org.diirt.datasource

Class QueueCollector<T>

java.lang.Object

org.diirt.datasource.QueueCollector<T>

Type Parameters:

T - the type contained in the queue

All Implemented Interfaces:

Collector<T,List<T>>, ReadFunction<List<T>>, WriteFunction<T>

public class QueueCollector<T>
extends Object
implements Collector<T,List<T>>

Collects value at read rate and puts them in a queue.

Always returns new value as every read clears the cache. The values are returned oldest value first. When maxSize is reached, the oldest values are discarded.

Author:

carcassi

Constructor Summary

Constructors

Constructor and Description
QueueCollector(int maxSize) New queue collector with the given max size for the queue.

Method Summary

Modifier and Type	Method and Description
int	getMaxSize() The maximum number of elements in the queue.
List<T>	readValue() Calculates, if needed, and then returns the value for this function.
void	setChangeNotification(Runnable notification) Task to run to notify of the presence of a new value in the collector.
void	setMaxSize(int maxSize) Changes the number of maximum values in the queue.
void	writeValue(T newValue) Takes the value and consumes it.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueueCollector

public QueueCollector(int maxSize)

New queue collector with the given max size for the queue.

Parameters:

maxSize - maximum number of elements in the queue

Method Detail

setChangeNotification

public void setChangeNotification(Runnable notification)

Description copied from interface: Collector

Task to run to notify of the presence of a new value in the collector.

Specified by:

setChangeNotification in interface Collector<T,List<T>>

Parameters:

notification - callback for the notification

writeValue

public void writeValue(T newValue)

Description copied from interface: WriteFunction

Takes the value and consumes it.

Specified by:

writeValue in interface WriteFunction<T>

Parameters:

newValue - a value

readValue

public List<T> readValue()

Description copied from interface: ReadFunction

Calculates, if needed, and then returns the value for this function.

Specified by:

readValue in interface ReadFunction<List<T>>

Returns:

a value

setMaxSize

public void setMaxSize(int maxSize)

Changes the number of maximum values in the queue.

If new maxSize is less than the current number of element in the queue, the old values are discarded.

Parameters:

maxSize - the maximum number of elements in the queue

getMaxSize

public int getMaxSize()

The maximum number of elements in the queue.

Returns:

the maximum number of elements in the queue