SOURCE

var synchronousFile = function(id){
			console.log('开始同步文件,id为:'+id)
		}

		var proxySynchronousFile =(function(){
			var cache = [],timer;

			return function(id){
				cache.push(id)
				if(timer){
					return
				}

				timer = setTimeout(function(){
					synchronousFile(cache.join(','))
					clearTimeout(timer)
					timer = null;
					cache.length = 0
				},2000)
			}
		})()

		var checkbox = document.getElementsByTagName('input');
		for(var i=0,c;c = checkbox[i++];){
			console.log(c)
			c.onclick = function(){
				// console.log(this.checked)
				if(this.checked === true){
					console.log(this.id)
					proxySynchronousFile(this.id);
				}
			}
		}