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1a4d82fc JJ |
1 | // Copyright 2013 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | //! The ISAAC random number generator. | |
12 | ||
c34b1796 AL |
13 | #![allow(non_camel_case_types)] |
14 | ||
1a4d82fc | 15 | use core::slice; |
c34b1796 AL |
16 | use core::iter::repeat; |
17 | use core::num::Wrapping as w; | |
1a4d82fc JJ |
18 | |
19 | use {Rng, SeedableRng, Rand}; | |
20 | ||
c34b1796 AL |
21 | type w32 = w<u32>; |
22 | type w64 = w<u64>; | |
23 | ||
24 | const RAND_SIZE_LEN: usize = 8; | |
25 | const RAND_SIZE: u32 = 1 << RAND_SIZE_LEN; | |
26 | const RAND_SIZE_USIZE: usize = 1 << RAND_SIZE_LEN; | |
1a4d82fc JJ |
27 | |
28 | /// A random number generator that uses the ISAAC algorithm[1]. | |
29 | /// | |
30 | /// The ISAAC algorithm is generally accepted as suitable for | |
31 | /// cryptographic purposes, but this implementation has not be | |
32 | /// verified as such. Prefer a generator like `OsRng` that defers to | |
33 | /// the operating system for cases that need high security. | |
34 | /// | |
35 | /// [1]: Bob Jenkins, [*ISAAC: A fast cryptographic random number | |
36 | /// generator*](http://www.burtleburtle.net/bob/rand/isaacafa.html) | |
37 | #[derive(Copy)] | |
38 | pub struct IsaacRng { | |
39 | cnt: u32, | |
c34b1796 AL |
40 | rsl: [w32; RAND_SIZE_USIZE], |
41 | mem: [w32; RAND_SIZE_USIZE], | |
42 | a: w32, | |
43 | b: w32, | |
44 | c: w32, | |
1a4d82fc JJ |
45 | } |
46 | ||
47 | static EMPTY: IsaacRng = IsaacRng { | |
48 | cnt: 0, | |
c34b1796 AL |
49 | rsl: [w(0); RAND_SIZE_USIZE], |
50 | mem: [w(0); RAND_SIZE_USIZE], | |
b039eaaf SL |
51 | a: w(0), |
52 | b: w(0), | |
53 | c: w(0), | |
1a4d82fc JJ |
54 | }; |
55 | ||
56 | impl IsaacRng { | |
1a4d82fc JJ |
57 | /// Create an ISAAC random number generator using the default |
58 | /// fixed seed. | |
59 | pub fn new_unseeded() -> IsaacRng { | |
60 | let mut rng = EMPTY; | |
61 | rng.init(false); | |
62 | rng | |
63 | } | |
64 | ||
65 | /// Initialises `self`. If `use_rsl` is true, then use the current value | |
66 | /// of `rsl` as a seed, otherwise construct one algorithmically (not | |
67 | /// randomly). | |
68 | fn init(&mut self, use_rsl: bool) { | |
c34b1796 | 69 | let mut a = w(0x9e3779b9); |
1a4d82fc JJ |
70 | let mut b = a; |
71 | let mut c = a; | |
72 | let mut d = a; | |
73 | let mut e = a; | |
74 | let mut f = a; | |
75 | let mut g = a; | |
76 | let mut h = a; | |
77 | ||
78 | macro_rules! mix { | |
79 | () => {{ | |
9cc50fc6 SL |
80 | a = a ^ (b << 11); |
81 | d = d + a; | |
82 | b = b + c; | |
83 | ||
84 | b = b ^ (c >> 2); | |
85 | e = e + b; | |
86 | c = c + d; | |
87 | ||
88 | c = c ^ (d << 8); | |
89 | f = f + c; | |
90 | d = d + e; | |
91 | ||
92 | d = d ^ (e >> 16); | |
93 | g = g + d; | |
94 | e = e + f; | |
95 | ||
96 | e = e ^ (f << 10); | |
97 | h = h + e; | |
98 | f = f + g; | |
99 | ||
100 | f = f ^ (g >> 4); | |
101 | a = a + f; | |
102 | g = g + h; | |
103 | ||
104 | g = g ^ (h << 8); | |
