[Webkit-unassigned] [Bug 74284] New: Bloom filter has unnecesary collisions

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=74284

           Summary: Bloom filter has unnecesary collisions
           Product: WebKit
           Version: 528+ (Nightly build)
          Platform: Unspecified
        OS/Version: Unspecified
            Status: UNCONFIRMED
          Severity: Minor
          Priority: P2
         Component: CSS
        AssignedTo: webkit-unassigned at lists.webkit.org
        ReportedBy: sandfeld at kde.org


The bloom filter used to optimize tag, id and class selectors on ancestor has a minor inefficiency in that the value those three different types all use the same hash value in the bloom-filter.

This means that if a site uses a class or id-selector on something that is also a common tag name, it bloom-filter will produce unnecessary false positives and forcing the styler into slow path.

My proposed solution is to add a salt to the hash so that the different selectors only collide by random chance, not because they use common words.

This is an minor optimization only, not a functionality bug.

-- 
Configure bugmail: https://bugs.webkit.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.