text: /*
   * Handle CRUD opeartion in redis.
   * Author: Minchuian Gao<mqgao@outlook.com>
   * Date: 2015-Oct-21
   */
  
  
  function RedisHandler(){
  	var redis = require('redis');
  
  	var client = redis.createClient();
  	this.user_id = 0;
  
  	this.create_a_user = function(user){
  		this.client.hset(user.user_name, user);
  	};
  
  	this.give_a_user = function(user_name){
  		// return a user's information by its name.
  		if(this.client.hexists(user_name)){
  			return this.client.hget(user.user_name);
  		}else{
  			return false;
  		}
  	};
  
  	this.delete_a_user = function(user_name){
  		return this.client.hdel(user_name);
  	};
  	*/
  }
  
  user = {'user_name':'Gao', 'age':22};
  
  redisHandler = RedisHandler();
  /*
  redisHandler.create_a_user(user);
  console.info(redisHandler. give_a_user('Gao'));
  redisHandler.delete_a_user('Gao');
  console.info(redisHandler. give_a_user('Gao'));
  */
  