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//
// Random.h
//
// Library: Foundation
// Package: Crypt
// Module: Random
//
// Definition of class Random.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
//
// Based on the FreeBSD random number generator.
// src/lib/libc/stdlib/random.c,v 1.25
//
// Copyright (c) 1983, 1993
// The Regents of the University of California. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 4. Neither the name of the University nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
#ifndef Foundation_Random_INCLUDED
#define Foundation_Random_INCLUDED
#include "Poco/Foundation.h"
namespace Poco {
class Foundation_API Random
/// A better random number generator.
/// Random implements a pseudo random number generator
/// (PRNG). The PRNG is a nonlinear additive
/// feedback random number generator using 256 bytes
/// of state information and a period of up to 2^69.
{
public:
enum Type
{
RND_STATE_0 = 8, /// linear congruential
RND_STATE_32 = 32, /// x**7 + x**3 + 1
RND_STATE_64 = 64, /// x**15 + x + 1
RND_STATE_128 = 128, /// x**31 + x**3 + 1
RND_STATE_256 = 256 /// x**63 + x + 1
};
Random(int stateSize = 256);
/// Creates and initializes the PRNG.
/// Specify either a state buffer size
/// (8 to 256 bytes) or one of the Type values.
~Random();
/// Destroys the PRNG.
void seed(UInt32 seed);
/// Seeds the pseudo random generator with the given seed.
void seed();
/// Seeds the pseudo random generator with a random seed
/// obtained from a RandomInputStream.
UInt32 next();
/// Returns the next 31-bit pseudo random number.
UInt32 next(UInt32 n);
/// Returns the next 31-bit pseudo random number modulo n.
char nextChar();
/// Returns the next pseudo random character.
bool nextBool();
/// Returns the next boolean pseudo random value.
float nextFloat();
/// Returns the next float pseudo random number between 0.0 and 1.0.
double nextDouble();
/// Returns the next double pseudo random number between 0.0 and 1.0.
protected:
void initState(UInt32 seed, char* arg_state, Int32 n);
static UInt32 goodRand(Int32 x);
private:
enum
{
MAX_TYPES = 5,
NSHUFF = 50
};
UInt32* _fptr;
UInt32* _rptr;
UInt32* _state;
int _randType;
int _randDeg;
int _randSep;
UInt32* _endPtr;
char* _pBuffer;
};
//
// inlines
//
inline UInt32 Random::next(UInt32 n)
{
return next() % n;
}
inline char Random::nextChar()
{
return char((next() >> 3) & 0xFF);
}
inline bool Random::nextBool()
{
return (next() & 0x1000) != 0;
}
inline float Random::nextFloat()
{
return float(next()) / 0x7FFFFFFF;
}
inline double Random::nextDouble()
{
return double(next()) / 0x7FFFFFFF;
}
} // namespace Poco
#endif // Foundation_Random_INCLUDED
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