[WIP] Move ImageDecoders to SkCodec

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp

Index: third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
index 0b76d3326f24edabb38900dfff72e8440d417c42..3ace861ae0532bf93449db3ea41afefe1c730211 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
@@ -23,88 +23,25 @@
 #include <memory>
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/BitmapImageMetrics.h"
-#include "platform/image-decoders/FastSharedBufferReader.h"
-#include "platform/image-decoders/bmp/BMPImageDecoder.h"
-#include "platform/image-decoders/gif/GIFImageDecoder.h"
-#include "platform/image-decoders/ico/ICOImageDecoder.h"
-#include "platform/image-decoders/jpeg/JPEGImageDecoder.h"
-#include "platform/image-decoders/png/PNGImageDecoder.h"
-#include "platform/image-decoders/webp/WEBPImageDecoder.h"
 #include "platform/instrumentation/PlatformInstrumentation.h"
 #include "platform/wtf/PtrUtil.h"
+#include "third_party/skia/include/core/SkImageInfo.h"
 
 namespace blink {
 
-inline bool MatchesJPEGSignature(const char* contents) {
-  return !memcmp(contents, "\xFF\xD8\xFF", 3);
-}
-
-inline bool MatchesPNGSignature(const char* contents) {
-  return !memcmp(contents, "\x89PNG\r\n\x1A\n", 8);
-}
-
-inline bool MatchesGIFSignature(const char* contents) {
-  return !memcmp(contents, "GIF87a", 6) || !memcmp(contents, "GIF89a", 6);
-}
-
-inline bool MatchesWebPSignature(const char* contents) {
-  return !memcmp(contents, "RIFF", 4) && !memcmp(contents + 8, "WEBPVP", 6);
-}
-
-inline bool MatchesICOSignature(const char* contents) {
-  return !memcmp(contents, "\x00\x00\x01\x00", 4);
-}
-
-inline bool MatchesCURSignature(const char* contents) {
-  return !memcmp(contents, "\x00\x00\x02\x00", 4);
-}
-
-inline bool MatchesBMPSignature(const char* contents) {
-  return !memcmp(contents, "BM", 2);
-}
-
-static constexpr size_t kLongestSignatureLength = sizeof("RIFF????WEBPVP") - 1;
-
 std::unique_ptr<ImageDecoder> ImageDecoder::Create(
     RefPtr<SegmentReader> data,
     bool data_complete,
     AlphaOption alpha_option,
     const ColorBehavior& color_behavior) {
-  // At least kLongestSignatureLength bytes are needed to sniff the signature.
-  if (data->size() < kLongestSignatureLength)
-    return nullptr;
-
   const size_t max_decoded_bytes =
       Platform::Current() ? Platform::Current()->MaxDecodedImageBytes()
                           : kNoDecodedImageByteLimit;
 
-  // Access the first kLongestSignatureLength chars to sniff the signature.
-  // (note: FastSharedBufferReader only makes a copy if the bytes are segmented)
-  char buffer[kLongestSignatureLength];
-  const FastSharedBufferReader fast_reader(data);
-  const char* contents =
-      fast_reader.GetConsecutiveData(0, kLongestSignatureLength, buffer);
-
   std::unique_ptr<ImageDecoder> decoder;
-  if (MatchesJPEGSignature(contents)) {
-    decoder.reset(
-        new JPEGImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  } else if (MatchesPNGSignature(contents)) {
-    decoder.reset(
-        new PNGImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  } else if (MatchesGIFSignature(contents)) {
-    decoder.reset(
-        new GIFImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  } else if (MatchesWebPSignature(contents)) {
-    decoder.reset(
-        new WEBPImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  } else if (MatchesICOSignature(contents) || MatchesCURSignature(contents)) {
-    decoder.reset(
-        new ICOImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  } else if (MatchesBMPSignature(contents)) {
-    decoder.reset(
-        new BMPImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
-  }
+
+  decoder.reset(
+      new ImageDecoder(alpha_option, color_behavior, max_decoded_bytes));
 
   if (decoder)
     decoder->SetData(std::move(data), data_complete);
@@ -112,13 +49,31 @@ std::unique_ptr<ImageDecoder> ImageDecoder::Create(
   return decoder;
 }
 
