Request Pool using Angular

request-pool.js

'use strict';

import  BaseCollection from './data/collections/BaseCollection';
import * as _ from 'lodash';

RequestPool.$inject = ['$q'];

export default function RequestPool($q) {
    function RequestPool(cap) {
        this.cap = cap;
        this.openRequests = 0;
        this.openPool = new BaseCollection();
        this.queuePool = new BaseCollection();
    }

    RequestPool.prototype = {
        cap: 6,
        openRequests: 0,
        openPool: null,
        queuePool: null,

        poolRequest: function() {
            var deferred = $q.defer();
            var _id = _.uniqueId();

            var requestObject = {
                id: _id,
                deferred: deferred
            };

            if (this.openPool.length >= this.cap) {
                this.queuePool.add(requestObject);
            } else {
                this.openPool.add(requestObject);
                deferred.resolve(requestObject);
            }

            return deferred.promise;
        },

        dequeueRequest: function(id) {
            this.openPool.remove(id);

            if (this.queuePool.length > 0  &&
                 this.openPool.length < this.cap) {
                var requestObject = this.queuePool.first();
                this.queuePool.remove(requestObject.id);
                this.openPool.add(requestObject);
                requestObject.deferred.resolve(requestObject);
            }
        },

        close: function() {
            this.queuePool.each(function(poolObject) {
                poolObject.deferred.reject();
            });
            this.queuePool.empty();
        }
    };

    return RequestPool;
};