Bug 90276

Summary: Optimize Element::getAttributeNS() by replacing String with AtomicString
Product: WebKit Reporter: Kentaro Hara <haraken>
Component: DOMAssignee: Kentaro Hara <haraken>
Status: RESOLVED FIXED    
Severity: Normal CC: ap, cmarcelo, rniwa, webkit.review.bot
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 90246    
Attachments:
Description Flags
Performance test
none
Updated performance test
none
Patch none

Kentaro Hara
Reported 2012-06-29 05:37:11 PDT
In r121439, we changed the argument type of Element::getAttribute() from String to AtomicString for optimization. We can also change the argument type of Element::getAttributeNS() from String to AtomicString. Actually this change affects V8 performance only. [JSC without the patch] The binding code converts a given JavaScript string to a String -> the String is passed to getAttributeNS() -> the String is converted to an AtomicString when it is passed to QualifiedName() constructor. [JSC with the patch] The binding code converts a given JavaScript string to a String -> the String is converted to an AtomicString when it is passed to getAttributeNS() -> the AtomicString is passed to QualifiedName() constructor. [V8 without the patch] The binding code retrieves a cached external String for a given JavaScript string -> the String is passed to getAttributeNS() -> the String is converted to AtomicString when it is passed to QualifiedName() constructor. [V8 with the patch] The binding code retrieves a cached external AtomicString for a given JavaScript string -> the AtomicString is passed to getAttributeNS() -> the AtomicString is passed to QualifiedName() constructor. In this way, in JSC, the change affects where a String is converted to an AtomicString. On the other hand, in V8, (since the AtomicString is already cached,) we can skip the conversion step.
Attachments
Performance test (1.35 KB, text/html)
2012-06-29 05:38 PDT, Kentaro Hara 		no flags
Details
Updated performance test (1.36 KB, text/html)
2012-06-29 05:43 PDT, Kentaro Hara 		no flags
Details
Patch (4.11 KB, patch)
2012-06-29 05:44 PDT, Kentaro Hara 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Kentaro Hara
Comment 1 2012-06-29 05:38:20 PDT
Created attachment 150156 [details] Performance test
Kentaro Hara
Comment 2 2012-06-29 05:43:32 PDT
Created attachment 150158 [details] Updated performance test
Kentaro Hara
Comment 3 2012-06-29 05:44:36 PDT
Created attachment 150159 [details] Patch
Adam Barth
Comment 4 2012-07-27 01:05:18 PDT
Comment on attachment 150159 [details] Patch Based on further discussion in #webkit, my current understanding is that ap is ok with these patches. I'm going to r+ them, but please give ap a chance to respond before landing.
WebKit Review Bot
Comment 5 2012-07-27 18:21:31 PDT
Comment on attachment 150159 [details] Patch Clearing flags on attachment: 150159 Committed r123944: <http://trac.webkit.org/changeset/123944>
WebKit Review Bot
Comment 6 2012-07-27 18:21:35 PDT
All reviewed patches have been landed. Closing bug.
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