1509226 - Avoid allocations to define clips

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Description

[Matt Woodrow (:mattwoodrow)]

Both versions of DefineClipChain use an nsTArray to collect the clips to be defined, which means at least 2 allocations for every new clip we encounter.

The two types (wr::WrClipId and size_t) are the same thing in-memory, so we should be able to use a single vector, and AutoTArray should stop us from allocating in all but the most extreme cases.

Doing this removes a few % from WR command building time.

Comment 1

[Jeff Muizelaar [:jrmuizel]]

I filed something like this in bug 1506172.

Comment 2

[Matt Woodrow (:mattwoodrow)]

Uploading my patch anyway, since it's done.

I think we could land it now, and do the conversion to the properly exported rust type in 1506172 once the clip cleanup is done. Or we could just wait, it's not a huge performance difference. I don't mind.

Comment 3

[Matt Woodrow (:mattwoodrow)]

Attachment: Bug 1509226 - Avoid allocations to serialize clips. r?jrmuizel

MozReview-Commit-ID: CetmS5cZCMP

Depends on D12720

Comment 4

[Jeff Muizelaar [:jrmuizel]]

I'd rather use the same WrClipId in both places instead of asserting that size_t is the same type.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d6509279d52e
Avoid allocations to serialize clips. r=jrmuizel

Comment 6

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/d6509279d52e