Bug 251700 - DisplayList::ItemBuffer wastes a lot of vector capacity
Summary: DisplayList::ItemBuffer wastes a lot of vector capacity
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: WebKit Local Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Simon Fraser (smfr)
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2023-02-03 10:29 PST by Simon Fraser (smfr)
Modified: 2023-02-04 17:07 PST (History)
6 users (show)

See Also:

Attachments
Patch (1.58 KB, patch)
2023-02-04 12:12 PST, Simon Fraser (smfr) 		no flags Details | Formatted Diff | Diff
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Description Simon Fraser (smfr) 2023-02-03 10:29:01 PST 
Using the patch in bug 186698, and testing on a wikipedia page, we see that DisplayList::ItemBuffer::ItemBuffer() wastes a lot of vector capacity:

Wasted capacity: 31632 bytes (used 0 of 31632 bytes, utilization: 0.00%) - 659 allocations
1   0x2fd3346e7 WTF::VectorBuffer<WebCore::DisplayList::ItemBufferHandle, 2ul, WTF::FastMalloc>::VectorBuffer()
2   0x2fd3313d1 WebCore::DisplayList::ItemBuffer::ItemBuffer()
3   0x2fd33119c WebCore::DisplayList::DisplayList::itemBuffer()
4   0x2fd3311fe WebCore::DisplayList::DisplayList::setItemBufferWritingClient(WebCore::DisplayList::ItemBufferWritingClient*)
5   0x2fd336a1b WebCore::DisplayList::InMemoryDisplayList::InMemoryDisplayList()
6   0x2fd30735a WebCore::FontCascade::displayListForTextRun(WebCore::GraphicsContext&, WebCore::TextRun const&, unsigned int, std::__1::optional<unsigned int>, WebCore::FontCascade::CustomFontNotReadyAction) const
7   0x2fcc5efd4 WebCore::GlyphDisplayListCache::get(void const*, WebCore::FontCascade const&, WebCore::GraphicsContext&, WebCore::TextRun const&)
8   0x2fcdf55a2 WebCore::TextBoxPainter<WebCore::InlineIterator::BoxModernPath>::paintForeground(WebCore::StyledMarkedText const&)
9   0x2fcdf3efe WebCore::TextBoxPainter<WebCore::InlineIterator::BoxModernPath>::paintForegroundAndDecorations()
10  0x2fcdf3656 WebCore::TextBoxPainter<WebCore::InlineIterator::BoxModernPath>::paint()
11  0x2fc7e0b49 WebCore::LayoutIntegration::InlineContentPainter::paintDisplayBox(WebCore::InlineDisplay::Box const&)
12  0x2fc7e0db5 WebCore::LayoutIntegration::InlineContentPainter::paint()
13  0x2fc7e54a8 WebCore::LayoutIntegration::LineLayout::paint(WebCore::PaintInfo&, WebCore::LayoutPoint const&, WebCore::RenderInline const*)
14  0x2fcc96d0e WebCore::RenderBlock::paintObject(WebCore::PaintInfo&, WebCore::LayoutPoint const&)
Comment 1 Radar WebKit Bug Importer 2023-02-03 10:29:26 PST 
<rdar://problem/105011333>
Comment 2 Simon Fraser (smfr) 2023-02-04 12:12:26 PST 
Created attachment 464837 [details]
Patch
Comment 3 EWS 2023-02-04 17:07:17 PST 
Committed 259861@main (b7a8c3d2ff89): <https://commits.webkit.org/259861@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 464837 [details].