text: /* Copyright (C) 2007 MySQL AB & Michael Widenius
  
     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; version 2 of the License.
  
     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 */
  
  #include "mysys_priv.h"
  #include <m_string.h>
  
  /*
    Initialize random generator
  
    NOTES
      MySQL's password checks depends on this, so don't do any changes
      that changes the random numbers that are generated!
  */
  
  void my_rnd_init(struct my_rnd_struct *rand_st, ulong seed1, ulong seed2)
  {
  #ifdef HAVE_purify
    bzero((char*) rand_st,sizeof(*rand_st));      /* Avoid UMC varnings */
  #endif
    rand_st->max_value= 0x3FFFFFFFL;
    rand_st->max_value_dbl=(double) rand_st->max_value;
    rand_st->seed1=seed1%rand_st->max_value ;
    rand_st->seed2=seed2%rand_st->max_value;
  }
  
  
  /*
    Generate random number.
  
    SYNOPSIS
      my_rnd()
      rand_st    INOUT  Structure used for number generation
      
    RETURN VALUE
      generated pseudo random number
  */
  
  double my_rnd(struct my_rnd_struct *rand_st)
  {
    rand_st->seed1=(rand_st->seed1*3+rand_st->seed2) % rand_st->max_value;
    rand_st->seed2=(rand_st->seed1+rand_st->seed2+33) % rand_st->max_value;
    return (((double) rand_st->seed1)/rand_st->max_value_dbl);
  }
  