Bug 12401 – Avoid unnecessary allocations in CSS

• Component: CSS
• Status: RESOLVED FIXED

[Beth Dakin]

From <rdar://problem/4946877>

* SUMMARY
Patch attached which avoids several unnecessary allocations, cutting down on time in malloc and free.

1. css/MediaQueryEvaluator.cpp, css/MediaQueryEvaluator.h, css/cssstyleselector.cpp

Add a special method to the MediaQueryEvaluator class to avoid unnecessary turning a char * into a String object.  

2. loader/Cache.cpp

Don't turn a KURL's underlying String into another identical KURL.  Or, even better, you could change the prototype to createResource to just take a String& instead of a KURL& and pass the url.url() to that, which is what createResource really wants to be doing anyway (since it only ever uses the String), but is no less work.

[Beth Dakin]

Created attachment 12655 [details]
Nate's patch

Here is the patch attached to the radar bug.

[Darin Adler]

Comment on attachment 12655 [details]
Nate's patch

Looks good. r=me

[Maciej Stachowiak]

I don't think change #2 will actually save any allocations, since creating a KURL from the DeprecatedString inside another KURL won't actually call malloc. It will needlessly reparse it though, so still a good change. This needs a ChangeLog and should be run through regression tests.

[Darin Adler]

I ran the regression tests and wrote a change log.

Committed revision 19156.