/*
* call-seq:
* GMP::RandState.new()
* GMP::RandState.new(:mt) #=> uses gmp_randinit_mt
* GMP::RandState.new(:lc_2exp, a, c, m2exp) #=> uses gmp_randinit_lc_2exp
* GMP::RandState.new(:lc_2exp_size, size) #=> uses gmp_randinit_lc_2exp_size
*
* Initializes a new Random State object. Multiple GMP::RandState objects can
* be instantiated. They may use different generators and the states
* are kept separate.
*/
VALUE r_gmprandstatesg_new(int argc, VALUE *argv, VALUE klass)
{
MP_RANDSTATE *rs_val;
VALUE rs;
VALUE algorithm, arg2, arg3, arg4;
ID algorithm_id = rb_intern("default");
MP_INT *a_val;
unsigned long c_val, m2exp_val;
unsigned long size_val;
int free_a_val = 0;
ID default_algorithm = rb_intern("default");
ID mt_algorithm = rb_intern("mt");
ID lc_2exp_algorithm = rb_intern("lc_2exp");
ID lc_2exp_size_algorithm = rb_intern("lc_2exp_size");
(void)klass;
mprandstate_make_struct(rs, rs_val);
rb_scan_args(argc, argv, "04", &algorithm, &arg2, &arg3, &arg4);
if (NIL_P(algorithm)) { algorithm_id = rb_intern("default"); } /* default value */
if (SYMBOL_P(algorithm)) { algorithm_id = rb_to_id(algorithm); }
if (algorithm_id == default_algorithm ||
algorithm_id == mt_algorithm) {
if (argc > 1)
rb_raise(rb_eArgError, "wrong # of arguments (%d for 0 or 1)", argc);
gmp_randinit_default(rs_val);
} else if (algorithm_id == lc_2exp_algorithm) {
if (argc != 4)
rb_raise(rb_eArgError, "wrong # of arguments (%d for 4)", argc);
if (GMPZ_P(arg2)) {
mpz_get_struct(arg2, a_val);
} else if (FIXNUM_P(arg2)) {
mpz_temp_alloc(a_val);
mpz_init_set_ui(a_val, FIX2INT(arg2));
free_a_val = 1;
} else if (BIGNUM_P(arg2)) {
mpz_temp_from_bignum(a_val, arg2);
free_a_val = 1;
} else {
typeerror_as(ZXB, "b");
}
c_val = NUM2LONG(arg3);
m2exp_val = NUM2LONG(arg4);
gmp_randinit_lc_2exp(rs_val, a_val, c_val, m2exp_val);
} else if (algorithm_id == lc_2exp_size_algorithm) {
if (argc != 2)
rb_raise(rb_eArgError, "wrong # of arguments (%d for 2)", argc);
size_val = NUM2LONG(arg2);
if (size_val > 128)
rb_raise(rb_eArgError, "size must be within [0..128]");
if (gmp_randinit_lc_2exp_size (rs_val, size_val) == 0)
rb_raise(rb_eArgError, "could not gmp_randinit_lc_2exp_size with %lu", size_val);
}
if (free_a_val) { mpz_temp_free(a_val); }
rb_obj_call_init(rs, argc, argv);
return rs;
}
/* Call (*func)() with various random number generators. */
void
call_rand_algs (void (*func) (const char *, gmp_randstate_ptr))
{
gmp_randstate_t rstate;
mpz_t a;
mpz_init (a);
gmp_randinit_default (rstate);
(*func) ("gmp_randinit_default", rstate);
gmp_randclear (rstate);
gmp_randinit_mt (rstate);
(*func) ("gmp_randinit_mt", rstate);
gmp_randclear (rstate);
gmp_randinit_lc_2exp_size (rstate, 8L);
(*func) ("gmp_randinit_lc_2exp_size 8", rstate);
gmp_randclear (rstate);
gmp_randinit_lc_2exp_size (rstate, 16L);
(*func) ("gmp_randinit_lc_2exp_size 16", rstate);
