Allow for background timers to be overriden (#556)

* Allow for background timers to be overriden for platform specific implementations

* Add changeset

* Formatting

* More timers converted and renamed to CriticalTimers

Author: davidliu

.changeset/weak-dogs-act.md

@@ -0,0 +1,5 @@
+---
+'livekit-client': patch
+---
+
+Allow for internal background timer implementation to be overridden

src/api/SignalClient.ts

@@ -31,6 +31,7 @@ import {
   UpdateTrackSettings,
 } from '../proto/livekit_rtc';
 import { ConnectionError, ConnectionErrorReason } from '../room/errors';
+import CriticalTimers from '../room/timers';
 import { getClientInfo, Mutex, sleep } from '../room/utils';
 
 // internal options
@@ -583,7 +584,7 @@ export class SignalClient {
       log.warn('ping timeout duration not set');
       return;
     }
-    this.pingTimeout = setTimeout(() => {
+    this.pingTimeout = CriticalTimers.setTimeout(() => {
       log.warn(
         `ping timeout triggered. last pong received at: ${new Date(
           Date.now() - this.pingTimeoutDuration! * 1000,
@@ -597,7 +598,7 @@ export class SignalClient {
 
   private clearPingTimeout() {
     if (this.pingTimeout) {
-      clearTimeout(this.pingTimeout);
+      CriticalTimers.clearTimeout(this.pingTimeout);
     }
   }
 
@@ -609,7 +610,7 @@ export class SignalClient {
       return;
     }
     log.debug('start ping interval');
-    this.pingInterval = setInterval(() => {
+    this.pingInterval = CriticalTimers.setInterval(() => {
       this.sendPing();
     }, this.pingIntervalDuration * 1000);
   }
@@ -618,7 +619,7 @@ export class SignalClient {
     log.debug('clearing ping interval');
     this.clearPingTimeout();
     if (this.pingInterval) {
-      clearInterval(this.pingInterval);
+      CriticalTimers.clearInterval(this.pingInterval);
     }
   }
 }

src/index.ts

@@ -16,6 +16,7 @@ import RemoteTrackPublication from './room/track/RemoteTrackPublication';
 import RemoteVideoTrack from './room/track/RemoteVideoTrack';
 import type { ElementInfo } from './room/track/RemoteVideoTrack';
 import { TrackPublication } from './room/track/TrackPublication';
+import CriticalTimers from './room/timers';
 import {
   getEmptyAudioStreamTrack,
   getEmptyVideoStreamTrack,
@@ -71,4 +72,5 @@ export {
   ConnectionQuality,
   ElementInfo,
   DefaultReconnectPolicy,
+  CriticalTimers,
 };

src/room/RTCEngine.ts

@@ -32,6 +32,7 @@ import {
 import { EngineEvent } from './events';
 import PCTransport, { PCEvents } from './PCTransport';
 import type { ReconnectContext, ReconnectPolicy } from './ReconnectPolicy';
+import CriticalTimers from './timers';
 import type LocalTrack from './track/LocalTrack';
 import type LocalVideoTrack from './track/LocalVideoTrack';
 import type { SimulcastTrackInfo } from './track/LocalVideoTrack';
@@ -710,10 +711,11 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
 
     log.debug(`reconnecting in ${delay}ms`);
 
-    if (this.reconnectTimeout) {
-      clearTimeout(this.reconnectTimeout);
-    }
-    this.reconnectTimeout = setTimeout(() => this.attemptReconnect(signalEvents), delay);
+    this.clearReconnectTimeout();
+    this.reconnectTimeout = CriticalTimers.setTimeout(
+      () => this.attemptReconnect(signalEvents),
+      delay,
+    );
   };
 
   private async attemptReconnect(signalEvents: boolean = false) {
@@ -740,11 +742,8 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
       } else {
         await this.resumeConnection(signalEvents);
       }
-      this.reconnectAttempts = 0;
+      this.clearPendingReconnect();
       this.fullReconnectOnNext = false;
-      if (this.reconnectTimeout) {
-        clearTimeout(this.reconnectTimeout);
-      }
     } catch (e) {
       this.reconnectAttempts += 1;
       let reconnectRequired = false;
@@ -1046,19 +1045,21 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
     }
   }
 
