Per RFC 9111, we're allowed to cache HTTP responses that don't have a
"Cache-Control" header, provided they do have an "Expires" header.
This lets us cache JavaScript resources on https://x.com/ and makes
it load much faster when cached.
There is no need to recreate this each time we need it when we can
instead create it once and then reuse it.
This is stop-gap since we should resolve colors to their computed forms
as part of StyleComputer::compute_properties
Reduces time spent in ColorResolutionContext::for_layout_node from ~1.1%
to ~0.1% when loading
https://en.wikipedia.org/wiki/2023_in_American_television
We don't need to iterate every property in start_needed_transitions,
only those that appear in transition-property or have an existing
transition
Reduces the time spent in start_needed_transitions from ~5% to ~0.03%
when loading https://en.wikipedia.org/wiki/2023_in_American_television
By doing this in computed properties rather than InlineLevelIterator we
only do it once per element rather than once per text fragment.
Reduces runtime of this process from ~15% to ~0.2% when loading
https://en.wikipedia.org/wiki/2023_in_American_television
We simplify these at style computation time so there is no need to
maintain them as {Number|Length}OrCalculated
Reduces the time spent in `Length::ResolutionContext::for_layout_node`
from 3.3% to 0.4% when loading
https://en.wikipedia.org/wiki/2023_in_American_television
The lookahead lexer used by next_token() no longer needs to be kept
alive, since tokens created by Parser::next_token() now have any string
views guaranteed safe by the fact that they point into the one true
SourceCode provided by whoever set up the lexer.
This moves the responsibility of setting up a SourceCode object to the
users of JS::Lexer.
This means Lexer and Parser are free to use string views into the
SourceCode internally while working.
It also means Lexer no longer has to think about anything other than
UTF-16 (or ASCII) inputs. So the unit test for parsing various invalid
UTF-8 sequences is deleted here.
Identifier tokens are stored as Utf16FlyString, so there's no need to
forcibly keep them alive through this mechanism. (It was useful when
tokens only had string views.)
The spec defines a generic list interfaces that we can reuse. Currently
we only have SVGTransformList, but we will need this to add
SVGNumberList as well.
LibURL parses "localhost:8000" as a URL with a scheme of "localhost" and
basename of "8000". Similar to "mailto:" URLs. We then drop the URL as
having an invalid scheme.
Let's explicitly check for such localhost URLs here and prepend a valid
scheme, as it is a bit of a special case.
When an element has `display: contents` and it gets marked for a layout
tree rebuild, we actually have to mark its parent for rebuild as well.
The structure of the parent (and siblings) may change depending on how
the `display: contents` element changes (e.g position, display, etc.)
