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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/rand-0.7.3/src/rngs/std.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/rand-0.7.3/src/rngs/std.rs')
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+// 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.
+
+//! The standard RNG
+
+use crate::{CryptoRng, Error, RngCore, SeedableRng};
+
+#[cfg(all(any(test, feature = "std"), not(target_os = "emscripten")))]
+pub(crate) use rand_chacha::ChaCha20Core as Core;
+#[cfg(all(any(test, feature = "std"), target_os = "emscripten"))]
+pub(crate) use rand_hc::Hc128Core as Core;
+
+#[cfg(not(target_os = "emscripten"))] use rand_chacha::ChaCha20Rng as Rng;
+#[cfg(target_os = "emscripten")] use rand_hc::Hc128Rng as Rng;
+
+/// The standard RNG. The PRNG algorithm in `StdRng` is chosen to be efficient
+/// on the current platform, to be statistically strong and unpredictable
+/// (meaning a cryptographically secure PRNG).
+///
+/// The current algorithm used is the ChaCha block cipher with 20 rounds.
+/// This may change as new evidence of cipher security and performance
+/// becomes available.
+///
+/// The algorithm is deterministic but should not be considered reproducible
+/// due to dependence on configuration and possible replacement in future
+/// library versions. For a secure reproducible generator, we recommend use of
+/// the [rand_chacha] crate directly.
+///
+/// [rand_chacha]: https://crates.io/crates/rand_chacha
+#[derive(Clone, Debug)]
+pub struct StdRng(Rng);
+
+impl RngCore for StdRng {
+ #[inline(always)]
+ fn next_u32(&mut self) -> u32 {
+ self.0.next_u32()
+ }
+
+ #[inline(always)]
+ fn next_u64(&mut self) -> u64 {
+ self.0.next_u64()
+ }
+
+ #[inline(always)]
+ fn fill_bytes(&mut self, dest: &mut [u8]) {
+ self.0.fill_bytes(dest);
+ }
+
+ #[inline(always)]
+ fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> {
+ self.0.try_fill_bytes(dest)
+ }
+}
+
+impl SeedableRng for StdRng {
+ type Seed = <Rng as SeedableRng>::Seed;
+
+ #[inline(always)]
+ fn from_seed(seed: Self::Seed) -> Self {
+ StdRng(Rng::from_seed(seed))
+ }
+
+ #[inline(always)]
+ fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error> {
+ Rng::from_rng(rng).map(StdRng)
+ }
+}
+
+impl CryptoRng for StdRng {}
+
+
+#[cfg(test)]
+mod test {
+ use crate::rngs::StdRng;
+ use crate::{RngCore, SeedableRng};
+
+ #[test]
+ fn test_stdrng_construction() {
+ // Test value-stability of StdRng. This is expected to break any time
+ // the algorithm is changed.
+ #[rustfmt::skip]
+ let seed = [1,0,0,0, 23,0,0,0, 200,1,0,0, 210,30,0,0,
+ 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
+
+ #[cfg(any(feature = "stdrng_strong", not(feature = "stdrng_fast")))]
+ let target = [3950704604716924505, 5573172343717151650];
+ #[cfg(all(not(feature = "stdrng_strong"), feature = "stdrng_fast"))]
+ let target = [10719222850664546238, 14064965282130556830];
+
+ let mut rng0 = StdRng::from_seed(seed);
+ let x0 = rng0.next_u64();
+
+ let mut rng1 = StdRng::from_rng(rng0).unwrap();
+ let x1 = rng1.next_u64();
+
+ assert_eq!([x0, x1], target);
+ }
+}