Bug 83125 – Web Inspector: linearise aggregate's retaining size calculation

• Component: Web Inspector (Deprecated)
• Status: RESOLVED FIXED

[Ilya Tikhonovsky]

It gives us no performance gain but gives us the flexibility for future improvements.

[Ilya Tikhonovsky]

Created attachment 135529 [details]
Patch

[Ilya Tikhonovsky]

Created attachment 135579 [details]
Patch

[Yury Semikhatsky]

Comment on attachment 135579 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=135579&action=review

> Source/WebCore/ChangeLog:15
> [phone]  Ilya Tikhonovsky  <[e-mail]>

Remove duplicate entry.

> Source/WebCore/inspector/front-end/HeapSnapshot.js:1136
> +        for (var nodeIndex = this._rootNodeIndex; nodeIndex < onlyNodesLength; nodeIndex += nodeFieldsCount) {

We may want to extract this loop into its own method so that we can measure its performance without _calculateClassesRetainedSize. WDYT?

> Source/WebCore/inspector/front-end/HeapSnapshot.js:1138
> +            var selfSize = onlyNodes[nodeIndex + selfSizeOffset];

Given that in other places here we use "node" to get corresponding field value I'd rather use it here as well for consistency. Does it have any impact on the performance of this method?

> Source/WebCore/inspector/front-end/HeapSnapshot.js:1195
> +            var dominatedIndexFrom = firstDominatedNodeIndex[nodeIndex / nodeFieldCount];

var nodeOrdinal = nodeIndex / nodeFieldCount; ?

[Ilya Tikhonovsky]

Created attachment 135588 [details]
Patch

[Ilya Tikhonovsky]

(In reply to comment #3)
> (From update of attachment 135579 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=135579&action=review
> 
> > Source/WebCore/ChangeLog:15
> > [phone]  Ilya Tikhonovsky  <[e-mail] (:loislo) (c)>
> 
> Remove duplicate entry.

done.

> 
> > Source/WebCore/inspector/front-end/HeapSnapshot.js:1136
> > +        for (var nodeIndex = this._rootNodeIndex; nodeIndex < onlyNodesLength; nodeIndex += nodeFieldsCount) {
> 
> We may want to extract this loop into its own method so that we can measure its performance without _calculateClassesRetainedSize. WDYT?
> 
> > Source/WebCore/inspector/front-end/HeapSnapshot.js:1138
> > +            var selfSize = onlyNodes[nodeIndex + selfSizeOffset];
> 
> Given that in other places here we use "node" to get corresponding field value I'd rather use it here as well for consistency. Does it have any impact on the performance of this method?

v8 doesn't inline our getters. I'd like to inline classIndex too but it a separate patch. Also in general we have no control over filter function.

> 
> > Source/WebCore/inspector/front-end/HeapSnapshot.js:1195
> > +            var dominatedIndexFrom = firstDominatedNodeIndex[nodeIndex / nodeFieldCount];
> 
> var nodeOrdinal = nodeIndex / nodeFieldCount; ?

done

[Alexei Filippov]

lgtm

[Ilya Tikhonovsky]

Committed r113194: <http://trac.webkit.org/changeset/113194>