Shapedetection module: Blink side implementation

third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp

Index: third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
diff --git a/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp b/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
index 9f7100f852d2c4b2cae09b6e5dcec0929f0eeca3..42f954a481e8a3d66d27444f499d8a39653ca59d 100644
--- a/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
+++ b/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
@@ -4,22 +4,128 @@
 
 #include "modules/shapedetection/FaceDetector.h"
 
-#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
+#include "core/dom/DOMRect.h"
+#include "core/dom/Document.h"
+#include "core/fetch/ImageResource.h"
+#include "core/frame/LocalFrame.h"
+#include "core/html/HTMLImageElement.h"
+#include "platform/graphics/Image.h"
+#include "public/platform/InterfaceProvider.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/core/SkImageInfo.h"
 
 namespace blink {
 
-FaceDetector* FaceDetector::create()
+namespace {
+
+mojo::ScopedSharedBufferHandle getSharedBufferHandle(const HTMLImageElement* img)
+{
+    ImageResource* imgResource = img->cachedImage();

[mcasas, 2016/09/30 02:14:59]

ImageResource* const ?

[xianglu, 2016/09/30 16:37:41]

Done.

+    if (!imgResource) {
+        DLOG(ERROR) << "Failed to convert HTMLImageElement to ImageSource.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    Image* blinkImage = imgResource->getImage();

[mcasas, 2016/09/30 02:14:59]

Image* const ?

[xianglu, 2016/09/30 16:37:41]

Done.

+    if (!blinkImage) {
+        DLOG(ERROR) << "Failed to convert ImageSource to blink::Image.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    sk_sp<SkImage> skImg = blinkImage->imageForCurrentFrame();

[mcasas, 2016/09/30 02:14:59]

const sk_sp<SkImage> skiaImage ?

[xianglu, 2016/09/30 16:37:40]

Done.

+    if (!skImg) {
+        DLOG(ERROR) << "Failed to convert blink::Image to sk_sp<SkImage>.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    SkImageInfo dstInfo = SkImageInfo::MakeN32(skImg->width(), skImg->height(), skImg->alphaType());

[mcasas, 2016/09/30 02:14:59]

const SkImageInfo skiaInfo ?

[xianglu, 2016/09/30 16:37:41]

Done.

+
+    uint32_t allocationSize = dstInfo.getSafeSize(dstInfo.minRowBytes());

[mcasas, 2016/09/30 02:14:59]

const 

[xianglu, 2016/09/30 16:37:41]

Done.

+    mojo::ScopedSharedBufferHandle sharedBufferHandle = mojo::SharedBufferHandle::Create(allocationSize);
+    mojo::ScopedSharedBufferMapping mappingPtr = sharedBufferHandle->Map(allocationSize);
+    DCHECK(mappingPtr);
+
+    SkPixmap pixmap(dstInfo, mappingPtr.get(), dstInfo.minRowBytes());

[mcasas, 2016/09/30 02:14:59]

const 

[xianglu, 2016/09/30 16:37:41]

Done.

+    if (!skImg->readPixels(pixmap, 0, 0)) {
+        DLOG(ERROR) << "Failed to read pixels from sk_sp<SkImage>.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    DCHECK_EQ(img->naturalWidth(), skImg->width());
+    DCHECK_EQ(img->naturalHeight(), skImg->height());

[mcasas, 2016/09/30 02:14:59]

Move these two contracts/preconditions to l.37,
i.e. as close as possible to |skImage| declaration
as possible.

[xianglu, 2016/09/30 16:37:40]

Done.

+    return sharedBufferHandle;
+}
+
+} // anonymous namespace
+
+FaceDetector* FaceDetector::create(const Document& document)
+{
+    return new FaceDetector(*document.frame());
+}
+
+FaceDetector::FaceDetector(LocalFrame& frame)
 {
-    return new FaceDetector();
+    DCHECK(!m_service.is_bound());
+    DCHECK(frame.interfaceProvider());
+    frame.interfaceProvider()->getInterface(mojo::GetProxy(&m_service));
 }
 
-ScriptPromise FaceDetector::detect(ScriptState* scriptState, const HTMLImageElement* image)
+ScriptPromise FaceDetector::detect(ScriptState* scriptState, const HTMLImageElement* img)
 {
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
-    resolver->reject(DOMException::create(NotSupportedError, "Not implemented"));
+
+    if (!m_service) {
+        resolver->reject(DOMException::create(NotFoundError, "Face detection service unavailable."));
+        return promise;
+    }
+
+    if (!img) {
+        resolver->reject(DOMException::create(SyntaxError, "The provided HTMLImageElement is empty."));
+        return promise;
+    }
+
+    // TODO(xianglu): Add security check when the spec is ready. https://crbug.com/646083
+    mojo::ScopedSharedBufferHandle sharedBufferHandle = getSharedBufferHandle(img);
+    if (!sharedBufferHandle->is_valid()) {
+        resolver->reject(DOMException::create(SyntaxError, "Failed to get sharedBufferHandle."));
+        return promise;
+    }
+
+    m_serviceRequests.add(resolver);
+    DCHECK(m_service.is_bound());
+    m_service->DetectFace(
+        std::move(sharedBufferHandle),
+        img->naturalWidth(), img->naturalHeight(),

[mcasas, 2016/09/30 02:14:59]

Strange indenting: either all parameters are in the
same line, or these two should go on different lines.
Should be easier to solve after Friday when Blink
style converges to Cr style though.

[xianglu, 2016/09/30 16:37:41]

Done.

+        convertToBaseCallback(WTF::bind(&FaceDetector::onDetectFace, wrapPersistent(this), wrapPersistent(resolver)))
+        );
+    sharedBufferHandle.reset();
     return promise;
 }
 
+
+void FaceDetector::onDetectFace(ScriptPromiseResolver* resolver, mojo::WTFArray<mojom::blink::BoundingBoxPtr> boundingBoxes)
+{
+    if (!m_serviceRequests.contains(resolver))
+        return;
+
+    HeapVector<Member<DOMRect>> resultRects;
+    for (size_t i = 0; i < boundingBoxes.size(); i++) {
+        resultRects.append(DOMRect::create(
+            boundingBoxes.at(i)->x,
+            boundingBoxes.at(i)->y,
+            boundingBoxes.at(i)->width,
+            boundingBoxes.at(i)->height));
+    }

[mcasas, 2016/09/30 02:14:59]

Consider for-range loop and const auto&: 

    HeapVector<Member<DOMRect>> detectedFaces;
    for (const auto& boundingBox : boundingBoxes) {
        detectedFaces.append(DOMRect::create(boundingBox.x, boundingBox.y,
boundingBox.width, boundingBox.height));
    }

[xianglu, 2016/09/30 16:37:41]

There is no begin() function in mojo::WTFArray.

+
+    resolver->resolve(resultRects);
+    m_serviceRequests.remove(resolver);
+}
+
+DEFINE_TRACE(FaceDetector)
+{
+    visitor->trace(m_serviceRequests);
+}
+
 } // namespace blink