BackpressureStreamTransformer<S, T> class

A highly customizable StreamTransformer which can be configured to serve any of the common rx backpressure operators.

The StreamTransformer works by creating windows, during which it buffers events to a Queue.

The StreamTransformer works by creating windows, during which it buffers events to a Queue. It uses a WindowStrategy to determine how and when a new window is created.

onWindowStart and onWindowEnd are handlers that fire when a window opens and closes, right before emitting the transformed event.

startBufferEvery allows to skip events coming from the source Stream.

ignoreEmptyWindows can be set to true, to allow events to be emitted at the end of a window, even if the current buffer is empty. If the buffer is empty, then an empty List will be emitted. If false, then nothing is emitted on an empty buffer.

dispatchOnClose will cause the remaining values in the buffer to be emitted when the source Stream closes. When false, the remaining buffer is discarded on close.

Inheritance
Implementers

Constructors

BackpressureStreamTransformer(WindowStrategy strategy, Stream windowStreamFactory(S event)?, {T onWindowStart(S event)?, T onWindowEnd(List<S> queue)?, int startBufferEvery = 0, bool closeWindowWhen(List<S> queue)?, bool ignoreEmptyWindows = true, bool dispatchOnClose = true, int? maxLengthQueue})
Constructs a StreamTransformer which buffers events emitted by the Stream that is created by windowStreamFactory.

Properties

closeWindowWhen → bool Function(List<S> queue)?
Predicate which determines when the current window should close
final
dispatchOnClose → bool
Toggle to prevent, or allow the final set of events to be dispatched when the source Stream closes
final
hashCode → int
The hash code for this object.
no setterinherited
ignoreEmptyWindows → bool
Toggle to prevent, or allow windows that contain no events to be dispatched
final
maxLengthQueue → int?
Maximum length of the buffer. Specify this value to avoid running out of memory when adding too many events to the buffer. If it's null, maximum length of the buffer is unlimited.
final
onWindowEnd → T Function(List<S> queue)?
Handler which fires when the window closes
final
onWindowStart → T Function(S event)?
Handler which fires when the window opens
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
startBufferEvery → int
Used to skip an amount of events
final
strategy → WindowStrategy
Determines how the window is created
final
windowStreamFactory → Stream Function(S event)?
Factory method used to create the Stream which will be buffered
final

Methods

bind(Stream<S> stream) → Stream<T>
Transforms the provided stream.
override
cast<RS, RT>() → StreamTransformer<RS, RT>
Provides a StreamTransformer<RS, RT> view of this stream transformer.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited