Move image loading out of C++ into Dart

We already know how to talk to the network_service from Dart
via fetch.dart.  Might as well use that for Image loading
as well insetad of having ImageLoader do it.

As part of this I've renamed *ImageLoader to *ImageDecoder
and moved all the image loading logic into Dart.  This required
me to teach the idl system about mojo handles so that I could
pass the resulting MojoHandle from fetch.dart up through to
ImageDecoder.

R=abarth@chromium.org, jackson@google.com, hansmuller@google.com

Review URL: https://codereview.chromium.org/1173703002.

engine/bindings/scripts/dart_methods.py

@@ -154,6 +154,10 @@ def cpp_value(interface, method, number_of_arguments):
         if idl_type.is_typed_array_type:
             return '%s.get()' % argument_name
 
+        # TODO(eseidel): This should check cpp_type.endswith('Handle')
+        if idl_type.name == 'MojoDataPipeConsumer':
+            return '%s.Pass()' % argument_name
+
         if idl_type.name == 'EventListener':
             if (interface.name == 'EventTarget' and
                 method.name == 'removeEventListener'):
@@ -161,9 +165,7 @@ def cpp_value(interface, method, number_of_arguments):
                 # EventTarget::removeEventListener
                 return '%s.get()' % argument_name
             return argument.name
-        if (idl_type.is_callback_interface or
-            idl_type.name in ['NodeFilter', 'XPathNSResolver']):
-            # FIXME: remove this special case
+        if idl_type.is_callback_interface:
             return '%s.release()' % argument_name
         return argument_name
 

engine/bindings/scripts/dart_types.py

@@ -116,9 +116,13 @@ CPP_SPECIAL_CONVERSION_RULES = {
     'unrestricted float': 'float',
     # Pass these by value, not pointer.
     'Color': 'SkColor',
+    # These direct conversions appear to be working around
+    # dart_value_to_cpp_value using CPP_SPECIAL_CONVERSION_RULES directly
+    # instead of calling cpp_type.
     'Float32List': 'Float32List',
     'Point': 'Point',
     'Rect': 'Rect',
+    'MojoDataPipeConsumer': 'mojo::ScopedDataPipeConsumerHandle',
     'TransferMode': 'SkXfermode::Mode',
     'PaintingStyle': 'SkPaint::Style',
 }
@@ -256,6 +260,7 @@ INCLUDES_FOR_TYPE = {
     'NodeList': set(['sky/engine/core/dom/NodeList.h',
                      'sky/engine/core/dom/StaticNodeList.h']),
     'DartValue': set(['sky/engine/tonic/dart_value.h']),
+    'MojoDataPipeConsumer': set(['sky/engine/tonic/mojo_converter.h']),
 }
 
 
@@ -370,6 +375,7 @@ DART_TO_CPP_VALUE = {
     'Rect': pass_by_value_format('Rect'),
     'TransferMode': pass_by_value_format('TransferMode'),
     'PaintingStyle': pass_by_value_format('PaintingStyle'),
+    'MojoDataPipeConsumer': pass_by_value_format('mojo::ScopedDataPipeConsumerHandle'),
 }
 
 def dart_value_to_cpp_value(idl_type, extended_attributes, variable_name,
@@ -512,6 +518,7 @@ IDL_TO_DART_TYPE = {
     'boolean': 'bool',
     'void': 'void',
     'unsigned long': 'int',
+    'MojoDataPipeConsumer': 'int',
 }
 
 def idl_type_to_dart_type(idl_type):

engine/core/core.gni

@@ -798,8 +798,8 @@ sky_core_files = [
   "inspector/ScriptAsyncCallStack.h",
   "inspector/ScriptGCEventListener.h",
   "layout/LayoutCallback.h",
-  "loader/CanvasImageLoader.cpp",
-  "loader/CanvasImageLoader.h",
+  "loader/CanvasImageDecoder.cpp",
+  "loader/CanvasImageDecoder.h",
   "loader/DocumentLoadTiming.cpp",
   "loader/DocumentLoadTiming.h",
   "loader/EmptyClients.cpp",
@@ -812,7 +812,7 @@ sky_core_files = [
   "loader/FrameLoaderTypes.h",
   "loader/ImageLoader.cpp",
   "loader/ImageLoader.h",
-  "loader/ImageLoaderCallback.h",
+  "loader/ImageDecoderCallback.h",
   "loader/MojoLoader.cpp",
   "loader/MojoLoader.h",
   "loader/NavigationPolicy.h",
@@ -1142,8 +1142,8 @@ core_idl_files = get_path_info([
                                  "html/TextMetrics.idl",
                                  "html/VoidCallback.idl",
                                  "layout/LayoutCallback.idl",
-                                 "loader/ImageLoader.idl",
-                                 "loader/ImageLoaderCallback.idl",
+                                 "loader/ImageDecoder.idl",
+                                 "loader/ImageDecoderCallback.idl",
                                  "painting/Canvas.idl",
                                  "painting/ColorFilter.idl",
                                  "painting/DrawLooper.idl",

