From 4767c28ae43545eabb88ab417349c9c8b8ee81e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Espino=20Garc=C3=ADa?= <larkox@gmail.com>
Date: Mon, 7 Aug 2023 09:43:46 +0200
Subject: [PATCH] Avoid unneeded group fetches (#7482)

---
 app/actions/remote/user.ts | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/app/actions/remote/user.ts b/app/actions/remote/user.ts
index 5c0facba2..f6297db66 100644
--- a/app/actions/remote/user.ts
+++ b/app/actions/remote/user.ts
@@ -294,14 +294,19 @@ const debouncedFetchUserOrGroupsByMentionNames = debounce(
     },
 );
 
+const notFoundMentions: {[serverUrl: string]: Set<string>} = {};
 const fetchUserOrGroupsByMentionNames = async (serverUrl: string, mentions: string[]) => {
     try {
+        if (!notFoundMentions[serverUrl]) {
+            notFoundMentions[serverUrl] = new Set();
+        }
+
         const {database} = DatabaseManager.getServerDatabaseAndOperator(serverUrl);
 
         // Get any missing users
         const usersInDb = await queryUsersByIdsOrUsernames(database, [], mentions).fetch();
         const usersMap = new Set(usersInDb.map((u) => u.username));
-        const usernamesToFetch = mentions.filter((m) => !usersMap.has(m));
+        const usernamesToFetch = mentions.filter((m) => !usersMap.has(m) && !notFoundMentions[serverUrl].has(m));
 
         let fetchedUsers;
         if (usernamesToFetch.length) {
@@ -317,7 +322,15 @@ const fetchUserOrGroupsByMentionNames = async (serverUrl: string, mentions: stri
         const groupsToFetch = groupsToCheck.filter((g) => !groupsMap.has(g));
 
         if (groupsToFetch.length) {
-            await fetchGroupsByNames(serverUrl, groupsToFetch, false);
+            const results = await fetchGroupsByNames(serverUrl, groupsToFetch, false);
+            if (!('error' in results)) {
+                const retrievedSet = new Set(results.map((r) => r.name));
+                for (const g of groupsToFetch) {
+                    if (!retrievedSet.has(g)) {
+                        notFoundMentions[serverUrl].add(g);
+                    }
+                }
+            }
         }
         return {};
     } catch (error) {