source: trunk/src/xmlpatterns/acceltree/qacceltree_p.h@ 1023

Last change on this file since 1023 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
File size: 14.7 KB
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1/****************************************************************************
2**
3** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4** All rights reserved.
5** Contact: Nokia Corporation ([email protected])
6**
7** This file is part of the QtXmlPatterns module of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:LGPL$
10** Commercial Usage
11** Licensees holding valid Qt Commercial licenses may use this file in
12** accordance with the Qt Commercial License Agreement provided with the
13** Software or, alternatively, in accordance with the terms contained in
14** a written agreement between you and Nokia.
15**
16** GNU Lesser General Public License Usage
17** Alternatively, this file may be used under the terms of the GNU Lesser
18** General Public License version 2.1 as published by the Free Software
19** Foundation and appearing in the file LICENSE.LGPL included in the
20** packaging of this file. Please review the following information to
21** ensure the GNU Lesser General Public License version 2.1 requirements
22** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
23**
24** In addition, as a special exception, Nokia gives you certain additional
25** rights. These rights are described in the Nokia Qt LGPL Exception
26** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
27**
28** GNU General Public License Usage
29** Alternatively, this file may be used under the terms of the GNU
30** General Public License version 3.0 as published by the Free Software
31** Foundation and appearing in the file LICENSE.GPL included in the
32** packaging of this file. Please review the following information to
33** ensure the GNU General Public License version 3.0 requirements will be
34** met: http://www.gnu.org/copyleft/gpl.html.
35**
36** If you have questions regarding the use of this file, please contact
37** Nokia at [email protected].
38** $QT_END_LICENSE$
39**
40****************************************************************************/
41
42//
43// W A R N I N G
44// -------------
45//
46// This file is not part of the Qt API. It exists purely as an
47// implementation detail. This header file may change from version to
48// version without notice, or even be removed.
49//
50// We mean it.
51
52#ifndef Patternist_AccelTree_H
53#define Patternist_AccelTree_H
54
55#include <QHash>
56#include <QUrl>
57#include <QVector>
58#include <QXmlName>
59
60#include "qitem_p.h"
61#include "qnamepool_p.h"
62
63QT_BEGIN_HEADER
64
65QT_BEGIN_NAMESPACE
66
67namespace QPatternist
68{
69 template<bool> class AccelTreeBuilder;
70
71 /**
72 * @short Stores an XML document using the XPath Accelerator scheme, also
73 * known as pre/post numbering.
74 *
75 * Working on this code will be destructive without a proper understanding of
76 * the Accelerator scheme, so do check out the links. We don't implement any form
77 * of staircase join, although that is only due to time constraints.
78 *
79 * @author Frans Englich <[email protected]>
80 * @see <a href="http://www.pathfinder-xquery.org/?q=research/xpath-accel">XPath
81 * Accelerator</a>
82 * @see <a href="http://www.pathfinder-xquery.org/files/xpath-accel.pdf">Accelerating
83 * XPath Location Steps, Torsten Grust</a>
84 * @see <a href="http://citeseer.ist.psu.edu/cache/papers/cs/29367/http:zSzzSzwww.informatik.uni-konstanz.dezSz~grustzSzfileszSzstaircase-join.pdf/grust03staircase.pdf">Staircase Join:
85 * Teach a Relational DBMS to Watch its (Axis) Steps</a>
86 * @see <a href="http://ftp.cwi.nl/CWIreports/INS/INS-E0510.pdf">Loop-lifted
87 * staircase join: from XPath to XQuery, Torsten Grust</a>
88 * @see <a href="http://englich.wordpress.com/2007/01/09/xmlstat/">xmlstat, Frans Englich</a>
89 * @see <a href"http://www.inf.uni-konstanz.de/dbis/publications/download/accelerating-locsteps.pdf">Accelerating
90 * XPath Evaluation in Any RDBMS, Torsten Grust</a>
91 */
92 class Q_AUTOTEST_EXPORT AccelTree : public QAbstractXmlNodeModel
93 {
94 friend class AccelTreePrivate;
95 public:
96 using QAbstractXmlNodeModel::createIndex;
97
98 typedef QExplicitlySharedDataPointer<AccelTree> Ptr;
99 typedef qint32 PreNumber;
100 typedef PreNumber PostNumber;
101 typedef qint8 Depth;
102
103 AccelTree(const QUrl &docURI, const QUrl &bURI);
104
105 /**
106 * @short Houses data for a node, and that all node kinds have.
107 *
108 * BasicNodeData is internal to the Accel tree implementation, and is
109 * only used by those classes.
110 *
111 * @author Frans Englich <[email protected]>
112 * @todo Can't m_kind be coded somewhere else? If m_name is invalid,
113 * its bits can be used to distinguish the node types that doesn't have
114 * names, and for elements, attributes and processing instructions, we need
115 * two bits, somewhere. Attributes and processing instructions can't have a
116 * size, is that of help? There's also certain rules for the names. For instance,
117 * a processing instruction will never have a prefix nor namespace. Neither
118 * will an attribute node have a default, non-empty namespace, right?
