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Diffstat (limited to 'rand/rand_xoshiro/src/xoshiro128starstar.rs')
| -rw-r--r-- | rand/rand_xoshiro/src/xoshiro128starstar.rs | 111 |
1 files changed, 0 insertions, 111 deletions
diff --git a/rand/rand_xoshiro/src/xoshiro128starstar.rs b/rand/rand_xoshiro/src/xoshiro128starstar.rs deleted file mode 100644 index 7af1e50..0000000 --- a/rand/rand_xoshiro/src/xoshiro128starstar.rs +++ /dev/null @@ -1,111 +0,0 @@ -// Copyright 2018 Developers of the Rand project. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -#[cfg(feature="serde1")] use serde::{Serialize, Deserialize}; -use rand_core::impls::{next_u64_via_u32, fill_bytes_via_next}; -use rand_core::le::read_u32_into; -use rand_core::{SeedableRng, RngCore, Error}; - -/// A xoshiro128** random number generator. -/// -/// The xoshiro128** algorithm is not suitable for cryptographic purposes, but -/// is very fast and has excellent statistical properties. -/// -/// The algorithm used here is translated from [the `xoshiro128starstar.c` -/// reference source code](http://xoshiro.di.unimi.it/xoshiro128starstar.c) by -/// David Blackman and Sebastiano Vigna. -#[derive(Debug, Clone)] -#[cfg_attr(feature="serde1", derive(Serialize, Deserialize))] -pub struct Xoshiro128StarStar { - s: [u32; 4], -} - -impl Xoshiro128StarStar { - /// Jump forward, equivalently to 2^64 calls to `next_u32()`. - /// - /// This can be used to generate 2^64 non-overlapping subsequences for - /// parallel computations. - /// - /// ``` - /// use rand_xoshiro::rand_core::SeedableRng; - /// use rand_xoshiro::Xoroshiro128StarStar; - /// - /// let rng1 = Xoroshiro128StarStar::seed_from_u64(0); - /// let mut rng2 = rng1.clone(); - /// rng2.jump(); - /// let mut rng3 = rng2.clone(); - /// rng3.jump(); - /// ``` - pub fn jump(&mut self) { - impl_jump!(u32, self, [0x8764000b, 0xf542d2d3, 0x6fa035c3, 0x77f2db5b]); - } -} - -impl SeedableRng for Xoshiro128StarStar { - type Seed = [u8; 16]; - - /// Create a new `Xoshiro128StarStar`. If `seed` is entirely 0, it will be - /// mapped to a different seed. - #[inline] - fn from_seed(seed: [u8; 16]) -> Xoshiro128StarStar { - deal_with_zero_seed!(seed, Self); - let mut state = [0; 4]; - read_u32_into(&seed, &mut state); - Xoshiro128StarStar { s: state } - } - - /// Seed a `Xoshiro128StarStar` from a `u64` using `SplitMix64`. - fn seed_from_u64(seed: u64) -> Xoshiro128StarStar { - from_splitmix!(seed) - } -} - -impl RngCore for Xoshiro128StarStar { - #[inline] - fn next_u32(&mut self) -> u32 { - let result_starstar = starstar_u64!(self.s[0]); - impl_xoshiro_u32!(self); - result_starstar - } - - #[inline] - fn next_u64(&mut self) -> u64 { - next_u64_via_u32(self) - } - - #[inline] - fn fill_bytes(&mut self, dest: &mut [u8]) { - fill_bytes_via_next(self, dest); - } - - #[inline] - fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { - self.fill_bytes(dest); - Ok(()) - } -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn reference() { - let mut rng = Xoshiro128StarStar::from_seed( - [1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0]); - // These values were produced with the reference implementation: - // http://xoshiro.di.unimi.it/xoshiro128starstar.c - let expected = [ - 5760, 40320, 70819200, 3297914139, 2480851620, 1792823698, - 4118739149, 1251203317, 1581886583, 1721184582, - ]; - for &e in &expected { - assert_eq!(rng.next_u32(), e); - } - } -} |