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#![deny(missing_debug_implementations)]
#![cfg_attr(not(feature="std"), no_std)]
#![cfg_attr(all(feature="alloc", not(feature="std")), feature(alloc))]
#![cfg_attr(feature = "i128_support", feature(i128_type, i128))]
#[cfg(feature="std")] extern crate std as core;
#[cfg(all(feature = "alloc", not(feature="std")))] extern crate alloc;
use core::marker;
use core::mem;
#[cfg(feature="std")] use std::cell::RefCell;
#[cfg(feature="std")] use std::io;
#[cfg(feature="std")] use std::rc::Rc;
pub use jitter::JitterRng;
#[cfg(feature="std")] pub use os::OsRng;
pub use isaac::{IsaacRng, Isaac64Rng};
pub use chacha::ChaChaRng;
pub use prng::XorShiftRng;
#[cfg(target_pointer_width = "32")]
use prng::IsaacRng as IsaacWordRng;
#[cfg(target_pointer_width = "64")]
use prng::Isaac64Rng as IsaacWordRng;
use distributions::{Range, IndependentSample};
use distributions::range::SampleRange;
pub mod distributions;
pub mod jitter;
#[cfg(feature="std")] pub mod os;
#[cfg(feature="std")] pub mod read;
pub mod reseeding;
#[cfg(any(feature="std", feature = "alloc"))] pub mod seq;
pub mod chacha {
pub use prng::ChaChaRng;
}
pub mod isaac {
pub use prng::{IsaacRng, Isaac64Rng};
}
mod rand_impls;
mod prng;
pub trait Rand : Sized {
fn rand<R: Rng>(rng: &mut R) -> Self;
}
pub trait Rng {
fn next_u32(&mut self) -> u32;
fn next_u64(&mut self) -> u64 {
((self.next_u32() as u64) << 32) | (self.next_u32() as u64)
}
fn next_f32(&mut self) -> f32 {
const UPPER_MASK: u32 = 0x3F800000;
const LOWER_MASK: u32 = 0x7FFFFF;
let tmp = UPPER_MASK | (self.next_u32() & LOWER_MASK);
let result: f32 = unsafe { mem::transmute(tmp) };
result - 1.0
}
fn next_f64(&mut self) -> f64 {
const UPPER_MASK: u64 = 0x3FF0000000000000;
const LOWER_MASK: u64 = 0xFFFFFFFFFFFFF;
let tmp = UPPER_MASK | (self.next_u64() & LOWER_MASK);
let result: f64 = unsafe { mem::transmute(tmp) };
result - 1.0
}
fn fill_bytes(&mut self, dest: &mut [u8]) {
let mut count = 0;
let mut num = 0;
for byte in dest.iter_mut() {
if count == 0 {
num = self.next_u64();
count = 8;
}
*byte = (num & 0xff) as u8;
num >>= 8;
count -= 1;
}
}
#[inline(always)]
fn gen<T: Rand>(&mut self) -> T where Self: Sized {
Rand::rand(self)
}
fn gen_iter<'a, T: Rand>(&'a mut self) -> Generator<'a, T, Self> where Self: Sized {
Generator { rng: self, _marker: marker::PhantomData }
}
fn gen_range<T: PartialOrd + SampleRange>(&mut self, low: T, high: T) -> T where Self: Sized {
assert!(low < high, "Rng.gen_range called with low >= high");
Range::new(low, high).ind_sample(self)
}
fn gen_weighted_bool(&mut self, n: u32) -> bool where Self: Sized {
n <= 1 || self.gen_range(0, n) == 0
}
fn gen_ascii_chars<'a>(&'a mut self) -> AsciiGenerator<'a, Self> where Self: Sized {
AsciiGenerator { rng: self }
}
fn choose<'a, T>(&mut self, values: &'a [T]) -> Option<&'a T> where Self: Sized {
if values.is_empty() {
None
} else {
Some(&values[self.gen_range(0, values.len())])
}
}
