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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@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 <frans.englich@nokia.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 <frans.englich@nokia.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