| Index: sdk/lib/utf/utf_stream.dart
|
| diff --git a/sdk/lib/utf/utf_stream.dart b/sdk/lib/utf/utf_stream.dart
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..ad69c62441330f969b3c9cbcb86caa5f315aa82a
|
| --- /dev/null
|
| +++ b/sdk/lib/utf/utf_stream.dart
|
| @@ -0,0 +1,224 @@
|
| +// Copyright (c) 2013, 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.
|
| +
|
| +part of dart.utf;
|
| +
|
| +class _HelperStreamController<T> extends StreamController<T> {
|
| + final Function onPauseChanged;
|
| +
|
| + _HelperStreamController(this.onPauseChanged);
|
| +
|
| + void onPauseStateChange() {
|
| + onPauseChanged();
|
| + }
|
| +}
|
| +
|
| +abstract class _StringDecoder implements StreamTransformer<List<int>, String> {
|
| + _HelperStreamController<String> _controller;
|
| + StreamSubscription<List<int>> _subscription;
|
| + List<int> _carry;
|
| + List<int> _buffer;
|
| + int _replacementChar;
|
| + bool _paused = false;
|
| +
|
| + _StringDecoder(int this._replacementChar) {
|
| + _controller = new _HelperStreamController<String>(_onPauseChanged);
|
| + }
|
| +
|
| + void _onPauseChanged() {
|
| + _paused = _controller.isPaused;
|
| + if (_subscription == null) return;
|
| + if (_paused) {
|
| + _subscription.pause();
|
| + } else {
|
| + _subscription.resume();
|
| + }
|
| + }
|
| +
|
| + Stream<String> bind(Stream<List<int>> stream) {
|
| + _subscription = stream.listen(
|
| + _onData,
|
| + onError: _controller.signalError,
|
| + onDone: () {
|
| + if (_carry != null) {
|
| + _controller.add(new String.fromCharCodes(
|
| + new List.fixedLength(_carry.length, fill: _replacementChar)));
|
| + }
|
| + _controller.close();
|
| + },
|
| + unsubscribeOnError: false);
|
| + if (_paused) _subscription.pause();
|
| + return _controller.stream;
|
| + }
|
| +
|
| + void _onData(List<int> bytes) {
|
| + _buffer = <int>[];
|
| + List<int> carry = _carry;
|
| + _carry = null;
|
| + int pos = 0;
|
| + int available = bytes.length;
|
| + // If we have carry-over data, start from negative index, indicating carry
|
| + // index.
|
| + int goodChars = 0;
|
| + if (carry != null) pos = -carry.length;
|
| + while (pos < available) {
|
| + int currentPos = pos;
|
| + int getNext() {
|
| + if (pos < 0) {
|
| + return carry[pos++ + carry.length];
|
| + } else if (pos < available) {
|
| + return bytes[pos++];
|
| + }
|
| + return null;
|
| + }
|
| + int consumed = _processBytes(getNext);
|
| + if (consumed > 0) {
|
| + goodChars = _buffer.length;
|
| + } else if (consumed == 0) {
|
| + _buffer.length = goodChars;
|
| + if (currentPos < 0) {
|
| + _carry = [];
|
| + _carry.addAll(carry);
|
| + _carry.addAll(bytes);
|
| + } else {
|
| + _carry = bytes.getRange(currentPos, bytes.length - currentPos);
|
| + }
|
| + break;
|
| + } else {
|
| + // Invalid byte at position pos - 1
|
| + _buffer.length = goodChars;
|
| + _addChar(-1);
|
| + goodChars = _buffer.length;
|
| + }
|
| + }
|
| + if (_buffer.length > 0) {
|
| + // Limit to 'goodChars', if lower than actual charCodes in the buffer.
|
| + _controller.add(new String.fromCharCodes(_buffer));
|
| + }
|
| + _buffer = null;
|
| + }
|
| +
|
| + int _processBytes(int getNext());
|
| +
|
| + void _addChar(int char) {
|
| + if (char > 0x10FFFF || char < 0) char = _replacementChar;
|
| + _buffer.add(char);
|
| + }
|
| +}
|
| +
|
| +/**
|
| + * StringTransformer that decodes a stream of UTF-8 encoded bytes.
|
| + */
|
| +class Utf8DecoderTransformer extends _StringDecoder {
|
| + Utf8DecoderTransformer(
|
| + [int replacementChar = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT])
|
| + : super(replacementChar);
|
| +
|
| + int _processBytes(int getNext()) {
|
| + int value = getNext();
|
| + if ((value & 0xFF) != value) return -1; // Not a byte.
