Прототип новой функциональности на F# глазами C#-программиста

diskStatusChecker.fsx

open System
open System.Threading

let rnd = Random(Environment.TickCount)

let disks = [ 1; 2; 3; 4 ]

type Status =
    | Fail of int
    | Normal of int

type LastSend = int * DateTime

let getStatus d =
    if rnd.Next(100) < 50 then Fail d else Normal d

let reSendAfter = DateTime.Now.AddSeconds(70.)


let createTimerAndObservable timerInterval (stopAfter: int) =
    let timer =
        new System.Timers.Timer(float timerInterval)

    timer.AutoReset <- true
    let observable = timer.Elapsed

    let task =
        async {
            timer.Start()
            do! Async.Sleep stopAfter
            timer.Stop()
        }

    (task, observable)

let timer, timerEventStream = createTimerAndObservable 5000 60000

let sendMessage s = printfn "%s" s

let diskAgent =
    MailboxProcessor<Status>
        .Start(fun inbox ->

              let rec messageLoop (lastChecks) =
                  async {
                      let! msg = inbox.Receive()

                      match msg with
                      | Fail d ->
                          if lastChecks
                             |> List.exists (fun (disk, time) -> disk = d && time < reSendAfter) then
                              printfn "Disk %d is fail. Skip send message" d
                          else
                              sprintf "Disk %d is fail. Required replacement." d
                              |> sendMessage
                              return! messageLoop
                                          (lastChecks
                                           |> List.filter (fun (disk, _) -> disk <> d)
                                           |> List.append [ (d, DateTime.Now) ])
                      | Normal d ->
                          printfn "Disk %d is normal" d
                          return! messageLoop
                                      (lastChecks
                                       |> List.filter (fun (disk, _) -> disk <> d))
                  }

              messageLoop ([]))


timerEventStream
|> Observable.subscribe (fun _ ->
    printfn "%A check disks status" DateTime.Now
    for d in disks do
        getStatus d |> diskAgent.Post)

Async.RunSynchronously timer

Идея в том, что сообщение о сбое диска должно быть отправлено один раз до наступления некоторого времени.