engine/core/loader/CanvasImageLoader.cpp → engine/core/loader/CanvasImageDecoder.cpp

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "sky/engine/config.h"
-#include "sky/engine/core/loader/CanvasImageLoader.h"
+#include "sky/engine/core/loader/CanvasImageDecoder.h"
 #include "sky/engine/core/painting/CanvasImage.h"
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/platform/SharedBuffer.h"
@@ -11,30 +11,27 @@
 
 namespace blink {
 
-CanvasImageLoader::CanvasImageLoader(const String& src, PassOwnPtr<ImageLoaderCallback> callback)
-  : callback_(callback) {
-  KURL url = KURL(DOMDartState::Current()->url(), src);
-  fetcher_ = adoptPtr(new MojoFetcher(this, url));
+PassRefPtr<CanvasImageDecoder> CanvasImageDecoder::create(
+  mojo::ScopedDataPipeConsumerHandle handle,
+  PassOwnPtr<ImageDecoderCallback> callback)
+{
+  return adoptRef(new CanvasImageDecoder(handle.Pass(), callback));
 }
 
-CanvasImageLoader::~CanvasImageLoader() {
+CanvasImageDecoder::CanvasImageDecoder(mojo::ScopedDataPipeConsumerHandle handle, PassOwnPtr<ImageDecoderCallback> callback)
+  : callback_(callback) {
+  buffer_ = SharedBuffer::create();
+  drainer_ = adoptPtr(new mojo::common::DataPipeDrainer(this, handle.Pass()));
 }
 
-void CanvasImageLoader::OnReceivedResponse(mojo::URLResponsePtr response) {
-  if (response->status_code != 200) {
-    callback_->handleEvent(nullptr);
-    return;
-  }
-  buffer_ = SharedBuffer::create();
-  drainer_ =
-      adoptPtr(new mojo::common::DataPipeDrainer(this, response->body.Pass()));
+CanvasImageDecoder::~CanvasImageDecoder() {
 }
 
-void CanvasImageLoader::OnDataAvailable(const void* data, size_t num_bytes) {
+void CanvasImageDecoder::OnDataAvailable(const void* data, size_t num_bytes) {
   buffer_->append(static_cast<const char*>(data), num_bytes);
 }
 
-void CanvasImageLoader::OnDataComplete() {
+void CanvasImageDecoder::OnDataComplete() {
   OwnPtr<ImageDecoder> decoder =
       ImageDecoder::create(*buffer_.get(), ImageSource::AlphaPremultiplied,
                            ImageSource::GammaAndColorProfileIgnored);

engine/core/loader/CanvasImageLoader.h → engine/core/loader/CanvasImageDecoder.h

@@ -7,41 +7,32 @@
 #define SKY_ENGINE_CORE_LOADER_CANVASIMAGELOADER_H_
 
 #include "mojo/common/data_pipe_drainer.h"
-#include "sky/engine/core/loader/ImageLoaderCallback.h"
+#include "sky/engine/core/loader/ImageDecoderCallback.h"
 #include "sky/engine/platform/SharedBuffer.h"
-#include "sky/engine/platform/fetcher/MojoFetcher.h"
 #include "sky/engine/tonic/dart_wrappable.h"
 #include "sky/engine/wtf/OwnPtr.h"
 #include "sky/engine/wtf/text/AtomicString.h"
 
