Improve performance of search all spaces and space switching

Author: t3chguy

src/stores/room-list/RoomListStore.ts

@@ -668,7 +668,7 @@ export class RoomListStoreClass extends AsyncStoreWithClient<IState> {
      * and thus might not cause an update to the store immediately.
      * @param {IFilterCondition} filter The filter condition to add.
      */
-    public addFilter(filter: IFilterCondition): void {
+    public async addFilter(filter: IFilterCondition): Promise<void> {
         if (SettingsStore.getValue("advancedRoomListLogging")) {
             // TODO: Remove debug: https://github.com/vector-im/element-web/issues/14602
             console.log("Adding filter condition:", filter);
@@ -680,12 +680,14 @@ export class RoomListStoreClass extends AsyncStoreWithClient<IState> {
             promise = this.recalculatePrefiltering();
         } else {
             this.filterConditions.push(filter);
-            if (this.algorithm) {
-                this.algorithm.addFilterCondition(filter);
-            }
             // Runtime filters with spaces disable prefiltering for the search all spaces effect
             if (SettingsStore.getValue("feature_spaces")) {
-                promise = this.recalculatePrefiltering();
+                // this has to be awaited so that `setKnownRooms` is called in time for the `addFilterCondition` below
+                // this way the runtime filters are only evaluated on one dataset and not both.
+                await this.recalculatePrefiltering();
+            }
+            if (this.algorithm) {
+                this.algorithm.addFilterCondition(filter);
             }
         }
         promise.then(() => this.updateFn.trigger());

src/stores/room-list/algorithms/Algorithm.ts

@@ -579,7 +579,6 @@ export class Algorithm extends EventEmitter {
 
         this.cachedRooms = newTags;
         this.updateTagsFromCache();
-        this.recalculateFilteredRooms();
 
         // Now that we've finished generation, we need to update the sticky room to what
         // it was. It's entirely possible that it changed lists though, so if it did then