QPatternist::ItemSequenceCacheCell Class Reference

Represents a cache entry for a sequence of items. More...

#include <qcachecells_p.h>

Public Types
enum	CacheState { Full, Empty, PartiallyPopulated }
typedef QList< ItemSequenceCacheCell >	List
typedef QVector< ItemSequenceCacheCell >	Vector

Public Functions
	ItemSequenceCacheCell ()

Public Variables
Item::List	cachedItems
CacheState	cacheState
bool	inUse
Item::Iterator::Ptr	sourceIterator

Detailed Description

Represents a cache entry for a sequence of items.

As opposed to ItemCacheCell, ItemSequenceCacheCell can be partially populated: e.g, four items is in the cache while three remains in the source. For that reason ItemSequenceCacheCell in addition to the source also carried an QAbstractXmlForwardIterator which is the source, such that it can continue to populate the cache when it runs out.

Author

Frans Englich frans.nosp@m..eng.nosp@m.lich@.nosp@m.noki.nosp@m.a.com

Definition at line 111 of file qcachecells_p.h.

Typedefs

List

typedef QList<ItemSequenceCacheCell> QPatternist::ItemSequenceCacheCell::List

Definition at line 114 of file qcachecells_p.h.

Vector

typedef QVector<ItemSequenceCacheCell> QPatternist::ItemSequenceCacheCell::Vector

Definition at line 115 of file qcachecells_p.h.

Enumerations

CacheState

enum QPatternist::ItemSequenceCacheCell::CacheState

Enumerator
Full
Empty
PartiallyPopulated

Definition at line 117 of file qcachecells_p.h.

        {
            Full,
            Empty,
            PartiallyPopulated
        };

Constructors and Destructors

ItemSequenceCacheCell()

QPatternist::ItemSequenceCacheCell::ItemSequenceCacheCell ( )

inline

Definition at line 124 of file qcachecells_p.h.

                                       : cacheState(Empty)
                                       , inUse(false)
        {
        }

Properties

cachedItems

Item::List QPatternist::ItemSequenceCacheCell::cachedItems

Definition at line 129 of file qcachecells_p.h.

Referenced by QPatternist::CachingIterator::CachingIterator(), QPatternist::CachingIterator::copy(), QPatternist::EvaluationCache< IsForGlobal >::evaluateSequence(), QPatternist::EvaluationCache< IsForGlobal >::evaluateSingleton(), and QPatternist::CachingIterator::next().

cacheState

CacheState QPatternist::ItemSequenceCacheCell::cacheState

Definition at line 131 of file qcachecells_p.h.

Referenced by QPatternist::CachingIterator::CachingIterator(), QPatternist::CachingIterator::copy(), QPatternist::EvaluationCache< IsForGlobal >::evaluateSequence(), and QPatternist::CachingIterator::next().

inUse

bool QPatternist::ItemSequenceCacheCell::inUse

In XSL-T, we can have circularity which we cannot detect statically. For instance, a global variable invokes a template, and the template uses the variable. We can't detect that, because we can't figure out what template will be invoked.

For solution we have this toggle, which is set temporarily on the cell such that EvaluationCache can detect whether it's trashing itself.

One might think that it would be sufficient to flag usage of the variable in an arbitrary template, but that would also flag valid cases.

Definition at line 146 of file qcachecells_p.h.

Referenced by QPatternist::EvaluationCache< IsForGlobal >::evaluateSequence().

sourceIterator

Item::Iterator::Ptr QPatternist::ItemSequenceCacheCell::sourceIterator

Definition at line 130 of file qcachecells_p.h.

Referenced by QPatternist::CachingIterator::CachingIterator(), QPatternist::EvaluationCache< IsForGlobal >::evaluateSequence(), and QPatternist::CachingIterator::next().

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The documentation for this class was generated from the following file:

• /src/xmlpatterns/expr/qcachecells_p.h