-
Notifications
You must be signed in to change notification settings - Fork 5.3k
/
random.c
1396 lines (1254 loc) · 33.9 KB
/
random.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**********************************************************************
random.c -
$Author$
created at: Fri Dec 24 16:39:21 JST 1993
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
/*
This is based on trimmed version of MT19937. To get the original version,
contact <http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html>.
The original copyright notice follows.
A C-program for MT19937, with initialization improved 2002/2/10.
Coded by Takuji Nishimura and Makoto Matsumoto.
This is a faster version by taking Shawn Cokus's optimization,
Matthe Bellew's simplification, Isaku Wada's real version.
Before using, initialize the state by using init_genrand(mt, seed)
or init_by_array(mt, init_key, key_length).
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Any feedback is very welcome.
http://www.math.keio.ac.jp/matumoto/emt.html
email: matumoto@math.keio.ac.jp
*/
#include "ruby/ruby.h"
#include <limits.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <math.h>
#include <errno.h>
#if defined(HAVE_SYS_TIME_H)
#include <sys/time.h>
#endif
#ifdef _WIN32
# if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0400
# undef _WIN32_WINNT
# define _WIN32_WINNT 0x400
# undef __WINCRYPT_H__
# endif
#include <wincrypt.h>
#endif
typedef int int_must_be_32bit_at_least[sizeof(int) * CHAR_BIT < 32 ? -1 : 1];
/* Period parameters */
#define N 624
#define M 397
#define MATRIX_A 0x9908b0dfU /* constant vector a */
#define UMASK 0x80000000U /* most significant w-r bits */
#define LMASK 0x7fffffffU /* least significant r bits */
#define MIXBITS(u,v) ( ((u) & UMASK) | ((v) & LMASK) )
#define TWIST(u,v) ((MIXBITS((u),(v)) >> 1) ^ ((v)&1U ? MATRIX_A : 0U))
enum {MT_MAX_STATE = N};
struct MT {
/* assume int is enough to store 32bits */
unsigned int state[N]; /* the array for the state vector */
unsigned int *next;
int left;
};
#define genrand_initialized(mt) ((mt)->next != 0)
#define uninit_genrand(mt) ((mt)->next = 0)
/* initializes state[N] with a seed */
static void
init_genrand(struct MT *mt, unsigned int s)
{
int j;
mt->state[0] = s & 0xffffffffU;
for (j=1; j<N; j++) {
mt->state[j] = (1812433253U * (mt->state[j-1] ^ (mt->state[j-1] >> 30)) + j);
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
/* In the previous versions, MSBs of the seed affect */
/* only MSBs of the array state[]. */
/* 2002/01/09 modified by Makoto Matsumoto */
mt->state[j] &= 0xffffffff; /* for >32 bit machines */
}
mt->left = 1;
mt->next = mt->state + N;
}
/* initialize by an array with array-length */
/* init_key is the array for initializing keys */
/* key_length is its length */
/* slight change for C++, 2004/2/26 */
static void
init_by_array(struct MT *mt, unsigned int init_key[], int key_length)
{
int i, j, k;
init_genrand(mt, 19650218U);
i=1; j=0;
k = (N>key_length ? N : key_length);
for (; k; k--) {
mt->state[i] = (mt->state[i] ^ ((mt->state[i-1] ^ (mt->state[i-1] >> 30)) * 1664525U))
+ init_key[j] + j; /* non linear */
mt->state[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
i++; j++;
if (i>=N) { mt->state[0] = mt->state[N-1]; i=1; }
