From 759bfbb572db2c0389744965cc654e3e762a8172 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 14 Mar 2022 20:31:57 +0100
Subject: [PATCH] LibWeb: Use StyleComputer::invalidate_rule_cache() directly
 everywhere

Get rid of the old, roundabout way of invalidating the rule cache by
incrementing the StyleSheetList "generation".

Instead, when something wants to invalidate the rule cache, just have it
directly invalidate the rule cache. This makes it much easier to see
what's happening anyway.
---
 Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp  | 2 +-
 Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp  | 4 ++--
 Userland/Libraries/LibWeb/CSS/StyleComputer.cpp  | 4 +---
 Userland/Libraries/LibWeb/CSS/StyleComputer.h    | 1 -
 Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp | 4 ++--
 Userland/Libraries/LibWeb/CSS/StyleSheetList.h   | 3 ---
 6 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
index 6789443b5f8..c088d6030dc 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
@@ -85,7 +85,7 @@ void CSSImportRule::resource_did_load()
 
     m_style_sheet = move(sheet);
 
-    m_document->style_sheets().bump_generation();
+    m_document->style_computer().invalidate_rule_cache();
     m_document->invalidate_style();
 }
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
index 7ec8a5248e8..b44a87eb7ec 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
@@ -42,7 +42,7 @@ DOM::ExceptionOr<unsigned> CSSStyleSheet::insert_rule(StringView rule, unsigned
 
     if (!result.is_exception()) {
         if (m_style_sheet_list) {
-            m_style_sheet_list->bump_generation();
+            m_style_sheet_list->document().style_computer().invalidate_rule_cache();
             m_style_sheet_list->document().invalidate_style();
         }
     }
@@ -61,7 +61,7 @@ DOM::ExceptionOr<void> CSSStyleSheet::delete_rule(unsigned index)
     auto result = m_rules->remove_a_css_rule(index);
     if (!result.is_exception()) {
         if (m_style_sheet_list) {
-            m_style_sheet_list->bump_generation();
+            m_style_sheet_list->document().style_computer().invalidate_rule_cache();
             m_style_sheet_list->document().invalidate_style();
         }
     }
diff --git a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
index cd4561ee5d2..01425724abf 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -1071,7 +1071,7 @@ bool PropertyDependencyNode::has_cycles()
 
 void StyleComputer::build_rule_cache_if_needed() const
 {
-    if (m_rule_cache && m_rule_cache->generation == m_document.style_sheets().generation())
+    if (m_rule_cache)
         return;
     const_cast<StyleComputer&>(*this).build_rule_cache();
 }
@@ -1146,8 +1146,6 @@ void StyleComputer::build_rule_cache()
         dbgln("        Other: {}", m_rule_cache->other_rules.size());
         dbgln("        Total: {}", num_class_rules + num_id_rules + num_tag_name_rules + m_rule_cache->other_rules.size());
     }
-
-    m_rule_cache->generation = m_document.style_sheets().generation();
 }
 
 void StyleComputer::invalidate_rule_cache()
diff --git a/Userland/Libraries/LibWeb/CSS/StyleComputer.h b/Userland/Libraries/LibWeb/CSS/StyleComputer.h
index 6a1e3976a7d..2c688b3cc2d 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleComputer.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleComputer.h
@@ -104,7 +104,6 @@ private:
         HashMap<FlyString, Vector<MatchingRule>> rules_by_tag_name;
         HashMap<Selector::PseudoElement, Vector<MatchingRule>> rules_by_pseudo_element;
         Vector<MatchingRule> other_rules;
-        int generation { 0 };
     };
     OwnPtr<RuleCache> m_rule_cache;
 };
diff --git a/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp b/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
index 23d6dd96d60..a43ab4711a9 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
@@ -15,7 +15,7 @@ void StyleSheetList::add_sheet(NonnullRefPtr<CSSStyleSheet> sheet)
     sheet->set_style_sheet_list({}, this);
     m_sheets.append(move(sheet));
 
-    ++m_generation;
+    m_document.style_computer().invalidate_rule_cache();
     m_document.invalidate_style();
 }
 
@@ -24,7 +24,7 @@ void StyleSheetList::remove_sheet(CSSStyleSheet& sheet)
     sheet.set_style_sheet_list({}, nullptr);
     m_sheets.remove_first_matching([&](auto& entry) { return &*entry == &sheet; });
 
-    ++m_generation;
+    m_document.style_computer().invalidate_rule_cache();
     m_document.invalidate_style();
 }
 
diff --git a/Userland/Libraries/LibWeb/CSS/StyleSheetList.h b/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
index 70eb9157387..0fe931becee 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
@@ -43,9 +43,6 @@ public:
 
     bool is_supported_property_index(u32) const;
 
-    int generation() const { return m_generation; }
-    void bump_generation() { ++m_generation; }
-
     DOM::Document& document() { return m_document; }
     DOM::Document const& document() const { return m_document; }