c_cpp/etc/calc/zrandom.h

   1 /*
   2  * zrandom - Blum-Blum-Shub pseudo-random generator
   3  *
   4  * Copyright (C) 1999-2007  Landon Curt Noll
   5  *
   6  * Calc is open software; you can redistribute it and/or modify it under
   7  * the terms of the version 2.1 of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation.
   9  *
  10  * Calc is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
  13  * Public License for more details.
  14  *
  15  * A copy of version 2.1 of the GNU Lesser General Public License is
  16  * distributed with calc under the filename COPYING-LGPL.  You should have
  17  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  * @(#) $Revision: 30.1 $
  21  * @(#) $Id: zrandom.h,v 30.1 2007/03/16 11:09:46 chongo Exp $
  22  * @(#) $Source: /usr/local/src/bin/calc/RCS/zrandom.h,v $
  23  *
  24  * Under source code control:   1997/02/15 04:01:56
  25  * File existed as early as:    1997
  26  *
  27  * chongo <was here> /\oo/\     http://www.isthe.com/chongo/
  28  * Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
  29  */
  30
  31
  32 #if !defined(__ZRANDOM_H__)
  33 #define __ZRANDOM_H__
  34
  35
  36 #if defined(CALC_SRC)   /* if we are building from the calc source tree */
  37 # include "value.h"
  38 # include "have_const.h"
  39 #else
  40 # include <calc/value.h>
  41 # include <calc/have_const.h>
  42 #endif
  43
  44
  45 /*
  46  * Blum generator state
  47  *
  48  * The size of the buffer implies that a turn of the quadratic residue crank
  49  * will never yield as many at the than the number of bits in a HALF.  At
  50  * most this implies that a turn can yield no more than 15 bits when BASEB==16
  51  * or 31 bits when BASEB==32.  Should we deal with a excessively large
  52  * Blum modulus (>=2^16 bits long for BASEB==16, >=2^32 bits for BASEB==32)
  53  * the higher order random bits will be tossed.  This is not a loss as
  54  * regular sub-segments of the sequence are just as random.  It only means
  55  * that excessively large Blum modulus values waste CPU time.
  56  */
  57 struct random {
  58         int seeded;     /* 1 => state has been seeded */
  59         int bits;       /* number of unused bits in buffer */
  60         int loglogn;    /* int(log2(log2(n))), bits produced per turn */
  61         HALF buffer;    /* unused random bits from previous call */
  62         HALF mask;      /* mask for the log2(log2(n)) lower bits of r */
  63         ZVALUE n;       /* Blum modulus */
  64         ZVALUE r;       /* Blum quadratic residue */
  65 };
  66
  67
  68 /*
  69  * Blum constants
  70  */
  71 #define BLUM_PREGEN 20  /* number of non-default predefined Blum generators */
  72
  73
  74 /*
  75  * Blum generator function declarations
  76  */
  77 E_FUNC RANDOM *zsrandom1(CONST ZVALUE seed, BOOL need_ret);
  78 E_FUNC RANDOM *zsrandom2(CONST ZVALUE seed, CONST ZVALUE newn);
  79 E_FUNC RANDOM *zsrandom4(CONST ZVALUE seed,
  80                          CONST ZVALUE ip, CONST ZVALUE iq, long trials);
  81 E_FUNC RANDOM *zsetrandom(CONST RANDOM *state);
  82 E_FUNC void zrandomskip(long count);
  83 E_FUNC void zrandom(long count, ZVALUE *res);
  84 E_FUNC void zrandom(long count, ZVALUE *res);
  85 E_FUNC void zrandomrange(CONST ZVALUE low, CONST ZVALUE beyond, ZVALUE *res);
  86 E_FUNC long irandom(long s);
  87 E_FUNC RANDOM *randomcopy(CONST RANDOM *random);
  88 E_FUNC void randomfree(RANDOM *random);
  89 E_FUNC BOOL randomcmp(CONST RANDOM *s1, CONST RANDOM *s2);
  90 E_FUNC void randomprint(CONST RANDOM *state, int flags);
  91 E_FUNC void random_libcalc_cleanup(void);
  92
  93
  94 #endif /* !__ZRANDOM_H__ */