if (j>=key_length) j=0;
}
for (k=N-1; k; k--) {
mt->state[i] = (mt->state[i] ^ ((mt->state[i-1] ^ (mt->state[i-1] >> 30)) * 1566083941U))
- i; /* non linear */
mt->state[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
i++;
if (i>=N) { mt->state[0] = mt->state[N-1]; i=1; }
}
mt->state[0] = 0x80000000U; /* MSB is 1; assuring non-zero initial array */
}
static void
next_state(struct MT *mt)
{
unsigned int *p = mt->state;
int j;
mt->left = N;
mt->next = mt->state;
for (j=N-M+1; --j; p++)
*p = p[M] ^ TWIST(p[0], p[1]);
for (j=M; --j; p++)
*p = p[M-N] ^ TWIST(p[0], p[1]);
*p = p[M-N] ^ TWIST(p[0], mt->state[0]);
}
/* generates a random number on [0,0xffffffff]-interval */
static unsigned int
genrand_int32(struct MT *mt)
{
/* mt must be initialized */
unsigned int y;
if (--mt->left <= 0) next_state(mt);
y = *mt->next++;
/* Tempering */
y ^= (y >> 11);
y ^= (y << 7) & 0x9d2c5680;
y ^= (y << 15) & 0xefc60000;
y ^= (y >> 18);
return y;
}
/* generates a random number on [0,1) with 53-bit resolution*/
static double
genrand_real(struct MT *mt)
{
/* mt must be initialized */
unsigned int a = genrand_int32(mt)>>5, b = genrand_int32(mt)>>6;
return(a*67108864.0+b)*(1.0/9007199254740992.0);
}
/* generates a random number on [0,1] with 53-bit resolution*/
static double int_pair_to_real_inclusive(unsigned int a, unsigned int b);
static double
genrand_real2(struct MT *mt)
{
/* mt must be initialized */
unsigned int a = genrand_int32(mt), b = genrand_int32(mt);
return int_pair_to_real_inclusive(a, b);
}
/* These real versions are due to Isaku Wada, 2002/01/09 added */
#undef N
#undef M
/* These real versions are due to Isaku Wada, 2002/01/09 added */
typedef struct {
VALUE seed;
struct MT mt;
} rb_random_t;
#define DEFAULT_SEED_CNT 4
static rb_random_t default_rand;
static VALUE rand_init(struct MT *mt, VALUE vseed);
static VALUE random_seed(void);
static rb_random_t *
rand_start(rb_random_t *r)
{
struct MT *mt = &r->mt;
if (!genrand_initialized(mt)) {
r->seed = rand_init(mt, random_seed());
}
return r;
}
static struct MT *
default_mt(void)
{
return &rand_start(&default_rand)->mt;
}
unsigned int
rb_genrand_int32(void)
{
struct MT *mt = default_mt();
return genrand_int32(mt);
}
double
rb_genrand_real(void)
{
struct MT *mt = default_mt();
return genrand_real(mt);
}
#define BDIGITS(x) (RBIGNUM_DIGITS(x))
#define BITSPERDIG (SIZEOF_BDIGITS*CHAR_BIT)
#define BIGRAD ((BDIGIT_DBL)1 << BITSPERDIG)
#define DIGSPERINT (SIZEOF_INT/SIZEOF_BDIGITS)
#define BIGUP(x) ((BDIGIT_DBL)(x) << BITSPERDIG)
#define BIGDN(x) RSHIFT((x),BITSPERDIG)
#define BIGLO(x) ((BDIGIT)((x) & (BIGRAD-1)))
#define BDIGMAX ((BDIGIT)-1)
#define roomof(n, m) (int)(((n)+(m)-1) / (m))
#define numberof(array) (int)(sizeof(array) / sizeof((array)[0]))
#define SIZEOF_INT32 (31/CHAR_BIT + 1)
static double
int_pair_to_real_inclusive(unsigned int a, unsigned int b)
{
VALUE x = rb_big_new(roomof(64, BITSPERDIG), 1);
VALUE m = rb_big_new(roomof(53, BITSPERDIG), 1);
BDIGIT *xd = BDIGITS(x);
int i = 0;
double r;
xd[i++] = (BDIGIT)b;
#if BITSPERDIG < 32
xd[i++] = (BDIGIT)(b >> BITSPERDIG);
#endif
xd[i++] = (BDIGIT)a;
#if BITSPERDIG < 32
xd[i++] = (BDIGIT)(a >> BITSPERDIG);
#endif
xd = BDIGITS(m);
#if BITSPERDIG < 53
MEMZERO(xd, BDIGIT, roomof(53, BITSPERDIG) - 1);
