High CPU and increased memory usage fix for high-res (GIF, WEBP...) animations.

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

 /*
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple 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 39 matching lines @@
     RefPtr<BitmapImage> result = adoptRef(new BitmapImage(bitmap));
     result->m_frames[0].m_orientation = orientation;
     if (orientation.usesWidthAsHeight())
         result->m_sizeRespectingOrientation = result->m_size.transposedSize();
     return result.release();
 }
 
 BitmapImage::BitmapImage(ImageObserver* observer)
     : Image(observer)
     , m_currentFrame(0)
+    , m_cachedFrameIndex(0)
     , m_repetitionCount(cAnimationNone)
     , m_repetitionCountStatus(Unknown)
     , m_repetitionsComplete(0)
     , m_desiredFrameStartTime(0)
     , m_frameCount(0)
     , m_animationPolicy(ImageAnimationPolicyAllowed)
     , m_animationFinished(false)
     , m_allDataReceived(false)
     , m_haveSize(false)
     , m_sizeAvailable(false)
     , m_haveFrameCount(false)
 {
 }
 
 BitmapImage::BitmapImage(const SkBitmap& bitmap, ImageObserver* observer)
     : Image(observer)
     , m_size(bitmap.width(), bitmap.height())
     , m_currentFrame(0)
+    , m_cachedFrame(adoptRef(SkImage::NewFromBitmap(bitmap)))
+    , m_cachedFrameIndex(0)
     , m_repetitionCount(cAnimationNone)
     , m_repetitionCountStatus(Unknown)
     , m_repetitionsComplete(0)
     , m_frameCount(1)
     , m_animationPolicy(ImageAnimationPolicyAllowed)
     , m_animationFinished(true)
     , m_allDataReceived(true)
     , m_haveSize(true)
     , m_sizeAvailable(true)
     , m_haveFrameCount(true)
 {
     // Since we don't have a decoder, we can't figure out the image orientation.
     // Set m_sizeRespectingOrientation to be the same as m_size so it's not 0x0.
     m_sizeRespectingOrientation = m_size;
 
     m_frames.grow(1);
     m_frames[0].m_hasAlpha = !bitmap.isOpaque();
-    m_frames[0].m_frame = adoptRef(SkImage::NewFromBitmap(bitmap));
     m_frames[0].m_haveMetadata = true;
 }
 
 BitmapImage::~BitmapImage()
 {
     stopAnimation();
 }
 
 bool BitmapImage::currentFrameHasSingleSecurityOrigin() const
 {
     return true;
 }
 
-void BitmapImage::destroyDecodedData(bool destroyAll)
+void BitmapImage::destroyDecodedData()
 {
-    for (size_t i = 0; i < m_frames.size(); ++i) {
-        // The underlying frame isn't actually changing (we're just trying to
-        // save the memory for the framebuffer data), so we don't need to clear
-        // the metadata.
-        m_frames[i].clear(false);
-    }
-
-    m_source.clearCacheExceptFrame(destroyAll ? kNotFound : m_currentFrame);
+    m_cachedFrame.clear();
+    for (size_t i = 0; i < m_frames.size(); ++i)
+        m_frames[i].clear(true);
+    m_source.clearCacheExceptFrame(kNotFound);
     notifyMemoryChanged();
 }
 
-void BitmapImage::destroyDecodedDataIfNecessary()
-{
-    // Animated images >5MB are considered large enough that we'll only hang on
-    // to one frame at a time.
-    static const size_t cLargeAnimationCutoff = 5242880;
-    size_t allFrameBytes = 0;
-    for (size_t i = 0; i < m_frames.size(); ++i)
-        allFrameBytes += m_frames[i].m_frameBytes;
-
-    if (allFrameBytes > cLargeAnimationCutoff) {
-        destroyDecodedData(false);
-    }
-}
-
 void BitmapImage::notifyMemoryChanged()
 {
     if (getImageObserver())
         getImageObserver()->decodedSizeChangedTo(this, totalFrameBytes());
 }
 
 size_t BitmapImage::totalFrameBytes()
 {
     const size_t numFrames = frameCount();
     size_t totalBytes = 0;
     for (size_t i = 0; i < numFrames; ++i)
         totalBytes += m_source.frameBytesAtIndex(i);
     return totalBytes;
 }
 
-void BitmapImage::cacheFrame(size_t index)
+PassRefPtr<SkImage> BitmapImage::decodeAndCacheFrame(size_t index)
 {
     size_t numFrames = frameCount();
     if (m_frames.size() < numFrames)
         m_frames.grow(numFrames);
 
     // We are caching frame snapshots.  This is OK even for partially decoded frames,
     // as they are cleared by dataChanged() when new data arrives.
-    m_frames[index].m_frame = m_source.createFrameAtIndex(index);
+    RefPtr<SkImage> image = m_source.createFrameAtIndex(index);
+    m_cachedFrame = image;
+    m_cachedFrameIndex = index;
 
     m_frames[index].m_orientation = m_source.orientationAtIndex(index);
     m_frames[index].m_haveMetadata = true;
     m_frames[index].m_isComplete = m_source.frameIsCompleteAtIndex(index);
     if (repetitionCount(false) != cAnimationNone)
         m_frames[index].m_duration = m_source.frameDurationAtIndex(index);
     m_frames[index].m_hasAlpha = m_source.frameHasAlphaAtIndex(index);
     m_frames[index].m_frameBytes = m_source.frameBytesAtIndex(index);
 
