Package org.apache.hadoop.hdfs.protocol.datatransfer

Class PacketReceiver

java.lang.Object

org.apache.hadoop.hdfs.protocol.datatransfer.PacketReceiver

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

@Private
public class PacketReceiver
extends java.lang.Object
implements java.io.Closeable

Class to handle reading packets one-at-a-time from the wire. These packets are used both for reading and writing data to/from DataNodes.

Field Summary

Fields

Modifier and Type	Field	Description
static int	MAX_PACKET_SIZE	The max size of any single packet.

Constructor Summary

Constructors

Constructor	Description
PacketReceiver(boolean useDirectBuffers)

Method Summary

Modifier and Type	Method	Description
void	close()
protected void	finalize()
java.nio.ByteBuffer	getChecksumSlice()
java.nio.ByteBuffer	getDataSlice()
PacketHeader	getHeader()
void	mirrorPacketTo(java.io.DataOutputStream mirrorOut)	Rewrite the last-read packet on the wire to the given output stream.
void	receiveNextPacket(java.io.InputStream in)
void	receiveNextPacket(java.nio.channels.ReadableByteChannel in)	Reads all of the data for the next packet into the appropriate buffers.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_PACKET_SIZE

public static final int MAX_PACKET_SIZE

The max size of any single packet. This prevents OOMEs when invalid data is sent.

Constructor Detail

PacketReceiver

public PacketReceiver(boolean useDirectBuffers)

Method Detail

getHeader

public PacketHeader getHeader()

getDataSlice

public java.nio.ByteBuffer getDataSlice()

getChecksumSlice

public java.nio.ByteBuffer getChecksumSlice()

receiveNextPacket

public void receiveNextPacket(java.nio.channels.ReadableByteChannel in)
                       throws java.io.IOException

Reads all of the data for the next packet into the appropriate buffers. The data slice and checksum slice members will be set to point to the user data and corresponding checksums. The header will be parsed and set.

Throws:

java.io.IOException

receiveNextPacket

public void receiveNextPacket(java.io.InputStream in)
                       throws java.io.IOException

Throws:

java.io.IOException

See Also:

receiveNextPacket(ReadableByteChannel)

mirrorPacketTo

public void mirrorPacketTo(java.io.DataOutputStream mirrorOut)
                    throws java.io.IOException

Rewrite the last-read packet on the wire to the given output stream.

Throws:

java.io.IOException

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable