#![allow(non_camel_case_types)]
use std::slice;
use std::iter::repeat;
use std::num::Wrapping as w;
use std::fmt;
use {Rng, SeedableRng, Rand, w32, w64};
const RAND_SIZE_LEN: usize = 8;
const RAND_SIZE: u32 = 1 << RAND_SIZE_LEN;
const RAND_SIZE_USIZE: usize = 1 << RAND_SIZE_LEN;
#[derive(Copy)]
pub struct IsaacRng {
cnt: u32,
rsl: [w32; RAND_SIZE_USIZE],
mem: [w32; RAND_SIZE_USIZE],
a: w32,
b: w32,
c: w32,
}
static EMPTY: IsaacRng = IsaacRng {
cnt: 0,
rsl: [w(0); RAND_SIZE_USIZE],
mem: [w(0); RAND_SIZE_USIZE],
a: w(0), b: w(0), c: w(0),
};
impl IsaacRng {
pub fn new_unseeded() -> IsaacRng {
let mut rng = EMPTY;
rng.init(false);
rng
}
fn init(&mut self, use_rsl: bool) {
let mut a = w(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=a^(b<<11); d=d+a; b=b+c;
b=b^(c>>2); e=e+b; c=c+d;
c=c^(d<<8); f=f+c; d=d+e;
d=d^(e>>16); g=g+d; e=e+f;
e=e^(f<<10); h=h+e; f=f+g;
f=f^(g>>4); a=a+f; g=g+h;
g=g^(h<<8); b=b+g; h=h+a;
h=h^(a>>9); c=c+h; a=a+b;
}}
}
for _ in 0..4 {
mix!();
}
if use_rsl {
macro_rules! memloop {
($arr:expr) => {{
for i in (0..RAND_SIZE_USIZE/8).map(|i| i * 8) {
a=a+$arr[i ]; b=b+$arr[i+1];
c=c+$arr[i+2]; d=d+$arr[i+3];
e=e+$arr[i+4]; f=f+$arr[i+5];
g=g+$arr[i+6]; h=h+$arr[i+7];
mix!();
self.mem[i ]=a; self.mem[i+1]=b;
self.mem[i+2]=c; self.mem[i+3]=d;
self.mem[i+4]=e; self.mem[i+5]=f;
self.mem[i+6]=g; self.mem[i+7]=h;
}
}}
}
memloop!(self.rsl);
memloop!(self.mem);
} else {
for i in (0..RAND_SIZE_USIZE/8).map(|i| i * 8) {
mix!();
self.mem[i ]=a; self.mem[i+1]=b;
self.mem[i+2]=c; self.mem[i+3]=d;
self.mem[i+4]=e; self.mem[i+5]=f;
self.mem[i+6]=g; self.mem[i+7]=h;
}
}
self.isaac();
}
#[inline]
fn isaac(&mut self) {
self.c = self.c + w(1);
let mut a = self.a;
let mut b = self.b + self.c;
const MIDPOINT: usize = RAND_SIZE_USIZE / 2;
macro_rules! ind {
($x:expr) => ( self.mem[($x >> 2usize).0 as usize & (RAND_SIZE_USIZE - 1)] )
}
let r = [(0, MIDPOINT), (MIDPOINT, 0)];
for &(mr_offset, m2_offset) in r.iter() {
macro_rules! rngstepp {
($j:expr, $shift:expr) => {{
let base = $j;
let mix = a << $shift;
let x = self.mem[base + mr_offset];
a = (a ^ mix) + self.mem[base + m2_offset];
let y = ind!(x) + a + b;
self.mem[base + mr_offset] = y;
b = ind!(y >> RAND_SIZE_LEN) + x;
self.rsl[base + mr_offset] = b;
}}
}
macro_rules! rngstepn {
($j:expr, $shift:expr) => {{
let base = $j;
let mix = a >> $shift;
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;
}}
}
for i in (0..MIDPOINT/4).map(|i| i * 4) {
rngstepp!(i + 0, 13);
rngstepn!(i + 1, 6);
rngstepp!(i + 2, 2);
rngstepn!(i + 3, 16);
}
}
self.a = a;
self.b = b;
self.cnt = RAND_SIZE;
}
}
impl Clone for IsaacRng {
fn clone(&self) -> IsaacRng {
*self
}
}
impl Rng for IsaacRng {
#[inline]
fn next_u32(&mut self) -> u32 {
if self.cnt == 0 {
self.isaac();
}
self.cnt -= 1;
debug_assert!(self.cnt < RAND_SIZE);
self.rsl[(self.cnt % RAND_SIZE) as usize].0
}
}
impl<'a> SeedableRng<&'a [u32]> for IsaacRng {
fn reseed(&mut self, seed: &'a [u32]) {
let seed_iter = seed.iter().map(|&x| x).chain(repeat(0u32));
for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) {
*rsl_elem = w(seed_elem);
}
self.cnt = 0;
self.a = w(0);
self.b = w(0);
self.c = w(0);
self.init(true);
}
fn from_seed(seed: &'a [u32]) -> IsaacRng {
let mut rng = EMPTY;
rng.reseed(seed);
rng
}
}
impl Rand for IsaacRng {
fn rand<R: Rng>(other: &mut R) -> IsaacRng {
let mut ret = EMPTY;
unsafe {
let ptr = ret.rsl.as_mut_ptr() as *mut u8;
let slice = slice::from_raw_parts_mut(ptr, RAND_SIZE_USIZE * 4);
other.fill_bytes(slice);
}
ret.cnt = 0;
ret.a = w(0);
ret.b = w(0);
ret.c = w(0);
ret.init(true);
return ret;
}
}
impl fmt::Debug for IsaacRng {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "IsaacRng {{}}")
}
}
const RAND_SIZE_64_LEN: usize = 8;
const RAND_SIZE_64: usize = 1 << RAND_SIZE_64_LEN;
#[derive(Copy)]
pub struct Isaac64Rng {
cnt: usize,
rsl: [w64; RAND_SIZE_64],
mem: [w64; RAND_SIZE_64],
a: w64,
b: w64,
c: w64,
}
static EMPTY_64: Isaac64Rng = Isaac64Rng {
cnt: 0,
rsl: [w(0); RAND_SIZE_64],
mem: [w(0); RAND_SIZE_64],
a: w(0), b: w(0), c: w(0),
};
impl Isaac64Rng {
pub fn new_unseeded() -> Isaac64Rng {
let mut rng = EMPTY_64;
rng.init(false);
rng
}
fn init(&mut self, use_rsl: bool) {
macro_rules! init {
($var:ident) => (
let mut $var = w(0x9e3779b97f4a7c13);
)
}
init!(a); init!(b); init!(c); init!(d);
init!(e); init!(f); init!(g); init!(h);
macro_rules! mix {
() => {{
a=a-e; f=f^(h>>9); h=h+a;
b=b-f; g=g^(a<<9); a=a+b;
c=c-g; h=h^(b>>23); b=b+c;
d=d-h; a=a^(c<<15); c=c+d;
e=e-a; b=b^(d>>14); d=d+e;
f=f-b; c=c^(e<<20); e=e+f;
g=g-c; d=d^(f>>17); f=f+g;
h=h-d; e=e^(g<<14); g=g+h;
}}
}
for _ in 0..4 {
mix!();
}
if use_rsl {
macro_rules! memloop {
($arr:expr) => {{
for i in (0..RAND_SIZE_64 / 8).map(|i| i * 8) {
a=a+$arr[i ]; b=b+$arr[i+1];
c=c+$arr[i+2]; d=d+$arr[i+3];
e=e+$arr[i+4]; f=f+$arr[i+5];
g=g+$arr[i+6]; h=h+$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 (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();
}
fn isaac64(&mut self) {
self.c = self.c + w(1);
let mut a = self.a;
let mut b = self.b + self.c;
const MIDPOINT: usize = RAND_SIZE_64 / 2;
const MP_VEC: [(usize, usize); 2] = [(0,MIDPOINT), (MIDPOINT, 0)];
macro_rules! ind {
($x:expr) => {
*self.mem.get_unchecked((($x >> 3usize).0 as usize) & (RAND_SIZE_64 - 1))
}
}
for &(mr_offset, m2_offset) in MP_VEC.iter() {
for base in (0..MIDPOINT / 4).map(|i| i * 4) {
macro_rules! rngstepp {
($j:expr, $shift:expr) => {{
let base = base + $j;
let mix = a ^ (a << $shift);
let mix = if $j == 0 {!mix} else {mix};
unsafe {
let x = *self.mem.get_unchecked(base + mr_offset);
a = mix + *self.mem.get_unchecked(base + m2_offset);
let y = ind!(x) + a + b;
*self.mem.get_unchecked_mut(base + mr_offset) = y;
b = ind!(y >> RAND_SIZE_64_LEN) + x;
*self.rsl.get_unchecked_mut(base + mr_offset) = b;
}
}}
}
macro_rules! rngstepn {
($j:expr, $shift:expr) => {{
let base = base + $j;
let mix = a ^ (a >> $shift);
let mix = if $j == 0 {!mix} else {mix};
unsafe {
let x = *self.mem.get_unchecked(base + mr_offset);
a = mix + *self.mem.get_unchecked(base + m2_offset);
let y = ind!(x) + a + b;
*self.mem.get_unchecked_mut(base + mr_offset) = y;
b = ind!(y >> RAND_SIZE_64_LEN) + x;
*self.rsl.get_unchecked_mut(base + mr_offset) = b;
}
}}
}
rngstepp!(0, 21);
rngstepn!(1, 5);
rngstepp!(2, 12);
rngstepn!(3, 33);
}
}
self.a = a;
self.b = b;
self.cnt = RAND_SIZE_64;
}
}
impl Clone for Isaac64Rng {
fn clone(&self) -> Isaac64Rng {
*self
}
}
impl Rng for Isaac64Rng {
#[inline]
fn next_u32(&mut self) -> u32 {
self.next_u64() as u32
}
#[inline]
fn next_u64(&mut self) -> u64 {
if self.cnt == 0 {
self.isaac64();
}
self.cnt -= 1;
debug_assert!(self.cnt < RAND_SIZE_64);
self.rsl[(self.cnt % RAND_SIZE_64) as usize].0
}
}
impl<'a> SeedableRng<&'a [u64]> for Isaac64Rng {
fn reseed(&mut self, seed: &'a [u64]) {
let seed_iter = seed.iter().map(|&x| x).chain(repeat(0u64));
for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) {
*rsl_elem = w(seed_elem);
}
self.cnt = 0;
self.a = w(0);
self.b = w(0);
self.c = w(0);
self.init(true);
}
fn from_seed(seed: &'a [u64]) -> Isaac64Rng {
let mut rng = EMPTY_64;
rng.reseed(seed);
rng
}
}
impl Rand for Isaac64Rng {
fn rand<R: Rng>(other: &mut R) -> Isaac64Rng {
let mut ret = EMPTY_64;
unsafe {
let ptr = ret.rsl.as_mut_ptr() as *mut u8;
let slice = slice::from_raw_parts_mut(ptr, RAND_SIZE_64 * 8);
other.fill_bytes(slice);
}
ret.cnt = 0;
ret.a = w(0);
ret.b = w(0);
ret.c = w(0);
ret.init(true);
return ret;
}
}
impl fmt::Debug for Isaac64Rng {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "Isaac64Rng {{}}")
}
}
#[cfg(test)]
mod test {
use {Rng, SeedableRng};
use super::{IsaacRng, Isaac64Rng};
#[test]
fn test_rng_32_rand_seeded() {
let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>();
let mut ra: IsaacRng = SeedableRng::from_seed(&s[..]);
let mut rb: IsaacRng = SeedableRng::from_seed(&s[..]);
assert!(::test::iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
#[test]
fn test_rng_64_rand_seeded() {
let s = ::test::rng().gen_iter::<u64>().take(256).collect::<Vec<u64>>();
let mut ra: Isaac64Rng = SeedableRng::from_seed(&s[..]);
let mut rb: Isaac64Rng = SeedableRng::from_seed(&s[..]);
assert!(::test::iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
#[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!(::test::iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
#[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!(::test::iter_eq(ra.gen_ascii_chars().take(100),
rb.gen_ascii_chars().take(100)));
}
#[test]
fn test_rng_32_reseed() {
let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>();
let mut r: IsaacRng = SeedableRng::from_seed(&s[..]);
let string1: String = r.gen_ascii_chars().take(100).collect();
r.reseed(&s[..]);
let string2: String = r.gen_ascii_chars().take(100).collect();
assert_eq!(string1, string2);
}
#[test]
fn test_rng_64_reseed() {
let s = ::test::rng().gen_iter::<u64>().take(256).collect::<Vec<u64>>();
let mut r: Isaac64Rng = SeedableRng::from_seed(&s[..]);
let string1: String = r.gen_ascii_chars().take(100).collect();
r.reseed(&s[..]);
let string2: String = r.gen_ascii_chars().take(100).collect();
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);
let v = (0..10).map(|_| ra.next_u32()).collect::<Vec<_>>();
assert_eq!(v,
vec!(2558573138, 873787463, 263499565, 2103644246, 3595684709,
4203127393, 264982119, 2765226902, 2737944514, 3900253796));
let seed: &[_] = &[12345, 67890, 54321, 9876];
let mut rb: IsaacRng = SeedableRng::from_seed(seed);
for _ in 0..10000 { rb.next_u32(); }
let v = (0..10).map(|_| rb.next_u32()).collect::<Vec<_>>();
assert_eq!(v,
vec!(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);
let v = (0..10).map(|_| ra.next_u64()).collect::<Vec<_>>();
assert_eq!(v,
vec!(547121783600835980, 14377643087320773276, 17351601304698403469,
1238879483818134882, 11952566807690396487, 13970131091560099343,
4469761996653280935, 15552757044682284409, 6860251611068737823,
13722198873481261842));
let seed: &[_] = &[12345, 67890, 54321, 9876];
let mut rb: Isaac64Rng = SeedableRng::from_seed(seed);
for _ in 0..10000 { rb.next_u64(); }
let v = (0..10).map(|_| rb.next_u64()).collect::<Vec<_>>();
assert_eq!(v,
vec!(18143823860592706164, 8491801882678285927, 2699425367717515619,
17196852593171130876, 2606123525235546165, 15790932315217671084,
596345674630742204, 9947027391921273664, 11788097613744130851,
10391409374914919106));
}
#[test]
fn test_rng_clone() {
let seed: &[_] = &[1, 23, 456, 7890, 12345];
let mut rng: Isaac64Rng = SeedableRng::from_seed(seed);
let mut clone = rng.clone();
for _ in 0..16 {
assert_eq!(rng.next_u64(), clone.next_u64());
}
}
}