org.jgroups.nio

Class WriteBuffers

java.lang.Object

org.jgroups.nio.Buffers

org.jgroups.nio.WriteBuffers

public class WriteBuffers
extends Buffers

Whereas Buffers only store 1 pending write, WriteBuffers store N pending writes. When the bounded buffer is full, additional writes will be discarded.

All pending writes are stored in the bufs array, and position and limit point to the current start and end of writable buffers.

Completed writes are nulled, and when the end of the array is reached, position and limit wrap around, possibly copying pending writes to the head of the array. Position and limit only advance when an entire buffer has been written successfully; partial writes don't advance them.

Like Buffers, WriteBuffers is not synchronized.

Invariant: 0 <= position <= limit

Since:

3.6.5

Author:

Bela Ban

Field Summary

Fields

Modifier and Type	Field and Description
protected int	limit
protected int	position

Fields inherited from class org.jgroups.nio.Buffers

bufs

Constructor Summary

Constructors

Constructor and Description
WriteBuffers()
WriteBuffers(java.nio.ByteBuffer data)
WriteBuffers(int capacity) Creates a WriteBuffers of capacity * 2 elements (capacity {length/data} pairs)

Method Summary

Modifier and Type	Method and Description
protected void	add(java.nio.ByteBuffer buf)
int	limit()
protected static java.nio.ByteBuffer	makeLengthBuffer(java.nio.ByteBuffer buf)
protected boolean	makeSpace()
protected boolean	nullData() Looks at all buffers in range [position ..
int	position()
java.lang.String	print()
int	remaining()
int	size() Returns the number of elements that have not yet been written
protected boolean	spaceAvailable()
java.lang.String	toString()
boolean	write(java.nio.channels.SocketChannel ch) Tries to complete a previous (unfinished) write
boolean	write(java.nio.channels.SocketChannel ch, java.nio.ByteBuffer buf) Writes the length and data with a gathering write

Methods inherited from class org.jgroups.nio.Buffers

nullData, read

Methods inherited from class java.lang.Object

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

Field Detail

position

protected int position

limit

protected int limit

Constructor Detail

WriteBuffers

public WriteBuffers()

WriteBuffers

public WriteBuffers(int capacity)

Creates a WriteBuffers of capacity * 2 elements (capacity {length/data} pairs)

WriteBuffers

public WriteBuffers(java.nio.ByteBuffer data)

Method Detail

position

public int position()

limit

public int limit()

write

public boolean write(java.nio.channels.SocketChannel ch,
                     java.nio.ByteBuffer buf)
              throws java.lang.Exception

Description copied from class: Buffers

Writes the length and data with a gathering write

Overrides:

write in class Buffers

Parameters:

ch - The channel to write to

buf - The data buffer. Note that Buffer.position needs to be at the start of the data to be written

Returns:

True if all the bytes of the buffer were written successfully, false otherwise.

Throws:

java.lang.Exception - Thrown if the write failed

write

public boolean write(java.nio.channels.SocketChannel ch)
              throws java.lang.Exception

Description copied from class: Buffers

Tries to complete a previous (unfinished) write

Overrides:

write in class Buffers

Parameters:

ch - The channel to write to

Returns:

True of all remaining bytes could be written, false otherwise

Throws:

java.lang.Exception - Thrown if the write failed

remaining

public int remaining()

Overrides:

remaining in class Buffers

size

public int size()

Returns the number of elements that have not yet been written

print

public java.lang.String print()

toString

public java.lang.String toString()

Overrides:

toString in class Buffers

spaceAvailable

protected boolean spaceAvailable()

makeSpace

protected boolean makeSpace()

add

protected void add(java.nio.ByteBuffer buf)

nullData

protected boolean nullData()

Looks at all buffers in range [position .. limit-1] and nulls buffers that have no remaining data. Returns true if all buffers could be nulled, and false otherwise

makeLengthBuffer

protected static java.nio.ByteBuffer makeLengthBuffer(java.nio.ByteBuffer buf)