Lazy Parse CSS

third_party/WebKit/Source/core/css/parser/CSSParserImpl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CSSParserImpl_h
 #define CSSParserImpl_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/css/CSSProperty.h"
 #include "core/css/CSSPropertySourceData.h"
@@ skipping 22 matching lines @@
 class StyleRuleViewport;
 class StyleSheetContents;
 class ImmutableStylePropertySet;
 class Element;
 class MutableStylePropertySet;
 
 class CSSParserImpl {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(CSSParserImpl);
 public:
-    CSSParserImpl(const CSSParserContext&, StyleSheetContents* = nullptr);
+    CSSParserImpl(const CSSParserContext&, StyleSheetContents* = nullptr, bool deferPropertyParsing = false);
 
     enum AllowedRulesType {
         // As per css-syntax, css-cascade and css-namespaces, @charset rules
         // must come first, followed by @import then @namespace.
         // AllowImportRules actually means we allow @import and any rules thay
         // may follow it, i.e. @namespace rules and regular rules.
         // AllowCharsetRules and AllowNamespaceRules behave similarly.
         AllowCharsetRules,
         AllowImportRules,
         AllowNamespaceRules,
         RegularRules,
         KeyframeRules,
         ApplyRules, // For @apply inside style rules
         NoRules, // For parsing at-rules inside declaration lists
     };
 
     static bool parseValue(MutableStylePropertySet*, CSSPropertyID, const String&, bool important, const CSSParserContext&);
     static bool parseVariableValue(MutableStylePropertySet*, const AtomicString& propertyName, const String&, bool important, const CSSParserContext&);
     static ImmutableStylePropertySet* parseInlineStyleDeclaration(const String&, Element*);
     static bool parseDeclarationList(MutableStylePropertySet*, const String&, const CSSParserContext&);
     static StyleRuleBase* parseRule(const String&, const CSSParserContext&, StyleSheetContents*, AllowedRulesType);
-    static void parseStyleSheet(const String&, const CSSParserContext&, StyleSheetContents*);
+    static void parseStyleSheet(const String&, const CSSParserContext&, StyleSheetContents*, bool deferPropertyParsing = false);
     static CSSSelectorList parsePageSelector(CSSParserTokenRange, StyleSheetContents*);
 
     static ImmutableStylePropertySet* parseCustomPropertySet(CSSParserTokenRange);
 
     static std::unique_ptr<Vector<double>> parseKeyframeKeyList(const String&);
 
     bool supportsDeclaration(CSSParserTokenRange&);
 
     static void parseDeclarationListForInspector(const String&, const CSSParserContext&, CSSParserObserver&);
     static void parseStyleSheetForInspector(const String&, const CSSParserContext&, StyleSheetContents*, CSSParserObserver&);
@@ skipping 28 matching lines @@
     StyleRuleKeyframe* consumeKeyframeStyleRule(CSSParserTokenRange prelude, CSSParserTokenRange block);
     StyleRule* consumeStyleRule(CSSParserTokenRange prelude, CSSParserTokenRange block);
 
     void consumeDeclarationList(CSSParserTokenRange, StyleRule::RuleType);
     void consumeDeclaration(CSSParserTokenRange, StyleRule::RuleType);
     void consumeDeclarationValue(CSSParserTokenRange, CSSPropertyID, bool important, StyleRule::RuleType);
     void consumeVariableValue(CSSParserTokenRange, const AtomicString& propertyName, bool important);
 
     static std::unique_ptr<Vector<double>> consumeKeyframeKeyList(CSSParserTokenRange);
 
+    static std::unique_ptr<DeferredPropertiesClosure> createDeferredPropertiesClosure(CSSParserTokenRange, const CSSParserContext&, UseCounter*);
+
+    static StylePropertySet* parseDeclarationListForLazyStyle(Vector<CSSParserToken>, const CSSParserContext*, UseCounter*);
+
+    static bool shouldLazilyParseProperties(const CSSSelectorList& selectors);
+
     // FIXME: Can we build StylePropertySets directly?
     // FIXME: Investigate using a smaller inline buffer
     HeapVector<CSSProperty, 256> m_parsedProperties;
     const CSSParserContext& m_context;
 
     Member<StyleSheetContents> m_styleSheet;
 
     // For the inspector
     CSSParserObserverWrapper* m_observerWrapper;
+
+    bool m_deferPropertyParsing = false;

[Timothy Loh, 2016/09/28 02:01:44]

Not sure "= false" does anything here.

 };
 
 } // namespace blink
 
 #endif // CSSParserImpl_h