leagueapi/lib/rateLimiter.js

Wrapper for the League of Legends API

'use strict';

var RateLimiter = (function() {
    var RateLimiter = function(maxOps, interval, allowBursts) {
        this._maxRate = allowBursts ? maxOps : maxOps / interval;
        this._interval = interval;
        this._allowBursts = allowBursts;

        this._numOps = 0;
        this._start = new Date().getTime();
        this._queue = [];
    };

    RateLimiter.prototype.schedule = function(fn) {
        var that = this,
        rate = 0,
        now = new Date().getTime(),
        elapsed = now - this._start;

        if (elapsed > this._interval) {
            this._numOps = 0;
            this._start = now;
        }

        rate = this._numOps / (this._allowBursts ? 1 : elapsed);

        if (rate < this._maxRate) {
            if (this._queue.length === 0) {
                this._numOps++;
                fn();
            } else {
                if (fn) {
                    this._queue.push(fn);
                }
                this._numOps++;
                this._queue.shift()();
            }
        } else {
            if (fn){
                this._queue.push(fn);
            }

            setTimeout(function() {
                that.schedule();
            }, 1 / this._maxRate);
        }
    };

    return RateLimiter;
})();

module.exports = RateLimiter;