Add chunked conversion to converters.

sdk/lib/convert/converter.dart

Index: sdk/lib/convert/converter.dart
diff --git a/sdk/lib/convert/converter.dart b/sdk/lib/convert/converter.dart
index 8e7a6f164f9a5b8aae3319d3b58ca15456a53f8d..43106c6a7d5c8050055b7cce665d63970f48e484 100644
--- a/sdk/lib/convert/converter.dart
+++ b/sdk/lib/convert/converter.dart
@@ -25,6 +25,32 @@ abstract class Converter<S, T> {
   Converter<S, dynamic> fuse(Converter<T, dynamic> other) {
     return new _FusedConverter<S, T, dynamic>(this, other);
   }
+
+  /**
+   * Starts a chunked conversion.
+   *
+   * The returned [ChunkedConversionSink] supports the interface described by
+   * [inputInterface].
+   *
+   * If the given [sink] supports the methods described by
+   * [outputInterface] then the chunked conversion can take advantage of
+   * the additional methods and provide a more efficient conversion.
+   *
+   * If [sink] does not support the [outputInterface] it is adapted. If
+   * necessary, the adapter buffers all chunks and invokes
+   * `addNonChunked` on [sink].
+   */
+  ChunkedConversionSink<S, dynamic> startChunkedConversion(

[Søren Gjesse, 2013/07/24 09:26:41]

How about just calling this something shorter? Maybe just start.

[floitsch, 2013/07/24 18:31:15]

I'm torn...
Will discuss with others to get a feeling.

+      ChunkedConversionSink sink) {
+    return new _NonChunkedSink<S, T>(this, sink.adaptTo(outputInterface));
+  }
+
+  /** Defines the accepted input interface for chunked conversions. */
+  ChunkedConversionInterface get inputInterface =>
+      ChunkedConversionSink.INTERFACE;
+  /** Defines the accepted output interface for chunked conversions. */
+  ChunkedConversionInterface get outputInterface =>
+      ChunkedConversionSink.INTERFACE;
 }
 
 /**
@@ -39,4 +65,12 @@ class _FusedConverter<S, M, T> extends Converter<S, T> {
   _FusedConverter(this._first, this._second);
 
   T convert(S input) => _second.convert(_first.convert(input));
+
+  ChunkedConversionSink<S, dynamic> startChunkedConversion(
+      ChunkedConversionSink sink) {
+    return _first.startChunkedConversion(_second.startChunkedConversion(sink));
+  }
+
+  ChunkedConversionInterface get inputInterface => _first.inputInterface;
+  ChunkedConversionInterface get outputInterface => _second.outputInterface;
 }