1486623 - DOM tree memory reporting likely misses some nodes

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, enhancement)

Description

[Boris Zbarsky [:bzbarsky]]

There are two places we do memory reporting on DOM trees: nsDocument::DocAddSizeOfExcludingThis and xpc::OrphanReporter

The former uses AllChildrenIterator so it will miss nodes not in the flat tree, as well as ShadowRoots.

The latter does just a firstChild/nextSibling walk, so misses all the Shadow DOM stuff.

We should think about a way to make these walks actually hit all nodes.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Attachment: Skip less nodes when reporting memory, and report ShadowRoot's StyleSheets.

This moves all the node-specific reporting to nsIDocument.

OrphanReporter delegates all the reporting to that and then returns the sum of
all sizes, which is not ideal but was pre-existing.

Also, I moved the main mStyleSheets size reporting to DocumentOrShadowRoot for
it to be shared between document and ShadowRoot.

I'll add memory reporting for the computed stylesheet maps and such in the
ShadowRoot in a followup.

I went through all the XBL bindings, though it seems I could just use
GetBindingWithContent(), since according to:

  https://searchfox.org/mozilla-central/rev/55da592d85c2baf8d8818010c41d9738c97013d2/dom/xbl/nsXBLBinding.cpp#615

We don't allow multiple bindings to contribute anon content. Anyway it was the
same amount of code...

Comment 2

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 9004512 [details]
Skip less nodes when reporting memory, and report ShadowRoot's StyleSheets.

Boris Zbarsky [:bzbarsky, bz on IRC] has approved the revision.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2f49db02e5f6
Skip less nodes when reporting memory, and report ShadowRoot's StyleSheets. r=bzbarsky

Comment 4

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/2f49db02e5f6