ya_rand/
romutrio.rs

1use crate::rng::{Generator, SeedableGenerator};
2use crate::util;
3
4/// Rust implementation of the RomuTrio PRNG.
5///
6/// This generator is extremely fast, high-quality, and small,
7/// but not cryptographically secure.
8///
9/// More information can be found at: <https://romu-random.org/>.
10#[derive(Debug, PartialEq, Eq)]
11pub struct RomuTrio {
12    state: [u64; 3],
13}
14
15impl Default for RomuTrio {
16    fn default() -> Self {
17        Self::new_with_seed(0)
18    }
19}
20
21impl SeedableGenerator for RomuTrio {
22    fn new_with_seed(seed: u64) -> Self {
23        let state = util::state_from_seed(seed);
24        let mut ret = Self { state };
25        let _discard_first = ret.u64();
26        ret
27    }
28}
29
30impl Generator for RomuTrio {
31    #[inline]
32    fn try_new() -> Result<Self, getrandom::Error> {
33        let state = util::state_from_entropy()?;
34        Ok(Self { state })
35    }
36
37    #[cfg_attr(feature = "inline", inline)]
38    fn u64(&mut self) -> u64 {
39        let tmp = self.state;
40        self.state[0] = tmp[2].wrapping_mul(15241094284759029579);
41        self.state[1] = tmp[1].wrapping_sub(tmp[0]).rotate_left(12);
42        self.state[2] = tmp[2].wrapping_sub(tmp[1]).rotate_left(44);
43        tmp[0]
44    }
45}
ya_rand/romutrio.rs

ya_rand/
romutrio.rs
