Diff: mrbgems/mruby-random/random.c

Revision:

0:158c61bb030f

diff -r 000000000000 -r 158c61bb030f mrbgems/mruby-random/random.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mrbgems/mruby-random/random.c	Wed Mar 25 17:36:16 2015 +0000
@@ -0,0 +1,346 @@
+/*
+** random.c - Random module
+**
+** See Copyright Notice in mruby.h
+*/
+
+#include "mruby.h"
+#include "mruby/variable.h"
+#include "mruby/class.h"
+#include "mruby/data.h"
+#include "mruby/array.h"
+#include "mt19937ar.h"
+
+#include <time.h>
+
+static char const MT_STATE_KEY[] = "$mrb_i_mt_state";
+
+static const struct mrb_data_type mt_state_type = {
+  MT_STATE_KEY, mrb_free,
+};
+
+static mrb_value mrb_random_rand(mrb_state *mrb, mrb_value self);
+static mrb_value mrb_random_srand(mrb_state *mrb, mrb_value self);
+
+static void
+mt_srand(mt_state *t, unsigned long seed)
+{
+  mrb_random_init_genrand(t, seed);
+}
+
+static unsigned long
+mt_rand(mt_state *t)
+{
+  return mrb_random_genrand_int32(t);
+}
+
+static double
+mt_rand_real(mt_state *t)
+{
+  return mrb_random_genrand_real1(t);
+}
+
+static mrb_value
+mrb_random_mt_srand(mrb_state *mrb, mt_state *t, mrb_value seed)
+{
+  if (mrb_nil_p(seed)) {
+    seed = mrb_fixnum_value((mrb_int)(time(NULL) + mt_rand(t)));
+    if (mrb_fixnum(seed) < 0) {
+      seed = mrb_fixnum_value(0 - mrb_fixnum(seed));
+    }
+  }
+
+  mt_srand(t, (unsigned) mrb_fixnum(seed));
+
+  return seed;
+}
+
+static mrb_value
+mrb_random_mt_rand(mrb_state *mrb, mt_state *t, mrb_value max)
+{
+  mrb_value value;
+
+  if (mrb_fixnum(max) == 0) {
+    value = mrb_float_value(mrb, mt_rand_real(t));
+  }
+  else {
+    value = mrb_fixnum_value(mt_rand(t) % mrb_fixnum(max));
+  }
+
+  return value;
+}
+
+static mrb_value
+get_opt(mrb_state* mrb)
+{
+  mrb_value arg;
+
+  arg = mrb_nil_value();
+  mrb_get_args(mrb, "|o", &arg);
+
+  if (!mrb_nil_p(arg)) {
+    if (!mrb_fixnum_p(arg)) {
+      mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid argument type");
+    }
+    arg = mrb_check_convert_type(mrb, arg, MRB_TT_FIXNUM, "Fixnum", "to_int");
+    if (mrb_fixnum(arg) < 0) {
+      arg = mrb_fixnum_value(0 - mrb_fixnum(arg));
+    }
+  }
+  return arg;
+}
+
+static mrb_value
+get_random(mrb_state *mrb) {
+  return mrb_const_get(mrb,
+             mrb_obj_value(mrb_class_get(mrb, "Random")),
+             mrb_intern_lit(mrb, "DEFAULT"));
+}
+
+static mt_state *
+get_random_state(mrb_state *mrb)
+{
+  mrb_value random_val = get_random(mrb);
+  return DATA_GET_PTR(mrb, random_val, &mt_state_type, mt_state);
+}
+
+static mrb_value
+mrb_random_g_rand(mrb_state *mrb, mrb_value self)
+{
+  mrb_value random = get_random(mrb);
+  return mrb_random_rand(mrb, random);
+}
+
+static mrb_value
+mrb_random_g_srand(mrb_state *mrb, mrb_value self)
+{
+  mrb_value random = get_random(mrb);
+  return mrb_random_srand(mrb, random);
+}
+
+static mrb_value
+mrb_random_init(mrb_state *mrb, mrb_value self)
+{
+  mrb_value seed;
+  mt_state *t;
+
+  /* avoid memory leaks */
+  t = (mt_state*)DATA_PTR(self);
+  if (t) {
+    mrb_free(mrb, t);
+  }
+  mrb_data_init(self, NULL, &mt_state_type);
+
+  t = (mt_state *)mrb_malloc(mrb, sizeof(mt_state));
+  t->mti = N + 1;
+
+  seed = get_opt(mrb);
+  seed = mrb_random_mt_srand(mrb, t, seed);
+  if (mrb_nil_p(seed)) {
+    t->has_seed = FALSE;
+  }
+  else {
+    mrb_assert(mrb_fixnum_p(seed));
+    t->has_seed = TRUE;
+    t->seed = mrb_fixnum(seed);
+  }
+
+  mrb_data_init(self, t, &mt_state_type);
+
+  return self;
+}
+
+static void
+mrb_random_rand_seed(mrb_state *mrb, mt_state *t)
+{
+  if (!t->has_seed) {
+    mrb_random_mt_srand(mrb, t, mrb_nil_value());
+  }
+}
+
+static mrb_value
+mrb_random_rand(mrb_state *mrb, mrb_value self)
+{
+  mrb_value max;
+  mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
+
+  max = get_opt(mrb);
+  mrb_random_rand_seed(mrb, t);
+  return mrb_random_mt_rand(mrb, t, max);
+}
+
+static mrb_value
+mrb_random_srand(mrb_state *mrb, mrb_value self)
+{
+  mrb_value seed;
+  mrb_value old_seed;
+  mt_state *t = DATA_GET_PTR(mrb, self, &mt_state_type, mt_state);
+
+  seed = get_opt(mrb);
+  seed = mrb_random_mt_srand(mrb, t, seed);
+  old_seed = t->has_seed? mrb_fixnum_value(t->seed) : mrb_nil_value();
+  if (mrb_nil_p(seed)) {
+    t->has_seed = FALSE;
+  }
+  else {
+    mrb_assert(mrb_fixnum_p(seed));
+    t->has_seed = TRUE;
+    t->seed = mrb_fixnum(seed);
+  }
+
+  return old_seed;
+}
+
+/*
+ *  call-seq:
+ *     ary.shuffle!   ->   ary
+ *
+ *  Shuffles elements in self in place.
+ */
+
+static mrb_value
+mrb_ary_shuffle_bang(mrb_state *mrb, mrb_value ary)
+{
+  mrb_int i;
+  mt_state *random = NULL;
+
+  if (RARRAY_LEN(ary) > 1) {
+    mrb_get_args(mrb, "|d", &random, &mt_state_type);
+
+    if (random == NULL) {
+      random = get_random_state(mrb);
+    }
+    mrb_random_rand_seed(mrb, random);
+
+    mrb_ary_modify(mrb, mrb_ary_ptr(ary));
+
+    for (i = RARRAY_LEN(ary) - 1; i > 0; i--)  {
+      mrb_int j;
+      mrb_value tmp;
+
+      j = mrb_fixnum(mrb_random_mt_rand(mrb, random, mrb_fixnum_value(RARRAY_LEN(ary))));
+
+      tmp = RARRAY_PTR(ary)[i];
+      mrb_ary_ptr(ary)->ptr[i] = RARRAY_PTR(ary)[j];
+      mrb_ary_ptr(ary)->ptr[j] = tmp;
+    }
+  }
+
+  return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.shuffle   ->   new_ary
+ *
+ *  Returns a new array with elements of self shuffled.
+ */
+
+static mrb_value
+mrb_ary_shuffle(mrb_state *mrb, mrb_value ary)
+{
+  mrb_value new_ary = mrb_ary_new_from_values(mrb, RARRAY_LEN(ary), RARRAY_PTR(ary));
+  mrb_ary_shuffle_bang(mrb, new_ary);
+
+  return new_ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.sample      ->   obj
+ *     ary.sample(n)   ->   new_ary
+ *
+ *  Choose a random element or +n+ random elements from the array.
