Bug 2019254 Part 1 - Use indices in CSSContainerRule glue for conditions. r=firefox-style-system-reviewers,emilio

AlaskanEmily · AlaskanEmily · commit ca67bf8a591b · 2026-04-01T18:27:22.000Z
Differential Revision: https://phabricator.services.mozilla.com/D290611
diff --git a/layout/style/CSSContainerRule.cpp b/layout/style/CSSContainerRule.cpp
@@ -57,18 +57,28 @@ void CSSContainerRule::GetCssText(nsACString& aCssText) const {
 }
 
 void CSSContainerRule::GetContainerName(nsACString& aName) const {
-  Servo_ContainerRule_GetContainerName(mRawRule, &aName);
+  const size_t n = Servo_ContainerRule_GetConditionsLength(mRawRule);
+  if (n == 1) {
+    Servo_ContainerRule_GetContainerName(mRawRule, 0, &aName);
+  }
 }
 
 void CSSContainerRule::GetContainerQuery(nsACString& aQuery) const {
-  Servo_ContainerRule_GetContainerQuery(mRawRule, &aQuery);
+  const size_t n = Servo_ContainerRule_GetConditionsLength(mRawRule);
+  if (n == 1) {
+    Servo_ContainerRule_GetContainerQuery(mRawRule, 0, &aQuery);
+  }
 }
 
 void CSSContainerRule::GetConditions(
     nsTArray<CSSContainerCondition>& aConditions) const {
-  auto& condition = *aConditions.AppendElement();
-  GetContainerName(condition.mName);
-  GetContainerQuery(condition.mQuery);
+  const size_t n = Servo_ContainerRule_GetConditionsLength(mRawRule);
+  aConditions.SetCapacity(n);
+  for (size_t i = 0; i < n; i++) {
+    CSSContainerCondition& condition = *aConditions.AppendElement();
+    Servo_ContainerRule_GetContainerName(mRawRule, i, &condition.mName);
+    Servo_ContainerRule_GetContainerQuery(mRawRule, i, &condition.mQuery);
+  }
 }
 
 Element* CSSContainerRule::QueryContainerFor(const Element& aElement) const {
diff --git a/servo/ports/geckolib/glue.rs b/servo/ports/geckolib/glue.rs
@@ -3457,38 +3457,48 @@ pub extern "C" fn Servo_ContainerRule_GetConditionText(
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ContainerRule_GetContainerQuery(
+pub extern "C" fn Servo_ContainerRule_GetConditionsLength(rule: &ContainerRule) -> usize {
+    rule.conditions.0.len()
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_ContainerRule_GetContainerName(
     rule: &ContainerRule,
+    i: usize,
     result: &mut nsACString,
 ) {
-    if let Some(condition) = rule.conditions.0.first().and_then(|c| c.query_condition()){
-        condition.to_css(&mut CssWriter::new(result)).unwrap();
+    if let Some(condition) = rule.conditions.0.get(i) {
+        let name = condition.name();
+        if !name.is_none() {
+            name.to_css(&mut CssWriter::new(result)).unwrap();
+        }
     }
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ContainerRule_QueryContainerFor(
+pub extern "C" fn Servo_ContainerRule_GetContainerQuery(
     rule: &ContainerRule,
-    element: &RawGeckoElement,
-) -> *const RawGeckoElement {
-    debug_assert_eq!(rule.conditions.0.len(), 1);
-    let condition = rule.conditions.0.first().unwrap();
-    condition
-        .find_container(GeckoElement(element), None)
-        .map_or(ptr::null(), |result| result.element.0)
+    i: usize,
+    result: &mut nsACString,
+) {
+    if let Some(condition) = rule.conditions.0.get(i) {
+        if let Some(condition) = condition.query_condition() {
+            condition.to_css(&mut CssWriter::new(result)).unwrap();
+        }
+    }
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ContainerRule_GetContainerName(
+pub extern "C" fn Servo_ContainerRule_QueryContainerFor(
     rule: &ContainerRule,
-    result: &mut nsACString,
-) {
-    if let Some(condition) = rule.conditions.0.first() {
-        let name = condition.name();
-        if !name.is_none() {
-            name.to_css(&mut CssWriter::new(result)).unwrap();
+    element: &RawGeckoElement,
+) -> *const RawGeckoElement {
+    for condition in rule.conditions.0.iter() {
+        if let Some(result) = condition.find_container(GeckoElement(element), None) {
+            return result.element.0;
         }
     }
+    ptr::null()
 }
 
 #[no_mangle]