 namespace blink {
 
-class CanvasImageLoader : public MojoFetcher::Client,
-                          public mojo::common::DataPipeDrainer::Client,
-                          public RefCounted<CanvasImageLoader>,
-                          public DartWrappable {
+class CanvasImageDecoder : public mojo::common::DataPipeDrainer::Client,
+                           public RefCounted<CanvasImageDecoder>,
+                           public DartWrappable {
   DEFINE_WRAPPERTYPEINFO();
  public:
-  static PassRefPtr<CanvasImageLoader> create(const String& src, PassOwnPtr<ImageLoaderCallback> callback)
-  {
-    return adoptRef(new CanvasImageLoader(src, callback));
-  }
-  virtual ~CanvasImageLoader();
-
-  // MojoFetcher::Client
-  void OnReceivedResponse(mojo::URLResponsePtr) override;
+  static PassRefPtr<CanvasImageDecoder> create(mojo::ScopedDataPipeConsumerHandle handle, PassOwnPtr<ImageDecoderCallback> callback);
+  virtual ~CanvasImageDecoder();
 
   // mojo::common::DataPipeDrainer::Client
   void OnDataAvailable(const void*, size_t) override;
   void OnDataComplete() override;
 
  private:
-  explicit CanvasImageLoader(const String& src, PassOwnPtr<ImageLoaderCallback> callback);
+  CanvasImageDecoder(mojo::ScopedDataPipeConsumerHandle handle, PassOwnPtr<ImageDecoderCallback> callback);
 
-  OwnPtr<MojoFetcher> fetcher_;
   OwnPtr<mojo::common::DataPipeDrainer> drainer_;
   RefPtr<SharedBuffer> buffer_;
-  OwnPtr<ImageLoaderCallback> callback_;
+  OwnPtr<ImageDecoderCallback> callback_;
 };
 
 }  // namespace blink

engine/core/loader/ImageLoader.idl → engine/core/loader/ImageDecoder.idl

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 [
-  Constructor(DOMString src, ImageLoaderCallback callback),
-  ImplementedAs=CanvasImageLoader,
-] interface ImageLoader {
+  Constructor(MojoDataPipeConsumer consumer, ImageDecoderCallback callback),
+  ImplementedAs=CanvasImageDecoder,
+] interface ImageDecoder {
 };

engine/core/loader/ImageLoaderCallback.h → engine/core/loader/ImageDecoderCallback.h

@@ -9,9 +9,9 @@
 
 namespace blink {
 
-class ImageLoaderCallback {
+class ImageDecoderCallback {
 public:
-    virtual ~ImageLoaderCallback() {}
+    virtual ~ImageDecoderCallback() {}
     virtual void handleEvent(CanvasImage* result) = 0;
 };
 

engine/core/loader/ImageLoaderCallback.idl → engine/core/loader/ImageDecoderCallback.idl

@@ -2,6 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-callback interface ImageLoaderCallback {
+callback interface ImageDecoderCallback {
     void handleEvent(Image result);
 };

engine/tonic/mojo_converter.h

@@ -25,6 +25,20 @@ struct DartConverter<mojo::ScopedHandleBase<HandleType>> {
   static Dart_Handle ToDart(mojo::ScopedHandleBase<HandleType> mojo_handle) {
     return Dart_NewInteger(static_cast<int64_t>(mojo_handle.release().value()));
   }
+
+  static mojo::ScopedHandleBase<HandleType> FromArgumentsWithNullCheck(
+      Dart_NativeArguments args,
+      int index,
+      Dart_Handle& exception,
+      bool auto_scope = true) {
+    int64_t mojo_handle64 = 0;
+    Dart_Handle result = Dart_GetNativeIntegerArgument(args, index, &mojo_handle64);
+    if (Dart_IsError(result) || !mojo_handle64)
+      return mojo::ScopedHandleBase<HandleType>();
+
+    HandleType mojo_handle(static_cast<MojoHandle>(mojo_handle64));
+    return mojo::MakeScopedHandle(mojo_handle);
+  }
 };
 
