adapting opensubtitles hashing algorithm to webtorrent stream

I'm trying to make the OpenSubtitles hashing algorithm work on web torrent stream.

This is the official implementation that I tried to copy: https://trac.opensubtitles.org/projects/opensubtitles/wiki/HashSourceCodes#Javascript

This is my code:

import { pipe } from "gamla";

const initLongs = (fileLength) => {
  const longs = [];
  let temp = fileLength;
  for (let i = 0; i < 8; i++) {
    longs[i] = temp & 255;
    temp = temp >> 8;
  }
  return longs;
};

const read = (stream) =>
  new Promise((resolve, reject) => {
    const bufs = [];
    stream
      .on("data", (data) => {
        bufs.push(data);
      })
      .on("end", () => {
        resolve(Buffer.concat(bufs));
      })
      .on("error", reject);
  });

const binl2hex = (a) => {
  var b = 255,
    d = "0123456789abcdef",
    e = "",
    c = 7;

  a[1] += a[0] >> 8;
  a[0] = a[0] & b;
  a[2] += a[1] >> 8;
  a[1] = a[1] & b;
  a[3] += a[2] >> 8;
  a[2] = a[2] & b;
  a[4] += a[3] >> 8;
  a[3] = a[3] & b;
  a[5] += a[4] >> 8;
  a[4] = a[4] & b;
  a[6] += a[5] >> 8;
  a[5] = a[5] & b;
  a[7] += a[6] >> 8;
  a[6] = a[6] & b;
  a[7] = a[7] & b;
  for (d, e, c; c > -1; c--) {
    e += d.charAt((a[c] >> 4) & 15) + d.charAt(a[c] & 15);
  }
  return e;
};

const chunkSize = 64 * 1024;

const process =
  (fileTorrent, [start, end]) =>
  async (longs) => {
    const buffer = await read(
      await fileTorrent.createReadStream({ start, end })
    );
    let c = 0;
    for (const byte of buffer) {
      longs[(c + 8) % 8] += byte;
      c++;
    }
    return longs;
  };

export const computeHash = (fileTorrent) =>
  pipe(
    initLongs,
    process(fileTorrent, [0, chunkSize - 1]),
    process(fileTorrent, [
      fileTorrent.length - chunkSize,
      fileTorrent.length - 1,
    ]),
    binl2hex,
  )(fileTorrent.length);

It doesn't seem to be working (outputting hashes but no results for them in OpenSubtitles). I can't figure out why.

binl2hex is an exact copy so the problem is probably befire converting to hex.

Note that the slicing on the stream should be inclusive on both sides, and I did check I'm getting a buffer of a correct size.

Turns out it does work. The parameter I was using for the call to opensubtitles was hash instead of movieHash.