Class: PCGRandom

Inherits:
Object
  • Object
show all
Defined in:
lib/pcg_random/version.rb,
ext/pcg_random/pcg_random.c

Constant Summary collapse

VERSION = 
"0.1.4"
DEFAULT_SEED_BYTES = 
INT2FIX(DEFAULT_SEED_BYTES)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object

Internal - Initialize the requested instance using a pre-allocated ruby object (TypedStruct). Sets the instance variables and relevant accessor methods where applicable.



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# File 'ext/pcg_random/pcg_random.c', line 110

static VALUE
pcg_func_init(int argc, VALUE *argv, VALUE self)
{
    VALUE seed;
    uint64_t cseeds[2];
    pcg_rb_rand_t* rand_data = pcg_get_rand_type(self);

    if(argc == 0)
    {
        seed = DEFAULT_SEED_VALUE;
    }
    else
    {
        rb_scan_args(argc, argv, "01", &seed);
    }

    rb_integer_pack(seed, (void *) cseeds, 2, sizeof(uint64_t), 0,
        INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER);

    rand_data->seed.val     = seed;
    rand_data->seed.state   = cseeds[0];
    rand_data->seed.seq     = cseeds[1];
    pcg32_srandom_r(rand_data->rng, cseeds[0], cseeds[1]);

    /* Add & set private instance variables */
    rb_iv_set(self, "@seed", seed);
    rb_iv_set(self, "state", LONG2NUM(rand_data->seed.state));
    rb_iv_set(self, "sequence", LONG2NUM(rand_data->seed.seq));
    return self;
}

Instance Attribute Details

#seed ⇒ Object (readonly)

Class Method Details

.new_seed ⇒ Object

Returns a 16-byte integer that stores the seed value used to seed the initial state and sequence for the PCG generator.



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# File 'ext/pcg_random/pcg_seed.c', line 13

VALUE
pcg_func_new_seed(VALUE self)
{
    return DEFAULT_SEED_VALUE;
}

.raw_seed(byte_size) ⇒ Object

Generates a random seed string represented as a sequence of bytes

Parameters:

  • byte_size —

    Size of the bytestring to generate



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# File 'ext/pcg_random/pcg_seed.c', line 24

VALUE
pcg_func_raw_seed(VALUE self, VALUE byte_size)
{
    unsigned long n = NUM2ULONG(byte_size);
    if(n == 0)
    {
        return rb_str_new2("\0");
    }
    return pcg_raw_seed_bytestr(n);
}