diff options
Diffstat (limited to 'random.c')
| -rw-r--r-- | random.c | 87 |
1 files changed, 58 insertions, 29 deletions
@@ -898,17 +898,20 @@ rb_genrand_ulong_limited(unsigned long limit) return limited_rand(default_mt(), limit); } -static unsigned int -obj_random_int32(VALUE obj) -{ -#if SIZEOF_LONG * CHAR_BIT > 32 - VALUE lim = ULONG2NUM(0x100000000UL); -#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)); +static VALUE +obj_random_bytes(VALUE obj, void *p, long n) +{ + VALUE len = LONG2NUM(n); + VALUE v = rb_funcallv_public(obj, id_bytes, 1, &len); + long l; + Check_Type(v, T_STRING); + l = RSTRING_LEN(v); + if (l < n) + rb_raise(rb_eRangeError, "random data too short %ld", l); + else if (l > n) + rb_raise(rb_eRangeError, "random data too long %ld", l); + if (p) memcpy(p, RSTRING_PTR(v), n); + return v; } static unsigned int @@ -922,7 +925,9 @@ rb_random_int32(VALUE obj) { rb_random_t *rnd = try_get_rnd(obj); if (!rnd) { - return obj_random_int32(obj); + uint32_t x; + obj_random_bytes(obj, &x, sizeof(x)); + return (unsigned int)x; } return random_int32(rnd); } @@ -933,8 +938,10 @@ random_real(VALUE obj, rb_random_t *rnd, int excl) uint32_t a, b; if (!rnd) { - a = obj_random_int32(obj); - b = obj_random_int32(obj); + uint32_t x[2] = {0, 0}; + obj_random_bytes(obj, x, sizeof(x)); + a = x[0]; + b = x[1]; } else { a = random_int32(rnd); @@ -982,6 +989,22 @@ ulong_to_num_plus_1(unsigned long n) static unsigned long random_ulong_limited(VALUE obj, rb_random_t *rnd, unsigned long limit) { + if (!limit) return 0; + if (!rnd) { + unsigned long val, mask = make_mask(limit); + do { + obj_random_bytes(obj, &val, sizeof(unsigned long)); + val &= mask; + } while (limit < val); + return val; + } + return limited_rand(&rnd->mt, limit); +} + +unsigned long +rb_random_ulong_limited(VALUE obj, unsigned long limit) +{ + rb_random_t *rnd = try_get_rnd(obj); if (!rnd) { VALUE lim = ulong_to_num_plus_1(limit); VALUE v = rb_to_int(rb_funcall2(obj, id_rand, 1, &lim)); @@ -1001,25 +1024,31 @@ static VALUE random_ulong_limited_big(VALUE obj, rb_random_t *rnd, VALUE vmax) { if (!rnd) { - VALUE lim = rb_big_plus(vmax, INT2FIX(1)); - VALUE v = rb_to_int(rb_funcall2(obj, id_rand, 1, &lim)); - if (rb_num_negative_p(v)) { - rb_raise(rb_eRangeError, "random number too small %"PRIsVALUE, v); - } - if (FIX2LONG(rb_big_cmp(vmax, v)) < 0) { - rb_raise(rb_eRangeError, "random number too big %"PRIsVALUE, v); + VALUE v, vtmp; + size_t i, nlz, len = rb_absint_numwords(vmax, 32, &nlz); + uint32_t *tmp = ALLOCV_N(uint32_t, vtmp, len * 2); + uint32_t mask = (uint32_t)~0 >> nlz; + uint32_t *lim_array = tmp; + uint32_t *rnd_array = tmp + len; + int flag = INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER; + rb_integer_pack(vmax, lim_array, len, sizeof(uint32_t), 0, flag); + + retry: + obj_random_bytes(obj, rnd_array, len * sizeof(uint32_t)); + rnd_array[0] &= mask; + for (i = 0; i < len; ++i) { + if (lim_array[i] < rnd_array[i]) + goto retry; + if (rnd_array[i] < lim_array[i]) + break; } + v = rb_integer_unpack(rnd_array, len, sizeof(uint32_t), 0, flag); + ALLOCV_END(vtmp); return v; } return limited_big_rand(&rnd->mt, vmax); } -unsigned long -rb_random_ulong_limited(VALUE obj, unsigned long limit) -{ - return random_ulong_limited(obj, try_get_rnd(obj), limit); -} - static VALUE genrand_bytes(rb_random_t *rnd, long n); /* @@ -1068,8 +1097,7 @@ rb_random_bytes(VALUE obj, long n) { rb_random_t *rnd = try_get_rnd(obj); if (!rnd) { - VALUE len = LONG2NUM(n); - return rb_funcall2(obj, id_bytes, 1, &len); + return obj_random_bytes(obj, NULL, n); } return genrand_bytes(rnd, n); } @@ -1601,6 +1629,7 @@ InitVM_Random(void) VALUE m = rb_define_module_under(rb_cRandom, "Formatter"); rb_include_module(rb_cRandom, m); rb_define_method(m, "random_number", rand_random_number, -1); + rb_define_method(m, "rand", rand_random_number, -1); } } |