fn choose_mut<'a, T>(&mut self, values: &'a mut [T]) -> Option<&'a mut T> where Self: Sized {
if values.is_empty() {
None
} else {
let len = values.len();
Some(&mut values[self.gen_range(0, len)])
}
}
fn shuffle<T>(&mut self, values: &mut [T]) where Self: Sized {
let mut i = values.len();
while i >= 2 {
i -= 1;
values.swap(i, self.gen_range(0, i + 1));
}
}
}
impl<'a, R: ?Sized> Rng for &'a mut R where R: Rng {
fn next_u32(&mut self) -> u32 {
(**self).next_u32()
}
fn next_u64(&mut self) -> u64 {
(**self).next_u64()
}
fn next_f32(&mut self) -> f32 {
(**self).next_f32()
}
fn next_f64(&mut self) -> f64 {
(**self).next_f64()
}
fn fill_bytes(&mut self, dest: &mut [u8]) {
(**self).fill_bytes(dest)
}
}
#[cfg(feature="std")]
impl<R: ?Sized> Rng for Box<R> where R: Rng {
fn next_u32(&mut self) -> u32 {
(**self).next_u32()
}
fn next_u64(&mut self) -> u64 {
(**self).next_u64()
}
fn next_f32(&mut self) -> f32 {
(**self).next_f32()
}
fn next_f64(&mut self) -> f64 {
(**self).next_f64()
}
fn fill_bytes(&mut self, dest: &mut [u8]) {
(**self).fill_bytes(dest)
}
}
#[derive(Debug)]
pub struct Generator<'a, T, R:'a> {
rng: &'a mut R,
_marker: marker::PhantomData<fn() -> T>,
}
impl<'a, T: Rand, R: Rng> Iterator for Generator<'a, T, R> {
type Item = T;
fn next(&mut self) -> Option<T> {
Some(self.rng.gen())
}
}
#[derive(Debug)]
pub struct AsciiGenerator<'a, R:'a> {
rng: &'a mut R,
}
impl<'a, R: Rng> Iterator for AsciiGenerator<'a, R> {
type Item = char;
fn next(&mut self) -> Option<char> {
const GEN_ASCII_STR_CHARSET: &'static [u8] =
b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz\
0123456789";
Some(*self.rng.choose(GEN_ASCII_STR_CHARSET).unwrap() as char)
}
}
pub trait SeedableRng<Seed>: Rng {
fn reseed(&mut self, Seed);
fn from_seed(seed: Seed) -> Self;
}
#[derive(Debug)]
pub struct Open01<F>(pub F);
#[derive(Debug)]
pub struct Closed01<F>(pub F);
#[derive(Copy, Clone, Debug)]
pub struct StdRng {
rng: IsaacWordRng,
}
impl StdRng {
#[cfg(feature="std")]
pub fn new() -> io::Result<StdRng> {
match OsRng::new() {
Ok(mut r) => Ok(StdRng { rng: r.gen() }),
Err(e1) => {
match JitterRng::new() {
Ok(mut r) => Ok(StdRng { rng: r.gen() }),
Err(_) => {
Err(e1)
}
}
}
}
}
}
impl Rng for StdRng {
#[inline]
fn next_u32(&mut self) -> u32 {
self.rng.next_u32()
}
#[inline]
fn next_u64(&mut self) -> u64 {
self.rng.next_u64()
}
}
impl<'a> SeedableRng<&'a [usize]> for StdRng {
fn reseed(&mut self, seed: &'a [usize]) {
self.rng.reseed(unsafe {mem::transmute(seed)})
}
fn from_seed(seed: &'a [usize]) -> StdRng {
StdRng { rng: SeedableRng::from_seed(unsafe {mem::transmute(seed)}) }
}
}
#[cfg(feature="std")]
pub fn weak_rng() -> XorShiftRng {
thread_rng().gen()
}
#[cfg(feature="std")]
#[derive(Debug)]
struct ThreadRngReseeder;
#[cfg(feature="std")]
impl reseeding::Reseeder<StdRng> for ThreadRngReseeder {
fn reseed(&mut self, rng: &mut StdRng) {
match StdRng::new() {
Ok(r) => *rng = r,
Err(e) => panic!("No entropy available: {}", e),
}
}
}
#[cfg(feature="std")]
const THREAD_RNG_RESEED_THRESHOLD: u64 = 32_768;