#endif
xd[53 / BITSPERDIG] = 1 << 53 % BITSPERDIG;
xd[0] |= 1;
x = rb_big_mul(x, m);
if (FIXNUM_P(x)) {
#if CHAR_BIT * SIZEOF_LONG > 64
r = (double)(FIX2ULONG(x) >> 64);
#else
return 0.0;
#endif
}
else {
#if 64 % BITSPERDIG == 0
long len = RBIGNUM_LEN(x);
xd = BDIGITS(x);
MEMMOVE(xd, xd + 64 / BITSPERDIG, BDIGIT, len - 64 / BITSPERDIG);
MEMZERO(xd + len - 64 / BITSPERDIG, BDIGIT, 64 / BITSPERDIG);
r = rb_big2dbl(x);
#else
x = rb_big_rshift(x, INT2FIX(64));
if (FIXNUM_P(x)) {
r = (double)FIX2ULONG(x);
}
else {
r = rb_big2dbl(x);
}
#endif
}
return ldexp(r, -53);
}
VALUE rb_cRandom;
static VALUE rb_Random_DEFAULT;
#define id_minus '-'
#define id_plus '+'
static ID id_rand, id_bytes;
/* :nodoc: */
static void
random_mark(void *ptr)
{
rb_gc_mark(((rb_random_t *)ptr)->seed);
}
static void
random_free(void *ptr)
{
if (ptr != &default_rand)
xfree(ptr);
}
static size_t
random_memsize(const void *ptr)
{
return ptr ? sizeof(rb_random_t) : 0;
}
static const rb_data_type_t random_data_type = {
"random",
{
random_mark,
random_free,
random_memsize,
},
};
static rb_random_t *
get_rnd(VALUE obj)
{
rb_random_t *ptr;
TypedData_Get_Struct(obj, rb_random_t, &random_data_type, ptr);
return ptr;
}
static rb_random_t *
try_get_rnd(VALUE obj)
{
if (obj == rb_cRandom) {
return rand_start(&default_rand);
}
if (!rb_typeddata_is_kind_of(obj, &random_data_type)) return NULL;
return DATA_PTR(obj);
}
/* :nodoc: */
static VALUE
random_alloc(VALUE klass)
{
rb_random_t *rnd;
VALUE obj = TypedData_Make_Struct(klass, rb_random_t, &random_data_type, rnd);
rnd->seed = INT2FIX(0);
return obj;
}
static VALUE
rand_init(struct MT *mt, VALUE vseed)
{
volatile VALUE seed;
long blen = 0;
long fixnum_seed;
int i, j, len;
unsigned int buf0[SIZEOF_LONG / SIZEOF_INT32 * 4], *buf = buf0;
seed = rb_to_int(vseed);
switch (TYPE(seed)) {
case T_FIXNUM:
len = 1;
fixnum_seed = FIX2LONG(seed);
if (fixnum_seed < 0)
fixnum_seed = -fixnum_seed;
buf[0] = (unsigned int)(fixnum_seed & 0xffffffff);
#if SIZEOF_LONG > SIZEOF_INT32
if ((long)(int32_t)fixnum_seed != fixnum_seed) {
if ((buf[1] = (unsigned int)(fixnum_seed >> 32)) != 0) ++len;
}
#endif
break;
case T_BIGNUM:
blen = RBIGNUM_LEN(seed);
if (blen == 0) {
len = 1;
}
else {
if (blen > MT_MAX_STATE * SIZEOF_INT32 / SIZEOF_BDIGITS)
blen = MT_MAX_STATE * SIZEOF_INT32 / SIZEOF_BDIGITS;
len = roomof((int)blen * SIZEOF_BDIGITS, SIZEOF_INT32);
}
/* allocate ints for init_by_array */
if (len > numberof(buf0)) buf = ALLOC_N(unsigned int, len);
memset(buf, 0, len * sizeof(*buf));
len = 0;
for (i = (int)(blen-1); 0 <= i; i--) {
j = i * SIZEOF_BDIGITS / SIZEOF_INT32;
#if SIZEOF_BDIGITS < SIZEOF_INT32
buf[j] <<= BITSPERDIG;
#endif
buf[j] |= RBIGNUM_DIGITS(seed)[i];
if (!len && buf[j]) len = j;
}
++len;
break;
default:
rb_raise(rb_eTypeError, "failed to convert %s into Integer",
rb_obj_classname(vseed));
}
if (len <= 1) {
init_genrand(mt, buf[0]);
}
else {
if (buf[len-1] == 1) /* remove leading-zero-guard */
len--;
init_by_array(mt, buf, len);
}
if (buf != buf0) xfree(buf);
return seed;
}
/*
* call-seq: Random.new([seed]) -> prng
*
* Creates new Mersenne Twister based pseudorandom number generator with
* seed. When the argument seed is omitted, the generator is initialized
* with Random.new_seed.
