Allow the embedder to override all preferences #309
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Loirooriol
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…ences" Bumps Stylo to servo/stylo#309 For consistency with Gecko, Stylo renames the `layout.threads` pref to `layout.css.stylo-threads`. But it seems fine to keep `--layout_threads` as the command argument. stylo-prefs
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| pub fn get_bool(&self, key: &str, default: bool) -> bool { | ||
| let prefs = self.bool_prefs.read().expect("RwLock is poisoned"); | ||
| *prefs.get(key).unwrap_or(&false) | ||
| *prefs.get(key).unwrap_or(&default) |
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It's unfortunate that the API now must take the default value rather than being able to look up the default value itself.
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Yes, but static_prefs::pref!() gets the default automatically, and that's the API that we should use. E.g. Gecko doesn't have style_config::get_bool() at all.
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| pub trait Getter { | ||
| fn get(key: &str, default: Self) -> Self; | ||
| } | ||
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| impl Getter for bool { | ||
| fn get(key: &str, default: Self) -> Self { | ||
| get_bool(key, default) | ||
| } | ||
| } | ||
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| impl Getter for i32 { | ||
| fn get(key: &str, default: Self) -> Self { | ||
| get_i32(key, default) | ||
| } | ||
| } | ||
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Where are these used? I find it bizarre to add a get() method on i32 and bool. Maybe they can be removed?
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I'm using this in
#[macro_export]
macro_rules! pref {
($string:tt) => {
style_config::Getter::get($string, $crate::default_value!($string))
};
}The reason is that static_prefs::pref!() can access both booleans and numbers, so I needed a trait for the specialization.
Previously, Stylo was hard-coding the value for various preferences. Now Stylo will only define the default value for the preferences, but if the embedder sets a different value, the latter will be used instead. For example, `layout.css.marker.restricted` should definitely default to true (according to the spec), but Servo should be allowed to set it to false e.g. for debugging purposes, or in specific tests. For consistent defaults, this replaces most `style_config::get_bool()` with `static_prefs::pref!()`. And the pref `layout.threads` gets renamed to `layout.css.stylo-threads`, in order to share code with Gecko. Signed-off-by: Oriol Brufau <[email protected]>
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Previously, Stylo was hard-coding the value for various preferences. Now Stylo will only define the default value for the preferences, but if the embedder sets a different value, the latter will be used instead.
For example, when not set otherwise,
layout.threadsused to default to 0 as any other i32 pref. However, this was a bad default, it meant that embedders like Blitz were running Stylo single-threaded. With this change we can make it default to -1, while still allowing Servo to set it to 3.For consistent defaults, this replaces most
style_config::get_bool()withstatic_prefs::pref!().Servo PR: servo/servo#42491