function throttle()

in public/data/asset/data/draggable.js [152:224]
18 lines of code
4 McCabe index (conditional complexity)

    function throttle(fn, delay, trailing, debounce) {

        var currCall = (new Date()).getTime();
        var lastCall = 0;
        var lastExec = 0;
        var timer = null;
        var diff;
        var scope;
        var args;
        var isSingle = typeof fn === 'function';
        delay = delay || 0;

        if (isSingle) {
            return createCallback();
        }
        else {
            var ret = [];
            for (var i = 0; i < fn.length; i++) {
                ret[i] = createCallback(i);
            }
            return ret;
        }

        function createCallback(index) {

            function exec() {
                lastExec = (new Date()).getTime();
                timer = null;
                (isSingle ? fn : fn[index]).apply(scope, args || []);
            }

            var cb = function () {
                currCall = (new Date()).getTime();
                scope = this;
                args = arguments;
                diff = currCall - (debounce ? lastCall : lastExec) - delay;

                clearTimeout(timer);

                if (debounce) {
                    if (trailing) {
                        timer = setTimeout(exec, delay);
                    }
                    else if (diff >= 0) {
                        exec();
                    }
                }
                else {
                    if (diff >= 0) {
                        exec();
                    }
                    else if (trailing) {
                        timer = setTimeout(exec, -diff);
                    }
                }

                lastCall = currCall;
            };

            /**
             * Clear throttle.
             * @public
             */
            cb.clear = function () {
                if (timer) {
                    clearTimeout(timer);
                    timer = null;
                }
            };

            return cb;
        }
    }