*
* The argument seed is used to ensure repeatable sequences of random numbers
* between different runs of the program.
*
* prng = Random.new(1234)
* [ prng.rand, prng.rand ] #=> [0.191519450378892, 0.622108771039832]
* [ prng.integer(10), prng.integer(1000) ] #=> [4, 664]
* prng = Random.new(1234)
* [ prng.rand, prng.rand ] #=> [0.191519450378892, 0.622108771039832]
*/
static VALUE
random_init(int argc, VALUE *argv, VALUE obj)
{
VALUE vseed;
rb_random_t *rnd = get_rnd(obj);
if (argc == 0) {
vseed = random_seed();
}
else {
rb_scan_args(argc, argv, "01", &vseed);
}
rnd->seed = rand_init(&rnd->mt, vseed);
return obj;
}
#define DEFAULT_SEED_LEN (DEFAULT_SEED_CNT * (int)sizeof(int))
#if defined(S_ISCHR) && !defined(DOSISH)
# define USE_DEV_URANDOM 1
#else
# define USE_DEV_URANDOM 0
#endif
static void
fill_random_seed(unsigned int seed[DEFAULT_SEED_CNT])
{
static int n = 0;
struct timeval tv;
#if USE_DEV_URANDOM
int fd;
struct stat statbuf;
#elif defined(_WIN32)
HCRYPTPROV prov;
#endif
memset(seed, 0, DEFAULT_SEED_LEN);
#if USE_DEV_URANDOM
if ((fd = open("/dev/urandom", O_RDONLY
#ifdef O_NONBLOCK
|O_NONBLOCK
#endif
#ifdef O_NOCTTY
|O_NOCTTY
#endif
)) >= 0) {
rb_update_max_fd(fd);
if (fstat(fd, &statbuf) == 0 && S_ISCHR(statbuf.st_mode)) {
if (read(fd, seed, DEFAULT_SEED_LEN) < DEFAULT_SEED_LEN) {
/* abandon */;
}
}
close(fd);
}
#elif defined(_WIN32)
if (CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
CryptGenRandom(prov, DEFAULT_SEED_LEN, (void *)seed);
CryptReleaseContext(prov, 0);
}
#endif
gettimeofday(&tv, 0);
seed[0] ^= tv.tv_usec;
seed[1] ^= (unsigned int)tv.tv_sec;
#if SIZEOF_TIME_T > SIZEOF_INT
seed[0] ^= (unsigned int)((time_t)tv.tv_sec >> SIZEOF_INT * CHAR_BIT);
#endif
seed[2] ^= getpid() ^ (n++ << 16);
seed[3] ^= (unsigned int)(VALUE)&seed;
#if SIZEOF_VOIDP > SIZEOF_INT
seed[2] ^= (unsigned int)((VALUE)&seed >> SIZEOF_INT * CHAR_BIT);
#endif
}
static VALUE
make_seed_value(const void *ptr)
{
const long len = DEFAULT_SEED_LEN/SIZEOF_BDIGITS;
BDIGIT *digits;
NEWOBJ(big, struct RBignum);
OBJSETUP(big, rb_cBignum, T_BIGNUM);
RBIGNUM_SET_SIGN(big, 1);
rb_big_resize((VALUE)big, len + 1);
digits = RBIGNUM_DIGITS(big);
MEMCPY(digits, ptr, char, DEFAULT_SEED_LEN);
/* set leading-zero-guard if need. */
digits[len] =
#if SIZEOF_INT32 / SIZEOF_BDIGITS > 1
digits[len-2] <= 1 && digits[len-1] == 0
#else
digits[len-1] <= 1
#endif
? 1 : 0;
return rb_big_norm((VALUE)big);
}
/*
* call-seq: Random.new_seed -> integer
*
* Returns arbitrary value for seed.
