feat(irtt): make IRTT measurement optional and refine engine behavior

Conditionally compile IRTT functionality behind the `irtt` feature flag to allow building smaller binaries without IRTT dependencies. Enhance IRTT engine shutdown, configuration, and clarify ICMP protocol names.

src/main.rs

@@ -22,6 +22,7 @@ mod util;
 use crate::baseliner::Baseliner;
 use crate::controller::Controller;
 use crate::measurement::icmp::IcmpEngine;
+#[cfg(feature = "irtt")]
 use crate::measurement::irtt::IrttEngine;
 use crate::measurement::model::{MeasurementSource, MeasurementStream};
 use crate::metrics::{Metric, Metrics, MetricsSender};
@@ -279,6 +280,12 @@ fn wait_for_exit(error_rx: &flume::Receiver<anyhow::Error>) -> anyhow::Result<()
 }
 
 fn run(settings: &Settings) -> anyhow::Result<()> {
+    #[cfg(not(feature = "irtt"))]
+    if settings.advanced_settings.measurement_type == ReflectorProtocol::Irtt {
+        anyhow::bail!(
+            "IRTT measurement selected, but this binary was built without the `irtt` feature"
+        );
+    }
     let rt = tokio::runtime::Runtime::new()?;
 
     if settings.advanced_settings.dry_run {
@@ -299,6 +306,7 @@ fn run(settings: &Settings) -> anyhow::Result<()> {
     let (control_snapshot_tx, control_snapshot_rx) = flume::unbounded();
     let (error_tx, error_rx) = flume::unbounded::<anyhow::Error>();
     let (icmp_binding_tx, icmp_binding_rx) = flume::unbounded();
+    #[cfg(feature = "irtt")]
     let (irtt_binding_tx, irtt_binding_rx) = flume::unbounded();
     let (measurement_tx, measurement_rx) = flume::unbounded();
     let (reflector_tx, reflector_rx) = flume::unbounded();
@@ -318,6 +326,7 @@ fn run(settings: &Settings) -> anyhow::Result<()> {
     let controller = Controller::new(
         reflector_rx,
         icmp_binding_tx,
+        #[cfg(feature = "irtt")]
         irtt_binding_tx,
         reflectors,
         Arc::clone(&active_streams),
@@ -333,13 +342,20 @@ fn run(settings: &Settings) -> anyhow::Result<()> {
             icmp_binding_rx,
         )?
     };
-    let (_irtt_task, irtt_engine) = {
+    #[cfg(feature = "irtt")]
+    let (irtt_task, irtt_engine) = {
         let _guard = rt.enter();
-        IrttEngine::new(start_time, measurement_tx, irtt_binding_rx)?
+        IrttEngine::new(
+            start_time,
+            Duration::from_secs_f64(settings.advanced_settings.tick_interval),
+            measurement_tx,
+            irtt_binding_rx,
+        )?
     };
 
     spawn_task(&rt, &error_tx, icmp_engine.run());
-    spawn_task(&rt, &error_tx, irtt_engine.run());
+    #[cfg(feature = "irtt")]
+    spawn_task(&rt, &error_tx, irtt_engine.run(irtt_task));
 
     let dropped = Arc::new(AtomicU32::new(0));