) throws IOException;
}