Eliminate copies of encoded image data

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef DecodingImageGenerator_h
 #define DecodingImageGenerator_h
 
 #include "platform/PlatformExport.h"
+#include "platform/image-decoders/SegmentReader.h"
 #include "third_party/skia/include/core/SkImageGenerator.h"
 #include "third_party/skia/include/core/SkImageInfo.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
+#include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 
 class SkData;
 
 namespace blink {
 
 class ImageFrameGenerator;
 
 // Implements SkImageGenerator, used by SkPixelRef to populate a discardable memory
 // with a decoded image frame. ImageFrameGenerator does the actual decoding.
 //
 class PLATFORM_EXPORT DecodingImageGenerator final : public SkImageGenerator {
     USING_FAST_MALLOC(DecodingImageGenerator);
     WTF_MAKE_NONCOPYABLE(DecodingImageGenerator);
 public:
     static SkImageGenerator* create(SkData*);
 
-    DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, size_t index);
+    DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, PassRefPtr<SegmentReader>, bool allDataReceived, size_t index);
     ~DecodingImageGenerator() override;
 
     void setCanYUVDecode(bool yes) { m_canYUVDecode = yes; }
 
 protected:
     SkData* onRefEncodedData() override;
 
     bool onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, SkPMColor table[], int* tableCount) override;
 
     bool onQueryYUV8(SkYUVSizeInfo*, SkYUVColorSpace*) const override;
 
     bool onGetYUV8Planes(const SkYUVSizeInfo&, void* planes[3]) override;
 
 private:
     RefPtr<ImageFrameGenerator> m_frameGenerator;
-    size_t m_frameIndex;
+    const RefPtr<SegmentReader> m_data; // Data source.
+    const bool m_allDataReceived;
+    const size_t m_frameIndex;
     bool m_canYUVDecode;
 };
 
 } // namespace blink
 
 #endif // DecodingImageGenerator_h_