org.jcsp.util.ints

Class InfiniteBufferInt

java.lang.Object

org.jcsp.util.ints.InfiniteBufferInt

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, ChannelDataStoreInt

public class InfiniteBufferInt
extends java.lang.Object
implements ChannelDataStoreInt, java.io.Serializable

This is used to create a buffered integer channel that always accepts and never loses any input.

Description

InfiniteBufferInt is an implementation of ChannelDataStoreInt that yields a FIFO buffered semantics for a channel. When empty, the channel blocks readers. However, its capacity is infinite (expanding to whatever is needed so far as the underlying memory system will permit). So, it never gets full and blocks a writer. See the static construction methods of Channel (Channel.one2oneInt(org.jcsp.util.ints.ChannelDataStoreInt) etc.).

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

An initial size for the buffer can be specified during construction.

See Also:

ZeroBufferInt, BufferInt, OverWriteOldestBufferInt, OverWritingBufferInt, OverFlowingBufferInt, ChannelInt, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private int[]	buffer The storage for the buffered ints
private int	counter The number of ints stored in the InfiniteBufferInt
private static int	DEFAULT_SIZE The default size of the buffer
private int	firstIndex The index of the oldest element (when counter > 0)
private int	initialSize The initial size of the buffer
private int	lastIndex The index of the next free element (when counter < buffer.length)

Fields inherited from interface org.jcsp.util.ints.ChannelDataStoreInt

EMPTY, FULL, NONEMPTYFULL

Constructor Summary

Constructors

Constructor and Description
InfiniteBufferInt() Construct a new InfiniteBufferInt with the default size (of 8).
InfiniteBufferInt(int initialSize) Construct a new InfiniteBufferInt with the specified initial size.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone() Returns a new (and EMPTY) InfiniteBufferInt with the same creation parameters as this one.
void	endGet() Removes the oldest integer from the buffer.
int	get() Returns the oldest int from the InfiniteBufferInt and removes it.
int	getState() Returns the current state of the InfiniteBufferInt.
void	put(int value) Puts a new int into the InfiniteBufferInt.
void	removeAll()
int	startGet() Returns the oldest integer from the buffer but does not remove it.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SIZE

private static final int DEFAULT_SIZE

The default size of the buffer

See Also:

Constant Field Values

initialSize

private int initialSize

The initial size of the buffer

buffer

private int[] buffer

The storage for the buffered ints

counter

private int counter

The number of ints stored in the InfiniteBufferInt

firstIndex

private int firstIndex

The index of the oldest element (when counter > 0)

lastIndex

private int lastIndex

The index of the next free element (when counter < buffer.length)

Constructor Detail

InfiniteBufferInt

public InfiniteBufferInt()

Construct a new InfiniteBufferInt with the default size (of 8).

InfiniteBufferInt

public InfiniteBufferInt(int initialSize)

Construct a new InfiniteBufferInt with the specified initial size.

Parameters:

initialSize - the number of ints the InfiniteBufferInt can initially store.

Throws:

BufferIntSizeError - if initialSize 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 InfiniteBufferInt and removes it.

Pre-condition: getState must not currently return EMPTY.

Specified by:

get in interface ChannelDataStoreInt

Returns:

the oldest int from the InfiniteBufferInt

startGet

public int startGet()

Returns the oldest integer from the buffer but does not remove it. Pre-condition: getState must not currently return EMPTY.

Specified by:

startGet in interface ChannelDataStoreInt

Returns:

the oldest int from the Buffer

See Also:

ChannelDataStoreInt.endGet()

endGet

public void endGet()

Removes the oldest integer from the buffer.

Specified by:

endGet in interface ChannelDataStoreInt

See Also:

ChannelDataStoreInt.startGet()

put

public void put(int value)

Puts a new int into the InfiniteBufferInt.

Implementation note: if InfiniteBufferInt is full, a new internal buffer with double the capacity is constructed and the old data copied across.

Specified by:

put in interface ChannelDataStoreInt

Parameters:

value - the int to put into the InfiniteBufferInt

getState

public int getState()

Returns the current state of the InfiniteBufferInt.

Specified by:

getState in interface ChannelDataStoreInt

Returns:

the current state of the InfiniteBufferInt (EMPTY or NONEMPTYFULL)

clone

public java.lang.Object clone()

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

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

Specified by:

clone in interface ChannelDataStoreInt

Overrides:

clone in class java.lang.Object

Returns:

the cloned instance of this InfiniteBufferInt.

removeAll

public void removeAll()

Specified by:

removeAll in interface ChannelDataStoreInt