hashCode.js

/**
 * Generates a hash code from the given string using the `cyrb53` hashing
 * algorithm.
 * 
 * @param {string} str
 * @param {number=} seed
 */
export const hashCode = (str, seed = 0) => {

    let h1 = 0xdeadbeef ^ seed;
    let h2 = 0x41c6ce57 ^ seed;

    for (let i = 0, ch; i < str.length; i++) {
        ch = str.charCodeAt(i);
        h1 = Math.imul(h1 ^ ch, 0x9e3779b1);
        h2 = Math.imul(h2 ^ ch, 0x5f356495);
    }

    h1 = Math.imul(h1 ^ (h1 >>> 16), 0x85ebca6b) ^ Math.imul(h2 ^ (h2 >>> 13), 0xc2b2ae35);
    h2 = Math.imul(h2 ^ (h2 >>> 16), 0x85ebca6b) ^ Math.imul(h1 ^ (h1 >>> 13), 0xc2b2ae35);

    return 0x100000000 * (0x1fffff & h2) + (h1 >>> 0);
};