| // Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'digest.dart'; |
| |
| /// A sink used to get a digest value out of `Hash.startChunkedConversion`. |
| class DigestSink extends Sink<Digest> { |
| /// The value added to the sink, if any. |
| Digest get value { |
| assert(_value != null); |
| return _value; |
| } |
| |
| Digest _value; |
| |
| /// Adds [value] to the sink. |
| /// |
| /// Unlike most sinks, this may only be called once. |
| @override |
| void add(Digest value) { |
| assert(_value == null); |
| _value = value; |
| } |
| |
| @override |
| void close() { |
| assert(_value != null); |
| } |
| } |