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Diffstat (limited to 'contrib/sendmail/include/sm/bitops.h')
-rw-r--r-- | contrib/sendmail/include/sm/bitops.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/contrib/sendmail/include/sm/bitops.h b/contrib/sendmail/include/sm/bitops.h new file mode 100644 index 0000000..44778ba --- /dev/null +++ b/contrib/sendmail/include/sm/bitops.h @@ -0,0 +1,57 @@ +/* + * 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 $ + */ + +#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 */ |