Source/core/dom/DocumentOrderedMap.cpp

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#include "config.h"
#include "core/dom/DocumentOrderedMap.h"

#include "HTMLNames.h"
#include "core/dom/Element.h"
#include "core/dom/ElementTraversal.h"
#include "core/dom/TreeScope.h"
#include "core/html/HTMLLabelElement.h"
#include "core/html/HTMLMapElement.h"

namespace WebCore {

using namespace HTMLNames;

inline bool keyMatchesId(StringImpl* key, Element* element)
{
    return element->getIdAttribute().impl() == key;
}

inline bool keyMatchesMapName(StringImpl* key, Element* element)
{
    return element->hasTagName(mapTag) && toHTMLMapElement(element)->getName().impl() == key;
}

inline bool keyMatchesLowercasedMapName(StringImpl* key, Element* element)
{
    return element->hasTagName(mapTag) && toHTMLMapElement(element)->getName().lower().impl() == key;
}

inline bool keyMatchesLabelForAttribute(StringImpl* key, Element* element)
{
    return isHTMLLabelElement(element) && element->getAttribute(forAttr).impl() == key;
}

void DocumentOrderedMap::clear()
{
    m_map.clear();
    m_duplicateCounts.clear();
}

void DocumentOrderedMap::add(StringImpl* key, Element* element)
{
    ASSERT(key);
    ASSERT(element);

    if (!m_duplicateCounts.contains(key)) {
        // Fast path. The key is not already in m_duplicateCounts, so we assume that it's
        // also not already in m_map and try to add it. If that add succeeds, we're done.
        Map::AddResult addResult = m_map.add(key, element);
        if (addResult.isNewEntry)
            return;

        // The add failed, so this key was already cached in m_map.
        // There are multiple elements with this key. Remove the m_map
        // cache for this key so get searches for it next time it is called.
        m_map.remove(addResult.iterator);
        m_duplicateCounts.add(key);
    } else {
        // There are multiple elements with this key. Remove the m_map
        // cache for this key so get will search for it next time it is called.
        Map::iterator cachedItem = m_map.find(key);
        if (cachedItem != m_map.end()) {
            m_map.remove(cachedItem);
            m_duplicateCounts.add(key);
        }
    }

    m_duplicateCounts.add(key);
}

void DocumentOrderedMap::remove(StringImpl* key, Element* element)
{
    ASSERT(key);
    ASSERT(element);

    Map::iterator cachedItem = m_map.find(key);
    if (cachedItem != m_map.end() && cachedItem->value == element)
        m_map.remove(cachedItem);
    else
        m_duplicateCounts.remove(key);
}

template<bool keyMatches(StringImpl*, Element*)>
inline Element* DocumentOrderedMap::get(StringImpl* key, const TreeScope* scope) const
{
    ASSERT(key);
    ASSERT(scope);

    Element* element = m_map.get(key);
    if (element)
        return element;

    if (m_duplicateCounts.contains(key)) {
        // We know there's at least one node that matches; iterate to find the first one.
        for (element = ElementTraversal::firstWithin(scope->rootNode()); element; element = ElementTraversal::next(element)) {
            if (!keyMatches(key, element))
                continue;
            m_duplicateCounts.remove(key);
            m_map.set(key, element);
            return element;
        }
        ASSERT_NOT_REACHED();
    }

    return 0;
}

Element* DocumentOrderedMap::getElementById(StringImpl* key, const TreeScope* scope) const
{
    return get<keyMatchesId>(key, scope);
}

Element* DocumentOrderedMap::getElementByMapName(StringImpl* key, const TreeScope* scope) const
{
    return get<keyMatchesMapName>(key, scope);
}

Element* DocumentOrderedMap::getElementByLowercasedMapName(StringImpl* key, const TreeScope* scope) const
{
    return get<keyMatchesLowercasedMapName>(key, scope);
}

Element* DocumentOrderedMap::getElementByLabelForAttribute(StringImpl* key, const TreeScope* scope) const
{
    return get<keyMatchesLabelForAttribute>(key, scope);
}

} // namespace WebCore