Reland again "Decode GIF image frames on demand".

Source/core/platform/image-decoders/ImageDecoderTest.cpp

Index: Source/core/platform/image-decoders/ImageDecoderTest.cpp
diff --git a/Source/core/platform/image-decoders/ImageDecoderTest.cpp b/Source/core/platform/image-decoders/ImageDecoderTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b8f23931c9792af419e967c4128782b4dae7ac33
--- /dev/null
+++ b/Source/core/platform/image-decoders/ImageDecoderTest.cpp
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2013 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY 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.
+ */
+
+#include "config.h"
+
+#include "core/platform/image-decoders/ImageDecoder.h"
+
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/Vector.h"
+#include <gtest/gtest.h>
+
+using namespace WebCore;
+
+class TestImageDecoder : public ImageDecoder {
+public:
+    TestImageDecoder()
+        : ImageDecoder(ImageSource::AlphaNotPremultiplied, ImageSource::GammaAndColorProfileApplied)
+    {
+    }
+
+    virtual String filenameExtension() const OVERRIDE { return ""; }
+    virtual ImageFrame* frameBufferAtIndex(size_t) OVERRIDE { return 0; }
+
+    Vector<ImageFrame, 1>& frameBufferCache()
+    {
+        return m_frameBufferCache;
+    }
+
+    void resetRequiredPreviousFrames()
+    {
+        for (size_t i = 0; i < m_frameBufferCache.size(); ++i)
+            m_frameBufferCache[i].setRequiredPreviousFrameIndex(findRequiredPreviousFrame(i));
+    }
+
+    void initFrames(size_t numFrames, unsigned width = 100, unsigned height = 100)
+    {
+        setSize(width, height);
+        m_frameBufferCache.resize(numFrames);
+        for (size_t i = 0; i < numFrames; ++i)
+            m_frameBufferCache[i].setOriginalFrameRect(IntRect(0, 0, width, height));
+    }
+};
+
+TEST(ImageDecoderTest, requiredPreviousFrameIndex)
+{
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(6);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+
+    decoderFrameBufferCache[1].setDisposalMethod(ImageFrame::DisposeKeep);
+    decoderFrameBufferCache[2].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoderFrameBufferCache[3].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoderFrameBufferCache[4].setDisposalMethod(ImageFrame::DisposeKeep);
+
+    decoder->resetRequiredPreviousFrames();
+
+    // The first frame doesn't require any previous frame.
+    EXPECT_EQ(notFound, decoderFrameBufferCache[0].requiredPreviousFrameIndex());
+    // The previous DisposeNotSpecified frame is required.
+    EXPECT_EQ(0u, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+    // DisposeKeep is treated as DisposeNotSpecified.
+    EXPECT_EQ(1u, decoderFrameBufferCache[2].requiredPreviousFrameIndex());
+    // Previous DisposeOverwritePrevious frames are skipped.
+    EXPECT_EQ(1u, decoderFrameBufferCache[3].requiredPreviousFrameIndex());
+    EXPECT_EQ(1u, decoderFrameBufferCache[4].requiredPreviousFrameIndex());
+    EXPECT_EQ(4u, decoderFrameBufferCache[5].requiredPreviousFrameIndex());
+}
+
+TEST(ImageDecoderTest, requiredPreviousFrameIndexDisposeOverwriteBgcolor)
+{
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(3);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+
+    // Fully covering DisposeOverwriteBgcolor previous frame resets the starting state.
+    decoderFrameBufferCache[1].setDisposalMethod(ImageFrame::DisposeOverwriteBgcolor);
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(notFound, decoderFrameBufferCache[2].requiredPreviousFrameIndex());
+
+    // Partially covering DisposeOverwriteBgcolor previous frame is required by this frame.
+    decoderFrameBufferCache[1].setOriginalFrameRect(IntRect(50, 50, 50, 50));
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(1u, decoderFrameBufferCache[2].requiredPreviousFrameIndex());
+}
+
+TEST(ImageDecoderTest, requiredPreviousFrameIndexForFrame1)
+{
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(2);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(0u, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+
+    // The first frame with DisposeOverwritePrevious or DisposeOverwriteBgcolor
+    // resets the starting state.
