Source/WebCore/dom/DocumentOrderedMap.h

/*
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 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#pragma once

#include <wtf/HashMap.h>
#include <wtf/HashSet.h>
#include <wtf/Vector.h>
#include <wtf/text/AtomicStringImpl.h>

namespace WebCore {

class Element;
class HTMLImageElement;
class HTMLLabelElement;
class HTMLMapElement;
class TreeScope;

class DocumentOrderedMap {
    WTF_MAKE_FAST_ALLOCATED;
public:
    void add(const AtomicStringImpl&, Element&, const TreeScope&);
    void remove(const AtomicStringImpl&, Element&);
    void clear();

    bool contains(const AtomicStringImpl&) const;
    bool containsSingle(const AtomicStringImpl&) const;
    bool containsMultiple(const AtomicStringImpl&) const;

    // concrete instantiations of the get<>() method template
    Element* getElementById(const AtomicStringImpl&, const TreeScope&) const;
    Element* getElementByName(const AtomicStringImpl&, const TreeScope&) const;
    HTMLMapElement* getElementByMapName(const AtomicStringImpl&, const TreeScope&) const;
    HTMLImageElement* getElementByUsemap(const AtomicStringImpl&, const TreeScope&) const;
    HTMLLabelElement* getElementByLabelForAttribute(const AtomicStringImpl&, const TreeScope&) const;
    Element* getElementByWindowNamedItem(const AtomicStringImpl&, const TreeScope&) const;
    Element* getElementByDocumentNamedItem(const AtomicStringImpl&, const TreeScope&) const;

    const Vector<Element*>* getAllElementsById(const AtomicStringImpl&, const TreeScope&) const;

private:
    template <typename KeyMatchingFunction>
    Element* get(const AtomicStringImpl&, const TreeScope&, const KeyMatchingFunction&) const;

    struct MapEntry {
        MapEntry() { }
        explicit MapEntry(Element* firstElement)
            : element(firstElement)
            , count(1)
        { }

        Element* element { nullptr };
        unsigned count { 0 };
        Vector<Element*> orderedList;
#if !ASSERT_DISABLED || ENABLE(SECURITY_ASSERTIONS)
        HashSet<Element*> registeredElements;
#endif
    };

    typedef HashMap<const AtomicStringImpl*, MapEntry> Map;

    mutable Map m_map;
};

inline bool DocumentOrderedMap::containsSingle(const AtomicStringImpl& id) const
{
    auto it = m_map.find(&id);
    return it != m_map.end() && it->value.count == 1;
}

inline bool DocumentOrderedMap::contains(const AtomicStringImpl& id) const
{
    return m_map.contains(&id);
}

inline bool DocumentOrderedMap::containsMultiple(const AtomicStringImpl& id) const
{
    auto it = m_map.find(&id);
    return it != m_map.end() && it->value.count > 1;
}

} // namespace WebCore