org.apache.oozie.util

Class PriorityDelayQueue.QueueElement<E>

java.lang.Object

java.util.concurrent.FutureTask<E>

org.apache.oozie.util.PriorityDelayQueue.QueueElement<E>

All Implemented Interfaces:

Comparable<Delayed>, Runnable, Delayed, Future<E>, RunnableFuture<E>

Direct Known Subclasses:

CallableQueueService.CallableWrapper

Enclosing class:

PriorityDelayQueue<E>

public static class PriorityDelayQueue.QueueElement<E>
extends FutureTask<E>
implements Delayed

Element wrapper required by the queue.

This wrapper keeps track of the priority and the age of a queue element.

Constructor Summary

Constructors

Constructor and Description
QueueElement(XCallable<E> element, int priority, long delay, TimeUnit unit) Create an Element wrapper.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Delayed o) Compare the age of this wrapper element with another.
long	getDelay(TimeUnit unit) Return the delay of the element.
XCallable<E>	getElement() Return the element from the wrapper.
int	getPriority() Return the priority of the element.
void	setDelay(long delay, TimeUnit unit) Set the delay of the element.
String	toString() Return the string representation of the wrapper element.

Methods inherited from class java.util.concurrent.FutureTask

cancel, done, get, get, isCancelled, isDone, run, runAndReset, set, setException

Methods inherited from class java.lang.Object

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

Constructor Detail

QueueElement

public QueueElement(XCallable<E> element,
                    int priority,
                    long delay,
                    TimeUnit unit)

Create an Element wrapper.

Parameters:

element - element.

priority - priority of the element.

delay - delay of the element.

unit - time unit of the delay.

Throws:

IllegalArgumentException - if the element is NULL, the priority is negative or if the delay is negative.

Method Detail

getElement

public XCallable<E> getElement()

Return the element from the wrapper.

Returns:

the element.

getPriority

public int getPriority()

Return the priority of the element.

Returns:

the priority of the element.

setDelay

public void setDelay(long delay,
                     TimeUnit unit)

Set the delay of the element.

Parameters:

delay - delay of the element.

unit - time unit of the delay.

getDelay

public long getDelay(TimeUnit unit)

Return the delay of the element.

Specified by:

getDelay in interface Delayed

Parameters:

unit - time unit of the delay.

Returns:

the delay in the specified time unit.

compareTo

public int compareTo(Delayed o)

Compare the age of this wrapper element with another. The priority is not used for the comparision.

Specified by:

compareTo in interface Comparable<Delayed>

Parameters:

o - the other wrapper element to compare with.

Returns:

less than zero if this wrapper is older, zero if both wrapper elements have the same age, greater than zero if the parameter wrapper element is older.

toString

public String toString()

Return the string representation of the wrapper element.

Overrides:

toString in class Object

Returns:

the string representation of the wrapper element.