+    decoderFrameBufferCache[0].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(notFound, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+    decoderFrameBufferCache[0].setDisposalMethod(ImageFrame::DisposeOverwriteBgcolor);
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(notFound, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+
+    // ... even if it partially covers.
+    decoderFrameBufferCache[0].setOriginalFrameRect(IntRect(50, 50, 50, 50));
+
+    decoderFrameBufferCache[0].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(notFound, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+    decoderFrameBufferCache[0].setDisposalMethod(ImageFrame::DisposeOverwriteBgcolor);
+    decoder->resetRequiredPreviousFrames();
+    EXPECT_EQ(notFound, decoderFrameBufferCache[1].requiredPreviousFrameIndex());
+}
+
+TEST(ImageDecoderTest, clearCacheExceptFrameDoNothing)
+{
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->clearCacheExceptFrame(0);
+
+    // This should not crash.
+    decoder->initFrames(20);
+    decoder->clearCacheExceptFrame(notFound);
+}
+
+TEST(ImageDecoderTest, clearCacheExceptFrameAll)
+{
+    const size_t numFrames = 10;
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(numFrames);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+    for (size_t i = 0; i < numFrames; ++i)
+        decoderFrameBufferCache[i].setStatus(i % 2 ? ImageFrame::FramePartial : ImageFrame::FrameComplete);
+
+    decoder->clearCacheExceptFrame(notFound);
+
+    for (size_t i = 0; i < numFrames; ++i) {
+        SCOPED_TRACE(testing::Message() << i);
+        EXPECT_EQ(ImageFrame::FrameEmpty, decoderFrameBufferCache[i].status());
+    }
+}
+
+TEST(ImageDecoderTest, clearCacheExceptFramePreverveClearExceptFrame)
+{
+    const size_t numFrames = 10;
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(numFrames);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+    for (size_t i = 0; i < numFrames; ++i)
+        decoderFrameBufferCache[i].setStatus(ImageFrame::FrameComplete);
+
+    decoder->resetRequiredPreviousFrames();
+    decoder->clearCacheExceptFrame(5);
+    for (size_t i = 0; i < numFrames; ++i) {
+        SCOPED_TRACE(testing::Message() << i);
+        if (i == 5)
+            EXPECT_EQ(ImageFrame::FrameComplete, decoderFrameBufferCache[i].status());
+        else
+            EXPECT_EQ(ImageFrame::FrameEmpty, decoderFrameBufferCache[i].status());
+    }
+}
+
+TEST(ImageDecoderTest, clearCacheExceptFramePreverveRequiredFrame)
+{
+    const size_t numFrames = 10;
+    OwnPtr<TestImageDecoder> decoder(adoptPtr(new TestImageDecoder()));
+    decoder->initFrames(numFrames);
+    Vector<ImageFrame, 1>& decoderFrameBufferCache = decoder->frameBufferCache();
+    for (size_t i = 0; i < numFrames; ++i)
+        decoderFrameBufferCache[i].setStatus(ImageFrame::FrameComplete);
+
+    decoderFrameBufferCache[2].setStatus(ImageFrame::FrameComplete);
+    decoderFrameBufferCache[3].clearPixelData();
+    decoderFrameBufferCache[4].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoderFrameBufferCache[5].setDisposalMethod(ImageFrame::DisposeOverwritePrevious);
+    decoderFrameBufferCache[6].clearPixelData();
+    decoder->resetRequiredPreviousFrames();
+
+    // 6 which is empty requires 3 which is empty, and 3 requires 2 which is complete,
+    // so 2 will be required by the next request of 6 and needs to be preserved.
+    decoder->clearCacheExceptFrame(6);
+    for (size_t i = 0; i < numFrames; ++i) {
+        SCOPED_TRACE(testing::Message() << i);
+        if (i == 2)
+            EXPECT_EQ(ImageFrame::FrameComplete, decoderFrameBufferCache[i].status());
+        else
+            EXPECT_EQ(ImageFrame::FrameEmpty, decoderFrameBufferCache[i].status());
+    }
+}