Merge IO v2 branch to bleeding edge

sdk/lib/io/string_stream.dart

 // 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.io;
-
-// Interface for decoders decoding binary data into string data. The
-// decoder keeps track of line breaks during decoding.
-abstract class _StringDecoder {
-  // Add more binary data to be decoded. The ownership of the buffer
-  // is transfered to the decoder and the caller most not modify it any more.
-  int write(List<int> buffer);
-
-  void done();
-
-  // Returns whether any decoded data is available.
-  bool get isEmpty;
-
-  // Returns the number of available decoded characters.
-  int available();
-
-  // Get the number of line breaks present in the current decoded
-  // data.
-  int get lineBreaks;
-
-  // Get up to [len] characters of string data decoded since the last
-  // call to [decode] or [decodeLine]. Returns null if no decoded data
-  // is available. If [len] is not specified all decoded characters
-  // are returned.
-  String decoded([int len]);
-
-  // Get the string data decoded since the last call to [decode] or
-  // [decodeLine] up to the next line break present. Returns null if
-  // no line break is present. The line break character sequence is
-  // discarded.
-  String get decodedLine;
-
-  // Set the handler that will be called if an error ocurs while decoding.
-  void set onError(Function callback);
-}
-
-
-class _StringDecoders {
-  static _StringDecoder decoder(Encoding encoding) {
-    if (encoding == Encoding.UTF_8) {
-      return new _UTF8Decoder();
-    } else if (encoding == Encoding.ISO_8859_1) {
-      return new _Latin1Decoder();
-    } else if (encoding == Encoding.ASCII) {
-      return new _AsciiDecoder();
-    } else if (encoding == Encoding.SYSTEM) {
-      if (Platform.operatingSystem == 'windows') {
-        return new _WindowsCodePageDecoder();
-      }
-      return new _UTF8Decoder();
-    } else {
-      if (encoding is Encoding) {
-        throw new StreamException("Unsupported encoding ${encoding.name}");
-      } else {
-        throw new StreamException("Unsupported encoding ${encoding}");
-      }
-    }
-  }
-}
-
-
-class DecoderException implements Exception {
-  const DecoderException([String this.message]);
-  String toString() => "DecoderException: $message";
-  final String message;
-}
-
-
-// Utility class for decoding UTF-8 from data delivered as a stream of
-// bytes.
-abstract class _StringDecoderBase implements _StringDecoder {
-  _StringDecoderBase()
-      : _bufferList = new _BufferList(),
-        _result = new List<int>(),
-        _lineBreakEnds = new Queue<int>();
-
-  int write(List<int> buffer) {
-    _bufferList.add(buffer);
-    // Decode as many bytes into characters as possible.
-    while (_bufferList.length > 0) {
-      if (!_processNext()) {
-        break;
-      }
-    }
-    return buffer.length;
-  }
-
-  void done() { }
-
-  bool get isEmpty => _result.isEmpty;
-
-  int get lineBreaks => _lineBreaks;
-
-  String decoded([int length]) {
-    if (isEmpty) return null;
-
-    List<int> result;
-    if (length != null && length < available()) {
-      result = _result.getRange(_resultOffset, length);
-    } else if (_resultOffset == 0) {
-      result = _result;
-    } else {
-      result = _result.getRange(_resultOffset, _result.length - _resultOffset);
-    }
-
-    _resultOffset += result.length;
-    while (!_lineBreakEnds.isEmpty &&
-           _lineBreakEnds.first < _charOffset + _resultOffset) {
-      _lineBreakEnds.removeFirst();
-      _lineBreaks--;
-    }
-    if (_result.length == _resultOffset) _resetResult();
-    return new String.fromCharCodes(result);
-  }
-
-  String get decodedLine {
-    if (_lineBreakEnds.isEmpty) return null;
-    int lineEnd = _lineBreakEnds.removeFirst();
-    int terminationSequenceLength = 1;
-    if (_result[lineEnd - _charOffset] == LF &&
-        lineEnd > _charOffset &&
-        _resultOffset < lineEnd &&
-        _result[lineEnd - _charOffset - 1] == CR) {
-      terminationSequenceLength = 2;
-    }
-    var lineLength =
-        lineEnd - _charOffset - _resultOffset - terminationSequenceLength + 1;
-    String result =
-        new String.fromCharCodes(_result.getRange(_resultOffset, lineLength));
-    _lineBreaks--;
-    _resultOffset += (lineLength + terminationSequenceLength);
-    if (_result.length == _resultOffset) _resetResult();
-    return result;
-  }
-
-  // Add another decoded character.