105 | b = b + g; | |
106 | h = h + a; | |
107 | ||
108 | h = h ^ (a >> 9); | |
109 | c = c + h; | |
110 | a = a + b; | |
1a4d82fc JJ |
111 | }} |
112 | } | |
113 | ||
85aaf69f | 114 | for _ in 0..4 { |
1a4d82fc JJ |
115 | mix!(); |
116 | } | |
117 | ||
118 | if use_rsl { | |
119 | macro_rules! memloop { | |
120 | ($arr:expr) => {{ | |
c34b1796 | 121 | for i in (0..RAND_SIZE_USIZE).step_by(8) { |
b039eaaf SL |
122 | a = a + $arr[i]; |
123 | b = b + $arr[i + 1]; | |
124 | c = c + $arr[i + 2]; | |
125 | d = d + $arr[i + 3]; | |
126 | e = e + $arr[i + 4]; | |
127 | f = f + $arr[i + 5]; | |
128 | g = g + $arr[i + 6]; | |
129 | h = h + $arr[i + 7]; | |
1a4d82fc | 130 | mix!(); |
b039eaaf SL |
131 | self.mem[i] = a; |
132 | self.mem[i + 1] = b; | |
133 | self.mem[i + 2] = c; | |
134 | self.mem[i + 3] = d; | |
135 | self.mem[i + 4] = e; | |
136 | self.mem[i + 5] = f; | |
137 | self.mem[i + 6] = g; | |
138 | self.mem[i + 7] = h; | |
1a4d82fc JJ |
139 | } |
140 | }} | |
141 | } | |
142 | ||
143 | memloop!(self.rsl); | |
144 | memloop!(self.mem); | |
145 | } else { | |
c34b1796 | 146 | for i in (0..RAND_SIZE_USIZE).step_by(8) { |
1a4d82fc | 147 | mix!(); |
b039eaaf SL |
148 | self.mem[i] = a; |
149 | self.mem[i + 1] = b; | |
150 | self.mem[i + 2] = c; | |
151 | self.mem[i + 3] = d; | |
152 | self.mem[i + 4] = e; | |
153 | self.mem[i + 5] = f; | |
154 | self.mem[i + 6] = g; | |
155 | self.mem[i + 7] = h; | |
1a4d82fc JJ |
156 | } |
157 | } | |
158 | ||
159 | self.isaac(); | |
160 | } | |
161 | ||
162 | /// Refills the output buffer (`self.rsl`) | |
163 | #[inline] | |
1a4d82fc | 164 | fn isaac(&mut self) { |
c34b1796 | 165 | self.c = self.c + w(1); |
1a4d82fc JJ |
166 | // abbreviations |
167 | let mut a = self.a; | |
168 | let mut b = self.b + self.c; | |
169 | ||
c34b1796 | 170 | const MIDPOINT: usize = RAND_SIZE_USIZE / 2; |
1a4d82fc JJ |
171 | |
172 | macro_rules! ind { | |
c34b1796 | 173 | ($x:expr) => (self.mem[($x >> 2).0 as usize & (RAND_SIZE_USIZE - 1)] ) |
1a4d82fc JJ |
174 | } |
175 | ||
176 | let r = [(0, MIDPOINT), (MIDPOINT, 0)]; | |
62682a34 | 177 | for &(mr_offset, m2_offset) in &r { |
1a4d82fc JJ |
178 | |
179 | macro_rules! rngstepp { | |
180 | ($j:expr, $shift:expr) => {{ | |
181 | let base = $j; | |
c34b1796 | 182 | let mix = a << $shift; |
1a4d82fc JJ |
183 | |
184 | let x = self.mem[base + mr_offset]; | |
185 | a = (a ^ mix) + self.mem[base + m2_offset]; | |
186 | let y = ind!(x) + a + b; | |
187 | self.mem[base + mr_offset] = y; | |
188 | ||
c34b1796 | 189 | b = ind!(y >> RAND_SIZE_LEN) + x; |
1a4d82fc JJ |
190 | self.rsl[base + mr_offset] = b; |
191 | }} | |
192 | } | |
193 | ||
194 | macro_rules! rngstepn { | |
195 | ($j:expr, $shift:expr) => {{ | |
196 | let base = $j; | |
c34b1796 | 197 | let mix = a >> $shift; |
1a4d82fc JJ |
198 | |
199 | let x = self.mem[base + mr_offset]; | |
200 | a = (a ^ mix) + self.mem[base + m2_offset]; | |
201 | let y = ind!(x) + a + b; | |
202 | self.mem[base + mr_offset] = y; | |
203 | ||
