JavaScript Consistent Hash

consistentHash.js

function makeLinearCongruentialGenerator(seed) {
    const m = Math.pow(2, 31) - 1;
    const a = 16807;
    const c = 0;

    let z = seed;
    return function lcg() {
        z = (a * z + c) % m;
        return z / m;
    }
}

export default function consistentHash(value, buckets) {
    const lcg = makeLinearCongruentialGenerator(value);

    let prev;
    let next = 0;

    do {
        prev = next;
        next = Math.floor((prev + 1) / lcg());
    } while (next < buckets);

    return prev;
}