ZIO和多个回调

Question

我对使用ZIO非常陌生。我目前正在用Scala编写一个密码交易机器人，同时我也在尝试学习ZIO。现在我正在打开一个websocket，这个websocket会给出多个回调，直到它被关闭，我正在努力将其集成到我的代码中。我当前的代码：

object Main extends zio.App with Logging {
   def run(args: List[String]): URIO[Any with Console, ExitCode] = Configuration.getConfiguration.fold(onError, start).exitCode

   private val interval: CandlestickInterval = CandlestickInterval.ONE_MINUTE

   private def onError(exception: ConfigurationException): ZIO[Any, Throwable, Unit]  = {
     logger.info("Could not initialize traderbot!")
     logger.error(exception.getMessage)
     IO.succeed()
   }

   private final def start(configuration: Configuration): ZIO[Any, Throwable, Unit] = {
      for {
        binanceClient <- IO.succeed(BinanceApiClientFactory.newInstance(configuration.apiKey, configuration.secret))
        webSocketClient <- IO.succeed(binanceClient.newWebSocketClient())
        candlesticks <- Task.effectAsync[CandlestickEvent] {
          callback =>
            webSocketClient.onCandlestickEvent(
            "adaeur",
            interval, d => callback(IO.succeed(d))
          )
        })
        // TODO Calculate RSI from candlesticks.
   } yield candlesticks
 }
}

我想继续接收烛台事件，并保持功能正常。我看到了一些关于Zio Streams的东西，但我找不到处理重复回调的示例，而且很容易理解。现在我不能使用我的Candlestick代码来进行理解。

耽误您时间，实在对不起!

Answer 1

不幸的是，在使用effectAsync时，ZIO不能处理多个回调，因为数据类型是基于单个成功或失败值的。

不过，您可以使用ZStream，它有一个类似形状的运算符，可以多次调用：

private final def start(configuration: Configuration): ZStream[Any, Throwable, Unit] = {
  val candlesticks = ZStream.unwrap(
    IO.effectTotal {
      val client = BinanceApiClientFactory
        .newInstance(configuration.apiKey, configuration.secret)
        .newWebSocketClient()

      // This variant accepts a return value in the `Left` which 
      // is called when during shutdown to make sure that the websocket is 
      // cleaned up
      ZStream.effectAsyncInterrupt { cb => 
        val closeable = webSocketClient.onCancelstickEvent(
          "adaeur",
          interval,
          d => cb(IO.succeed(d)
        ) 

        Left(UIO(closeable.close()))
      }
  )

  for {
    candlestick <- candlesticks
    // TODO Calculate RSI from candlesticks.
  } yield ()
}