-bool ImageDecoder::HasSufficientDataToSniffImageType(const SharedBuffer& data) {
-  return data.size() >= kLongestSignatureLength;
+ImageDecoder::ImageDecoder(AlphaOption alpha_option,
+                           const ColorBehavior& color_behavior,
+                           size_t max_decoded_bytes)
+    : premultiply_alpha_(alpha_option == kAlphaPremultiplied),
+      color_behavior_(color_behavior),
+      max_decoded_bytes_(max_decoded_bytes),
+      purge_aggressively_(false),
+      codec_() {}
+void ImageDecoder::OnSetData(SegmentReader* data) {
+  if (data) {
+    if (!codec_) {
+      SkCodec* codec = SkCodec::NewFromData(data->GetAsSkData());
+      if (codec)
+        codec_.reset(codec);
+      else
+        return;
+    }
+    SkImageInfo image_info = codec_->getInfo();
+    SetSize(image_info.width(), image_info.height());
+  }
 }
 
 size_t ImageDecoder::FrameCount() {
   const size_t old_size = frame_buffer_cache_.size();
-  const size_t new_size = DecodeFrameCount();
+  const size_t new_size = codec_ ? codec_->getFrameCount() : 0;
   if (old_size != new_size) {
     frame_buffer_cache_.resize(new_size);
     for (size_t i = old_size; i < new_size; ++i) {
@@ -129,6 +84,70 @@ size_t ImageDecoder::FrameCount() {
   return new_size;
 }
 
+void ImageDecoder::Decode(size_t index) {
+  if (!codec_)
+    return;
+
+  DCHECK(!Failed());
+  DCHECK_LT(index, frame_buffer_cache_.size());
+
+  UpdateAggressivePurging(index);
+  SkImageInfo imageInfo = codec_->getInfo()
+                              .makeColorType(kN32_SkColorType)
+                              .makeColorSpace(ColorSpaceForSkImages());
+
+  SkCodec::Options options;
+  options.fFrameIndex = index;
+  options.fZeroInitialized = SkCodec::kYes_ZeroInitialized;
+
+  ImageFrame& frame = frame_buffer_cache_[index];
+  if (frame.GetStatus() == ImageFrame::kFrameEmpty) {
+    size_t required_previous_frame_index = frame.RequiredPreviousFrameIndex();
+    if (required_previous_frame_index == WTF::kNotFound) {
+      frame.AllocatePixelData(Size().Width(), Size().Height(),
+                              ColorSpaceForSkImages());
+    } else {
+      ImageFrame& required_previous_frame =
+          frame_buffer_cache_[required_previous_frame_index];
+
+      if (required_previous_frame.GetStatus() != ImageFrame::kFrameComplete)
+        Decode(required_previous_frame_index);
+
+      // We try to reuse |required_previous_frame| as starting state to avoid
+      // copying. If CanReusePreviousFrameBuffer returns false, we must copy
+      // the data since |required_previous_frame| is necessary to decode this
+      // or later frames. In that case copy the data instead.
+      if ((!CanReusePreviousFrameBuffer(index) ||
+           !frame.TakeBitmapDataIfWritable(&required_previous_frame)) &&
+          !frame.CopyBitmapData(required_previous_frame)) {
+        SetFailed();
+        return;
+      }
+      options.fHasPriorFrame = true;
+    }
+  }
+
+  SkCodec::Result result =
+      codec_->getPixels(imageInfo, frame.Bitmap().getPixels(),
+                        frame.Bitmap().rowBytes(), &options, nullptr, nullptr);
+  switch (result) {
+    case SkCodec::kSuccess:
+      frame.SetPixelsChanged(true);
+      frame.SetStatus(ImageFrame::kFrameComplete);
+      PostDecodeProcessing(index);
+      break;
+    default:
+      SetFailed();
+      return;
+  }
+}
+
+bool ImageDecoder::SetFailed() {
+  codec_ = nullptr;
+  failed_ = true;
+  return false;
+}
+
 ImageFrame* ImageDecoder::FrameBufferAtIndex(size_t index) {
   if (index >= FrameCount())
     return 0;
@@ -155,9 +174,22 @@ bool ImageDecoder::FrameHasAlphaAtIndex(size_t index) const {
 }
 
 bool ImageDecoder::FrameIsCompleteAtIndex(size_t index) const {
-  // Animated images override this method to return the status based on the data
-  // received for the queried frame.
-  return IsAllDataReceived();
+  if (!codec_)
+    return false;
+
+  if (codec_->getFrameCount() <= (int)index)
+    return false;
+
+  if (frame_buffer_cache_.IsEmpty())
+    return false;
+
+  return frame_buffer_cache_[0].GetStatus() == ImageFrame::kFrameComplete;
+}
+
+float ImageDecoder::FrameDurationAtIndex(size_t index) const {
+  if (index < frame_buffer_cache_.size())
+    return frame_buffer_cache_[index].Duration();
+  return 0;
 }
 
 bool ImageDecoder::FrameIsDecodedAtIndex(size_t index) const {
@@ -357,14 +389,61 @@ bool ImageDecoder::InitFrameBuffer(size_t frame_index) {
     }
   }
 
