relay_server/utils/
pick.rs

1/// Returns `true` if `id` is rolled out with a rollout rate `rate`.
2///
3/// Deterministically makes a rollout decision for an id, usually organization id,
4/// and rate.
5pub fn is_rolled_out(id: u64, rate: f32) -> bool {
6    ((id % 100000) as f32 / 100000.0f32) < rate
7}
8
9/// Returns `true` if the current item should be sampled.
10///
11/// The passed `rate` is expected to be `0 <= rate <= 1`.
12pub fn sample(rate: f32) -> bool {
13    (rate >= 1.0) || (rate > 0.0 && rand::random::<f32>() < rate)
14}
15
16#[cfg(test)]
17mod test {
18    use super::*;
19
20    #[test]
21    fn test_rollout() {
22        assert!(!is_rolled_out(1, 0.0));
23        assert!(is_rolled_out(1, 0.0001)); // Id 1 should always be rolled out
24        assert!(is_rolled_out(1, 0.1));
25        assert!(is_rolled_out(1, 0.9));
26        assert!(is_rolled_out(1, 1.0));
27
28        assert!(!is_rolled_out(0, 0.0));
29        assert!(is_rolled_out(0, 1.0));
30        assert!(!is_rolled_out(100000, 0.0));
31        assert!(is_rolled_out(100000, 1.0));
32        assert!(!is_rolled_out(100001, 0.0));
33        assert!(is_rolled_out(100001, 1.0));
34
35        assert!(!is_rolled_out(42, -100.0));
36        assert!(is_rolled_out(42, 100.0));
37    }
38
39    #[test]
40    fn test_sample() {
41        assert!(sample(1.0));
42        assert!(!sample(0.0));
43
44        let mut r: i64 = 0;
45        for _ in 0..10000 {
46            if sample(0.5) {
47                r += 1;
48            } else {
49                r -= 1;
50            }
51        }
52        assert!(r.abs() < 500);
53    }
54}
relay_server/utils/pick.rs

relay_server/utils/
pick.rs
