Node.js阻止事件循环

我正在编写一个API，并且我陷入了根据传入请求混合异步和同步代码的困境，请看下面的示例。

路由.js

module.exports = [
    {
        method: 'GET',
        path: '/',
        controller: 'main',
        action: 'main',
        description: 'lists the API functionality',
        access: 'auth'
    },
    {
        method: 'POST',
        path: '/users',
        controller: 'users',
        action: 'create',
        description: 'creates a new user',
        fields: {
            fullName: {
                format: {
                    min: 2,
                    max: 64,
                    minWords: 2,
                    disableDoubleSpaces: true
                },
                description: 'the full name of the new user',
                examples: 'Thomas Richards, Richard Jones, Michael J. Fox, Mike Vercoelen, John Johnson'
            },
            email: {
                format: {
                    min: 2,
                    max: 64,
                    maxWords: 1,
                    match: 'email'
                },
                description: 'the email address of the new user',
                examples: 'mike@grubt.com, lilly@gmail.com, thomas.richards@mail.com, peter@mymail.com'
            },
            password: {
                format: {
                    min: 2,
                    max: 64
                },
                description: 'the password of the new user',
                examples: '123abcdfg, 7373kEjQjd, #8klKDNfk'
            }
        }
    }
];

routes.js文件基本上是API的一个非常重要的部分，它验证传入数据，路由到正确的控制器/操作，并定义该方法是公共的，还是需要身份验证（基本身份验证）。

api server.js

var http = require('http');
var url = require('url');
var os = require('os');
var dns = require('dns');
var apiServer = module.exports;
var routes = require('./routes.js'); // Routes file from above.
var req, res, controller, action, serverInfo, httpServer;
apiServer.start = function(){
  prepare(function(){
    httpServer = http.createServer(handleRequest).listen(3000);
  });
};
//
// We need to do this function, we need the local ip address of the 
// server. We use this local ip address in logs (mongoDb) so we can
// refer to the correct server.
//
function prepare(callback){
  var serverName = os.hostname();
  dns.lookup(serverName, function(error, address){
    if(error){
      throw error;
    }
    serverInfo = {
      name: serverName,
      address: address
    };
    callback();
  });
}
function getRoute(){
  // loops through routes array, and picks the correct one...
}
function getAuth(callback){
  // parses headers, async authentication (mongoDB).
}
function getRequestData(callback){
  // req.on('data') and req.on('end'), getting request data.
}
function parseRequestData(callback){
  // parse request data at this point.
}
function validateRequestData(callback){
  // loop through route fields (see routes.js) and validate this data with the ones
  // from the request.
}
function requireControllerAndCallAction(){
  // do actual job.
}
function handleRequest(request, response){
  req = request;
  res = response;
  req.route = getRoute(); // First step for a request, syncronous.
  if(req.route === false){
    // 404...
  }
  // If in the routing schema access was "auth", 
  // this route requires authentication, so do that...
  if(req.route.access === 'auth'){
    getAuth(function(error, user){
      if(error){ // 401 } else {
        req.user = user;
      }
    }
  }
  if(req.method === 'POST' || req.method === 'PUT'){
    // Async functions.
    getRequestData(function(){
      parseRequestData(function(){
        validateRequestData(function(){
          requireControllerAndCallAction();
        });
      });
    });
  } else {
    requireControllerAndCallAction();
  }
}

正如您所看到的，有些函数是异步的（getAuth、getRequestData），有些是同步的（parseRequestData、validateRequestData）。

现在是这样的：

请求1。附带POST方法、url"/users"和数据：

• fullName='Rick'
• 电子邮件："rick@"
• 密码："a"

因此，我们循环通过API的工作流程：

1. 获取当前路由（控制器：用户，操作：创建）请参阅routes.js 中的第二个数组元素

2. 获取请求数据并在回调时：a.解析数据b.验证数据

现在让我们想象一下，数据的验证需要5秒（这是延迟的，但只是举个例子），在验证过程中，一个新的请求进来了，直到前一个请求完成，新的请求才被处理，对吗？