tor-browser

commit ed534cda355fda623fda7f0eebd82d3a753620bc
parent 09d64cb5afc90a01d0dd6cba6e491015350621d1
Author: Emilio Cobos Álvarez <emilio@crisal.io>
Date:   Mon, 20 Oct 2025 15:05:48 +0000

Bug 1995304 - Simplify and clean-up stylesheet collection iteration. r=Oriol

I want the iter_mut() methods to fix
https://github.com/servo/servo/pull/40024.

But we can simplify this a little bit nowadays to avoid duplicating a
lot of code.

Differential Revision: https://phabricator.services.mozilla.com/D269226

Diffstat:
M
servo/components/style/stylesheet_set.rs
 | 
112
++++++++++++++++++++-----------------------------------------------------------

1 file changed, 28 insertions(+), 84 deletions(-)
diff --git a/servo/components/style/stylesheet_set.rs b/servo/components/style/stylesheet_set.rs
@@ -9,10 +9,8 @@ use crate::invalidation::stylesheets::{RuleChangeKind, StylesheetInvalidationSet
 use crate::media_queries::Device;
 use crate::selector_parser::SnapshotMap;
 use crate::shared_lock::SharedRwLockReadGuard;
-use crate::stylesheets::{
-    CssRule, Origin, OriginSet, OriginSetIterator, PerOrigin, StylesheetInDocument,
-};
-use std::{mem, slice};
+use crate::stylesheets::{CssRule, Origin, OriginSet, PerOrigin, StylesheetInDocument};
+use std::mem;
 
 /// Entry for a StylesheetSet.
 #[derive(MallocSizeOf)]
@@ -39,75 +37,6 @@ where
     }
 }
 
-/// A iterator over the stylesheets of a list of entries in the StylesheetSet.
-pub struct StylesheetCollectionIterator<'a, S>(slice::Iter<'a, StylesheetSetEntry<S>>)
-where
-    S: StylesheetInDocument + PartialEq + 'static;
-
-impl<'a, S> Clone for StylesheetCollectionIterator<'a, S>
-where
-    S: StylesheetInDocument + PartialEq + 'static,
-{
-    fn clone(&self) -> Self {
-        StylesheetCollectionIterator(self.0.clone())
-    }
-}
-
-impl<'a, S> Iterator for StylesheetCollectionIterator<'a, S>
-where
-    S: StylesheetInDocument + PartialEq + 'static,
-{
-    type Item = &'a S;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.0.next().map(|entry| &entry.sheet)
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        self.0.size_hint()
-    }
-}
-
-/// An iterator over the flattened view of the stylesheet collections.
-#[derive(Clone)]
-pub struct StylesheetIterator<'a, S>
-where
-    S: StylesheetInDocument + PartialEq + 'static,
-{
-    origins: OriginSetIterator,
-    collections: &'a PerOrigin<SheetCollection<S>>,
-    current: Option<(Origin, StylesheetCollectionIterator<'a, S>)>,
-}
-
-impl<'a, S> Iterator for StylesheetIterator<'a, S>
-where
-    S: StylesheetInDocument + PartialEq + 'static,
-{
-    type Item = (&'a S, Origin);
-
-    fn next(&mut self) -> Option<Self::Item> {
-        loop {
-            if self.current.is_none() {
-                let next_origin = self.origins.next()?;
-
-                self.current = Some((
-                    next_origin,
-                    self.collections.borrow_for_origin(&next_origin).iter(),
-                ));
-            }
-
-            {
-                let (origin, ref mut iter) = *self.current.as_mut().unwrap();
-                if let Some(s) = iter.next() {
-                    return Some((s, origin));
-                }
-            }
-
-            self.current = None;
-        }
-    }
-}
-
 /// The validity of the data in a given cascade origin.
 #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Ord, PartialEq, PartialOrd)]
 pub enum DataValidity {
@@ -166,8 +95,8 @@ where
     /// Returns the list of stylesheets for `origin`.
     ///
     /// Only used for UA sheets.
-    pub fn origin_sheets(&mut self, origin: Origin) -> StylesheetCollectionIterator<'_, S> {
-        self.collections.borrow_mut_for_origin(&origin).iter()
+    pub fn origin_sheets(&self, origin: Origin) -> impl Iterator<Item = &S> {
+        self.collections.borrow_for_origin(&origin).iter()
     }
 
     /// Returns whether any DOM invalidations were processed as a result of the
@@ -367,8 +296,13 @@ where
     }
 
     /// Returns an iterator over the current list of stylesheets.
-    fn iter(&self) -> StylesheetCollectionIterator<'_, S> {
-        StylesheetCollectionIterator(self.entries.iter())
+    fn iter(&self) -> impl Iterator<Item = &S> {
+        self.entries.iter().map(|e| &e.sheet)
+    }
+
+    /// Returns a mutable iterator over the current list of stylesheets.
+    fn iter_mut(&mut self) -> impl Iterator<Item = &mut S> {
+        self.entries.iter_mut().map(|e| &mut e.sheet)
     }
 
     fn flush(&mut self) -> SheetCollectionFlusher<'_, S> {
@@ -597,12 +531,17 @@ where
     }
 
     /// Return an iterator over the flattened view of all the stylesheets.
-    pub fn iter(&self) -> StylesheetIterator<'_, S> {
-        StylesheetIterator {
-            origins: OriginSet::all().iter_origins(),
-            collections: &self.collections,
-            current: None,
-        }
+    pub fn iter(&self) -> impl Iterator<Item = (&S, Origin)> {
+        self.collections
+            .iter_origins()
+            .flat_map(|(c, o)| c.iter().map(move |s| (s, o)))
+    }
+
+    /// Return an iterator over the flattened view of all the stylesheets, mutably.
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = (&mut S, Origin)> {
+        self.collections
+            .iter_mut_origins()
+            .flat_map(|(c, o)| c.iter_mut().map(move |s| (s, o)))
     }
 
     /// Mark the stylesheets for the specified origin as dirty, because
@@ -681,10 +620,15 @@ where
     sheet_set_methods!("AuthorStylesheetSet");
 
     /// Iterate over the list of stylesheets.
-    pub fn iter(&self) -> StylesheetCollectionIterator<'_, S> {
+    pub fn iter(&self) -> impl Iterator<Item = &S> {
         self.collection.iter()
     }
 
+    /// Returns a mutable iterator over the current list of stylesheets.
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut S> {
+        self.collection.iter_mut()
+    }
+
     /// Mark the sheet set dirty, as appropriate.
     pub fn force_dirty(&mut self) {
         self.invalidations.invalidate_fully();