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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_CacheCells_H
53 #define Patternist_CacheCells_H
58 #include <private/qitem_p.h>
68 * @short Represents a cache entry for a single Item,
69 * as opposed to for a sequence of items.
71 * A characteristic of the ItemCacheCell is that it has two states:
72 * either its full or it's not, since it only deals with a single
75 * Remember that cachedItem doesn't tell the state of the ItemCacheCell.
76 * For instance, it can have a null pointer, the empty sequence, and that
77 * can be the value of its cache.
79 * @author Frans Englich <frans.englich@nokia.com>
84 typedef QList<ItemCacheCell> List;
85 typedef QVector<ItemCacheCell> Vector;
92 inline ItemCacheCell() : cacheState(Empty)
97 CacheState cacheState;
101 * @short Represents a cache entry for a sequence of items.
103 * As opposed to ItemCacheCell, ItemSequenceCacheCell can be partially
104 * populated: e.g, four items is in the cache while three remains in the
105 * source. For that reason ItemSequenceCacheCell in addition to the source
106 * also carried an QAbstractXmlForwardIterator which is the source, such
107 * that it can continue to populate the cache when it runs out.
109 * @author Frans Englich <frans.englich@nokia.com>
111 class ItemSequenceCacheCell
114 typedef QList<ItemSequenceCacheCell> List;
115 typedef QVector<ItemSequenceCacheCell> Vector;
124 inline ItemSequenceCacheCell() : cacheState(Empty)
129 Item::List cachedItems;
130 Item::Iterator::Ptr sourceIterator;
131 CacheState cacheState;
133 * In XSL-T, we can have circularity which we cannot detect statically.
134 * For instance, a global variable invokes a template, and the template
135 * uses the variable. We can't detect that, because we can't figure out
136 * what template will be invoked.
138 * For solution we have this toggle, which is set temporarily on the
139 * cell such that EvaluationCache can detect whether it's trashing
142 * One might think that it would be sufficient to flag usage of the
143 * variable in an arbitrary template, but that would also flag valid
150 Q_DECLARE_TYPEINFO(QPatternist::ItemCacheCell, Q_MOVABLE_TYPE);
151 Q_DECLARE_TYPEINFO(QPatternist::ItemSequenceCacheCell, Q_MOVABLE_TYPE);