Bug 133043

Summary: AX: iOS: using AXAttributeCacheEnabler is too slow for every accessibilityElementAtIndex:
Product: WebKit Reporter: chris fleizach <cfleizach>
Component: AccessibilityAssignee: chris fleizach <cfleizach>
Status: RESOLVED FIXED    
Severity: Normal CC: aboxhall, apinheiro, commit-queue, dmazzoni, jcraig, jdiggs, mario, samuel_white, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
patch mario: review+

Description chris fleizach 2014-05-17 23:42:52 PDT 
On iOS, the attribute cache enabler is being used on every access to elementAtIndex. 
Sample shows that we're spending a lot of time creating and tearing down these objects. 

I think we need to provide the ability to enable and disable caching at a higher, more informed level, so that we can cut down on these costs.


<rdar://problem/16945180>
Comment 1 chris fleizach 2014-05-17 23:52:28 PDT 
Created attachment 231650 [details]
patch
Comment 2 Anders Carlsson 2014-05-18 07:23:23 PDT 
Comment on attachment 231650 [details]
patch

Who calls enableAttributeCaching and disableAttributeCaching, the OS?
Comment 3 chris fleizach 2014-05-18 07:48:10 PDT 
(In reply to comment #2)
> (From update of attachment 231650 [details])
> Who calls enableAttributeCaching and disableAttributeCaching, the OS?

The accessibility framework that is on the app side knows when a list of elements  is requested. That framework is able to start and stop the cache for us
Comment 4 Mario Sanchez Prada 2014-05-19 05:48:40 PDT 
Comment on attachment 231650 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=231650&action=review

> Source/WebCore/accessibility/ios/WebAccessibilityObjectWrapperIOS.mm:346
> +    m_object->axObjectCache()->startCachingComputedObjectAttributesUntilTreeMutates();

Perhaps you want to check whether axObjectCache() returns null here before using it?

> Source/WebCore/accessibility/ios/WebAccessibilityObjectWrapperIOS.mm:351
> +    m_object->axObjectCache()->stopCachingComputedObjectAttributes();

Same comment here
Comment 5 chris fleizach 2014-05-19 09:11:35 PDT 
(In reply to comment #4)
> (From update of attachment 231650 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=231650&action=review
> 
> > Source/WebCore/accessibility/ios/WebAccessibilityObjectWrapperIOS.mm:346
> > +    m_object->axObjectCache()->startCachingComputedObjectAttributesUntilTreeMutates();
> 
> Perhaps you want to check whether axObjectCache() returns null here before using it?
> 
> > Source/WebCore/accessibility/ios/WebAccessibilityObjectWrapperIOS.mm:351
> > +    m_object->axObjectCache()->stopCachingComputedObjectAttributes();
> 
> Same comment here

Done.

Thanks

http://trac.webkit.org/changeset/169047