feat: add getBufferedAmount for DataChannel. (#1796)

* feat: add getBufferedAmount for DataChannel.

* update.

* update.

* fix.

* update binary for linux.

android/src/main/java/com/cloudwebrtc/webrtc/MethodCallHandlerImpl.java

@@ -482,6 +482,12 @@ public class MethodCallHandlerImpl implements MethodCallHandler, StateProvider {
         createDataChannel(peerConnectionId, label, new ConstraintsMap(dataChannelDict), result);
         break;
       }
+      case "dataChannelGetBufferedAmount": {
+        String peerConnectionId = call.argument("peerConnectionId");
+        String dataChannelId = call.argument("dataChannelId");
+        dataChannelGetBufferedAmount(peerConnectionId, dataChannelId, result);
+        break;
+      }
       case "dataChannelSend": {
         String peerConnectionId = call.argument("peerConnectionId");
         String dataChannelId = call.argument("dataChannelId");
@@ -2039,6 +2045,17 @@ public class MethodCallHandlerImpl implements MethodCallHandler, StateProvider {
     }
   }
 
+  public void dataChannelGetBufferedAmount(String peerConnectionId, String dataChannelId, Result result) {
+    PeerConnectionObserver pco
+            = mPeerConnectionObservers.get(peerConnectionId);
+    if (pco == null || pco.getPeerConnection() == null) {
+      Log.d(TAG, "dataChannelGetBufferedAmount() peerConnection is null");
+      resultError("dataChannelGetBufferedAmount", "peerConnection is null", result);
+    } else {
+      pco.dataChannelGetBufferedAmount(dataChannelId, result);
+    }
+  }
+
   public void dataChannelClose(String peerConnectionId, String dataChannelId) {
     // Forward to PeerConnectionObserver which deals with DataChannels
     // because DataChannel is owned by PeerConnection.

android/src/main/java/com/cloudwebrtc/webrtc/PeerConnectionObserver.java

@@ -168,6 +168,18 @@ class PeerConnectionObserver implements PeerConnection.Observer, EventChannel.St
     }
   }
 
+  void dataChannelGetBufferedAmount(String dataChannelId, Result result) {
+    DataChannel dataChannel = dataChannels.get(dataChannelId);
+    if (dataChannel != null) {
+      ConstraintsMap params = new ConstraintsMap();
+      params.putLong("bufferedAmount", dataChannel.bufferedAmount());
+      result.success(params.toMap());
+    } else {
+      Log.d(TAG, "dataChannelGetBufferedAmount() dataChannel is null");
+      resultError("dataChannelGetBufferedAmount", "DataChannel is null", result);
+    }
+  }
+
   RtpTransceiver getRtpTransceiverById(String id) {
     RtpTransceiver transceiver = transceivers.get(id);
     if (null == transceiver) {

common/cpp/include/flutter_data_channel.h

@@ -40,6 +40,9 @@ class FlutterDataChannel {
                        const EncodableValue& data,
                        std::unique_ptr<MethodResultProxy>);
 
+  void DataChannelGetBufferedAmount(RTCDataChannel* data_channel,
+                       std::unique_ptr<MethodResultProxy> result);
+
   void DataChannelClose(RTCDataChannel* data_channel,
                         const std::string& data_channel_uuid,
                         std::unique_ptr<MethodResultProxy>);

common/cpp/src/flutter_data_channel.cc

@@ -87,6 +87,13 @@ void FlutterDataChannel::DataChannelSend(
   result->Success();
 }
 
