usr/src/cmd/sendmail/include/sm/bitops.h

   1 /*
   2  * Copyright (c) 1998-2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
   5  * Copyright (c) 1988, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * By using this file, you agree to the terms and conditions set
   9  * forth in the LICENSE file which can be found at the top level of
  10  * the sendmail distribution.
  11  *
  12  *
  13  *      $Id: bitops.h,v 1.2 2001/09/22 22:05:42 ca Exp $
  14  */
  15
  16 #pragma ident   "%Z%%M% %I%     %E% SMI"
  17
  18 #ifndef SM_BITOPS_H
  19 # define SM_BITOPS_H
  20
  21 /*
  22 **  Data structure for bit maps.
  23 **
  24 **      Each bit in this map can be referenced by an ascii character.
  25 **      This is 256 possible bits, or 32 8-bit bytes.
  26 */
  27
  28 # define BITMAPBITS     256     /* number of bits in a bit map */
  29 # define BYTEBITS       8       /* number of bits in a byte */
  30 # define BITMAPBYTES    (BITMAPBITS / BYTEBITS) /* number of bytes in bit map */
  31 # define BITMAPMAX      ((BITMAPBYTES / sizeof (int)) - 1)
  32
  33 /* internal macros */
  34
  35 /* make sure this index never leaves the allowed range: 0 to BITMAPMAX */
  36 # define _BITWORD(bit)  (((unsigned char)(bit) / (BYTEBITS * sizeof (int))) & BITMAPMAX)
  37 # define _BITBIT(bit)   ((unsigned int)1 << ((unsigned char)(bit) % (BYTEBITS * sizeof (int))))
  38
  39 typedef unsigned int    BITMAP256[BITMAPBYTES / sizeof (int)];
  40
  41 /* properly case and truncate bit */
  42 # define bitidx(bit)            ((unsigned int) (bit) & 0xff)
  43
  44 /* test bit number N */
  45 # define bitnset(bit, map)      ((map)[_BITWORD(bit)] & _BITBIT(bit))
  46
  47 /* set bit number N */
  48 # define setbitn(bit, map)      (map)[_BITWORD(bit)] |= _BITBIT(bit)
  49
  50 /* clear bit number N */
  51 # define clrbitn(bit, map)      (map)[_BITWORD(bit)] &= ~_BITBIT(bit)
  52
  53 /* clear an entire bit map */
  54 # define clrbitmap(map)         memset((char *) map, '\0', BITMAPBYTES)
  55
  56 /* bit hacking */
  57 # define bitset(bit, word)      (((word) & (bit)) != 0)
  58
  59 #endif /* ! SM_BITOPS_H */