bench mycelium round trips

1 files changed, 32 insertions, 0 deletions

diff --git a/src/simtest/bench.rs b/src/simtest/bench.rs
index d5ca624..06b557e 100644
--- a/src/simtest/bench.rs
+++ b/src/simtest/bench.rs
@@ -105,6 +105,28 @@ fn lossy(sim: &Sim, _: &[String]) {
     });
 }
 
+/// As `lossy`, but each link with a latency of its own, as over Mycelium: round trips
+/// from 20 to 250 ms, each message within a fifth of its link's. So what the uniform
+/// 50–500 ms of `lossy` gives that real links don't: messages on one link overtake each
+/// other only within the jitter, and the fast links to a node are fast every time.
+fn mycelium_like(sim: &Sim, ids: &[String]) {
+    let mut rng = crate::testrand::Rng::new(7);
+    for (i, from) in ids.iter().enumerate() {
+        for to in &ids[i + 1..] {
+            let rtt_ms = 20.0 + rng.next_f64() * 230.0;
+            let half = Duration::from_secs_f64(rtt_ms / 2.0 / 1000.0);
+            let link = LinkParams {
+                loss: 0.02,
+                duplicate: 0.01,
+                delay: (half * 4 / 5, half * 6 / 5),
+                ..LinkParams::default()
+            };
+            sim.net.set_link(from, to, link.clone());
+            sim.net.set_link(to, from, link);
+        }
+    }
+}
+
 const SCENARIOS: &[Scenario] = &[
     Scenario {
         name: "full mesh, 13 nodes",
@@ -178,6 +200,16 @@ const SCENARIOS: &[Scenario] = &[
         away: None,
         joining: 5,
     },
+    // Last, so the others keep their seeds.
+    Scenario {
+        name: "partial mesh, lossy links with Mycelium's round trips, 50 nodes",
+        nodes: 50,
+        on: sim_only,
+        net: mycelium_like,
+        writer: 1,
+        away: None,
+        joining: 0,
+    },
 ];
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 16)]