*/
static VALUE
random_seed(void)
{
unsigned int buf[DEFAULT_SEED_CNT];
fill_random_seed(buf);
return make_seed_value(buf);
}
/*
* call-seq: prng.seed -> integer
*
* Returns the seed of the generator.
*/
static VALUE
random_get_seed(VALUE obj)
{
return get_rnd(obj)->seed;
}
/* :nodoc: */
static VALUE
random_copy(VALUE obj, VALUE orig)
{
rb_random_t *rnd1 = get_rnd(obj);
rb_random_t *rnd2 = get_rnd(orig);
struct MT *mt = &rnd1->mt;
*rnd1 = *rnd2;
mt->next = mt->state + numberof(mt->state) - mt->left + 1;
return obj;
}
static VALUE
mt_state(const struct MT *mt)
{
VALUE bigo = rb_big_new(sizeof(mt->state) / sizeof(BDIGIT), 1);
BDIGIT *d = RBIGNUM_DIGITS(bigo);
int i;
for (i = 0; i < numberof(mt->state); ++i) {
unsigned int x = mt->state[i];
#if SIZEOF_BDIGITS < SIZEOF_INT32
int j;
for (j = 0; j < SIZEOF_INT32 / SIZEOF_BDIGITS; ++j) {
*d++ = BIGLO(x);
x = BIGDN(x);
}
#else
*d++ = (BDIGIT)x;
#endif
}
return rb_big_norm(bigo);
}
/* :nodoc: */
static VALUE
random_state(VALUE obj)
{
rb_random_t *rnd = get_rnd(obj);
return mt_state(&rnd->mt);
}
/* :nodoc: */
static VALUE
random_s_state(VALUE klass)
{
return mt_state(&default_rand.mt);
}
/* :nodoc: */
static VALUE
random_left(VALUE obj)
{
rb_random_t *rnd = get_rnd(obj);
return INT2FIX(rnd->mt.left);
}
/* :nodoc: */
static VALUE
random_s_left(VALUE klass)
{
return INT2FIX(default_rand.mt.left);
}
/* :nodoc: */
static VALUE
random_dump(VALUE obj)
{
rb_random_t *rnd = get_rnd(obj);
VALUE dump = rb_ary_new2(3);
rb_ary_push(dump, mt_state(&rnd->mt));
rb_ary_push(dump, INT2FIX(rnd->mt.left));
rb_ary_push(dump, rnd->seed);
return dump;
}
/* :nodoc: */
static VALUE
random_load(VALUE obj, VALUE dump)
{
rb_random_t *rnd = get_rnd(obj);
struct MT *mt = &rnd->mt;
VALUE state, left = INT2FIX(1), seed = INT2FIX(0);
VALUE *ary;
unsigned long x;
Check_Type(dump, T_ARRAY);
ary = RARRAY_PTR(dump);
switch (RARRAY_LEN(dump)) {
case 3:
seed = ary[2];
case 2:
left = ary[1];
case 1:
state = ary[0];
break;
default:
rb_raise(rb_eArgError, "wrong dump data");
}
memset(mt->state, 0, sizeof(mt->state));
if (FIXNUM_P(state)) {
x = FIX2ULONG(state);
mt->state[0] = (unsigned int)x;
#if SIZEOF_LONG / SIZEOF_INT >= 2
mt->state[1] = (unsigned int)(x >> BITSPERDIG);
#endif
#if SIZEOF_LONG / SIZEOF_INT >= 3
mt->state[2] = (unsigned int)(x >> 2 * BITSPERDIG);
#endif
#if SIZEOF_LONG / SIZEOF_INT >= 4
mt->state[3] = (unsigned int)(x >> 3 * BITSPERDIG);
#endif
}
else {
BDIGIT *d;
long len;
Check_Type(state, T_BIGNUM);
len = RBIGNUM_LEN(state);
if (len > roomof(sizeof(mt->state), SIZEOF_BDIGITS)) {
len = roomof(sizeof(mt->state), SIZEOF_BDIGITS);
}
#if SIZEOF_BDIGITS < SIZEOF_INT
else if (len % DIGSPERINT) {
d = RBIGNUM_DIGITS(state) + len;
# if DIGSPERINT == 2
--len;
x = *--d;
# else
x = 0;
do {
x = (x << BITSPERDIG) | *--d;
} while (--len % DIGSPERINT);
# endif
mt->state[len / DIGSPERINT] = (unsigned int)x;
}
#endif
if (len > 0) {
d = BDIGITS(state) + len;
do {
--len;
x = *--d;
# if DIGSPERINT == 2
--len;
x = (x << BITSPERDIG) | *--d;
