org.d_haven.event.impl

Class DefaultPipe

java.lang.Object

org.d_haven.event.impl.AbstractPipe

org.d_haven.event.impl.DefaultPipe

All Implemented Interfaces:

Pipe, Sink, Source

public class DefaultPipe
extends AbstractPipe

The default queue implementation is a variable size queue. This queue is thread safe, however the overhead in synchronization costs a few extra milliseconds.

Author:

Berin Loritsch

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	DefaultPipe.DefaultPreparedEnqueue

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List	m_elements
protected int	m_reserve The number of reserve items.

Fields inherited from class org.d_haven.event.impl.AbstractPipe

m_interceptor, m_lock, m_predicate, m_timeout

Constructor Summary

Constructors

Constructor and Description
DefaultPipe() Create an unbounded DefaultPipe.
DefaultPipe(EnqueuePredicate predicate) Construct a new DefaultPipe with the supplied EnqueuePredicate.
DefaultPipe(int size) Construct a new DefaultPipe with the specified number of elements.

Method Summary

Methods

Modifier and Type	Method and Description
protected java.lang.Object	doDequeue() Abstract method to allow child classes to only focus on the part necessary to dequeue one event.
protected java.lang.Object[]	doDequeue(int numElements) Abstract method to allow child classes to only focus on the part necessary to dequeue the supplied number of events.
protected java.lang.Object[]	doDequeueAll() Abstract method to allow child classes to only focus on the part necessary to dequeue the remaining events.
protected void	doEnqueue(java.lang.Object element) Abstract method provided to allow the child classes to focus only on the portion of code needed to enqueue one event.
protected void	doEnqueue(java.lang.Object[] elements) Abstract method provided to allow the child classes to focus only on the portion of code needed to enqueue the supplied events.
protected PreparedEnqueue	doPrepareEnqueue(java.lang.Object[] elements) Abstract method provided to allow the child classes to focus only on the portion of code needed to do a prepared enqueue for the supplied events.
private static java.lang.Object[]	retrieveElements(java.util.List buf, int count) Removes the given number of elements from the given buf and returns them in an array.
int	size() Return the number of elements currently in the Pipe.
java.lang.String	toString() Get the string representation of this Pipe.

Methods inherited from class org.d_haven.event.impl.AbstractPipe

dequeue, dequeue, dequeueAll, enqueue, enqueue, getDequeueInterceptor, getEnqueuePredicate, prepareEnqueue, setDequeueInterceptor, setEnqueuePredicate, setTimeout, tryEnqueue

Methods inherited from class java.lang.Object

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

Field Detail

m_elements

private final java.util.List m_elements

m_reserve

protected int m_reserve

The number of reserve items. The reserve items are items that are held in a PreparedEnqueue object, but have not been committed yet.

Constructor Detail

DefaultPipe

public DefaultPipe()

Create an unbounded DefaultPipe.

DefaultPipe

public DefaultPipe(int size)

Construct a new DefaultPipe with the specified number of elements. if the number of elements is greater than zero, then the Pipe is bounded by that number. Otherwise, the Pipe is not bounded at all.

Parameters:

size - The maximum number of elements in the Pipe. Any number less than 1 means there is no limit.

DefaultPipe

public DefaultPipe(EnqueuePredicate predicate)

Construct a new DefaultPipe with the supplied EnqueuePredicate.

Parameters:

predicate - the EnqueuePredicate to use

Method Detail

size

public int size()

Return the number of elements currently in the Pipe.

Returns:

int representing the number of elements (including the reserved ones).

doPrepareEnqueue

protected PreparedEnqueue doPrepareEnqueue(java.lang.Object[] elements)

Description copied from class: AbstractPipe

Abstract method provided to allow the child classes to focus only on the portion of code needed to do a prepared enqueue for the supplied events.

Specified by:

doPrepareEnqueue in class AbstractPipe

Parameters:

elements - the events to enqueue

Returns:

the PreparedEnqueue object

doEnqueue

protected void doEnqueue(java.lang.Object[] elements)

Description copied from class: AbstractPipe

Abstract method provided to allow the child classes to focus only on the portion of code needed to enqueue the supplied events.

Specified by:

doEnqueue in class AbstractPipe

Parameters:

elements - the events to enqueue

doEnqueue

protected void doEnqueue(java.lang.Object element)

Description copied from class: AbstractPipe

Abstract method provided to allow the child classes to focus only on the portion of code needed to enqueue one event.

Specified by:

doEnqueue in class AbstractPipe

Parameters:

element - the event to enqueue

doDequeue

protected java.lang.Object[] doDequeue(int numElements)

Description copied from class: AbstractPipe

Abstract method to allow child classes to only focus on the part necessary to dequeue the supplied number of events.

Specified by:

doDequeue in class AbstractPipe

Parameters:

numElements - the number of elements to dequeue

Returns:

the next "num" events

doDequeueAll

protected java.lang.Object[] doDequeueAll()

Description copied from class: AbstractPipe

Abstract method to allow child classes to only focus on the part necessary to dequeue the remaining events.

Specified by:

doDequeueAll in class AbstractPipe

Returns:

the remaining events

retrieveElements

private static java.lang.Object[] retrieveElements(java.util.List buf,
                                  int count)

Removes the given number of elements from the given buf and returns them in an array. Trusts the caller to pass in a buffer full of Objects and with at least count elements available.

Parameters:

buf - to remove elements from, the caller is responsible for synchronizing access

count - number of elements to remove/return

Returns:

requested number of elements

doDequeue

protected java.lang.Object doDequeue()

Description copied from class: AbstractPipe

Abstract method to allow child classes to only focus on the part necessary to dequeue one event.

Specified by:

doDequeue in class AbstractPipe

Returns:

the next event

toString

public java.lang.String toString()

Get the string representation of this Pipe.

Overrides:

toString in class java.lang.Object

Returns:

the string message