com.gargoylesoftware.base.trace
Class BlockingCircularQueue

java.lang.Object
  com.gargoylesoftware.base.trace.BlockingCircularQueue

All Implemented Interfaces:

java.io.Serializable

public class BlockingCircularQueue
extends java.lang.Object
implements java.io.Serializable

Internal use only.

.

A circular queue with blocking semantics.

Version:

$Revision: 1.9 $

Author:

Mike Bowler

See Also:

Serialized Form

Field Summary

private java.lang.Object	addLock_
private int	back_
private int	capacity_
private int	front_
private java.lang.Object	getLock_
private java.lang.Object[]	queue_
private static long	serialVersionUID
private int	size_

Constructor Summary

BlockingCircularQueue()
Create the queue with a capacity of 20

BlockingCircularQueue(int capacity)
Create the queue with the specified capacity

Method Summary

boolean	add(java.lang.Object object) Add an object to the queue.
protected void	assertNotNull(java.lang.String fieldName, java.lang.Object fieldValue) Verify that the specified value is not null.
void	clear() Remove all items from the queue
private int	incrementPosition(int position) Utility method to increment the position and roll back to zero once we hit the end.
boolean	isEmpty() Return true if the collection is empty.
java.lang.Object	next() Return the next item in the queue.
int	size() Return the number of objects currently in the collection.
java.lang.String	toString() Return a string representation of this object.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

getLock_

private final java.lang.Object getLock_

addLock_

private final java.lang.Object addLock_

queue_

private final java.lang.Object[] queue_

capacity_

private final int capacity_

size_

private int size_

front_

private int front_

back_

private int back_

Constructor Detail

BlockingCircularQueue

public BlockingCircularQueue()

Create the queue with a capacity of 20

BlockingCircularQueue

public BlockingCircularQueue(int capacity)

Create the queue with the specified capacity

Parameters:

capacity - The size of the queue

Method Detail

clear

public void clear()

Remove all items from the queue

add

public boolean add(java.lang.Object object)

Add an object to the queue. If the collection is currently full then block until an object is removed.

Parameters:

object - The object to add.

Returns:

true if the object was successfully added.

next

public java.lang.Object next()

Return the next item in the queue. The returned item is removed from the collection. If no objects are present then block until an object has been added.

Returns:

The next item.

incrementPosition

private int incrementPosition(int position)

Utility method to increment the position and roll back to zero once we hit the end. Return the new position after the adjustment.

Parameters:

position - The position to increment

Returns:

the new position

size

public int size()

Return the number of objects currently in the collection.

Returns:

The object count.

isEmpty

public boolean isEmpty()

Return true if the collection is empty.

Returns:

true if the collection is empty.

toString

public java.lang.String toString()

Return a string representation of this object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this object.

assertNotNull

protected final void assertNotNull(java.lang.String fieldName,
                                   java.lang.Object fieldValue)
                            throws DetailedNullPointerException

Verify that the specified value is not null. If it is then throw an exception

Parameters:

fieldName - The name of the field to check

fieldValue - The value of the field to check

Throws:

DetailedNullPointerException - If fieldValue is null