ZIO learning - race to get the fastest response and immediately stop others / published by https://github.com/dacr/code-examples-manager #0eb518fe-7323-4858-9a50-7137d90eb998/91bdcf36efd85b7ce3ffaadbc5744e5e6975ae5d

zio-learning-7-concurrency-3-race.sc

// summary : ZIO learning - race to get the fastest response and immediately stop others
// keywords : scala, zio, learning, pure-functional, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 0eb518fe-7323-4858-9a50-7137d90eb998
// created-on : 2021-04-06T11:07:45+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "dev.zio::zio:2.0.13"
// ---------------------
import zio.*

object ThatApp extends ZIOAppDefault {

  def sha(that: String, algo: String) = {
    for {
      md          <- ZIO.attempt(java.security.MessageDigest.getInstance(algo))
      digest      <- ZIO.attempt(md.digest(that.getBytes))
      bigInt      <- ZIO.attempt(new java.math.BigInteger(1, digest))
      hashedString = bigInt.toString(16)
    } yield hashedString
  }

  def sha1(that: String) = sha(that, "SHA-1")

  def sha256(that: String) = sha(that, "SHA-256")

  val message = "Hello world"

  val racedTasks = sha256(message).race(sha1(message))

  val run = for {
    result <- racedTasks
    _      <- Console.printLine(result)
  } yield ()
}
// -------------------------------------------------------------

ThatApp.main(Array.empty)