/* rng/rng.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 James Theiler, Brian Gough

 * 

 * 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 3 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

#include <config.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <gsl/gsl_errno.h>

#include <gsl/gsl_rng.h>

gsl_rng *

gsl_rng_alloc (const gsl_rng_type * T)

{

  gsl_rng *r = (gsl_rng *) malloc (sizeof (gsl_rng));

  if (r == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for rng struct",

                        GSL_ENOMEM, 0);

    };

  r->state = calloc (1, T->size);

  if (r->state == 0)

    {

      free (r);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for rng state",

                        GSL_ENOMEM, 0);

    };

  r->type = T;

  gsl_rng_set (r, gsl_rng_default_seed);        /* seed the generator */

  return r;

}

int

gsl_rng_memcpy (gsl_rng * dest, const gsl_rng * src)

{

  if (dest->type != src->type)

    {

      GSL_ERROR ("generators must be of the same type", GSL_EINVAL);

    }

  memcpy (dest->state, src->state, src->type->size);

  return GSL_SUCCESS;

}

gsl_rng *

gsl_rng_clone (const gsl_rng * q)

{

  gsl_rng *r = (gsl_rng *) malloc (sizeof (gsl_rng));

  if (r == 0)

    {

      GSL_ERROR_VAL ("failed to allocate space for rng struct",

                        GSL_ENOMEM, 0);

    };

  r->state = malloc (q->type->size);

  if (r->state == 0)

    {

      free (r);         /* exception in constructor, avoid memory leak */

      GSL_ERROR_VAL ("failed to allocate space for rng state",

                        GSL_ENOMEM, 0);

    };

  r->type = q->type;

  memcpy (r->state, q->state, q->type->size);

  return r;

}

void

gsl_rng_set (const gsl_rng * r, unsigned long int seed)

{

  (r->type->set) (r->state, seed);

}

unsigned long int

gsl_rng_max (const gsl_rng * r)

{

  return r->type->max;

}

unsigned long int

gsl_rng_min (const gsl_rng * r)

{

  return r->type->min;

}

const char *

gsl_rng_name (const gsl_rng * r)

{

  return r->type->name;

}

size_t

gsl_rng_size (const gsl_rng * r)

{

  return r->type->size;

}

void *

gsl_rng_state (const gsl_rng * r)

{

  return r->state;

}

void

gsl_rng_print_state (const gsl_rng * r)

{

  size_t i;

  unsigned char *p = (unsigned char *) (r->state);

  const size_t n = r->type->size;

  for (i = 0; i < n; i++)

    {

      /* FIXME: we're assuming that a char is 8 bits */

      printf ("%.2x", *(p + i));

    }

}

void

gsl_rng_free (gsl_rng * r)

{

  RETURN_IF_NULL (r);

  free (r->state);

  free (r);

}