feat(mv3): ➕ Adding hash function to generate predict…

[whizzzkid]

Fixes: #1182 (comment)

Introduces: npmjs.com/package/fast-hash-code

[SgtPooki]

Approved with concern

[SgtPooki]

This seems reasonable, but the link provided by fast-hash-code to the implementation reasoning is no longer available. It makes me wonder about collisions. webCrypto.subtle.digest should do what we want and is available in service workers, is there a reason we didn't use that?

does id need to be a number?

[whizzzkid]

id needs to be a number, that too >=1. https://developer.chrome.com/docs/extensions/reference/declarativeNetRequest/#type-Rule

I can do something like:

function id (text = 'hello world') {
  // new Int8Array(await crypto.subtle.digest('SHA-1', new TextEncoder().encode('hello world'))).reduce((a, v) => a + v, 0)
  
  const digest = await crypto.subtle.digest('SHA-1', new TextEncoder().encode(text)
  const digestArr = new Int8Array(digest)
  const sum = digestArr.reduce((a, v) => a + v, 0)
  return Math.abs(sum) // always positive.
}

will that be better? I still have no clue about collisions. The collisions earlier were in the space of 30k values, I think the package does a homogeneous distribution.