c34b1796 | 204 | b = ind!(y >> RAND_SIZE_LEN) + x; |
1a4d82fc JJ |
205 | self.rsl[base + mr_offset] = b; |
206 | }} | |
207 | } | |
208 | ||
c34b1796 | 209 | for i in (0..MIDPOINT).step_by(4) { |
1a4d82fc JJ |
210 | rngstepp!(i + 0, 13); |
211 | rngstepn!(i + 1, 6); | |
212 | rngstepp!(i + 2, 2); | |
213 | rngstepn!(i + 3, 16); | |
214 | } | |
215 | } | |
216 | ||
217 | self.a = a; | |
218 | self.b = b; | |
219 | self.cnt = RAND_SIZE; | |
220 | } | |
221 | } | |
222 | ||
223 | // Cannot be derived because [u32; 256] does not implement Clone | |
224 | impl Clone for IsaacRng { | |
225 | fn clone(&self) -> IsaacRng { | |
226 | *self | |
227 | } | |
228 | } | |
229 | ||
230 | impl Rng for IsaacRng { | |
231 | #[inline] | |
232 | fn next_u32(&mut self) -> u32 { | |
233 | if self.cnt == 0 { | |
234 | // make some more numbers | |
235 | self.isaac(); | |
236 | } | |
237 | self.cnt -= 1; | |
238 | ||
239 | // self.cnt is at most RAND_SIZE, but that is before the | |
240 | // subtraction above. We want to index without bounds | |
241 | // checking, but this could lead to incorrect code if someone | |
242 | // misrefactors, so we check, sometimes. | |
243 | // | |
244 | // (Changes here should be reflected in Isaac64Rng.next_u64.) | |
245 | debug_assert!(self.cnt < RAND_SIZE); | |
246 | ||
247 | // (the % is cheaply telling the optimiser that we're always | |
248 | // in bounds, without unsafe. NB. this is a power of two, so | |
249 | // it optimises to a bitwise mask). | |
c34b1796 | 250 | self.rsl[(self.cnt % RAND_SIZE) as usize].0 |
1a4d82fc JJ |
251 | } |
252 | } | |
253 | ||
254 | impl<'a> SeedableRng<&'a [u32]> for IsaacRng { | |
255 | fn reseed(&mut self, seed: &'a [u32]) { | |
256 | // make the seed into [seed[0], seed[1], ..., seed[seed.len() | |
257 | // - 1], 0, 0, ...], to fill rng.rsl. | |
c34b1796 | 258 | let seed_iter = seed.iter().cloned().chain(repeat(0)); |
1a4d82fc JJ |
259 | |
260 | for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) { | |
c34b1796 | 261 | *rsl_elem = w(seed_elem); |
1a4d82fc JJ |
262 | } |
263 | self.cnt = 0; | |
c34b1796 AL |
264 | self.a = w(0); |
265 | self.b = w(0); | |
266 | self.c = w(0); | |
1a4d82fc JJ |
267 | |
268 | self.init(true); | |
269 | } | |
270 | ||
271 | /// Create an ISAAC random number generator with a seed. This can | |
272 | /// be any length, although the maximum number of elements used is | |
273 | /// 256 and any more will be silently ignored. A generator | |
274 | /// constructed with a given seed will generate the same sequence | |
275 | /// of values as all other generators constructed with that seed. | |
276 | fn from_seed(seed: &'a [u32]) -> IsaacRng { | |
277 | let mut rng = EMPTY; | |
278 | rng.reseed(seed); | |
279 | rng | |
280 | } | |
281 | } | |
282 | ||
283 | impl Rand for IsaacRng { | |
284 | fn rand<R: Rng>(other: &mut R) -> IsaacRng { | |
285 | let mut ret = EMPTY; | |
286 | unsafe { | |
287 | let ptr = ret.rsl.as_mut_ptr() as *mut u8; | |
288 | ||
