Package com.github.ddth.queue.impl

Class InmemQueue<ID,DATA>

java.lang.Object

com.github.ddth.queue.impl.AbstractQueue<ID,DATA>

com.github.ddth.queue.impl.AbstractEphemeralSupportQueue<ID,DATA>

com.github.ddth.queue.impl.AbstractInmemEphemeralQueue<ID,DATA>

com.github.ddth.queue.impl.InmemQueue<ID,DATA>

All Implemented Interfaces:

IQueue<ID,DATA>, AutoCloseable

Direct Known Subclasses:

BaseUniversalInmemQueue

public class InmemQueue<ID,DATA>
extends AbstractInmemEphemeralQueue<ID,DATA>

In-Memory implementation of IQueue.

Implementation:

• A Queue as queue storage.
• A ConcurrentMap as ephemeral storage.

Features:

• Queue-size support: yes
• Ephemeral storage support: yes
• Ephemeral-size support: yes

Since:

0.4.0

Author:

Thanh Ba Nguyen

Nested Class Summary

Nested classes/interfaces inherited from class com.github.ddth.queue.impl.AbstractQueue

AbstractQueue.PutToQueueCase

Field Summary

Fields inherited from interface com.github.ddth.queue.IQueue

SIZE_NOT_SUPPORTED

Constructor Summary

Constructors

Constructor	Description
InmemQueue()
InmemQueue(int boundary)

Method Summary

Modifier and Type	Method	Description
protected Queue<IQueueMessage<ID,DATA>>	createQueue(int boundary)	This method will create a Queue instance with the following rules: If boundary is set and larger than 1024, a LinkedBlockingQueue is created; if boundary is less than or equals to 1024, an ArrayBlockingQueue is created instead. Otherwise, a ConcurrentLinkedQueue is created.
protected boolean	doPutToQueue(IQueueMessage<ID,DATA> msg, AbstractQueue.PutToQueueCase queueCase)	Put a message to the queue storage.
void	finish(IQueueMessage<ID,DATA> msg)	Called when finish processing the message to cleanup ephemeral storage.
int	getBoundary()	Gets queue's boundary (max number of elements).
InmemQueue<ID,DATA>	init()	Init method.
int	queueSize()	Get number of items currently in queue storage.
InmemQueue<ID,DATA>	setBoundary(int boundary)	Sets queue's boundary (max number of elements).
IQueueMessage<ID,DATA>	take()	Take a message out of queue.
protected IQueueMessage<ID,DATA>	takeFromQueue()	Takes a message from the internal queue.

Methods inherited from class com.github.ddth.queue.impl.AbstractInmemEphemeralQueue

doPutToEphemeralStorage, doRemoveFromEphemeralStorage, ensureEphemeralSize, ephemeralSize, getOrphanMessages, initEphemeralStorage, setEphemeralDisabled

Methods inherited from class com.github.ddth.queue.impl.AbstractEphemeralSupportQueue

getEphemeralDisabled, getEphemeralMaxSize, isEphemeralDisabled, setEphemeralMaxSize

Methods inherited from class com.github.ddth.queue.impl.AbstractQueue

close, createMessage, createMessage, createMessage, deserialize, deserialize, destroy, getMessageFactory, getQueueName, getSerDeser, queue, requeue, requeueSilent, serialize, setMessageFactory, setQueueName, setSerDeser

Methods inherited from class java.lang.Object

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

Constructor Detail

InmemQueue

public InmemQueue()

InmemQueue

public InmemQueue(int boundary)

Method Detail

getBoundary

public int getBoundary()

Gets queue's boundary (max number of elements).

Returns:

setBoundary

public InmemQueue<ID,DATA> setBoundary(int boundary)

Sets queue's boundary (max number of elements).

Parameters:

boundary - queue's max number of elements, a value less than 1 mean "no boundary".

Returns:

createQueue

protected Queue<IQueueMessage<ID,DATA>> createQueue(int boundary)

This method will create a Queue instance with the following rules:

• If boundary is set and larger than 1024, a LinkedBlockingQueue is created; if boundary is less than or equals to 1024, an ArrayBlockingQueue is created instead.
• Otherwise, a ConcurrentLinkedQueue is created.

Parameters:

boundary -

Returns:

init

public InmemQueue<ID,DATA> init()
                               throws Exception

Init method.

Overrides:

init in class AbstractQueue<ID,DATA>

Returns:

Throws:

Exception

doPutToQueue

protected boolean doPutToQueue(IQueueMessage<ID,DATA> msg,
                               AbstractQueue.PutToQueueCase queueCase)
                        throws QueueException.QueueIsFull

Put a message to the queue storage.

Sub-class implements this method.

Specified by:

doPutToQueue in class AbstractQueue<ID,DATA>

Returns:

Throws:

QueueException.QueueIsFull

finish

public void finish(IQueueMessage<ID,DATA> msg)

Called when finish processing the message to cleanup ephemeral storage.

Implementation flow:

• Remove message from ephemeral storage.

Note: ephemeral storage implementation is optional, depends on implementation.

takeFromQueue

protected IQueueMessage<ID,DATA> takeFromQueue()

Takes a message from the internal queue.

Returns:

take

public IQueueMessage<ID,DATA> take()
                                  throws QueueException.EphemeralIsFull

Take a message out of queue.

Implementation flow:

• Read message from head of queue storage.
• Write message to ephemeral storage.
• Remove message from queue storage.

Note: ephemeral storage implementation is optional, depends on implementation.

Returns:

Throws:

QueueException.EphemeralIsFull - if the ephemeral storage is full

queueSize

public int queueSize()

Get number of items currently in queue storage.

Returns:

negative number if queue size can not be queried