Bug 179950 – RenderBlockFlow::layoutRunsAndFloatsInRange is O(n^2) for runs of inlines without any text

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Antti Koivisto]

It calls createBidiRunsForLine for each line. createBidiRunsForLine traverses past the end of the line until it finds the end of the current bidi run. If there is no text in the flow, it never finds anything and traverses the entire flow. This is O(n^2) for the number of renderers in the flow.

[Antti Koivisto]

Created attachment 327456 [details]
patch

[Simon Fraser (smfr)]

Comment on attachment 327456 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=327456&action=review

> Source/WebCore/platform/text/BidiResolver.h:248
> +    bool needsContinuePastEnd() { return static_cast<DerivedClass&>(*this).needsContinuePastEndInternal(); }

make the function const.

> Source/WebCore/platform/text/BidiResolver.h:281
> +    bool needsContinuePastEndInternal() { return true; }

const

> Source/WebCore/platform/text/BidiResolver.h:297
> +    bool needsContinuePastEndInternal();

const

> Source/WebCore/rendering/InlineIterator.h:590
> +inline bool InlineBidiResolver::needsContinuePastEndInternal()

const

[Antti Koivisto]

Created attachment 327466 [details]
patch

[WebKit Commit Bot]

Comment on attachment 327466 [details]
patch

Clearing flags on attachment: 327466

Committed r225110: <https://trac.webkit.org/changeset/225110>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/35674834>