org.apache.hadoop.hdfs.AddBlockFlag Maven / Gradle / Ivy
/**
* 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;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.CreateFlag;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import java.util.EnumSet;
/**
* AddBlockFlag provides hints for new block allocation and placement.
* Users can use this flag to control per DFSOutputStream
* @see ClientProtocol#addBlock(String, String, ExtendedBlock, DatanodeInfo[],
* long, String[], EnumSet)
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public enum AddBlockFlag {
/**
* Advise that a block replica NOT be written to the local DataNode where
* 'local' means the same host as the client is being run on.
*
* @see CreateFlag#NO_LOCAL_WRITE
*/
NO_LOCAL_WRITE((short) 0x01),
/**
* Advise that the first block replica NOT take into account DataNode
* locality. The first block replica should be placed randomly within the
* cluster. Subsequent block replicas should follow DataNode locality rules.
*
* @see CreateFlag#IGNORE_CLIENT_LOCALITY
*/
IGNORE_CLIENT_LOCALITY((short) 0x02),
/**
* Advise that a block replica NOT be written to the local rack DataNode where
* 'local' means the same host as the client is being run on.
*
* @see CreateFlag#NO_LOCAL_WRITE
*/
NO_LOCAL_RACK((short) 0x03);
private final short mode;
AddBlockFlag(short mode) {
this.mode = mode;
}
public static AddBlockFlag valueOf(short mode) {
for (AddBlockFlag flag : AddBlockFlag.values()) {
if (flag.getMode() == mode) {
return flag;
}
}
return null;
}
public short getMode() {
return mode;
}
}