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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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.
**
** 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.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QString>
#include "qcompressedwhitespace_p.h"
QT_BEGIN_NAMESPACE
using namespace QPatternist;
CompressedWhitespace::CharIdentifier CompressedWhitespace::toIdentifier(const QChar ch)
{
switch(ch.unicode())
{
case ' ':
return Space;
case '\n':
return LF;
case '\r':
return CR;
case '\t':
return Tab;
default:
{
Q_ASSERT_X(false, Q_FUNC_INFO,
"The caller must guarantee only whitespace is passed.");
return Tab;
}
}
}
bool CompressedWhitespace::isEven(const int number)
{
Q_ASSERT(number >= 0);
return number % 2 == 0;
}
quint8 CompressedWhitespace::toCompressedChar(const QChar ch, const int len)
{
Q_ASSERT(len > 0);
Q_ASSERT(len <= MaxCharCount);
return len + toIdentifier(ch);
}
QChar CompressedWhitespace::toChar(const CharIdentifier id)
{
switch(id)
{
case Space: return QLatin1Char(' ');
case CR: return QLatin1Char('\r');
case LF: return QLatin1Char('\n');
case Tab: return QLatin1Char('\t');
default:
{
Q_ASSERT_X(false, Q_FUNC_INFO, "Unexpected input");
return QChar();
}
}
}
QString CompressedWhitespace::compress(const QStringRef &input)
{
Q_ASSERT(!isEven(1) && isEven(0) && isEven(2));
Q_ASSERT(!input.isEmpty());
QString result;
const int len = input.length();
/* The amount of compressed characters. For instance, if input is
* four spaces followed by one tab, compressedChars will be 2, and the resulting
* QString will have a length of 1, two compressedChars stored in one QChar. */
int compressedChars = 0;
for(int i = 0; i < len; ++i)
{
const QChar c(input.at(i));
int start = i;
while(true)
{
if(i + 1 == input.length() || input.at(i + 1) != c)
break;
else
++i;
}
/* The length of subsequent whitespace characters in the input. */
int wsLen = (i - start) + 1;
/* We might get a sequence of whitespace that is so long, that we can't
* store it in one unit/byte. In that case we chop it into as many subsequent
* ones that is needed. */
while(true)
{
const int unitLength = qMin(wsLen, int(MaxCharCount));
wsLen -= unitLength;
ushort resultCP = toCompressedChar(c, unitLength);
if(isEven(compressedChars))
result += QChar(resultCP);
else
{
resultCP = resultCP << 8;
resultCP |= result.at(result.size() - 1).unicode();
result[result.size() - 1] = resultCP;
}
++compressedChars;
if(wsLen == 0)
break;
}
}
return result;
}
QString CompressedWhitespace::decompress(const QString &input)
{
Q_ASSERT(!input.isEmpty());
const int len = input.length() * 2;
QString retval;
for(int i = 0; i < len; ++i)
{
ushort cp = input.at(i / 2).unicode();
if(isEven(i))
cp &= Lower8Bits;
else
{
cp = cp >> 8;
if(cp == 0)
return retval;
}
const quint8 wsLen = cp & Lower6Bits;
const quint8 id = cp & UpperTwoBits;
/* Resize retval, and fill in on the top. */
const int oldSize = retval.size();
const int newSize = retval.size() + wsLen;
retval.resize(newSize);
const QChar ch(toChar(CharIdentifier(id)));
for(int f = oldSize; f < newSize; ++f)
retval[f] = ch;
}
return retval;
}
QT_END_NAMESPACE
|