+void FlutterDataChannel::DataChannelGetBufferedAmount(RTCDataChannel* data_channel,
+                             std::unique_ptr<MethodResultProxy> result) {
+  EncodableMap params;
+  params[EncodableValue("bufferedAmount")] = EncodableValue((int64_t)data_channel->buffered_amount());
+  result->Success(EncodableValue(params));
+}
+
 void FlutterDataChannel::DataChannelClose(
     RTCDataChannel* data_channel,
     const std::string& data_channel_uuid,

common/cpp/src/flutter_webrtc.cc

@@ -352,6 +352,29 @@ void FlutterWebRTC::HandleMethodCall(
       return;
     }
     DataChannelSend(data_channel, type, data, std::move(result));
+  } else if (method_call.method_name().compare("dataChannelGetBufferedAmount") == 0) {
+    if (!method_call.arguments()) {
+      result->Error("Bad Arguments", "Null constraints arguments received");
+      return;
+    }
+    const EncodableMap params =
+        GetValue<EncodableMap>(*method_call.arguments());
+    const std::string peerConnectionId = findString(params, "peerConnectionId");
+    RTCPeerConnection* pc = PeerConnectionForId(peerConnectionId);
+    if (pc == nullptr) {
+      result->Error("dataChannelGetBufferedAmountFailed",
+                    "dataChannelGetBufferedAmount() peerConnection is null");
+      return;
+    }
+
+    const std::string dataChannelId = findString(params, "dataChannelId");
+    RTCDataChannel* data_channel = DataChannelForId(dataChannelId);
+    if (data_channel == nullptr) {
+      result->Error("dataChannelGetBufferedAmountFailed",
+                    "dataChannelGetBufferedAmount() data_channel is null");
+      return;
+    }
+    DataChannelGetBufferedAmount(data_channel, std::move(result));
   } else if (method_call.method_name().compare("dataChannelClose") == 0) {
     if (!method_call.arguments()) {
       result->Error("Bad Arguments", "Null constraints arguments received");

common/darwin/Classes/FlutterRTCDataChannel.h

@@ -24,4 +24,7 @@
                    data:(nonnull NSString*)data
                    type:(nonnull NSString*)type;
 
+- (void)dataChannelGetBufferedAmount:(nonnull NSString*)peerConnectionId
+          dataChannelId:(nonnull NSString*)dataChannelId 
+                result:(nonnull FlutterResult)result;
 @end

common/darwin/Classes/FlutterRTCDataChannel.m

@@ -118,6 +118,18 @@
   }
 }
 
+- (void)dataChannelGetBufferedAmount:(nonnull NSString*)peerConnectionId
+          dataChannelId:(nonnull NSString*)dataChannelId 
+                result:(nonnull FlutterResult)result {
+  RTCPeerConnection* peerConnection = self.peerConnections[peerConnectionId];
+  RTCDataChannel* dataChannel = peerConnection.dataChannels[dataChannelId];
+  if(dataChannel == NULL || dataChannel.readyState != RTCDataChannelStateOpen) {
+    result(@{@"bufferedAmount": @(-1)});
+  } else {
+    result(@{@"bufferedAmount": @(dataChannel.bufferedAmount)});
+  }
+}
+
 - (void)dataChannelSend:(nonnull NSString*)peerConnectionId
           dataChannelId:(nonnull NSString*)dataChannelId
                    data:(id)data

common/darwin/Classes/FlutterWebRTCPlugin.m

@@ -570,7 +570,14 @@ bypassVoiceProcessing:(BOOL)bypassVoiceProcessing {
 
     [self dataChannelSend:peerConnectionId dataChannelId:dataChannelId data:data type:type];
     result(nil);
-  } else if ([@"dataChannelClose" isEqualToString:call.method]) {
+  }  else if ([@"dataChannelGetBufferedAmount" isEqualToString:call.method]) {
+    NSDictionary* argsMap = call.arguments;
+    NSString* peerConnectionId = argsMap[@"peerConnectionId"];
+    NSString* dataChannelId = argsMap[@"dataChannelId"];
+
+    [self dataChannelGetBufferedAmount:peerConnectionId dataChannelId:dataChannelId result:result];
+  } 
+  else if ([@"dataChannelClose" isEqualToString:call.method]) {
     NSDictionary* argsMap = call.arguments;
     NSString* peerConnectionId = argsMap[@"peerConnectionId"];
     NSString* dataChannelId = argsMap[@"dataChannelId"];

