Changes function signatures to accept `ClipId`, `ExternalScrollId` and
`ScrollTreeNodeId` instead of `&ClipId`, `&ExternalScrollId` and
`&ScrollTreeNodeId`. This avoids several `&` and `*`.
Testing: not needed, no behavior change.
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
Measures the memory usage of the stacking context tree in the memory
report of the layout thread by adding `MallocSizeOf` to
`StackingContextTree` and all the types required for that. Also requires
adding `MallocSizeOf` to some webrender types.
Testing: Manually looked at about:memory
<img width="636" height="241" alt="image"
src="https://github.com/user-attachments/assets/6bf9d65a-0bf0-4a99-99b5-ddedba3269c1"
/>
Fixes: https://github.com/servo/servo/issues/38725
---------
Signed-off-by: Rahul Menon <menonrahul02@gmail.com>
In #18933, hit testing was moved from layout to WebRender. This presents
some issues. For instance, the DOM can change at the same time that hit
test is happening. This can mean that hit test returns references to
defunct DOM nodes, introducing memory safety issues. Currently, Servo
will try to ensure that the epochs used for testing and those recorded
in the DOM match, but this is not very reliable and has led to code that
retries failed hit tests.
This change reintroduces (8 years later) a layout hit tester and turns
it on for `document.elementFromPoint` and `document.elementsFromPoint`.
The idea is that this hit tester will gradually replace the majority of
the WebRender hit testing happening in the renderer.
Testing: This shouldn't really change the behavior hit testing, but it
seems to improve one WPT test.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Co-authored-by: kongbai1996 <1782765876@qq.com>
Previously, after a layout was finished (or skipped in the case of
repaint-only layout), both the stacking context tree and display list
were built. In the case of repaint-only layout, we should be able to
skip the reconstruction of the stacking context tree and only do display
list building.
This change does that, also generally cleaning and up and clarifying the
data structure used during this phase of layout. This opens up the
possibility of a new kind of incremental layout that does both repaint
and a rebuild of the stacking context tree.
On the blaster.html test case[^1], this reduces tightly-measured layout
time from ~45-50 milliseconds to ~25-30 milliseconds on my M3.
[^1]: https://gist.github.com/mrobinson/44ec87d028c0198917a7715a06dd98a0
Testing: There are currently no performance tests for layout. :( This
should
not modify the results of WPT tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
