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46 // This file is not part of the Qt API. It exists purely as an
47 // implementation detail. This header file may change from version to
48 // version without notice, or even be removed.
52 #ifndef Patternist_CachingIterator_H
53 #define Patternist_CachingIterator_H
58 #include <private/qdynamiccontext_p.h>
59 #include <private/qitem_p.h>
68 * @short An QAbstractXmlForwardIterator that gets its item from a cache unless its empty, in
69 * which case it continues to populate the cache as well as deliver on its
70 * own from a source QAbstractXmlForwardIterator.
72 * @author Frans Englich <frans.frans.englich@nokia.com>
73 * @ingroup Patternist_iterators
75 class CachingIterator : public Item::Iterator
79 * We always use the same cache cell so why don't we use it directly,
80 * instead of passing the slot and ItemSequenceCacheCell::Vector to
81 * this class? Because the GenericDynamicContext might decide to resize
82 * the vector and that would invalidate the reference.
84 * We intentionally pass in a non-const reference here.
86 CachingIterator(ItemSequenceCacheCell::Vector &cacheCells,
87 const VariableSlotID slot,
88 const DynamicContext::Ptr &context);
91 virtual Item current() const;
92 virtual xsInteger position() const;
93 virtual Item::Iterator::Ptr copy() const;
100 * This variable cannot be called m_slot, because
101 * /usr/include/sys/sysmacros.h on hpuxi-acc defines it.
103 const VariableSlotID m_varSlot;
106 * We don't use the context. We only keep a reference such that it
107 * doesn't get deleted, and m_cacheCells starts to dangle.
109 const DynamicContext::Ptr m_context;
112 * We intentionally store a reference here such that we are able to
115 ItemSequenceCacheCell::Vector &m_cacheCells;
118 * Whether this CachingIterator is delivering items from
119 * m_cacheCell.cacheItems or from m_cacheCell.sourceIterator.