saepequia/src/slugify.ts

A simple, maximally extensible, dependency minimized framework for building modern Ethereum dApps

/**
 * This file contains a utility to generate hashes to be used as generated class names
 */

/* eslint-disable no-bitwise, default-case, no-param-reassign, prefer-destructuring */

/**
 * murmurhash2 via https://gist.github.com/raycmorgan/588423
 */

function doHash(str: string, seed: number = 0) {
  const m = 0x5bd1e995;
  const r = 24;
  let h = seed ^ str.length;
  let length = str.length;
  let currentIndex = 0;

  while (length >= 4) {
    let k = UInt32(str, currentIndex);

    k = Umul32(k, m);
    k ^= k >>> r;
    k = Umul32(k, m);

    h = Umul32(h, m);
    h ^= k;

    currentIndex += 4;
    length -= 4;
  }

  switch (length) {
    case 3:
      h ^= UInt16(str, currentIndex);
      h ^= str.charCodeAt(currentIndex + 2) << 16;
      h = Umul32(h, m);
      break;

    case 2:
      h ^= UInt16(str, currentIndex);
      h = Umul32(h, m);
      break;

    case 1:
      h ^= str.charCodeAt(currentIndex);
      h = Umul32(h, m);
      break;
  }

  h ^= h >>> 13;
  h = Umul32(h, m);
  h ^= h >>> 15;

  return h >>> 0;
}

function UInt32(str: string, pos: number) {
  return (
    str.charCodeAt(pos++) +
    (str.charCodeAt(pos++) << 8) +
    (str.charCodeAt(pos++) << 16) +
    (str.charCodeAt(pos) << 24)
  );
}

function UInt16(str: string, pos: number) {
  return str.charCodeAt(pos++) + (str.charCodeAt(pos++) << 8);
}

function Umul32(n: number, m: number) {
  n |= 0;
  m |= 0;
  const nlo = n & 0xffff;
  const nhi = n >>> 16;
  const res = (nlo * m + (((nhi * m) & 0xffff) << 16)) | 0;
  return res;
}

function slugify(code: string) {
  return doHash(code).toString(36);
}

export default slugify;