From f3e545057da1689eca68df3726c5b9f8ee5bd6da Mon Sep 17 00:00:00 2001
From: Namekuji <nmkj@waah.day>
Date: Fri, 4 Aug 2023 01:21:56 -0400
Subject: [PATCH] refactor: reduce one redis flight

---
 packages/backend/src/misc/cache.ts | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/packages/backend/src/misc/cache.ts b/packages/backend/src/misc/cache.ts
index 2f979a78bf..26301939ef 100644
--- a/packages/backend/src/misc/cache.ts
+++ b/packages/backend/src/misc/cache.ts
@@ -148,12 +148,13 @@ class SetCache {
 	protected async fetch() {
 		// Sync from DB if nothing is cached yet or cache is expired
 		const ttlKey = `${this.key}:fetched`;
-		const fetched = await redisClient.exists(ttlKey);
-
-		if (!(await this.hasFollowing()) || fetched === 0) {
+		if (
+			!(await this.hasFollowing()) ||
+			(await redisClient.exists(ttlKey)) === 0
+		) {
 			await redisClient.del(this.key);
 			await this.follow(...(await this.fetcher()));
-			await redisClient.set(ttlKey, "yes", "EX", 60 * 30);
+			await redisClient.set(ttlKey, "yes", "EX", 60 * 30); // Expires in 30 minutes
 		}
 	}