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Diffstat (limited to 'src/sql/drivers/cache/qsqlcachedresult.cpp')
| -rw-r--r-- | src/sql/drivers/cache/qsqlcachedresult.cpp | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/src/sql/drivers/cache/qsqlcachedresult.cpp b/src/sql/drivers/cache/qsqlcachedresult.cpp new file mode 100644 index 0000000..4891b97 --- /dev/null +++ b/src/sql/drivers/cache/qsqlcachedresult.cpp @@ -0,0 +1,259 @@ +/**************************************************************************** +** +** Implementation of cached Qt SQL result classes +** +** +** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved. +** +** This file is part of the sql module of the Qt GUI Toolkit. +** +** This file may be used under the terms of the GNU General +** Public License versions 2.0 or 3.0 as published by the Free +** Software Foundation and appearing in the files LICENSE.GPL2 +** and LICENSE.GPL3 included in the packaging of this file. +** Alternatively you may (at your option) use any later version +** of the GNU General Public License if such license has been +** publicly approved by Trolltech ASA (or its successors, if any) +** and the KDE Free Qt Foundation. +** +** Please review the following information to ensure GNU General +** Public Licensing requirements will be met: +** http://trolltech.com/products/qt/licenses/licensing/opensource/. +** If you are unsure which license is appropriate for your use, please +** review the following information: +** http://trolltech.com/products/qt/licenses/licensing/licensingoverview +** or contact the sales department at sales@trolltech.com. +** +** This file may be used under the terms of the Q Public License as +** defined by Trolltech ASA and appearing in the file LICENSE.QPL +** included in the packaging of this file. Licensees holding valid Qt +** Commercial licenses may use this file in accordance with the Qt +** Commercial License Agreement provided with the Software. +** +** This file is provided "AS IS" with NO WARRANTY OF ANY KIND, +** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted +** herein. +** +**********************************************************************/ + +#include "qsqlcachedresult.h" +#include <qdatetime.h> + +#ifndef QT_NO_SQL +static const uint initial_cache_size = 128; + +class QtSqlCachedResultPrivate +{ +public: + QtSqlCachedResultPrivate(); + bool seek(int i); + void init(int count, bool fo); + void cleanup(); + QtSqlCachedResult::RowCache* next(); + void revertLast(); + + QtSqlCachedResult::RowsetCache *cache; + QtSqlCachedResult::RowCache *current; + int rowCacheEnd; + int colCount; + bool forwardOnly; +}; + +QtSqlCachedResultPrivate::QtSqlCachedResultPrivate(): + cache(0), current(0), rowCacheEnd(0), colCount(0), forwardOnly(FALSE) +{ +} + +void QtSqlCachedResultPrivate::cleanup() +{ + if (cache) { + for (int i = 0; i < rowCacheEnd; ++i) + delete (*cache)[i]; + delete cache; + cache = 0; + } + if (forwardOnly) + delete current; + current = 0; + forwardOnly = FALSE; + colCount = 0; + rowCacheEnd = 0; +} + +void QtSqlCachedResultPrivate::init(int count, bool fo) +{ + cleanup(); + forwardOnly = fo; + colCount = count; + if (fo) + current = new QtSqlCachedResult::RowCache(count); + else + cache = new QtSqlCachedResult::RowsetCache(initial_cache_size); +} + +QtSqlCachedResult::RowCache *QtSqlCachedResultPrivate::next() +{ + if (forwardOnly) + return current; + + Q_ASSERT(cache); + current = new QtSqlCachedResult::RowCache(colCount); + if (rowCacheEnd == (int)cache->size()) + cache->resize(cache->size() * 2); + cache->insert(rowCacheEnd++, current); + return current; +} + +bool QtSqlCachedResultPrivate::seek(int i) +{ + if (forwardOnly || i < 0) + return FALSE; + if (i >= rowCacheEnd) + return FALSE; + current = (*cache)[i]; + return TRUE; +} + +void QtSqlCachedResultPrivate::revertLast() +{ + if (forwardOnly) + return; + --rowCacheEnd; + delete current; + current = 0; +} + +////////////// + +QtSqlCachedResult::QtSqlCachedResult(const QSqlDriver * db ): QSqlResult ( db ) +{ + d = new QtSqlCachedResultPrivate(); +} + +QtSqlCachedResult::~QtSqlCachedResult() +{ + delete d; +} + +void QtSqlCachedResult::init(int colCount) +{ + d->init(colCount, isForwardOnly()); +} + +bool QtSqlCachedResult::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(0)) + return FALSE; + setAt(at() + 1); + } + if (!gotoNext(d->current)) + return FALSE; + setAt(at() + 1); + return TRUE; + } + if (d->seek(i)) { + setAt(i); + return TRUE; + } + setAt(d->rowCacheEnd - 1); + while (at() < i) { + if (!cacheNext()) + return FALSE; + } + return TRUE; +} + +bool QtSqlCachedResult::fetchNext() +{ + if (d->seek(at() + 1)) { + setAt(at() + 1); + return TRUE; + } + return cacheNext(); +} + +bool QtSqlCachedResult::fetchPrev() +{ + return fetch(at() - 1); +} + +bool QtSqlCachedResult::fetchFirst() +{ + if (d->forwardOnly && at() != QSql::BeforeFirst) { + return FALSE; + } + if (d->seek(0)) { + setAt(0); + return TRUE; + } + return cacheNext(); +} + +bool QtSqlCachedResult::fetchLast() +{ + if (at() == QSql::AfterLast) { + if (d->forwardOnly) + return FALSE; + else + return fetch(d->rowCacheEnd - 1); + } + + int i = at(); + while (fetchNext()) + i++; /* brute force */ + if (d->forwardOnly && at() == QSql::AfterLast) { + setAt(i); + return TRUE; + } else { + return fetch(d->rowCacheEnd - 1); + } +} + +QVariant QtSqlCachedResult::data(int i) +{ + if (!d->current || i >= (int)d->current->size() || i < 0) + return QVariant(); + + return (*d->current)[i]; +} + +bool QtSqlCachedResult::isNull(int i) +{ + if (!d->current || i >= (int)d->current->size() || i < 0) + return TRUE; + + return (*d->current)[i].isNull(); +} + +void QtSqlCachedResult::cleanup() +{ + setAt(QSql::BeforeFirst); + setActive(FALSE); + d->cleanup(); +} + +bool QtSqlCachedResult::cacheNext() +{ + if (!gotoNext(d->next())) { + d->revertLast(); + return FALSE; + } + setAt(at() + 1); + return TRUE; +} + +int QtSqlCachedResult::colCount() const +{ + return d->colCount; +} +#endif // QT_NO_SQL |