-  private clearPendingReconnect() {
+  private clearReconnectTimeout() {
     if (this.reconnectTimeout) {
-      clearTimeout(this.reconnectTimeout);
+      CriticalTimers.clearTimeout(this.reconnectTimeout);
     }
+  }
+
+  private clearPendingReconnect() {
+    this.clearReconnectTimeout();
     this.reconnectAttempts = 0;
   }
 
   private handleBrowserOnLine = () => {
     // in case the engine is currently reconnecting, attempt a reconnect immediately after the browser state has changed to 'onLine'
     if (this.client.isReconnecting) {
-      if (this.reconnectTimeout) {
-        clearTimeout(this.reconnectTimeout);
-      }
+      this.clearReconnectTimeout();
       this.attemptReconnect(true);
     }
   };

src/room/Room.ts

@@ -44,6 +44,7 @@ import type Participant from './participant/Participant';
 import type { ConnectionQuality } from './participant/Participant';
 import RemoteParticipant from './participant/RemoteParticipant';
 import RTCEngine from './RTCEngine';
+import CriticalTimers from './timers';
 import LocalAudioTrack from './track/LocalAudioTrack';
 import LocalTrackPublication from './track/LocalTrackPublication';
 import LocalVideoTrack from './track/LocalVideoTrack';
@@ -364,15 +365,15 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
       }
 
       // don't return until ICE connected
-      const connectTimeout = setTimeout(() => {
+      const connectTimeout = CriticalTimers.setTimeout(() => {
         // timeout
         this.recreateEngine();
         this.handleDisconnect(this.options.stopLocalTrackOnUnpublish);
         reject(new ConnectionError('could not connect PeerConnection after timeout'));
       }, this.connOptions.peerConnectionTimeout);
       const abortHandler = () => {
         log.warn('closing engine');
-        clearTimeout(connectTimeout);
+        CriticalTimers.clearTimeout(connectTimeout);
         this.recreateEngine();
         this.handleDisconnect(this.options.stopLocalTrackOnUnpublish);
         reject(new ConnectionError('room connection has been cancelled'));
@@ -383,7 +384,7 @@ class Room extends (EventEmitter as new () => TypedEmitter<RoomEventCallbacks>)
       this.abortController?.signal.addEventListener('abort', abortHandler);
 
       this.engine.once(EngineEvent.Connected, () => {
-        clearTimeout(connectTimeout);
+        CriticalTimers.clearTimeout(connectTimeout);
         this.abortController?.signal.removeEventListener('abort', abortHandler);
         // also hook unload event
         if (isWeb()) {

src/room/timers.ts

@@ -0,0 +1,14 @@
+/**
+ * Timers that can be overridden with platform specific implementations
+ * that ensure that they are fired. These should be used when it is critical
+ * that the timer fires on time.
+ */
+export default class CriticalTimers {
+  static setTimeout = setTimeout;
+
+  static setInterval = setInterval;
+
+  static clearTimeout = clearTimeout;
+
+  static clearInterval = clearInterval;
+}

src/room/track/RemoteVideoTrack.ts

@@ -2,6 +2,7 @@ import { debounce } from 'ts-debounce';
 import log from '../../logger';
 import { TrackEvent } from '../events';
 import { computeBitrate, VideoReceiverStats } from '../stats';
+import CriticalTimers from '../timers';
 import { getIntersectionObserver, getResizeObserver, ObservableMediaElement } from '../utils';
 import RemoteTrack from './RemoteTrack';
 import { attachToElement, detachTrack, Track } from './Track';
@@ -233,7 +234,7 @@ export default class RemoteVideoTrack extends RemoteTrack {
 
     if (!isVisible && Date.now() - lastVisibilityChange < REACTION_DELAY) {
       // delay hidden events
-      setTimeout(() => {
+      CriticalTimers.setTimeout(() => {
         this.updateVisibility();
       }, REACTION_DELAY);
       return;