Eliminate copies of encoded image data

third_party/WebKit/Source/platform/graphics/DeferredImageDecoderTest.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
@@ skipping 12 matching lines @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/graphics/DeferredImageDecoder.h"
 
 #include "platform/SharedBuffer.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "platform/graphics/ImageDecodingStore.h"
 #include "platform/graphics/ImageFrameGenerator.h"
 #include "platform/graphics/test/MockImageDecoder.h"
+#include "platform/testing/UnitTestHelpers.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebTaskRunner.h"
 #include "public/platform/WebThread.h"
 #include "public/platform/WebTraceLocation.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/core/SkPixmap.h"
@@ skipping 358 matching lines @@
     m_lazyDecoder->setData(*m_data, false);
     m_lazyDecoder->createFrameAtIndex(0);
     m_lazyDecoder->createFrameAtIndex(1);
     m_lazyDecoder->setData(*m_data, true);
     // Clears only the first frame (0 bytes). If DeferredImageDecoder doesn't
     // check with the actual decoder it reports 4 bytes instead.
     size_t frameBytesCleared = m_lazyDecoder->clearCacheExceptFrame(1);
     EXPECT_EQ(static_cast<size_t>(0), frameBytesCleared);
 }
 
+// FIXME (scroggo): combine this with ImageDecoderTestHelpers?

[Peter Kasting, 2016/04/12 22:56:25]

Nit: We prefer TODO to FIXME, I believe.

[scroggo_chromium, 2016/04/13 12:16:42]

Done.

+static PassRefPtr<SharedBuffer> readFile(const char* fileName)
+{
+    String filePath = testing::blinkRootDir();
+    filePath.append(fileName);
+    return testing::readFromFile(filePath);
+}
+
+/**
+ *  Used to test decoding SkImages out of order.
+ *  e.g.
+ *  SkImage* imageA = decoder.createFrameAtIndex(0);
+ *  // supply more (but not all) data to the decoder
+ *  SkImage* imageB = decoder.createFrameAtIndex(laterFrame);
+ *  imageB->preroll();
+ *  imageA->preroll();
+ *
+ *  This results in using the same ImageDecoder (in the ImageDecodingStore) to
+ *  decode less data the second time. This test ensures that it is safe to do
+ *  so.
+ *
+ *  @param fileName File to decode
+ *  @param bytesForFirstFrame Number of bytes needed to return an SkImage
+ *  @param laterFrame Frame to decode with almost complete data. Can be 0.
+ */
+static void mixImages(const char* fileName, size_t bytesForFirstFrame, size_t laterFrame)
+{
+    RefPtr<SharedBuffer> file = readFile(fileName);
+    ASSERT_NE(file, nullptr);
+
+    OwnPtr<DeferredImageDecoder> decoder = DeferredImageDecoder::create(*file.get(), ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileIgnored);
+    ASSERT_NE(decoder, nullptr);
+
+    RefPtr<SharedBuffer> partialFile = SharedBuffer::create(file->data(), bytesForFirstFrame);
+    decoder->setData(*partialFile.get(), false);
+    RefPtr<SkImage> partialImage = decoder->createFrameAtIndex(0);
+
+    RefPtr<SharedBuffer> almostCompleteFile = SharedBuffer::create(file->data(), file->size() - 1);
+    decoder->setData(*almostCompleteFile.get(), false);
+    RefPtr<SkImage> imageWithMoreData = decoder->createFrameAtIndex(laterFrame);
+
+    imageWithMoreData->preroll();
+    partialImage->preroll();
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesGif)
+{
+    mixImages("/LayoutTests/fast/images/resources/animated.gif", 818u, 1u);
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesPng)
+{
+    mixImages("/LayoutTests/fast/images/resources/mu.png", 910u, 0u);
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesJpg)
+{
+    mixImages("/LayoutTests/fast/images/resources/2-dht.jpg", 177u, 0u);
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesWebp)
+{
+    mixImages("/LayoutTests/fast/images/resources/webp-animated.webp", 142u, 1u);
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesBmp)
+{
+    mixImages("/LayoutTests/fast/images/resources/lenna.bmp", 122u, 0u);
+}
+
+TEST_F(DeferredImageDecoderTest, mixImagesIco)
+{
+    mixImages("/LayoutTests/fast/images/resources/1bit.ico", 70u, 0u);
+}
+
 } // namespace blink