--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qcachecells_p.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,157 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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