| // Copyright (c) 2016, 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 'dart:io'; |
| |
| import 'message_grouper.dart'; |
| import 'message_grouper_state.dart'; |
| |
| /// Groups bytes in delimited proto format into the bytes for each message. |
| class SyncMessageGrouper implements MessageGrouper { |
| final _state = MessageGrouperState(); |
| final Stdin _stdin; |
| |
| SyncMessageGrouper(this._stdin); |
| |
| /// Blocks until the next full message is received, and then returns it. |
| /// |
| /// Returns null at end of file. |
| @override |
| List<int>? get next { |
| try { |
| List<int>? message; |
| while (message == null) { |
| var nextByte = _stdin.readByteSync(); |
| if (nextByte == -1) return null; |
| message = _state.handleInput(nextByte); |
| } |
| return message; |
| } catch (e) { |
| // It appears we sometimes get an exception instead of -1 as expected when |
| // stdin closes, this handles that in the same way (returning a null |
| // message) |
| return null; |
| } |
| } |
| } |