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6 commits

Author SHA1 Message Date
Martin Robinson
573663d502
layout: Correct damage propagation and style repair for repaint-only layout (#37004)
When making last-minute changes to the repaint-only layout pass, damage
propagation was broken, meaning that full layout was always done. This
change fixes that, meaning that times in the `blaster.html` test case
now reflect those described in the original commit message from #36978.

In addition, some style repair is now fixed:
- `InlineFormattingContext`s now keep a `SharedInlineStyles` for the
root of the IFC
    which is updated during style repair.
 - `BlockFormattingContext`s now properly update their style.

These changes are verified by turning on repaint only layout for more
properties
in Stylo via servo/stylo#183.

Testing: Manual performance testing via `blaster.html`.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
2025-05-19 10:17:49 +00:00
Martin Robinson
8808f9a468
layout: Add a repaint-only incremental layout mode (#36978)
This change adds the simplest kind of incremental layout. When Servo
detects that all style changes only require a repaint, only run stacking
context tree and WebRender display list generation. This means that
these kind of restyles do not need a re-layout. Instead, the existing
box and fragment trees will be used and the styles of damaged nodes will
be updated in their box and fragment tree nodes.

This requires a new style repair DOM traversal for nodes that have had
their style damaged. In addition, careful accounting of all the places
where we store style must happen in order ot update those styles.

Testing: This is covered by existing WPT tests as it should not change
observable behavior.

We have created a test case which shows a 50% speedup when run
in Servo, even though there still a long way to go to match the speed
of other browsers:
https://gist.github.com/mrobinson/44ec87d028c0198917a7715a06dd98a0

Co-authored-by: Oriol Brufau <obrufau@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
2025-05-12 17:03:50 +00:00
Martin Robinson
a0dd2c1beb
layout: Share styles to inline box children via SharedInlineStyles (#36896)
`TextRun`s use their parent style to render. Previously, these styles
were cloned and stored directly in the box tree `TextRun` and resulting
`TextFragment`s. This presents a problem for incremental layout.
Wrapping the style in another layer of shared ownership and mutability
will allow updating all `TextFragment`s during repaint-only incremental
layout by simply updating the box tree styles of the original text
parents.

This adds a new set of borrows when accessing text styles, but also
makes it so that during box tree block construction
`InlineFormattingContext`s are created lazily and now
`InlineFormattingContextBuilder::finish` consumes the builder, making
the API make a bit more sense. This should also improve performance of
box tree block construction slightly.

Testing: This should not change observable behavior and thus is covered
by existing WPT tests.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
2025-05-12 09:38:50 +00:00
Martin Robinson
348eede37b
layout: Store shared styles for table backgrounds in SharedBackgroundStyle (#36893)
Table cells share background styles with their track and track group
boxes. When a track and track group style is repaired, this new data
structure will allow reparing the style of the cell `Fragment`s without
having to lay the table out again or walk through `Fragment`s and
individually repair their background styles.

Testing: This doesn't change behavior and is thus tested by existing
WPT tests.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
2025-05-07 11:44:59 +00:00
Josh Matthews
878d595035
script: Measure stored layout data memory usage. (#36664)
We previously ignored the opaque layout data field inside each node when
measuring a DOM node's memory usage. While some of the reachable memory
was accounted for by measuring the layout's box tree, measuring it via
the node ensures that we don't miss anything. Since there are often Arc
values involved, this means that the layout-thread box tree measurements
now look quite small, while reported JS heap usage has increased.

Testing: Manually compared about:memory for servo.org.

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>
2025-04-24 12:01:51 +00:00
Martin Robinson
7787cab521
layout: Combine layout_2020 and layout_thread_2020 into a crate called layout (#36613)
Now that legacy layout has been removed, the name `layout_2020` doesn't
make much sense any longer, also it's 2025 now for better or worse. The
split between the "layout thread" and "layout" also doesn't make as much
sense since layout doesn't run on it's own thread. There's a possibility
that it will in the future, but that should be something that the user
of the crate controls rather than layout iself.

This is part of the larger layout interface cleanup and optimization
that
@Looriool and I are doing.

Testing: Covered by existing tests as this is just code movement.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
2025-04-19 10:17:03 +00:00
Renamed from components/layout_2020/table/mod.rs (Browse further)