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+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+
+#include "qcachingiterator_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+CachingIterator::CachingIterator(ItemSequenceCacheCell::Vector &cacheCells,
+ const VariableSlotID slot,
+ const DynamicContext::Ptr &context) : m_position(0),
+ m_varSlot(slot),
+ m_context(context),
+ m_cacheCells(cacheCells),
+ m_usingCache(true)
+{
+ Q_ASSERT(m_varSlot > -1);
+ Q_ASSERT(m_context);
+ Q_ASSERT(m_cacheCells.at(m_varSlot).sourceIterator);
+ Q_ASSERT_X((m_cacheCells.at(m_varSlot).cachedItems.isEmpty() && m_cacheCells.at(m_varSlot).cacheState == ItemSequenceCacheCell::Empty) ||
+ m_cacheCells.at(m_varSlot).cacheState == ItemSequenceCacheCell::PartiallyPopulated,
+ Q_FUNC_INFO,
+ "It makes no sense to construct a CachingIterator for a cache that is ItemSequenceCacheCell::Full.");
+}
+
+Item CachingIterator::next()
+{
+ ItemSequenceCacheCell &cell = m_cacheCells[m_varSlot];
+ if(m_position == -1)
+ return Item();
+
+ if(m_usingCache)
+ {
+ ++m_position;
+
+ /* QAbstractXmlForwardIterator::position() starts at 1, while Qt's container classes
+ * starts at 0. */
+ if(m_position - 1 < cell.cachedItems.count())
+ {
+ m_current = cell.cachedItems.at(m_position - 1);
+ return m_current;
+ }
+ else
+ {
+ cell.cacheState = ItemSequenceCacheCell::PartiallyPopulated;
+ m_usingCache = false;
+ /* We decrement here so we don't have to add a branch for this
+ * when using the source QAbstractXmlForwardIterator below. */
+ --m_position;
+ }
+ }
+
+ m_current = cell.sourceIterator->next();
+
+ if(m_current)
+ {
+ cell.cachedItems.append(m_current);
+ Q_ASSERT(cell.cacheState == ItemSequenceCacheCell::PartiallyPopulated);
+ ++m_position;
+ return m_current;
+ }
+ else
+ {
+ m_position = -1;
+ cell.cacheState = ItemSequenceCacheCell::Full;
+ return Item();
+ }
+}
+
+Item CachingIterator::current() const
+{
+ return m_current;
+}
+
+xsInteger CachingIterator::position() const
+{
+ return m_position;
+}
+
+Item::Iterator::Ptr CachingIterator::copy() const
+{
+ const ItemSequenceCacheCell &cell = m_cacheCells.at(m_varSlot);
+ if(cell.cacheState == ItemSequenceCacheCell::Full)
+ return makeListIterator(cell.cachedItems);
+ else
+ return Item::Iterator::Ptr(new CachingIterator(m_cacheCells, m_varSlot, m_context));
+}
+
+QT_END_NAMESPACE