gmp_randclear (rstate);
gmp_randinit_lc_2exp_size (rstate, 128L);
(*func) ("gmp_randinit_lc_2exp_size 128", rstate);
gmp_randclear (rstate);
/* degenerate always zeros */
mpz_set_ui (a, 0L);
gmp_randinit_lc_2exp (rstate, a, 0L, 8L);
(*func) ("gmp_randinit_lc_2exp a=0 c=0 m=8", rstate);
gmp_randclear (rstate);
/* degenerate always FFs */
mpz_set_ui (a, 0L);
gmp_randinit_lc_2exp (rstate, a, 0xFFL, 8L);
(*func) ("gmp_randinit_lc_2exp a=0 c=0xFF m=8", rstate);
gmp_randclear (rstate);
mpz_clear (a);
}
int
gmp_randinit_lc_2exp_size (gmp_randstate_t rstate, unsigned long size)
{
const struct __gmp_rand_lc_scheme_struct *sp;
mpz_t a;
/* Pick a scheme. */
for (sp = __gmp_rand_lc_scheme; sp->m2exp != 0; sp++)
if (sp->m2exp / 2 >= size)
goto found;
return 0;
found:
/* Install scheme. */
mpz_init_set_str (a, sp->astr, 16);
gmp_randinit_lc_2exp (rstate, a, sp->c, sp->m2exp);
mpz_clear (a);
return 1;
}
int
check_params (void)
{
gmp_randstate_t r1, r2;
mpz_t a, b, m;
int i;
int result;
result = TRUE;
mpz_init (a);
mpz_init (b);
mpz_init (m);
if (result)
{
/* Test the consistency between urandomm and urandomb. */
gmp_randinit_default (r1);
gmp_randinit_default (r2);
gmp_randseed_ui (r1, 85L);
gmp_randseed_ui (r2, 85L);
mpz_set_ui (m, 0L);
mpz_setbit (m, 80L);
for (i = 0; i < 100; i++)
{
mpz_urandomm (a, r1, m);
mpz_urandomb (b, r2, 80L);
if (mpz_cmp (a, b) != 0)
{
result = FALSE;
printf ("mpz_urandomm != mpz_urandomb\n");
break;
}
}
gmp_randclear (r1);
gmp_randclear (r2);
}
if (result)
{
/* Test that mpz_urandomm returns the correct result with a
broken LC. */
mpz_set_ui (a, 0L);
gmp_randinit_lc_2exp (r1, a, 0xffL, 8L);
mpz_set_ui (m, 5L);
/* Warning: This code hangs in gmp 4.1 and below */
for (i = 0; i < 100; i++)
{
mpz_urandomm (a, r1, m);
if (mpz_cmp_ui (a, 2L) != 0)
{
result = FALSE;
gmp_printf ("mpz_urandomm returns %Zd instead of 2\n", a);
break;
}
}
gmp_randclear (r1);
}
if (result)
{
/* Test that the results are always in range for either
positive or negative values of m. */
gmp_randinit_default (r1);
mpz_set_ui (m, 5L);
mpz_set_si (b, -5L);
for (i = 0; i < 100; i++)
{
mpz_urandomm (a, r1, m);
if (mpz_cmp_ui (a, 5L) >= 0 || mpz_sgn (a) < 0)
{
result = FALSE;
gmp_printf ("Out-of-range or non-positive value: %Zd\n", a);
break;
}
mpz_urandomm (a, r1, b);
if (mpz_cmp_ui (a, 5L) >= 0 || mpz_sgn (a) < 0)
{
result = FALSE;
gmp_printf ("Out-of-range or non-positive value (from negative modulus): %Zd\n", a);
break;
}
}
gmp_randclear (r1);
}
if (result)
{
/* Test that m=1 forces always result=0. */
gmp_randinit_default (r1);
mpz_set_ui (m, 1L);
for (i = 0; i < 100; i++)
{
mpz_urandomm (a, r1, m);
if (mpz_sgn (a) != 0)
{
result = FALSE;
gmp_printf ("mpz_urandomm fails with m=1 (result=%Zd)\n", a);
break;
}
}
gmp_randclear (r1);
}
mpz_clear (a);
mpz_clear (b);
mpz_clear (m);
return result;
}
