org.apache.curator.framework.recipes.queue

Class DistributedDelayQueue<T>

java.lang.Object

org.apache.curator.framework.recipes.queue.DistributedDelayQueue<T>

All Implemented Interfaces:

Closeable, AutoCloseable, QueueBase<T>

public class DistributedDelayQueue<T>
extends Object
implements Closeable, QueueBase<T>

A variation of the DistributedPriorityQueue that uses time as the priority. When items are added to the queue, a delay value is given. The item will not be sent to a consumer until the time elapses.

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	flushPuts(long waitTime, TimeUnit timeUnit) Wait until any pending puts are committed
int	getLastMessageCount() Return the most recent message count from the queue.
Listenable<QueuePutListener<T>>	getPutListenerContainer() Return the manager for put listeners
void	put(T item, long delayUntilEpoch) Add an item into the queue.
boolean	put(T item, long delayUntilEpoch, int maxWait, TimeUnit unit) Same as put(Object, long) but allows a maximum wait time if an upper bound was set via QueueBuilder.maxItems.
void	putMulti(MultiItem<T> items, long delayUntilEpoch) Add a set of items with the same priority into the queue.
boolean	putMulti(MultiItem<T> items, long delayUntilEpoch, int maxWait, TimeUnit unit) Same as putMulti(MultiItem, long) but allows a maximum wait time if an upper bound was set via QueueBuilder.maxItems.
void	setErrorMode(ErrorMode newErrorMode) Used when the queue is created with a QueueBuilder.lockPath(String).
void	start() Start the queue.

Methods inherited from class java.lang.Object

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

Method Detail

start

public void start()
           throws Exception

Start the queue. No other methods work until this is called

Specified by:

start in interface QueueBase<T>

Throws:

Exception - startup errors

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

put

public void put(T item,
                long delayUntilEpoch)
         throws Exception

Add an item into the queue. Adding is done in the background - thus, this method will return quickly.

NOTE: if an upper bound was set via QueueBuilder.maxItems, this method will block until there is available space in the queue.

Parameters:

item - item to add

delayUntilEpoch - future epoch (milliseconds) when this item will be available to consumers

Throws:

Exception - connection issues

put

public boolean put(T item,
                   long delayUntilEpoch,
                   int maxWait,
                   TimeUnit unit)
            throws Exception

Same as put(Object, long) but allows a maximum wait time if an upper bound was set via QueueBuilder.maxItems.

Parameters:

item - item to add

delayUntilEpoch - future epoch (milliseconds) when this item will be available to consumers

maxWait - maximum wait

unit - wait unit

Returns:

true if items was added, false if timed out

Throws:

Exception

putMulti

public void putMulti(MultiItem<T> items,
                     long delayUntilEpoch)
              throws Exception

Add a set of items with the same priority into the queue. Adding is done in the background - thus, this method will return quickly.

NOTE: if an upper bound was set via QueueBuilder.maxItems, this method will block until there is available space in the queue.

Parameters:

items - items to add

delayUntilEpoch - future epoch (milliseconds) when this item will be available to consumers

Throws:

Exception - connection issues

putMulti

public boolean putMulti(MultiItem<T> items,
                        long delayUntilEpoch,
                        int maxWait,
                        TimeUnit unit)
                 throws Exception

Same as putMulti(MultiItem, long) but allows a maximum wait time if an upper bound was set via QueueBuilder.maxItems.

Parameters:

items - items to add

delayUntilEpoch - future epoch (milliseconds) when this item will be available to consumers

maxWait - maximum wait

unit - wait unit

Returns:

true if items was added, false if timed out

Throws:

Exception

setErrorMode

public void setErrorMode(ErrorMode newErrorMode)

Description copied from interface: QueueBase

Used when the queue is created with a QueueBuilder.lockPath(String). Determines the behavior when the queue consumer throws an exception

Specified by:

setErrorMode in interface QueueBase<T>

Parameters:

newErrorMode - the new error mode (the default is ErrorMode.REQUEUE

flushPuts

public boolean flushPuts(long waitTime,
                         TimeUnit timeUnit)
                  throws InterruptedException

Description copied from interface: QueueBase

Wait until any pending puts are committed

Specified by:

flushPuts in interface QueueBase<T>

Parameters:

waitTime - max wait time

timeUnit - time unit

Returns:

true if the flush was successful, false if it timed out first

Throws:

InterruptedException - if thread was interrupted

getPutListenerContainer

public Listenable<QueuePutListener<T>> getPutListenerContainer()

Return the manager for put listeners

Specified by:

getPutListenerContainer in interface QueueBase<T>

Returns:

put listener container

getLastMessageCount

public int getLastMessageCount()

Return the most recent message count from the queue. This is useful for debugging/information purposes only.

Specified by:

getLastMessageCount in interface QueueBase<T>

Returns:

count (can be 0)