1 files changed, 47 insertions, 0 deletions
diff --git a/src/modules/delay.rs b/src/modules/delay.rs
new file mode 100644
index 0000000..ab46a90
--- /dev/null
+++ b/src/modules/delay.rs
@@ -0,0 +1,47 @@
+use super::{Node, NodeContext, NodeKind, NodeRequest, NodeResponse};
+use crate::{config::DynNode, error::ServiceError};
+use anyhow::Result;
+use rand_distr::Distribution;
+use serde::Deserialize;
+use serde_yml::Value;
+use std::{future::Future, pin::Pin, sync::Arc, time::Duration};
+use tokio::time::sleep;
+
+pub struct DelayKind;
+
+#[derive(Deserialize)]
+struct Delay {
+    duration: u64,
+    stdev: u64,
+    next: DynNode,
+}
+
+impl NodeKind for DelayKind {
+    fn name(&self) -> &'static str {
+        "delay"
+    }
+    fn instanciate(&self, config: Value) -> Result<Arc<dyn Node>> {
+        Ok(Arc::new(serde_yml::from_value::<Delay>(config)?))
+    }
+}
+impl Node for Delay {
+    fn handle<'a>(
+        &'a self,
+        context: &'a mut NodeContext,
+        request: NodeRequest,
+    ) -> Pin<Box<dyn Future<Output = Result<NodeResponse, ServiceError>> + Send + Sync + 'a>> {
+        Box::pin(async move {
+            sleep(Duration::from_millis(if self.stdev == 0 {
+                self.duration
+            } else {
+                self.duration.saturating_add_signed(
+                    rand_distr::Normal::new(0., self.stdev as f32)
+                        .unwrap()
+                        .sample(&mut rand::rng()) as i64,
+                )
+            }))
+            .await;
+            self.next.handle(context, request).await
+        })
+    }
+}