mergePrioritizedN
Merge multiple sources with priorities.
Signature
Description
Merge multiple sources. Prefer sources depending on priorities if all sources have elements ready. If a subset of all sources have elements ready the relative priorities for those sources are used to prioritize. For example, when used with only three sources sourceA
, sourceB
and sourceC
, the sourceA
has a probability of (priorityOfA) / (priorityOfA + priorityOfB + priorityOfC)
of being prioritized and similarly for the rest of the sources. The priorities for each source must be positive integers.
Example
- Scala
-
source
import akka.stream.scaladsl.{ Sink, Source } val sourceA = Source(List(1, 2, 3, 4)) val sourceB = Source(List(10, 20, 30, 40)) val sourceC = Source(List(100, 200, 300, 400)) Source .mergePrioritizedN(List((sourceA, 9900), (sourceB, 99), (sourceC, 1)), eagerComplete = false) .runWith(Sink.foreach(println)) // prints e.g. 1, 100, 2, 3, 4, 10, 20, 30, 40, 200, 300, 400 since both sources have their first element ready and // the left sourceA has higher priority - if both sources have elements ready, sourceA has a 99% chance of being picked next // while sourceB has a 0.99% chance and sourceC has a 0.01% chance
- Java
-
source
Source<Integer, NotUsed> sourceA = Source.from(Arrays.asList(1, 2, 3, 4)); Source<Integer, NotUsed> sourceB = Source.from(Arrays.asList(10, 20, 30, 40)); Source<Integer, NotUsed> sourceC = Source.from(Arrays.asList(100, 200, 300, 400)); List<Pair<Source<Integer, ?>, Integer>> sourcesAndPriorities = Arrays.asList(new Pair<>(sourceA, 9900), new Pair<>(sourceB, 99), new Pair<>(sourceC, 1)); Source.mergePrioritizedN(sourcesAndPriorities, false).runForeach(System.out::println, system); // prints e.g. 1, 100, 2, 3, 4, 10, 20, 30, 40, 200, 300, 400 since both sources have their // first element ready and // the left sourceA has higher priority - if both sources have elements ready, sourceA has a 99% // chance of being picked next // while sourceB has a 0.99% chance and sourceC has a 0.01% chance
Reactive Streams semantics
emits when one of the inputs has an element available, preferring inputs based on their priorities if multiple have elements available
backpressures when downstream backpressures
completes when all upstreams complete (or when any upstream completes if eagerComplete=true
.)
Cancels when downstream cancels