jcsp.util
Class OverFlowingBuffer

java.lang.Object
  |
  +--jcsp.util.OverFlowingBuffer

All Implemented Interfaces:

ChannelDataStore, Cloneable, Serializable

public class OverFlowingBuffer

extends Object

implements ChannelDataStore, Serializable

This is used to create a buffered object channel that always accepts input, discarding its last entered data if full.

Description

It is an implementation of ChannelDataStore that yields a FIFO buffered semantics for a channel. When empty, the channel blocks readers. When full, a writer will be accepted but the written value overflows the buffer and is lost to the channel. See the static create methods of One2OneChannel etc.

The getState method returns EMPTY or NONEMPTYFULL, but never FULL.

Author:

P.D.Austin

See Also:

ZeroBuffer, Buffer, OverWriteOldestBuffer, OverWritingBuffer, InfiniteBuffer, One2OneChannel, Any2OneChannel, One2AnyChannel, Any2AnyChannel, Serialized Form

Fields inherited from interface jcsp.util.ChannelDataStore

EMPTY, FULL, NONEMPTYFULL

Constructor Summary

OverFlowingBuffer(int size)
Construct a new OverFlowingBuffer with the specified size.

Method Summary

Object	clone() Returns a new (and EMPTY) OverFlowingBuffer with the same creation parameters as this one.
Object	get() Returns the oldest Object from the OverFlowingBuffer and removes it.
int	getState() Returns the current state of the OverFlowingBuffer.
void	put(Object value) Puts a new Object into the OverFlowingBuffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

OverFlowingBuffer

public OverFlowingBuffer(int size)

Construct a new OverFlowingBuffer with the specified size.

Parameters:

size - the number of Objects the OverFlowingBuffer can store.

Throws:

BufferSizeError - if size is zero or negative. Note: no action should be taken to try/catch this exception - application code generating it is in error and needs correcting.

Method Detail

get

public Object get()

Returns the oldest Object from the OverFlowingBuffer and removes it.

Pre-condition: getState must not currently return EMPTY.

Specified by:

get in interface ChannelDataStore

Returns:

the oldest Object from the OverFlowingBuffer

put

public void put(Object value)

Puts a new Object into the OverFlowingBuffer.

If OverFlowingBuffer is full, the item is discarded.

Specified by:

put in interface ChannelDataStore

Parameters:

value - the Object to put into the OverFlowingBuffer

getState

public int getState()

Returns the current state of the OverFlowingBuffer.

Specified by:

getState in interface ChannelDataStore

Returns:

the current state of the OverFlowingBuffer (EMPTY or NONEMPTYFULL)

clone

public Object clone()

Returns a new (and EMPTY) OverFlowingBuffer with the same creation parameters as this one.

Note: Only the size and structure of the OverFlowingBuffer is cloned, not any stored data.

Specified by:

clone in interface ChannelDataStore

Overrides:

clone in class Object

Returns:

the cloned instance of this OverFlowingBuffer.