Cleanup in BoundMultipartStream (#35)
Start to make the code a little easier to understand, and fix some
style.
- Initialize the `_controller` field in place and make it final. Set the
callbacks in the constructor rather than instantiate in the
constructor. This will prevent it from needing to be `late`.
- Assign `boundaryPrefix`, `contentStartIndex`, and `byte` variables
where they are declared rather than separate the declaration and
initialization.
Style fixes:
- Use doc comments.
- Remove unnecessary parens in while loop condition.
- Remove unnecessary library directive.
diff --git a/lib/src/bound_multipart_stream.dart b/lib/src/bound_multipart_stream.dart
index 07418b2..71c77f9 100644
--- a/lib/src/bound_multipart_stream.dart
+++ b/lib/src/bound_multipart_stream.dart
@@ -1,7 +1,6 @@
// Copyright (c) 2014, 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.
-library mime.bound_multipart_stream;
import 'dart:async';
import 'dart:convert';
@@ -9,7 +8,7 @@
import 'char_code.dart';
import 'mime_shared.dart';
-// Bytes for '()<>@,;:\\"/[]?={} \t'.
+/// Bytes for '()<>@,;:\\"/[]?={} \t'.
const _SEPARATORS = [
40,
41,
@@ -102,7 +101,7 @@
int _controllerState = _CONTROLLER_STATE_IDLE;
- StreamController<MimeMultipart> _controller;
+ final _controller = StreamController<MimeMultipart>(sync: true);
Stream<MimeMultipart> get stream => _controller.stream;
@@ -114,36 +113,37 @@
int _state = _START;
int _boundaryIndex = 2;
- // Current index in the data buffer. If index is negative then it
- // is the index into the artificial prefix of the boundary string.
+ /// Current index into [_buffer].
+ ///
+ /// If index is negative then it is the index into the artificial prefix of
+ /// the boundary string.
int _index;
List<int> _buffer;
BoundMultipartStream(this._boundary, Stream<List<int>> stream) {
- _controller = StreamController(
- sync: true,
- onPause: _pauseStream,
- onResume: _resumeStream,
- onCancel: () {
- _controllerState = _CONTROLLER_STATE_CANCELED;
- _tryPropagateControllerState();
- },
- onListen: () {
- _controllerState = _CONTROLLER_STATE_ACTIVE;
- _subscription = stream.listen((data) {
- assert(_buffer == null);
- _subscription.pause();
- _buffer = data;
- _index = 0;
- _parse();
- }, onDone: () {
- if (_state != _DONE) {
- _controller
- .addError(MimeMultipartException('Bad multipart ending'));
- }
- _controller.close();
- }, onError: _controller.addError);
- });
+ _controller
+ ..onPause = _pauseStream
+ ..onResume = _resumeStream
+ ..onCancel = () {
+ _controllerState = _CONTROLLER_STATE_CANCELED;
+ _tryPropagateControllerState();
+ }
+ ..onListen = () {
+ _controllerState = _CONTROLLER_STATE_ACTIVE;
+ _subscription = stream.listen((data) {
+ assert(_buffer == null);
+ _subscription.pause();
+ _buffer = data;
+ _index = 0;
+ _parse();
+ }, onDone: () {
+ if (_state != _DONE) {
+ _controller
+ .addError(MimeMultipartException('Bad multipart ending'));
+ }
+ _controller.close();
+ }, onError: _controller.addError);
+ };
}
void _resumeStream() {
@@ -177,12 +177,15 @@
void _parse() {
// Number of boundary bytes to artificially place before the supplied data.
- var boundaryPrefix = 0;
+ // The data to parse might be 'artificially' prefixed with a
+ // partial match of the boundary.
+ var boundaryPrefix = _boundaryIndex;
// Position where content starts. Will be null if no known content
// start exists. Will be negative of the content starts in the
// boundary prefix. Will be zero or position if the content starts
// in the current buffer.
- int contentStartIndex;
+ var contentStartIndex =
+ _state == _CONTENT && _boundaryIndex == 0 ? 0 : null;
// Function to report content data for the current part. The data
// reported is from the current content start index up til the
@@ -206,22 +209,9 @@
}
}
- if (_state == _CONTENT && _boundaryIndex == 0) {
- contentStartIndex = 0;
- } else {
- contentStartIndex = null;
- }
- // The data to parse might be 'artificially' prefixed with a
- // partial match of the boundary.
- boundaryPrefix = _boundaryIndex;
-
- while ((_index < _buffer.length) && _state != _FAIL && _state != _DONE) {
- int byte;
- if (_index < 0) {
- byte = _boundary[boundaryPrefix + _index];
- } else {
- byte = _buffer[_index];
- }
+ while (_index < _buffer.length && _state != _FAIL && _state != _DONE) {
+ var byte =
+ _index < 0 ? _boundary[boundaryPrefix + _index] : _buffer[_index];
switch (_state) {
case _START:
if (byte == _boundary[_boundaryIndex]) {
