Move gif image decoder to SkCodec

third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, 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
@@ skipping 10 matching lines @@
  * 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 GIFImageDecoder_h
 #define GIFImageDecoder_h
 
 #include <memory>
 #include "platform/image-decoders/ImageDecoder.h"
+#include "platform/image-decoders/SegmentStream.h"
 #include "platform/wtf/Noncopyable.h"
-
-class GIFImageReader;
-
-typedef Vector<unsigned char> GIFRow;
+#include "third_party/skia/include/codec/SkCodec.h"
+#include "wtf/RefPtr.h"
 
 namespace blink {
 
 // This class decodes the GIF image format.
 class PLATFORM_EXPORT GIFImageDecoder final : public ImageDecoder {
   WTF_MAKE_NONCOPYABLE(GIFImageDecoder);
 
  public:
   GIFImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes);
   ~GIFImageDecoder() override;
 
-  enum GIFParseQuery { kGIFSizeQuery, kGIFFrameCountQuery };
-
   // ImageDecoder:
   String FilenameExtension() const override { return "gif"; }
   void OnSetData(SegmentReader* data) override;
   int RepetitionCount() const override;
   bool FrameIsCompleteAtIndex(size_t) const override;
   float FrameDurationAtIndex(size_t) const override;
-  // CAUTION: setFailed() deletes |m_reader|.  Be careful to avoid
-  // accessing deleted memory, especially when calling this from inside
-  // GIFImageReader!
-  bool SetFailed() override;

[scroggo_chromium, 2017/04/17 20:04:56]

Shouldn't we delete codec_ on failure?

[cblume, 2017/04/20 03:42:27]

Done.

-
-  // Callbacks from the GIF reader.
-  bool HaveDecodedRow(size_t frame_index,
-                      GIFRow::const_iterator row_begin,
-                      size_t width,
-                      size_t row_number,
-                      unsigned repeat_count,
-                      bool write_transparent_pixels);
-  bool FrameComplete(size_t frame_index);
-
-  // For testing.
-  bool ParseCompleted() const;
 
  private:
   // ImageDecoder:
-  void ClearFrameBuffer(size_t frame_index) override;
-  virtual void DecodeSize() { Parse(kGIFSizeQuery); }
+  void DecodeSize() override {}
   size_t DecodeFrameCount() override;
-  void InitializeNewFrame(size_t) override;
-  void Decode(size_t) override;
-
-  // Parses as much as is needed to answer the query, ignoring bitmap
-  // data. If parsing fails, sets the "decode failure" flag.
-  void Parse(GIFParseQuery);
-
-  // Reset the alpha tracker for this frame. Before calling this method, the
-  // caller must verify that the frame exists.
-  void OnInitFrameBuffer(size_t) override;
-
+  void InitializeNewFrame(size_t index) override;
+  void Decode(size_t index) override;
+  bool FrameStatusSufficientForSuccessors(size_t index) {
+    DCHECK(index < frame_buffer_cache_.size());
+    return frame_buffer_cache_[index].GetStatus() == ImageFrame::kFrameComplete;
+  }
   // When the disposal method of the frame is DisposeOverWritePrevious, the
   // next frame will use the previous frame's buffer as its starting state, so
   // we can't take over the data in that case. Before calling this method, the
   // caller must verify that the frame exists.
   bool CanReusePreviousFrameBuffer(size_t) const override;
 
-  bool current_buffer_saw_alpha_;
-  mutable int repetition_count_;
-  std::unique_ptr<GIFImageReader> reader_;
+  std::unique_ptr<SkCodec> codec_;
+  // segment_stream_ is a raw pointer because it passes ownership to
+  // codec_ when codec_ is created. However, we still need the
+  // pointer so we can append more data as it arrives.
+  SegmentStream* segment_stream_;
+  std::vector<SkCodec::FrameInfo> frame_infos_;
 };
 
 }  // namespace blink
 
 #endif