Package org.apache.hadoop.oncrpc

Class XDR

java.lang.Object

org.apache.hadoop.oncrpc.XDR

public final class XDR
extends java.lang.Object

Utility class for building XDR messages based on RFC 4506. Key points of the format:

• Primitives are stored in big-endian order (i.e., the default byte order of ByteBuffer).
• Booleans are stored as an integer.
• Each field in the message is always aligned by 4.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	XDR.State

Constructor Summary

Constructors

Constructor	Description
XDR()
XDR(byte[] src)	Wraps a byte array as a read-only XDR message.
XDR(int initialCapacity)	Construct a new XDR message buffer.
XDR(java.nio.ByteBuffer buf, XDR.State state)

Method Summary

Modifier and Type	Method	Description
XDR	asReadOnlyWrap()
java.nio.ByteBuffer	buffer()
static int	fragmentSize(byte[] mark)
byte[]	getBytes()
static boolean	isLastFragment(byte[] mark)
boolean	readBoolean()
byte[]	readFixedOpaque(int size)
long	readHyper()
int	readInt()
java.lang.String	readString()
byte[]	readVariableOpaque()
int	size()
static boolean	verifyLength(XDR xdr, int len)	check if the rest of data has more than len bytes.
void	writeBoolean(boolean v)
void	writeFixedOpaque(byte[] src)
void	writeFixedOpaque(byte[] src, int length)
void	writeInt(int v)
void	writeLongAsHyper(long v)
static io.netty.buffer.ByteBuf	writeMessageTcp(XDR request, boolean last)	Write an XDR message to a TCP ChannelBuffer.
static io.netty.buffer.ByteBuf	writeMessageUdp(XDR response)	Write an XDR message to a UDP ChannelBuffer.
void	writeString(java.lang.String s)
void	writeVariableOpaque(byte[] src)

Methods inherited from class java.lang.Object

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

Constructor Detail

XDR

public XDR(int initialCapacity)

Construct a new XDR message buffer.

Parameters:

initialCapacity - the initial capacity of the buffer.

XDR

public XDR()

XDR

public XDR(java.nio.ByteBuffer buf,
           XDR.State state)

XDR

public XDR(byte[] src)

Wraps a byte array as a read-only XDR message. There's no copy involved, thus it is the client's responsibility to ensure that the byte array remains unmodified when using the XDR object.

Parameters:

src - the byte array to be wrapped.

Method Detail

asReadOnlyWrap

public XDR asReadOnlyWrap()

buffer

public java.nio.ByteBuffer buffer()

size

public int size()

readInt

public int readInt()

writeInt

public void writeInt(int v)

readBoolean

public boolean readBoolean()

writeBoolean

public void writeBoolean(boolean v)

readHyper

public long readHyper()

writeLongAsHyper

public void writeLongAsHyper(long v)

readFixedOpaque

public byte[] readFixedOpaque(int size)

writeFixedOpaque

public void writeFixedOpaque(byte[] src,
                             int length)

writeFixedOpaque

public void writeFixedOpaque(byte[] src)

readVariableOpaque

public byte[] readVariableOpaque()

writeVariableOpaque

public void writeVariableOpaque(byte[] src)

readString

public java.lang.String readString()

writeString

public void writeString(java.lang.String s)

verifyLength

public static boolean verifyLength(XDR xdr,
                                   int len)

check if the rest of data has more than len bytes.

Parameters:

xdr - XDR message

len - minimum remaining length

Returns:

specify remaining length is enough or not

writeMessageTcp

public static io.netty.buffer.ByteBuf writeMessageTcp(XDR request,
                                                      boolean last)

Write an XDR message to a TCP ChannelBuffer.

Parameters:

request - XDR request

last - specifies last request or not

Returns:

TCP buffer

writeMessageUdp

public static io.netty.buffer.ByteBuf writeMessageUdp(XDR response)

Write an XDR message to a UDP ChannelBuffer.

Parameters:

response - XDR response

Returns:

UDP buffer

fragmentSize

public static int fragmentSize(byte[] mark)

isLastFragment

public static boolean isLastFragment(byte[] mark)

getBytes

@VisibleForTesting
public byte[] getBytes()