-  void addChar(int charCode) {
-    _result.add(charCode);
-    _charCount++;
-    // Check for line ends (\r, \n and \r\n).
-    if (charCode == LF) {
-      _recordLineBreakEnd(_charCount - 1);
-    } else if (_lastCharCode == CR) {
-      _recordLineBreakEnd(_charCount - 2);
-    }
-    _lastCharCode = charCode;
-  }
-
-  int available() => _result.length - _resultOffset;
-
-  void _recordLineBreakEnd(int charPos) {
-    _lineBreakEnds.add(charPos);
-    _lineBreaks++;
-  }
-
-  void _resetResult() {
-    _charOffset += _result.length;
-    _result = new List<int>();
-    _resultOffset = 0;
-  }
-
-  bool _processNext();
-
-  _BufferList _bufferList;
-  int _resultOffset = 0;
-  List<int> _result;
-  int _lineBreaks = 0;  // Number of line breaks in the current list.
-  // The positions of the line breaks are tracked in terms of absolute
-  // character positions from the begining of the decoded data.
-  Queue<int> _lineBreakEnds;  // Character position of known line breaks.
-  int _charOffset = 0;  // Character number of the first character in the list.
-  int _charCount = 0;  // Total number of characters decoded.
-  int _lastCharCode = -1;
-  Function onError;
-
-  final int LF = 10;
-  final int CR = 13;
-}
-
-
-// Utility class for decoding UTF-8 from data delivered as a stream of
-// bytes.
-class _UTF8Decoder extends _StringDecoderBase {
-  static const kMaxCodePoint = 0x10FFFF;
-  static const kReplacementCodePoint = 0x3f;
-
-  void done() {
-    if (!_bufferList.isEmpty) {
-      _reportError(new DecoderException("Illegal UTF-8"));
-    }
-  }
-
-  bool _reportError(error) {
-    if (onError != null) {
-      onError(error);
-      return false;
-    } else {
-      throw error;
-    }
-  }
-
-  // Process the next UTF-8 encoded character.
-  bool _processNext() {
-    // Peek the next byte to calculate the number of bytes required for
-    // the next character.
-    int value = _bufferList.peek() & 0xFF;
-    if ((value & 0x80) == 0x80) {
-      int additionalBytes;
-      if ((value & 0xe0) == 0xc0) {  // 110xxxxx
-        value = value & 0x1F;
-        additionalBytes = 1;
-      } else if ((value & 0xf0) == 0xe0) {  // 1110xxxx
-        value = value & 0x0F;
-        additionalBytes = 2;
-      } else if ((value & 0xf8) == 0xf0) {  // 11110xxx
-        value = value & 0x07;
-        additionalBytes = 3;
-      } else if ((value & 0xfc) == 0xf8) {  // 111110xx
-        value = value & 0x03;
-        additionalBytes = 4;
-      } else if ((value & 0xfe) == 0xfc) {  // 1111110x
-        value = value & 0x01;
-        additionalBytes = 5;
-      } else {
-        return _reportError(new DecoderException("Illegal UTF-8"));
-      }
-      // Check if there are enough bytes to decode the character. Otherwise
-      // return false.
-      if (_bufferList.length < additionalBytes + 1) {
-        return false;
-      }
-      // Remove the value peeked from the buffer list.
-      _bufferList.next();
-      for (int i = 0; i < additionalBytes; i++) {
-        int byte = _bufferList.next();
-        if ((byte & 0xc0) != 0x80) {
-          return _reportError(new DecoderException("Illegal UTF-8"));
-        }
-        value = value << 6 | (byte & 0x3F);
-      }
-    } else {
-      // Remove the value peeked from the buffer list.
-      _bufferList.next();
-    }
-    if (value > kMaxCodePoint) {
-      addChar(kReplacementCodePoint);
-    } else {
-      addChar(value);
-    }
-    return true;
-  }
-}
-
-
-// Utility class for decoding ascii data delivered as a stream of
-// bytes.
-class _AsciiDecoder extends _StringDecoderBase {
-  // Process the next ascii encoded character.
-  bool _processNext() {
-    while (_bufferList.length > 0) {
-      int byte = _bufferList.next();
-      if (byte > 127) {
-        var error = new DecoderException("Illegal ASCII character $byte");
-        if (onError != null) {
-          onError(error);
-          return false;
-        } else {
-          throw error;
-        }
-      }
-      addChar(byte);
-    }
-    return true;
-  }
-}
-
-
-// Utility class for decoding Latin-1 data delivered as a stream of
-// bytes.
-class _Latin1Decoder extends _StringDecoderBase {
-  // Process the next Latin-1 encoded character.
