Why is crypto.subtle.digest designed to return a promise?

Every other system I’ve ever worked with has the signature hash(bytes) => bytes, yet whatever committee designed the Subtle Crypto API decided that the browser version should return a promise. Why? I’ve looked around but I’ve never found any discussion on the motivation behind that.

  • Technus@lemmy.zip
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    4 months ago

    It executes on a native thread in the background. That way it doesn’t stall the Javascript execution loop, even if you give it a gigabyte of data to hash.

    • Ethan@programming.devOP
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      4 months ago

      async/await infecting all of my code, being unable to create a get myField() method that involves a hash calculation. It may be standard to do heavy lifting concurrently, but async hash functions are certainly not standard in any of the languages I’ve used (which is quite a few).

        • macniel@feddit.de
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          4 months ago

          Given the nature of JS running only on a single thread. Promises/asynchronity is the only way to keep the browser from locking up.

          Thus insisting on any other way is a major flaw in the developer not the language.

  • macniel@feddit.de
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    4 months ago

    its a good idea to be as non blocking as possible especially on time and resource consuming tasks like IO, cryptography, …

    just use await in an async function.

    • Ethan@programming.devOP
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      4 months ago

      just use await in an async function.

      Sure, I’ll just put await and async everywhere. Oh wait, I can’t. A constructor can’t be async so now I need to restructure my code to use async factories instead of constructors. Wonderful…

      • macniel@feddit.de
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        4 months ago

        Sounds like an architectural issue to begin with. A constructor shouldn’t do the heavy lifting to begin with.

          • macniel@feddit.de
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            4 months ago

            The API doesn’t restrict the amount of bytes to be hashed. So yeah it’s still heavy lifting.

            Trigger a loading event after the constructor is finished that the view model takes to calculate your hash.