Implement ID tracking, start dumping ideas into rbx_session

server/src/id.rs

@@ -0,0 +1,21 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+/// A unique identifier, not guaranteed to be generated in any order.
+pub type Id = usize;
+
+lazy_static! {
+    static ref LAST_ID: AtomicUsize = AtomicUsize::new(0);
+}
+
+/// Generate a new ID, which has no defined ordering.
+pub fn get_id() -> Id {
+    LAST_ID.fetch_add(1, Ordering::SeqCst)
+}
+
+#[test]
+fn it_gives_unique_numbers() {
+    let a = get_id();
+    let b = get_id();
+
+    assert!(a != b);
+}