Package com.scaleoutsoftware.collections.timewindowing

Class WatermarkedSlidingWindowCollection<T>

java.lang.Object

com.scaleoutsoftware.collections.timewindowing.WatermarkedWindowingCollection<T>

com.scaleoutsoftware.collections.timewindowing.WatermarkedSlidingWindowCollection<T>

Type Parameters:

T - the object type of the source collection.

All Implemented Interfaces:

Iterable<TimeWindow<T>>

public class WatermarkedSlidingWindowCollection<T>
extends WatermarkedWindowingCollection<T>

The SlidingWindowCollection transforms a collection into an iterable collection of overlapping time windows. This wrapper class can be used to manage the retention policy and add objects in chronological order to the underlying source collection. The difference between SlidingWindowCollection and WatermarkedSlidingWindowCollection is that windows in the WatermarkedSlidingWindowCollection can be closed if the watermark passes the inclusive end of a window. The watermark also prevents items with timestamps that exceed the watermark from being added to the collection.

Field Summary

Fields inherited from class com.scaleoutsoftware.collections.timewindowing.WatermarkedWindowingCollection

sourceCollection, startTimeMs, timestampSelector, watermarkGenerator, watermarkMs

Constructor Summary

Constructors

Constructor	Description
WatermarkedSlidingWindowCollection(List<T> sourceCollection, TimestampSelector<T> timestampSelector, long startTimeMs, long windowDurationMs, long everyMs, WatermarkGenerator watermarkGenerator)	Instantiates a new WatermarkedSlidingWindowCollection.
WatermarkedSlidingWindowCollection(List<T> sourceCollection, TimestampSelector<T> timestampSelector, long nextWindowStartTimeMs, long windowDurationMs, long everyMs, WatermarkGenerator watermarkGenerator, long currentWatermarkMs)	Instantiates a new WatermarkedSlidingWindowCollection.

Method Summary

Modifier and Type	Method	Description
void	forEach(Consumer<? super TimeWindow<T>> action)
long	getEveryMs()	Retrieves the window created "every" in milliseconds.
long	getNextWindowStartTimeMs()	Retrieves the next window start time in milliseconds.
long	getWindowDurationMs()	Retrieves the configured window duration in milliseconds.
Iterator<TimeWindow<T>>	iterator()
Spliterator<TimeWindow<T>>	spliterator()

Methods inherited from class com.scaleoutsoftware.collections.timewindowing.WatermarkedWindowingCollection

add, getSourceCollection, getStartTimeMs, getTimestampSelector, getWatermarkGenerator, getWatermarkMs

Methods inherited from class java.lang.Object

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

Constructor Details

WatermarkedSlidingWindowCollection

public WatermarkedSlidingWindowCollection(List<T> sourceCollection,
 TimestampSelector<T> timestampSelector,
 long startTimeMs,
 long windowDurationMs,
 long everyMs,
 WatermarkGenerator watermarkGenerator)

Instantiates a new WatermarkedSlidingWindowCollection.

Parameters:

sourceCollection - the underlying source collection

timestampSelector - the TimestampSelector is used to pull a timestamp from an item in the source collection and subsequent insertions.

startTimeMs - the first time an object can be in a time window -- items before the start time will be evicted. The start time is also the start time of the first time window.

windowDurationMs - the duration of a time window

everyMs - the time between the starting point of each time window

watermarkGenerator - the WatermarkGenerator is used to generate a watermark. Entries that arrive before the watermark time are evicted. Windows whose inclusive end exceeds the watermark are closed.

WatermarkedSlidingWindowCollection

public WatermarkedSlidingWindowCollection(List<T> sourceCollection,
 TimestampSelector<T> timestampSelector,
 long nextWindowStartTimeMs,
 long windowDurationMs,
 long everyMs,
 WatermarkGenerator watermarkGenerator,
 long currentWatermarkMs)

Instantiates a new WatermarkedSlidingWindowCollection.

Parameters:

sourceCollection - the underlying source collection

timestampSelector - the TimestampSelector is used to pull a timestamp from an item in the source collection and subsequent insertions.

nextWindowStartTimeMs - the first time an object can be in a time window -- items before the start time will be evicted. The start time is also the start time of the first time window.

windowDurationMs - the duration of a time window

everyMs - the time between the starting point of each time window

watermarkGenerator - the WatermarkGenerator is used to generate a watermark. Entries that arrive before the watermark time are evicted. Windows whose inclusive end exceeds the watermark are closed.

currentWatermarkMs - the current watermark in milliseconds.

Method Details

getWindowDurationMs

public long getWindowDurationMs()

Retrieves the configured window duration in milliseconds.

Returns:

the window duration in milliseconds.

getEveryMs

public long getEveryMs()

Retrieves the window created "every" in milliseconds.

Returns:

the window every in milliseconds.

getNextWindowStartTimeMs

public long getNextWindowStartTimeMs()

Retrieves the next window start time in milliseconds.

Returns:

the next window start time in milliseconds.

iterator

public Iterator<TimeWindow<T>> iterator()

forEach

public void forEach(Consumer<? super TimeWindow<T>> action)

spliterator

public Spliterator<TimeWindow<T>> spliterator()