Bug 133043 – AX: iOS: using AXAttributeCacheEnabler is too slow for every accessibilityElementAtIndex:

• Status: RESOLVED
• Resolution: FIXED
• Component: Accessibility

[chris fleizach]

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>

[chris fleizach]

Created attachment 231650 [details]
patch

[Anders Carlsson]

Comment on attachment 231650 [details]
patch

Who calls enableAttributeCaching and disableAttributeCaching, the OS?

[chris fleizach]

(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

[Mario Sanchez Prada]

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

[chris fleizach]

(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