     notifyMemoryChanged();
+    return image.release();
 }
 
 void BitmapImage::updateSize() const
 {
     if (!m_sizeAvailable || m_haveSize)
         return;
 
     m_size = m_source.size();
     m_sizeRespectingOrientation = m_source.size(RespectImageOrientation);
     m_haveSize = true;
@@ skipping 34 matching lines @@
     // and the frames aren't even guaranteed to appear in the file in the same
     // order as in the directory, so an arbitrary number of the frames might be
     // incomplete (if we ask for frames for which we've not yet reached the
     // start of the frame data), and any or none of them might be the particular
     // frame affected by appending new data here. Thus we have to clear all the
     // incomplete frames to be safe.
     for (size_t i = 0; i < m_frames.size(); ++i) {
         // NOTE: Don't call frameIsCompleteAtIndex() here, that will try to
         // decode any uncached (i.e. never-decoded or
         // cleared-on-a-previous-pass) frames!
-        if (m_frames[i].m_haveMetadata && !m_frames[i].m_isComplete)
+        if (m_frames[i].m_haveMetadata && !m_frames[i].m_isComplete) {
             m_frames[i].clear(true);
+            if (i == m_cachedFrameIndex)
+                m_cachedFrame.clear();
+        }
     }
 
     // Feed all the data we've seen so far to the image decoder.
     m_allDataReceived = allDataReceived;
     ASSERT(data());
     m_source.setData(*data(), allDataReceived);
 
     m_haveFrameCount = false;
     return isSizeAvailable();
 }
@@ skipping 40 matching lines @@
         if (orientation.usesWidthAsHeight()) {
             // The destination rect will have it's width and height already reversed for the orientation of
             // the image, as it was needed for page layout, so we need to reverse it back here.
             adjustedDstRect = FloatRect(adjustedDstRect.x(), adjustedDstRect.y(), adjustedDstRect.height(), adjustedDstRect.width());
         }
     }
 
     canvas->drawImageRect(image.get(), adjustedSrcRect, adjustedDstRect, &paint,
         WebCoreClampingModeToSkiaRectConstraint(clampMode));
 
-    if (currentFrameIsLazyDecoded())
+    if (image->isLazyGenerated())
         PlatformInstrumentation::didDrawLazyPixelRef(image->uniqueID());
 
     if (ImageObserver* observer = getImageObserver())
         observer->didDraw(this);
 
     startAnimation();
 }
 
 size_t BitmapImage::frameCount()
 {
@@ skipping 21 matching lines @@
 
     if (m_sizeAvailable && hasVisibleImageSize(size())) {
         BitmapImageMetrics::countDecodedImageType(m_source.filenameExtension());
         if (m_source.filenameExtension() == "jpg")
             BitmapImageMetrics::countImageOrientation(m_source.orientationAtIndex(0).orientation());
     }
 
     return m_sizeAvailable;
 }
 
-bool BitmapImage::ensureFrameIsCached(size_t index)
-{
-    if (index >= frameCount())
-        return false;
-
-    if (index >= m_frames.size() || !m_frames[index].m_frame)
-        cacheFrame(index);
-
-    return true;
-}
-
 PassRefPtr<SkImage> BitmapImage::frameAtIndex(size_t index)
 {
-    if (!ensureFrameIsCached(index))
+    if (index >= frameCount())
         return nullptr;
 
-    return m_frames[index].m_frame;
+    if (index == m_cachedFrameIndex && m_cachedFrame)
+        return m_cachedFrame;
+
+    return decodeAndCacheFrame(index);
 }
 
 bool BitmapImage::frameIsCompleteAtIndex(size_t index)
 {
     if (index < m_frames.size() && m_frames[index].m_haveMetadata && m_frames[index].m_isComplete)
         return true;
 
     return m_source.frameIsCompleteAtIndex(index);
 }
 
@@ skipping 195 matching lines @@
     m_frameTimer.clear();
 }
 
 void BitmapImage::resetAnimation()
 {
     stopAnimation();
     m_currentFrame = 0;
     m_repetitionsComplete = 0;
     m_desiredFrameStartTime = 0;
     m_animationFinished = false;
-
-    // For extremely large animations, when the animation is reset, we just throw everything away.
-    destroyDecodedDataIfNecessary();
+    m_cachedFrame.clear();
 }
 
 bool BitmapImage::maybeAnimated()
 {
     if (m_animationFinished)
         return false;
     if (frameCount() > 1)
         return true;
 
     return m_source.repetitionCount() != cAnimationNone;
@@ skipping 37 matching lines @@
         // because it is 0 (see comments on its declaration in ImageAnimation.h).
         if ((repetitionCount(true) != cAnimationLoopInfinite && m_repetitionsComplete > m_repetitionCount)
             || (m_animationPolicy == ImageAnimationPolicyAnimateOnce && m_repetitionsComplete > 0)) {
             m_animationFinished = true;
             m_desiredFrameStartTime = 0;
             --m_currentFrame;
             advancedAnimation = false;
         } else
             m_currentFrame = 0;
     }
-    destroyDecodedDataIfNecessary();
 
     // We need to draw this frame if we advanced to it while not skipping, or if
     // while trying to skip frames we hit the last frame and thus had to stop.
     if (skippingFrames != advancedAnimation)
         getImageObserver()->animationAdvanced(this);
+
     return advancedAnimation;
 }
 
 } // namespace blink