Room List Store: Filter rooms by active space (#29399)

* Add method to await space store setup

Otherwise, the room list store will get incorrect information about
spaces and thus will produce an incorrect roomlist.

* Implement a way to filter by active space

Implement a way to filter by active space

* Fix broken jest tests

* Fix typo

* Rename `isReady` to `storeReadyPromise`

* Fix mock in test

src/stores/room-list-v3/RoomListStoreV3.ts

@@ -21,6 +21,8 @@ import { RecencySorter } from "./skip-list/sorters/RecencySorter";
 import { AlphabeticSorter } from "./skip-list/sorters/AlphabeticSorter";
 import { readReceiptChangeIsFor } from "../../utils/read-receipts";
 import { EffectiveMembership, getEffectiveMembership, getEffectiveMembershipTag } from "../../utils/membership";
+import SpaceStore from "../spaces/SpaceStore";
+import { UPDATE_HOME_BEHAVIOUR, UPDATE_SELECTED_SPACE } from "../spaces";
 
 /**
  * This store allows for fast retrieval of the room list in a sorted and filtered manner.
@@ -34,6 +36,10 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
     public constructor(dispatcher: MatrixDispatcher) {
         super(dispatcher);
         this.msc3946ProcessDynamicPredecessor = SettingsStore.getValue("feature_dynamic_room_predecessors");
+        SpaceStore.instance.on(UPDATE_SELECTED_SPACE, () => {
+            this.onActiveSpaceChanged();
+        });
+        SpaceStore.instance.on(UPDATE_HOME_BEHAVIOUR, () => this.onActiveSpaceChanged());
     }
 
     /**
@@ -53,6 +59,14 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
         else return [];
     }
 
+    /**
+     * Get a list of sorted rooms that belong to the currently active space.
+     */
+    public getSortedRoomsInActiveSpace(): Room[] {
+        if (this.roomSkipList?.initialized) return Array.from(this.roomSkipList.getRoomsInActiveSpace());
+        else return [];
+    }
+
     /**
      * Re-sort the list of rooms by alphabetic order.
      */
@@ -78,6 +92,7 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
         const sorter = new RecencySorter(this.matrixClient.getSafeUserId());
         this.roomSkipList = new RoomSkipList(sorter);
         const rooms = this.getRooms();
+        await SpaceStore.instance.storeReadyPromise;
         this.roomSkipList.seed(rooms);
         this.emit(LISTS_UPDATE_EVENT);
     }
@@ -178,6 +193,12 @@ export class RoomListStoreV3Class extends AsyncStoreWithClient<EmptyObject> {
         this.roomSkipList.addRoom(room);
         this.emit(LISTS_UPDATE_EVENT);
     }
+
+    private onActiveSpaceChanged(): void {
+        if (!this.roomSkipList) return;
+        this.roomSkipList.calculateActiveSpaceForNodes();
+        this.emit(LISTS_UPDATE_EVENT);
+    }
 }
 
 export default class RoomListStoreV3 {

src/stores/room-list-v3/skip-list/RoomNode.ts

@@ -6,6 +6,7 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import type { Room } from "matrix-js-sdk/src/matrix";
+import SpaceStore from "../../spaces/SpaceStore";
 
 /**
  * Room skip list stores room nodes.
@@ -13,6 +14,8 @@ import type { Room } from "matrix-js-sdk/src/matrix";
  * in different levels.
  */
 export class RoomNode {
+    private _isInActiveSpace: boolean = false;
+
     public constructor(public readonly room: Room) {}
 
     /**
@@ -26,4 +29,23 @@ export class RoomNode {
      * eg: previous[i] gives the previous room node from this room node in level i.
      */
     public previous: RoomNode[] = [];
+
+    /**
+     * Whether the room associated with this room node belongs to
+     * the currently active space.
+     * @see {@link SpaceStoreClass#activeSpace} to understand what active
+     * space means.
+     */
+    public get isInActiveSpace(): boolean {
+        return this._isInActiveSpace;
+    }
+
+    /**
+     * Check if this room belongs to the active space and store the result
+     * in {@link RoomNode#isInActiveSpace}.
+     */
+    public checkIfRoomBelongsToActiveSpace(): void {
+        const activeSpace = SpaceStore.instance.activeSpace;
+        this._isInActiveSpace = SpaceStore.instance.isRoomInSpace(activeSpace, this.room.roomId);
+    }
 }