-  bool _processNext() {
-    while (_bufferList.length > 0) {
-      int byte = _bufferList.next();
-      addChar(byte);
-    }
-    return true;
-  }
-}
-
-
-// Utility class for decoding Windows current code page data delivered
-// as a stream of bytes.
-class _WindowsCodePageDecoder extends _StringDecoderBase {
-  // Process the next chunk of data.
-  bool _processNext() {
-    List<int> bytes = _bufferList.readBytes(_bufferList.length);
-    for (var charCode in _decodeBytes(bytes).charCodes) {
-      addChar(charCode);
-    }
-    return true;
-  }
-
-  external static String _decodeBytes(List<int> bytes);
-}
-
-
-// Interface for encoders encoding string data into binary data.
-abstract class _StringEncoder {
-  List<int> encodeString(String string);
-}
-
-
-// Utility class for encoding a string into UTF-8 byte stream.
-class _UTF8Encoder implements _StringEncoder {
-  List<int> encodeString(String string) {
-    int size = _encodingSize(string);
-    List<int> result = new Uint8List(size);
-    _encodeString(string, result);
-    return result;
-  }
-
-  static int _encodingSize(String string) => _encodeString(string, null);
-
-  static int _encodeString(String string, List<int> buffer) {
-    List<int> utf8CodeUnits = encodeUtf8(string);
-    if (buffer != null) {
-      for (int i = 0; i < utf8CodeUnits.length; i++) {
-        buffer[i] = utf8CodeUnits[i];
-      }
-    }
-    return utf8CodeUnits.length;
-  }
-}
-
-
-// Utility class for encoding a string into a Latin1 byte stream.
-class _Latin1Encoder implements _StringEncoder {
-  List<int> encodeString(String string) {
-    List<int> result = new Uint8List(string.length);
-    for (int i = 0; i < string.length; i++) {
-      int charCode = string.charCodeAt(i);
-      if (charCode > 255) {
-        throw new EncoderException(
-            "No ISO_8859_1 encoding for code point $charCode");
-      }
-      result[i] = charCode;
-    }
-    return result;
-  }
-}
-
-
-// Utility class for encoding a string into an ASCII byte stream.
-class _AsciiEncoder implements _StringEncoder {
-  List<int> encodeString(String string) {
-    List<int> result = new Uint8List(string.length);
-    for (int i = 0; i < string.length; i++) {
-      int charCode = string.charCodeAt(i);
-      if (charCode > 127) {
-        throw new EncoderException(
-            "No ASCII encoding for code point $charCode");
-      }
-      result[i] = charCode;
-    }
-    return result;
-  }
-}
-
-
-// Utility class for encoding a string into a current windows
-// code page byte list.
-class _WindowsCodePageEncoder implements _StringEncoder {
-  List<int> encodeString(String string) {
-    return _encodeString(string);
-  }
-
-  external static List<int> _encodeString(String string);
-}
-
-
-class _StringEncoders {
-  static _StringEncoder encoder(Encoding encoding) {
-    if (encoding == Encoding.UTF_8) {
-      return new _UTF8Encoder();
-    } else if (encoding == Encoding.ISO_8859_1) {
-      return new _Latin1Encoder();
-    } else if (encoding == Encoding.ASCII) {
-      return new _AsciiEncoder();
-    } else if (encoding == Encoding.SYSTEM) {
-      if (Platform.operatingSystem == 'windows') {
-        return new _WindowsCodePageEncoder();
-      }
-      return new _UTF8Encoder();
-    } else {
-      throw new StreamException("Unsupported encoding ${encoding.name}");
-    }
-  }
-}
-
-
-class EncoderException implements Exception {
-  const EncoderException([String this.message]);
-  String toString() => "EncoderException: $message";
-  final String message;
-}
-
-
-class _StringInputStream implements StringInputStream {
-  _StringInputStream(InputStream this._input, Encoding this._encoding) {
-    _decoder = _StringDecoders.decoder(encoding);
-    _input.onData = _onData;
-    _input.onClosed = _onClosed;
-  }
-
-  String read([int len]) {
-    String result = _decoder.decoded(len);
-    _checkInstallDataHandler();
-    return result;
-  }
-
-  String readLine() {
-    String decodedLine = _decoder.decodedLine;
-    if (decodedLine == null) {
-      if (_inputClosed) {
-        // Last line might not have a line separator.
