Source/WebCore/css/CSSSelectorList.cpp

/*
 * Copyright (C) 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "CSSSelectorList.h"

#include "CSSParserValues.h"

namespace WebCore {

static CSSSelector* const freedSelectorArrayMarker = reinterpret_cast<CSSSelector*>(0xbbadbeef);

CSSSelectorList::~CSSSelectorList() 
{
    deleteSelectors();
}
    
void CSSSelectorList::adopt(CSSSelectorList& list)
{
    deleteSelectors();
    m_selectorArray = list.m_selectorArray;
    list.m_selectorArray = 0;
}

void CSSSelectorList::adoptSelectorVector(Vector<OwnPtr<CSSParserSelector> >& selectorVector)
{
    deleteSelectors();
    const size_t vectorSize = selectorVector.size();
    size_t flattenedSize = 0;
    for (size_t i = 0; i < vectorSize; ++i) {        
        for (CSSParserSelector* selector = selectorVector[i].get(); selector; selector = selector->tagHistory())
            ++flattenedSize;
    }
    ASSERT(flattenedSize);
    if (flattenedSize == 1) {
        m_selectorArray = selectorVector[0]->releaseSelector().leakPtr();
        m_selectorArray->setLastInSelectorList();
        ASSERT(m_selectorArray->isLastInTagHistory());
        selectorVector.shrink(0);
        return;
    }
    m_selectorArray = reinterpret_cast<CSSSelector*>(fastMalloc(sizeof(CSSSelector) * flattenedSize));
    size_t arrayIndex = 0;
    for (size_t i = 0; i < vectorSize; ++i) {
        CSSParserSelector* current = selectorVector[i].get();
        while (current) {
            OwnPtr<CSSSelector> selector = current->releaseSelector();
            current = current->tagHistory();
            move(selector.release(), &m_selectorArray[arrayIndex]);
            ASSERT(!m_selectorArray[arrayIndex].isLastInSelectorList());
            if (current)
                m_selectorArray[arrayIndex].setNotLastInTagHistory();
            ++arrayIndex;
        }
        ASSERT(m_selectorArray[arrayIndex - 1].isLastInTagHistory());
    }
    ASSERT(flattenedSize == arrayIndex);
    m_selectorArray[arrayIndex - 1].setLastInSelectorList();
    selectorVector.shrink(0);
}

void CSSSelectorList::deleteSelectors()
{
    if (!m_selectorArray)
        return;

    // FIXME: Remove once http://webkit.org/b/56124 is fixed.
    if (m_selectorArray == freedSelectorArrayMarker)
        CRASH();

    // We had two cases in adoptSelectVector. The fast case of a 1 element
    // vector took the CSSSelector directly, which was allocated with new.
    // The second case we allocated a new fastMalloc buffer, which should be
    // freed with fastFree, and the destructors called manually.
    CSSSelector* s = m_selectorArray;
    bool done = s->isLastInSelectorList();
    if (done)
        delete s;
    else {
        while (1) {
            s->~CSSSelector();
            if (done)
                break;
            ++s;
            done = s->isLastInSelectorList();
        }
        fastFree(m_selectorArray);
    }

    m_selectorArray = freedSelectorArrayMarker;
}


template <typename Functor>
static bool forEachTagSelector(Functor& functor, CSSSelector* selector)
{
    ASSERT(selector);

    do {
        if (functor(selector))
            return true;
        if (CSSSelectorList* selectorList = selector->selectorList()) {
            for (CSSSelector* subSelector = selectorList->first(); subSelector; subSelector = CSSSelectorList::next(subSelector)) {
                if (forEachTagSelector(functor, subSelector))
                    return true;
            }
        }
    } while ((selector = selector->tagHistory()));

    return false;
}

template <typename Functor>
static bool forEachSelector(Functor& functor, const CSSSelectorList* selectorList)
{
    for (CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(selector)) {
        if (forEachTagSelector(functor, selector))
            return true;
    }

    return false;
}

class SelectorNeedsNamespaceResolutionFunctor {
public:
    bool operator()(CSSSelector* selector)
    {
        if (selector->hasTag() && selector->tag().prefix() != nullAtom && selector->tag().prefix() != starAtom)
            return true;
        if (selector->hasAttribute() && selector->attribute().prefix() != nullAtom && selector->attribute().prefix() != starAtom)
            return true;
        return false;
    }
};

bool CSSSelectorList::selectorsNeedNamespaceResolution()
{
    SelectorNeedsNamespaceResolutionFunctor functor;
    return forEachSelector(functor, this);
}

class SelectorHasUnknownPseudoElementFunctor {
public:
    bool operator()(CSSSelector* selector)
    {
        return selector->isUnknownPseudoElement();
    }
};

bool CSSSelectorList::hasUnknownPseudoElements() const
{
    SelectorHasUnknownPseudoElementFunctor functor;
    return forEachSelector(functor, this);
}



} // namespace WebCore