feat(core): caching enhancements (#9227)

* fix(core): redis cache ignore `maxAge` when refreshing

memory cache do not have such a problem

Signed-off-by: Rongrong <15956627+Rongronggg9@users.noreply.github.com>

* feat(core): make `cache.tryGet()` refreshing selectable

Signed-off-by: Rongrong <15956627+Rongronggg9@users.noreply.github.com>

* docs: `ctx.cache.tryGet()` update

Signed-off-by: Rongrong <15956627+Rongronggg9@users.noreply.github.com>

lib/middleware/cache/index.js

@@ -55,8 +55,8 @@ module.exports = function (app) {
     const { get, set, status } = cacheModule;
     app.context.cache = {
         ...cacheModule,
-        tryGet: async (key, getValueFunc, maxAge = config.cache.contentExpire) => {
-            let v = await get(key);
+        tryGet: async (key, getValueFunc, maxAge = config.cache.contentExpire, refresh = true) => {
+            let v = await get(key, refresh);
             if (!v) {
                 v = await getValueFunc();
                 set(key, v, maxAge);

lib/middleware/cache/redis.js

@@ -18,12 +18,26 @@ redisClient.on('connect', () => {
     logger.info('Redis connected.');
 });
 
+const getCacheTtlKey = (key) => {
+    if (key.startsWith('cacheTtl:')) {
+        throw Error('"cacheTtl:" prefix is reserved for the internal usage, please change your cache key'); // blocking any attempt to get/set the cacheTtl
+    }
+    return `cacheTtl:${key}`;
+};
+
 module.exports = {
     get: async (key, refresh = true) => {
         if (key && status.available) {
-            let value = await redisClient.get(key);
+            const cacheTtlKey = getCacheTtlKey(key);
+            let [value, cacheTtl] = await redisClient.mget(key, cacheTtlKey);
             if (value && refresh) {
-                redisClient.expire(key, config.cache.contentExpire);
+                if (!cacheTtl) {
+                    cacheTtl = config.cache.contentExpire;
+                    redisClient.set(cacheTtlKey, cacheTtl, 'EX', cacheTtl);
+                } else {
+                    redisClient.expire(cacheTtlKey, cacheTtl);
+                }
+                redisClient.expire(key, cacheTtl);
                 value = value + '';
             }
             return value;
@@ -40,6 +54,7 @@ module.exports = {
             value = JSON.stringify(value);
         }
         if (key) {
+            redisClient.set(getCacheTtlKey(key), maxAge, 'EX', maxAge);
             return redisClient.set(key, value, 'EX', maxAge); // setMode: https://redis.io/commands/set
         }
     },