abstract class Topic[F[_], A] extends AnyRef
Topic allows you to distribute A
s published by an arbitrary
number of publishers to an arbitrary number of subscribers.
Topic has built-in back-pressure support implemented as the maximum
number of elements (maxQueued
) that a subscriber is allowed to enqueue.
Once that bound is hit, any publishing action will semantically block until the lagging subscriber consumes some of its queued elements.
- Self Type
- Topic[F, A]
- Source
- Topic.scala
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- Topic
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Instance Constructors
- new Topic()
Abstract Value Members
-
abstract
def
publish: Pipe[F, A, Nothing]
Publishes elements from source of
A
to this topic.Publishes elements from source of
A
to this topic. Pipe equivalent ofpublish1
. -
abstract
def
publish1(a: A): F[Unit]
Publishes one
A
to topic.Publishes one
A
to topic.This operation does not complete until after the given element has been enqued on all subscribers, which means that if any subscriber is at its
maxQueued
limit,publish1
will semantically block until that subscriber consumes an element.A semantically blocked publication can be interrupted, but there is no guarantee of atomicity, and it could result in the
A
being received by some subscribers only.Note: if
publish1
is called concurrently by multiple producers, different subscribers may receive messages from different producers in a different order. -
abstract
def
subscribe(maxQueued: Int): Stream[F, A]
Subscribes for
A
values that are published to this topic.Subscribes for
A
values that are published to this topic.Pulling on the returned stream opens a "subscription", which allows up to
maxQueued
elements to be enqueued as a result of publication.If at any point, the queue backing the subscription has
maxQueued
elements in it, any further publications semantically block until elements are dequeued from the subscription queue.- maxQueued
maximum number of elements to enqueue to the subscription queue before blocking publishers
-
abstract
def
subscribeAwait(maxQueued: Int): Resource[F, Stream[F, A]]
Like
subscribe
, but represents the subscription explicitly as aResource
which returns after the subscriber is subscribed, but before it has started pulling elements. -
abstract
def
subscribers: Stream[F, Int]
Signal of current active subscribers.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
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final
def
##(): Int
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final
def
==(arg0: Any): Boolean
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final
def
asInstanceOf[T0]: T0
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def
clone(): AnyRef
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final
def
eq(arg0: AnyRef): Boolean
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def
equals(arg0: Any): Boolean
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final
def
getClass(): Class[_]
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- @native() @HotSpotIntrinsicCandidate()
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def
hashCode(): Int
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-
def
imap[B](f: (A) ⇒ B)(g: (B) ⇒ A): Topic[F, B]
Returns an alternate view of this
Topic
where its elements are of typeB
, given two functions,A => B
andB => A
. -
final
def
isInstanceOf[T0]: Boolean
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final
def
ne(arg0: AnyRef): Boolean
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final
def
notify(): Unit
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final
def
notifyAll(): Unit
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final
def
synchronized[T0](arg0: ⇒ T0): T0
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def
toString(): String
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-
final
def
wait(arg0: Long, arg1: Int): Unit
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final
def
wait(arg0: Long): Unit
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final
def
wait(): Unit
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Deprecated Value Members
-
def
finalize(): Unit
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- @throws( classOf[java.lang.Throwable] ) @Deprecated
- Deprecated