投注练习在Node js中初始化Pubnub

Question

我在节点js上使用pubnub。我注意到在我的套接字代码中我经常需要pubnub.js并在每次发送消息时传递pubsub密钥（在我的发布函数中）。我已经更新了代码，以便在我的模块中创建一个pubnub实例。但是，我想知道这是否是防弹和正确的方法。

(function(root, factory) {


  /* CommonJS */
  if (typeof exports == 'object')  module.exports = factory()

  /* AMD module */
  else if (typeof define == 'function' && define.amd) define(factory)

  /* Browser global */
  else root.Socket = factory();

}
(this, function() {

    //
    //
    // Is it ok to strike up a once only instance of pubnub here
    // in Node, or should i being doing it every time i call my publish 
    // function? The below should be the right way to do it> Require
    // pubnub when the node instance starts, get an instance and use it
    // forever more.
    //
    //
    var Pubnub = require("./pubnub"),
        pubnub = Pubnub({
            publish_key: "pub-c-xx",
            subscribe_key: "sub-c-xxx"
        });




    function publish(channel, data, cb){
      //
      // 
      // We use the instance above, BUT is this OK.
      //
      pubnub.publish({                                    
        channel : channel,
        message : data,
        callback : function(ev){
         if (cb) return cb(ev);
        }
      });
    }     




    var exports = {
        publish: publish,
    };

return exports;

}));