Support huge (>1e9 element/sec) quotas

.github/workflows/tests.yml

@@ -20,6 +20,7 @@ jobs:
     secrets: "inherit"
     uses: "boinkor-net/ci-baseline-rust/.github/workflows/ci_baseline_rust_tests.yml@main"
     strategy:
+      fail-fast: false
       matrix:
         rust_toolchain: [nightly, stable]
         cargo_test_args:

governor/CHANGELOG.md

@@ -4,6 +4,17 @@
 
 ## [Unreleased] - ReleaseDate
 
+### Changed
+
+* The `.per_second` constructor for `Quota` now constructs a quota
+  that ensures all rate-limiting calls succeed when given values in
+  excess of 1 billion (previously, this would result in rate limiters
+  that would incorrectly reject values). Reported in
+  [#203](https://github.com/antifuchs/governor/issues/203).
+
+### Contributors
+* [@rkd-msw](https://github.com/rkd-msw)
+
 ## [[0.6.0](https://docs.rs/governor/0.6.0/governor/)] - 2023-07-12
 
 ### Added

governor/src/gcra.rs

@@ -85,7 +85,9 @@ pub(crate) struct Gcra {
 
 impl Gcra {
     pub(crate) fn new(quota: Quota) -> Self {
-        let tau: Nanos = (quota.replenish_1_per * quota.max_burst.get()).into();
+        let tau: Nanos = (cmp::max(quota.replenish_1_per, Duration::from_nanos(1))
+            * quota.max_burst.get())
+        .into();
         let t: Nanos = quota.replenish_1_per.into();
         Gcra { t, tau }
     }

governor/tests/direct.rs

@@ -162,3 +162,27 @@ fn default_direct() {
         RateLimiter::direct_with_clock(Quota::per_second(nonzero!(20u32)), &clock);
     assert_eq!(Ok(()), limiter.check());
 }
+
+#[cfg(feature = "std")]
+#[test]
+fn stresstest_large_quotas() {
+    use std::{sync::Arc, thread};
+
+    use governor::middleware::StateInformationMiddleware;
+
+    let quota = Quota::per_second(nonzero!(1_000_000_001u32));
+    let rate_limiter =
+        Arc::new(RateLimiter::direct(quota).with_middleware::<StateInformationMiddleware>());
+
+    fn rlspin(rl: Arc<DefaultDirectRateLimiter<StateInformationMiddleware>>) {
+        for _ in 0..1_000_000 {
+            rl.check().map_err(|e| dbg!(e)).unwrap();
+        }
+    }
+
+    let rate_limiter2 = rate_limiter.clone();
+    thread::spawn(move || {
+        rlspin(rate_limiter2);
+    });
+    rlspin(rate_limiter);
+}