wyrand 0.1.5

A fast & portable non-cryptographic pseudorandom number generator and hashing algorithm
Documentation

WyRand-rs

CI License Cargo Documentation

A fast & portable non-cryptographic pseudorandom number generator written in Rust, and optionally, the hashing algorithm as well.

The implementations for both the PRNG and hasher are based on the C reference implementation wyhash, a simple and fast hasher but not cryptographically secure. It's known to be extremely fast and performant while still having great statistical properties.

This crate provides both the v4.2 final implementation of the WyRand/WyHash algorithm, or the older final v4 implementation. The two versions have different outputs due to changes in the algorithm and also with the constants used. Currently by default, the older final v4 algorithm will be used. In the future, this will be changed to the newer algorithm to be the default, but the old implementation will remain for backwards compatibility reasons.

This crate can be used on its own or be integrated with rand_core/rand, and it is no-std compatible. Minimum compatible Rust version is 1.60. This crate is also implemented with no unsafe code via #![forbid(unsafe_code)].

Example

Generate a random value:

use wyrand::WyRand;

// Provide a seed to the PRNG
let mut rng = WyRand::new(Default::default());

let value = rng.rand();

Features

The crate will always export WyRand and will do so when set as default-features = false in the Cargo.toml. By default, it will have the rand_core, debug features enabled.

  • rand_core - Enables support for rand_core, implementing RngCore & SeedableRng on WyRand.
  • debug - Enables core::fmt::Debug implementation for WyRand/WyHash.
  • serde1 - Enables Serialize and Deserialize derives on WyRand.
  • hash - Enables core::hash::Hash implementation for WyRand.
  • wyhash - Enables WyHash, a fast & portable hashing algorithm. Based on the final v4 C implementation.
  • randomised_wyhash - Enables RandomisedWyHashBuilder, a means to source a randomised state for WyHash for use in collections like HashMap/HashSet. Enables wyhash feature if it is not already enabled.
  • v4_2 - Switches the PRNG/Hashing algorithms to use the final v4.2 implementation.

Building for WASM/Web

If you are using WyRand with rand_core and/or WyHash with randomised_wyhash then for building for the web/WASM, you'll need to configure getrandom to make use of the browser APIs in order to source entropy from. Add the following to your project Cargo.toml if your WASM builds target the web:

[target.'cfg(all(target_arch = "wasm32", target_os = "unknown"))'.dependencies]
getrandom = { version = "0.2", features = ["js"] }

License

Licensed under either of

at your option.