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tdeadmin/kdat/TapeDrive.h

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// KDat - a tar-based DAT archiver
// Copyright (C) 1998-2000 Sean Vyain, svyain@mail.tds.net
// Copyright (C) 2001-2002 Lawrence Widman, kdat@cardiothink.com
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#ifndef _TapeDrive_h_
#define _TapeDrive_h_
#include <tqobject.h>
class Tape;
/**
* @short An OO interface to the tape drive.
*/
class TapeDrive : public TQObject {
Q_OBJECT
TQ_OBJECT
int _fd;
bool _readOnly;
Tape* _tape;
char* _writeBuf;
char* _readBuf;
int _writeBufIdx;
int _readBufIdx;
static TapeDrive* _instance;
TapeDrive();
public:
/**
* Destroy the tape drive (figuratively speaking, of course).
*/
~TapeDrive();
/**
* Get a reference to the single instance of the tape drive object.
*
* @return A pointer to the tape drive object.
*/
static TapeDrive* instance();
/**
* Close the tape device. If data was written to the tape drive, then this
* will also cause a single end-of-file marker to be written out. This is
* the preferred way to write an end-of-file marker to the tape.
*/
void close();
/**
* Physically eject the tape from the drive. Some tape drives do not
* support this operation well.
*/
void eject();
/**
* If there is unwritten data in the buffer, it will be flushed out. This
* method is called when necessary by the other tape drive methods.
*/
void flush();
/**
* Get the current tape file number. The first tape file is number 0.
*
* @return >= 0 on success, -1 on failure.
*/
int getFile();
/**
* Get the current tape block number within the current file. The first
* tape block number within a file is 0.
*
* @return >= 0 on success, -1 on failure.
*/
int getBlock();
/**
* Determine whether the tape can be written to.
*
* @return TRUE if the tape cannot be written to, otherwise FALSE.
*/
bool isReadOnly();
/**
* Determine whether there is a tape in the drive.
*
* @return TRUE if there is a tape, otherwise FALSE.
*/
bool isTapePresent();
/**
* Load the tape into the drive.
*
* @return TRUE on success, otherwise FALSE.
*/
bool load();
/**
* Lock the tape in the drive, so that it cannot be ejected manually by the
* user. Not all tape drives support this operation.
*
* @return TRUE on success, otherwise FALSE.
*/
bool lock();
/**
* Skip over one or more end-of-file markers on the tape. The tape is
* positioned just after the last skipped end-of-file marker.
*
* @param count The number of end-of-file markers to skip over.
*
* @return TRUE on success, otherwise FALSE.
*/
bool nextFile( int count );
/**
* Skip over one or more tape blocks within the current tape file.
*
* @param count The number of tape blocks to skip over.
*
* @return TRUE on success, otherwise FALSE.
*/
bool nextRecord( int count );
/**
* Open the tape device for reading and writing. If this fails, try
* opening the tape device for reading only. Check isReadOnly() to see
* if the tape device was opened for reading and writing.
*
* @return TRUE if the tape device was opened for reading and/or writing,
* otherwise FALSE.
*/
void open();
/**
* Determine wether the tape is positioned just after an end-of-file
* marker.
*
* @return TRUE if the tape is positioned after an end-of-file marker,
* otherwise FALSE.
*/
bool pastEOF();
/**
* Backspace over one or more end-of-file markers. The tape is positioned
* just before the last end-of-file marker.
*
* @param count The number of end-of-file markers to backspace over.
*
* @return TRUE on success, otherwise FALSE.
*/
bool prevFile( int count );
/**
* Backspace over one or more tape blocks.
*
* @param count The number of tape block to backspace over.
*
* @return TRUE on success, otherwise FALSE.
*/
bool prevRecord( int count );
/**
* Read data from the tape.
*
* @param buf The buffer to read into.
* @param len The number of bytes to read.
*
* @return The actual number of bytes read, or -1 on failure.
*/
int read( char* buf, int len );
/**
* Read the KDat tape header (if there is one), and get the index
* associated with the tape.
*
* @return A pointer to the tape index, or NULL if the tape does not have
* a KDat header.
*/
Tape* readHeader();
/**
* Rewind the tape.
*
* @return TRUE on success, otherwise FALSE.
*/
bool rewind();
/**
* Move the tape to the given tar block within the given tape file. This
* method will intelligently move the tape to the desired position.
*
* @param file The tape file number.
* @param tarBlock The desired tar block (NOT tape block).
*
* @return TRUE on success, otherwise FALSE.
*/
bool seek( int file, int tarBlock );
/**
* Set the hardware tape block size.
*
* @param blockSize The new tape block size in bytes.
*
* @return TRUE on success, otherwise FALSE.
*/
bool setBlockSize( int blockSize );
/**
* Unlock the tape in the drive, so that it can be ejected manually by the
* user. Not all tape drives support this operation.
*
* @return TRUE on success, otherwise FALSE.
*/
bool unlock();
/**
* Write data to the tape.
*
* @param buf The buffer to write from.
* @param len The number of bytes to write.
*
* @return The actual number of bytes written, or -1 on failure.
*/
int write( const char* buf, int len );
signals:
/**
* This signal is emitted for one-line, informational messages.
*
* @param msg The informational message.
*/
void sigStatus( const TQString & msg );
};
#endif