Lazy Parse CSS

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

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2008, 2012, 2013 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef StyleRule_h
 #define StyleRule_h
 
 #include "core/CoreExport.h"
 #include "core/css/CSSSelectorList.h"
 #include "core/css/MediaList.h"
 #include "core/css/StylePropertySet.h"
+#include "core/css/parser/CSSParser.h"

[Timothy Loh, 2016/09/27 05:15:45]

This include isn't needed now :)

[Charlie Harrison, 2016/09/27 13:22:00]

Done.

 #include "platform/heap/Handle.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class CSSRule;
 class CSSStyleSheet;
 
 class CORE_EXPORT StyleRuleBase : public GarbageCollectedFinalized<StyleRuleBase> {
 public:
@@ skipping 51 matching lines @@
     unsigned m_type : 5;
 };
 
 class CORE_EXPORT StyleRule : public StyleRuleBase {
 public:
     // Adopts the selector list
     static StyleRule* create(CSSSelectorList selectorList, StylePropertySet* properties)
     {
         return new StyleRule(std::move(selectorList), properties);
     }
+    static StyleRule* createLazy(CSSSelectorList selectorList, std::unique_ptr<DeferredPropertiesClosure> deferredProperties)
+    {
+        return new StyleRule(std::move(selectorList), std::move(deferredProperties));
+    }
 
     ~StyleRule();
 
     const CSSSelectorList& selectorList() const { return m_selectorList; }
-    const StylePropertySet& properties() const { return *m_properties; }
+    const StylePropertySet& properties() const;
     MutableStylePropertySet& mutableProperties();
 
     void wrapperAdoptSelectorList(CSSSelectorList selectors) { m_selectorList = std::move(selectors); }
 
     StyleRule* copy() const { return new StyleRule(*this); }
 
     static unsigned averageSizeInBytes();
 
+    // Helper methods to avoid parsing lazy properties when not needed.
+    bool propertiesHaveFailedOrCanceledSubresources() const;
+    bool hasEmptyProperties() const;
+
     DECLARE_TRACE_AFTER_DISPATCH();
 
 private:
     StyleRule(CSSSelectorList, StylePropertySet*);
+    StyleRule(CSSSelectorList, std::unique_ptr<DeferredPropertiesClosure>);
     StyleRule(const StyleRule&);
 
-    Member<StylePropertySet> m_properties; // Cannot be null.
     CSSSelectorList m_selectorList;
+    mutable Member<StylePropertySet> m_properties;
+    mutable std::unique_ptr<DeferredPropertiesClosure> m_deferred;
 };
 
 class StyleRuleFontFace : public StyleRuleBase {
 public:
     static StyleRuleFontFace* create(StylePropertySet* properties)
     {
         return new StyleRuleFontFace(properties);
     }
 
     ~StyleRuleFontFace();
@@ skipping 139 matching lines @@
 DEFINE_STYLE_RULE_TYPE_CASTS(FontFace);
 DEFINE_STYLE_RULE_TYPE_CASTS(Page);
 DEFINE_STYLE_RULE_TYPE_CASTS(Media);
 DEFINE_STYLE_RULE_TYPE_CASTS(Supports);
 DEFINE_STYLE_RULE_TYPE_CASTS(Viewport);
 DEFINE_STYLE_RULE_TYPE_CASTS(Charset);
 
 } // namespace blink
 
 #endif // StyleRule_h