 }  // namespace blink

examples/stocks/lib/stock_data.dart

@@ -59,7 +59,7 @@ class StockDataFetcher {
   }
 
   void _fetchNextChunk() {
-    fetch('data/stock_data_${_currentChunk++}.json').then((Response response) {
+    fetchBody('data/stock_data_${_currentChunk++}.json').then((Response response) {
       String json = response.bodyAsString();
       JsonDecoder decoder = new JsonDecoder();
 

examples/stocks2/lib/stock_data.dart

@@ -59,7 +59,7 @@ class StockDataFetcher {
   }
 
   void _fetchNextChunk() {
-    fetch('../data/stock_data_${_currentChunk++}.json').then((Response response) {
+    fetchBody('../data/stock_data_${_currentChunk++}.json').then((Response response) {
       String json = response.bodyAsString();
       JsonDecoder decoder = new JsonDecoder();
 

sdk/README.md

@@ -109,7 +109,7 @@ ergonomic interface:
 import 'package:sky/framework/net/fetch.dart';
 
 main() async {
-  Response response = await fetch('example.txt');
+  Response response = await fetchBody('example.txt');
   print(response.bodyAsString());
 }
 ```

sdk/lib/framework/net/fetch.dart

@@ -9,6 +9,7 @@ import 'package:mojo/core.dart' as core;
 import 'package:mojom/mojo/network_service.mojom.dart';
 import 'package:mojom/mojo/url_loader.mojom.dart';
 import 'package:mojom/mojo/url_request.mojom.dart';
+import 'package:mojom/mojo/url_response.mojom.dart';
 
 class Response {
   ByteData body;
@@ -20,23 +21,30 @@ class Response {
   }
 }
 
-Future<Response> fetch(String relativeUrl) async {
-  String url = Uri.base.resolve(relativeUrl).toString();
-
-  var net = new NetworkServiceProxy.unbound();
+Future<UrlResponse> fetch(UrlRequest request) async {
+  NetworkServiceProxy net = new NetworkServiceProxy.unbound();
   shell.requestService("mojo:authenticated_network_service", net);
 
-  var loader = new UrlLoaderProxy.unbound();
+  UrlLoaderProxy loader = new UrlLoaderProxy.unbound();
   net.ptr.createUrlLoader(loader);
 
-  var request = new UrlRequest()
-    ..url = url
-    ..autoFollowRedirects = true;
-  var response = (await loader.ptr.start(request)).response;
+  UrlResponse response = (await loader.ptr.start(request)).response;
 
   loader.close();
   net.close();
+  return response;
+}
+
+Future<UrlResponse> fetchUrl(String relativeUrl) async {
+  String url = Uri.base.resolve(relativeUrl).toString();
+  UrlRequest request = new UrlRequest()
+    ..url = url
+    ..autoFollowRedirects = true;
+  return fetch(request);
+}
 
+Future<Response> fetchBody(String relativeUrl) async {
+  UrlResponse response = await fetchMojo(relativeUrl);
   if (response.body == null) return new Response(null);
 
   ByteData data = await core.DataPipeDrainer.drainHandle(response.body);

sdk/lib/framework/net/image_cache.dart

@@ -2,17 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:sky' as sky;
+import 'dart:sky';
 import 'dart:collection';
+import 'fetch.dart';
+import 'package:mojom/mojo/url_response.mojom.dart';
 
-final HashMap<String, List<sky.ImageLoaderCallback>> _pendingRequests =
-  new HashMap<String, List<sky.ImageLoaderCallback>>();
+final HashMap<String, List<ImageDecoderCallback>> _pendingRequests =
+  new HashMap<String, List<ImageDecoderCallback>>();
 
-final HashMap<String, sky.Image> _completedRequests =
-  new HashMap<String, sky.Image>();
+final HashMap<String, Image> _completedRequests =
+  new HashMap<String, Image>();
 
-void load(String url, sky.ImageLoaderCallback callback) {
-  sky.Image result = _completedRequests[url];
+void load(String url, ImageDecoderCallback callback) {
+  Image result = _completedRequests[url];
   if (result != null) {
     callback(_completedRequests[url]);
     return;
@@ -21,13 +23,15 @@ void load(String url, sky.ImageLoaderCallback callback) {
   bool newRequest = false;
   _pendingRequests.putIfAbsent(url, () {
     newRequest = true;
-    return new List<sky.ImageLoaderCallback>();
+    return new List<ImageDecoderCallback>();
   }).add(callback);
   if (newRequest) {
-    new sky.ImageLoader(url, (image) {
-      _completedRequests[url] = image;
-      _pendingRequests[url].forEach((c) => c(image));
-      _pendingRequests.remove(url);
+    fetchUrl(url).then((UrlResponse response) {
+      new ImageDecoder(response.body.handle.h, (image) {
+        _completedRequests[url] = image;
+        _pendingRequests[url].forEach((c) => c(image));
+        _pendingRequests.remove(url);
+      });
     });
   }
 }