Add traces to branding endpoint

src/routes/getBranding.ts

@@ -19,7 +19,7 @@ enum BrandingSubmissionType {
     Thumbnail = "thumbnail"
 }
 
-export async function getVideoBranding(videoID: VideoID, service: Service, ip: IPAddress): Promise<BrandingResult> {
+export async function getVideoBranding(res: Response, videoID: VideoID, service: Service, ip: IPAddress): Promise<BrandingResult> {
     const getTitles = () => db.prepare(
         "all",
         `SELECT "titles"."title", "titles"."original", "titleVotes"."votes", "titleVotes"."locked", "titleVotes"."shadowHidden", "titles"."UUID", "titles"."videoID", "titles"."hashedVideoID"
@@ -43,7 +43,13 @@ export async function getVideoBranding(videoID: VideoID, service: Service, ip: I
         thumbnails: await getThumbnails()
     });
 
-    const branding = await QueryCacher.get(getBranding, brandingKey(videoID, service));
+    const brandingTrace = await QueryCacher.getTraced(getBranding, brandingKey(videoID, service));
+    const branding = brandingTrace.data;
+
+    // Add trace info to request for debugging purposes
+    res.setHeader("X-Start-Time", brandingTrace.startTime);
+    res.setHeader("X-DB-Start-Time", brandingTrace.dbStartTime);
+    res.setHeader("X-End-Time", brandingTrace.endTime);
 
     const cache = {
         currentIP: null as Promise<HashedIP> | null
@@ -177,7 +183,7 @@ export async function getBranding(req: Request, res: Response) {
 
     const ip = getIP(req);
     try {
-        const result = await getVideoBranding(videoID, service, ip);
+        const result = await getVideoBranding(res, videoID, service, ip);
 
         const status = result.titles.length > 0 || result.thumbnails.length > 0 ? 200 : 404;
         return res.status(status).json(result);

src/utils/queryCacher.ts

@@ -22,6 +22,41 @@ async function get<T>(fetchFromDB: () => Promise<T>, key: string): Promise<T> {
     return data;
 }
 
+
+async function getTraced<T>(fetchFromDB: () => Promise<T>, key: string): Promise<{
+    data: T;
+    startTime: number;
+    dbStartTime?: number;
+    endTime: number;
+}> {
+    const startTime = Date.now();
+
+    try {
+        const reply = await redis.get(key);
+        if (reply) {
+            Logger.debug(`Got data from redis: ${reply}`);
+
+            return {
+                data: JSON.parse(reply),
+                startTime: startTime,
+                endTime: Date.now()
+            };
+        }
+    } catch (e) { } //eslint-disable-line no-empty
+
+    const dbStartTime = Date.now();
+    const data = await fetchFromDB();
+
+    redis.setEx(key, config.redis?.expiryTime, JSON.stringify(data)).catch((err) => Logger.error(err));
+
+    return {
+        data,
+        startTime: startTime,
+        dbStartTime: dbStartTime,
+        endTime: Date.now()
+    };
+}
+
 /**
  * Gets from redis for all specified values and splits the result before adding it to redis cache
  */
@@ -117,6 +152,7 @@ function clearFeatureCache(userID: HashedUserID, feature: Feature): void {
 
 export const QueryCacher = {
     get,
+    getTraced,
     getAndSplit,
     clearSegmentCache,
     clearBrandingCache,