1/*	$NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $	*/
2
3/*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Randomizer for the dots program
34 */
35
36#include "defs.h"
37RCSID("$NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $")
38
39#include <time.h>
40#include <string.h>
41#include "random.h"
42
43RANDOM::RANDOM(size_t ns) :
44    _bs(ns)
45{
46    _bm = new char[(_bs >> 3) + 1];
47    clear();
48}
49
50RANDOM::~RANDOM()
51{
52    delete[] _bm;
53}
54
55// Reinitialize
56void RANDOM::clear(void)
57{
58    _nv = 0;
59    ::srand48(::time(NULL));
60    (void) ::memset(_bm, 0, (_bs >> 3) + 1);
61}
62
63// Return the next random value
64size_t RANDOM::operator() (void)
65{
66    // No more values
67    if (_nv == _bs)
68	return _bs;
69
70    for (;;) {
71	size_t r = ::lrand48();
72	size_t z = r % _bs;
73        if (!isset(z)) {
74	    set(z);
75	    _nv++;
76	    return z;
77	}
78    }
79}
80