feat: add writeCharacteristicWithoutResponseBatch for bulk transfers

packages/flutter_reactive_ble/lib/src/connected_device_operation.dart

@@ -17,6 +17,12 @@ abstract class ConnectedDeviceOperation {
     required List<int> value,
   });
 
+  Future<void> writeCharacteristicWithoutResponseBatch(
+    CharacteristicInstance characteristic, {
+    required List<int> value,
+    int? packetSize,
+  });
+
   Stream<List<int>> subscribeToCharacteristic(
     CharacteristicInstance characteristic,
     Future<void> isDisconnected,
@@ -76,6 +82,20 @@ class ConnectedDeviceOperationImpl implements ConnectedDeviceOperation {
           .writeCharacteristicWithoutResponse(characteristic, value)
           .then((info) => info.result.dematerialize());
 
+  @override
+  Future<void> writeCharacteristicWithoutResponseBatch(
+    CharacteristicInstance characteristic, {
+    required List<int> value,
+    int? packetSize,
+  }) async =>
+      _blePlatform
+          .writeCharacteristicWithoutResponseBatch(
+            characteristic,
+            value,
+            packetSize: packetSize,
+          )
+          .then((info) => info.result.dematerialize());
+
   @override
   Stream<List<int>> subscribeToCharacteristic(
     CharacteristicInstance characteristic,

packages/flutter_reactive_ble/lib/src/reactive_ble.dart

@@ -200,6 +200,53 @@ class FlutterReactiveBle {
     await (await resolveSingle(characteristic)).write(value, withResponse: false);
   }
 
+  /// Writes [value] without response as a sequence of packets, sent back to
+  /// back by the platform without returning to the dart layer between packets.
+  ///
+  /// This reduces per-write overhead for bulk transfers such as firmware
+  /// updates: every packet is filled up to the maximum size and the
+  /// dart <-> platform round trip per write is removed, which awaiting
+  /// [writeCharacteristicWithoutResponse] per packet would incur. The BLE stack
+  /// may still send only one packet per connection event.
+  ///
+  /// By default packets are (MTU - 3) bytes. Set [packetSize] when the
+  /// peripheral expects a fixed frame per ATT write; the value is split into
+  /// packets of that many bytes (the last one may be shorter). It must be
+  /// positive and must not exceed (MTU - 3): iOS and macOS clamp it to
+  /// `maximumWriteValueLength`, Android does not check it. Protocols with a
+  /// frame below (MTU - 3) only gain the saved round trips. A null [packetSize]
+  /// uses the platform default.
+  ///
+  /// Packets are sent in order. The returned future completes when the last
+  /// packet has been accepted by the platform BLE stack (not when the device has
+  /// processed it), or with an error on the first failure; in that case, packets
+  /// before the failure may already have been sent.
+  ///
+  /// Negotiate the MTU with [requestMtu] first. Keep [value] no larger than
+  /// what the device can buffer, and confirm reception between batches
+  /// (e.g. via a notification) as write-without-response has no acknowledgement.
+  ///
+  /// Throws an [ArgumentError] if [packetSize] is not positive.
+  Future<void> writeCharacteristicWithoutResponseBatch(
+    QualifiedCharacteristic characteristic, {
+    required List<int> value,
+    int? packetSize,
+  }) async {
+    if (packetSize != null && packetSize <= 0) {
+      throw ArgumentError.value(
+          packetSize, 'packetSize', 'must be greater than 0');
+    }
+    if (value.isEmpty) return;
+    await initialize();
+    final resolved = await resolveSingle(characteristic);
+    resolved._assertValidity();
+    await _connectedDeviceOperator.writeCharacteristicWithoutResponseBatch(
+      resolved._ids,
+      value: value,
+      packetSize: packetSize,
+    );
+  }
+
   /// Request a specific MTU for a connected device.
   ///
   /// Returns the actual MTU negotiated.

packages/flutter_reactive_ble/test/connected_device_operation_test.mocks.dart

@@ -1,4 +1,4 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.4 from annotations
 // in flutter_reactive_ble/test/connected_device_operation_test.dart.
 // Do not manually edit this file.
 
