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| ** Copyright (C) 2016 The Qt Company Ltd. |
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| |
| // |
| // 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 <private/qdynamiccontext_p.h> |
| #include <private/qitem_p.h> |
| |
| 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.frans.englich@nokia.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 |
| |
| #endif |