From b5c879ae853225c7d00407ea44e22780a862ac2e Mon Sep 17 00:00:00 2001
From: Florian Duros <florian.duros@ormaz.fr>
Date: Fri, 27 Feb 2026 14:40:30 +0100
Subject: [PATCH] perf(room list): avoid to create new filter ids and keys when
 the room list is updated

The filterKeys are passed in the virtuoso context so it should reduce
internal computing

The filter ids array has always the same value, there is no point to
create a new instance.
---
 .../src/viewmodels/room-list/RoomListViewViewModel.ts    | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/apps/web/src/viewmodels/room-list/RoomListViewViewModel.ts b/apps/web/src/viewmodels/room-list/RoomListViewViewModel.ts
index 093deba491..ed1c305796 100644
--- a/apps/web/src/viewmodels/room-list/RoomListViewViewModel.ts
+++ b/apps/web/src/viewmodels/room-list/RoomListViewViewModel.ts
@@ -25,6 +25,7 @@ import { RoomNotificationStateStore } from "../../stores/notifications/RoomNotif
 import { RoomListItemViewModel } from "./RoomListItemViewModel";
 import { SdkContextClass } from "../../contexts/SDKContext";
 import { hasCreateRoomRights } from "./utils";
+import { keepIfSame } from "../../utils/keepIfSame";
 
 interface RoomListViewViewModelProps {
     client: MatrixClient;
@@ -407,13 +408,16 @@ export class RoomListViewViewModel
         // Build the complete state atomically to ensure consistency
         // roomIds and roomListState must always be in sync
         const roomIds = this.roomIds;
+
+        // Update filter keys - only update if they have actually changed to prevent unnecessary re-renders of the room list
+        const previousFilterKeys = this.snapshot.current.roomListState.filterKeys;
+        const newFilterKeys = this.roomsResult.filterKeys?.map((k) => String(k));
         const roomListState: RoomListViewState = {
             activeRoomIndex,
             spaceId: this.roomsResult.spaceId,
-            filterKeys: this.roomsResult.filterKeys?.map((k) => String(k)),
+            filterKeys: keepIfSame(previousFilterKeys, newFilterKeys),
         };
 
-        const filterIds = [...filterKeyToIdMap.values()];
         const activeFilterId = this.activeFilter !== undefined ? filterKeyToIdMap.get(this.activeFilter) : undefined;
         const isRoomListEmpty = roomIds.length === 0;
         const isLoadingRooms = RoomListStoreV3.instance.isLoadingRooms;
@@ -422,7 +426,6 @@ export class RoomListViewViewModel
         this.snapshot.merge({
             isLoadingRooms,
             isRoomListEmpty,
-            filterIds,
             activeFilterId,
             roomListState,
             roomIds,