Index: third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp |
diff --git a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp |
index 68e9334457a0978512762e0a267028649ede44d6..cbcad72ee0e124750f26edc9a90cd3c82d72748c 100644 |
--- a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp |
+++ b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp |
@@ -34,6 +34,7 @@ namespace blink { |
GIFImageDecoder::GIFImageDecoder(AlphaOption alphaOption, GammaAndColorProfileOption colorOptions, size_t maxDecodedBytes) |
: ImageDecoder(alphaOption, colorOptions, maxDecodedBytes) |
+ , m_purgeAggressively(false) |
, m_repetitionCount(cAnimationLoopOnce) |
{ |
} |
@@ -301,6 +302,38 @@ void GIFImageDecoder::decode(size_t index) |
if (failed()) |
return; |
+ if (!m_purgeAggressively) { |
+ // We don't want to cache so much that we cause a memory issue. |
+ // If we used a LRU cache we would fill it and then on next animation loop |
+ // we would need to decode all the frames again -- the LRU would give no |
+ // benefit and would consume more memory. |
+ // So instead, simply purge unused frames if caching all of the frames of |
+ // the image would use too much memory. |
scroggo_chromium
2016/06/27 19:04:32
Maybe specify what you mean by "too much memory"?
cblume
2016/06/27 23:11:17
Done.
|
+ // As we decode we will learn the total number of frames, and thus total |
+ // possible image memoroy used. |
scroggo_chromium
2016/06/27 19:04:32
memory*
cblume
2016/06/27 23:11:17
Done.
|
+ |
+ uint64_t frameArea = this->decodedSize().area(); |
scroggo_chromium
2016/06/27 19:04:32
nit: I don't think Blink uses this-> to call class
cblume
2016/06/27 23:11:17
Done.
|
+ // We are about to multiply by 4, which may require an extra bit of storage |
+ bool wouldOverflow = frameMemoryUsage > (1 << 62); |
scroggo_chromium
2016/06/27 19:04:32
It looks like "frameMemoryUsage" has not yet been
cblume
2016/06/27 23:11:17
Yeah, this was a mistake which I fixed in Patch Se
|
+ if (!wouldOverflow) { |
scroggo_chromium
2016/06/27 19:04:32
Just to make sure I understand - it looks like if
cblume
2016/06/27 23:11:17
Oh whoops.
Yeah, I definitely only wanted to allow
|
+ uint64_t frameMemoryUsage = frameArea * 4; // 4 bytes per pixel |
+ // We are about to multiply by a size_t, which does not have a fixed |
+ // size. |
+ // To simplify things, let's make sure our per-frame memory usage and |
+ // index can be stored in 32 bits and store the multiplicand in a 64-bit |
+ // number. |
+ wouldOverflow = frameMemoryUsage > (1 << 31); |
+ wouldOverflow |= index > (1 << 31); |
scroggo_chromium
2016/06/27 19:04:32
Why not combine these into one statement?
wou
cblume
2016/06/27 23:11:17
I like combining.
I think I prefer keeping the var
|
+ if (!wouldOverflow) { |
+ uint64_t totalMemoryUsage = static_cast<uint32_t>(frameMemoryUsage) |
scroggo_chromium
2016/06/27 19:04:32
Why do you need to cast this?
cblume
2016/06/27 23:11:18
Well, we could actually do uint128_t = uint64_t *
|
+ * static_cast<uint32_t>(index); |
+ if (wouldOverflow || totalMemoryUsage < m_maxDecodedBytes) { |
scroggo_chromium
2016/06/27 19:04:32
wouldOverflow can never be true here, right?
Also
cblume
2016/06/27 23:11:17
Oops, I definitely meant > (which means this shoul
|
+ m_purgeAggressively = true; |
+ } |
+ } |
+ } |
+ } |
+ |
Vector<size_t> framesToDecode; |
size_t frameToDecode = index; |
do { |
@@ -314,6 +347,9 @@ void GIFImageDecoder::decode(size_t index) |
return; |
} |
+ if (m_purgeAggressively) |
+ this->clearCacheExceptFrame(*i); |
scroggo_chromium
2016/06/27 19:04:32
nit: I think "this->" is unnecessary here?
cblume
2016/06/27 23:11:18
Done.
|
+ |
// We need more data to continue decoding. |
if (m_frameBufferCache[*i].getStatus() != ImageFrame::FrameComplete) |
break; |