Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: e25d72b12cd9aea37de3dd55b87620b9c33ed13c
https://github.com/WebKit/WebKit/commit/e25d72b12cd9aea37de3dd55b87620b9c33ed13c
Author: Nathan Solomon <[email protected]>
Date: 2026-02-16 (Mon, 16 Feb 2026)
Changed paths:
M Source/WebCore/dom/Document.cpp
M Source/WebCore/dom/DocumentSharedObjectPool.cpp
M Source/WebCore/dom/DocumentSharedObjectPool.h
Log Message:
-----------
Reserve capacity for DocumentSharedObjectPool to improve perf of
parserSetAttributes
https://bugs.webkit.org/show_bug.cgi?id=306548
rdar://169193738
Reviewed by Ryosuke Niwa.
We spend ~12% of time in
WebCore::DocumentSharedObjectPool::cachedShareableElementDataWithAttributes
during parserSetAttributes which adds attributes to a HashSet<Ref,
ShareableElementDataHash>.
After a closer look at the disassembly of
cachedShareableElementDataWithAttributes(), we spend ~38%
of the time of this function doing quadratic probing.
Track peak element count (rounded up to nearest power of 2) per
RegistrableDomain.
On subsequent visits to the same domain, reserve the set's capacity upfront with
its previously known peak count.
After reserving initial capacity, profiling shows that
DocumentSharedObjectPool::cachedShareableElementDataWithAttributes now shows
fewer quadratic probing operations.
This also reduces hash set resize events that were occurring.
This shows a small perf improvement.
* Source/WebCore/dom/Document.cpp:
(WebCore::Document::setParsing):
* Source/WebCore/dom/DocumentSharedObjectPool.cpp:
(WebCore::peakSizeInPast):
(WebCore::DocumentSharedObjectPool::DocumentSharedObjectPool):
(WebCore::DocumentSharedObjectPool::~DocumentSharedObjectPool):
* Source/WebCore/dom/DocumentSharedObjectPool.h:
Canonical link: https://commits.webkit.org/307651@main
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