Abstract persistent transmission rng (#903)

nomos-mix/core/Cargo.toml

@@ -12,8 +12,9 @@ rand = "0.8"
 serde = { version = "1.0", features = ["derive"] }
 nomos-mix-message = { path = "../message" }
 futures = "0.3"
-rand_chacha = "0.3"
 
 
 [dev-dependencies]
 tokio = { version = "1", features = ["rt-multi-thread"] }
+rand_chacha = "0.3"
+

nomos-mix/core/src/persistent_transmission.rs

@@ -1,7 +1,6 @@
 use futures::Stream;
 use nomos_mix_message::DROP_MESSAGE;
-use rand::{distributions::Uniform, prelude::Distribution, Rng, SeedableRng};
-use rand_chacha::ChaCha12Rng;
+use rand::{distributions::Uniform, prelude::Distribution, Rng, RngCore};
 use serde::{Deserialize, Serialize};
 use std::pin::{pin, Pin};
 use std::task::{Context, Poll};
@@ -27,31 +26,30 @@ impl Default for PersistentTransmissionSettings {
 }
 
 /// Transmit scheduled messages with a persistent rate as a stream.
-pub struct PersistentTransmissionStream<S>
+pub struct PersistentTransmissionStream<S, Rng>
 where
     S: Stream,
+    Rng: RngCore,
 {
     interval: Interval,
-    coin: Coin<ChaCha12Rng>,
+    coin: Coin<Rng>,
     stream: S,
 }
 
-impl<S> PersistentTransmissionStream<S>
+impl<S, Rng> PersistentTransmissionStream<S, Rng>
 where
     S: Stream,
+    Rng: RngCore,
 {
     pub fn new(
         settings: PersistentTransmissionSettings,
         stream: S,
-    ) -> PersistentTransmissionStream<S> {
+        rng: Rng,
+    ) -> PersistentTransmissionStream<S, Rng> {
         let interval = time::interval(Duration::from_secs_f64(
             1.0 / settings.max_emission_frequency,
         ));
-        let coin = Coin::<_>::new(
-            ChaCha12Rng::from_entropy(),
-            settings.drop_message_probability,
-        )
-        .unwrap();
+        let coin = Coin::<Rng>::new(rng, settings.drop_message_probability).unwrap();
         Self {
             interval,
             coin,
@@ -60,9 +58,10 @@ where
     }
 }
 
-impl<S> Stream for PersistentTransmissionStream<S>
+impl<S, Rng> Stream for PersistentTransmissionStream<S, Rng>
 where
     S: Stream<Item = Vec<u8>> + Unpin,
+    Rng: RngCore + Unpin,
 {
     type Item = Vec<u8>;
 
@@ -86,19 +85,28 @@ where
     }
 }
 
-pub trait PersistentTransmissionExt: Stream {
+pub trait PersistentTransmissionExt<Rng>: Stream
+where
+    Rng: RngCore,
+{
     fn persistent_transmission(
         self,
         settings: PersistentTransmissionSettings,
-    ) -> PersistentTransmissionStream<Self>
+        rng: Rng,
+    ) -> PersistentTransmissionStream<Self, Rng>
     where
         Self: Sized + Unpin,
     {
-        PersistentTransmissionStream::new(settings, self)
+        PersistentTransmissionStream::new(settings, self, rng)
     }
 }
 
-impl<S> PersistentTransmissionExt for S where S: Stream {}
+impl<S, Rng> PersistentTransmissionExt<Rng> for S
+where
+    S: Stream,
+    Rng: RngCore,
+{
+}
 
 struct Coin<R: Rng> {
     rng: R,
@@ -133,6 +141,8 @@ enum CoinError {
 mod tests {
     use super::*;
     use futures::StreamExt;
+    use rand::SeedableRng;
+    use rand_chacha::ChaCha8Rng;
     use tokio::sync::mpsc;
 
     macro_rules! assert_interval {
@@ -173,7 +183,8 @@ mod tests {
         let lower_bound = expected_emission_interval - torelance;
         let upper_bound = expected_emission_interval + torelance;
         // prepare stream
-        let mut persistent_transmission_stream = stream.persistent_transmission(settings);
+        let mut persistent_transmission_stream =
+            stream.persistent_transmission(settings, ChaCha8Rng::from_entropy());
         // Messages must be scheduled in non-blocking manner.
         schedule_sender.send(vec![1]).unwrap();
         schedule_sender.send(vec![2]).unwrap();

nomos-services/mix/Cargo.toml

@@ -15,6 +15,7 @@ nomos-mix-message = { path = "../../nomos-mix/message" }
 nomos-network = { path = "../network" }
 overwatch-rs = { git = "https://github.com/logos-co/Overwatch", rev = "2f70806" }
 rand = "0.8.5"
+rand_chacha = "0.3"
 serde = { version = "1.0", features = ["derive"] }
 tokio = { version = "1", features = ["macros", "sync"] }
 tokio-stream = "0.1"

nomos-services/mix/src/lib.rs

@@ -20,6 +20,8 @@ use overwatch_rs::services::{
     state::{NoOperator, NoState},
     ServiceCore, ServiceData, ServiceId,
 };
+use rand::SeedableRng;
+use rand_chacha::ChaCha12Rng;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::fmt::Debug;
 use tokio::sync::mpsc;
@@ -92,8 +94,10 @@ where
         // tier 1 persistent transmission
         let (persistent_sender, persistent_receiver) = mpsc::unbounded_channel();
         let mut persistent_transmission_messages =
-            UnboundedReceiverStream::new(persistent_receiver)
-                .persistent_transmission(mix_config.persistent_transmission);
+            UnboundedReceiverStream::new(persistent_receiver).persistent_transmission(
+                mix_config.persistent_transmission,
+                ChaCha12Rng::from_entropy(),
+            );
 
         // tier 2 blend
         let mut blend_messages = backend