You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
106 lines
3.7 KiB
106 lines
3.7 KiB
/* This file is part of the KDE libraries
|
|
Copyright (C) 2001, 2002 David Faure <david@mandrakesoft.com>
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public
|
|
License version 2 as published by the Free Software Foundation.
|
|
|
|
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 klimitediodevice_h
|
|
#define klimitediodevice_h
|
|
|
|
#include <kdebug.h>
|
|
#include <tqiodevice.h>
|
|
/**
|
|
* A readonly device that reads from an underlying device
|
|
* from a given point to another (e.g. to give access to a single
|
|
* file inside an archive).
|
|
* @author David Faure <david@mandrakesoft.com>
|
|
* @since 3.1
|
|
*/
|
|
class KIO_EXPORT KLimitedIODevice : public TQIODevice
|
|
{
|
|
public:
|
|
/**
|
|
* Creates a new KLimitedIODevice.
|
|
* @param dev the underlying device, opened or not
|
|
* This device itself auto-opens (in readonly mode), no need to open it.
|
|
* @param start where to start reading (position in bytes)
|
|
* @param length the length of the data to read (in bytes)
|
|
*/
|
|
KLimitedIODevice( TQIODevice *dev, int start, int length )
|
|
: m_dev( dev ), m_start( start ), m_length( length )
|
|
{
|
|
//kdDebug(7005) << "KLimitedIODevice::KLimitedIODevice start=" << start << " length=" << length << endl;
|
|
setType( IO_Direct ); // we support sequential too, but then atEnd() tries getch/ungetch !
|
|
open( IO_ReadOnly );
|
|
}
|
|
virtual ~KLimitedIODevice() {}
|
|
|
|
virtual bool open( TQ_OpenMode m ) {
|
|
//kdDebug(7005) << "KLimitedIODevice::open m=" << m << endl;
|
|
if ( m & IO_ReadOnly ) {
|
|
/*bool ok = false;
|
|
if ( m_dev->isOpen() )
|
|
ok = ( m_dev->mode() == IO_ReadOnly );
|
|
else
|
|
ok = m_dev->open( m );
|
|
if ( ok )*/
|
|
m_dev->at( m_start ); // No concurrent access !
|
|
}
|
|
else
|
|
kdWarning(7005) << "KLimitedIODevice::open only supports IO_ReadOnly!" << endl;
|
|
setState( IO_Open );
|
|
setMode( m );
|
|
return true;
|
|
}
|
|
virtual void close() {}
|
|
virtual void flush() {}
|
|
|
|
#ifdef USE_QT4
|
|
virtual qint64 size() const { return m_length; }
|
|
#else // USE_QT4
|
|
virtual Offset size() const { return m_length; }
|
|
#endif // USE_QT4
|
|
|
|
virtual TQT_TQIO_LONG tqreadBlock ( char * data, TQT_TQIO_ULONG maxlen )
|
|
{
|
|
maxlen = TQMIN( maxlen, m_length - at() ); // Apply upper limit
|
|
return m_dev->readBlock( data, maxlen );
|
|
}
|
|
virtual TQT_TQIO_LONG tqwriteBlock ( const char *, TQT_TQIO_ULONG ) { return -1; } // unsupported
|
|
virtual int putch( int ) { return -1; } // unsupported
|
|
|
|
virtual int getch() {
|
|
char c[2];
|
|
if ( tqreadBlock(c, 1) == -1)
|
|
return -1;
|
|
else
|
|
return c[0];
|
|
}
|
|
virtual int ungetch( int c ) { return m_dev->ungetch(c); } // ## apply lower limit ?
|
|
virtual Offset at() const { return m_dev->at() - m_start; }
|
|
virtual bool at( Offset pos ) {
|
|
Q_ASSERT( pos <= m_length );
|
|
pos = QMIN( pos, m_length ); // Apply upper limit
|
|
return m_dev->at( m_start + pos );
|
|
}
|
|
virtual bool atEnd() const { return m_dev->atEnd() || m_dev->at() >= m_start + m_length; }
|
|
private:
|
|
TQIODevice* m_dev;
|
|
TQ_ULONG m_start;
|
|
TQ_ULONG m_length;
|
|
};
|
|
|
|
#endif
|