1 files changed, 100 insertions, 0 deletions
diff --git a/ext/-test-/random/loop.c b/ext/-test-/random/loop.c
new file mode 100644
index 0000000000..92af1a9b18
--- /dev/null
+++ b/ext/-test-/random/loop.c
@@ -0,0 +1,100 @@
+#include "ruby/random.h"
+
+static const uint32_t max_seeds = 1024;
+
+typedef struct {
+    rb_random_t base;
+    uint32_t num, idx, *buf;
+} rand_loop_t;
+
+RB_RANDOM_INTERFACE_DECLARE(loop)
+static const rb_random_interface_t random_loop_if = {
+    32,
+    RB_RANDOM_INTERFACE_DEFINE(loop)
+};
+
+static size_t
+random_loop_memsize(const void *ptr)
+{
+    const rand_loop_t *r = ptr;
+    return sizeof(*r) + r->num * sizeof(r->buf[0]);
+}
+
+static rb_random_data_type_t random_loop_type = {
+    "random/loop",
+    {
+        rb_random_mark,
+        RUBY_TYPED_DEFAULT_FREE,
+        random_loop_memsize,
+    },
+    RB_RANDOM_PARENT,
+    (void *)&random_loop_if,
+    RUBY_TYPED_FREE_IMMEDIATELY
+};
+
+
+static VALUE
+loop_alloc(VALUE klass)
+{
+    rand_loop_t *rnd;
+    VALUE obj = TypedData_Make_Struct(klass, rand_loop_t, &random_loop_type, rnd);
+    rnd->base.seed = INT2FIX(0);
+    return obj;
+}
+
+static void
+loop_init(rb_random_t *rnd, const uint32_t *buf, size_t len)
+{
+    rand_loop_t *r = (rand_loop_t *)rnd;
+
+    if (len > max_seeds) len = max_seeds;
+
+    REALLOC_N(r->buf, uint32_t, len);
+    MEMCPY(r->buf, buf, uint32_t, (r->num = (uint32_t)len));
+}
+
+static void
+loop_get_bytes(rb_random_t *rnd, void *p, size_t n)
+{
+    uint8_t *buf = p;
+    while (n > 0) {
+        uint32_t x = loop_get_int32(rnd);
+        switch (n % 4) {
+          case 0:
+            *buf++ = (uint8_t)x;
+            n--;
+          case 3:
+            *buf++ = (uint8_t)x;
+            n--;
+          case 2:
+            *buf++ = (uint8_t)x;
+            n--;
+          case 1:
+            *buf++ = (uint8_t)x;
+            n--;
+        }
+    }
+}
+
+static uint32_t
+loop_get_int32(rb_random_t *rnd)
+{
+    rand_loop_t *r = (rand_loop_t *)rnd;
+    if (r->idx < r->num) {
+        uint32_t x = r->buf[r->idx++];
+        if (r->idx >= r->num) r->idx = 0;
+        return x;
+    }
+    else if (r->num) {
+        return r->buf[r->idx = 0];
+    }
+    return 0;
+}
+
+void
+Init_random_loop(VALUE mod, VALUE base)
+{
+    VALUE c = rb_define_class_under(mod, "Loop", base);
+    rb_define_alloc_func(c, loop_alloc);
+    RB_RANDOM_DATA_INIT_PARENT(random_loop_type);
+}