Source/core/dom/TreeScopeAdopter.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
#include "config.h"
#include "core/dom/TreeScopeAdopter.h"

#include "core/dom/Attr.h"
#include "core/dom/Document.h"
#include "core/dom/NodeRareData.h"
#include "core/dom/NodeTraversal.h"
#include "core/dom/shadow/ElementShadow.h"
#include "core/dom/shadow/ShadowRoot.h"

namespace WebCore {

void TreeScopeAdopter::moveTreeToNewScope(Node& root) const
{
    ASSERT(needsScopeChange());

    m_oldScope.guardRef();

    // If an element is moved from a document and then eventually back again the collection cache for
    // that element may contain stale data as changes made to it will have updated the DOMTreeVersion
    // of the document it was moved to. By increasing the DOMTreeVersion of the donating document here
    // we ensure that the collection cache will be invalidated as needed when the element is moved back.
    Document* oldDocument = m_oldScope.documentScope();
    ASSERT(oldDocument);
    Document* newDocument = m_newScope.documentScope();
    bool willMoveToNewDocument = oldDocument != newDocument;
    if (willMoveToNewDocument)
        oldDocument->incDOMTreeVersion();

    for (Node* node = &root; node; node = NodeTraversal::next(*node, &root)) {
        updateTreeScope(*node);

        if (willMoveToNewDocument)
            moveNodeToNewDocument(*node, *oldDocument, newDocument);
        else if (node->hasRareData()) {
            NodeRareData* rareData = node->rareData();
            if (rareData->nodeLists())
                rareData->nodeLists()->adoptTreeScope();
        }

        if (!node->isElementNode())
            continue;

        if (node->hasSyntheticAttrChildNodes()) {
            const Vector<RefPtr<Attr> >& attrs = toElement(node)->attrNodeList();
            for (unsigned i = 0; i < attrs.size(); ++i)
                moveTreeToNewScope(*attrs[i]);
        }

        for (ShadowRoot* shadow = node->youngestShadowRoot(); shadow; shadow = shadow->olderShadowRoot()) {
            shadow->setParentTreeScope(&m_newScope);
            if (willMoveToNewDocument)
                moveTreeToNewDocument(*shadow, *oldDocument, newDocument);
        }
    }

    m_oldScope.guardDeref();
}

void TreeScopeAdopter::moveTreeToNewDocument(Node& root, Document& oldDocument, Document* newDocument) const
{
    for (Node* node = &root; node; node = NodeTraversal::next(*node, &root)) {
        moveNodeToNewDocument(*node, oldDocument, newDocument);
        for (ShadowRoot* shadow = node->youngestShadowRoot(); shadow; shadow = shadow->olderShadowRoot())
            moveTreeToNewDocument(*shadow, oldDocument, newDocument);
    }
}

#ifndef NDEBUG
static bool didMoveToNewDocumentWasCalled = false;
static Document* oldDocumentDidMoveToNewDocumentWasCalledWith = 0;

void TreeScopeAdopter::ensureDidMoveToNewDocumentWasCalled(Document& oldDocument)
{
    ASSERT(!didMoveToNewDocumentWasCalled);
    ASSERT_UNUSED(oldDocument, oldDocument == oldDocumentDidMoveToNewDocumentWasCalledWith);
    didMoveToNewDocumentWasCalled = true;
}
#endif

inline void TreeScopeAdopter::updateTreeScope(Node& node) const
{
    ASSERT(!node.isTreeScope());
    ASSERT(node.treeScope() == m_oldScope);
    m_newScope.guardRef();
    m_oldScope.guardDeref();
    node.setTreeScope(&m_newScope);
}

inline void TreeScopeAdopter::moveNodeToNewDocument(Node& node, Document& oldDocument, Document* newDocument) const
{
    ASSERT(!node.inDocument() || oldDocument != newDocument);

    if (node.hasRareData()) {
        NodeRareData* rareData = node.rareData();
        if (rareData->nodeLists())
            rareData->nodeLists()->adoptDocument(&oldDocument, newDocument);
    }

    oldDocument.moveNodeIteratorsToNewDocument(&node, newDocument);

    if (node.isShadowRoot())
        toShadowRoot(node).setDocumentScope(newDocument);

#ifndef NDEBUG
    didMoveToNewDocumentWasCalled = false;
    oldDocumentDidMoveToNewDocumentWasCalledWith = &oldDocument;
#endif

    node.didMoveToNewDocument(oldDocument);
    ASSERT(didMoveToNewDocumentWasCalled);
}

}