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Diffstat (limited to 'vendor/rand/src/prng/isaac64.rs')
-rw-r--r-- | vendor/rand/src/prng/isaac64.rs | 340 |
1 files changed, 0 insertions, 340 deletions
diff --git a/vendor/rand/src/prng/isaac64.rs b/vendor/rand/src/prng/isaac64.rs deleted file mode 100644 index b98e3fe..0000000 --- a/vendor/rand/src/prng/isaac64.rs +++ /dev/null @@ -1,340 +0,0 @@ -// 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-64 random number generator. - -use core::slice; -use core::iter::repeat; -use core::num::Wrapping as w; -use core::fmt; - -use {Rng, SeedableRng, Rand}; - -#[allow(bad_style)] -type w64 = w<u64>; - -const RAND_SIZE_64_LEN: usize = 8; -const RAND_SIZE_64: usize = 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) -#[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 { - /// 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 $var = w(0x9e3779b97f4a7c13); - ) - } - init!(a); init!(b); init!(c); init!(d); - init!(e); init!(f); init!(g); init!(h); - - macro_rules! mix { - () => {{ - a=a-e; f=f^(h>>9); h=h+a; - b=b-f; g=g^(a<<9); a=a+b; - c=c-g; h=h^(b>>23); b=b+c; - d=d-h; a=a^(c<<15); c=c+d; - e=e-a; b=b^(d>>14); d=d+e; - f=f-b; c=c^(e<<20); e=e+f; - g=g-c; d=d^(f>>17); f=f+g; - h=h-d; e=e^(g<<14); g=g+h; - }} - } - - for _ in 0..4 { - mix!(); - } - - if use_rsl { - macro_rules! memloop { - ($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(); - } - - /// Refills the output buffer (`self.rsl`) - fn isaac64(&mut self) { - self.c = self.c + w(1); - // abbreviations - 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; - } -} - -// Cannot be derived because [u32; 256] does not implement Clone -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 { - // make some more numbers - self.isaac64(); - } - self.cnt -= 1; - - // See corresponding location in IsaacRng.next_u32 for - // explanation. - 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]) { - // 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(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); - } - - /// 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 - } -} - -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::Isaac64Rng; - - #[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_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_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_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 = (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); - // skip forward to the 10000th number - 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()); - } - } -} |