|
| + if ((value & 0x80) == 0x80) {
|
| + int additionalBytes;
|
| + int min;
|
| + if ((value & 0xe0) == 0xc0) { // 110xxxxx
|
| + value = value & 0x1F;
|
| + additionalBytes = 1;
|
| + min = 0x80;
|
| + } else if ((value & 0xf0) == 0xe0) { // 1110xxxx
|
| + value = value & 0x0F;
|
| + additionalBytes = 2;
|
| + min = 0x800;
|
| + } else if ((value & 0xf8) == 0xf0) { // 11110xxx
|
| + value = value & 0x07;
|
| + additionalBytes = 3;
|
| + min = 0x10000;
|
| + } else if ((value & 0xfc) == 0xf8) { // 111110xx
|
| + value = value & 0x03;
|
| + additionalBytes = 4;
|
| + min = 0x200000;
|
| + } else if ((value & 0xfe) == 0xfc) { // 1111110x
|
| + value = value & 0x01;
|
| + additionalBytes = 5;
|
| + min = 0x4000000;
|
| + } else {
|
| + return -1;
|
| + }
|
| + for (int i = 0; i < additionalBytes; i++) {
|
| + int next = getNext();
|
| + if (next == null) return 0; // Not enough chars, reset.
|
| + if ((next & 0xc0) != 0x80 || (next & 0xff) != next) return -1;
|
| + value = value << 6 | (next & 0x3f);
|
| + }
|
| + // Invalid charCode if less then minimum expected.
|
| + if (value < min) value = -1;
|
| + _addChar(value);
|
| + return 1 + additionalBytes;
|
| + }
|
| + _addChar(value);
|
| + return 1;
|
| + }
|
| +}
|
| +
|
| +
|
| +abstract class _StringEncoder implements StreamTransformer<String, List<int>> {
|
| + _HelperStreamController<List<int>> _controller;
|
| + StreamSubscription<String> _subscription;
|
| +
|
| + void _onPauseChanged() {
|
| + if (_controller.isPaused) {
|
| + _subscription.pause();
|
| + } else {
|
| + _subscription.resume();
|
| + }
|
| + }
|
| + Stream<List<int>> bind(Stream<String> stream) {
|
| + _controller = new _HelperStreamController(_onPauseChanged);
|
| + _subscription = stream.listen(
|
| + (string) => _controller.add(_processString(string)),
|
| + onError: _controller.signalError,
|
| + onDone: _controller.close,
|
| + unsubscribeOnError: false);
|
| + return _controller.stream;
|
| + }
|
| +
|
| + List<int> _processString(String string);
|
| +}
|
| +
|
| +/**
|
| + * StringTransformer that UTF-8 encodes a stream of strings.
|
| + */
|
| +class Utf8EncoderTransformer extends _StringEncoder {
|
| + List<int> _processString(String string) {
|
| + var bytes = [];
|
| + int pos = 0;
|
| + List<int> codepoints = _utf16CodeUnitsToCodepoints(string.charCodes);
|
| + int length = codepoints.length;
|
| + for (int i = 0; i < length; i++) {
|
| + int additionalBytes;
|
| + int charCode = codepoints[i];
|
| + if (charCode <= 0x007F) {
|
| + additionalBytes = 0;
|
| + bytes.add(charCode);
|
| + } else if (charCode <= 0x07FF) {
|
| + // 110xxxxx (xxxxx is top 5 bits).
|
| + bytes.add(((charCode >> 6) & 0x1F) | 0xC0);
|
| + additionalBytes = 1;
|
| + } else if (charCode <= 0xFFFF) {
|
| + // 1110xxxx (xxxx is top 4 bits)
|
| + bytes.add(((charCode >> 12) & 0x0F)| 0xE0);
|
| + additionalBytes = 2;
|
| + } else {
|
| + // 11110xxx (xxx is top 3 bits)
|
| + bytes.add(((charCode >> 18) & 0x07) | 0xF0);
|
| + additionalBytes = 3;
|
| + }
|
| + for (int i = additionalBytes; i > 0; i--) {
|
| + // 10xxxxxx (xxxxxx is next 6 bits from the top).
|
| + bytes.add(((charCode >> (6 * (i - 1))) & 0x3F) | 0x80);
|
| + }
|
| + pos += additionalBytes + 1;
|
| + }
|
| + return bytes;
|
| + }
|
| +}
|
|
|