GIF decoding to Index8, unit tests and misusing unit test as benchmark

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

 /*
  * Copyright (C) 2012 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
@@ skipping 85 matching lines @@
     componentSizes[2].set(size.width(), size.height());
     return true;
 }
 
 ImageFrameGenerator::ImageFrameGenerator(const SkISize& fullSize, PassRefPtr<SharedBuffer> data, bool allDataReceived, bool isMultiFrame)
     : m_fullSize(fullSize)
     , m_isMultiFrame(isMultiFrame)
     , m_decodeFailedAndEmpty(false)
     , m_decodeCount(0)
     , m_frameCount(0)
+    , m_decoderCanDecodeToIndex8(false)
 {
     setData(data.get(), allDataReceived);
 }
 
 ImageFrameGenerator::~ImageFrameGenerator()
 {
     ImageDecodingStore::instance().removeCacheIndexedByGenerator(this);
 }
 
 void ImageFrameGenerator::setData(PassRefPtr<SharedBuffer> data, bool allDataReceived)
 {
     m_data.setData(data.get(), allDataReceived);
 }
 
 void ImageFrameGenerator::copyData(RefPtr<SharedBuffer>* data, bool* allDataReceived)
 {
     SharedBuffer* buffer = 0;
     m_data.data(&buffer, allDataReceived);
     if (buffer)
         *data = buffer->copy();
 }
 
-bool ImageFrameGenerator::decodeAndScale(const SkImageInfo& info, size_t index, void* pixels, size_t rowBytes)
+bool ImageFrameGenerator::decodeAndScale(const SkImageInfo& info, size_t index, void* pixels, size_t rowBytes, SkPMColor ctable[], int* ctableCount)
 {
     // This method is called to populate a discardable memory owned by Skia.
 
     // Prevents concurrent decode or scale operations on the same image data.
     MutexLocker lock(m_decodeMutex);
 
     // This implementation does not support scaling so check the requested size.
     SkISize scaledSize = SkISize::Make(info.width(), info.height());
     ASSERT(m_fullSize == scaledSize);
 
     if (m_decodeFailedAndEmpty)
         return false;
 
     TRACE_EVENT2("blink", "ImageFrameGenerator::decodeAndScale", "generator", this, "decodeCount", m_decodeCount);
 
     m_externalAllocator = adoptPtr(new ExternalMemoryAllocator(info, pixels, rowBytes));
 
-    SkBitmap bitmap = tryToResumeDecode(scaledSize, index);
+    SkBitmap bitmap = tryToResumeDecode(scaledSize, index, info.colorType());
     if (bitmap.isNull())
         return false;
 
     // Don't keep the allocator because it contains a pointer to memory
     // that we do not own.
     m_externalAllocator.clear();
 
     ASSERT(bitmap.width() == scaledSize.width());
     ASSERT(bitmap.height() == scaledSize.height());
 
+    // If decoder cannot produce requested color type, return false.
+    if (bitmap.colorType() != info.colorType())
+        return false;
+
     bool result = true;
     SkAutoLockPixels bitmapLock(bitmap);
     // Check to see if decoder has written directly to the memory provided
     // by Skia. If not make a copy.
     if (bitmap.getPixels() != pixels)
         result = bitmap.copyPixelsTo(pixels, rowBytes * info.height(), rowBytes);
+    if (bitmap.colorType() == kIndex_8_SkColorType && ctable && bitmap.getColorTable()) {
+        memcpy(ctable, bitmap.getColorTable()->readColors(), bitmap.getColorTable()->count() * sizeof(SkPMColor));
+    }
+    if (ctableCount) {
+        // Based on SkImageGenerator API spec, ctableCount needs to be set ot 0 for other types.
+        *ctableCount = (bitmap.colorType() == kIndex_8_SkColorType && bitmap.getColorTable())
+            ? bitmap.getColorTable()->count()
+            : 0;
+    }
     return result;
 }
 
 bool ImageFrameGenerator::decodeToYUV(SkISize componentSizes[3], void* planes[3], size_t rowBytes[3])
 {
     // This method is called to populate a discardable memory owned by Skia.
 
