Package edu.rit.mp.buf

Class ByteItemBuf

java.lang.Object

edu.rit.mp.Buf

edu.rit.mp.ByteBuf

edu.rit.mp.buf.ByteItemBuf

public class ByteItemBuf
extends ByteBuf

Class ByteItemBuf provides a buffer for a single byte item sent or received using the Message Protocol (MP). While an instance of class ByteItemBuf may be constructed directly, normally you will use a factory method in class ByteBuf. See that class for further information.

Version:

25-Oct-2007

Author:

Alan Kaminsky

Field Summary

Fields

Modifier and Type	Field	Description
byte	item	Byte item to be sent or received.

Fields inherited from class edu.rit.mp.Buf

myLength

Constructor Summary

Constructors

Constructor	Description
ByteItemBuf()	Construct a new byte item buffer.
ByteItemBuf(byte item)	Construct a new byte item buffer with the given initial value.

Method Summary

Modifier and Type	Method	Description
byte	get(int i)	Obtain the given item from this buffer.
Buf	getReductionBuf(Op op)	Create a buffer for performing parallel reduction using the given binary operation.
void	put(int i, byte item)	Store the given item in this buffer.
protected int	receiveItems(int i, int num, ByteBuffer buffer)	Receive as many items as possible from the given byte buffer to this buffer.
protected int	sendItems(int i, ByteBuffer buffer)	Send as many items as possible from this buffer to the given byte buffer.

Methods inherited from class edu.rit.mp.ByteBuf

buffer, buffer, buffer, buffer, buffer, buffer, colSliceBuffer, colSliceBuffers, copy, defaultCopy, emptyBuffer, fill, getTemporaryBuf, patchBuffer, patchBuffers, rowSliceBuffer, rowSliceBuffers, sliceBuffer, sliceBuffer, sliceBuffers, sliceBuffers

Methods inherited from class edu.rit.mp.Buf

length

Methods inherited from class java.lang.Object

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

Field Details

item

public byte item

Byte item to be sent or received.

Constructor Details

ByteItemBuf

public ByteItemBuf()

Construct a new byte item buffer.

ByteItemBuf

public ByteItemBuf(byte item)

Construct a new byte item buffer with the given initial value.

Parameters:

item - Initial value of the item field.

Method Details

get

public byte get(int i)

Obtain the given item from this buffer.

The get() method must not block the calling thread; if it does, all message I/O in MP will be blocked. Obtain the given item from this buffer.

The get() method must not block the calling thread; if it does, all message I/O in MP will be blocked.

Specified by:

get in class ByteBuf

Parameters:

i - Item index in the range 0 .. length()-1.

Returns:

Item at index i.

put

public void put(int i,
 byte item)

Store the given item in this buffer.

The put() method must not block the calling thread; if it does, all message I/O in MP will be blocked. Store the given item in this buffer.

The put() method must not block the calling thread; if it does, all message I/O in MP will be blocked.

Specified by:

put in class ByteBuf

Parameters:

i - Item index in the range 0 .. length()-1.

item - Item to be stored at index i.

getReductionBuf

public Buf getReductionBuf(Op op)

Create a buffer for performing parallel reduction using the given binary operation. The results of the reduction are placed into this buffer.

Operations performed on the returned reduction buffer have the same effect as operations performed on this buffer, except whenever a source item S is put into a destination item D in this buffer, D is set to D op S, that is, the reduction of D and S using the given binary operation (rather than just setting D to S). Create a buffer for performing parallel reduction using the given binary operation. The results of the reduction are placed into this buffer.

Specified by:

getReductionBuf in class Buf

Parameters:

op - Binary operation.

Returns:

a Buf object.

Throws:

ClassCastException - (unchecked exception) Thrown if this buffer's element data type and the given binary operation's argument data type are not the same.

sendItems

protected int sendItems(int i,
 ByteBuffer buffer)

Send as many items as possible from this buffer to the given byte buffer.

The sendItems() method must not block the calling thread; if it does, all message I/O in MP will be blocked. Send as many items as possible from this buffer to the given byte buffer.

The sendItems() method must not block the calling thread; if it does, all message I/O in MP will be blocked.

Specified by:

sendItems in class Buf

Parameters:

i - Index of first item to send, in the range 0 .. length-1.

buffer - Byte buffer.

Returns:

Number of items sent.

receiveItems

protected int receiveItems(int i,
 int num,
 ByteBuffer buffer)

Receive as many items as possible from the given byte buffer to this buffer.

The receiveItems() method must not block the calling thread; if it does, all message I/O in MP will be blocked. Receive as many items as possible from the given byte buffer to this buffer.

The receiveItems() method must not block the calling thread; if it does, all message I/O in MP will be blocked.

Specified by:

receiveItems in class Buf

Parameters:

i - Index of first item to receive, in the range 0 .. length-1.

num - Maximum number of items to receive.

buffer - Byte buffer.

Returns:

Number of items received.