const fnv1a52 = (str) => {
  const len = str.length;
  let i = 0, t0 = 0, v0 = 8997, t1 = 0, v1 = 33826, t2 = 0, v2 = 40164, t3 = 0, v3 = 52210;
  while (i < len) {
    v0 ^= str.charCodeAt(i++);
    t0 = v0 * 435;
    t1 = v1 * 435;
    t2 = v2 * 435;
    t3 = v3 * 435;
    t2 += v0 << 8;
    t3 += v1 << 8;
    t1 += t0 >>> 16;
    v0 = t0 & 65535;
    t2 += t1 >>> 16;
    v1 = t1 & 65535;
    v3 = t3 + (t2 >>> 16) & 65535;
    v2 = t2 & 65535;
  }
  return (v3 & 15) * 281474976710656 + v2 * 4294967296 + v1 * 65536 + (v0 ^ v3 >> 4);
};
const etag = (payload, weak = false) => {
  const prefix = weak ? 'W/"' : '"';
  return prefix + fnv1a52(payload).toString(36) + payload.length.toString(36) + '"';
};
export {
  etag,
  fnv1a52
};