Consistent and Rendezvous Hashing

// rendezvous hashing: score each node, pick the best
import { createHash } from 'node:crypto';
const score = (key: string, node: string) => createHash('md5').update(key + '|' + node).digest().readUInt32BE(0);
const pick = (key: string, nodes: string[]) => nodes.reduce((best, n) => score(key, n) > score(key, best) ? n : best);

// jump consistent hash (Lamping and Veach, 2014)
function jump(key: bigint, buckets: number): number {
  let b = -1n, j = 0n;
  while (j < BigInt(buckets)) { b = j; key = (key * 2862933555777941757n + 1n) & 0xFFFFFFFFFFFFFFFFn; j = BigInt(Math.floor(Number(b + 1n) * (2 ** 31 / Number((key >> 33n) + 1n)))); }
  return Number(b);
}