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Diffstat (limited to 'src/xmlpatterns/iterators/qcachingiterator_p.h')
| -rw-r--r-- | src/xmlpatterns/iterators/qcachingiterator_p.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/xmlpatterns/iterators/qcachingiterator_p.h b/src/xmlpatterns/iterators/qcachingiterator_p.h new file mode 100644 index 0000000000..ebf5fda6a1 --- /dev/null +++ b/src/xmlpatterns/iterators/qcachingiterator_p.h @@ -0,0 +1,129 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtXmlPatterns module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists purely as an +// implementation detail. This header file may change from version to +// version without notice, or even be removed. +// +// We mean it. + +#ifndef Patternist_CachingIterator_H +#define Patternist_CachingIterator_H + +#include <QList> +#include <QVector> + +#include "qdynamiccontext_p.h" +#include "qitem_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +namespace QPatternist +{ + /** + * @short An QAbstractXmlForwardIterator that gets its item from a cache unless its empty, in + * which case it continues to populate the cache as well as deliver on its + * own from a source QAbstractXmlForwardIterator. + * + * @author Frans Englich <frans.fenglich@trolltech.com> + * @ingroup Patternist_iterators + */ + class CachingIterator : public Item::Iterator + { + public: + /** + * We always use the same cache cell so why don't we use it directly, + * instead of passing the slot and ItemSequenceCacheCell::Vector to + * this class? Because the GenericDynamicContext might decide to resize + * the vector and that would invalidate the reference. + * + * We intentionally pass in a non-const reference here. + */ + CachingIterator(ItemSequenceCacheCell::Vector &cacheCells, + const VariableSlotID slot, + const DynamicContext::Ptr &context); + + virtual Item next(); + virtual Item current() const; + virtual xsInteger position() const; + virtual Item::Iterator::Ptr copy() const; + + private: + Item m_current; + xsInteger m_position; + + /** + * This variable cannot be called m_slot, because + * /usr/include/sys/sysmacros.h on hpuxi-acc defines it. + */ + const VariableSlotID m_varSlot; + + /** + * We don't use the context. We only keep a reference such that it + * doesn't get deleted, and m_cacheCells starts to dangle. + */ + const DynamicContext::Ptr m_context; + + /** + * We intentionally store a reference here such that we are able to + * modify the item. + */ + ItemSequenceCacheCell::Vector &m_cacheCells; + + /** + * Whether this CachingIterator is delivering items from + * m_cacheCell.cacheItems or from m_cacheCell.sourceIterator. + */ + bool m_usingCache; + }; +} + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |