42 ms·

I wonder if Swift's AsyncAwait could be used in such a way.

• Ryuuke5 4y ago
  Sure it's possible, we need to await for the Task if it already exists on the dictionary, for example we could imagine writing something like this inside an actor to make it threadSafe. private var tasksDictionary: Dictionary<String, Task<Data, Error>> func getData(at urlString: String) async throws -> Data { if let currentTask = tasksDictionary[urlString] { return await currentTask.value } let currentTask = Task { return try await URLSession.shared.data(from: URL(string:urlString)!) } tasksDictionary[urlString] = currentTask let result = await currentTask.value tasksDictionary[urlString] = nil return result }
  • afro88 4y ago
    Great! So much nicer than the Combine (or Rx) version.
  • ninkendo 4y ago
    Hmm, why set `taskDictionary[urlString] = nil` at the bottom there? If the whole point is to cache the result, isn't the point to leave the value there for other requests to pick it up?
    • Ryuuke5 4y ago
      Yup, nice catch, no need to reset it to nil if you wanna keep it in memory indefinitely. I guess making it nil can be also used if you don't wanna make the same request when there is one already in flight, in case you have a 403 error and need to request a refresh token, you don't wanna make two simultaneous requests, but you also don't wanna catch it indefinitely either.