...instead of specially handling JS::Completion.
This makes it possible for LibWeb/LibJS to have full control over how
these things are made, stored, and visited (whenever).
Fixes an issue where we couldn't roundtrip a JS exception through Wasm.
There's a specific (and thankfully very common!) scenario where we can
actually skip calculating the automatic minimum size for flex items.
In single-line (no wrapping) flex containers, if the sum of all item
flex base sizes is <= the flex container's main size, we know that
none of the items will be shrunk by the layout algorithm.
And so for any flex item with definite main size AND automatic minimum
main size, we can treat the automatic minimum size as 0.
We were calculating the fit-content cross size and then throwing it
away and doing it again. You might think this wasn't so bad since
fit-content relies on cacheable intrinsic sizes *buuuuut* since we're
actually modifying the constraints for the second call, we were indeed
doing completely wasted work here.
For unscrolled viewports (already at 0, 0), we can short-circuit here
and avoid doing a synchronous relayout of the page.
This avoids a bunch of synchronous layouts on Speedometer3's NewsSite
(Nuxt version) subtests.
For unscrolled elements (already at 0, 0) that aren't eligible to be the
Document.scrollingElement, we can short-circuit here and avoid doing a
synchronous relayout of the page.
This avoids a bunch of synchronous layouts on Speedometer3's NewsSite
subtests.
Instead of using the first font from the FontCascadeList for all glyphs
in a text, we perform a text shaping process that finds a suitable font
for each glyph and returns a list of glyph runs, where each glyph run
represents consecutive glyphs using the same font.
Canvas text painting needs to support per-glyph font fallbacks, which
means we can't hand over responsibility for text shaping to Skia and
instead need to extract glyph paths from our own shaped GlyphRun.
Instead of indiscriminately clearing the cache for all anonymous boxes,
we now only clear it for those that were generated by a non-anonymous
box in need of layout update.
This increases the cache hit rate and allows us to avoid more work.
These elements are quite special, so let's treat them like we do for
substantial CSS display changes and rebuild the layout tree starting
from the parent element instead of self.
Before this change, we were going through the chain of base classes for
each IDL interface object and having them set the prototype to their
prototype.
Instead of doing that, reorder things so that we set the right prototype
immediately in Foo::initialize(), and then don't bother in all the base
class overrides.
This knocks off a ~1% profile item on Speedometer 3.
Many elements never end up needing this string, so instead of eagerly
generating it in the Element constructor, let's defer it until someone
actually requests it.
Knocks off a ~1% profile item on Speedometer3's jQuery test.
Instead of using the more generic define_native_accessor() here,
we poke directly at indexed property storage for the parameter map.
We can also construct the NativeFunction objects directly, without
giving them names like "get 0" etc, since these are not observable
by userspace.
Finally, by using default property attributes (not observable anyway),
we get simple indexed storage instead of generic (hash map) storage.
Instead, let JS::NativeFunction store the AK::Function directly, and
take care of conservatively marking its captured data.
This avoids an extra GC allocation for every JS::NativeFunction.
This will cause an exception to be thrown if user attempts to read from
the response stream of a failed request.
This is unfortunately not testable in CI. It requires a network response
(i.e. not a file:// URL). We also cannot import relevant WPT tests; they
exercise this condition with a python-generated response.
The basic idea is that style sheets can block script execution under
some circumstances. With this commit, we now handle the simplest cases
where a parser-inserted link element gets to download its style sheet
before script execution continues.
This improves performance on Speedometer 3 where JavaScript APIs that
depend on layout results (like Element.scrollIntoView()) would get
called too early (before the relevant CSS was downloaded), and so we'd
perform premature layout work. This work then had to be redone after
downloading the CSS anyway, wasting time.
Note that our Text/input/link-re-enable-crash.html test had to be
tweaked after these changes, since it relied on the old, incorrect,
behavior where scripts would run before downloading CSS.
No code now relies on using URL's valid state.
A URL can still be _technically_ invalid through use of the URL
constructor or by directly changing URL fields.
However, all URLs should be constructed through the URL parser,
and we should ideally be getting rid of the default constructor
at some stage.
Also, any code which is manually setting URL fields need to be
aware that this is full of pitfalls since there are many different
forms of canonicalization which is bypassed by not going through
the URL parser.
Creating a URL should almost always go through the URLParser to
handle all of the small edge cases involved. This reduces the
need for URL valid state.
