organize dirs

2021-12-21 17:57:18 +07:00
parent 249525ee90
commit 1ed757aca0
32 changed files with 128 additions and 122 deletions
@@ -0,0 +1,162 @@
+import 'dart:async';
+
+import 'package:flutter_webrtc/flutter_webrtc.dart' as rtc;
+
+import '../constants.dart';
+import '../extensions.dart';
+import '../logger.dart';
+import '../support/disposable.dart';
+import '../types.dart';
+import '../utils.dart';
+
+typedef PCTransportOnOffer = void Function(rtc.RTCSessionDescription offer);
+
+/// a wrapper around PeerConnection
+class PCTransport extends Disposable {
+  final rtc.RTCPeerConnection pc;
+  final List<rtc.RTCIceCandidate> _pendingCandidates = [];
+  bool restartingIce = false;
+  bool renegotiate = false;
+  PCTransportOnOffer? onOffer;
+  Function? _cancelDebounce;
+
+  // private constructor
+  PCTransport._(this.pc) {
+    //
+    onDispose(() async {
+      _cancelDebounce?.call();
+      _cancelDebounce = null;
+
+      // Ensure callbacks won't fire any more
+      pc.onRenegotiationNeeded = null;
+      pc.onIceCandidate = null;
+      pc.onIceConnectionState = null;
+      pc.onTrack = null;
+
+      // Remove all senders
+      List<rtc.RTCRtpSender> senders = [];
+      try {
+        senders = await pc.getSenders();
+      } catch (_) {
+        logger.warning('getSenders() failed with error: $_');
+      }
+
+      for (final e in senders) {
+        try {
+          await pc.removeTrack(e);
+        } catch (_) {
+          logger.warning('removeTrack() failed with error: $_');
+        }
+      }
+
+      await pc.close();
+      await pc.dispose();
+    });
+  }
+
+  static Future<PCTransport> create([RTCConfiguration? rtcConfig]) async {
+    rtcConfig ??= const RTCConfiguration();
+    logger.fine('[PCTransport] creating ${rtcConfig.toMap()}');
+    final _ = await rtc.createPeerConnection(rtcConfig.toMap());
+    return PCTransport._(_);
+  }
+
+  late final negotiate = Utils.createDebounceFunc(
+    (void _) => createAndSendOffer(),
+    cancelFunc: (f) => _cancelDebounce = f,
+    wait: Timeouts.debounce,
+  );
+
+  Future<void> setRemoteDescription(rtc.RTCSessionDescription sd) async {
+    if (isDisposed) {
+      logger.warning('[$objectId] setRemoteDescription() already disposed');
+      return;
+    }
+
+    await pc.setRemoteDescription(sd);
+
+    for (final candidate in _pendingCandidates) {
+      await pc.addCandidate(candidate);
+    }
+
+    _pendingCandidates.clear();
+    restartingIce = false;
+
+    if (renegotiate) {
+      renegotiate = false;
+      await createAndSendOffer(); // await or un-awaited ?
+    }
+  }
+
+  Future<void> createAndSendOffer([RTCOfferOptions? options]) async {
+    if (isDisposed) {
+      logger.warning('[$objectId] createAndSendOffer() already disposed');
+      return;
+    }
+
+    if (onOffer == null) {
+      logger.warning('onOffer is null');
+      return;
+    }
+
+    if (options?.iceRestart ?? false) {
+      logger.fine('restarting ICE');
+      restartingIce = true;
+    }
+
+    if (pc.signalingState ==
+        rtc.RTCSignalingState.RTCSignalingStateHaveLocalOffer) {
+      // we're waiting for the peer to accept our offer, so we'll just wait
+      // the only exception to this is when ICE restart is needed
+      final currentSD = await getRemoteDescription();
+      if ((options?.iceRestart ?? false) && currentSD != null) {
+        // TODO: handle when ICE restart is needed but we don't have a remote description
+        // the best thing to do is to recreate the peerconnection
+        await pc.setRemoteDescription(currentSD);
+      } else {
+        renegotiate = true;
+        return;
+      }
+    }
+
+    // actually negotiate
+    logger.fine('starting to negotiate');
+    final offer = await pc.createOffer(options?.toMap() ?? <String, dynamic>{});
+    await pc.setLocalDescription(offer);
+    onOffer?.call(offer);
+  }
+
+  Future<void> addIceCandidate(rtc.RTCIceCandidate candidate) async {
+    if (isDisposed) {
+      logger.warning('[$objectId] addIceCandidate() already disposed');
+      return;
+    }
+
+    final desc = await getRemoteDescription();
+
+    if (desc != null && !restartingIce) {
+      await pc.addCandidate(candidate);
+      return;
+    }
+
+    _pendingCandidates.add(candidate);
+  }
+
+  Future<rtc.RTCSessionDescription?> getRemoteDescription() async {
+    if (isDisposed) {
+      logger.warning('[$objectId] getRemoteDescription() already disposed');
+      return null;
+    }
+
+    // Checking agains null doesn't work as intended
+    // if (pc.iceConnectionState == null) return null;
+
+    try {
+      final result = await pc.getRemoteDescription();
+      logger.fine('pc.getRemoteDescription $result');
+      return result;
+    } catch (_) {
+      logger.warning('pc.getRemoteDescription failed with error: $_');
+    }
+  }
+}