fix: previous lognormal crate was requiring java. Implemented in pure…

… Rust now
beltram · Jun 13, 2023 · 29089c9 · 29089c9
1 parent 7c1e315
commit 29089c9
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Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
@@ -45,7 +45,7 @@ rand = "0.8"
 regex-syntax = { version = "0.6", default-features = false }
 rand_regex = { version = "0.15", default-features = false }
 thiserror = "1.0"
-jandom = "0.3"
+rand_distr = "0.4"
 
 isahc = { version = "1.7", optional = true, default-features = false }
 reqwest = { version = "0.11", optional = true, default-features = false }

diff --git a/lib/src/wiremock/delay.rs b/lib/src/wiremock/delay.rs
@@ -8,9 +8,12 @@ pub struct LognormalDelay {
 impl LognormalDelay {
     /// see [https://github.com/wiremock/wiremock/blob/60e9e858068548786af4a1a434b52fd1376c4d43/src/main/java/com/github/tomakehurst/wiremock/http/LogNormal.java#L52]
     pub fn new_sample(&self) -> core::time::Duration {
-        let seed = rand::random::<i64>();
-        let rand = jandom::Random::new(seed).next_gaussian();
-        let milli = ((rand * self.sigma).exp() * self.median as f64).round() as u64;
+        let mean = self.median as f64;
+        // TODO: error handling
+        let normal = rand_distr::LogNormal::new(mean.ln(), self.sigma).unwrap();
+
+        use rand_distr::Distribution as _;
+        let milli = normal.sample(&mut rand::thread_rng()) as u64;
         core::time::Duration::from_millis(milli)
     }
 }