aboutsummaryrefslogtreecommitdiff
path: root/rand/rand_xoshiro/src/xoshiro512starstar.rs
diff options
context:
space:
mode:
authorDaniel Mueller <deso@posteo.net>2019-01-16 17:26:30 -0800
committerDaniel Mueller <deso@posteo.net>2019-01-16 17:26:30 -0800
commit8350ac6afb2d678b74581000a6aafe1994b72231 (patch)
tree2330da01a806921b3849c9e64d2b9f506495e2c0 /rand/rand_xoshiro/src/xoshiro512starstar.rs
parentd6652b913b33e432a748187f9f5623cec1e9926e (diff)
downloadnitrocli-8350ac6afb2d678b74581000a6aafe1994b72231.tar.gz
nitrocli-8350ac6afb2d678b74581000a6aafe1994b72231.tar.bz2
Update nitrokey crate to 0.3.3
This change updates the nitrokey crate to version 0.3.3. Along with that change we update rand to 0.6.4 because rand 0.6.1 does not yet contain a publicly accessible rand_os. Note that we no longer require all crates in rand's workspace, but only rand_os and rand_core, which is a significant reduction in the number of lines of code compiled. Import subrepo nitrokey/:nitrokey at 7cf747d56ddc0b7eeedc3caf36dcc909907a171c Import subrepo rand/:rand at 4336232dda03323634b10ec72ddf27914aebc3a2
Diffstat (limited to 'rand/rand_xoshiro/src/xoshiro512starstar.rs')
-rw-r--r--rand/rand_xoshiro/src/xoshiro512starstar.rs124
1 files changed, 124 insertions, 0 deletions
diff --git a/rand/rand_xoshiro/src/xoshiro512starstar.rs b/rand/rand_xoshiro/src/xoshiro512starstar.rs
new file mode 100644
index 0000000..1a33f0a
--- /dev/null
+++ b/rand/rand_xoshiro/src/xoshiro512starstar.rs
@@ -0,0 +1,124 @@
+// 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.
+
+use rand_core::impls::fill_bytes_via_next;
+use rand_core::le::read_u64_into;
+use rand_core::{SeedableRng, RngCore, Error};
+
+use Seed512;
+
+/// A xoshiro512** random number generator.
+///
+/// The xoshiro512** algorithm is not suitable for cryptographic purposes, but
+/// is very fast and has excellent statistical properties.
+///
+/// The algorithm used here is translated from [the `xoshiro512starstar.c`
+/// reference source code](http://xoshiro.di.unimi.it/xoshiro512starstar.c) by
+/// David Blackman and Sebastiano Vigna.
+#[derive(Debug, Clone)]
+pub struct Xoshiro512StarStar {
+ s: [u64; 8],
+}
+
+impl Xoshiro512StarStar {
+ /// Jump forward, equivalently to 2^256 calls to `next_u64()`.
+ ///
+ /// This can be used to generate 2^256 non-overlapping subsequences for
+ /// parallel computations.
+ ///
+ /// ```
+ /// # extern crate rand;
+ /// # extern crate rand_xoshiro;
+ /// # fn main() {
+ /// use rand::SeedableRng;
+ /// use rand_xoshiro::Xoshiro512StarStar;
+ ///
+ /// let rng1 = Xoshiro512StarStar::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!(u64, self, [
+ 0x33ed89b6e7a353f9, 0x760083d7955323be, 0x2837f2fbb5f22fae,
+ 0x4b8c5674d309511c, 0xb11ac47a7ba28c25, 0xf1be7667092bcc1c,
+ 0x53851efdb6df0aaf, 0x1ebbc8b23eaf25db
+ ]);
+ }
+}
+
+
+impl SeedableRng for Xoshiro512StarStar {
+ type Seed = Seed512;
+
+ /// Create a new `Xoshiro512StarStar`. If `seed` is entirely 0, it will be
+ /// mapped to a different seed.
+ #[inline]
+ fn from_seed(seed: Seed512) -> Xoshiro512StarStar {
+ deal_with_zero_seed!(seed, Self);
+ let mut state = [0; 8];
+ read_u64_into(&seed.0, &mut state);
+ Xoshiro512StarStar { s: state }
+ }
+
+ /// Seed a `Xoshiro512StarStar` from a `u64` using `SplitMix64`.
+ fn seed_from_u64(seed: u64) -> Xoshiro512StarStar {
+ from_splitmix!(seed)
+ }
+}
+
+impl RngCore for Xoshiro512StarStar {
+ #[inline]
+ fn next_u32(&mut self) -> u32 {
+ self.next_u64() as u32
+ }
+
+ #[inline]
+ fn next_u64(&mut self) -> u64 {
+ let result_starstar = starstar_u64!(self.s[1]);
+ impl_xoshiro_large!(self);
+ result_starstar
+ }
+
+ #[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 = Xoshiro512StarStar::from_seed(Seed512(
+ [1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0,
+ 3, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0,
+ 5, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0,
+ 7, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0]));
+ // These values were produced with the reference implementation:
+ // http://xoshiro.di.unimi.it/xoshiro512starstar.c
+ let expected = [
+ 11520, 0, 23040, 23667840, 144955163520, 303992986974289920,
+ 25332796375735680, 296904390158016, 13911081092387501979,
+ 15304787717237593024,
+ ];
+ for &e in &expected {
+ assert_eq!(rng.next_u64(), e);
+ }
+ }
+}