@Test
public void demonstrateBroadcast() {
final Sink<Author, CompletionStage<Done>> writeAuthors = Sink.ignore();
final Sink<Hashtag, CompletionStage<Done>> writeHashtags = Sink.ignore();
// #flow-graph-broadcast
RunnableGraph.fromGraph(
GraphDSL.create(
b -> {
final UniformFanOutShape<Tweet, Tweet> bcast = b.add(Broadcast.create(2));
final FlowShape<Tweet, Author> toAuthor =
b.add(Flow.of(Tweet.class).map(t -> t.author));
final FlowShape<Tweet, Hashtag> toTags =
b.add(
Flow.of(Tweet.class)
.mapConcat(t -> new ArrayList<Hashtag>(t.hashtags())));
final SinkShape<Author> authors = b.add(writeAuthors);
final SinkShape<Hashtag> hashtags = b.add(writeHashtags);
b.from(b.add(tweets)).viaFanOut(bcast).via(toAuthor).to(authors);
b.from(bcast).via(toTags).to(hashtags);
return ClosedShape.getInstance();
}))
.run(mat);
// #flow-graph-broadcast
}
@Test
public void complexGraph() throws Exception {
// #complex-graph
RunnableGraph.fromGraph(
GraphDSL.create(
builder -> {
final Outlet<Integer> A = builder.add(Source.single(0)).out();
final UniformFanOutShape<Integer, Integer> B = builder.add(Broadcast.create(2));
final UniformFanInShape<Integer, Integer> C = builder.add(Merge.create(2));
final FlowShape<Integer, Integer> D =
builder.add(Flow.of(Integer.class).map(i -> i + 1));
final UniformFanOutShape<Integer, Integer> E = builder.add(Balance.create(2));
final UniformFanInShape<Integer, Integer> F = builder.add(Merge.create(2));
final Inlet<Integer> G = builder.add(Sink.<Integer>foreach(System.out::println)).in();
builder.from(F).toFanIn(C);
builder.from(A).viaFanOut(B).viaFanIn(C).toFanIn(F);
builder.from(B).via(D).viaFanOut(E).toFanIn(F);
builder.from(E).toInlet(G);
return ClosedShape.getInstance();
}));
// #complex-graph
// #complex-graph-alt
RunnableGraph.fromGraph(
GraphDSL.create(
builder -> {
final SourceShape<Integer> A = builder.add(Source.single(0));
final UniformFanOutShape<Integer, Integer> B = builder.add(Broadcast.create(2));
final UniformFanInShape<Integer, Integer> C = builder.add(Merge.create(2));
final FlowShape<Integer, Integer> D =
builder.add(Flow.of(Integer.class).map(i -> i + 1));
final UniformFanOutShape<Integer, Integer> E = builder.add(Balance.create(2));
final UniformFanInShape<Integer, Integer> F = builder.add(Merge.create(2));
final SinkShape<Integer> G = builder.add(Sink.foreach(System.out::println));
builder.from(F.out()).toInlet(C.in(0));
builder.from(A).toInlet(B.in());
builder.from(B.out(0)).toInlet(C.in(1));
builder.from(C.out()).toInlet(F.in(0));
builder.from(B.out(1)).via(D).toInlet(E.in());
builder.from(E.out(0)).toInlet(F.in(1));
builder.from(E.out(1)).to(G);
return ClosedShape.getInstance();
}));
// #complex-graph-alt
}
@Test
public void closedGraph() throws Exception {
// #embed-closed
final RunnableGraph<NotUsed> closed1 = Source.single(0).to(Sink.foreach(System.out::println));
final RunnableGraph<NotUsed> closed2 =
RunnableGraph.fromGraph(
GraphDSL.create(
builder -> {
final ClosedShape embeddedClosed = builder.add(closed1);
return embeddedClosed; // Could return ClosedShape.getInstance()
}));
// #embed-closed
}
public void demonstrateADetachedGraphStage() throws Exception {
// tests:
CompletionStage<Integer> result1 =
Source.from(Arrays.asList(1, 2, 3))
.via(new TwoBuffer<>())
.runFold(0, (acc, n) -> acc + n, mat);
assertEquals(new Integer(6), result1.toCompletableFuture().get(3, TimeUnit.SECONDS));
TestSubscriber.ManualProbe<Integer> subscriber = TestSubscriber.manualProbe(system);
TestPublisher.Probe<Integer> publisher = TestPublisher.probe(0, system);
RunnableGraph<NotUsed> flow2 =
Source.fromPublisher(publisher).via(new TwoBuffer<>()).to(Sink.fromSubscriber(subscriber));
flow2.run(mat);
Subscription sub = subscriber.expectSubscription();
// this happens even though the subscriber has not signalled any demand
publisher.sendNext(1);
publisher.sendNext(2);
sub.cancel();
}