#[cfg(feature="std")]
type ThreadRngInner = reseeding::ReseedingRng<StdRng, ThreadRngReseeder>;
#[cfg(feature="std")]
#[derive(Clone, Debug)]
pub struct ThreadRng {
rng: Rc<RefCell<ThreadRngInner>>,
}
#[cfg(feature="std")]
pub fn thread_rng() -> ThreadRng {
thread_local!(static THREAD_RNG_KEY: Rc<RefCell<ThreadRngInner>> = {
let r = match StdRng::new() {
Ok(r) => r,
Err(e) => panic!("No entropy available: {}", e),
};
let rng = reseeding::ReseedingRng::new(r,
THREAD_RNG_RESEED_THRESHOLD,
ThreadRngReseeder);
Rc::new(RefCell::new(rng))
});
ThreadRng { rng: THREAD_RNG_KEY.with(|t| t.clone()) }
}
#[cfg(feature="std")]
impl Rng for ThreadRng {
fn next_u32(&mut self) -> u32 {
self.rng.borrow_mut().next_u32()
}
fn next_u64(&mut self) -> u64 {
self.rng.borrow_mut().next_u64()
}
#[inline]
fn fill_bytes(&mut self, bytes: &mut [u8]) {
self.rng.borrow_mut().fill_bytes(bytes)
}
}
#[cfg(feature="std")]
#[inline]
pub fn random<T: Rand>() -> T {
thread_rng().gen()
}
#[cfg(feature="std")]
#[inline(always)]
#[deprecated(since="0.4.0", note="renamed to seq::sample_iter")]
pub fn sample<T, I, R>(rng: &mut R, iterable: I, amount: usize) -> Vec<T>
where I: IntoIterator<Item=T>,
R: Rng,
{
seq::sample_iter(rng, iterable, amount)
.unwrap_or_else(|e| e)
}
#[cfg(test)]
mod test {
use super::{Rng, thread_rng, random, SeedableRng, StdRng, weak_rng};
use std::iter::repeat;
pub struct MyRng<R> { inner: R }
impl<R: Rng> Rng for MyRng<R> {
fn next_u32(&mut self) -> u32 {
fn next<T: Rng>(t: &mut T) -> u32 {
t.next_u32()
}
next(&mut self.inner)
}
}
pub fn rng() -> MyRng<::ThreadRng> {
MyRng { inner: ::thread_rng() }
}
struct ConstRng { i: u64 }
impl Rng for ConstRng {
fn next_u32(&mut self) -> u32 { self.i as u32 }
fn next_u64(&mut self) -> u64 { self.i }
}
pub fn iter_eq<I, J>(i: I, j: J) -> bool
where I: IntoIterator,
J: IntoIterator<Item=I::Item>,
I::Item: Eq
{
let mut i = i.into_iter();
let mut j = j.into_iter();
loop {
match (i.next(), j.next()) {
(Some(ref ei), Some(ref ej)) if ei == ej => { }
(None, None) => return true,
_ => return false,
}
}
}
#[test]
fn test_fill_bytes_default() {
let mut r = ConstRng { i: 0x11_22_33_44_55_66_77_88 };
let lengths = [0, 1, 2, 3, 4, 5, 6, 7,
80, 81, 82, 83, 84, 85, 86, 87];
for &n in lengths.iter() {
let mut v = repeat(0u8).take(n).collect::<Vec<_>>();
r.fill_bytes(&mut v);
for (i, &byte) in v.iter().enumerate() {
if byte == 0 {
panic!("byte {} of {} is zero", i, n)
}
}
}
}
#[test]
fn test_gen_range() {
let mut r = thread_rng();
for _ in 0..1000 {
let a = r.gen_range(-3, 42);
assert!(a >= -3 && a < 42);
assert_eq!(r.gen_range(0, 1), 0);
assert_eq!(r.gen_range(-12, -11), -12);
}
for _ in 0..1000 {
let a = r.gen_range(10, 42);
assert!(a >= 10 && a < 42);
assert_eq!(r.gen_range(0, 1), 0);
assert_eq!(r.gen_range(3_000_000, 3_000_001), 3_000_000);
}
}
#[test]
#[should_panic]
fn test_gen_range_panic_int() {
let mut r = thread_rng();
r.gen_range(5, -2);
}
#[test]
#[should_panic]
fn test_gen_range_panic_usize() {
