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-rw-r--r--rand/rand_xoshiro/src/xoroshiro64starstar.rs17
1 files changed, 11 insertions, 6 deletions
diff --git a/rand/rand_xoshiro/src/xoroshiro64starstar.rs b/rand/rand_xoshiro/src/xoroshiro64starstar.rs
index a40baee..8e1aea1 100644
--- a/rand/rand_xoshiro/src/xoroshiro64starstar.rs
+++ b/rand/rand_xoshiro/src/xoroshiro64starstar.rs
@@ -6,13 +6,13 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
-use byteorder::{ByteOrder, LittleEndian};
+#[cfg(feature="serde1")] use serde::{Serialize, Deserialize};
use rand_core;
use rand_core::le::read_u32_into;
use rand_core::impls::{fill_bytes_via_next, next_u64_via_u32};
use rand_core::{RngCore, SeedableRng};
-/// A Xoroshiro64** random number generator.
+/// A xoroshiro64** random number generator.
///
/// The xoshiro64** algorithm is not suitable for cryptographic purposes, but
/// is very fast and has excellent statistical properties.
@@ -22,6 +22,7 @@ use rand_core::{RngCore, SeedableRng};
/// David Blackman and Sebastiano Vigna.
#[allow(missing_copy_implementations)]
#[derive(Debug, Clone)]
+#[cfg_attr(feature="serde1", derive(Serialize, Deserialize))]
pub struct Xoroshiro64StarStar {
s0: u32,
s1: u32,
@@ -68,11 +69,9 @@ impl SeedableRng for Xoroshiro64StarStar {
}
}
- /// Seed a `Xoroshiro64StarStar` from a `u64`.
+ /// Seed a `Xoroshiro64StarStar` from a `u64` using `SplitMix64`.
fn seed_from_u64(seed: u64) -> Xoroshiro64StarStar {
- let mut s = [0; 8];
- LittleEndian::write_u64(&mut s, seed);
- Xoroshiro64StarStar::from_seed(s)
+ from_splitmix!(seed)
}
}
@@ -93,4 +92,10 @@ mod tests {
assert_eq!(rng.next_u32(), e);
}
}
+
+ #[test]
+ fn zero_seed() {
+ let mut rng = Xoroshiro64StarStar::seed_from_u64(0);
+ assert_ne!(rng.next_u64(), 0);
+ }
}