org.apache.hadoop.hdfs.server.protocol

类 BlockCommand

java.lang.Object

org.apache.hadoop.hdfs.server.protocol.DatanodeCommand

org.apache.hadoop.hdfs.server.protocol.BlockCommand

所有已实现的接口:

Writable

public class BlockCommand
extends DatanodeCommand

A BlockCommand is an instruction to a datanode regarding some blocks under its control. It tells the DataNode to either invalidate a set of indicated blocks, or to copy a set of indicated blocks to another DataNode.

字段概要

从类继承的字段 org.apache.hadoop.hdfs.server.protocol.DatanodeCommand

FINALIZE, REGISTER

构造器概要

构造器

构造器和说明
BlockCommand()
BlockCommand(int action, Block[] blocks) Create BlockCommand for the given action
BlockCommand(int action, List<DatanodeDescriptor.BlockTargetPair> blocktargetlist) Create BlockCommand for transferring blocks to another datanode

方法概要

方法

限定符和类型	方法和说明
Block[]	getBlocks()
DatanodeInfo[][]	getTargets()
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	write(DataOutput out) Serialize the fields of this object to out.

从类继承的方法 org.apache.hadoop.hdfs.server.protocol.DatanodeCommand

getAction

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

BlockCommand

public BlockCommand()

BlockCommand

public BlockCommand(int action,
            List<DatanodeDescriptor.BlockTargetPair> blocktargetlist)

Create BlockCommand for transferring blocks to another datanode

参数:

blocktargetlist - blocks to be transferred

BlockCommand

public BlockCommand(int action,
            Block[] blocks)

Create BlockCommand for the given action

参数:

blocks - blocks related to the action

方法详细资料

getBlocks

public Block[] getBlocks()

getTargets

public DatanodeInfo[][] getTargets()

write

public void write(DataOutput out)
           throws IOException

从接口复制的说明: Writable

Serialize the fields of this object to out.

指定者:

write 在接口中 Writable

覆盖:

write 在类中 DatanodeCommand

参数:

out - DataOuput to serialize this object into.

抛出:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

从接口复制的说明: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

指定者:

readFields 在接口中 Writable

覆盖:

readFields 在类中 DatanodeCommand

参数:

in - DataInput to deseriablize this object from.

抛出:

IOException