src/utils/murmurHash.js
function murmurhash(str) {
  let l = str.length | 0, h = l | 0, i = 0, k;

  while (l >= 4) {
    k = ((str.charCodeAt(i) & 0xff)) | ((str.charCodeAt(++i) & 0xff) << 8) 
      | ((str.charCodeAt(++i) & 0xff) << 16) | ((str.charCodeAt(++i) & 0xff) << 24);

    k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));
    k ^= k >>> 24;
    k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));

    h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16)) ^ k;

    l -= 4;
    ++i;
  }

  switch (l) {
    case 3: h ^= (str.charCodeAt(i + 2) & 0xff) << 16;
    case 2: h ^= (str.charCodeAt(i + 1) & 0xff) << 8;
    case 1: h ^= (str.charCodeAt(i) & 0xff);
            h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
  }

  h ^= h >>> 13;
  h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
  h ^= h >>> 15;

  return h >>> 0;
}
function murmurhash(str) {
  let l = str.length | 0, h = l | 0, i = 0, k;

  while (l >= 4) {
    k = ((str.charCodeAt(i) & 0xff)) | ((str.charCodeAt(++i) & 0xff) << 8) 
      | ((str.charCodeAt(++i) & 0xff) << 16) | ((str.charCodeAt(++i) & 0xff) << 24);

    k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));
    k ^= k >>> 24;
    k = (((k & 0xffff) * 0x5bd1e995) + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16));

    h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16)) ^ k;

    l -= 4;
    ++i;
  }

  switch (l) {
    case 3: h ^= (str.charCodeAt(i + 2) & 0xff) << 16;
    case 2: h ^= (str.charCodeAt(i + 1) & 0xff) << 8;
    case 1: h ^= (str.charCodeAt(i) & 0xff);
            h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
  }

  h ^= h >>> 13;
  h = (((h & 0xffff) * 0x5bd1e995) + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16));
  h ^= h >>> 15;

  return h >>> 0;
}
Source: https://github.com/garycourt/murmurhash-js/blob/master/murmurhash2_gc.js