# elif SIZEOF_BDIGITS < SIZEOF_INT
do {
x = (x << BITSPERDIG) | *--d;
} while (--len % DIGSPERINT);
# endif
mt->state[len / DIGSPERINT] = (unsigned int)x;
} while (len > 0);
}
}
x = NUM2ULONG(left);
if (x > numberof(mt->state)) {
rb_raise(rb_eArgError, "wrong value");
}
mt->left = (unsigned int)x;
mt->next = mt->state + numberof(mt->state) - x + 1;
rnd->seed = rb_to_int(seed);
return obj;
}
/*
* call-seq:
* srand(number=0) -> old_seed
*
* Seeds the pseudorandom number generator to the value of
* <i>number</i>. If <i>number</i> is omitted,
* seeds the generator using a combination of the time, the
* process id, and a sequence number. (This is also the behavior if
* <code>Kernel::rand</code> is called without previously calling
* <code>srand</code>, but without the sequence.) By setting the seed
* to a known value, scripts can be made deterministic during testing.
* The previous seed value is returned. Also see <code>Kernel::rand</code>.
*/
static VALUE
rb_f_srand(int argc, VALUE *argv, VALUE obj)
{
VALUE seed, old;
rb_random_t *r = &default_rand;
rb_secure(4);
if (argc == 0) {
seed = random_seed();
}
else {
rb_scan_args(argc, argv, "01", &seed);
}
old = r->seed;
r->seed = rand_init(&r->mt, seed);
return old;
}
static unsigned long
make_mask(unsigned long x)
{
x = x | x >> 1;
x = x | x >> 2;
x = x | x >> 4;
x = x | x >> 8;
x = x | x >> 16;
#if 4 < SIZEOF_LONG
x = x | x >> 32;
#endif
return x;
}
static unsigned long
limited_rand(struct MT *mt, unsigned long limit)
{
/* mt must be initialized */
int i;
unsigned long val, mask;
if (!limit) return 0;
mask = make_mask(limit);
retry:
val = 0;
for (i = SIZEOF_LONG/SIZEOF_INT32-1; 0 <= i; i--) {
if ((mask >> (i * 32)) & 0xffffffff) {
val |= (unsigned long)genrand_int32(mt) << (i * 32);
val &= mask;
if (limit < val)
goto retry;
}
}
return val;
}
static VALUE
limited_big_rand(struct MT *mt, struct RBignum *limit)
{
/* mt must be initialized */
unsigned long mask, lim, rnd;
struct RBignum *val;
long i, len;
int boundary;
len = (RBIGNUM_LEN(limit) * SIZEOF_BDIGITS + 3) / 4;
val = (struct RBignum *)rb_big_clone((VALUE)limit);
RBIGNUM_SET_SIGN(val, 1);
#if SIZEOF_BDIGITS == 2
# define BIG_GET32(big,i) \
(RBIGNUM_DIGITS(big)[(i)*2] | \
((i)*2+1 < RBIGNUM_LEN(big) ? \
(RBIGNUM_DIGITS(big)[(i)*2+1] << 16) : \
0))
# define BIG_SET32(big,i,d) \
((RBIGNUM_DIGITS(big)[(i)*2] = (d) & 0xffff), \
((i)*2+1 < RBIGNUM_LEN(big) ? \
(RBIGNUM_DIGITS(big)[(i)*2+1] = (d) >> 16) : \
0))
#else
/* SIZEOF_BDIGITS == 4 */
# define BIG_GET32(big,i) (RBIGNUM_DIGITS(big)[(i)])
# define BIG_SET32(big,i,d) (RBIGNUM_DIGITS(big)[(i)] = (d))
#endif
retry:
mask = 0;
boundary = 1;
for (i = len-1; 0 <= i; i--) {
lim = BIG_GET32(limit, i);
mask = mask ? 0xffffffff : make_mask(lim);
if (mask) {
rnd = genrand_int32(mt) & mask;
if (boundary) {
if (lim < rnd)
goto retry;
if (rnd < lim)
boundary = 0;
}
}
else {
rnd = 0;
}
BIG_SET32(val, i, (BDIGIT)rnd);
}
return rb_big_norm((VALUE)val);
}
/*
* Returns random unsigned long value in [0, _limit_].
