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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

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

namespace WebCore {

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

void CSSSelectorList::adoptSelectorVector(Vector<CSSSelector*>& selectorVector)
{
    deleteSelectors();
    const size_t size = selectorVector.size();
    ASSERT(size);
    if (size == 1) {
        m_selectorArray = selectorVector[0];
        m_selectorArray->setLastInSelectorList();
        selectorVector.shrink(0);
        return;
    }
    m_selectorArray = reinterpret_cast<CSSSelector*>(fastMalloc(sizeof(CSSSelector) * selectorVector.size()));
    for (size_t i = 0; i < size; ++i) {
        memcpy(&m_selectorArray[i], selectorVector[i], sizeof(CSSSelector));
        // We want to free the memory (which was allocated with new), but we
        // don't want the destructor to run since it will affect the copy
        // we've just made. In theory this is undefined, but operator delete
        // is only defined taking a void*, so in practice it should be ok.
        delete reinterpret_cast<char*>(selectorVector[i]);
        ASSERT(!m_selectorArray[i].isLastInSelectorList());
    }
    m_selectorArray[size - 1].setLastInSelectorList();
    selectorVector.shrink(0);
}

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

    // 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);
    }
}

}