c34b1796 | 289 | let slice = slice::from_raw_parts_mut(ptr, RAND_SIZE_USIZE * 4); |
1a4d82fc JJ |
290 | other.fill_bytes(slice); |
291 | } | |
292 | ret.cnt = 0; | |
c34b1796 AL |
293 | ret.a = w(0); |
294 | ret.b = w(0); | |
295 | ret.c = w(0); | |
1a4d82fc JJ |
296 | |
297 | ret.init(true); | |
298 | return ret; | |
299 | } | |
300 | } | |
301 | ||
c34b1796 AL |
302 | const RAND_SIZE_64_LEN: usize = 8; |
303 | const RAND_SIZE_64: usize = 1 << RAND_SIZE_64_LEN; | |
1a4d82fc JJ |
304 | |
305 | /// A random number generator that uses ISAAC-64[1], the 64-bit | |
306 | /// variant of the ISAAC algorithm. | |
307 | /// | |
308 | /// The ISAAC algorithm is generally accepted as suitable for | |
309 | /// cryptographic purposes, but this implementation has not be | |
310 | /// verified as such. Prefer a generator like `OsRng` that defers to | |
311 | /// the operating system for cases that need high security. | |
312 | /// | |
313 | /// [1]: Bob Jenkins, [*ISAAC: A fast cryptographic random number | |
314 | /// generator*](http://www.burtleburtle.net/bob/rand/isaacafa.html) | |
315 | #[derive(Copy)] | |
316 | pub struct Isaac64Rng { | |
c34b1796 AL |
317 | cnt: usize, |
318 | rsl: [w64; RAND_SIZE_64], | |
319 | mem: [w64; RAND_SIZE_64], | |
320 | a: w64, | |
321 | b: w64, | |
322 | c: w64, | |
1a4d82fc JJ |
323 | } |
324 | ||
325 | static EMPTY_64: Isaac64Rng = Isaac64Rng { | |
326 | cnt: 0, | |
c34b1796 AL |
327 | rsl: [w(0); RAND_SIZE_64], |
328 | mem: [w(0); RAND_SIZE_64], | |
b039eaaf SL |
329 | a: w(0), |
330 | b: w(0), | |
331 | c: w(0), | |
1a4d82fc JJ |
332 | }; |
333 | ||
334 | impl Isaac64Rng { | |
335 | /// Create a 64-bit ISAAC random number generator using the | |
336 | /// default fixed seed. | |
337 | pub fn new_unseeded() -> Isaac64Rng { | |
338 | let mut rng = EMPTY_64; | |
339 | rng.init(false); | |
340 | rng | |
341 | } | |
342 | ||
343 | /// Initialises `self`. If `use_rsl` is true, then use the current value | |
344 | /// of `rsl` as a seed, otherwise construct one algorithmically (not | |
345 | /// randomly). | |
346 | fn init(&mut self, use_rsl: bool) { | |
347 | macro_rules! init { | |
348 | ($var:ident) => ( | |
c34b1796 | 349 | let mut $var = w(0x9e3779b97f4a7c13); |
1a4d82fc JJ |
350 | ) |
351 | } | |
b039eaaf SL |
352 | init!(a); |
353 | init!(b); | |
354 | init!(c); | |
355 | init!(d); | |
356 | init!(e); | |
357 | init!(f); | |
358 | init!(g); | |
359 | init!(h); | |
1a4d82fc JJ |
360 | |
361 | macro_rules! mix { | |
362 | () => {{ | |
9cc50fc6 SL |
363 | a = a - e; |
364 | f = f ^ (h >> 9); | |
365 | h = h + a; | |
366 | ||
367 | b = b - f; | |
368 | g = g ^ (a << 9); | |
369 | a = a + b; | |
370 | ||
371 | c = c - g; | |
372 | h = h ^ (b >> 23); | |
373 | b = b + c; | |
374 | ||
375 | d = d - h; | |
376 | a = a ^ (c << 15); | |
377 | c = c + d; | |
378 | ||
379 | e = e - a; | |
380 | b = b ^ (d >> 14); | |
381 | d = d + e; | |
382 | ||
383 | f = f - b; | |
384 | c = c ^ (e << 20); | |
385 | e = e + f; | |
386 | ||
387 | g = g - c; | |
388 | d = d ^ (f >> 17); | |
