fix: cache isFireFox() result in CSSParser to avoid repeated UA scan - #1706
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498755303 wants to merge 2 commits into
Open
fix: cache isFireFox() result in CSSParser to avoid repeated UA scan#1706498755303 wants to merge 2 commits into
498755303 wants to merge 2 commits into
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release version 1.0.0-rc.32
recordResult() runs once per CSS fragment and called isFireFox() every time, so a single stylesheet triggers thousands of avoidable UA substring scans. Cache the result into this.isFF once at the start of exec(), reuse it in recordResult() and the return value, and reset it in reset().
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Background
recordResult()insrc/sandbox/scoped_css.tsruns once per CSS fragment andcalled
isFireFox()every time. Parsing a single stylesheet therefore triggersthousands of avoidable user-agent substring scans.
Change
isFF, cached once at the start ofexec().this.isFFinrecordResult()and theexec()return value.reset().UA detection now runs once per
exec()instead of once per fragment.