Consume an ajax request in Node.js without blocking the browser request

service-request.js

var cache = require("./cache-service");
var http = require("./http-monitor");
var NOT_READY = { statusCode:202, data:"" };


function doRequest(serviceID, httpReq, serviceResults){
	var httpRes = { //overrides httpRes.json() dispatches data without blocking the browser
		json:function(statusCode, data){
			if (arguments.length === 1){
				data = statusCode;
				statusCode = 200;
			}
			if (!httpReq.completed) { 
				serviceResults[serviceID] = { //if data is available save it
						statusCode: statusCode,
						data: data
				}
			}
		}
	};
	if (!cache[serviceID](httpReq, httpRes)){ //check cache, if data is not available, request service	
		http[serviceID](httpReq, httpRes);
	}
}

exports = module.exports = {
	test: function(httpReq, httpRes){ //this call is going to ask for two web services
		var serviceResults = {
			"getClients": NOT_READY, //by default we assume service data won't be available
			"getSales": NOT_READY 
		};
		httpReq.completed = false;
		//List of service requests
		doRequest("getClients", httpReq, serviceResults); //request service data
		doRequest("getSales", httpReq, serviceResults);
		httpRes.json(serviceResults); //dispatch results to browser immediately 
		httpReq.completed = true;
	}
}