@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 partialGraph() throws Exception {
// #partial-graph
final Graph<FlowShape<Integer, Integer>, NotUsed> partial =
GraphDSL.create(
builder -> {
final UniformFanOutShape<Integer, Integer> B = builder.add(Broadcast.create(2));
final UniformFanInShape<Integer, Integer> C = builder.add(Merge.create(2));
final UniformFanOutShape<Integer, Integer> E = builder.add(Balance.create(2));
final UniformFanInShape<Integer, Integer> F = builder.add(Merge.create(2));
builder.from(F.out()).toInlet(C.in(0));
builder.from(B).viaFanIn(C).toFanIn(F);
builder
.from(B)
.via(builder.add(Flow.of(Integer.class).map(i -> i + 1)))
.viaFanOut(E)
.toFanIn(F);
return new FlowShape<Integer, Integer>(B.in(), E.out(1));
});
// #partial-graph
// #partial-use
Source.single(0).via(partial).to(Sink.ignore());
// #partial-use
// #partial-flow-dsl
// Convert the partial graph of FlowShape to a Flow to get
// access to the fluid DSL (for example to be able to call .filter())
final Flow<Integer, Integer, NotUsed> flow = Flow.fromGraph(partial);
// Simple way to create a graph backed Source
final Source<Integer, NotUsed> source =
Source.fromGraph(
GraphDSL.create(
builder -> {
final UniformFanInShape<Integer, Integer> merge = builder.add(Merge.create(2));
builder.from(builder.add(Source.single(0))).toFanIn(merge);
builder.from(builder.add(Source.from(Arrays.asList(2, 3, 4)))).toFanIn(merge);
// Exposing exactly one output port
return new SourceShape<Integer>(merge.out());
}));
// Building a Sink with a nested Flow, using the fluid DSL
final Sink<Integer, NotUsed> sink =
Flow.of(Integer.class).map(i -> i * 2).drop(10).named("nestedFlow").to(Sink.head());
// Putting all together
final RunnableGraph<NotUsed> closed = source.via(flow.filter(i -> i > 1)).to(sink);
// #partial-flow-dsl
}