Move redis code to middleware

src/middleware/queryCacher.ts

@@ -0,0 +1,35 @@
+import redis from "../utils/redis";
+import { Logger } from "../utils/logger";
+import { skipSegmentsHashKey, skipSegmentsKey } from "./redisKeys";
+import { Service, VideoID, VideoIDHash } from "../types/segments.model";
+
+async function get<T>(fetchFromDB: () => Promise<T[]>, key: string): Promise<T[]> {
+    const {err, reply} = await redis.getAsync(key);
+
+    if (!err && reply) {
+        try {
+            Logger.debug("Got data from redis: " + reply);
+            return JSON.parse(reply);
+        } catch (e) {
+            // If all else, continue on to fetching from the database
+        }
+    }
+
+    const data = await fetchFromDB();
+
+    redis.setAsync(key, JSON.stringify(data));
+    return data;
+}
+
+function clearVideoCache(videoInfo: { videoID: VideoID; hashedVideoID: VideoIDHash; service: Service; }) {
+    if (videoInfo) {
+        redis.delAsync(skipSegmentsKey(videoInfo.videoID, videoInfo.service));
+        redis.delAsync(skipSegmentsHashKey(videoInfo.hashedVideoID, videoInfo.service));
+    }
+}
+
+
+export const QueryCacher = {
+    get,
+    clearVideoCache
+}