389 | f = f + g; | |
390 | ||
391 | h = h - d; | |
392 | e = e ^ (g << 14); | |
393 | g = g + h; | |
1a4d82fc JJ |
394 | }} |
395 | } | |
396 | ||
85aaf69f | 397 | for _ in 0..4 { |
1a4d82fc JJ |
398 | mix!(); |
399 | } | |
400 | ||
401 | if use_rsl { | |
402 | macro_rules! memloop { | |
403 | ($arr:expr) => {{ | |
85aaf69f | 404 | for i in (0..RAND_SIZE_64 / 8).map(|i| i * 8) { |
b039eaaf SL |
405 | a = a + $arr[i]; |
406 | b = b + $arr[i + 1]; | |
407 | c = c + $arr[i + 2]; | |
408 | d = d + $arr[i + 3]; | |
409 | e = e + $arr[i + 4]; | |
410 | f = f + $arr[i + 5]; | |
411 | g = g + $arr[i + 6]; | |
412 | h = h + $arr[i + 7]; | |
1a4d82fc | 413 | mix!(); |
b039eaaf SL |
414 | self.mem[i] = a; |
415 | self.mem[i + 1] = b; | |
416 | self.mem[i + 2] = c; | |
417 | self.mem[i + 3] = d; | |
418 | self.mem[i + 4] = e; | |
419 | self.mem[i + 5] = f; | |
420 | self.mem[i + 6] = g; | |
421 | self.mem[i + 7] = h; | |
1a4d82fc JJ |
422 | } |
423 | }} | |
424 | } | |
425 | ||
426 | memloop!(self.rsl); | |
427 | memloop!(self.mem); | |
428 | } else { | |
85aaf69f | 429 | for i in (0..RAND_SIZE_64 / 8).map(|i| i * 8) { |
1a4d82fc | 430 | mix!(); |
b039eaaf SL |
431 | self.mem[i] = a; |
432 | self.mem[i + 1] = b; | |
433 | self.mem[i + 2] = c; | |
434 | self.mem[i + 3] = d; | |
435 | self.mem[i + 4] = e; | |
436 | self.mem[i + 5] = f; | |
437 | self.mem[i + 6] = g; | |
438 | self.mem[i + 7] = h; | |
1a4d82fc JJ |
439 | } |
440 | } | |
441 | ||
442 | self.isaac64(); | |
443 | } | |
444 | ||
445 | /// Refills the output buffer (`self.rsl`) | |
446 | fn isaac64(&mut self) { | |
c34b1796 | 447 | self.c = self.c + w(1); |
1a4d82fc JJ |
448 | // abbreviations |
449 | let mut a = self.a; | |
450 | let mut b = self.b + self.c; | |
92a42be0 | 451 | const MIDPOINT: usize = RAND_SIZE_64 / 2; |
b039eaaf | 452 | const MP_VEC: [(usize, usize); 2] = [(0, MIDPOINT), (MIDPOINT, 0)]; |
1a4d82fc JJ |
453 | macro_rules! ind { |
454 | ($x:expr) => { | |
c34b1796 | 455 | *self.mem.get_unchecked((($x >> 3).0 as usize) & (RAND_SIZE_64 - 1)) |
1a4d82fc JJ |
456 | } |
457 | } | |
458 | ||
62682a34 | 459 | for &(mr_offset, m2_offset) in &MP_VEC { |
85aaf69f | 460 | for base in (0..MIDPOINT / 4).map(|i| i * 4) { |
1a4d82fc JJ |
461 | |
462 | macro_rules! rngstepp { | |
463 | ($j:expr, $shift:expr) => {{ | |
464 | let base = base + $j; | |
c34b1796 | 465 | let mix = a ^ (a << $shift); |
1a4d82fc JJ |
466 | let mix = if $j == 0 {!mix} else {mix}; |
467 | ||
468 | unsafe { | |
469 | let x = *self.mem.get_unchecked(base + mr_offset); | |
470 | a = mix + *self.mem.get_unchecked(base + m2_offset); | |
471 | let y = ind!(x) + a + b; | |
472 | *self.mem.get_unchecked_mut(base + mr_offset) = y; | |
473 | ||
474 | b = ind!(y >> RAND_SIZE_64_LEN) + x; | |
475 | *self.rsl.get_unchecked_mut(base + mr_offset) = b; | |
476 | } | |
477 | }} | |
478 | } | |
479 | ||
480 | macro_rules! rngstepn { | |
481 | ($j:expr, $shift:expr) => {{ | |
482 | let base = base + $j; | |
c34b1796 | 483 | let mix = a ^ (a >> $shift); |
