@Test
public void demonstrateSlowProcessing() {
// #tweets-slow-consumption-dropHead
tweets
.buffer(10, OverflowStrategy.dropHead())
.map(t -> slowComputation(t))
.runWith(Sink.ignore(), mat);
// #tweets-slow-consumption-dropHead
}
@Test
public void mustBeAbleToUseQueue() throws Exception {
final Pair<SourceQueueWithComplete<String>, CompletionStage<List<String>>> x =
Flow.of(String.class)
.runWith(Source.queue(2, OverflowStrategy.fail()), Sink.seq(), materializer);
final SourceQueueWithComplete<String> source = x.first();
final CompletionStage<List<String>> result = x.second();
source.offer("hello");
source.offer("world");
source.complete();
assertEquals(
result.toCompletableFuture().get(3, TimeUnit.SECONDS), Arrays.asList("hello", "world"));
}
@Test
public void mustBeAbleToUseBuffer() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final List<String> input = Arrays.asList("A", "B", "C");
final CompletionStage<List<String>> future =
Source.from(input)
.buffer(2, OverflowStrategy.backpressure())
.grouped(4)
.runWith(Sink.<List<String>>head(), materializer);
List<String> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals(input, result);
}
@Test
public void mustBeAbleToUseActorRefSource() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Source<Integer, ActorRef> actorRefSource = Source.actorRef(10, OverflowStrategy.fail());
final ActorRef ref =
actorRefSource
.to(
Sink.foreach(
new Procedure<Integer>() {
public void apply(Integer elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
}))
.run(materializer);
ref.tell(1, ActorRef.noSender());
probe.expectMsgEquals(1);
ref.tell(2, ActorRef.noSender());
probe.expectMsgEquals(2);
}