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#ifndef _ZFTAPE_RW_H
#define _ZFTAPE_RW_H
/*
* Copyright (C) 1996, 1997 Claus-Justus Heine.
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, 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; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-rw.h,v $
* $Revision: 1.2 $
* $Date: 1997/10/05 19:19:09 $
*
* This file contains the definitions for the read and write
* functions for the QIC-117 floppy-tape driver for Linux.
*
*/
#include "../zftape/zftape-buffers.h"
#define SEGMENTS_PER_TAPE (ft_segments_per_track * ft_tracks_per_tape)
/* QIC-113 Rev. G says that `a maximum of 63488 raw bytes may be
* compressed into a single frame'.
* Maybe we should stick to 32kb to make it more `beautiful'
*/
#define ZFT_MAX_BLK_SZ (62*1024) /* bytes */
#if !defined(CONFIG_ZFT_DFLT_BLK_SZ)
# define CONFIG_ZFT_DFLT_BLK_SZ (10*1024) /* bytes, default of gnu tar */
#elif CONFIG_ZFT_DFLT_BLK_SZ == 0
# undef CONFIG_ZFT_DFLT_BLK_SZ
# define CONFIG_ZFT_DFLT_BLK_SZ 1
#elif (CONFIG_ZFT_DFLT_BLK_SZ % 1024) != 0
# error CONFIG_ZFT_DFLT_BLK_SZ must be 1 or a multiple of 1024
#endif
/* The *optional* compression routines need some overhead per tape
* block for their purposes. Instead of asking the actual compression
* implementation how much it needs, we restrict this overhead to be
* maximal of ZFT_CMPT_OVERHEAD size. We need this for EOT
* conditions. The tape is assumed to be logical at EOT when the
* distance from the physical EOT is less than
* one tape block + ZFT_CMPR_OVERHEAD
*/
#define ZFT_CMPR_OVERHEAD 16 /* bytes */
typedef enum
{
zft_idle = 0,
zft_reading,
zft_writing,
} zft_status_enum;
typedef struct /* all values measured in bytes */
{
int seg_pos; /* segment currently positioned at */
int seg_byte_pos; /* offset in current segment */
__s64 tape_pos; /* real offset from BOT */
__s64 volume_pos; /* pos. in uncompressed data stream in
* current volume
*/
} zft_position;
extern zft_position zft_pos;
extern __u8 *zft_deblock_buf;
extern __u8 *zft_hseg_buf;
extern int zft_deblock_segment;
extern zft_status_enum zft_io_state;
extern int zft_header_changed;
extern int zft_qic113; /* conform to old specs. and old zftape */
extern int zft_use_compression;
extern unsigned int zft_blk_sz;
extern __s64 zft_capacity;
extern unsigned int zft_written_segments;
extern int zft_label_changed;
/* zftape-rw.c exported functions
*/
extern unsigned int zft_get_seg_sz(unsigned int segment);
extern void zft_set_flags(unsigned int minor_unit);
extern int zft_calc_seg_byte_coord(int *seg_byte_pos, __s64 tape_pos);
extern __s64 zft_calc_tape_pos(int segment);
extern __s64 zft_get_capacity(void);
extern void zft_update_label(__u8 *buffer);
extern int zft_erase(void);
extern int zft_verify_write_segments(unsigned int segment,
__u8 *data, size_t size, __u8 *buffer);
extern unsigned int zft_get_time(void);
#endif /* _ZFTAPE_RW_H */
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