     // Prevents concurrent decode or scale operations on the same image data.
     MutexLocker lock(m_decodeMutex);
 
@@ skipping 25 matching lines @@
 
     bool sizeUpdated = updateYUVComponentSizes(decoder.get(), componentSizes, ImageDecoder::ActualSize);
     RELEASE_ASSERT(sizeUpdated);
 
     bool yuvDecoded = decoder->decodeToYUV();
     if (yuvDecoded)
         setHasAlpha(0, false); // YUV is always opaque
     return yuvDecoded;
 }
 
-SkBitmap ImageFrameGenerator::tryToResumeDecode(const SkISize& scaledSize, size_t index)
+SkBitmap ImageFrameGenerator::tryToResumeDecode(const SkISize& scaledSize, size_t index, SkColorType outputColor)
 {
     TRACE_EVENT1("blink", "ImageFrameGenerator::tryToResumeDecodeAndScale", "index", static_cast<int>(index));
 
     ImageDecoder* decoder = 0;
     const bool resumeDecoding = ImageDecodingStore::instance().lockDecoder(this, m_fullSize, &decoder);
     ASSERT(!resumeDecoding || decoder);
 
     SkBitmap fullSizeImage;
-    bool complete = decode(index, &decoder, &fullSizeImage);
+    bool complete = decode(index, &decoder, &fullSizeImage, outputColor);
 
     if (!decoder)
         return SkBitmap();
     if (index >= m_frameComplete.size())
         m_frameComplete.resize(index + 1);
     m_frameComplete[index] = complete;
 
     // If we are not resuming decoding that means the decoder is freshly
     // created and we have ownership. If we are resuming decoding then
     // the decoder is owned by ImageDecodingStore.
@@ skipping 45 matching lines @@
     MutexLocker lock(m_alphaMutex);
     if (index >= m_hasAlpha.size()) {
         const size_t oldSize = m_hasAlpha.size();
         m_hasAlpha.resize(index + 1);
         for (size_t i = oldSize; i < m_hasAlpha.size(); ++i)
             m_hasAlpha[i] = true;
     }
     m_hasAlpha[index] = hasAlpha;
 }
 
-bool ImageFrameGenerator::decode(size_t index, ImageDecoder** decoder, SkBitmap* bitmap)
+bool ImageFrameGenerator::decode(size_t index, ImageDecoder** decoder, SkBitmap* bitmap, SkColorType outputColor)
 {
     TRACE_EVENT2("blink", "ImageFrameGenerator::decode", "width", m_fullSize.width(), "height", m_fullSize.height());
 
     ASSERT(decoder);
     SharedBuffer* data = 0;
     bool allDataReceived = false;
     bool newDecoder = false;
     m_data.data(&data, &allDataReceived);
 
     // Try to create an ImageDecoder if we are not given one.
@@ skipping 10 matching lines @@
     }
 
     if (!m_isMultiFrame && newDecoder && allDataReceived) {
         // If we're using an external memory allocator that means we're decoding
         // directly into the output memory and we can save one memcpy.
         ASSERT(m_externalAllocator.get());
         (*decoder)->setMemoryAllocator(m_externalAllocator.get());
     }
     (*decoder)->setData(data, allDataReceived);
 
-    ImageFrame* frame = (*decoder)->frameBufferAtIndex(index);
+    ImageFrame* frame = (*decoder)->frameBufferAtIndex(index, static_cast<ImageFrame::ColorType>(outputColor));
     // For multi-frame image decoders, we need to know how many frames are
     // in that image in order to release the decoder when all frames are
     // decoded. frameCount() is reliable only if all data is received and set in
     // decoder, particularly with GIF.
     if (allDataReceived)
         m_frameCount = (*decoder)->frameCount();
 
     (*decoder)->setData(0, false); // Unref SharedBuffer from ImageDecoder.
     (*decoder)->clearCacheExceptFrame(index);
     (*decoder)->setMemoryAllocator(0);
@@ skipping 47 matching lines @@
         return false;
 
     // Setting a dummy ImagePlanes object signals to the decoder that we want to do YUV decoding.
     decoder->setData(data, allDataReceived);
     OwnPtr<ImagePlanes> dummyImagePlanes = adoptPtr(new ImagePlanes);
     decoder->setImagePlanes(dummyImagePlanes.release());
 
     return updateYUVComponentSizes(decoder.get(), componentSizes, ImageDecoder::SizeForMemoryAllocation);
 }
 
+bool ImageFrameGenerator::canDecodeTo(size_t index, SkColorType outputType)
+{
+    // Skip decoding to get this information but return default.
+    return (outputType == kIndex_8_SkColorType && m_decoderCanDecodeToIndex8) || outputType == kN32_SkColorType;
+}
+
+
 } // namespace blink