time 33 哈希函数

hash.js

/**
    A string hashing function based on Daniel J. Bernstein's popular 'times 33' hash algorithm.
    @param {string} text - String to hash
    @return {number} Resulting number.
*/
function hash(text) {
    'use strict';

    var hash = 5381,
        index = text.length;

    while (index) {
        hash = (hash * 33) ^ text.charCodeAt(--index);
    }

    return hash >>> 0;
}

// refer：https://segmentfault.com/a/1190000013132249（纪念司徒正美君）