1591629 - No need to pass TransformData for all transform-like properties to compositor

Status: RESOLVED FIXED

(Core :: CSS Transitions and Animations, enhancement, P3)

Description

[Boris Chiou [:boris]]

We can reduce the usage of data we pass via IPC LayersMessages by

1. Use an individual struct for motion path data (i.e. MotionPathData). If there is no offset-*, we just set it Nothing(). (This may not have benefits on data usage because Maybe<> still allocate space it may need.) But still worth to do.
2. Don't pass TransformData and MotionPathData for all transform-like properties. (Note: All of them for the same transaction are the same). Maybe only pass it with the first animation property.
3. Maybe we can remove any potential duplicates from TransformData or MotionPathData. Or maybe not.

Comment 1

[Boris Chiou [:boris]]

Attachment: Bug 1591629 - Keep TransformData only in the first element when passing animation data through IPC.

The benefit are:

1. For the rest layers::Animations, their TransformData are Nothing(),
   so we can avoid any posisible copy.
2. In the compositor, PropertyAniamtionGroup uses UniquePtr to hold the
   TransformData in the first element, and the rest elements don't need
   to copy/allocalate memery for this duplicated data.

Comment 2

[Boris Chiou [:boris]]

Attachment: Bug 1591629 - Split TransformData into 2 parts - transform data and motion path data.

So we don't need to create motion path data if there is no offset-path style
and no animations of offset-path.

Comment 3

[Boris Chiou [:boris]]

Attachment: Bug 1591629 - Rename mozilla::MotionPathData as mozilla::ResolvedMotionPathData.

To avoid the ambiguous name because we also have layers::MotionPathData.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e9462ce8f669
Keep TransformData only in the first element when passing animation data through IPC. r=hiro
https://hg.mozilla.org/integration/autoland/rev/88869acebf28
Split TransformData into 2 parts - transform data and motion path data. r=hiro
https://hg.mozilla.org/integration/autoland/rev/3b89f8acd826
Rename mozilla::MotionPathData as mozilla::ResolvedMotionPathData. r=hiro

Comment 5

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/e9462ce8f669
https://hg.mozilla.org/mozilla-central/rev/88869acebf28
https://hg.mozilla.org/mozilla-central/rev/3b89f8acd826