-  OnInitFrameBuffer(frame_index);
-
   // Update our status to be partially complete.
   buffer->SetStatus(ImageFrame::kFramePartial);
 
   return true;
 }
 
+int ImageDecoder::RepetitionCount() {
+  if (!codec_)
+    return kAnimationLoopOnce;
+
+  DCHECK(!Failed());
+
+  // packets sent back by the webserver) not always.
+  // SkCodec will parse forward in the file if the repetition count has not been
+  // seen yet.
+  int repetition_count = codec_->getRepetitionCount();
+  switch (repetition_count) {
+    case 0: {
+      size_t frame_count = codec_->getFrameCount();
+      if (IsAllDataReceived() && frame_count == 1)
+        return kAnimationNone;
+      return kAnimationLoopOnce;
+    }
+    case SkCodec::kRepetitionCountInfinite:
+      return kAnimationLoopInfinite;
+    default:
+      return repetition_count;
+  }
+}
+
+bool ImageDecoder::CanReusePreviousFrameBuffer(size_t index) const {
+  DCHECK(index < frame_buffer_cache_.size());
+
+  // If the current frame and the next frame depend on the same frame, we cannot
+  // reuse the old frame. We must preserve it for the next frame.
+  //
+  // However, if the current and next frame depend on different frames then we
+  // know the current frame is the last one to use the frame it depends on. That
+  // means the current frame can reuse the previous frame buffer.
+  //
+  // If we do not have information about the next frame yet, we cannot assume it
+  // is safe to reuse the previous frame buffer.
+
+  if (index + 1 >= frame_buffer_cache_.size())
+    return false;
+
+  const ImageFrame& frame = frame_buffer_cache_[index];
+  size_t required_frame_index = frame.RequiredPreviousFrameIndex();
+
+  const ImageFrame& next_frame = frame_buffer_cache_[index + 1];
+  size_t next_required_frame_index = next_frame.RequiredPreviousFrameIndex();
+
+  return required_frame_index != next_required_frame_index;
+}
+
 void ImageDecoder::UpdateAggressivePurging(size_t index) {
   if (purge_aggressively_)
     return;
@@ -455,6 +534,36 @@ size_t ImageDecoder::FindRequiredPreviousFrame(size_t frame_index,
   }
 }
 
+void ImageDecoder::InitializeNewFrame(size_t index) {
+  DCHECK(codec_);
+
+  ImageFrame& frame = frame_buffer_cache_[index];
+  // SkCodec does not inform us if only a portion of the image was updated
+  // in the current frame. Because of this, rather than correctly filling in
+  // the frame rect, we set the frame rect to be the image's full size.
+  IntSize fullImageSize = Size();
+  frame.SetOriginalFrameRect(IntRect(IntPoint(), fullImageSize));
+
+  SkCodec::FrameInfo frame_info;
+  memset(&frame_info, 0, sizeof(frame_info));
+  codec_->getFrameInfo(index, &frame_info);
+  frame.SetDuration(frame_info.fDuration);
+  frame.SetHasAlpha(!SkAlphaTypeIsOpaque(frame_info.fAlphaType));
+  size_t required_previous_frame_index = WTF::kNotFound;
+
+  if (frame_info.fRequiredFrame > 0) {
+    required_previous_frame_index =
+        static_cast<size_t>(frame_info.fRequiredFrame);
+  }
+
+  frame.SetRequiredPreviousFrameIndex(required_previous_frame_index);
+
+  // The disposal method is not required any more, but is left in place
+  // for the other image decoders that do not yet rely on SkCodec.
+  // For now, fill it with DisposeKeep.
+  frame.SetDisposalMethod(ImageFrame::kDisposeKeep);
+}
+
 ImagePlanes::ImagePlanes() {
   for (int i = 0; i < 3; ++i) {
     planes_[i] = 0;