1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/****************************************************************************
**
** Copyright (C) 2010 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.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#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
|
