80 lines
2.2 KiB
C++
80 lines
2.2 KiB
C++
/* $NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $ */
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/*-
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* Copyright (c) 2003 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Christos Zoulas.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Randomizer for the dots program
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*/
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#include "defs.h"
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RCSID("$NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $")
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#include <time.h>
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#include <string.h>
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#include "random.h"
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RANDOM::RANDOM(size_t ns) :
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_bs(ns)
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{
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_bm = new char[(_bs >> 3) + 1];
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clear();
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}
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RANDOM::~RANDOM()
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{
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delete[] _bm;
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}
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// Reinitialize
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void RANDOM::clear(void)
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{
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_nv = 0;
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::srand48(::time(NULL));
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(void) ::memset(_bm, 0, (_bs >> 3) + 1);
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}
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// Return the next random value
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size_t RANDOM::operator() (void)
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{
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// No more values
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if (_nv == _bs)
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return _bs;
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for (;;) {
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size_t r = ::lrand48();
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size_t z = r % _bs;
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if (!isset(z)) {
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set(z);
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_nv++;
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return z;
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}
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}
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}
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