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

Class MappableBlockLoader

java.lang.Object

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

Direct Known Subclasses:

MemoryMappableBlockLoader, PmemMappableBlockLoader

@Private
@Unstable
public abstract class MappableBlockLoader
extends Object

Maps block to DataNode cache region.

Constructor Summary

Constructors

Constructor	Description
MappableBlockLoader()

Method Summary

Modifier and Type	Method	Description
protected int	fillBuffer(FileChannel channel, ByteBuffer buf)	Reads bytes into a buffer until EOF or the buffer's limit is reached.
protected void	verifyChecksum(long length, FileInputStream metaIn, FileChannel blockChannel, String blockFileName)	Verifies the block's checksum.

Methods inherited from class java.lang.Object

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

Constructor Details

MappableBlockLoader

public MappableBlockLoader()

Method Details

verifyChecksum

protected void verifyChecksum(long length,
 FileInputStream metaIn,
 FileChannel blockChannel,
 String blockFileName)
                       throws IOException

Verifies the block's checksum. This is an I/O intensive operation.

Throws:

IOException

fillBuffer

protected int fillBuffer(FileChannel channel,
 ByteBuffer buf)
                  throws IOException

Reads bytes into a buffer until EOF or the buffer's limit is reached.

Throws:

IOException