1a4d82fc JJ |
484 | let mix = if $j == 0 {!mix} else {mix}; |
485 | ||
486 | unsafe { | |
487 | let x = *self.mem.get_unchecked(base + mr_offset); | |
488 | a = mix + *self.mem.get_unchecked(base + m2_offset); | |
489 | let y = ind!(x) + a + b; | |
490 | *self.mem.get_unchecked_mut(base + mr_offset) = y; | |
491 | ||
492 | b = ind!(y >> RAND_SIZE_64_LEN) + x; | |
493 | *self.rsl.get_unchecked_mut(base + mr_offset) = b; | |
494 | } | |
495 | }} | |
496 | } | |
497 | ||
85aaf69f SL |
498 | rngstepp!(0, 21); |
499 | rngstepn!(1, 5); | |
500 | rngstepp!(2, 12); | |
501 | rngstepn!(3, 33); | |
1a4d82fc JJ |
502 | } |
503 | } | |
504 | ||
505 | self.a = a; | |
506 | self.b = b; | |
507 | self.cnt = RAND_SIZE_64; | |
508 | } | |
509 | } | |
510 | ||
511 | // Cannot be derived because [u32; 256] does not implement Clone | |
512 | impl Clone for Isaac64Rng { | |
513 | fn clone(&self) -> Isaac64Rng { | |
514 | *self | |
515 | } | |
516 | } | |
517 | ||
518 | impl Rng for Isaac64Rng { | |
519 | // FIXME #7771: having next_u32 like this should be unnecessary | |
520 | #[inline] | |
521 | fn next_u32(&mut self) -> u32 { | |
522 | self.next_u64() as u32 | |
523 | } | |
524 | ||
525 | #[inline] | |
526 | fn next_u64(&mut self) -> u64 { | |
527 | if self.cnt == 0 { | |
528 | // make some more numbers | |
529 | self.isaac64(); | |
530 | } | |
531 | self.cnt -= 1; | |
532 | ||
533 | // See corresponding location in IsaacRng.next_u32 for | |
534 | // explanation. | |
535 | debug_assert!(self.cnt < RAND_SIZE_64); | |
c34b1796 | 536 | self.rsl[(self.cnt % RAND_SIZE_64) as usize].0 |
1a4d82fc JJ |
537 | } |
538 | } | |
539 | ||
540 | impl<'a> SeedableRng<&'a [u64]> for Isaac64Rng { | |
541 | fn reseed(&mut self, seed: &'a [u64]) { | |
542 | // make the seed into [seed[0], seed[1], ..., seed[seed.len() | |
543 | // - 1], 0, 0, ...], to fill rng.rsl. | |
c34b1796 | 544 | let seed_iter = seed.iter().cloned().chain(repeat(0)); |
1a4d82fc JJ |
545 | |
546 | for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) { | |
c34b1796 | 547 | *rsl_elem = w(seed_elem); |
1a4d82fc JJ |
548 | } |
549 | self.cnt = 0; | |
c34b1796 AL |
550 | self.a = w(0); |
551 | self.b = w(0); | |
552 | self.c = w(0); | |
1a4d82fc JJ |
553 | |
554 | self.init(true); | |
555 | } | |
556 | ||
557 | /// Create an ISAAC random number generator with a seed. This can | |
558 | /// be any length, although the maximum number of elements used is | |
559 | /// 256 and any more will be silently ignored. A generator | |
560 | /// constructed with a given seed will generate the same sequence | |
561 | /// of values as all other generators constructed with that seed. | |
562 | fn from_seed(seed: &'a [u64]) -> Isaac64Rng { | |
563 | let mut rng = EMPTY_64; | |
564 | rng.reseed(seed); | |
565 | rng | |
566 | } | |
567 | } | |
568 | ||
569 | impl Rand for Isaac64Rng { | |
570 | fn rand<R: Rng>(other: &mut R) -> Isaac64Rng { | |
571 | let mut ret = EMPTY_64; | |
572 | unsafe { | |
573 | let ptr = ret.rsl.as_mut_ptr() as *mut u8; | |
574 | ||
c34b1796 | 575 | let slice = slice::from_raw_parts_mut(ptr, RAND_SIZE_64 * 8); |
1a4d82fc JJ |
576 | other.fill_bytes(slice); |
577 | } | |
578 | ret.cnt = 0; | |
c34b1796 AL |
579 | ret.a = w(0); |
580 | ret.b = w(0); | |
581 | ret.c = w(0); | |
1a4d82fc JJ |
582 | |
583 | ret.init(true); | |
584 | return ret; | |
585 | } | |
586 | } | |
587 | ||
588 | ||
589 | #[cfg(test)] | |
d9579d0f | 590 | mod tests { |
1a4d82fc JJ |
591 | use std::prelude::v1::*; |
592 | ||
1a4d82fc JJ |
593 | use {Rng, SeedableRng}; |
594 | use super::{IsaacRng, Isaac64Rng}; | |
595 | ||
596 | #[test] | |
597 | fn test_rng_32_rand_seeded() { | |
598 | let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>(); | |
c34b1796 AL |
599 | let mut ra: IsaacRng = SeedableRng::from_seed(&s[..]); |
600 | let mut rb: IsaacRng = SeedableRng::from_seed(&s[..]); | |
9cc50fc6 SL |
601 | assert!(ra.gen_ascii_chars().take(100) |
602 | .eq(rb.gen_ascii_chars().take(100))); | |
1a4d82fc JJ |
603 | } |
604 | #[test] | |
605 | fn test_rng_64_rand_seeded() { | |
606 | let s = ::test::rng().gen_iter::<u64>().take(256).collect::<Vec<u64>>(); | |
c34b1796 AL |
607 | let mut ra: Isaac64Rng = SeedableRng::from_seed(&s[..]); |
608 | let mut rb: Isaac64Rng = SeedableRng::from_seed(&s[..]); | |
9cc50fc6 SL |
609 | assert!(ra.gen_ascii_chars().take(100) |
610 | .eq(rb.gen_ascii_chars().take(100))); | |
1a4d82fc JJ |
611 | } |
612 | ||
613 | #[test] | |
614 | fn test_rng_32_seeded() { | |
615 | let seed: &[_] = &[1, 23, 456, 7890, 12345]; | |
616 | let mut ra: IsaacRng = SeedableRng::from_seed(seed); | |
617 | let mut rb: IsaacRng = SeedableRng::from_seed(seed); | |
9cc50fc6 SL |
618 | assert!(ra.gen_ascii_chars().take(100) |
619 | .eq(rb.gen_ascii_chars().take(100))); | |
1a4d82fc JJ |
620 | } |
621 | #[test] | |
622 | fn test_rng_64_seeded() { | |
623 | let seed: &[_] = &[1, 23, 456, 7890, 12345]; | |
624 | let mut ra: Isaac64Rng = SeedableRng::from_seed(seed); | |
625 | let mut rb: Isaac64Rng = SeedableRng::from_seed(seed); | |
9cc50fc6 SL |
626 | assert!(ra.gen_ascii_chars().take(100) |
627 | .eq(rb.gen_ascii_chars().take(100))); | |
1a4d82fc JJ |
628 | } |
629 | ||
630 | #[test] | |
631 | fn test_rng_32_reseed() { | |
632 | let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>(); | |
c34b1796 | 633 | let mut r: IsaacRng = SeedableRng::from_seed(&s[..]); |
1a4d82fc JJ |
634 | let string1: String = r.gen_ascii_chars().take(100).collect(); |
635 | ||
85aaf69f | 636 | r.reseed(&s); |
1a4d82fc JJ |
637 | |
638 | let string2: String = r.gen_ascii_chars().take(100).collect(); | |
639 | assert_eq!(string1, string2); | |
640 | } | |
641 | #[test] | |
642 | fn test_rng_64_reseed() { | |
643 | let s = ::test::rng().gen_iter::<u64>().take(256).collect::<Vec<u64>>(); | |
c34b1796 | 644 | let mut r: Isaac64Rng = SeedableRng::from_seed(&s[..]); |
1a4d82fc JJ |
645 | let string1: String = r.gen_ascii_chars().take(100).collect(); |
646 | ||
85aaf69f | 647 | r.reseed(&s); |
