alluxio.client.block.stream

Class NettyPacketWriter

java.lang.Object

alluxio.client.block.stream.NettyPacketWriter

All Implemented Interfaces:

PacketWriter, Cancelable, Closeable, AutoCloseable

@NotThreadSafe
public final class NettyPacketWriter
extends Object
implements PacketWriter

A netty packet writer that streams a full block or a UFS file to a netty data server. Protocol: 1. The client streams packets (start from pos 0) to the server. The client pauses if the client buffer is full, resumes if the buffer is not full. 2. The server reads packets from the channel and writes them to the block worker. See the server side implementation for details. 3. The client can either send an EOF packet or a CANCEL packet to end the write request. The client has to wait for the response from the data server for the EOF or CANCEL packet to make sure that the server has cleaned its states. 4. To make it simple to handle errors, the channel is closed if any error occurs. NOTE: this class is NOT threadsafe. Do not call cancel/close while some other threads are writing.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.client.block.stream.PacketWriter

PacketWriter.Factory

Method Summary

Modifier and Type	Method and Description
void	cancel() Cancels an operation.
void	close()
static NettyPacketWriter	create(FileSystemContext context, WorkerNetAddress address, long id, long length, Protocol.RequestType type, OutStreamOptions options)
void	flush() Flushes all the pending packets.
int	packetSize()
long	pos()
void	writePacket(io.netty.buffer.ByteBuf buf) Writes a packet.

Methods inherited from class java.lang.Object

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

Method Detail

create

public static NettyPacketWriter create(FileSystemContext context,
                                       WorkerNetAddress address,
                                       long id,
                                       long length,
                                       Protocol.RequestType type,
                                       OutStreamOptions options)
                                throws IOException

Parameters:

context - the file system context

address - the data server address

id - the block or UFS ID

length - the length of the block or file to write, set to Long.MAX_VALUE if unknown

type - type of the write request

options - the options of the output stream

Returns:

an instance of NettyPacketWriter

Throws:

IOException

pos

public long pos()

Specified by:

pos in interface PacketWriter

Returns:

the current pos which is the same as the totally number of bytes written so far

writePacket

public void writePacket(io.netty.buffer.ByteBuf buf)
                 throws IOException

Description copied from interface: PacketWriter

Writes a packet. This method takes the ownership of this packet even if it fails to write the packet.

Specified by:

writePacket in interface PacketWriter

Parameters:

buf - the packet

Throws:

IOException

cancel

public void cancel()

Description copied from interface: Cancelable

Cancels an operation.

Specified by:

cancel in interface Cancelable

flush

public void flush()
           throws IOException

Description copied from interface: PacketWriter

Flushes all the pending packets.

Specified by:

flush in interface PacketWriter

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

packetSize

public int packetSize()

Specified by:

packetSize in interface PacketWriter

Returns:

the packet size in bytes used