*
* Note that _limit_ is included, and the range of the argument and the
* return value depends on environments.
*/
unsigned long
rb_genrand_ulong_limited(unsigned long limit)
{
return limited_rand(default_mt(), limit);
}
unsigned int
rb_random_int32(VALUE obj)
{
rb_random_t *rnd = try_get_rnd(obj);
if (!rnd) {
#if SIZEOF_LONG * CHAR_BIT > 32
VALUE lim = ULONG2NUM(0x100000000);
#elif defined HAVE_LONG_LONG
VALUE lim = ULL2NUM((LONG_LONG)0xffffffff+1);
#else
VALUE lim = rb_big_plus(ULONG2NUM(0xffffffff), INT2FIX(1));
#endif
return (unsigned int)NUM2ULONG(rb_funcall2(obj, id_rand, 1, &lim));
}
return genrand_int32(&rnd->mt);
}
double
rb_random_real(VALUE obj)
{
rb_random_t *rnd = try_get_rnd(obj);
if (!rnd) {
VALUE v = rb_funcall2(obj, id_rand, 0, 0);
double d = NUM2DBL(v);
if (d < 0.0 || d >= 1.0) {
rb_raise(rb_eRangeError, "random number too big %g", d);
}
return d;
}
return genrand_real(&rnd->mt);
}
/*
* call-seq: prng.bytes(size) -> a_string
*
* Returns a random binary string. The argument size specified the length of
* the result string.
*/
static VALUE
random_bytes(VALUE obj, VALUE len)
{
return rb_random_bytes(obj, NUM2LONG(rb_to_int(len)));
}
VALUE
rb_random_bytes(VALUE obj, long n)
{
rb_random_t *rnd = try_get_rnd(obj);
VALUE bytes;
char *ptr;
unsigned int r, i;
if (!rnd) {
VALUE len = LONG2NUM(n);
return rb_funcall2(obj, id_bytes, 1, &len);
}
bytes = rb_str_new(0, n);
ptr = RSTRING_PTR(bytes);
for (; n >= SIZEOF_INT32; n -= SIZEOF_INT32) {
r = genrand_int32(&rnd->mt);
i = SIZEOF_INT32;
do {
*ptr++ = (char)r;
r >>= CHAR_BIT;
} while (--i);
}
if (n > 0) {
r = genrand_int32(&rnd->mt);
do {
*ptr++ = (char)r;
r >>= CHAR_BIT;
} while (--n);
}
return bytes;
}
static VALUE
range_values(VALUE vmax, VALUE *begp, VALUE *endp, int *exclp)
{
VALUE end, r;
if (!rb_range_values(vmax, begp, &end, exclp)) return Qfalse;
if (endp) *endp = end;
if (!rb_respond_to(end, id_minus)) return Qfalse;
r = rb_funcall2(end, id_minus, 1, begp);
if (NIL_P(r)) return Qfalse;
return r;
}
static VALUE
rand_int(struct MT *mt, VALUE vmax, int restrictive)
{
/* mt must be initialized */
long max;
unsigned long r;
if (FIXNUM_P(vmax)) {
max = FIX2LONG(vmax);
if (!max) return Qnil;
if (max < 0) {
if (restrictive) return Qnil;
max = -max;
}
r = limited_rand(mt, (unsigned long)max - 1);
return ULONG2NUM(r);
}