Implement broadcast UTD handling (#10021)

src/voice-broadcast/index.ts

@@ -52,6 +52,7 @@ export * from "./utils/doMaybeSetCurrentVoiceBroadcastPlayback";
 export * from "./utils/getChunkLength";
 export * from "./utils/getMaxBroadcastLength";
 export * from "./utils/hasRoomLiveVoiceBroadcast";
+export * from "./utils/isRelatedToVoiceBroadcast";
 export * from "./utils/isVoiceBroadcastStartedEvent";
 export * from "./utils/findRoomLiveVoiceBroadcastFromUserAndDevice";
 export * from "./utils/retrieveStartedInfoEvent";

src/voice-broadcast/models/VoiceBroadcastPlayback.ts

@@ -82,6 +82,8 @@ export class VoiceBroadcastPlayback
 {
     private state = VoiceBroadcastPlaybackState.Stopped;
     private chunkEvents = new VoiceBroadcastChunkEvents();
+    /** @var Map: event Id → undecryptable event */
+    private utdChunkEvents: Map<string, MatrixEvent> = new Map();
     private playbacks = new Map<string, Playback>();
     private currentlyPlaying: MatrixEvent | null = null;
     /** @var total duration of all chunks in milliseconds */
@@ -154,13 +156,18 @@ export class VoiceBroadcastPlayback
     }
 
     private addChunkEvent = async (event: MatrixEvent): Promise<boolean> => {
-        if (event.getContent()?.msgtype !== MsgType.Audio) {
-            // skip non-audio event
+        if (!event.getId() && !event.getTxnId()) {
+            // skip events without id and txn id
             return false;
         }
 
-        if (!event.getId() && !event.getTxnId()) {
-            // skip events without id and txn id
+        if (event.isDecryptionFailure()) {
+            this.onChunkEventDecryptionFailure(event);
+            return false;
+        }
+
+        if (event.getContent()?.msgtype !== MsgType.Audio) {
+            // skip non-audio event
             return false;
         }
 
@@ -174,6 +181,45 @@ export class VoiceBroadcastPlayback
         return true;
     };
 
+    private onChunkEventDecryptionFailure = (event: MatrixEvent): void => {
+        const eventId = event.getId();
+
+        if (!eventId) {
+            // This should not happen, as the existence of the Id is checked before the call.
+            // Log anyway and return.
+            logger.warn("Broadcast chunk decryption failure for event without Id", {
+                broadcast: this.infoEvent.getId(),
+            });
+            return;
+        }
+
+        if (!this.utdChunkEvents.has(eventId)) {
+            event.once(MatrixEventEvent.Decrypted, this.onChunkEventDecrypted);
+        }
+
+        this.utdChunkEvents.set(eventId, event);
+        this.setError();
+    };
+
+    private onChunkEventDecrypted = async (event: MatrixEvent): Promise<void> => {
+        const eventId = event.getId();
+
+        if (!eventId) {
+            // This should not happen, as the existence of the Id is checked before the call.
+            // Log anyway and return.
+            logger.warn("Broadcast chunk decrypted for event without Id", { broadcast: this.infoEvent.getId() });
+            return;
+        }
+
+        this.utdChunkEvents.delete(eventId);
+        await this.addChunkEvent(event);
+
+        if (this.utdChunkEvents.size === 0) {
+            // no more UTD events, recover from error to paused
+            this.setState(VoiceBroadcastPlaybackState.Paused);
+        }
+    };
+
     private startOrPlayNext = async (): Promise<void> => {
         if (this.currentlyPlaying) {
             return this.playNext();
@@ -210,7 +256,7 @@ export class VoiceBroadcastPlayback
     private async tryLoadPlayback(chunkEvent: MatrixEvent): Promise<void> {
         try {
             return await this.loadPlayback(chunkEvent);
-        } catch (err) {
+        } catch (err: any) {
             logger.warn("Unable to load broadcast playback", {
                 message: err.message,
                 broadcastId: this.infoEvent.getId(),
@@ -332,7 +378,7 @@ export class VoiceBroadcastPlayback
     private async tryGetOrLoadPlaybackForEvent(event: MatrixEvent): Promise<Playback | undefined> {
         try {
             return await this.getOrLoadPlaybackForEvent(event);
-        } catch (err) {
+        } catch (err: any) {
             logger.warn("Unable to load broadcast playback", {
                 message: err.message,
                 broadcastId: this.infoEvent.getId(),
@@ -551,9 +597,6 @@ export class VoiceBroadcastPlayback
     }
 
     private setState(state: VoiceBroadcastPlaybackState): void {
-        // error is a final state
-        if (this.getState() === VoiceBroadcastPlaybackState.Error) return;
-
         if (this.state === state) {
             return;
         }
@@ -587,10 +630,18 @@ export class VoiceBroadcastPlayback
     }
 
     public get errorMessage(): string {
-        return this.getState() === VoiceBroadcastPlaybackState.Error ? _t("Unable to play this voice broadcast") : "";
+        if (this.getState() !== VoiceBroadcastPlaybackState.Error) return "";
+        if (this.utdChunkEvents.size) return _t("Unable to decrypt voice broadcast");
+        return _t("Unable to play this voice broadcast");
     }
 
     public destroy(): void {
+        for (const [, utdEvent] of this.utdChunkEvents) {
+            utdEvent.off(MatrixEventEvent.Decrypted, this.onChunkEventDecrypted);
+        }
+
+        this.utdChunkEvents.clear();
+
         this.chunkRelationHelper.destroy();
         this.infoRelationHelper.destroy();
         this.removeAllListeners();

src/voice-broadcast/utils/isRelatedToVoiceBroadcast.ts

@@ -0,0 +1,29 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { MatrixClient, MatrixEvent, RelationType } from "matrix-js-sdk/src/matrix";
+
+import { VoiceBroadcastInfoEventType } from "../types";
+
+export const isRelatedToVoiceBroadcast = (event: MatrixEvent, client: MatrixClient): boolean => {
+    const relation = event.getRelation();
+
+    return (
+        relation?.rel_type === RelationType.Reference &&
+        !!relation.event_id &&
+        client.getRoom(event.getRoomId())?.findEventById(relation.event_id)?.getType() === VoiceBroadcastInfoEventType
+    );
+};