@lukalabs/esbuild-styled-components/hash.js

esbuild styled-components plugin to replace styled-components/macro

/**
 * JS Implementation of MurmurHash2
 *
 * @author <a href="mailto:gary.court@gmail.com">Gary Court</a>
 * @see http://github.com/garycourt/murmurhash-js
 * @author <a href="mailto:aappleby@gmail.com">Austin Appleby</a>
 * @see http://sites.google.com/site/murmurhash/
 *
 * @param {string} str ASCII only
 * @return {string} Base 36 encoded hash result
 */
function murmurhash2_32_gc(str) {
  let l = str.length
  let h = l
  let i = 0
  let 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
  } // forgive existing code

  /* eslint-disable no-fallthrough */ 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)
  }
  /* eslint-enable no-fallthrough */

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

  return (h >>> 0).toString(36)
}

module.exports = murmurhash2_32_gc