119 * @todo Compress text nodes, add general support for it in Patternist.
120 */
121 class BasicNodeData
122 {
123 public:
124 /* No need to initialize the members. See AccelTreeBuilder. */
125 inline BasicNodeData()
126 {
127 }
128
129 inline BasicNodeData(const PreNumber aDepth,
130 const PreNumber aParent,
131 const QXmlNodeModelIndex::NodeKind k,
132 const PreNumber s,
133 const QXmlName n = QXmlName()) : m_parent(aParent)
134 , m_size(s)
135 , m_name(n)
136 , m_depth(aDepth)
137 , m_kind(k)
138 {
139 }
140
141 inline Depth depth() const
142 {
143 return m_depth;
144 }
145
146 inline PreNumber parent() const
147 {
148 return m_parent;
149 }
150
151 /**
152 * @see AccelTree::size()
153 */
154 inline PreNumber size() const
155 {
156 /* Remember that we use the m_size to signal compression if
157 * we're a text node. */
158 if(m_kind == QXmlNodeModelIndex::Text)
159 return 0;
160 else
161 return m_size;
162 }
163
164 inline void setSize(const PreNumber aSize)
165 {
166 m_size = aSize;
167 }
168
169 inline QXmlNodeModelIndex::NodeKind kind() const
170 {
171 return m_kind;
172 }
173
174 inline QXmlName name() const
175 {
176 return m_name;
177 }
178
179 inline bool isCompressed() const
180 {
181 Q_ASSERT_X(m_kind == QXmlNodeModelIndex::Text, Q_FUNC_INFO,
182 "Currently, only text nodes are compressed.");
183 /* Note, we don't call size() here, since it has logic for text
184 * nodes. */
185 return m_size == IsCompressed;
186 }
187
188 private:
189 /**
190 * This is the pre number of the parent.
191 */
192 PreNumber m_parent;
193
194 /**
195 * This is the count of children this node has.
196 *
197 * In the case of a text node, which cannot have children,
198 * it is set to IsCompressed, if the content has been the result
199 * of CompressedWhitespace::compress(). If it's not compressed,
200 * it is zero.
201 */
202 PreNumber m_size;
203
204 /**
205 * For text nodes, and less importantly, comments,
206 * this variable is not used.
207 */
208 QXmlName m_name;
209
210 Depth m_depth;
211
212 /**
213 * Technically it is sufficient with 7 bits. However, at least MSVC
214 * 2005 miscompiles it such that QXmlNodeModelIndex::Text becomes
215 * -64 instead of 64 with hilarious crashes as result.
216 *
217 * Fortunately this extra bit would be padded anyway.
218 */
219 QXmlNodeModelIndex::NodeKind m_kind : 8;
220 };
221
222 virtual QUrl baseUri(const QXmlNodeModelIndex &ni) const;
223 virtual QUrl documentUri(const QXmlNodeModelIndex &ni) const;
224 virtual QXmlNodeModelIndex::NodeKind kind(const QXmlNodeModelIndex &ni) const;
225 virtual QXmlNodeModelIndex::DocumentOrder compareOrder(const QXmlNodeModelIndex &ni1,
226 const QXmlNodeModelIndex &ni2) const;
227
228 /**
229 * @short Returns the root node.
230 *
231 * This function does not use @p n, so a default constructed
232 * QXmlNodeModelIndex may be passed.
233 */
234 virtual QXmlNodeModelIndex root(const QXmlNodeModelIndex &n) const;
235
236 virtual QXmlNodeModelIndex parent(const QXmlNodeModelIndex &ni) const;
237 virtual QXmlNodeModelIndex::Iterator::Ptr iterate(const QXmlNodeModelIndex &ni,
238 QXmlNodeModelIndex::Axis axis) const;
239 virtual QXmlName name(const QXmlNodeModelIndex &ni) const;
240 virtual QVector<QXmlName> namespaceBindings(const QXmlNodeModelIndex &n) const;
241 virtual void sendNamespaces(const QXmlNodeModelIndex &n,
242 QAbstractXmlReceiver *const receiver) const;
243 virtual QString stringValue(const QXmlNodeModelIndex &n) const;
244 virtual QVariant typedValue(const QXmlNodeModelIndex &n) const;
245 virtual Item::Iterator::Ptr sequencedTypedValue(const QXmlNodeModelIndex &n) const;
246 virtual ItemType::Ptr type(const QXmlNodeModelIndex &ni) const;
247 virtual QXmlNodeModelIndex elementById(const QXmlName &id) const;
248 virtual QVector<QXmlNodeModelIndex> nodesByIdref(const QXmlName &idref) const;
249 virtual void copyNodeTo(const QXmlNodeModelIndex &node,
250 QAbstractXmlReceiver *const receiver,
251 const NodeCopySettings &settings) const;
252
253 friend class AccelTreeBuilder<false>;
254 friend class AccelTreeBuilder<true>;
255
256 enum Constants
257 {
258 IsCompressed = 1
259 };
260
261 /**
262 * The key is the pre number of an element, and the value is a vector
263 * containing the namespace declarations being declared on that
264 * element. Therefore, it does not reflect the namespaces being in
265 * scope for that element. For that, a walk along axis ancestor is
266 * necessary.
