From fffd213c8cba2135afda493d797c41c10354770e Mon Sep 17 00:00:00 2001 From: Othmar Gsenger Date: Sat, 12 Apr 2008 11:38:42 +0000 Subject: big svn cleanup --- src/Sockets/RandomNumber.h | 202 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 src/Sockets/RandomNumber.h (limited to 'src/Sockets/RandomNumber.h') diff --git a/src/Sockets/RandomNumber.h b/src/Sockets/RandomNumber.h new file mode 100644 index 0000000..376db43 --- /dev/null +++ b/src/Sockets/RandomNumber.h @@ -0,0 +1,202 @@ +/** + * @author Adam McLaurin + * @date September 2006 + */ +/* +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License +as published by the Free Software Foundation; either version 2 +of the License, or (at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +*/ + +#ifndef _SOCKET_RandomNumber_H +#define _SOCKET_RandomNumber_H + +#include "sockets-config.h" +#include + +#ifdef SOCKETS_NAMESPACE +namespace SOCKETS_NAMESPACE { +#endif + +/** + * The following class uses an xorshift algorithm proposed in the following + * paper: + * - http://www.jstatsoft.org/v08/i14/xorshift.pdf + * + * The algorithm provides a PRNG with a period of (2^128)-1 + * + * This PRNG is *not* intended for cryptographic purposes + */ +class RandomNumber +{ + +public: + /** + * Default constructor + * + * NOTE: Internal seeds are set to defaults proposed by the paper + */ + RandomNumber(bool time_shuffle = false); + + /** + * Custom constructor + * + * @param x_seed X seed + * + * @param y_seed Y seed + * + * @param z_seed Z seed + * + * @param w_seed W seed + */ + RandomNumber( + unsigned long int x_seed, + unsigned long int y_seed, + unsigned long int z_seed, + unsigned long int w_seed); + + /** + * Destructor + */ + ~RandomNumber(); + + // public methods + + /** + * Reset internal state to initial seed values + */ + void reset(); + + /** + * Cast operator to obtain current random value in the PRNG + * + * @return Current random value in the PRNG + */ + operator unsigned long int() const; + + /** + * Go to the next number in the PRNG sequence + * + * NOTE: This method is a slightly modified implementation of the xor128() + * function proposed in the paper + * + * @return Next value produced by the PRNG (after updating) + */ + unsigned long int next(); + + /** + * Skip ahead in the PRNG sequence by a given number of iterations + * + * @param s Number of iterations to skip ahead + * + * @return Value produced by the PRNG after skipping ahead in the sequence + */ + unsigned long int skip(unsigned long int s); + + /** + * Obtain all the initial seeds for this PRNG + * + * @param x_seed X seed (output) + * + * @param y_seed Y seed (output) + * + * @param z_seed Z seed (output) + * + * @param w_seed W seed (output) + */ + void getSeed( + unsigned long int& x_seed, + unsigned long int& y_seed, + unsigned long int& z_seed, + unsigned long int& w_seed); + + /** + * Get the maximum possible random number from this PRNG + * + * @return Maximum possible random number from this PRNG + */ + static unsigned long int max_random(); + + // public constants + + /** + * Default x-seed as proposed by the paper + */ + static const unsigned long int X_SEED_DEFAULT; + + /** + * Default y-seed as proposed by the paper + */ + static const unsigned long int Y_SEED_DEFAULT; + + /** + * Default z-seed as proposed by the paper + */ + static const unsigned long int Z_SEED_DEFAULT; + + /** + * Default w-seed as proposed by the paper + */ + static const unsigned long int W_SEED_DEFAULT; + +private: + /** + * X seed + */ + unsigned long int mXSeed; + + /** + * Y seed + */ + unsigned long int mYSeed; + + /** + * Z seed + */ + unsigned long int mZSeed; + + /** + * W seed + */ + unsigned long int mWSeed; + + /** + * X value + */ + unsigned long int mX; + + /** + * Y value + */ + unsigned long int mY; + + /** + * Z value + */ + unsigned long int mZ; + + /** + * W value + * + * NOTE: This is the externally-visible next value produced by the PRNG + */ + unsigned long int mW; + +}; + +#ifdef SOCKETS_NAMESPACE +} // namespace SOCKETS_NAMESPACE { +#endif + +#endif // _SOCKETS_RandomNumber_H + -- cgit v1.2.3