example/lib/src/loopback_data_channel_sample.dart

@@ -49,12 +49,14 @@ class _DataChannelLoopBackSampleState extends State<DataChannelLoopBackSample> {
             _dataChannel2Status += '\ndataChannel2: state: ${state.toString()}';
           });
         };
-        _dataChannel2!.onMessage = (data) {
+        _dataChannel2!.onMessage = (data) async {
+          var bufferedAmount = await _dataChannel2!.getBufferedAmount();
           setState(() {
             _dataChannel2Status +=
-                '\ndataChannel2: Received message: ${data.text}';
+                '\ndataChannel2: Received message: ${data.text}, bufferedAmount: $bufferedAmount';
           });
-          _dataChannel2!.send(RTCDataChannelMessage(
+
+          await _dataChannel2!.send(RTCDataChannelMessage(
               '(dataChannel2 ==> dataChannel1) Hello from dataChannel2 echo !!!'));
         };
       };
@@ -69,10 +71,12 @@ class _DataChannelLoopBackSampleState extends State<DataChannelLoopBackSample> {
         }
       };
 
-      _dataChannel1!.onMessage = (data) => setState(() {
-            _dataChannel1Status +=
-                '\ndataChannel1: Received message: ${data.text}';
-          });
+      _dataChannel1!.onMessage = (data) async {
+        var bufferedAmount = await _dataChannel2!.getBufferedAmount();
+        _dataChannel1Status +=
+            '\ndataChannel1: Received message: ${data.text}, bufferedAmount: $bufferedAmount';
+        setState(() {});
+      };
 
       var offer = await _peerConnection1!.createOffer({});
       print('peerConnection1 offer: ${offer.sdp}');

lib/src/native/rtc_data_channel_impl.dart

@@ -109,6 +109,17 @@ class RTCDataChannelNative extends RTCDataChannel {
     }
   }
 
+  @override
+  Future<int> getBufferedAmount() async {
+    final Map<dynamic, dynamic> response = await WebRTC.invokeMethod(
+        'dataChannelGetBufferedAmount', <String, dynamic>{
+      'peerConnectionId': _peerConnectionId,
+      'dataChannelId': _flutterId
+    });
+    _bufferedAmount = response['bufferedAmount'];
+    return _bufferedAmount;
+  }
+
   @override
   Future<void> send(RTCDataChannelMessage message) async {
     await WebRTC.invokeMethod('dataChannelSend', <String, dynamic>{

pubspec.yaml

@@ -8,12 +8,12 @@ environment:
 
 dependencies:
   collection: ^1.17.0
-  dart_webrtc: ^1.5.2+hotfix.1
+  dart_webrtc: ^1.5.3
   flutter:
     sdk: flutter
   path_provider: ^2.0.2
   web: ^1.0.0
-  webrtc_interface: ^1.2.1+hotfix.1
+  webrtc_interface: ^1.2.2+hotfix.1
 
 dev_dependencies:
   flutter_test:

third_party/libwebrtc/include/rtc_data_channel.h

@@ -103,6 +103,13 @@ class RTCDataChannel : public RefCountInterface {
    */
   virtual int id() const = 0;
 
+  /**
+   * Returns the amount of data buffered in the data channel.
+   *
+   * @return uint64_t
+   */
+  virtual uint64_t buffered_amount() const = 0;
+
   /**
    * Returns the state of the data channel.
    */

third_party/libwebrtc/include/rtc_ice_transport.h

@@ -21,7 +21,8 @@
 #include "rtc_base/ref_count.h"
 
 namespace libwebrtc {
-class IceTransport : public rtc::RefCountInterface {
+
+class IceTransport : public RefCountInterface {
  public:
   virtual IceTransport* internal() = 0;
 };