alluxio.worker.block

Class RemoteBlockReader

java.lang.Object

alluxio.worker.block.io.BlockClient

alluxio.worker.block.io.BlockReader

alluxio.worker.block.RemoteBlockReader

All Implemented Interfaces:

Closeable, AutoCloseable

public class RemoteBlockReader
extends BlockReader

Reads a block from a remote worker node. This should only be used for reading entire blocks.

Nested Class Summary

Nested classes/interfaces inherited from class alluxio.worker.block.io.BlockClient

BlockClient.Type

Constructor Summary

Constructors

Constructor and Description
RemoteBlockReader(FileSystemContext fsContext, long blockId, long blockSize, InetSocketAddress dataSource, Protocol.OpenUfsBlockOptions ufsOptions) Constructs a remote block reader.

Method Summary

Modifier and Type	Method and Description
void	close()
ReadableByteChannel	getChannel() Returns a readable byte channel of the block.
long	getLength() Gets the length of the block in bytes.
String	getLocation()
boolean	isClosed()
ByteBuffer	read(long offset, long length) Reads data from the block.
int	transferTo(io.netty.buffer.ByteBuf buf) Transfers data (up to buf.writableBytes()) from this reader to the buffer.

Methods inherited from class alluxio.worker.block.io.BlockClient

toString

Methods inherited from class java.lang.Object

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

Constructor Detail

RemoteBlockReader

public RemoteBlockReader(FileSystemContext fsContext,
                         long blockId,
                         long blockSize,
                         InetSocketAddress dataSource,
                         Protocol.OpenUfsBlockOptions ufsOptions)

Constructs a remote block reader. It will read from a remote worker based on the data source.

Parameters:

fsContext - the filesystem context to use to create BlockInStream

blockId - the block to cache

blockSize - the size of the block

dataSource - the data source to cache from

ufsOptions - the options to read the block from ufs if necessary

Method Detail

read

public ByteBuffer read(long offset,
                       long length)
                throws IOException

Description copied from class: BlockReader

Reads data from the block.

Specified by:

read in class BlockReader

Parameters:

offset - the offset from starting of the block file in bytes

length - the length of data to read in bytes

Returns:

ByteBuffer the data that was read

Throws:

IOException

getLength

public long getLength()

Description copied from class: BlockReader

Gets the length of the block in bytes.

Specified by:

getLength in class BlockReader

Returns:

the length of the block in bytes

getChannel

public ReadableByteChannel getChannel()

Description copied from class: BlockReader

Returns a readable byte channel of the block.

Specified by:

getChannel in class BlockReader

Returns:

channel

transferTo

public int transferTo(io.netty.buffer.ByteBuf buf)
               throws IOException

Description copied from class: BlockReader

Transfers data (up to buf.writableBytes()) from this reader to the buffer.

Specified by:

transferTo in class BlockReader

Parameters:

buf - the byte buffer

Returns:

the number of bytes transferred, -1 if the end of the block is reached

Throws:

IOException

isClosed

public boolean isClosed()

Specified by:

isClosed in class BlockReader

Returns:

true if this reader is closed

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class BlockClient

Throws:

IOException

getLocation

public String getLocation()

Specified by:

getLocation in class BlockReader

Returns:

an informational string of the location the reader is reading from