The style candidate cache had regressed a few times (see #12534), and my
intuition is that being able to disable all style sharing with a single rule in
the page is really unfortunate.
This commit redesigns the style sharing cache in order to be a optimistic cache,
but then reject candidates if they match different sibling-affecting selectors
in the page, for example.
So far the numbers have improved, but not so much as I'd wanted (~10%/20% of
non-incremental restyling time in general). The current implementation is really
dumb though (we recompute and re-match a lot of stuff), so we should be able to
optimise it quite a bit.
I have different ideas for improving it (that may or may not work), apart of the
low-hanging fruit like don't re-matching candidates all the time but I have to
measure the real impact.
Also, I need to verify it against try.
* Sections like `[dependencies.foo]` can be entries in a `[dependencies]`
section with the `{key = value}` syntax.
* Per-target dependencies can be expressed with more general `cfg(…)`
conditions instead of exact target triples:
https://github.com/rust-lang/cargo/pull/2328
Dirty elements whose selectors are affected by sibling changes
This fixes incremental layout of nodes that match pseudo-class selectors such as :first-child, :nth-child, :last-child, :first-of-type, etc. Fixes#8191 and other intermittent layout bugs.
This code is based on the following flags from Gecko:
https://hg.mozilla.org/mozilla-central/file/e1cf617a1f28/dom/base/nsINode.h#l134
Depends on servo/rust-selectors#71. r? @SimonSapin
There are a couple of TODO items in this commit, but I'd appreciate feedback on the general approach before I finish it up. (Also, if someone who knows more than I do could give some advice about atomic orderings...)
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WebRender is an experimental GPU accelerated rendering backend for Servo.
The WebRender backend can be specified by running Servo with the -w option (otherwise the default rendering backend will be used).
WebRender has many bugs, and missing features - but it is usable to browse most websites - please report any WebRender specific rendering bugs you encounter!
This commit refactors the style crate to be completely independent of
the actual implementation and pseudo-elements supported.
This also adds a gecko backend which introduces parsing for the
anonymous box pseudo-elements[1], although there's still no way of
querying them.
https://mxr.mozilla.org/mozilla-central/source/layout/style/nsCSSAnonBoxList.h
