/*
 * Copyright (C) 2018 John Forecast. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN FORECAST "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef __TAPE_H__
#define __TAPE_H__

/*
 * Metadata markers
 */
#define ST_EOM          0xFFFFFFFF      /* end of medium */
#define ST_GAP          0xFFFFFFFE      /* erase gap */
#define ST_TM           0x00000000      /* tape mark */

/*
 * Special code for reporting errors. If actually read from a container
 * file, this would be considered an error.
 */
#define ST_FAIL         0xFEFEFEFE

/*
 * Record length field layout
 */
#define ST_ERROR        0x80000000      /* record contains an error */
#define ST_MBZ          0x7F000000      /* must be zero */
#define ST_LENGTH       0x00FFFFFF      /* record length */

/*
 * Data in the .tap container file is rounded up to an even number of bytes
 */
#define RECLEN(c)       (((c) + 1) & ~1)

extern int tapeVerify(FILE *, off_t *);
extern off_t tapeGetPosition(FILE *);
extern int tapeSetPosition(FILE *, off_t);
extern uint32_t tapeSkipRecordF(FILE *);
extern uint32_t tapeSkipRecordR(FILE *);
extern uint32_t tapePeekRecordLength(FILE *);
extern uint32_t tapeReadRecord(FILE *, void *, int);
extern uint32_t tapeReadRecordLength(FILE *);
extern uint32_t tapeReadRecordLengthReverse(FILE *);
extern int tapeWriteRecord(FILE *, void *, int);
extern int tapeWriteEOM(FILE *, int);
extern int tapeWriteTM(FILE *);
extern int tapeEOM(FILE *, off_t *);
extern void tapeRewind(FILE *);
extern int tapeSkipForward(FILE *, unsigned long);
extern int tapeSkipReverse(FILE *, unsigned long);

#endif