@@ -14,6 +14,8 @@ import 'package:reactive_ble_platform_interface/src/reactive_ble_platform_interf
 // ignore_for_file: avoid_redundant_argument_values
 // ignore_for_file: avoid_setters_without_getters
 // ignore_for_file: comment_references
+// ignore_for_file: deprecated_member_use
+// ignore_for_file: deprecated_member_use_from_same_package
 // ignore_for_file: implementation_imports
 // ignore_for_file: invalid_use_of_visible_for_testing_member
 // ignore_for_file: prefer_const_constructors
@@ -68,23 +70,27 @@ class MockReactiveBlePlatform extends _i1.Mock
         Invocation.getter(#scanStream),
         returnValue: _i4.Stream<_i2.ScanResult>.empty(),
       ) as _i4.Stream<_i2.ScanResult>);
+
   @override
   _i4.Stream<_i2.BleStatus> get bleStatusStream => (super.noSuchMethod(
         Invocation.getter(#bleStatusStream),
         returnValue: _i4.Stream<_i2.BleStatus>.empty(),
       ) as _i4.Stream<_i2.BleStatus>);
+
   @override
   _i4.Stream<_i2.ConnectionStateUpdate> get connectionUpdateStream =>
       (super.noSuchMethod(
         Invocation.getter(#connectionUpdateStream),
         returnValue: _i4.Stream<_i2.ConnectionStateUpdate>.empty(),
       ) as _i4.Stream<_i2.ConnectionStateUpdate>);
+
   @override
   _i4.Stream<_i2.CharacteristicValue> get charValueUpdateStream =>
       (super.noSuchMethod(
         Invocation.getter(#charValueUpdateStream),
         returnValue: _i4.Stream<_i2.CharacteristicValue>.empty(),
       ) as _i4.Stream<_i2.CharacteristicValue>);
+
   @override
   _i4.Future<void> initialize() => (super.noSuchMethod(
         Invocation.method(
@@ -94,6 +100,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<void>.value(),
         returnValueForMissingStub: _i4.Future<void>.value(),
       ) as _i4.Future<void>);
+
   @override
   _i4.Future<void> deinitialize() => (super.noSuchMethod(
         Invocation.method(
@@ -103,6 +110,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<void>.value(),
         returnValueForMissingStub: _i4.Future<void>.value(),
       ) as _i4.Future<void>);
+
   @override
   _i4.Stream<void> scanForDevices({
     required List<_i2.Uuid>? withServices,
@@ -121,6 +129,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Stream<void>.empty(),
       ) as _i4.Stream<void>);
+
   @override
   _i4.Future<_i2.Result<_i2.Unit, _i2.GenericFailure<_i2.ClearGattCacheError>?>>
       clearGattCache(String? deviceId) => (super.noSuchMethod(
@@ -140,8 +149,9 @@ class MockReactiveBlePlatform extends _i1.Mock
               ),
             )),
           ) as _i4.Future<
-              _i2.Result<_i2.Unit,
-                  _i2.GenericFailure<_i2.ClearGattCacheError>?>>);
+              _i2
+              .Result<_i2.Unit, _i2.GenericFailure<_i2.ClearGattCacheError>?>>);
+
   @override
   _i4.Future<int> readRssi(String? deviceId) => (super.noSuchMethod(
         Invocation.method(
@@ -150,6 +160,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Future<int>.value(0),
       ) as _i4.Future<int>);
+
   @override
   _i4.Stream<void> connectToDevice(
     String? id,
@@ -167,6 +178,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Stream<void>.empty(),
       ) as _i4.Stream<void>);
+
   @override
   _i4.Future<void> disconnectDevice(String? deviceId) => (super.noSuchMethod(
         Invocation.method(
@@ -176,6 +188,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<void>.value(),
         returnValueForMissingStub: _i4.Future<void>.value(),
       ) as _i4.Future<void>);
+
   @override
   _i4.Future<List<_i2.DiscoveredService>> discoverServices(String? deviceId) =>
       (super.noSuchMethod(
@@ -186,6 +199,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<List<_i2.DiscoveredService>>.value(
             <_i2.DiscoveredService>[]),
       ) as _i4.Future<List<_i2.DiscoveredService>>);
+
   @override
   _i4.Future<List<_i2.DiscoveredService>> getDiscoverServices(
           String? deviceId) =>
@@ -197,6 +211,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<List<_i2.DiscoveredService>>.value(
             <_i2.DiscoveredService>[]),
       ) as _i4.Future<List<_i2.DiscoveredService>>);
+
   @override
   _i4.Stream<void> readCharacteristic(
           _i2.CharacteristicInstance? characteristic) =>
@@ -207,6 +222,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Stream<void>.empty(),
       ) as _i4.Stream<void>);
+
   @override
   _i4.Future<_i2.WriteCharacteristicInfo> writeCharacteristicWithResponse(
     _i2.CharacteristicInstance? characteristic,
@@ -232,6 +248,7 @@ class MockReactiveBlePlatform extends _i1.Mock
           ),
         )),
       ) as _i4.Future<_i2.WriteCharacteristicInfo>);
+
   @override
   _i4.Future<_i2.WriteCharacteristicInfo> writeCharacteristicWithoutResponse(
     _i2.CharacteristicInstance? characteristic,
@@ -257,6 +274,37 @@ class MockReactiveBlePlatform extends _i1.Mock
           ),
         )),
       ) as _i4.Future<_i2.WriteCharacteristicInfo>);
+
+  @override
+  _i4.Future<_i2.WriteCharacteristicInfo>
+      writeCharacteristicWithoutResponseBatch(
+    _i2.CharacteristicInstance? characteristic,
+    List<int>? value, {
+    int? packetSize,
+  }) =>
+          (super.noSuchMethod(
+            Invocation.method(
+              #writeCharacteristicWithoutResponseBatch,
+              [
+                characteristic,
+                value,
+              ],
+              {#packetSize: packetSize},
+            ),
+            returnValue: _i4.Future<_i2.WriteCharacteristicInfo>.value(
+                _FakeWriteCharacteristicInfo_1(
+              this,
+              Invocation.method(
+                #writeCharacteristicWithoutResponseBatch,
+                [
+                  characteristic,
+                  value,
+                ],
+                {#packetSize: packetSize},
+              ),
+            )),
+          ) as _i4.Future<_i2.WriteCharacteristicInfo>);
+
   @override
   _i4.Stream<void> subscribeToNotifications(
           _i2.CharacteristicInstance? characteristic) =>
@@ -267,6 +315,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Stream<void>.empty(),
       ) as _i4.Stream<void>);
+
   @override
   _i4.Future<void> stopSubscribingToNotifications(
           _i2.CharacteristicInstance? characteristic) =>
@@ -278,6 +327,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         returnValue: _i4.Future<void>.value(),
         returnValueForMissingStub: _i4.Future<void>.value(),
       ) as _i4.Future<void>);
+
   @override
   _i4.Future<int> requestMtuSize(
     String? deviceId,
@@ -293,6 +343,7 @@ class MockReactiveBlePlatform extends _i1.Mock
         ),
         returnValue: _i4.Future<int>.value(0),
       ) as _i4.Future<int>);
+
   @override
   _i4.Future<_i2.ConnectionPriorityInfo> requestConnectionPriority(
     String? deviceId,