rocket.chat.mqtt/node_modules/shortid/lib/decode.js

It's a MQTT Server, using redis to scale horizontally.

'use strict';
var alphabet = require('./alphabet');

/**
 * Decode the id to get the version and worker
 * Mainly for debugging and testing.
 * @param id - the shortid-generated id.
 */
function decode(id) {
    var characters = alphabet.shuffled();
    return {
        version: characters.indexOf(id.substr(0, 1)) & 0x0f,
        worker: characters.indexOf(id.substr(1, 1)) & 0x0f
    };
}

module.exports = decode;