[−][src]Crate nanorand
A library meant for fast, random number generation with quick compile time, and minimal dependencies.
Examples
Generating a number
use nanorand::{RNG, WyRand};
fn main() {
let mut rng = WyRand::new();
println!("Random number: {}", rng.generate::<u64>());
}
Generating a number in a range
use nanorand::{RNG, WyRand};
fn main() {
let mut rng = WyRand::new();
println!("Random number between 1 and 100: {}", rng.generate_range::<u64>(1, 100));
}
Shuffling a Vec
use nanorand::{RNG, WyRand};
fn main() {
let mut rng = WyRand::new();
let mut items = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
rng.shuffle(&mut items);
}
Why should I use this over...
rand
- The standard rand crate is a complex beast. It contains unsafe code in the core implementations, and while it has much more options than we do, that's kind of the point. We're straight to the point, while rand is everything and the kitchen sink.fastrand
,oorandom
,random-fast-rng
, orrandomize
- These are all minimal, zero-dep implementations of the PCG family of RNGs (Pcg32 and Pcg64). While these are decent, they are much slower than wyrand (which beats the speed of these Pcg32 implementations while providing 64 random bits), and do not provide CSPRNGs.getrandom
- The getrandom crate just provides OS entropy sources. It is not meant for random number generation. In fact, it is useful for seeding nanorand's RNGs on platforms where we can't do that ourselves.
RNG Implementations
RNG | nanorand type | Output Size | Cryptographically Secure | Speed | Notes | Original Implementation |
---|---|---|---|---|---|---|
wyrand | nanohash::WyRand | 64 bits (u64 ) | 🚫 | 4 GB/s | https://github.com/lemire/testingRNG/blob/master/source/wyrand.h | |
Pcg64 | nanohash::Pcg64 | 64 bits (u64 ) | 🚫 | 1 GB/s | https://github.com/rkern/pcg64 | |
ChaCha | nanohash::ChaCha | 512 bits ([u32; 16] ) | ✅ | 90 MB/s (ChaCha8), 40 MB/s (ChaCha20) | Currently only works in Nightly Rust, will work with Stable 1.47 (see rust#74060) | https://cr.yp.to/chacha.html |
Entropy Sources
- Unix-like (Linux, Android, macOS, iOS, FreeBSD, OpenBSD) - first
/dev/urandom
, else/dev/random
, else system time. (#[forbid(unsafe_code)]
) - Windows -
BCryptGenRandom
with system-preferred RNG. (#[deny(unsafe_code)]
)
Feature Flags
std
(default) - Enables Ruststd
lib features, such as seeding from OS entropy sources.wyrand
(default) - Enable the wyrand RNG.pcg64
(default) - Enable the Pcg64 RNG.chacha
(Nightly-only) - Enable the ChaCha RNG.rdseed
- On x86/x86_64 platforms, therdseed
intrinsic will be used when OS entropy isn't available.zeroize
- Implement the Zeroize trait for all RNGs.
Re-exports
pub use gen::*; |
pub use rand::*; |
Modules
crypto | Implementation of cryptography, for CSPRNGs. |
entropy | Sources for obtaining entropy. |
gen | Traits for generating types from an RNG. |
rand | RNG algorithms. |