Function _insert

lib/internal/queue.js:23–51

(data, insertAtFront, callback)

    var workersList = [];

    function _insert(data, insertAtFront, callback) {
        if (callback != null && typeof callback !== 'function') {
            throw new Error('task callback must be a function');
        }
        q.started = true;
        if (!isArray(data)) {
            data = [data];
        }
        if (data.length === 0 && q.idle()) {
            // call drain immediately if there are no tasks
            return setImmediate(function() {
                q.drain();
            });
        }

        for (var i = 0, l = data.length; i < l; i++) {
            var item = {
                data: data[i],
                callback: callback || noop
            };

            if (insertAtFront) {
                q._tasks.unshift(item);
            } else {
                q._tasks.push(item);
            }
        }
        setImmediate(q.process);
    }

    function _next(tasks) {
        return rest(function(args){