fix missed exceptions for descriptors

shbae-musma · May 2, 2023 · f6d3e6d · f6d3e6d
1 parent a0dc6bd
commit f6d3e6d
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Showing 3 changed files with 57 additions and 71 deletions.
diff --git a/lib/src/bluetooth_characteristic.dart b/lib/src/bluetooth_characteristic.dart
@@ -94,14 +94,13 @@ class BluetoothCharacteristic {
             (p.characteristic.serviceUuid == request.serviceUuid))
         .map((p) => p.characteristic.value);
 
-    // Important: to not miss the result, we must listen
-    // for results *before* invoking 'readCharacteristic'
-    StreamBuf<List<int>> queue = StreamBuf(responseStream);
+    // Start listening now to ensure we don't miss the response
+    Future<List<int>> futureResponse = responseStream.first;
 
     await FlutterBluePlus.instance._channel
         .invokeMethod('readCharacteristic', request.writeToBuffer());
 
-    List<int> responseValue = await queue.next();
+    List<int> responseValue = await futureResponse;
 
     // Update the _value
     _value.add(responseValue);
@@ -137,15 +136,14 @@ class BluetoothCharacteristic {
             (p.request.characteristicUuid == request.characteristicUuid) &&
             (p.request.serviceUuid == request.serviceUuid));
 
-      // Important: to not miss the result, we must listen
-      // for results *before* invoking 'writeCharacteristic'
-      StreamBuf<protos.WriteCharacteristicResponse> queue = StreamBuf(responseStream);
+      // Start listening now to ensure we don't miss the response
+      Future<protos.WriteCharacteristicResponse> futureResponse = responseStream.first;
 
       await FlutterBluePlus.instance._channel
         .invokeMethod('writeCharacteristic', request.writeToBuffer());
 
       // wait for response, so that we can check for success
-      protos.WriteCharacteristicResponse response = await queue.next();
+      protos.WriteCharacteristicResponse response = await futureResponse;
       if (!response.success) {
         throw Exception('Failed to write the characteristic');
       }

diff --git a/lib/src/bluetooth_descriptor.dart b/lib/src/bluetooth_descriptor.dart
@@ -32,56 +32,71 @@ class BluetoothDescriptor {
       ..characteristicUuid = characteristicUuid.toString()
       ..serviceUuid = serviceUuid.toString();
 
+    Stream<protos.ReadDescriptorResponse> responseStream =
+        FlutterBluePlus.instance._methodStream
+            .where((m) => m.method == "ReadDescriptorResponse")
+            .map((m) => m.arguments)
+            .map((buffer) => protos.ReadDescriptorResponse.fromBuffer(buffer))
+            .where((p) =>
+                (p.request.remoteId == request.remoteId) &&
+                (p.request.descriptorUuid == request.descriptorUuid) &&
+                (p.request.characteristicUuid == request.characteristicUuid) &&
+                (p.request.serviceUuid == request.serviceUuid));
+
+    // Start listening now to ensure we don't miss the response
+    Future<protos.ReadDescriptorResponse> futureResponse = responseStream.first;
+
     await FlutterBluePlus.instance._channel
-        .invokeMethod('readDescriptor', request.writeToBuffer());
-
-    return FlutterBluePlus.instance._methodStream
-        .where((m) => m.method == "ReadDescriptorResponse")
-        .map((m) => m.arguments)
-        .map((buffer) => protos.ReadDescriptorResponse.fromBuffer(buffer))
-        .where((p) =>
-            (p.request.remoteId == request.remoteId) &&
-            (p.request.descriptorUuid == request.descriptorUuid) &&
-            (p.request.characteristicUuid == request.characteristicUuid) &&
-            (p.request.serviceUuid == request.serviceUuid))
-        .map((d) => d.value)
-        .first
-        .then((d) {
-      _value.add(d);
-      return d;
-    });
+      .invokeMethod('readDescriptor', request.writeToBuffer());
+
+    protos.ReadDescriptorResponse response = await futureResponse;
+
+    List<int> readValue = response.value;
+
+    _value.add(readValue);
+
+    return readValue;
   }
 
+
   /// Writes the value of a descriptor
-  Future<Null> write(List<int> value) async {
+  Future<void> write(List<int> value) async {
     var request = protos.WriteDescriptorRequest.create()
       ..remoteId = deviceId.toString()
       ..descriptorUuid = uuid.toString()
       ..characteristicUuid = characteristicUuid.toString()
       ..serviceUuid = serviceUuid.toString()
       ..value = value;
 
+    Stream<protos.WriteDescriptorResponse> responseStream =
+        FlutterBluePlus.instance._methodStream
+            .where((m) => m.method == "WriteDescriptorResponse")
+            .map((m) => m.arguments)
+            .map((buffer) => protos.WriteDescriptorResponse.fromBuffer(buffer))
+            .where((p) =>
+                (p.request.remoteId == request.remoteId) &&
+                (p.request.descriptorUuid == request.descriptorUuid) &&
+                (p.request.characteristicUuid == request.characteristicUuid) &&
+                (p.request.serviceUuid == request.serviceUuid));
+
+    // Start listening now to ensure we don't miss the response
+    Future<protos.WriteDescriptorResponse> futureResponse = responseStream.first;
+
     await FlutterBluePlus.instance._channel
-        .invokeMethod('writeDescriptor', request.writeToBuffer());
-
-    return FlutterBluePlus.instance._methodStream
-        .where((m) => m.method == "WriteDescriptorResponse")
-        .map((m) => m.arguments)
-        .map((buffer) => protos.WriteDescriptorResponse.fromBuffer(buffer))
-        .where((p) =>
-            (p.request.remoteId == request.remoteId) &&
-            (p.request.descriptorUuid == request.descriptorUuid) &&
-            (p.request.characteristicUuid == request.characteristicUuid) &&
-            (p.request.serviceUuid == request.serviceUuid))
-        .first
-        .then((w) => w.success)
-        .then((success) => (!success)
-            ? throw Exception('Failed to write the descriptor')
-            : null)
-        .then((_) => _value.add(value))
-        .then((_) => null);
+          .invokeMethod('writeDescriptor', request.writeToBuffer());
+
+    protos.WriteDescriptorResponse response = await futureResponse;
+
+    if (!response.success) {
+      throw Exception('Failed to write the descriptor');
+    }
+
+    _value.add(value);
+
+    return Future.value();
   }
 
+
   @override
   String toString() {
     return 'BluetoothDescriptor{uuid: $uuid, deviceId: $deviceId, serviceUuid: $serviceUuid, characteristicUuid: $characteristicUuid, value: ${_value.value}}';

diff --git a/lib/src/utils.dart b/lib/src/utils.dart
@@ -194,30 +194,3 @@ Stream<T> mergeStreams<T>(List<Stream<T>> streams) {
 
   return controller.stream;
 }
-
-// caches all items received
-// this lets us access the items at a later time
-class StreamBuf<T> {
-  final Stream<T> _stream;
-  final List<T> _buffer = [];
-  Completer<void> _completer = Completer<void>();
-
-  StreamBuf(this._stream) {
-    _stream.listen((event) {
-      _buffer.add(event);
-      if (!_completer.isCompleted) {
-        _completer.complete();
-      }
-    });
-  }
-
-  Future<T> next() async {
-    if (_buffer.isNotEmpty) {
-      return _buffer.removeAt(0);
-    } else {
-      await _completer.future;
-      _completer = Completer<void>();
-      return _buffer.removeAt(0);
-    }
-  }
-}