jcsp.util.ints
Class OverWriteOldestBufferInt

java.lang.Object
  |
  +--jcsp.util.ints.OverWriteOldestBufferInt

All Implemented Interfaces:

ChannelDataStoreInt, Cloneable, Serializable

public class OverWriteOldestBufferInt

extends Object

implements ChannelDataStoreInt, Serializable

This is used to create a buffered integer channel that always accepts input, overwriting its oldest data if full.

Description

OverWriteOldestBufferInt is an implementation of ChannelDataStoreInt that yields a FIFO buffered semantics for a channel. When empty, the channel blocks readers. When full, a writer will overwrite the oldest item left unread in the channel. See the static create methods of One2OneChannelInt etc.

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

Author:

P.D.Austin

See Also:

ZeroBufferInt, BufferInt, OverWritingBufferInt, OverFlowingBufferInt, InfiniteBufferInt, One2OneChannelInt, Any2OneChannelInt, One2AnyChannelInt, Any2AnyChannelInt, Serialized Form

Fields inherited from interface jcsp.util.ints.ChannelDataStoreInt

EMPTY, FULL, NONEMPTYFULL

Constructor Summary

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

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

OverWriteOldestBufferInt

public OverWriteOldestBufferInt(int size)

Construct a new OverWriteOldestBufferInt with the specified size.

Parameters:

size - the number of ints the OverWriteOldestBufferInt can store.

Throws:

BufferIntSizeError - 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 int get()

Returns the oldest int from the OverWriteOldestBufferInt and removes it.

Pre-condition: getState must not currently return EMPTY.

Specified by:

get in interface ChannelDataStoreInt

Returns:

the oldest int from the OverWriteOldestBufferInt

put

public void put(int value)

Puts a new int into the OverWriteOldestBufferInt.

If OverWriteOldestBufferInt is full, the oldest item left unread in the buffer will be overwritten.

Specified by:

put in interface ChannelDataStoreInt

Parameters:

value - the int to put into the OverWriteOldestBufferInt

getState

public int getState()

Returns the current state of the OverWriteOldestBufferInt.

Specified by:

getState in interface ChannelDataStoreInt

Returns:

the current state of the OverWriteOldestBufferInt (EMPTY or NONEMPTYFULL)

clone

public Object clone()

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

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

Specified by:

clone in interface ChannelDataStoreInt

Overrides:

clone in class Object

Returns:

the cloned instance of this OverWriteOldestBufferInt.