Package org.apache.qpid.protonj2.client.util

Class FifoDeliveryQueue

java.lang.Object

org.apache.qpid.protonj2.client.util.FifoDeliveryQueue

All Implemented Interfaces:

DeliveryQueue

public final class FifoDeliveryQueue
extends Object
implements DeliveryQueue

Simple first in / first out Delivery Queue.

Constructor Summary

Constructors

Constructor	Description
FifoDeliveryQueue(int queueDepth)	Creates a new first in / first out message queue with the given queue depth

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the Queue of any queued Delivery values.
void	close()	Closes the Delivery Queue.
ClientDelivery	dequeue(long timeout)	Used to get an Delivery.
ClientDelivery	dequeueNoWait()	Used to get an enqueued Delivery if on exists, otherwise returns null.
void	enqueue(ClientDelivery envelope)	Adds the given Delivery to the end of the Delivery queue.
void	enqueueFirst(ClientDelivery envelope)	Adds the given Delivery to the front of the queue.
boolean	isClosed()
boolean	isEmpty()
boolean	isRunning()
int	size()	Returns the number of deliveries currently in the Queue.
void	start()	Starts the Delivery Queue.
void	stop()	Stops the Delivery Queue.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

FifoDeliveryQueue

public FifoDeliveryQueue(int queueDepth)

Creates a new first in / first out message queue with the given queue depth

Parameters:

queueDepth - The Queue depth to configure for this FIFO Message Queue.

Method Detail

enqueueFirst

public void enqueueFirst(ClientDelivery envelope)

Description copied from interface: DeliveryQueue

Adds the given Delivery to the front of the queue.

Specified by:

enqueueFirst in interface DeliveryQueue

Parameters:

envelope - The in-bound Delivery to enqueue.

enqueue

public void enqueue(ClientDelivery envelope)

Description copied from interface: DeliveryQueue

Adds the given Delivery to the end of the Delivery queue.

Specified by:

enqueue in interface DeliveryQueue

Parameters:

envelope - The in-bound Delivery to enqueue.

dequeue

public ClientDelivery dequeue(long timeout)
                       throws InterruptedException

Description copied from interface: DeliveryQueue

Used to get an Delivery. The amount of time this method blocks is based on the timeout value that is supplied to it.

• If the timeout value is less than zero the dequeue operation blocks until a Delivery is enqueued or the queue is stopped.
• If the timeout value is zero the dequeue operation will not block and will either return the next Delivery on the Queue or null to indicate the queue is empty.
• If the timeout value is greater than zero then the method will either return the next Delivery in the queue or block until the timeout (in milliseconds) has expired or until a new Delivery is placed onto the queue.

Specified by:

dequeue in interface DeliveryQueue

Parameters:

timeout - The amount of time to wait for an entry to be added before returning null.

Returns:

null if we timeout or if the Receiver is closed.

Throws:

InterruptedException - if the wait is interrupted.

dequeueNoWait

public ClientDelivery dequeueNoWait()

Description copied from interface: DeliveryQueue

Used to get an enqueued Delivery if on exists, otherwise returns null.

Specified by:

dequeueNoWait in interface DeliveryQueue

Returns:

the next Delivery in the Queue if one exists, otherwise null.

start

public void start()

Description copied from interface: DeliveryQueue

Starts the Delivery Queue. An non-started Queue will always return null for any of the Queue methods.

Specified by:

start in interface DeliveryQueue

stop

public void stop()

Description copied from interface: DeliveryQueue

Stops the Delivery Queue. Deliveries cannot be read from the Queue when it is in the stopped state and any waiters will be woken.

Specified by:

stop in interface DeliveryQueue

close

public void close()

Description copied from interface: DeliveryQueue

Closes the Delivery Queue. No Delivery can be added or removed from the Queue once it has entered the closed state.

Specified by:

close in interface DeliveryQueue

isRunning

public boolean isRunning()

Specified by:

isRunning in interface DeliveryQueue

Returns:

true if the Queue is not in the stopped or closed state.

isClosed

public boolean isClosed()

Specified by:

isClosed in interface DeliveryQueue

Returns:

true if the Queue has been closed.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface DeliveryQueue

Returns:

true if there are no deliveries in the queue.

size

public int size()

Description copied from interface: DeliveryQueue

Returns the number of deliveries currently in the Queue. This value is only meaningful at the time of the call as the size of the Queue changes rapidly as deliveries arrive and are consumed.

Specified by:

size in interface DeliveryQueue

Returns:

the current number of Delivery objects in the Queue.

clear

public void clear()

Description copied from interface: DeliveryQueue

Clears the Queue of any queued Delivery values.

Specified by:

clear in interface DeliveryQueue

toString

public String toString()

Overrides:

toString in class Object