267 */
268 QHash<PreNumber, QVector<QXmlName> > namespaces;
269
270 /**
271 * Stores data for nodes. The QHash's value is the data of the processing instruction, and the
272 * content of a text node or comment.
273 */
274 QHash<PreNumber, QString> data;
275
276 QVector<BasicNodeData> basicData;
277 QHash<PreNumber, QPair<qint64, qint64> > sourcePositions;
278
279 inline QUrl documentUri() const
280 {
281 return m_documentURI;
282 }
283
284 inline QUrl baseUri() const
285 {
286 return m_baseURI;
287 }
288
289 /**
290 * @short Returns @c true if the node identified by @p pre has child
291 * nodes(in the sense of the XDM), but also if it has namespace nodes,
292 * or attribute nodes.
293 */
294 inline bool hasChildren(const PreNumber pre) const
295 {
296 return basicData.at(pre).size() > 0;
297 }
298
299 /**
300 * @short Returns the parent node of @p pre.
301 *
302 * If @p pre parent doesn't have a parent node, the return value is
303 * undefined.
304 *
305 * @see hasParent()
306 */
307 inline PreNumber parent(const PreNumber pre) const
308 {
309 return basicData.at(pre).parent();
310 }
311
312 inline bool hasParent(const PreNumber pre) const
313 {
314 return basicData.at(pre).depth() > 0;
315 }
316
317 inline bool hasFollowingSibling(const PreNumber pre) const
318 {
319 return pre < maximumPreNumber();
320 }
321
322 inline PostNumber postNumber(const PreNumber pre) const
323 {
324 const BasicNodeData &b = basicData.at(pre);
325 return pre + b.size() - b.depth();
326 }
327
328 inline QXmlNodeModelIndex::NodeKind kind(const PreNumber pre) const
329 {
330 return basicData.at(pre).kind();
331 }
332
333 inline PreNumber maximumPreNumber() const
334 {
335 return basicData.count() - 1;
336 }
337
338 inline PreNumber toPreNumber(const QXmlNodeModelIndex n) const
339 {
340 return n.data();
341 }
342
343 inline PreNumber size(const PreNumber pre) const
344 {
345 Q_ASSERT_X(basicData.at(pre).size() != -1, Q_FUNC_INFO,
346 "The size cannot be -1. That means an uninitialized value is attempted to be used.");
347 return basicData.at(pre).size();
348 }
349
350 inline Depth depth(const PreNumber pre) const
351 {
352 return basicData.at(pre).depth();
353 }
354
355 void printStats(const NamePool::Ptr &np) const;
356
357 inline QXmlName name(const PreNumber pre) const
358 {
359 return basicData.at(pre).name();
360 }
361
362 inline bool isCompressed(const PreNumber pre) const
363 {
364 return basicData.at(pre).isCompressed();
365 }
366
367 static inline bool hasPrefix(const QVector<QXmlName> &nbs, const QXmlName::PrefixCode prefix);
368
369 QUrl m_documentURI;
370 QUrl m_baseURI;
371
372 protected:
373 virtual QXmlNodeModelIndex nextFromSimpleAxis(QAbstractXmlNodeModel::SimpleAxis,
374 const QXmlNodeModelIndex&) const;
375 virtual QVector<QXmlNodeModelIndex> attributes(const QXmlNodeModelIndex &element) const;
376
377 private:
378 /**
379 * Returns the source location for the object with the given @p index.
380 */
381 QSourceLocation sourceLocation(const QXmlNodeModelIndex &index) const;
382
383 /**
384 * Copies the children of @p node to @p receiver.
385 */
386 inline void copyChildren(const QXmlNodeModelIndex &node,
387 QAbstractXmlReceiver *const receiver,
388 const NodeCopySettings &settings) const;
389
390 /**
391 * The key is the xml:id value, and the value is the element
392 * with that value.
393 */
394 QHash<QXmlName::LocalNameCode, PreNumber> m_IDs;
395 };
396}
397
398Q_DECLARE_TYPEINFO(QPatternist::AccelTree::BasicNodeData, Q_MOVABLE_TYPE);
399
400QT_END_NAMESPACE
401
402QT_END_HEADER
403
404#endif
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