bitops.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* Copyright (c) 1998-2001 Sendmail, Inc. and its suppliers.
* All rights reserved.
* Copyright (c) 1983, 1995-1997 Eric P. Allman. All rights reserved.
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*
*
* $Id: bitops.h,v 1.2 2001/09/22 22:05:42 ca Exp $
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#ifndef SM_BITOPS_H
# define SM_BITOPS_H
/*
** Data structure for bit maps.
**
** Each bit in this map can be referenced by an ascii character.
** This is 256 possible bits, or 32 8-bit bytes.
*/
# define BITMAPBITS 256 /* number of bits in a bit map */
# define BYTEBITS 8 /* number of bits in a byte */
# define BITMAPBYTES (BITMAPBITS / BYTEBITS) /* number of bytes in bit map */
# define BITMAPMAX ((BITMAPBYTES / sizeof (int)) - 1)
/* internal macros */
/* make sure this index never leaves the allowed range: 0 to BITMAPMAX */
# define _BITWORD(bit) (((unsigned char)(bit) / (BYTEBITS * sizeof (int))) & BITMAPMAX)
# define _BITBIT(bit) ((unsigned int)1 << ((unsigned char)(bit) % (BYTEBITS * sizeof (int))))
typedef unsigned int BITMAP256[BITMAPBYTES / sizeof (int)];
/* properly case and truncate bit */
# define bitidx(bit) ((unsigned int) (bit) & 0xff)
/* test bit number N */
# define bitnset(bit, map) ((map)[_BITWORD(bit)] & _BITBIT(bit))
/* set bit number N */
# define setbitn(bit, map) (map)[_BITWORD(bit)] |= _BITBIT(bit)
/* clear bit number N */
# define clrbitn(bit, map) (map)[_BITWORD(bit)] &= ~_BITBIT(bit)
/* clear an entire bit map */
# define clrbitmap(map) memset((char *) map, '\0', BITMAPBYTES)
/* bit hacking */
# define bitset(bit, word) (((word) & (bit)) != 0)
#endif /* ! SM_BITOPS_H */