crystal.Deglitcher.scala Maven / Gradle / Ivy
// Copyright (c) 2016-2023 Association of Universities for Research in Astronomy, Inc. (AURA)
// For license information see LICENSE or https://opensource.org/licenses/BSD-3-Clause
package crystal
import cats.effect.Ref
import cats.effect.Temporal
import cats.syntax.all.*
import fs2.Pipe
import fs2.Stream
import scala.concurrent.duration.FiniteDuration
final class Deglitcher[F[_]] private (
waitUntil: Ref[F, FiniteDuration],
timeout: FiniteDuration
)(using F: Temporal[F]) {
def throttle: F[Unit] =
F.monotonic.flatMap(now => waitUntil.set(now + timeout))
def debounce[A]: Pipe[F, A, A] =
_.switchMap { a =>
Stream.eval {
def wait: F[Unit] =
(waitUntil.get, F.monotonic).flatMapN { (waitUntil, now) =>
if (waitUntil > now)
F.sleep(waitUntil - now) *> wait
else F.unit
}
wait.as(a)
}
}
}
object Deglitcher {
def apply[F[_]](timeout: FiniteDuration)(using F: Temporal[F]): F[Deglitcher[F]] =
F.monotonic.flatMap(F.ref(_)).map(new Deglitcher(_, timeout))
}