retry.scala

  
  private val bucket = new NanoTimeTokenBucket(1, 1250.milliseconds.toNanos)
  def of = synchronized(bucket.offer(1).nanos.toMillis) 
  def req[T](uri: Uri, opWhenSuccess: HttpResponse => Source[T, NotUsed]): Future[Source[T, NotUsed]] = Future {
    RestartSource.withBackoff(200.millis, 30.seconds, 2.0, 3) { () =>
      Source.fromFutureSource {
        Thread.sleep(of)
        Http().singleRequest(HttpRequest(uri = uri)).map { res =>
          if (res.status.intValue() == 200) {
            res.headers.find(_.is("retry-after")).foreach(h => logger.debug(h.toString()))
            res.headers.find(_.is("x-app-rate-limit-count")).foreach(h => logger.debug(h.toString()))
            opWhenSuccess(res)
          } else {
            logger.debug(res.toString())
            Source.empty
          }
        }
      }
    }
  }