package com.evolutiongaming.kafka.journal.util
import cats.effect._
import cats.effect.concurrent.Deferred
import cats.effect.implicits._
import cats.implicits._
object StartResource {
def apply[F[_] : Concurrent, A, B](
res: Resource[F, A])(
use: A => F[B]
): F[Fiber[F, B]] = {
res.allocated.bracketCase { case (a, release) =>
for {
released <- Deferred[F, Unit]
fiber <- Concurrent[F].start {
use(a).guarantee {
release.guarantee {
released.complete(())
}
}
}
} yield {
new Fiber[F, B] {
def cancel = fiber.cancel *> released.get
def join = fiber.join
}
}
} { case ((_, release), exitCase) =>
exitCase match {
case ExitCase.Completed => ().pure[F]
case _: ExitCase.Error[Throwable] => release
case ExitCase.Canceled => release
}
}
}
}