+ *
+ *  The elements are chosen by using random and unique indices into the array
+ *  in order to ensure that an element doesn't repeat itself unless the array
+ *  already contained duplicate elements.
+ *
+ *  If the array is empty the first form returns +nil+ and the second form
+ *  returns an empty array.
+ */
+
+static mrb_value
+mrb_ary_sample(mrb_state *mrb, mrb_value ary)
+{
+  mrb_int n = 0;
+  mrb_bool given;
+  mt_state *random = NULL;
+  mrb_int len = RARRAY_LEN(ary);
+
+  mrb_get_args(mrb, "|i?d", &n, &given, &random, &mt_state_type);
+  if (random == NULL) {
+    random = get_random_state(mrb);
+  }
+  mrb_random_rand_seed(mrb, random);
+  mt_rand(random);
+  if (!given) {                 /* pick one element */
+    switch (len) {
+    case 0:
+      return mrb_nil_value();
+    case 1:
+      return RARRAY_PTR(ary)[0];
+    default:
+      return RARRAY_PTR(ary)[mt_rand(random) % len];
+    }
+  }
+  else {
+    mrb_value result;
+    mrb_int i, j;
+
+    if (n < 0) mrb_raise(mrb, E_ARGUMENT_ERROR, "negative sample number");
+    if (n > len) n = len;
+    result = mrb_ary_new_capa(mrb, n);
+    for (i=0; i<n; i++) {
+      mrb_int r;
+
+      for (;;) {
+      retry:
+        r = mt_rand(random) % len;
+
+        for (j=0; j<i; j++) {
+          if (mrb_fixnum(RARRAY_PTR(result)[j]) == r) {
+            goto retry;         /* retry if duplicate */
+          }
+        }
+        break;
+      }
+      mrb_ary_push(mrb, result, mrb_fixnum_value(r));
+    }
+    for (i=0; i<n; i++) {
+      mrb_ary_set(mrb, result, i, RARRAY_PTR(ary)[mrb_fixnum(RARRAY_PTR(result)[i])]);
+    }
+    return result;
+  }
+}
+
+
+void mrb_mruby_random_gem_init(mrb_state *mrb)
+{
+  struct RClass *random;
+  struct RClass *array = mrb->array_class;
+
+  mrb_define_method(mrb, mrb->kernel_module, "rand", mrb_random_g_rand, MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, mrb->kernel_module, "srand", mrb_random_g_srand, MRB_ARGS_OPT(1));
+
+  random = mrb_define_class(mrb, "Random", mrb->object_class);
+  MRB_SET_INSTANCE_TT(random, MRB_TT_DATA);
+  mrb_define_class_method(mrb, random, "rand", mrb_random_g_rand, MRB_ARGS_OPT(1));
+  mrb_define_class_method(mrb, random, "srand", mrb_random_g_srand, MRB_ARGS_OPT(1));
+
+  mrb_define_method(mrb, random, "initialize", mrb_random_init, MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, random, "rand", mrb_random_rand, MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, random, "srand", mrb_random_srand, MRB_ARGS_OPT(1));
+
+  mrb_define_method(mrb, array, "shuffle", mrb_ary_shuffle, MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, array, "shuffle!", mrb_ary_shuffle_bang, MRB_ARGS_OPT(1));
+  mrb_define_method(mrb, array, "sample", mrb_ary_sample, MRB_ARGS_OPT(2));
+
+  mrb_const_set(mrb, mrb_obj_value(random), mrb_intern_lit(mrb, "DEFAULT"),
+          mrb_obj_new(mrb, random, 0, NULL));
+}
+
+void mrb_mruby_random_gem_final(mrb_state *mrb)
+{
+}
+