Revert accidental parts of "Speed up toLowerCase, by manually inlining the upper-case part."

sdk/lib/io/io_sink.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;
 
 /**
  * Helper class to wrap a [StreamConsumer<List<int>>] and provide
  * utility functions for writing to the StreamConsumer directly. The
  * [IOSink] buffers the input given by all [StringSink] methods and will delay
  * an [addStream] until the buffer is flushed.
  *
  * When the [IOSink] is bound to a stream (through [addStream]) any call
  * to the [IOSink] will throw a [StateError]. When the [addStream] completes,
- * the [IOSink] will again accept all method calls.
+ * the [IOSink] will again be open for all calls.
  *
  * If data is added to the [IOSink] after the sink is closed, the data will be
  * ignored. Use the [done] future to be notified when the [IOSink] is closed.
  */
 abstract class IOSink implements StreamSink<List<int>>, StringSink {
   // TODO(ajohnsen): Make _encodingMutable an argument.
   factory IOSink(StreamConsumer<List<int>> target,
                  {Encoding encoding: UTF8})
       => new _IOSinkImpl(target, encoding);
 
@@ skipping 91 matching lines @@
   Future close();
 
   /**
    * Get a future that will complete when the consumer closes, or when an
    * error occurs. This future is identical to the future returned by
    * [close].
    */
   Future get done;
 }
 
+class _StreamSinkImpl<T> implements StreamSink<T> {
+  final StreamConsumer<T> _target;
+  Completer _doneCompleter = new Completer();
+  Future _doneFuture;
+  StreamController<T> _controllerInstance;
+  Completer _controllerCompleter;
+  bool _isClosed = false;
+  bool _isBound = false;
+  bool _hasError = false;
 
-class _IOSinkImpl extends StreamSinkAdapter<List<int>> implements IOSink {
+  _StreamSinkImpl(this._target) {
+    _doneFuture = _doneCompleter.future;
+  }
+
+  void add(T data) {
+    if (_isClosed) return;
+    _controller.add(data);
+  }
+
+  void addError(error, [StackTrace stackTrace]) =>
+      _controller.addError(error, stackTrace);
+
+  Future addStream(Stream<T> stream) {
+    if (_isBound) {
+      throw new StateError("StreamSink is already bound to a stream");
+    }
+    _isBound = true;
+    if (_hasError) return done;
+    // Wait for any sync operations to complete.
+    Future targetAddStream() {
+      return _target.addStream(stream)
+          .whenComplete(() {
+            _isBound = false;
+          });
+    }
+    if (_controllerInstance == null) return targetAddStream();
+    var future = _controllerCompleter.future;
+    _controllerInstance.close();
+    return future.then((_) => targetAddStream());
+  }
+
+  Future flush() {
+    if (_isBound) {
+      throw new StateError("StreamSink is bound to a stream");
+    }
+    if (_controllerInstance == null) return new Future.value(this);
+    // Adding an empty stream-controller will return a future that will complete
+    // when all data is done.
+    _isBound = true;
+    var future = _controllerCompleter.future;
+    _controllerInstance.close();
+    return future.whenComplete(() {
+          _isBound = false;
+        });
+  }
+
+  Future close() {
+    if (_isBound) {
+      throw new StateError("StreamSink is bound to a stream");
+    }
+    if (!_isClosed) {
+      _isClosed = true;
+      if (_controllerInstance != null) {
+        _controllerInstance.close();
+      } else {
+        _closeTarget();
+      }
+    }
+    return done;
+  }
+
+  void _closeTarget() {
+    _target.close()
+        .then((value) => _completeDone(value: value),
+              onError: (error) => _completeDone(error: error));
+  }
+
+  Future get done => _doneFuture;
+
+  void _completeDone({value, error}) {
+    if (_doneCompleter == null) return;
+    if (error == null) {
+      _doneCompleter.complete(value);
+    } else {
+      _hasError = true;
+      _doneCompleter.completeError(error);
+    }
+    _doneCompleter = null;
+  }
+
+  StreamController<T> get _controller {
+    if (_isBound) {
+      throw new StateError("StreamSink is bound to a stream");
+    }
+    if (_isClosed) {
+      throw new StateError("StreamSink is closed");
+    }
+    if (_controllerInstance == null) {
+      _controllerInstance = new StreamController<T>(sync: true);
+      _controllerCompleter = new Completer();
+      _target.addStream(_controller.stream)
+          .then(
+              (_) {
+                if (_isBound) {
+                  // A new stream takes over - forward values to that stream.
+                  _controllerCompleter.complete(this);
+                  _controllerCompleter = null;
+                  _controllerInstance = null;
+                } else {
+                  // No new stream, .close was called. Close _target.
+                  _closeTarget();
+                }
+              },
+              onError: (error) {
+                if (_isBound) {
+                  // A new stream takes over - forward errors to that stream.
+                  _controllerCompleter.completeError(error);
+                  _controllerCompleter = null;
+                  _controllerInstance = null;
+                } else {
+                  // No new stream. No need to close target, as it have already
+                  // failed.
+                  _completeDone(error: error);
+                }
+              });
+    }
+    return _controllerInstance;
+  }
+}
+
+
+class _IOSinkImpl extends _StreamSinkImpl<List<int>> implements IOSink {
   Encoding _encoding;
   bool _encodingMutable = true;
 
   _IOSinkImpl(StreamConsumer<List<int>> target, this._encoding)
       : super(target);
 
   Encoding get encoding => _encoding;
 
   void set encoding(Encoding value) {
     if (!_encodingMutable) {
@@ skipping 37 matching lines @@
 
   void writeln([Object obj = ""]) {
     write(obj);
     write("\n");
   }
 
   void writeCharCode(int charCode) {
     write(new String.fromCharCode(charCode));
   }
 }