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Diffstat (limited to 'src/xmlpatterns/expr/qcachecells_p.h')
| -rw-r--r-- | src/xmlpatterns/expr/qcachecells_p.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qcachecells_p.h b/src/xmlpatterns/expr/qcachecells_p.h new file mode 100644 index 0000000..c9f78a6 --- /dev/null +++ b/src/xmlpatterns/expr/qcachecells_p.h @@ -0,0 +1,157 @@ +/**************************************************************************** +** +** 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_CacheCells_H +#define Patternist_CacheCells_H + +#include <QList> +#include <QVector> + +#include "qitem_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +namespace QPatternist +{ + + /** + * @short Represents a cache entry for a single Item, + * as opposed to for a sequence of items. + * + * A characteristic of the ItemCacheCell is that it has two states: + * either its full or it's not, since it only deals with a single + * item. + * + * Remember that cachedItem doesn't tell the state of the ItemCacheCell. + * For instance, it can have a null pointer, the empty sequence, and that + * can be the value of its cache. + * + * @author Frans Englich <fenglich@trolltech.com> + */ + class ItemCacheCell + { + public: + typedef QList<ItemCacheCell> List; + typedef QVector<ItemCacheCell> Vector; + enum CacheState + { + Full, + Empty + }; + + inline ItemCacheCell() : cacheState(Empty) + { + } + + Item cachedItem; + CacheState cacheState; + }; + + /** + * @short 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 <fenglich@trolltech.com> + */ + class ItemSequenceCacheCell + { + public: + typedef QList<ItemSequenceCacheCell> List; + typedef QVector<ItemSequenceCacheCell> Vector; + + enum CacheState + { + Full, + Empty, + PartiallyPopulated + }; + + inline ItemSequenceCacheCell() : cacheState(Empty) + , inUse(false) + { + } + + Item::List cachedItems; + Item::Iterator::Ptr sourceIterator; + CacheState cacheState; + /** + * 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. + */ + bool inUse; + }; +} + +Q_DECLARE_TYPEINFO(QPatternist::ItemCacheCell, Q_MOVABLE_TYPE); +Q_DECLARE_TYPEINFO(QPatternist::ItemSequenceCacheCell, Q_MOVABLE_TYPE); + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |