729060dbb9
`Times::times` was always a second-class loop because it did not support the `break` and `continue` operations. Its playful appeal was then lost after `do` was disabled for closures. It's time to let this one go.
536 lines
17 KiB
Rust
536 lines
17 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
//! The ISAAC random number generator.
|
|
|
|
use rand::{Rng, SeedableRng, OSRng};
|
|
use iter::{Iterator, range, range_step, Repeat};
|
|
use option::{None, Some};
|
|
use vec::{raw, MutableVector, ImmutableVector};
|
|
use mem;
|
|
|
|
static RAND_SIZE_LEN: u32 = 8;
|
|
static RAND_SIZE: u32 = 1 << RAND_SIZE_LEN;
|
|
|
|
/// A random number generator that uses the ISAAC algorithm[1].
|
|
///
|
|
/// The ISAAC algorithm is generally accepted as suitable for
|
|
/// cryptographic purposes, but this implementation has not be
|
|
/// verified as such. Prefer a generator like `OSRng` that defers to
|
|
/// the operating system for cases that need high security.
|
|
///
|
|
/// [1]: Bob Jenkins, [*ISAAC: A fast cryptographic random number
|
|
/// generator*](http://www.burtleburtle.net/bob/rand/isaacafa.html)
|
|
pub struct IsaacRng {
|
|
priv cnt: u32,
|
|
priv rsl: [u32, .. RAND_SIZE],
|
|
priv mem: [u32, .. RAND_SIZE],
|
|
priv a: u32,
|
|
priv b: u32,
|
|
priv c: u32
|
|
}
|
|
static EMPTY: IsaacRng = IsaacRng {
|
|
cnt: 0,
|
|
rsl: [0, .. RAND_SIZE],
|
|
mem: [0, .. RAND_SIZE],
|
|
a: 0, b: 0, c: 0
|
|
};
|
|
|
|
impl IsaacRng {
|
|
/// Create an ISAAC random number generator with a random seed.
|
|
pub fn new() -> IsaacRng {
|
|
let mut rng = EMPTY;
|
|
|
|
unsafe {
|
|
let ptr = rng.rsl.as_mut_ptr();
|
|
|
|
raw::mut_buf_as_slice(ptr as *mut u8, mem::size_of_val(&rng.rsl), |slice| {
|
|
OSRng::new().fill_bytes(slice);
|
|
})
|
|
}
|
|
|
|
rng.init(true);
|
|
rng
|
|
}
|
|
|
|
/// Create an ISAAC random number generator using the default
|
|
/// fixed seed.
|
|
pub fn new_unseeded() -> IsaacRng {
|
|
let mut rng = EMPTY;
|
|
rng.init(false);
|
|
rng
|
|
}
|
|
|
|
/// Initialises `self`. If `use_rsl` is true, then use the current value
|
|
/// of `rsl` as a seed, otherwise construct one algorithmically (not
|
|
/// randomly).
|
|
fn init(&mut self, use_rsl: bool) {
|
|
let mut a = 0x9e3779b9;
|
|
let mut b = a;
|
|
let mut c = a;
|
|
let mut d = a;
|
|
let mut e = a;
|
|
let mut f = a;
|
|
let mut g = a;
|
|
let mut h = a;
|
|
|
|
macro_rules! mix(
|
|
() => {{
|
|
a^=b<<11; d+=a; b+=c;
|
|
b^=c>>2; e+=b; c+=d;
|
|
c^=d<<8; f+=c; d+=e;
|
|
d^=e>>16; g+=d; e+=f;
|
|
e^=f<<10; h+=e; f+=g;
|
|
f^=g>>4; a+=f; g+=h;
|
|
g^=h<<8; b+=g; h+=a;
|
|
h^=a>>9; c+=h; a+=b;
|
|
}}
|
|
);
|
|
|
|
for _ in range(0, 4) { mix!(); }
|
|
|
|
if use_rsl {
|
|
macro_rules! memloop (
|
|
($arr:expr) => {{
|
|
for i in range_step(0u32, RAND_SIZE, 8) {
|
|
a+=$arr[i ]; b+=$arr[i+1];
|
|
c+=$arr[i+2]; d+=$arr[i+3];
|
|
e+=$arr[i+4]; f+=$arr[i+5];
|
|
g+=$arr[i+6]; h+=$arr[i+7];
|
|
mix!();
|
|
self.mem[i ]=a; self.mem[i+1]=b;
|
|
self.mem[i+2]=c; self.mem[i+3]=d;
|
|
self.mem[i+4]=e; self.mem[i+5]=f;
|
|
self.mem[i+6]=g; self.mem[i+7]=h;
|
|
}
|
|
}}
|
|
);
|
|
|
|
memloop!(self.rsl);
|
|
memloop!(self.mem);
|
|
} else {
|
|
for i in range_step(0u32, RAND_SIZE, 8) {
|
|
mix!();
|
|
self.mem[i ]=a; self.mem[i+1]=b;
|
|
self.mem[i+2]=c; self.mem[i+3]=d;
|
|
self.mem[i+4]=e; self.mem[i+5]=f;
|
|
self.mem[i+6]=g; self.mem[i+7]=h;
|
|
}
|
|
}
|
|
|
|
self.isaac();
|
|
}
|
|
|
|
/// Refills the output buffer (`self.rsl`)
|
|
#[inline]
|
|
fn isaac(&mut self) {
|
|
self.c += 1;
|
|
// abbreviations
|
|
let mut a = self.a;
|
|
let mut b = self.b + self.c;
|
|
|
|
static MIDPOINT: uint = RAND_SIZE as uint / 2;
|
|
|
|
macro_rules! ind (($x:expr) => {
|
|
self.mem[($x >> 2) & (RAND_SIZE - 1)]
|
|
});
|
|
macro_rules! rngstep(
|
|
($j:expr, $shift:expr) => {{
|
|
let base = $j;
|
|
let mix = if $shift < 0 {
|
|
a >> -$shift as uint
|
|
} else {
|
|
a << $shift as uint
|
|
};
|
|
|
|
let x = self.mem[base + mr_offset];
|
|
a = (a ^ mix) + self.mem[base + m2_offset];
|
|
let y = ind!(x) + a + b;
|
|
self.mem[base + mr_offset] = y;
|
|
|
|
b = ind!(y >> RAND_SIZE_LEN) + x;
|
|
self.rsl[base + mr_offset] = b;
|
|
}}
|
|
);
|
|
|
|
let r = [(0, MIDPOINT), (MIDPOINT, 0)];
|
|
for &(mr_offset, m2_offset) in r.iter() {
|
|
for i in range_step(0u, MIDPOINT, 4) {
|
|
rngstep!(i + 0, 13);
|
|
rngstep!(i + 1, -6);
|
|
rngstep!(i + 2, 2);
|
|
rngstep!(i + 3, -16);
|
|
}
|
|
}
|
|
|
|
self.a = a;
|
|
self.b = b;
|
|
self.cnt = RAND_SIZE;
|
|
}
|
|
}
|
|
|
|
impl Rng for IsaacRng {
|
|
#[inline]
|
|
fn next_u32(&mut self) -> u32 {
|
|
if self.cnt == 0 {
|
|
// make some more numbers
|
|
self.isaac();
|
|
}
|
|
self.cnt -= 1;
|
|
self.rsl[self.cnt]
|
|
}
|
|
}
|
|
|
|
impl<'a> SeedableRng<&'a [u32]> for IsaacRng {
|
|
fn reseed(&mut self, seed: &'a [u32]) {
|
|
// make the seed into [seed[0], seed[1], ..., seed[seed.len()
|
|
// - 1], 0, 0, ...], to fill rng.rsl.
|
|
let seed_iter = seed.iter().map(|&x| x).chain(Repeat::new(0u32));
|
|
|
|
for (rsl_elem, seed_elem) in self.rsl.mut_iter().zip(seed_iter) {
|
|
*rsl_elem = seed_elem;
|
|
}
|
|
self.cnt = 0;
|
|
self.a = 0;
|
|
self.b = 0;
|
|
self.c = 0;
|
|
|
|
self.init(true);
|
|
}
|
|
|
|
/// Create an ISAAC random number generator with a seed. This can
|
|
/// be any length, although the maximum number of elements used is
|
|
/// 256 and any more will be silently ignored. A generator
|
|
/// constructed with a given seed will generate the same sequence
|
|
/// of values as all other generators constructed with that seed.
|
|
fn from_seed(seed: &'a [u32]) -> IsaacRng {
|
|
let mut rng = EMPTY;
|
|
rng.reseed(seed);
|
|
rng
|
|
}
|
|
}
|
|
|
|
|
|
static RAND_SIZE_64_LEN: uint = 8;
|
|
static RAND_SIZE_64: uint = 1 << RAND_SIZE_64_LEN;
|
|
|
|
/// A random number generator that uses ISAAC-64[1], the 64-bit
|
|
/// variant of the ISAAC algorithm.
|
|
///
|
|
/// The ISAAC algorithm is generally accepted as suitable for
|
|
/// cryptographic purposes, but this implementation has not be
|
|
/// verified as such. Prefer a generator like `OSRng` that defers to
|
|
/// the operating system for cases that need high security.
|
|
///
|
|
/// [1]: Bob Jenkins, [*ISAAC: A fast cryptographic random number
|
|
/// generator*](http://www.burtleburtle.net/bob/rand/isaacafa.html)
|
|
pub struct Isaac64Rng {
|
|
priv cnt: uint,
|
|
priv rsl: [u64, .. RAND_SIZE_64],
|
|
priv mem: [u64, .. RAND_SIZE_64],
|
|
priv a: u64,
|
|
priv b: u64,
|
|
priv c: u64,
|
|
}
|
|
|
|
static EMPTY_64: Isaac64Rng = Isaac64Rng {
|
|
cnt: 0,
|
|
rsl: [0, .. RAND_SIZE_64],
|
|
mem: [0, .. RAND_SIZE_64],
|
|
a: 0, b: 0, c: 0,
|
|
};
|
|
|
|
impl Isaac64Rng {
|
|
/// Create a 64-bit ISAAC random number generator with a random
|
|
/// seed.
|
|
pub fn new() -> Isaac64Rng {
|
|
let mut rng = EMPTY_64;
|
|
|
|
unsafe {
|
|
let ptr = rng.rsl.as_mut_ptr();
|
|
|
|
raw::mut_buf_as_slice(ptr as *mut u8, mem::size_of_val(&rng.rsl), |slice| {
|
|
OSRng::new().fill_bytes(slice);
|
|
})
|
|
}
|
|
|
|
rng.init(true);
|
|
rng
|
|
}
|
|
|
|
/// Create a 64-bit ISAAC random number generator using the
|
|
/// default fixed seed.
|
|
pub fn new_unseeded() -> Isaac64Rng {
|
|
let mut rng = EMPTY_64;
|
|
rng.init(false);
|
|
rng
|
|
}
|
|
|
|
/// Initialises `self`. If `use_rsl` is true, then use the current value
|
|
/// of `rsl` as a seed, otherwise construct one algorithmically (not
|
|
/// randomly).
|
|
fn init(&mut self, use_rsl: bool) {
|
|
macro_rules! init (
|
|
($var:ident) => (
|
|
let mut $var = 0x9e3779b97f4a7c13;
|
|
)
|
|
);
|
|
init!(a); init!(b); init!(c); init!(d);
|
|
init!(e); init!(f); init!(g); init!(h);
|
|
|
|
macro_rules! mix(
|
|
() => {{
|
|
a-=e; f^=h>>9; h+=a;
|
|
b-=f; g^=a<<9; a+=b;
|
|
c-=g; h^=b>>23; b+=c;
|
|
d-=h; a^=c<<15; c+=d;
|
|
e-=a; b^=d>>14; d+=e;
|
|
f-=b; c^=e<<20; e+=f;
|
|
g-=c; d^=f>>17; f+=g;
|
|
h-=d; e^=g<<14; g+=h;
|
|
}}
|
|
);
|
|
|
|
for _ in range(0, 4) { mix!(); }
|
|
if use_rsl {
|
|
macro_rules! memloop (
|
|
($arr:expr) => {{
|
|
for i in range(0, RAND_SIZE_64 / 8).map(|i| i * 8) {
|
|
a+=$arr[i ]; b+=$arr[i+1];
|
|
c+=$arr[i+2]; d+=$arr[i+3];
|
|
e+=$arr[i+4]; f+=$arr[i+5];
|
|
g+=$arr[i+6]; h+=$arr[i+7];
|
|
mix!();
|
|
self.mem[i ]=a; self.mem[i+1]=b;
|
|
self.mem[i+2]=c; self.mem[i+3]=d;
|
|
self.mem[i+4]=e; self.mem[i+5]=f;
|
|
self.mem[i+6]=g; self.mem[i+7]=h;
|
|
}
|
|
}}
|
|
);
|
|
|
|
memloop!(self.rsl);
|
|
memloop!(self.mem);
|
|
} else {
|
|
for i in range(0, RAND_SIZE_64 / 8).map(|i| i * 8) {
|
|
mix!();
|
|
self.mem[i ]=a; self.mem[i+1]=b;
|
|
self.mem[i+2]=c; self.mem[i+3]=d;
|
|
self.mem[i+4]=e; self.mem[i+5]=f;
|
|
self.mem[i+6]=g; self.mem[i+7]=h;
|
|
}
|
|
}
|
|
|
|
self.isaac64();
|
|
}
|
|
|
|
/// Refills the output buffer (`self.rsl`)
|
|
fn isaac64(&mut self) {
|
|
self.c += 1;
|
|
// abbreviations
|
|
let mut a = self.a;
|
|
let mut b = self.b + self.c;
|
|
static MIDPOINT: uint = RAND_SIZE_64 / 2;
|
|
static MP_VEC: [(uint, uint), .. 2] = [(0,MIDPOINT), (MIDPOINT, 0)];
|
|
macro_rules! ind (
|
|
($x:expr) => {
|
|
*self.mem.unsafe_ref(($x as uint >> 3) & (RAND_SIZE_64 - 1))
|
|
}
|
|
);
|
|
macro_rules! rngstep(
|
|
($j:expr, $shift:expr) => {{
|
|
let base = base + $j;
|
|
let mix = a ^ (if $shift < 0 {
|
|
a >> -$shift as uint
|
|
} else {
|
|
a << $shift as uint
|
|
});
|
|
let mix = if $j == 0 {!mix} else {mix};
|
|
|
|
unsafe {
|
|
let x = *self.mem.unsafe_ref(base + mr_offset);
|
|
a = mix + *self.mem.unsafe_ref(base + m2_offset);
|
|
let y = ind!(x) + a + b;
|
|
self.mem.unsafe_set(base + mr_offset, y);
|
|
|
|
b = ind!(y >> RAND_SIZE_64_LEN) + x;
|
|
self.rsl.unsafe_set(base + mr_offset, b);
|
|
}
|
|
}}
|
|
);
|
|
|
|
for &(mr_offset, m2_offset) in MP_VEC.iter() {
|
|
for base in range(0, MIDPOINT / 4).map(|i| i * 4) {
|
|
rngstep!(0, 21);
|
|
rngstep!(1, -5);
|
|
rngstep!(2, 12);
|
|
rngstep!(3, -33);
|
|
}
|
|
}
|
|
|
|
self.a = a;
|
|
self.b = b;
|
|
self.cnt = RAND_SIZE_64;
|
|
}
|
|
}
|
|
|
|
impl Rng for Isaac64Rng {
|
|
// FIXME #7771: having next_u32 like this should be unnecessary
|
|
#[inline]
|
|
fn next_u32(&mut self) -> u32 {
|
|
self.next_u64() as u32
|
|
}
|
|
|
|
#[inline]
|
|
fn next_u64(&mut self) -> u64 {
|
|
if self.cnt == 0 {
|
|
// make some more numbers
|
|
self.isaac64();
|
|
}
|
|
self.cnt -= 1;
|
|
unsafe { *self.rsl.unsafe_ref(self.cnt) }
|
|
}
|
|
}
|
|
|
|
impl<'a> SeedableRng<&'a [u64]> for Isaac64Rng {
|
|
fn reseed(&mut self, seed: &'a [u64]) {
|
|
// make the seed into [seed[0], seed[1], ..., seed[seed.len()
|
|
// - 1], 0, 0, ...], to fill rng.rsl.
|
|
let seed_iter = seed.iter().map(|&x| x).chain(Repeat::new(0u64));
|
|
|
|
for (rsl_elem, seed_elem) in self.rsl.mut_iter().zip(seed_iter) {
|
|
*rsl_elem = seed_elem;
|
|
}
|
|
self.cnt = 0;
|
|
self.a = 0;
|
|
self.b = 0;
|
|
self.c = 0;
|
|
|
|
self.init(true);
|
|
}
|
|
|
|
/// Create an ISAAC random number generator with a seed. This can
|
|
/// be any length, although the maximum number of elements used is
|
|
/// 256 and any more will be silently ignored. A generator
|
|
/// constructed with a given seed will generate the same sequence
|
|
/// of values as all other generators constructed with that seed.
|
|
fn from_seed(seed: &'a [u64]) -> Isaac64Rng {
|
|
let mut rng = EMPTY_64;
|
|
rng.reseed(seed);
|
|
rng
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use super::*;
|
|
use rand::{Rng, SeedableRng, OSRng};
|
|
use prelude::*;
|
|
use vec;
|
|
|
|
#[test]
|
|
fn test_rng_32_rand_seeded() {
|
|
let s = OSRng::new().gen_vec::<u32>(256);
|
|
let mut ra: IsaacRng = SeedableRng::from_seed(s.as_slice());
|
|
let mut rb: IsaacRng = SeedableRng::from_seed(s.as_slice());
|
|
assert_eq!(ra.gen_ascii_str(100u), rb.gen_ascii_str(100u));
|
|
}
|
|
#[test]
|
|
fn test_rng_64_rand_seeded() {
|
|
let s = OSRng::new().gen_vec::<u64>(256);
|
|
let mut ra: Isaac64Rng = SeedableRng::from_seed(s.as_slice());
|
|
let mut rb: Isaac64Rng = SeedableRng::from_seed(s.as_slice());
|
|
assert_eq!(ra.gen_ascii_str(100u), rb.gen_ascii_str(100u));
|
|
}
|
|
|
|
#[test]
|
|
fn test_rng_32_seeded() {
|
|
let seed = &[1, 23, 456, 7890, 12345];
|
|
let mut ra: IsaacRng = SeedableRng::from_seed(seed);
|
|
let mut rb: IsaacRng = SeedableRng::from_seed(seed);
|
|
assert_eq!(ra.gen_ascii_str(100u), rb.gen_ascii_str(100u));
|
|
}
|
|
#[test]
|
|
fn test_rng_64_seeded() {
|
|
let seed = &[1, 23, 456, 7890, 12345];
|
|
let mut ra: Isaac64Rng = SeedableRng::from_seed(seed);
|
|
let mut rb: Isaac64Rng = SeedableRng::from_seed(seed);
|
|
assert_eq!(ra.gen_ascii_str(100u), rb.gen_ascii_str(100u));
|
|
}
|
|
|
|
#[test]
|
|
fn test_rng_32_reseed() {
|
|
let s = OSRng::new().gen_vec::<u32>(256);
|
|
let mut r: IsaacRng = SeedableRng::from_seed(s.as_slice());
|
|
let string1 = r.gen_ascii_str(100);
|
|
|
|
r.reseed(s);
|
|
|
|
let string2 = r.gen_ascii_str(100);
|
|
assert_eq!(string1, string2);
|
|
}
|
|
#[test]
|
|
fn test_rng_64_reseed() {
|
|
let s = OSRng::new().gen_vec::<u64>(256);
|
|
let mut r: Isaac64Rng = SeedableRng::from_seed(s.as_slice());
|
|
let string1 = r.gen_ascii_str(100);
|
|
|
|
r.reseed(s);
|
|
|
|
let string2 = r.gen_ascii_str(100);
|
|
assert_eq!(string1, string2);
|
|
}
|
|
|
|
#[test]
|
|
fn test_rng_32_true_values() {
|
|
let seed = &[1, 23, 456, 7890, 12345];
|
|
let mut ra: IsaacRng = SeedableRng::from_seed(seed);
|
|
// Regression test that isaac is actually using the above vector
|
|
let v = vec::from_fn(10, |_| ra.next_u32());
|
|
assert_eq!(v,
|
|
~[2558573138, 873787463, 263499565, 2103644246, 3595684709,
|
|
4203127393, 264982119, 2765226902, 2737944514, 3900253796]);
|
|
|
|
let seed = &[12345, 67890, 54321, 9876];
|
|
let mut rb: IsaacRng = SeedableRng::from_seed(seed);
|
|
// skip forward to the 10000th number
|
|
for _ in range(0, 10000) { rb.next_u32(); }
|
|
|
|
let v = vec::from_fn(10, |_| rb.next_u32());
|
|
assert_eq!(v,
|
|
~[3676831399, 3183332890, 2834741178, 3854698763, 2717568474,
|
|
1576568959, 3507990155, 179069555, 141456972, 2478885421]);
|
|
}
|
|
#[test]
|
|
fn test_rng_64_true_values() {
|
|
let seed = &[1, 23, 456, 7890, 12345];
|
|
let mut ra: Isaac64Rng = SeedableRng::from_seed(seed);
|
|
// Regression test that isaac is actually using the above vector
|
|
let v = vec::from_fn(10, |_| ra.next_u64());
|
|
assert_eq!(v,
|
|
~[547121783600835980, 14377643087320773276, 17351601304698403469,
|
|
1238879483818134882, 11952566807690396487, 13970131091560099343,
|
|
4469761996653280935, 15552757044682284409, 6860251611068737823,
|
|
13722198873481261842]);
|
|
|
|
let seed = &[12345, 67890, 54321, 9876];
|
|
let mut rb: Isaac64Rng = SeedableRng::from_seed(seed);
|
|
// skip forward to the 10000th number
|
|
for _ in range(0, 10000) { rb.next_u64(); }
|
|
|
|
let v = vec::from_fn(10, |_| rb.next_u64());
|
|
assert_eq!(v,
|
|
~[18143823860592706164, 8491801882678285927, 2699425367717515619,
|
|
17196852593171130876, 2606123525235546165, 15790932315217671084,
|
|
596345674630742204, 9947027391921273664, 11788097613744130851,
|
|
10391409374914919106]);
|
|
}
|
|
}
|