Changeset 160260 in webkit

Timestamp:

Dec 6, 2013 4:45:11 PM (10 years ago)

Author:

timothy_horton@apple.com

Message:

[mac] Keep around more decoded image data, since it's purgeable
​https://bugs.webkit.org/show_bug.cgi?id=125273
<rdar://problem/13205438>

Reviewed by Simon Fraser.

No new tests, just an optimization.

Instead of throwing away decoded image data eagerly, allow the operating
system to manage the memory via the standard purgeability mechanism,
where it can.

This improves the performance on some pathological cases (extremely large
animated GIFs) by up to 8x.

• loader/cache/MemoryCache.cpp:

(WebCore::MemoryCache::pruneLiveResourcesToSize):
Don't prune live resources' decoded data if it is purgeable.

• platform/graphics/BitmapImage.cpp:

(WebCore::BitmapImage::destroyDecodedDataIfNecessary):
Don't eagerly throw away decoded image data if it's purgeable.

• loader/cache/CachedImage.h:
• loader/cache/CachedResource.h:

(WebCore::CachedResource::decodedDataIsPurgeable):

• platform/graphics/BitmapImage.h:
• platform/graphics/Image.h:

(WebCore::Image::decodedDataIsPurgeable):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• loader/cache/CachedImage.h (modified) (1 diff)
• loader/cache/CachedResource.h (modified) (1 diff)
• loader/cache/MemoryCache.cpp (modified) (1 diff)
• platform/graphics/BitmapImage.cpp (modified) (1 diff)
• platform/graphics/BitmapImage.h (modified) (1 diff)
• platform/graphics/Image.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-12-06  Tim Horton  <timothy_horton@apple.com>
+
+        [mac] Keep around more decoded image data, since it's purgeable
+        https://bugs.webkit.org/show_bug.cgi?id=125273
+        <rdar://problem/13205438>
+
+        Reviewed by Simon Fraser.
+
+        No new tests, just an optimization.
+
+        Instead of throwing away decoded image data eagerly, allow the operating
+        system to manage the memory via the standard purgeability mechanism,
+        where it can.
+
+        This improves the performance on some pathological cases (extremely large
+        animated GIFs) by up to 8x.
+
+        * loader/cache/MemoryCache.cpp:
+        (WebCore::MemoryCache::pruneLiveResourcesToSize):
+        Don't prune live resources' decoded data if it is purgeable.
+
+        * platform/graphics/BitmapImage.cpp:
+        (WebCore::BitmapImage::destroyDecodedDataIfNecessary):
+        Don't eagerly throw away decoded image data if it's purgeable.
+
+        * loader/cache/CachedImage.h:
+        * loader/cache/CachedResource.h:
+        (WebCore::CachedResource::decodedDataIsPurgeable):
+        * platform/graphics/BitmapImage.h:
+        * platform/graphics/Image.h:
+        (WebCore::Image::decodedDataIsPurgeable):
+
 2013-12-06  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/loader/cache/CachedImage.h

@@ -120 +120 @@
     virtual bool stillNeedsLoad() const OVERRIDE { return !errorOccurred() && status() == Unknown && !isLoading(); }
 
+    virtual bool decodedDataIsPurgeable() const OVERRIDE { return m_image && m_image->decodedDataIsPurgeable(); }
+
     // ImageObserver
     virtual void decodedSizeChanged(const Image*, int delta) OVERRIDE;

trunk/Source/WebCore/loader/cache/CachedResource.h

@@ -150 +150 @@
     unsigned decodedSize() const { return m_decodedSize; }
     unsigned overheadSize() const;
+
+    virtual bool decodedDataIsPurgeable() const { return false; }
     
     bool isLoaded() const { return !m_loading; } // FIXME. Method name is inaccurate. Loading might not have started yet.

trunk/Source/WebCore/loader/cache/MemoryCache.cpp

@@ -267 +267 @@
                 return;
 
+            if (current->decodedDataIsPurgeable())
+                continue;
+
             // Destroy our decoded data. This will remove us from 
             // m_liveDecodedResources, and possibly move us to a different LRU 

trunk/Source/WebCore/platform/graphics/BitmapImage.cpp

@@ -103 +103 @@
     static const unsigned cLargeAnimationCutoff = 5242880;
 
+    // If decoded data is purgeable, the operating system will
+    // take care of throwing it away when the system is under pressure.
+    if (decodedDataIsPurgeable())
+        return;
+
     // If we have decoded frames but there is no encoded data, we shouldn't destroy
     // the decoded image since we won't be able to reconstruct it later.

trunk/Source/WebCore/platform/graphics/BitmapImage.h

@@ -261 +261 @@
 
 private:
+    virtual bool decodedDataIsPurgeable() const OVERRIDE
+    {
+#if PLATFORM(MAC) && !PLATFORM(IOS) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1090
+    return true;
+#else
+    return false;
+#endif
+    }
+
     ImageSource m_source;
     mutable IntSize m_size; // The size to use for the overall image (will just be the size of the first image).

trunk/Source/WebCore/platform/graphics/Image.h

@@ -125 +125 @@
 
     virtual void destroyDecodedData(bool destroyAll = true) = 0;
+    virtual bool decodedDataIsPurgeable() const { return false; }
 
     SharedBuffer* data() { return m_encodedImageData.get(); }