Package org.apache.hadoop.hdfs.server.datanode.fsdataset.impl

Class MemoryMappedBlock

java.lang.Object

org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.MemoryMappedBlock

All Implemented Interfaces:

Closeable, AutoCloseable, MappableBlock

@Private
@Unstable
public class MemoryMappedBlock
extends Object
implements MappableBlock

Represents an HDFS block that is mapped to memory by the DataNode.

Method Summary

Modifier and Type	Method	Description
void	close()
long	getAddress()	Get cache address if applicable.
org.apache.hadoop.hdfs.ExtendedBlockId	getKey()	Get cached block's ExtendedBlockId.
long	getLength()	Get the number of bytes that have been cached.

Methods inherited from class java.lang.Object

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

Method Details

getLength

public long getLength()

Description copied from interface: MappableBlock

Get the number of bytes that have been cached.

Specified by:

getLength in interface MappableBlock

Returns:

the number of bytes that have been cached.

getAddress

public long getAddress()

Description copied from interface: MappableBlock

Get cache address if applicable. Return -1 if not applicable.

Specified by:

getAddress in interface MappableBlock

getKey

public org.apache.hadoop.hdfs.ExtendedBlockId getKey()

Description copied from interface: MappableBlock

Get cached block's ExtendedBlockId.

Specified by:

getKey in interface MappableBlock

Returns:

cached block's ExtendedBlockId..

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable