Package org.apache.synapse.commons.executors

Class MultiPriorityBlockingQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

org.apache.synapse.commons.executors.MultiPriorityBlockingQueue<E>

Type Parameters:

E - E should implement the Importance interface.

All Implemented Interfaces:

Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>

public class MultiPriorityBlockingQueue<E>
extends AbstractQueue<E>
implements BlockingQueue<E>

This queue implements the BlockingQueue interface. The element should implement the Importance interface.

Internally Queue is implemented as a set of multiple queues corresponding to some fixed priorities. When inserting an element, it will be put in to one of these queues depending on its importance.

Constructor Summary

Constructors

Constructor	Description
MultiPriorityBlockingQueue(List<InternalQueue<E>> queues, boolean isFixedQueues, NextQueueAlgorithm<E> algorithm)	Create a queue with the given queues.

Method Summary

Modifier and Type	Method	Description
void	clear()
boolean	contains(Object o)
int	drainTo(Collection<? super E> c)	We always give high priority to highest priority elements.
int	drainTo(Collection<? super E> c, int maxElements)	We always give high priority to highest priotiry elements.
NextQueueAlgorithm<E>	getNextQueueAlgorithm()
List<InternalQueue<E>>	getQueues()
boolean	isEmpty()
boolean	isFixedSizeQueues()
Iterator<E>	iterator()
boolean	offer(E e)	Add the element if space available in the internal queue corresponding to the priority of the object.
boolean	offer(E e, long timeout, TimeUnit unit)	Try to add the element within the given time period.
E	peek()
E	poll()	Block indefinitely until a object is available for retrieval.
E	poll(long timeout, TimeUnit unit)	Get the element from the top of the queue.
void	put(E e)	Put the specified value in to the queue.
int	remainingCapacity()
boolean	remove(Object o)
int	size()
E	take()	Get an element.
Object[]	toArray()
<T> T[]	toArray(T[] a)
String	toString()

Methods inherited from class java.util.AbstractQueue

add, addAll, element, remove

Methods inherited from class java.util.AbstractCollection

containsAll, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.concurrent.BlockingQueue

add

Methods inherited from interface java.util.Collection

addAll, containsAll, equals, hashCode, parallelStream, removeAll, removeIf, retainAll, spliterator, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Queue

element, remove

Constructor Detail

MultiPriorityBlockingQueue

public MultiPriorityBlockingQueue(List<InternalQueue<E>> queues,
                                  boolean isFixedQueues,
                                  NextQueueAlgorithm<E> algorithm)

Create a queue with the given queues.

This method will create a Queue that accepts objects with only the priorities specified. If a object is submitted with a different priority it will result in an IllegalArgumentException. If the algorithm is null, this queue will use the PRRNextQueueAlgorithm.

Parameters:

queues - list of InternalQueue to be used

isFixedQueues - weather fixed size queues are used

algorithm - algorithm for calculating next queue

Method Detail

put

public void put(E e)
         throws InterruptedException

Put the specified value in to the queue. The put will block until space available in the corresponding internal queue.

Specified by:

put in interface BlockingQueue<E>

Parameters:

e - object that implements the Importance interface

Throws:

InterruptedException

offer

public boolean offer(E e)

Add the element if space available in the internal queue corresponding to the priority of the object.

Specified by:

offer in interface BlockingQueue<E>

Specified by:

offer in interface Queue<E>

Parameters:

e - element to be added

Returns:

true if element is added

offer

public boolean offer(E e,
                     long timeout,
                     TimeUnit unit)
              throws InterruptedException

Try to add the element within the given time period. Wait the specified time for space to be available. This method will put the object in to the internal queue with the corresponding priority. This method blocks only if that internal queue is full.

Specified by:

offer in interface BlockingQueue<E>

Parameters:

e - element to be added

timeout - time to wait if space not available

unit - time unit

Returns:

true if the element is added

Throws:

InterruptedException - if the thread is interrupted

take

public E take()
       throws InterruptedException

Get an element. Block until an element is available

Specified by:

take in interface BlockingQueue<E>

Returns:

an element

Throws:

InterruptedException - if the thread is interrupted

poll

public E poll(long timeout,
              TimeUnit unit)
       throws InterruptedException

Get the element from the top of the queue. If an element is not available wait the specified timeout.

Specified by:

poll in interface BlockingQueue<E>

Parameters:

timeout - waiting time for element to be available

unit - time unit

Returns:

an object

Throws:

InterruptedException

drainTo

public int drainTo(Collection<? super E> c)

We always give high priority to highest priority elements. We try to drain all the high priority items first.

Specified by:

drainTo in interface BlockingQueue<E>

Parameters:

c - collection to drain the items

Returns:

number of elements copied

drainTo

public int drainTo(Collection<? super E> c,
                   int maxElements)

We always give high priority to highest priotiry elements. We try to drain all the high priority items first.

Specified by:

drainTo in interface BlockingQueue<E>

Parameters:

c - collection to drain the itemd

maxElements - maximum elements to copy

Returns:

number of elements copied

poll

public E poll()

Block indefinitely until a object is available for retrieval.

Specified by:

poll in interface Queue<E>

Returns:

an object

remainingCapacity

public int remainingCapacity()

Specified by:

remainingCapacity in interface BlockingQueue<E>

peek

public E peek()

Specified by:

peek in interface Queue<E>

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in class AbstractCollection<E>

size

public int size()

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

Overrides:

isEmpty in class AbstractCollection<E>

remove

public boolean remove(Object o)

Specified by:

remove in interface BlockingQueue<E>

Specified by:

remove in interface Collection<E>

Overrides:

remove in class AbstractCollection<E>

contains

public boolean contains(Object o)

Specified by:

contains in interface BlockingQueue<E>

Specified by:

contains in interface Collection<E>

Overrides:

contains in class AbstractCollection<E>

toString

public String toString()

Overrides:

toString in class AbstractCollection<E>

clear

public void clear()

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractQueue<E>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface Collection<E>

Overrides:

toArray in class AbstractCollection<E>

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<E>

Overrides:

toArray in class AbstractCollection<E>

getQueues

public List<InternalQueue<E>> getQueues()

getNextQueueAlgorithm

public NextQueueAlgorithm<E> getNextQueueAlgorithm()

isFixedSizeQueues

public boolean isFixedSizeQueues()