mirror of
https://bitbucket.org/smil3y/kdelibs.git
synced 2025-02-24 19:02:48 +00:00
100 lines
2.8 KiB
C++
100 lines
2.8 KiB
C++
/*
|
|
This file is part of the KDE libraries
|
|
Copyright (C) 2008 Christian Ehrlicher <ch.ehrlicher@gmx.de>
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
This library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public License
|
|
along with this library; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#ifndef KMEMFILE_H
|
|
#define KMEMFILE_H
|
|
|
|
#ifndef QT_NO_SHAREDMEMORY
|
|
|
|
#include <QtCore/QIODevice>
|
|
#include <kdecore_export.h>
|
|
|
|
/**
|
|
* @internal
|
|
* Simple QIODevice for QSharedMemory to keep ksycoca cache in memory only once
|
|
* The first call to open() loads the file into a shm segment. Every
|
|
* subsequent call only attaches to this segment. When the file content changed,
|
|
* you have to execute KMemFile::fileContentsChanged() to update the internal
|
|
* structures. The next call to open() creates a new shm segment. The old one
|
|
* is automatically destroyed when the last process closed KMemFile.
|
|
*/
|
|
|
|
class KDECORE_EXPORT KMemFile : public QIODevice
|
|
{
|
|
public:
|
|
/**
|
|
* ctor
|
|
*
|
|
* @param filename the file to load into memory
|
|
* @param parent our parent
|
|
*/
|
|
explicit KMemFile ( const QString &filename, QObject *parent = 0 );
|
|
/**
|
|
* dtor
|
|
*/
|
|
virtual ~KMemFile();
|
|
/**
|
|
* closes the KMemFile
|
|
*
|
|
* @reimp
|
|
*/
|
|
virtual void close ();
|
|
/**
|
|
* As KMemFile is a random access device, it returns false
|
|
*
|
|
* @reimp
|
|
*/
|
|
virtual bool isSequential () const;
|
|
/**
|
|
* @reimp
|
|
* @param mode only QIODevice::ReadOnly is accepted
|
|
*/
|
|
virtual bool open ( OpenMode mode );
|
|
/**
|
|
* Sets the current read/write position to pos
|
|
* @reimp
|
|
* @param pos the new read/write position
|
|
*/
|
|
virtual bool seek ( qint64 pos );
|
|
/**
|
|
* Returns the size of the file
|
|
* @reimp
|
|
*/
|
|
virtual qint64 size () const;
|
|
/**
|
|
* This static function updates the internal information about the file
|
|
* loaded into shared memory. The next time the file is opened, the file is
|
|
* reread from the file system.
|
|
*/
|
|
static void fileContentsChanged ( const QString &filename );
|
|
protected:
|
|
/** @reimp */
|
|
virtual qint64 readData ( char * data, qint64 maxSize );
|
|
/** @reimp */
|
|
virtual qint64 writeData ( const char * data, qint64 maxSize );
|
|
private:
|
|
class Private;
|
|
friend class Private;
|
|
Private * const d;
|
|
};
|
|
|
|
#endif //QT_NO_SHAREDMEMORY
|
|
|
|
#endif // KMEMFILE_H
|