http://www.robohornet.org gives a score of 101.36 on master, and 102.68 with this PR. The latter is slightly better, but probably within noise level. So it looks like this PR does not affect DOM performance.
This is expected since `Box::new` is defined as:
```rust
impl<T> Box<T> {
#[inline(always)]
pub fn new(x: T) -> Box<T> {
box x
}
}
```
With inlining, it should compile to the same as box syntax.
Source-Repo: https://github.com/servo/servo
Source-Revision: a9022be0c3e30249845ca5947ac0c0a6743c7991
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
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<!-- Please describe your changes on the following line: -->
I just changed the `prefix` parameters on the constructors of several HTML elements. The type now is `Option<Prefix>`. I also changed the sizes of the `sizeof.rs` unit test to match the new values.
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Source-Repo: https://github.com/servo/servo
Source-Revision: ed7686b42c02c5c1d769be952ef58b285f35a7f6
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : ade76a808b80fcbb1e011c0b6f7a29c37361559e
Previously, `string-cache` defined:
* An string-like `Atom` type,
* An `atom!("foo")` macro that expands to a value of that type, for a set of strings known at compile-time,
* A `struct Namespace(Atom);` type
* A `ns!(html)` macro that maps known prefixed to `Namespace` values with the corresponding namespace URL.
Adding a string to the static set required making a change to the `string-cache` crate.
With 0.3, the `Atom` type is now generic, with a type parameter that provides a set of static strings. We can have multiple such sets, defined in different crates. The `string_cache_codegen` crate, to be used in build scripts, generates code that defines such a set, a new atom type (a type alias for `Atom<_>` with the type parameter set), and an `atom!`-like macro.
The html5ever repository has a new `html5ever_atoms` crate that defines three such types: `Prefix`, `Namespace`, and `LocalName` (with respective `namespace_prefix!`, `namespace_url!`, and `local_name!` macros). It also defines the `ns!` macro like before.
This repository has a new `servo_atoms` crate in `components/atoms` that, for now, defines a single `Atom` type (and `atom!`) macro. (`servo_atoms::Atom` is defined as something like `type Atom = string_cache::Atom<ServoStaticStringSet>;`, so overall there’s now two types named `Atom`.)
In this PR, `servo_atoms::Atom` is used for everything else that was `string_cache::Atom` before. But more atom types can be defined as needed. Two reasons to do this are to auto-generate the set of static strings (I’m planning to do this for CSS property names, which is the motivation for this change), or to have the type system help us avoid mix up unrelated things (this is why we had a `Namespace` type ever before this change).
Introducing new types helped me find a bug: when creating a new attribute `dom::Element::set_style_attr`, would pass `Some(atom!("style"))` instead of `None` (now `Option<html5ever_atoms::Prefix>` instead of `Option<string_cache::Atom>`) to the `prefix` argument of `Attr::new`. I suppose the author of that code confused it with the `local_name` argument.
---
Note that Stylo is not affected by any of this. The `gecko_string_cache` module is unchanged, with a single `Atom` type. The `style` crate conditionally compiles `Prefix` and `LocalName` re-exports for that are both `gecko_string_cache::Atom` on stylo.
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Source-Repo: https://github.com/servo/servo
Source-Revision: 5b4cc9568dbd5c15e5d2fbc62719172f11566ffa
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minimal SVG element implementation
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Source-Repo: https://github.com/servo/servo
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