Class WatermarkedTumblingWindowCollection<T>

Namespace

Scaleout.Streaming.TimeWindowing

Assembly

Scaleout.Streaming.TimeWindowing.dll

A collection of tumbling time windows that are generated from a source collection of elements. Each window has a fixed duration and does not overlap with other windows.

public class WatermarkedTumblingWindowCollection<T> : IEnumerable<ITimeWindow<T>>, IEnumerable

Type Parameters

T

The type of elements in the collection.

Inheritance

object

WatermarkedTumblingWindowCollection<T>

Implements

IEnumerable<ITimeWindow<T>>

IEnumerable

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Extension Methods

SessionWindowExtensions.ToSessionWindows<TSource>(IEnumerable<TSource>, Func<TSource, DateTime>, TimeSpan)

SlidingWindowExtensions.ToSlidingWindows<TSource>(IEnumerable<TSource>, Func<TSource, DateTime>, DateTime, DateTime, TimeSpan, TimeSpan)

TumblingWindowExtensions.ToTumblingWindows<TSource>(IEnumerable<TSource>, Func<TSource, DateTime>, DateTime, DateTime, TimeSpan)

Remarks

The underlying collection is expected to be ordered by timestamp, and the time windows are generated based on a tumbling window algorithm. The collection also supports watermark-based closure of time windows and eviction of old elements from the underlying collection.

Constructors

WatermarkedTumblingWindowCollection(ICollection<T>, Func<T, DateTime>, TimeSpan, DateTime, Func<DateTime, DateTime>)

Constructor.

public WatermarkedTumblingWindowCollection(ICollection<T> source, Func<T, DateTime> timestampSelector, TimeSpan windowDuration, DateTime startTime, Func<DateTime, DateTime> watermarkGenerator)

Parameters

source ICollection<T>

The source collection of elements.

timestampSelector Func<T, DateTime>

A function to extract the timestamp from each element.

windowDuration TimeSpan

The duration of each tumbling window.

startTime DateTime

The start time for the first window.

watermarkGenerator Func<DateTime, DateTime>

A function to generate the watermark based on the time of the latest element added. Entries that arrive before the watermark time are evicted.

WatermarkedTumblingWindowCollection(ICollection<T>, Func<T, DateTime>, TimeSpan, DateTime, Func<DateTime, DateTime>, DateTime)

Constructor.

public WatermarkedTumblingWindowCollection(ICollection<T> source, Func<T, DateTime> timestampSelector, TimeSpan windowDuration, DateTime startTime, Func<DateTime, DateTime> watermarkGenerator, DateTime currentWatermark)

Parameters

source ICollection<T>

The source collection of elements.

timestampSelector Func<T, DateTime>

A function to extract the timestamp from each element.

windowDuration TimeSpan

The duration of each tumbling window.

startTime DateTime

The start time for the first window.

watermarkGenerator Func<DateTime, DateTime>

A function to generate the watermark based on the time of the latest element added. Entries that arrive before the watermark time are evicted.

currentWatermark DateTime

The current watermark time.

Properties

CurrentWatermark

public DateTime CurrentWatermark { get; }

Property Value

DateTime

Items

public IReadOnlyCollection<T> Items { get; }

Property Value

IReadOnlyCollection<T>

StartTime

public DateTime StartTime { get; }

Property Value

DateTime

WindowDuration

public TimeSpan WindowDuration { get; }

Property Value

TimeSpan

Methods

Add(T)

Adds an element to the underlying collection, inserting it into the underlying source collection in chronological order. If the timestamp associated with the new element falls before the collection's current watermark provided to this transformation's constructor then the new element will be evicted immediately.

public IEnumerable<ITimeWindow<T>> Add(T item)

Parameters

item T

The element to add to the collection.

Returns

IEnumerable<ITimeWindow<T>>

GetEnumerator()

Returns an enumerator that iterates through the collection of time windows.

public IEnumerator<ITimeWindow<T>> GetEnumerator()

Returns

IEnumerator<ITimeWindow<T>>

An enumerator that can be used to iterate through the collection of ITimeWindow<TElement> elements.