add util function throttle and debounce

@@ -131,6 +131,35 @@ const miniVersion = function (miniVersion) {
     return false;
 };
 
+const debounce = function(idle, action) { // 函数去抖动，超过一定时间才会执行，如果周期内触发，重置计时器
+    let last;
+
+    return function() {
+        let args = arguments;
+
+        if (last) {
+            clearTimeout(last);
+        }
+        last = setTimeout(() => {
+            action.apply(this, args);
+        }, idle);
+    };
+};
+
+const throttle = function(delay, action) { // 函数节流器，定义函数执行间隔，按频率触发函数
+    let last = 0;
+
+    return function() {
+        let args = arguments;
+        let curr = +new Date();
+
+        if (curr - last > delay) {
+            action.apply(this, args);
+            last = curr;
+        }
+    };
+};
+
 export default {
     getImgHost,
     getImgUrl,
@@ -138,5 +167,7 @@ export default {
     visibilitychange,
     getChannel,
     replaceHttp,
-    miniVersion
+    miniVersion,
+    debounce,
+    throttle
 };