It used to be this way because of lifetime issues (plus the shadow
datas were in RwLocks at some point IIRC). Now we guarantee that as long as the
element is away the cascade data is as well, so we don't need to thread it
around.
Differential Revision: https://phabricator.services.mozilla.com/D2768
Kinda tricky because :host only matches rules on the shadow root where the rules
come from. So we need to be careful during invalidation and style sharing.
I didn't use the non_ts_pseudo_class_list bits because as soon as we implement
the :host(..) bits we're going to need to special-case it anyway.
The general schema is the following:
* Rightmost featureless :host selectors are handled inserting them in the
host_rules hashmap. Note that we only insert featureless stuff there. We
could insert all of them and just filter during matching, but that's slightly
annoying.
* The other selectors, like non-featureless :host or what not, are added to the
normal cascade data. This is harmless, since the shadow host rules are never
matched against the host, so we know they'll just never match, and avoids
adding more special-cases.
* Featureless :host selectors to the left of a combinator are handled during
matching, in the special-case of next_element_for_combinator in selectors.
This prevents this from being more invasive, and keeps the usual fast path
slim, but it's a bit hard to match the spec and the implementation.
We could keep a copy of the SelectorIter instead in the matching context to
make the handling of featureless-ness explicit in match_non_ts_pseudo_class,
but we'd still need the special-case anyway, so I'm not fond of it.
* We take advantage of one thing that makes this sound. As you may have
noticed, if you had `root` element which is a ShadowRoot, and you matched
something like `div:host` against it, using a MatchingContext with
current_host == root, we'd incorrectly report a match. But this is impossible
due to the following constraints:
* Shadow root rules aren't matched against the host during styling (except
these featureless selectors).
* DOM APIs' current_host needs to be the _containing_ host, not the element
itself if you're a Shadow host.
Bug: 992245
Reviewed-by: xidorn
MozReview-Commit-ID: KayYNfTXb5h
This enables us to implement Element::has_css_layout_box() in a more
direct way, and also enables us to remove some of the existing more
specific queries.
Fixes#19811.
This is only useful to avoid restyling NAC subtrees, but _not_ for ::before or
::after, in most cases. These subrees are small, and reframing is also not too
common, so I don't think it warrants the complexity.
We already remove all change hints down the tree when finding a reframe hint
using ClearServoRestyleFromSubtree in ServoRestyleManager, so this is useless.
MozReview-Commit-ID: 1twx7iPt79x
This avoids threading the quirks mode and nth-index cache around, and prevents
having to thread even more arguments down for the querySelector stuff (at least
VisitedHandlingMode and the style scope).
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>
We only use it to get the quirks mode, and a shared style context is a pretty
heavy-weight struct.
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>
This patch makes the MallocSizeOf stuff in Stylo work more like the HeapSizeOf
stuff already in Servo, except better. In particular, it adds deriving support
for MallocSizeOf, which will make it easier to improve coverage.
The patch does the following.
- Combines servo/components/style/stylesheets/memory.rs and the heapsize crate
into a new crate, malloc_size_of.
- Forks the heapsize_derive crate, calling it malloc_size_of, so that
MallocSizeOf can be derived.
- Both the new crates have MIT/Apache licenses, like heapsize, in case they are
incorporated into heapsize in the future.
- Renames the methods within MallocSizeOf and the related traits so they are
more concise.
- Removes MallocSizeOfWithGuard.
- Adds `derive(MallocSizeOf)` to a lot of types, in some cases replacing an
equivalent or almost-equivalent hand-written implementation.
- Adds stuff so that Rc/Arc can be handled properly.
The patch provides FFI access to Gecko's SeenPtrs type from Rust, in
order to record what has already been measured when measuring Arcs. (The
SeenPtrs must be initialized on the Gecko side because the same table is
reused for measuring all Elements within a window, because Elements can
share ComputedValues.) I have confirmed with DMD that this is working
correctly.
The patch also introduces MallocSizeOfRepeats, which is like
MallocSizeOf but takes a SizeOfState, which holds a SeenPtrs table.
The alias is left there temporarilly and will be removed completely in a later commit where
also components/style/gecko/generated/structs_{debug|release}.rs are re-generated (they still
use the old alias).