src/stores/room-list-v3/skip-list/RoomSkipList.ts

@@ -44,9 +44,22 @@ export class RoomSkipList implements Iterable<Room> {
             this.levels[currentLevel.level] = currentLevel;
             currentLevel = currentLevel.generateNextLevel();
         } while (currentLevel.size > 1);
+
+        // 3. Go through the list of rooms and mark nodes in active space
+        this.calculateActiveSpaceForNodes();
+
         this.initialized = true;
     }
 
+    /**
+     * Go through all the room nodes and check if they belong to the active space.
+     */
+    public calculateActiveSpaceForNodes(): void {
+        for (const node of this.roomNodeMap.values()) {
+            node.checkIfRoomBelongsToActiveSpace();
+        }
+    }
+
     /**
      * Change the sorting algorithm used by the skip list.
      * This will reset the list and will rebuild from scratch.
@@ -81,6 +94,7 @@ export class RoomSkipList implements Iterable<Room> {
         this.removeRoom(room);
 
         const newNode = new RoomNode(room);
+        newNode.checkIfRoomBelongsToActiveSpace();
         this.roomNodeMap.set(room.roomId, newNode);
 
         /**
@@ -159,6 +173,10 @@ export class RoomSkipList implements Iterable<Room> {
         return new SortedRoomIterator(this.levels[0].head!);
     }
 
+    public getRoomsInActiveSpace(): SortedSpaceFilteredIterator {
+        return new SortedSpaceFilteredIterator(this.levels[0].head!);
+    }
+
     /**
      * The number of rooms currently in the skip list.
      */
@@ -179,3 +197,23 @@ class SortedRoomIterator implements Iterator<Room> {
         };
     }
 }
+
+class SortedSpaceFilteredIterator implements Iterator<Room> {
+    public constructor(private current: RoomNode) {}
+
+    public [Symbol.iterator](): SortedSpaceFilteredIterator {
+        return this;
+    }
+
+    public next(): IteratorResult<Room> {
+        let current = this.current;
+        while (current && !current.isInActiveSpace) {
+            current = current.next[0];
+        }
+        if (!current) return { value: undefined, done: true };
+        this.current = current.next[0];
+        return {
+            value: current.room,
+        };
+    }
+}

src/stores/spaces/SpaceStore.ts

@@ -21,6 +21,7 @@ import {
 } from "matrix-js-sdk/src/matrix";
 import { KnownMembership } from "matrix-js-sdk/src/types";
 import { logger } from "matrix-js-sdk/src/logger";
+import { defer } from "matrix-js-sdk/src/utils";
 
 import { AsyncStoreWithClient } from "../AsyncStoreWithClient";
 import defaultDispatcher from "../../dispatcher/dispatcher";
@@ -152,6 +153,7 @@ export class SpaceStoreClass extends AsyncStoreWithClient<EmptyObject> {
     private _enabledMetaSpaces: MetaSpace[] = [];
     /** Whether the feature flag is set for MSC3946 */
     private _msc3946ProcessDynamicPredecessor: boolean = SettingsStore.getValue("feature_dynamic_room_predecessors");
+    private _storeReadyDeferred = defer();
 
     public constructor() {
         super(defaultDispatcher, {});
@@ -162,6 +164,14 @@ export class SpaceStoreClass extends AsyncStoreWithClient<EmptyObject> {
         SettingsStore.monitorSetting("feature_dynamic_room_predecessors", null);
     }
 
+    /**
+     * A promise that resolves when the space store is ready.
+     * This happens after an initial hierarchy of spaces and rooms has been computed.
+     */
+    public get storeReadyPromise(): Promise<void> {
+        return this._storeReadyDeferred.promise;
+    }
+
     /**
      * Get the order of meta spaces to display in the space panel.
      *
@@ -1201,6 +1211,7 @@ export class SpaceStoreClass extends AsyncStoreWithClient<EmptyObject> {
         } else {
             this.switchSpaceIfNeeded();
         }
+        this._storeReadyDeferred.resolve();
     }
 
     private sendUserProperties(): void {