Changeset 230396 in webkit

Timestamp:

Apr 9, 2018 3:52:43 AM (6 years ago)

Author:

Carlos Garcia Campos

Message:

Merge r229288 - Don't invalidate all children when doing insertion/deletion in presence of backward positional selectors
​https://bugs.webkit.org/show_bug.cgi?id=183325
<rdar://problem/38134480>

Reviewed by Zalan Bujtas.

It is sufficient to invalidate siblings before the mutation point.

• dom/Element.cpp:

(WebCore::checkForSiblingStyleChanges):

We already do sibling walk in the case of forwards positional rules and sibling combinators. The work
done here is insignifant compared to cost of overinvalidating.

Location:

releases/WebKitGTK/webkit-2.20/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• dom/Element.cpp (modified) (1 diff)

releases/WebKitGTK/webkit-2.20/Source/WebCore/ChangeLog

@@ +1 @@
+2018-03-05  Antti Koivisto  <antti@apple.com>
+
+        Don't invalidate all children when doing insertion/deletion in presence of backward positional selectors
+        https://bugs.webkit.org/show_bug.cgi?id=183325
+        <rdar://problem/38134480>
+
+        Reviewed by Zalan Bujtas.
+
+        It is sufficient to invalidate siblings before the mutation point.
+
+        * dom/Element.cpp:
+        (WebCore::checkForSiblingStyleChanges):
+
+        We already do sibling walk in the case of forwards positional rules and sibling combinators. The work
+        done here is insignifant compared to cost of overinvalidating.
+
 2018-03-03  Said Abou-Hallawa  <sabouhallawa@apple.com>
 

releases/WebKitGTK/webkit-2.20/Source/WebCore/dom/Element.cpp

@@ -2078 +2078 @@
     // We have to invalidate everything following the insertion point in the forward case, and everything before the insertion point in the
     // backward case.
-    // |afterChange| is 0 in the parser callback case, so we won't do any work for the forward case if we don't have to.
-    // For performance reasons we just mark the parent node as changed, since we don't want to make childrenChanged O(n^2) by crawling all our kids
-    // here.  recalcStyle will then force a walk of the children when it sees that this has happened.
-    if (parent.childrenAffectedByBackwardPositionalRules() && elementBeforeChange)
-        parent.invalidateStyleForSubtree();
+    if (parent.childrenAffectedByBackwardPositionalRules()) {
+        for (auto* previous = elementBeforeChange; previous; previous = previous->previousElementSibling())
+            previous->invalidateStyleForSubtree();
+    }
 }