Sets up the basic infrastructure for the audio node graph and
implements the AudioNode `connect()` method with its related overides.
AudioNodes store vectors of AudioNodeConnections and
AudioParamConnections to represent links between nodes.
Instead, porting over all users to use the newly created
Origin::create_opaque factory function. This also requires porting
over some users of Origin to avoid default construction.
As part of the effort of removing the default constructor of
Origin, since document has the origin set after construction,
port Document's origin over to an Optional<Origin>.
This exposes that we were never setting the origin of the document
during fragment parsing. For now, to maintain previous behaviour,
let's explicitly set it to an opaque origin.
All other viewport-related dimensions are referenced to by 'viewport',
so let's rename the member that stores the viewport size to prevent
further confusion.
Corresponds to d3effb701c
What a "fixed position container" is isn't clear to me, and we don't
seem to use that elsewhere, so I've left the steps using that as FIXMEs
for now.
There's no test coverage for this in WPT yet and I'm not confident
enough in the specific behaviour to write one myself. So, waiting on
https://github.com/web-platform-tests/wpt/issues/53214
For every invocation of `::before_paint()` and `::after_paint()`, we
would reach into the node's computed values to determine its visibility.
Let's just do this once during construction of the paintable instead,
since this was showing up in profiles.
In `StackingContext::paint_descendants()`, we don't need to obtain the
computed values nor the Z-index of a child unless certain other
conditions are true. Let these conditions short-circuit before actually
reaching into the computed values, which shows up in profiles.
`Element::ordinal_value` is called for every `li` element in
a list (ul, ol, menu).
Before:
`ordinal_value` iterates through all of the children of the list
owner. It is called once for each element: complexity $O(n^2)$.
After:
- Save the result of the first calculation in `m_ordinal_value`
then return it in subsequent calls.
- Tree modifications are intercepted and trigger invalidation
of the first node's `m_ordinal_value`:
- insert_before
- append
- remove
Results in noticeable performance improvement rendering' large
lists: from 20s to 4s for 20K elements.
Before:
`is<HTMLOLListElement>` and other similar calls in this commit
are resolved to `dynamic_cast`, which incurs runtime overhead
for resolving the type. The Performance hit becomes apparent
when rendering large lists. Callgrind analysis points to a
significant performance hit from calls to `is<...>` in
`Element::list_owner`.
Reference: Michael Gibbs and Bjarne Stroustrup (2006) Fast dynamic
casting. Softw. Pract. Exper. 2006; 36:139–156
After:
Implement inline `fast_is` virtual method that immediately
resolves the type. Results in noticeable performance improvement
2x-ish for lists with 20K entries.
Bonus: Convert starting value for LI elements to signed integer
The spec requires the start attribute and starting value to be
"integer". Firefox and Chrome support a negative start attribute.
FIXME: At the time of this PR, about 134 other objects resolve
`is<...>` to `dynamic_cast`. It may be a good idea to coordinate
similar changes to at least [some of] the ones that my have impact
on performance (maybe open a new issue?).
The spec assumes that we only store values against expanded longhands,
there are however limited circumstances where we store against
shorthands directly in addition to the expanded longhands. For example
if the value of the shorthand is unresolved we store an
UnresolvedStyleValue against the shorthand directly and a
PendingSubstitutionStyleValue against each of the longhands.
This commit updates the logic so that in the case we serialize a
shorthand directly we should also mark it's longhands as serialized to
avoid serializing them separately.
This also avoids the scenario where we tried to create and serialize a
ShorthandStyleValue with PendingSubstitutionStyleValue longhands, so we
can remove the check and related FIXME for that.
Fixes at least three WPT test that were previously timing out:
- html/semantics/embedded-content/media-elements/error-codes/error.html
- html/semantics/embedded-content/media-elements/location-of-the-media-resource/currentSrc.html
- html/semantics/embedded-content/the-video-element/video_crash_empty_src.html