1a4d82fc JJ |
648 | |
649 | let string2: String = r.gen_ascii_chars().take(100).collect(); | |
650 | assert_eq!(string1, string2); | |
651 | } | |
652 | ||
653 | #[test] | |
b039eaaf | 654 | #[rustfmt_skip] |
1a4d82fc JJ |
655 | fn test_rng_32_true_values() { |
656 | let seed: &[_] = &[1, 23, 456, 7890, 12345]; | |
657 | let mut ra: IsaacRng = SeedableRng::from_seed(seed); | |
658 | // Regression test that isaac is actually using the above vector | |
85aaf69f | 659 | let v = (0..10).map(|_| ra.next_u32()).collect::<Vec<_>>(); |
1a4d82fc JJ |
660 | assert_eq!(v, |
661 | vec!(2558573138, 873787463, 263499565, 2103644246, 3595684709, | |
662 | 4203127393, 264982119, 2765226902, 2737944514, 3900253796)); | |
663 | ||
664 | let seed: &[_] = &[12345, 67890, 54321, 9876]; | |
665 | let mut rb: IsaacRng = SeedableRng::from_seed(seed); | |
666 | // skip forward to the 10000th number | |
b039eaaf SL |
667 | for _ in 0..10000 { |
668 | rb.next_u32(); | |
669 | } | |
1a4d82fc | 670 | |
85aaf69f | 671 | let v = (0..10).map(|_| rb.next_u32()).collect::<Vec<_>>(); |
1a4d82fc JJ |
672 | assert_eq!(v, |
673 | vec!(3676831399, 3183332890, 2834741178, 3854698763, 2717568474, | |
674 | 1576568959, 3507990155, 179069555, 141456972, 2478885421)); | |
675 | } | |
676 | #[test] | |
b039eaaf | 677 | #[rustfmt_skip] |
1a4d82fc JJ |
678 | fn test_rng_64_true_values() { |
679 | let seed: &[_] = &[1, 23, 456, 7890, 12345]; | |
680 | let mut ra: Isaac64Rng = SeedableRng::from_seed(seed); | |
681 | // Regression test that isaac is actually using the above vector | |
85aaf69f | 682 | let v = (0..10).map(|_| ra.next_u64()).collect::<Vec<_>>(); |
1a4d82fc JJ |
683 | assert_eq!(v, |
684 | vec!(547121783600835980, 14377643087320773276, 17351601304698403469, | |
685 | 1238879483818134882, 11952566807690396487, 13970131091560099343, | |
686 | 4469761996653280935, 15552757044682284409, 6860251611068737823, | |
687 | 13722198873481261842)); | |
688 | ||
689 | let seed: &[_] = &[12345, 67890, 54321, 9876]; | |
690 | let mut rb: Isaac64Rng = SeedableRng::from_seed(seed); | |
691 | // skip forward to the 10000th number | |
b039eaaf SL |
692 | for _ in 0..10000 { |
693 | rb.next_u64(); | |
694 | } | |
1a4d82fc | 695 | |
85aaf69f | 696 | let v = (0..10).map(|_| rb.next_u64()).collect::<Vec<_>>(); |
1a4d82fc JJ |
697 | assert_eq!(v, |
698 | vec!(18143823860592706164, 8491801882678285927, 2699425367717515619, | |
699 | 17196852593171130876, 2606123525235546165, 15790932315217671084, | |
700 | 596345674630742204, 9947027391921273664, 11788097613744130851, | |
701 | 10391409374914919106)); | |
b039eaaf | 702 | |
1a4d82fc JJ |
703 | } |
704 | ||
705 | #[test] | |
706 | fn test_rng_clone() { | |
707 | let seed: &[_] = &[1, 23, 456, 7890, 12345]; | |
708 | let mut rng: Isaac64Rng = SeedableRng::from_seed(seed); | |
709 | let mut clone = rng.clone(); | |
85aaf69f | 710 | for _ in 0..16 { |
1a4d82fc JJ |
711 | assert_eq!(rng.next_u64(), clone.next_u64()); |
712 | } | |
713 | } | |
714 | } |