Eliminate copies of encoded image data

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

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "platform/graphics/DeferredImageDecoder.h"
+
+#include "platform/SharedBuffer.h"
+#include "platform/image-decoders/ImageDecoderTestHelpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "wtf/RefPtr.h"
+
+namespace blink {
+
+/**
+ *  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_TRUE(decoder.get());
+
+    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(DeferredImageDecoderTestWoPlatform, mixImagesGif)
+{
+    mixImages("/LayoutTests/fast/images/resources/animated.gif", 818u, 1u);
+}
+
+TEST(DeferredImageDecoderTestWoPlatform, mixImagesPng)
+{
+    mixImages("/LayoutTests/fast/images/resources/mu.png", 910u, 0u);
+}
+
+TEST(DeferredImageDecoderTestWoPlatform, mixImagesJpg)
+{
+    mixImages("/LayoutTests/fast/images/resources/2-dht.jpg", 177u, 0u);
+}
+
+TEST(DeferredImageDecoderTestWoPlatform, mixImagesWebp)
+{
+    mixImages("/LayoutTests/fast/images/resources/webp-animated.webp", 142u, 1u);
+}
+
+TEST(DeferredImageDecoderTestWoPlatform, mixImagesBmp)
+{
+    mixImages("/LayoutTests/fast/images/resources/lenna.bmp", 122u, 0u);
+}
+
+TEST(DeferredImageDecoderTestWoPlatform, mixImagesIco)
+{
+    mixImages("/LayoutTests/fast/images/resources/1bit.ico", 70u, 0u);
+}
+
+} // namespace blink