cronoq-core 0.2.0

Sans-IO core engine of the cronoq elastic priority scheduler
Documentation 
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//! Small deterministic PRNG (SplitMix64) so engine behaviour is reproducible from a seed.

#[derive(Clone, Debug)]
pub struct Rng(u64);

impl Rng {
    pub fn new(seed: u64) -> Self {
        Rng(seed)
    }
    #[inline]
    pub fn next_u64(&mut self) -> u64 {
        self.0 = self.0.wrapping_add(0x9e37_79b9_7f4a_7c15);
        let mut z = self.0;
        z = (z ^ (z >> 30)).wrapping_mul(0xbf58_476d_1ce4_e5b9);
        z = (z ^ (z >> 27)).wrapping_mul(0x94d0_49bb_1331_11eb);
        z ^ (z >> 31)
    }
    /// Uniform in `[0, 1)`.
    #[inline]
    pub fn next_f64(&mut self) -> f64 {
        (self.next_u64() >> 11) as f64 / (1u64 << 53) as f64
    }
}