Source/core/css/invalidation/InvalidationSet.h

/*
 * Copyright (C) 2014 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 *
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#ifndef InvalidationSet_h
#define InvalidationSet_h

#include "core/CoreExport.h"
#include "platform/heap/Handle.h"
#include "wtf/Forward.h"
#include "wtf/HashSet.h"
#include "wtf/RefCounted.h"
#include "wtf/RefPtr.h"
#include "wtf/text/AtomicStringHash.h"
#include "wtf/text/StringHash.h"

namespace blink {

class Element;
class TracedValue;

// Tracks data to determine which elements of a DOM subtree need to have style
// recalculated.
class CORE_EXPORT InvalidationSet final : public RefCountedWillBeGarbageCollected<InvalidationSet> {
    WTF_MAKE_NONCOPYABLE(InvalidationSet);
public:
    static PassRefPtrWillBeRawPtr<InvalidationSet> create()
    {
        return adoptRefWillBeNoop(new InvalidationSet);
    }

    static void cacheTracingFlag();

    bool invalidatesElement(Element&) const;

    void combine(const InvalidationSet& other);

    void addClass(const AtomicString& className);
    void addId(const AtomicString& id);
    void addTagName(const AtomicString& tagName);
    void addAttribute(const AtomicString& attributeLocalName);

    void setWholeSubtreeInvalid();
    bool wholeSubtreeInvalid() const { return m_allDescendantsMightBeInvalid; }

    void setInvalidatesSelf() { m_invalidatesSelf = true; }
    bool invalidatesSelf() const { return m_invalidatesSelf; }

    void setTreeBoundaryCrossing() { m_treeBoundaryCrossing = true; }
    bool treeBoundaryCrossing() const { return m_treeBoundaryCrossing; }

    void setInsertionPointCrossing() { m_insertionPointCrossing = true; }
    bool insertionPointCrossing() const { return m_insertionPointCrossing; }

    void setCustomPseudoInvalid() { m_customPseudoInvalid = true; }
    bool customPseudoInvalid() const { return m_customPseudoInvalid; }

    bool isEmpty() const { return !m_classes && !m_ids && !m_tagNames && !m_attributes && !m_customPseudoInvalid; }

    DECLARE_TRACE();

    void toTracedValue(TracedValue*) const;

#ifndef NDEBUG
    void show() const;
#endif

private:
    InvalidationSet();

    WillBeHeapHashSet<AtomicString>& ensureClassSet();
    WillBeHeapHashSet<AtomicString>& ensureIdSet();
    WillBeHeapHashSet<AtomicString>& ensureTagNameSet();
    WillBeHeapHashSet<AtomicString>& ensureAttributeSet();

    // FIXME: optimize this if it becomes a memory issue.
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString>> m_classes;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString>> m_ids;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString>> m_tagNames;
    OwnPtrWillBeMember<WillBeHeapHashSet<AtomicString>> m_attributes;

    // If true, all descendants might be invalidated, so a full subtree recalc is required.
    unsigned m_allDescendantsMightBeInvalid : 1;

    // If true, the element itself is invalid.
    unsigned m_invalidatesSelf : 1;

    // If true, all descendants which are custom pseudo elements must be invalidated.
    unsigned m_customPseudoInvalid : 1;

    // If true, the invalidation must traverse into ShadowRoots with this set.
    unsigned m_treeBoundaryCrossing : 1;

    // If true, insertion point descendants must be invalidated.
    unsigned m_insertionPointCrossing : 1;
};

} // namespace blink

#endif // InvalidationSet_h