Lazy Parse CSS

third_party/WebKit/Source/core/css/StyleRule.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2005, 2006, 2008, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 190 matching lines @@
     rule->setParentRule(parentRule);
   return rule;
 }
 
 unsigned StyleRule::averageSizeInBytes() {
   return sizeof(StyleRule) + sizeof(CSSSelector) +
          StylePropertySet::averageSizeInBytes();
 }
 
 StyleRule::StyleRule(CSSSelectorList selectorList, StylePropertySet* properties)
-    : StyleRuleBase(Style), m_properties(properties) {
-  m_selectorList = std::move(selectorList);
+    : StyleRuleBase(Style),
+      m_selectorList(std::move(selectorList)),
+      m_properties(properties) {}
+
+StyleRule::StyleRule(CSSSelectorList selectorList,
+                     CSSLazyPropertyParser* lazyPropertyParser)
+    : StyleRuleBase(Style),
+      m_selectorList(std::move(selectorList)),
+      m_lazyPropertyParser(lazyPropertyParser) {}
+
+const StylePropertySet& StyleRule::properties() const {
+  if (!m_properties) {
+    m_properties = m_lazyPropertyParser->parseProperties();
+    m_lazyPropertyParser.clear();
+  }
+  return *m_properties;
 }
 
 StyleRule::StyleRule(const StyleRule& o)
     : StyleRuleBase(o),
-      m_properties(o.m_properties->mutableCopy()),
-      m_selectorList(o.m_selectorList.copy()) {}
+      m_selectorList(o.m_selectorList.copy()),
+      m_properties(o.properties().mutableCopy()) {}
 
 StyleRule::~StyleRule() {}
 
 MutableStylePropertySet& StyleRule::mutableProperties() {
-  if (!m_properties->isMutable())
+  // Ensure m_properties is initialized.
+  if (!properties().isMutable())
     m_properties = m_properties->mutableCopy();
   return *toMutableStylePropertySet(m_properties.get());
 }
 
+bool StyleRule::propertiesHaveFailedOrCanceledSubresources() const {
+  return m_properties && m_properties->hasFailedOrCanceledSubresources();
+}
+
+bool StyleRule::shouldConsiderForMatchingRules(bool includeEmptyRules) const {
+  // Consider all non-empty property sets if parsing has not been deferred.
+  // Otherwise, consider all StyleRules with non-null deferred closures.
+  return includeEmptyRules || !(m_properties && m_properties->isEmpty());

[esprehn, 2016/10/24 21:20:20]

run demorgans

includeEmptyRules || !m_properties || ! m_properties->isEmpty();

[Charlie Harrison, 2016/10/25 15:56:55]

Done.

+}
+
 DEFINE_TRACE_AFTER_DISPATCH(StyleRule) {
   visitor->trace(m_properties);
+  visitor->trace(m_lazyPropertyParser);
   StyleRuleBase::traceAfterDispatch(visitor);
 }
 
 StyleRulePage::StyleRulePage(CSSSelectorList selectorList,
                              StylePropertySet* properties)
     : StyleRuleBase(Page),
       m_properties(properties),
       m_selectorList(std::move(selectorList)) {}
 
 StyleRulePage::StyleRulePage(const StyleRulePage& o)
@@ skipping 98 matching lines @@
     m_properties = m_properties->mutableCopy();
   return *toMutableStylePropertySet(m_properties);
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(StyleRuleViewport) {
   visitor->trace(m_properties);
   StyleRuleBase::traceAfterDispatch(visitor);
 }
 
 }  // namespace blink