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