nodejs redis 发布订阅机制封装实现方法及实例代码

var config = require('../config/config');var log = require("./loghelp");var redis = require("redis");function initialclient(param) {  var option={ host: config.redis.host, port: config.redis.port};  if(param)  {    option=Object.assign(option,param);  }  redis.print  let client = redis.createClient(option);  client.on("error", function(err) {    log.error(err);  });  return client;}

/*example:* let channel="ryan"; redis.pubSub.registerHandlers("ryan",msg=> console.log(msg)); redis.pubSub.subscribe(channel); redis.pubSub.publish(channel,"hello from chen");*/class PubSub{  constructor(){    this.sub=initialclient();    this.handlers=new Map();    this.subAction=(channle,message)=>{      let actions= this.handlers.get(channle)||new Set();      for(let action of actions)      {        action(message);      }    }    this.alredyPublishs=[];    this.subConnected=false;  }  publish(channel,message)  {    let action=()=>{      let pub=initialclient();      pub.publish(channel,message);    };    if(this.subConnected===false)    {      this.alredyPublishs.push(action);    }    else      action();  }  registerHandlers(channel,action)  {    var actions=this.handlers.get(channel)||new Set();    actions.add(action);    this.handlers.set(channel,actions);  }  subscribe(channel)  {    let self=this;    this.sub.subscribe(channel,function (err,reply) {      if(err)        log.error(err);      self.subConnected=true;      for(let publish of self.alredyPublishs)        publish();      console.log(reply);    });    this.sub.on("message", function (channel, message) {      self.subAction(channel,message);    });  }  tearDown()  {    this.sub.quit();  }}