加速vue组件渲染之性能优化

export default {
  data(){
    return {
      tableTitle:[
        {
          label:'省份',
          prop:'prop'
        },
        {
          label:'城市',
          prop:'prop'
        },
        {
          label:'汇总',
          prop:'prop',
          colconfig:[
            {
              label:'下级',
              prop:'prop'
            }
          ]
        }
        ...
      ]
    }
  }
}

function defineReactive(obj,key,val) {
 var dep = new Dep();
 var property = Object.getOwnPropertyDescriptor(obj, key);
 //如果对象被冻结，则直接跳出，不重写 get set方法
 if (property && property.configurable === false) {
  return
 }
 //observe会递归调用defineReactive，去重写对象内层的get set属性
 var childOb = !shallow && observe(val);
 Object.defineProperty(obj, key, {
  enumerable: true,
  configurable: true,
  get: function reactiveGetter () {
  },
  set: function reactiveSetter (newVal) {
  }
 });
}

export default {

data(){
  return {
    tableTitle:Object.freeze(objConfig)
  }
}
}

export default {
  created(){
    this.tableTitle = [xxxxx]
  }
}