let mut r = thread_rng();
r.gen_range(5, 2);
}
#[test]
fn test_gen_weighted_bool() {
let mut r = thread_rng();
assert_eq!(r.gen_weighted_bool(0), true);
assert_eq!(r.gen_weighted_bool(1), true);
}
#[test]
fn test_gen_ascii_str() {
let mut r = thread_rng();
assert_eq!(r.gen_ascii_chars().take(0).count(), 0);
assert_eq!(r.gen_ascii_chars().take(10).count(), 10);
assert_eq!(r.gen_ascii_chars().take(16).count(), 16);
}
#[test]
fn test_gen_vec() {
let mut r = thread_rng();
assert_eq!(r.gen_iter::<u8>().take(0).count(), 0);
assert_eq!(r.gen_iter::<u8>().take(10).count(), 10);
assert_eq!(r.gen_iter::<f64>().take(16).count(), 16);
}
#[test]
fn test_choose() {
let mut r = thread_rng();
assert_eq!(r.choose(&[1, 1, 1]).map(|&x|x), Some(1));
let v: &[isize] = &[];
assert_eq!(r.choose(v), None);
}
#[test]
fn test_shuffle() {
let mut r = thread_rng();
let empty: &mut [isize] = &mut [];
r.shuffle(empty);
let mut one = [1];
r.shuffle(&mut one);
let b: &[_] = &[1];
assert_eq!(one, b);
let mut two = [1, 2];
r.shuffle(&mut two);
assert!(two == [1, 2] || two == [2, 1]);
let mut x = [1, 1, 1];
r.shuffle(&mut x);
let b: &[_] = &[1, 1, 1];
assert_eq!(x, b);
}
#[test]
fn test_thread_rng() {
let mut r = thread_rng();
r.gen::<i32>();
let mut v = [1, 1, 1];
r.shuffle(&mut v);
let b: &[_] = &[1, 1, 1];
assert_eq!(v, b);
assert_eq!(r.gen_range(0, 1), 0);
}
#[test]
fn test_rng_trait_object() {
let mut rng = thread_rng();
{
let mut r = &mut rng as &mut Rng;
r.next_u32();
(&mut r).gen::<i32>();
let mut v = [1, 1, 1];
(&mut r).shuffle(&mut v);
let b: &[_] = &[1, 1, 1];
assert_eq!(v, b);
assert_eq!((&mut r).gen_range(0, 1), 0);
}
{
let mut r = Box::new(rng) as Box<Rng>;
r.next_u32();
r.gen::<i32>();
let mut v = [1, 1, 1];
r.shuffle(&mut v);
let b: &[_] = &[1, 1, 1];
assert_eq!(v, b);
assert_eq!(r.gen_range(0, 1), 0);
}
}
#[test]
fn test_random() {
let _n : usize = random();
let _f : f32 = random();
let _o : Option<Option<i8>> = random();
let _many : ((),
(usize,
isize,
Option<(u32, (bool,))>),
(u8, i8, u16, i16, u32, i32, u64, i64),
(f32, (f64, (f64,)))) = random();
}
#[test]
fn test_std_rng_seeded() {
let s = thread_rng().gen_iter::<usize>().take(256).collect::<Vec<usize>>();
let mut ra: StdRng = SeedableRng::from_seed(&s[..]);
let mut rb: StdRng = SeedableRng::from_seed(&s[..]);
assert!(iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
#[test]
fn test_std_rng_reseed() {
let s = thread_rng().gen_iter::<usize>().take(256).collect::<Vec<usize>>();
let mut r: StdRng = SeedableRng::from_seed(&s[..]);
let string1 = r.gen_ascii_chars().take(100).collect::<String>();
r.reseed(&s);
let string2 = r.gen_ascii_chars().take(100).collect::<String>();
assert_eq!(string1, string2);
}
#[test]
fn test_weak_rng() {
let s = weak_rng().gen_iter::<usize>().take(256).collect::<Vec<usize>>();
let mut ra: StdRng = SeedableRng::from_seed(&s[..]);
let mut rb: StdRng = SeedableRng::from_seed(&s[..]);
assert!(iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
}