org.transitime.avl

Class AvlQueue

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

org.transitime.avl.AvlQueue

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<java.lang.Runnable>, java.util.Collection<java.lang.Runnable>, java.util.concurrent.BlockingQueue<java.lang.Runnable>, java.util.Queue<java.lang.Runnable>

public class AvlQueue
extends java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

A queue of AvlClient runnables that can be used with a ThreadPoolExecutor. Implements by subclassing a ArrayBlockingQueue where the Runnable is an AvlClient. Also keeps track of the last AVL report per vehicle. When getting data form queue, if the data is obsolete (a new AVL report has been received for the vehicle) then that element from the queue is thrown out and the next item is retrieved until a non-obsolete one is found.

Extended ArrayBlockingQueue class so that don't have to create a blocking queue from scratch.

Note: wanted to extend from ArrayBlockingQueue but that didn't work for the ThreadPoolExecutor which expects a BlockingQueue. So had to resort to doing ugly casts.

Author:

SkiBu Smith

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AvlQueue(int queueSize) Constructs the queue to have specified size.

Method Summary

Modifier and Type	Method and Description
boolean	add(java.lang.Runnable runnable) Calls superclass add() method but also updates the AVL data per vehicle map.
boolean	offer(java.lang.Runnable runnable) Calls superclass offer() method but also updates the AVL data per vehicle map.
boolean	offer(java.lang.Runnable runnable, long timeout, java.util.concurrent.TimeUnit unit) Calls superclass offer(timeout, unit) method but also updates the AVL data per vehicle map.
java.lang.Runnable	poll() Calls superclass poll() method until it gets AVL data that is not obsolete.
java.lang.Runnable	poll(long timeout, java.util.concurrent.TimeUnit unit) Calls superclass poll(timeout, unit) method until it gets AVL data that is not obsolete.
void	put(java.lang.Runnable runnable) Calls superclass add() method but also updates the AVL data per vehicle map.
java.lang.Runnable	take() Calls superclass take() method until it gets AVL data that is not obsolete.

Methods inherited from class java.util.concurrent.ArrayBlockingQueue

clear, contains, drainTo, drainTo, iterator, peek, remainingCapacity, remove, size, spliterator, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

addAll, element, remove

Methods inherited from class java.util.AbstractCollection

containsAll, isEmpty, removeAll, retainAll

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Queue

element, remove

Methods inherited from interface java.util.Collection

addAll, containsAll, equals, hashCode, isEmpty, parallelStream, removeAll, removeIf, retainAll, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

AvlQueue

public AvlQueue(int queueSize)

Constructs the queue to have specified size.

Parameters:

queueSize - How many AVL elements can be put into the queue before it blocks.

Method Detail

add

public boolean add(java.lang.Runnable runnable)

Calls superclass add() method but also updates the AVL data per vehicle map. Doesn't seem to be used by ThreadPoolExecutor but still included for completeness.

Specified by:

add in interface java.util.Collection<java.lang.Runnable>

Specified by:

add in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Specified by:

add in interface java.util.Queue<java.lang.Runnable>

Overrides:

add in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

put

public void put(java.lang.Runnable runnable)
         throws java.lang.InterruptedException

Calls superclass add() method but also updates the AVL data per vehicle map. Doesn't seem to be used by ThreadPoolExecutor but still included for completeness.

Specified by:

put in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Overrides:

put in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

Throws:

java.lang.InterruptedException

offer

public boolean offer(java.lang.Runnable runnable)

Calls superclass offer() method but also updates the AVL data per vehicle map. Used by ThreadPoolExecutor.

Specified by:

offer in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Specified by:

offer in interface java.util.Queue<java.lang.Runnable>

Overrides:

offer in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

offer

public boolean offer(java.lang.Runnable runnable,
                     long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException

Calls superclass offer(timeout, unit) method but also updates the AVL data per vehicle map. Doesn't seem to be used by ThreadPoolExecutor but still included for completeness.

Specified by:

offer in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Overrides:

offer in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

Throws:

java.lang.InterruptedException

poll

public java.lang.Runnable poll()

Calls superclass poll() method until it gets AVL data that is not obsolete. Doesn't seem to be used by ThreadPoolExecutor but still included for completeness.

Specified by:

poll in interface java.util.Queue<java.lang.Runnable>

Overrides:

poll in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

poll

public java.lang.Runnable poll(long timeout,
                               java.util.concurrent.TimeUnit unit)
                        throws java.lang.InterruptedException

Calls superclass poll(timeout, unit) method until it gets AVL data that is not obsolete. Used by ThreadPoolExecutor.

Specified by:

poll in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Overrides:

poll in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

Throws:

java.lang.InterruptedException

take

public java.lang.Runnable take()
                        throws java.lang.InterruptedException

Calls superclass take() method until it gets AVL data that is not obsolete. Doesn't seem to be used by ThreadPoolExecutor but still included for completeness.

Specified by:

take in interface java.util.concurrent.BlockingQueue<java.lang.Runnable>

Overrides:

take in class java.util.concurrent.ArrayBlockingQueue<java.lang.Runnable>

Throws:

java.lang.InterruptedException