unfork DDC's copy of most SDK libraries

pkg/dev_compiler/tool/input_sdk/lib/convert/byte_conversion.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.convert;
-
-/**
- * The [ByteConversionSink] provides an interface for converters to
- * efficiently transmit byte data.
- *
- * Instead of limiting the interface to one non-chunked list of bytes it
- * accepts its input in chunks (themselves being lists of bytes).
- *
- * This abstract class will likely get more methods over time. Implementers are
- * urged to extend or mix in [ByteConversionSinkBase] to ensure that their
- * class covers the newly added methods.
- */
-abstract class ByteConversionSink extends ChunkedConversionSink<List<int>> {
-  ByteConversionSink();
-  factory ByteConversionSink.withCallback(void callback(List<int> accumulated))
-      = _ByteCallbackSink;
-  factory ByteConversionSink.from(Sink<List<int>> sink)
-      = _ByteAdapterSink;
-
-  /**
-   * Adds the next [chunk] to `this`.
-   *
-   * Adds the bytes defined by [start] and [end]-exclusive to `this`.
-   *
-   * If [isLast] is `true` closes `this`.
-   *
-   * Contrary to `add` the given [chunk] must not be held onto. Once the method
-   * returns, it is safe to overwrite the data in it.
-   */
-  void addSlice(List<int> chunk, int start, int end, bool isLast);
-
-  // TODO(floitsch): add more methods:
-  // - iterateBytes.
-}
-
-/**
- * This class provides a base-class for converters that need to accept byte
- * inputs.
- */
-abstract class ByteConversionSinkBase extends ByteConversionSink {
-
-  void add(List<int> chunk);
-  void close();
-
-  void addSlice(List<int> chunk, int start, int end, bool isLast) {
-    add(chunk.sublist(start, end));
-    if (isLast) close();
-  }
-}
-
-/**
- * This class adapts a simple [Sink] to a [ByteConversionSink].
- *
- * All additional methods of the [ByteConversionSink] (compared to the
- * ChunkedConversionSink) are redirected to the `add` method.
- */
-class _ByteAdapterSink extends ByteConversionSinkBase {
-  final Sink<List<int>> _sink;
-
-  _ByteAdapterSink(this._sink);
-
-  void add(List<int> chunk) { _sink.add(chunk); }
-  void close() { _sink.close(); }
-}
-
-/**
- * This class accumulates all chunks into one list of bytes
- * and invokes a callback when the sink is closed.
- *
- * This class can be used to terminate a chunked conversion.
- */
-class _ByteCallbackSink extends ByteConversionSinkBase {
-  static const _INITIAL_BUFFER_SIZE = 1024;
-
-  final _ChunkedConversionCallback<List<int>> _callback;
-  List<int> _buffer = new Uint8List(_INITIAL_BUFFER_SIZE);
-  int _bufferIndex = 0;
-
-  _ByteCallbackSink(void callback(List<int> accumulated))
-      : this._callback = callback;
-
-  void add(Iterable<int> chunk) {
-    int freeCount = _buffer.length - _bufferIndex;
-    if (chunk.length > freeCount) {
-      // Grow the buffer.
-      int oldLength = _buffer.length;
-      int newLength = _roundToPowerOf2(chunk.length + oldLength) * 2;
-      List<int> grown = new Uint8List(newLength);
-      grown.setRange(0, _buffer.length, _buffer);
-      _buffer = grown;
-    }
-    _buffer.setRange(_bufferIndex, _bufferIndex + chunk.length, chunk);
-    _bufferIndex += chunk.length;
-  }
-
-  static int _roundToPowerOf2(int v) {
-    assert(v > 0);
-    v--;
-    v |= v >> 1;
-    v |= v >> 2;
-    v |= v >> 4;
-    v |= v >> 8;
-    v |= v >> 16;
-    v++;
-    return v;
-  }
-
-  void close() {
-    _callback(_buffer.sublist(0, _bufferIndex));
-  }
-}