Eliminate copies of encoded image data

third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h

Index: third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h
diff --git a/third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h b/third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h
index a177341eb26952ef934cffeeb18943f947fa3976..7852d995b4a17fa4ad3b94812540aadd74766f1c 100644
--- a/third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h
+++ b/third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h
@@ -27,7 +27,8 @@
 #define ImageFrameGenerator_h
 
 #include "platform/PlatformExport.h"
-#include "platform/graphics/ThreadSafeDataTransport.h"
+#include "platform/image-decoders/SegmentReader.h"
+#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkSize.h"
 #include "third_party/skia/include/core/SkTypes.h"
@@ -46,7 +47,6 @@ class SkData;
 namespace blink {
 
 class ImageDecoder;
-class SharedBuffer;
 
 class PLATFORM_EXPORT ImageDecoderFactory {
     USING_FAST_MALLOC(ImageDecoderFactory);
@@ -60,27 +60,21 @@ public:
 class PLATFORM_EXPORT ImageFrameGenerator final : public ThreadSafeRefCounted<ImageFrameGenerator> {
     WTF_MAKE_NONCOPYABLE(ImageFrameGenerator);
 public:
-    static PassRefPtr<ImageFrameGenerator> create(const SkISize& fullSize, PassRefPtr<SharedBuffer> data, bool allDataReceived, bool isMultiFrame = false)
+    static PassRefPtr<ImageFrameGenerator> create(const SkISize& fullSize, bool isMultiFrame = false)
     {
-        return adoptRef(new ImageFrameGenerator(fullSize, data, allDataReceived, isMultiFrame));
+        return adoptRef(new ImageFrameGenerator(fullSize, isMultiFrame));
     }
 
     ~ImageFrameGenerator();
 
-    void setData(PassRefPtr<SharedBuffer>, bool allDataReceived);
-
-    // Return our encoded image data. Caller takes ownership and must unref the data
-    // according to the contract SkImageGenerator::refEncodedData. Returns null if
-    // the data is has not been fully received.
-    SkData* refEncodedData();
-
     // Decodes and scales the specified frame at |index|. The dimensions and output
     // format are given in SkImageInfo. Decoded pixels are written into |pixels| with
     // a stride of |rowBytes|. Returns true if decoding was successful.
-    bool decodeAndScale(size_t index, const SkImageInfo&, void* pixels, size_t rowBytes);
+    bool decodeAndScale(SegmentReader*, bool allDataReceived, size_t index, const SkImageInfo&, void* pixels, size_t rowBytes);
 
     // Decodes YUV components directly into the provided memory planes.
-    bool decodeToYUV(size_t index, SkISize componentSizes[3], void* planes[3], size_t rowBytes[3]);
+    // Must not be called unless getYUVCompenentSizes has been called and returned true.

[Peter Kasting, 2016/03/23 02:42:58]

Nit: Component

[scroggo_chromium, 2016/03/24 13:59:45]

Done.

+    bool decodeToYUV(SegmentReader*, size_t index, SkISize componentSizes[3], void* planes[3], size_t rowBytes[3]);
 
     const SkISize& getFullSize() const { return m_fullSize; }
 
@@ -89,10 +83,12 @@ public:
 
     bool hasAlpha(size_t index);
 
-    bool getYUVComponentSizes(SkISize componentSizes[3]);
+    // Must not be called unless the SkROBuffer has all the data.
+    // FIXME: YUV decoding does not currently support progressive decoding.
+    bool getYUVComponentSizes(SegmentReader*, SkISize componentSizes[3]);
 
 private:
-    ImageFrameGenerator(const SkISize& fullSize, PassRefPtr<SharedBuffer>, bool allDataReceived, bool isMultiFrame);
+    ImageFrameGenerator(const SkISize& fullSize, bool isMultiFrame);
 
     friend class ImageFrameGeneratorTest;
     friend class DeferredImageDecoderTest;
@@ -101,26 +97,20 @@ private:
 
     void setHasAlpha(size_t index, bool hasAlpha);
 
-    // These methods are called while m_decodeMutex is locked.
-    SkBitmap tryToResumeDecode(size_t index, const SkISize& scaledSize);
-    bool decode(size_t index, ImageDecoder**, SkBitmap*);
-
-    SkISize m_fullSize;
+    // FIXME: Change the parameter to take an SkBitmap::Allocator, and no need for declaring this class.

[Peter Kasting, 2016/03/23 02:42:58]

Are you planning to do that in this CL?

[scroggo_chromium, 2016/03/24 13:59:45]

Done.

+    class ExternalMemoryAllocator;
+    SkBitmap tryToResumeDecode(SegmentReader*, bool allDataReceived, size_t index, const SkISize& scaledSize, ExternalMemoryAllocator*);
+    // This method is called while m_decodeMutex is locked.

[Peter Kasting, 2016/03/23 02:42:58]

Nit: Unclear what this means: can be called while, or should only be called
while?

[scroggo_chromium, 2016/03/24 13:59:45]

Should. Done.

+    bool decode(SegmentReader*, bool allDataReceived, size_t index, ImageDecoder**, SkBitmap*, ExternalMemoryAllocator*);
 
-    // ThreadSafeDataTransport is referenced by this class and m_encodedData.
-    // In case that ImageFrameGenerator get's deleted before m_encodedData,
-    // m_encodedData would hold the reference to it (and underlying data).
-    RefPtr<ThreadSafeDataTransport> m_data;
+    const SkISize m_fullSize;
 
-    bool m_isMultiFrame;
+    const bool m_isMultiFrame;
     bool m_decodeFailed;
     size_t m_frameCount;
     Vector<bool> m_hasAlpha;
     Vector<bool> m_frameComplete;
 
-    class ExternalMemoryAllocator;
-    OwnPtr<ExternalMemoryAllocator> m_externalAllocator;
-
     OwnPtr<ImageDecoderFactory> m_imageDecoderFactory;
 
     // Prevents multiple decode operations on the same data.
@@ -128,13 +118,6 @@ private:
 
     // Protect concurrent access to m_hasAlpha.
     Mutex m_alphaMutex;
-
-    // Our encoded image data returned in refEncodedData.
-    SkData* m_encodedData;
-
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<ExternalMemoryAllocator>;
-#endif
 };
 
 } // namespace blink