turborand 0.7.0

Fast random number generators
Documentation

turborand

CI License Cargo Documentation

Fast random number generators.

turborand's internal implementations use Wyrand, a simple and fast generator but not cryptographically secure, and also ChaCha8, a cryptographically secure generator tuned to 8 rounds of the ChaCha algorithm in order to increase throughput considerably without sacrificing too much security, as per the recommendations set out in the Too Much Crypto paper.

Examples

use turborand::prelude::*;

let rand = Rng::new();

if rand.bool() {
    println!("Success! :D");
} else {
    println!("Failure... :(");
}

Sample a value from a list:

use turborand::prelude::*;

let rand = Rng::new();

let values = [1, 2, 3, 4, 5];

let value = rand.sample(&values);

Generate a vector with random values:

use turborand::prelude::*;
use std::iter::repeat_with;

let rand = Rng::new();

let values: Vec<_> = repeat_with(|| rand.f32()).take(10).collect();

Migration from 0.5 to 0.6

Version 0.6 introduces a major reworking of the crate, with code reorganised and also exposed more granularly via features. First things to note:

  • All major exports for the crate are now in the prelude module. Top level only exports the new traits for turborand.
  • Rng is now split into Rng and AtomicRng, no more top level generics that required exporting internal traits. State trait is now made private and no longer available to be implemented, as this was an internal implementation detail for WyRand.
  • All previous methods for Rng are now implemented in TurboCore, GenCore, SeededCore and TurboRand traits. These are part of the prelude so as long as they are included, all existing methods will work as expected.
  • Rng is now under a feature flag, wyrand. This is enabled by default however, unless default-features = false is applied on the dependency declaration in Cargo.toml.
  • Yeet the rng!, atomic_rng! macros, as these are no longer needed to manage the generics spam that has since been refactored out. Instead, use ::new(), ::default() or ::with_seed(seed) methods instead.

Migration from 0.6 to 0.7

Version 0.7 hasn't changed much except that the internals module is now fully private (so the State traits and CellState/AtomicState structs are no longer public). They are not accessible from the prelude any more. The removal of these from the public API thus constitutes a breaking change, leading to a new major version.

Also, the serialisation format of ChaChaRng has changed, so 0.7 is not compatible with older serialised structs. The plus side is also a flatter serialised format for ChaChaRng. Also, ChaChaRng is no longer backed by a Vec for caching generated entropy, now preferring to use an aligned array for better random number generation at the slight cost of initialisation/cloning performance and increased struct size. This means that the single heap allocation ChaChaRng needed is now reduced to zero.

License

Licensed under either of

at your option.