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javascriptweb-workerdenoarraybuffer

Convert Array of primitives to ArrayBuffer

I am trying to use Web Workers, and I noticed that to improve performance you can use "transferable" objects in postMessage

https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers

In Deno, transferable object means ArrayBuffer, but how to transform an array variable to ArrayBuffer ?

my use case is sending array of around 10k elements to the web worker, so I'd like to not copy it if possible.

Solution

  • An array with strings could technically be transferred by creating a binary array from a serialized string:

    // sender
arr = [1, 2, 'three']
bytes = new TextEncoder().encode(arr.join('|'))
postMessage(bytes, [bytes.buffer])

// receiver
onmessage = event => new TextDecoder().decode(event.data).split('|')

    However, standard serialization should outperform that conversion/transfer:

    postMessage(arr)                 // sender
onmessage = event => event.data  // receiver