如何使用 Akka 延迟一秒限制 Futures

Question

我有 URI 列表，我想请求每个 URI，中间有 1 秒的延迟。我怎样才能做到这一点？

val uris: List[String] = List()
// How to make these URIs resolve 1 second apart?
val responses: List[Future[Response]] = uris.map(httpRequest(_))

Answer 1

您可以Source从 URI 列表创建 Akka Streams ，然后throttle将每个 URI 转换为Future[Response]：

def httpRequest(uri: String): Future[Response] = ???

val uris: List[String] = ???

val responses: Future[Seq[Response]] =
  Source(uris)
    .throttle(1, 1 second)
    .mapAsync(parallelism = 1)(httpRequest)
    .runWith(Sink.seq[Response])