By modeling it as a separate layer that behaves somewhat specially.
See https://github.com/w3c/csswg-drafts/issues/6872.
The remaining revert-layer tests that we fail are because either we
don't implement a feature (like @property) or because it's used in
keyframes (where revert is a bit unspecified and we have existing
issues with it).
Differential Revision: https://phabricator.services.mozilla.com/D133373
This patch looks bigger than it is, but it's mostly because
of plumbing.
To implement revert-layer we need not only the cascade origin of the
declaration, but the whole cascade level, plus also the layer order.
In order to do this, encapsulate these two things inside a 32-bit
`CascadePriority` struct and plumb it through the rule tree and so on.
This allows us to remove the packing and unpacking of CascadeLevel,
though I kept the ShadowCascadeOrder limit for now in case we need to
reintroduce it.
Fix `!important` behavior of layers while at it (implementing it in
`CascadeLevel::cmp`, spec quote included since it was tricky to find)
since some revert-layer tests were depending on it.
The style attribute test is failing now, but follow-up commit fixes
it, see spec issue.
In terms of the actual keyword implementation, it's sort of
straight-forward: We implement revert and revert-layer in a shared
way, by storing the cascade priority that reverted it.
Differential Revision: https://phabricator.services.mozilla.com/D133372
The bitfield approach worked when the layer order was in pre-order, but
the spec was changed to make it work like post-order and I don't think
there's a way to keep it working like that, so keep the layer order in a
separate data structure that we look up when going from Rule to
ApplicableDeclarationBlock.
This is just a vector index operation so hopefully shouldn't be too bad.
This patch intentionally regresses @keyframe handling to some extent,
since we need a bit more complicated approach and it seemed worth
implementing in a separate patch.
Depends on D129380
Differential Revision: https://phabricator.services.mozilla.com/D129381
Same, I want to land this separately to see if it affects
micro-benchmarks. If so, we might want to pack the layer order
_somewhere_ (though in this case I'm not sure where, tbh).
With this, layer rules should have an effect on the page. There are
a few things missing before being able to enable them:
* Fix nested layer order in some cases (when parent layers are declared
out of order, see the previous commit mentioning this).
* Some kind of OM representation, perhaps.
* Tests of course, which are coming in bug 1728722 and bug 1727276.
But this should be enough to allow playing with them.
Depends on D124337
Differential Revision: https://phabricator.services.mozilla.com/D124338
I didn't bother not shifting there. We need to load the whole thing and shift
for at least one of cascade level / shadow cascade order.
Callers of level() other than for_rule_tree are non-existent in release builds,
so we'd be doing the shift anyway. I can implement the same thing for
shadow_cascade_order too, but I don't think that optimization is measurable in
any way, either, the compiler should make the decision.
And just in case, the simpler version actually generated less instructions in:
https://play.rust-lang.org/?gist=ceadb0d3cbce4eeca76e4d9ab9a1c744&version=nightly
with the simple thing.
Bug: 1455032
Reviewed-by: heycam
MozReview-Commit-ID: 8xPBJmlcyKh
No cleaner ideas right now that carrying that counter around... Maybe a custom
type may be cleaner?
This makes ApplicableDeclarationBlock a bit bigger. I could probably try to make
the counter a 4 / 5-bit number or something and pack the counter there in the
SourceOrderAndCascadeLevel somehow...
But doesn't seem really worth the churn, and can be done as a followup in any
case. Let me know if you want to block on that.
Bug: 1454162
Reviewed-by: heycam
MozReview-Commit-ID: 1LdW9S4xA6f
Servo currently uses `heapsize`, but Stylo/Gecko use `malloc_size_of`.
`malloc_size_of` is better -- it handles various cases that `heapsize` does not
-- so this patch changes Servo to use `malloc_size_of`.
This patch makes the following changes to the `malloc_size_of` crate.
- Adds `MallocSizeOf` trait implementations for numerous types, some built-in
(e.g. `VecDeque`), some external and Servo-only (e.g. `string_cache`).
- Makes `enclosing_size_of_op` optional, because vanilla jemalloc doesn't
support that operation.
- For `HashSet`/`HashMap`, falls back to a computed estimate when
`enclosing_size_of_op` isn't available.
- Adds an extern "C" `malloc_size_of` function that does the actual heap
measurement; this is based on the same functions from the `heapsize` crate.
This patch makes the following changes elsewhere.
- Converts all the uses of `heapsize` to instead use `malloc_size_of`.
- Disables the "heapsize"/"heap_size" feature for the external crates that
provide it.
- Removes the `HeapSizeOf` implementation from `hashglobe`.
- Adds `ignore` annotations to a few `Rc`/`Arc`, because `malloc_size_of`
doesn't derive those types, unlike `heapsize`.
ServoStyleSetSizes now has two uses, one for the Stylist, and one for the UA
cache, and so the patch removes 'Stylist' from the field names.
Example output from about:memory:
> +----1,359,608 B (00.55%) -- layout
> | +----756,488 B (00.31%) -- style-sheet-cache [2]
> | +----393,968 B (00.16%) -- servo-ua-cache
> | | +--234,496 B (00.10%) -- element-and-pseudos-maps
> | | +---59,648 B (00.02%) -- revalidation-selectors
> | | +---58,320 B (00.02%) -- invalidation-map
> | | +---30,752 B (00.01%) -- other
> | | +---10,752 B (00.00%) -- precomputed-pseudos
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).