-        decodedLine = _decoder.decoded();
-        if (decodedLine != null &&
-            decodedLine[decodedLine.length - 1] == '\r') {
-          decodedLine = decodedLine.substring(0, decodedLine.length - 1);
-        }
-      }
-    }
-    _checkInstallDataHandler();
-    return decodedLine;
-  }
-
-  int available() => _decoder.available();
-
-  Encoding get encoding => _encoding;
-
-  bool get closed => _inputClosed && _decoder.isEmpty;
-
-  void set onData(void callback()) {
-    _clientDataHandler = callback;
-    _clientLineHandler = null;
-    _checkInstallDataHandler();
-    _checkScheduleCallback();
-  }
-
-  void set onLine(void callback()) {
-    _clientLineHandler = callback;
-    _clientDataHandler = null;
-    _checkInstallDataHandler();
-    _checkScheduleCallback();
-  }
-
-  void set onClosed(void callback()) {
-    _clientCloseHandler = callback;
-  }
-
-  void set onError(void callback(e)) {
-    _input.onError = callback;
-    _decoder.onError = (e) {
-      _clientCloseHandler = null;
-      _input.close();
-      callback(e);
-    };
-  }
-
-  void _onData() {
-    _readData();
-    if (!_decoder.isEmpty && _clientDataHandler != null) {
-      _clientDataHandler();
-    }
-    if (_decoder.lineBreaks > 0 && _clientLineHandler != null) {
-      _clientLineHandler();
-    }
-    _checkScheduleCallback();
-    _checkInstallDataHandler();
-  }
-
-  void _onClosed() {
-    _inputClosed = true;
-    _decoder.done();
-    if (_decoder.isEmpty && _clientCloseHandler !=  null) {
-      _clientCloseHandler();
-    } else {
-      _checkScheduleCallback();
-    }
-  }
-
-  void _readData() {
-    List<int> data = _input.read();
-    if (data != null) {
-      _decoder.write(data);
-    }
-  }
-
-  void _checkInstallDataHandler() {
-    if (_inputClosed ||
-        (_clientDataHandler == null && _clientLineHandler == null)) {
-      _input.onData = null;
-    } else if (_clientDataHandler != null) {
-      if (_decoder.isEmpty) {
-        _input.onData = _onData;
-      } else {
-        _input.onData = null;
-      }
-    } else {
-      assert(_clientLineHandler != null);
-      if (_decoder.lineBreaks == 0) {
-        _input.onData = _onData;
-      } else {
-        _input.onData = null;
-      }
-    }
-  }
-
-  // TODO(sgjesse): Find a better way of scheduling callbacks from
-  // the event loop.
-  void _checkScheduleCallback() {
-    void issueDataCallback() {
-      _scheduledDataCallback = null;
-      if (_clientDataHandler != null) {
-        _clientDataHandler();
-        _checkScheduleCallback();
-      }
-    }
-
-    void issueLineCallback() {
-      _scheduledLineCallback = null;
-      if (_clientLineHandler != null) {
-        _clientLineHandler();
-        _checkScheduleCallback();
-      }
-    }
-
-    void issueCloseCallback() {
-      _scheduledCloseCallback = null;
-      if (!_closed) {
-        if (_clientCloseHandler != null) _clientCloseHandler();
-        _closed = true;
-      }
-    }
-
-    if (!_closed) {
-      // Schedule data callback if string data available.
-      if (_clientDataHandler != null &&
-          !_decoder.isEmpty &&
-          _scheduledDataCallback == null) {
-        if (_scheduledLineCallback != null) {
-          _scheduledLineCallback.cancel();
-        }
-        _scheduledDataCallback = Timer.run(issueDataCallback);
-      }
-
-      // Schedule line callback if a line is available.
-      if (_clientLineHandler != null &&
-          (_decoder.lineBreaks > 0 || (!_decoder.isEmpty && _inputClosed)) &&
-          _scheduledLineCallback == null) {
-        if (_scheduledDataCallback != null) {
-          _scheduledDataCallback.cancel();
-        }
-        _scheduledLineCallback = Timer.run(issueLineCallback);
-      }
-
-      // Schedule close callback if no more data and input is closed.
-      if (_decoder.isEmpty &&
-          _inputClosed &&
-          _scheduledCloseCallback == null) {
-        _scheduledCloseCallback = Timer.run(issueCloseCallback);
-      }
-    }
-  }
-
-  InputStream _input;
-  Encoding _encoding;
-  _StringDecoder _decoder;
-  bool _inputClosed = false;  // Is the underlying input stream closed?
-  bool _closed = false;  // Is this stream closed.
-  bool _eof = false;  // Has all data been read from the decoder?
-  Timer _scheduledDataCallback;
-  Timer _scheduledLineCallback;
-  Timer _scheduledCloseCallback;
-  Function _clientDataHandler;
-  Function _clientLineHandler;
-  Function _clientCloseHandler;
-}