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

Class PacketReceiver

java.lang.Object

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

All Implemented Interfaces:

Closeable, AutoCloseable

@Private
public class PacketReceiver
extends Object
implements 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 final 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()
ByteBuffer	getChecksumSlice()
ByteBuffer	getDataSlice()
PacketHeader	getHeader()
void	mirrorPacketTo(DataOutputStream mirrorOut)	Rewrite the last-read packet on the wire to the given output stream.
void	receiveNextPacket(InputStream in)
void	receiveNextPacket(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 Details

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 Details

PacketReceiver

public PacketReceiver(boolean useDirectBuffers)

Method Details

getHeader

public PacketHeader getHeader()

getDataSlice

public ByteBuffer getDataSlice()

getChecksumSlice

public ByteBuffer getChecksumSlice()

receiveNextPacket

public void receiveNextPacket(ReadableByteChannel in)
                       throws 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:

IOException

receiveNextPacket

public void receiveNextPacket(InputStream in)
                       throws IOException

Throws:

IOException

See Also:

• receiveNextPacket(ReadableByteChannel)

mirrorPacketTo

public void mirrorPacketTo(DataOutputStream mirrorOut)
                    throws IOException

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

Throws:

IOException

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable