This commit adds hooks to the Servo style traversal to avoid traversing all the
DOM for every restyle. Additionally it changes the behavior of the dirty flag to
be propagated top down, to prevent extra overhead when an element is dirtied.
This commit doesn't aim to change the behavior on Servo just yet, since Servo does extra job when dirtying the node related with DOM revision counters that might be necessary.
CC @asajeffrey for the DOM revision counters stuff. When a node is dirty, do all its descendants really need to increment the revision counter, or is this an unintended effect? My intuition is that this is hurting performance quite a lot for servo.
r? @bholley
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- [x] `./mach build -d` does not report any errors
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Source-Repo: https://github.com/servo/servo
Source-Revision: 944d371b8f0e72f6aa5465be38c0c8daeab66127
Background:
The changes to Servo code to support Stylo began in the `selectors` crate with making pseudo-elements generic, defined be the user, so that different users (such as Servo and Gecko/Stylo) could have a different set of pseudo-elements supported and parsed. Adding a trait makes sense there since `selectors` is in its own repository and has others users (or at least [one](https://github.com/SimonSapin/kuchiki)).
Then we kind of kept going with the same pattern and added a bunch of traits in the `style` crate to make everything generic, allowing Servo and Gecko/Stylo to do things differently. But we’ve also added a `gecko` Cargo feature to do conditional compilation, at first to enable or disable some CSS properties and values in the Mako templates. Since we’re doing conditional compilation anyway, it’s often easier and simpler to do it more (with `#[cfg(feature = "gecko")]` and `#[cfg(feature = "servo")]`) that to keep adding traits and making everything generic. When a type is generic, any method that we want to call on it needs to be part of some trait.
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The first several commits move some code around, mostly from `geckolib` to `style` (with `#[cfg(feature = "gecko")]`) but otherwise don’t change much.
The following commits remove some traits and many type parameters through the `style` crate, replacing them with pairs of conditionally-compiled API-compatible items (types, methods, …).
Simplifying code is nice to make it more maintainable, but this is motivated by another change described in https://github.com/servo/servo/pull/12391#issuecomment-232183942. (Porting Servo for that change proved difficult because some code in the `style` crate was becoming generic over `String` vs `Atom`, and this PR will help make that concrete. That change, in turn, is motivated by removing geckolib’s `[replace]` override for string-cache, in order to enable using a single Cargo "workspace" in this repository.)
r? @bholley
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- [x] These changes fix #__ (github issue number if applicable).
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Source-Repo: https://github.com/servo/servo
Source-Revision: 2d01d41a506bcbc7f26a2284b9f42390d6ef96ab
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The bulk of this is adding cargo features to make derived implementations of `heapsize` and `serde` traits optional.
"Almost" because `std::intrinsics::discriminant_value` is currently unstable and doesn’t have any stable replacement that I know of. For now, this PR conditionally replaces it with `unimplemented!()`.
r? @nox
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- [x] These changes <s>fix</s> are part of #11815 (github issue number if applicable).
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- [ ] There are tests for these changes OR
- [x] These changes do not <s>require tests</s> *have tests yet* because that requires https://github.com/servo/servo/issues/11806, but I still want to land this before it bitrots. (Tests should check that the build succeeds with a stable compiler.)
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Source-Repo: https://github.com/servo/servo
Source-Revision: 0fb5d634a007f3d0424f95569ac3f83d500d054c
This allows geckolib to pass gecko style structs and have the style system write to them directly, provided we implement all the traits.
Source-Repo: https://github.com/servo/servo
Source-Revision: 605842f193aedc1151ab38a99c49f693c76e5cf3
This allows, among other things, having different implementations for parsing pseudo{elements, classes} in both `ports/geckolib` and in servo.
Source-Repo: https://github.com/servo/servo
Source-Revision: c11844cbf28054784c8d65781cff20045d8ee48b
This is a step towards removing the dependency of stylo on layout/.
This PR depends on #9004.
Source-Repo: https://github.com/servo/servo
Source-Revision: 0f5c614609fd8867a9e7c27b8a398ea7d877c714
