summaryrefslogtreecommitdiffstats
path: root/src/svnqt/cache/sqlite3/qsqlcachedresult.cpp
blob: 8a23183da2e82ea50a90ede1cecb9577a649d5d3 (plain)
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/****************************************************************************
**
** Copyright (C) 1992-2005 Trolltech AS. All rights reserved.
**
** This file is part of the sql module of the Qt Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** See http://www.trolltech.com/pricing.html or email [email protected] for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact [email protected] if any conditions of this licensing are
** not clear to you.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qsqlcachedresult.h"

#include <qvariant.h>
#include <qdatetime.h>
#include <qvaluevector.h>

static const uint initial_cache_size = 128;

class QSqlCachedResultPrivate
{
public:
    QSqlCachedResultPrivate();
    bool canSeek(int i) const;
    inline int cacheCount() const;
    void init(int count, bool fo);
    void cleanup();
    int nextIndex();
    void revertLast();

    QSqlCachedResult::ValueCache cache;
    int rowCacheEnd;
    int colCount;
    bool forwardOnly;
};

QSqlCachedResultPrivate::QSqlCachedResultPrivate():
    rowCacheEnd(0), colCount(0), forwardOnly(false)
{
}

void QSqlCachedResultPrivate::cleanup()
{
    cache.clear();
    forwardOnly = false;
    colCount = 0;
    rowCacheEnd = 0;
}

void QSqlCachedResultPrivate::init(int count, bool fo)
{
    Q_ASSERT(count);
    cleanup();
    forwardOnly = fo;
    colCount = count;
    if (fo) {
        cache.resize(count);
        rowCacheEnd = count;
    } else {
        cache.resize(initial_cache_size * count);
    }
}

int QSqlCachedResultPrivate::nextIndex()
{
    if (forwardOnly)
        return 0;
    int newIdx = rowCacheEnd;
    if (rowCacheEnd == (int)cache.size())
        cache.resize(cache.size() * 2);
/*    if (newIdx + colCount > cache.size()){
        if(cache.size() * 2 < cache.size() + 10000)
            cache.resize(cache.size() * 2);
        else
            cache.resize(cache.size() + 10000);
    }*/
    rowCacheEnd += colCount;

    return newIdx;
}

bool QSqlCachedResultPrivate::canSeek(int i) const
{
    if (forwardOnly || i < 0)
        return false;
    return rowCacheEnd >= (i + 1) * colCount;
}

void QSqlCachedResultPrivate::revertLast()
{
    if (forwardOnly)
        return;
    rowCacheEnd -= colCount;
}

inline int QSqlCachedResultPrivate::cacheCount() const
{
    Q_ASSERT(!forwardOnly);
    Q_ASSERT(colCount);
    return rowCacheEnd / colCount;
}

//////////////

QSqlCachedResult::QSqlCachedResult(const QSqlDriver * db): QSqlResult (db)
{
    d = new QSqlCachedResultPrivate();
}

QSqlCachedResult::~QSqlCachedResult()
{
    delete d;
}

void QSqlCachedResult::init(int colCount)
{
    d->init(colCount, isForwardOnly());
}

bool QSqlCachedResult::fetch(int i)
{
    if ((!isActive()) || (i < 0))
        return false;
    if (at() == i)
        return true;
    if (d->forwardOnly) {
        // speed hack - do not copy values if not needed
        if (at() > i || at() == QSql::AfterLast)
            return false;
        while(at() < i - 1) {
            if (!gotoNext(d->cache, -1))
                return false;
            setAt(at() + 1);
        }
        if (!gotoNext(d->cache, 0))
            return false;
        setAt(at() + 1);
        return true;
    }
    if (d->canSeek(i)) {
        setAt(i);
        return true;
    }
    if (d->rowCacheEnd > 0)
        setAt(d->cacheCount()-1);
    while (at() < i) {
        if (!cacheNext())
            return false;
    }
    return true;
}

bool QSqlCachedResult::fetchNext()
{
    if (d->canSeek(at() + 1)) {
        setAt(at() + 1);
        return true;
    }
    return cacheNext();
}

bool QSqlCachedResult::fetchPrevious()
{
    return fetch(at() - 1);
}

bool QSqlCachedResult::fetchFirst()
{
    if (d->forwardOnly && at() != QSql::BeforeFirst) {
        return false;
    }
    if (d->canSeek(0)) {
        setAt(0);
        return true;
    }
    return cacheNext();
}

bool QSqlCachedResult::fetchLast()
{
    if (at() == QSql::AfterLast) {
        if (d->forwardOnly)
            return false;
        else
            return fetch(d->cacheCount() - 1);
    }

    int i = at();
    while (fetchNext())
        ++i; /* brute force */
    if (d->forwardOnly && at() == QSql::AfterLast) {
        setAt(i);
        return true;
    } else {
        return fetch(i);
    }
}

QVariant QSqlCachedResult::data(int i)
{
    int idx = d->forwardOnly ? i : at() * d->colCount + i;
    if (i >= d->colCount || i < 0 || at() < 0 || idx >= d->rowCacheEnd)
        return QVariant();

    return d->cache.at(idx);
}

bool QSqlCachedResult::isNull(int i)
{
    int idx = d->forwardOnly ? i : at() * d->colCount + i;
    if (i > d->colCount || i < 0 || at() < 0 || idx >= d->rowCacheEnd)
        return true;

    return d->cache.at(idx).isNull();
}

void QSqlCachedResult::cleanup()
{
    setAt(QSql::BeforeFirst);
    setActive(false);
    d->cleanup();
}

bool QSqlCachedResult::cacheNext()
{
    if (!gotoNext(d->cache, d->nextIndex())) {
        d->revertLast();
        return false;
    }
    setAt(at() + 1);
    return true;
}

int QSqlCachedResult::colCount() const
{
    return d->colCount;
}

QSqlCachedResult::ValueCache &QSqlCachedResult::cache()
{
    return d->cache;
}