readBuffer method

@override Future<ByteData> readBuffer(StorageBuffer buffer)

Zeros of the buffer's length: a fake keeps no bytes. Refused for a buffer that was not made host-readable, as every backend refuses it.

Implementation

@override
Future<ByteData> readBuffer(StorageBuffer buffer) async {
  features.require(DeviceFeature.buffers, backend: _name);
  if (!buffer.hostReadable) {
    throw ArgumentError.value(buffer, 'buffer', 'is not hostReadable');
  }
  return ByteData(buffer.lengthInBytes);
}