https://github.com/calebkleveter/nioasync

Combines SwiftCoroutines and Swift NIO for Async/Await support with EventLoopFutures
https://github.com/calebkleveter/nioasync

async-await coroutines swift swift-nio unstable

Last synced: 3 months ago
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Combines SwiftCoroutines and Swift NIO for Async/Await support with EventLoopFutures

• Host: GitHub
• URL: https://github.com/calebkleveter/nioasync
• Owner: calebkleveter
• License: mit
• Created: 2020-01-21T22:59:11.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2020-03-30T15:09:41.000Z (almost 5 years ago)
• Last Synced: 2023-10-20T18:39:11.512Z (over 1 year ago)
• Topics: async-await, coroutines, swift, swift-nio, unstable
• Language: Swift
• Size: 54.7 KB
• Stars: 5
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# NIOAsync

**:warning: `setjmp` and `longjpm` used to implement SwiftCoroutine are generally considered to be undefined behaviour. It's probably a bad idea to use this project for anything other than experimentation. Use at your own risk.**

## :package: Getting Started

Oh, you're still reading, huh? Alright, I guess I'll get you up to speed. This project is pretty small, so there isn't much to it. Start by adding it as a dependency to your SPM project:

```swift

.package(url: "https://github.com/calebkleveter/NIOAsync.git", from: "0.1.0")

```

Then run `swift package update`, or feel smug that you have Xcode 11 and wait for it to install.

## :hammer: API

There are really 2 methods that this package provides. The first is `EventLoop.async(_:)`:

```swift

let result: EventLoopFuture = eventLoop.async {

    return someReallyLongAsyncOperation()

}

```

This method starts a coroutine and runs the provided closure inside of that coroutine. The value that is returned from the closure is the result that you get in the `EventLoopFuture` that is returned. The closure also allows you to throw errors. If that happens, your `EventLoopFuture` will be failed.

The second piece to the puzzel is `EventLoopFuture.await()`:

```swift

let user = try User.query(on: database).first().await()

```

Note that this method is different from the `wait` method provided by NIO. You can only call it inside the closure of an `async` call (or inside any other coroutine that you happen to have started). It waits for the future result and returns it, without blocking the current thread because you are in a coroutine.

In the end, your code might look a little like this:

```swift

eventLoop.async {

    guard let user = try User.query(on: database).filter(\.$id == id).first().await() else {

        throw Abort(.notFound)

    }

    guard let id = user.id else {

        throw Abort(.internalServerError, reason: "All saved models must have an ID")

    }

    

    return try s3Client.fetch("\(id)/profile-image.png").await()

}

```

## :page_facing_up: License

All code, documents, and other resources contained in this repository is under the MIT license agreement.