Add method to get member from storage

Signed-off-by: RMidhunSuresh <rmidhunsuresh@gmail.com>

src/matrix/room/BaseRoom.js

@@ -21,7 +21,7 @@ import {RelationWriter} from "./timeline/persistence/RelationWriter.js";
 import {Timeline} from "./timeline/Timeline.js";
 import {FragmentIdComparer} from "./timeline/FragmentIdComparer.js";
 import {WrappedError} from "../error.js"
-import {fetchOrLoadMembers} from "./members/load.js";
+import {fetchOrLoadMembers, loadMember} from "./members/load.js";
 import {MemberList} from "./members/MemberList.js";
 import {Heroes} from "./members/Heroes.js";
 import {EventEntry} from "./timeline/entries/EventEntry.js";
@@ -54,6 +54,7 @@ export class BaseRoom extends EventEmitter {
         this._observedEvents = null;
         this._powerLevels = null;
         this._powerLevelLoading = null;
+        this._observedMembers = null;
     }
 
     async _eventIdsToEntries(eventIds, txn) {
@@ -214,6 +215,23 @@ export class BaseRoom extends EventEmitter {
         }
     }
 
+    async observeMember(userId) {
+        if (!this._observedMembers) {
+            this._observedMembers = new Map();
+        }
+        const mapMember = this._observedMembers.get(userId);
+        if (mapMember) {
+            // Hit, we're already observing this member
+            return mapMember;
+        }
+        // Miss, load from storage and set in map
+        const member = await loadMember({roomId: this._roomId, userId, storage: this._storage});
+        const observableMember = new RetainedObservableValue(member, () => this._observedMembers.delete(userId));
+        this._observedMembers.set(userId, observableMember);
+        return observableMember;
+    }
+
+
     /** @public */
     async loadMemberList(log = null) {
         if (this._memberList) {

src/matrix/room/Room.js

@@ -209,6 +209,9 @@ export class Room extends BaseRoom {
             if (this._memberList) {
                 this._memberList.afterSync(memberChanges);
             }
+            if (this._observedMembers) {
+                this._updateObservedMembers(memberChanges);
+            }
             if (this._timeline) {
                 for (const [userId, memberChange] of memberChanges.entries()) {
                     if (userId === this._user.id) {
@@ -250,6 +253,15 @@ export class Room extends BaseRoom {
         }
     }
 
+    _updateObservedMembers(memberChanges) {
+        for (const [userId, memberChange] of memberChanges) {
+            const observableMember = this._observedMembers.get(userId);
+            if (observableMember) {
+                observableMember.set(memberChange.member);
+            }
+        }
+    }
+
     needsAfterSyncCompleted({shouldFlushKeyShares}) {
         return shouldFlushKeyShares;
     }

src/matrix/room/members/load.js

@@ -90,3 +90,9 @@ export async function fetchOrLoadMembers(options, logger) {
         return loadMembers(options);
     }
 }
+
+export async function loadMember({roomId, userId, storage}) {
+    const txn = await storage.readTxn([storage.storeNames.roomMembers,]);
+    const member = await txn.roomMembers.get(roomId, userId);
+    return new RoomMember(member);
+}