1 files changed, 21 insertions, 0 deletions
diff --git a/src/stats/rand_util.rs b/src/stats/rand_util.rs
new file mode 100755
index 0000000..ed374cf
--- /dev/null
+++ b/src/stats/rand_util.rs
@@ -0,0 +1,21 @@
+use oorandom::Rand64;
+use std::cell::RefCell;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+pub type Rng = Rand64;
+
+thread_local! {
+    static SEED_RAND: RefCell<Rand64> = RefCell::new(Rand64::new(
+        SystemTime::now().duration_since(UNIX_EPOCH)
+            .expect("Time went backwards")
+            .as_millis()
+    ));
+}
+
+pub fn new_rng() -> Rng {
+    SEED_RAND.with(|r| {
+        let mut r = r.borrow_mut();
+        let seed = ((r.rand_u64() as u128) << 64) | (r.rand_u64() as u128);
+        Rand64::new(seed)
+    })
+}