Merge branch 'hotfix/add-cache' into gray

@@ -7,6 +7,43 @@
 const api = global.yoho.API;
 const config = global.yoho.config;
 const redis = global.yoho.redis;
+const cache = global.yoho.cache;
+const logger = global.yoho.logger;
+const uuid = require('uuid');
+
+function _cacheGet(key) {
+    return cache.get(key).then((data) => {
+        if (data) {
+            return JSON.parse(data);
+        }
+
+        return Promise.reject();
+    });
+}
+
+// 半个月
+const HALF_MONTH = 60 * 60 * 24 * 15;
+
+function _cacheSave(key, value) {
+    return cache.set(key, value, HALF_MONTH)
+        .catch(err => logger.error(`save cache data fail:${err.toString()}`));
+}
+
+function _cached(fn, ctx) {
+    const pre = 'recommend-cache:' + (fn.name || 'random:' + uuid.v4()) + ':';
+
+    return function() {
+        const args = Array.prototype.slice.call(arguments);
+        const key = pre + JSON.stringify(args || '[]');
+
+        return _cacheGet(key).catch(() => {
+            return fn.apply(ctx, args).then(result => {
+                _cacheSave(key, result);
+                return result;
+            });
+        });
+    };
+}
 
 /**
  * 商品的 banner
@@ -159,11 +196,11 @@ const getLikeAsync = (skn, limit) => {
 };
 
 // 根据small_sort从redis获取分类下的关键词
-const getRecommendKeywords = (smallSort) => {
+function _getRecommendKeywords(smallSort) {
     return redis.all([['get', `global:yoho:seo:keywords:sortId:${smallSort}:page:1`]]).then(res => {
         return res[0];
     });
-};
+}
 
 module.exports = {
     getProductBannerAsync,
@@ -177,5 +214,5 @@ module.exports = {
     getShopRecommendAsync,
     getBundleAsync,
     getLikeAsync,
-    getRecommendKeywords
+    getRecommendKeywords: _cached(_getRecommendKeywords)
 };