Mix: time abstract from streams (#906)

* Extract temporal async stream

* Make stuff public

* Extract persistent transmission scheduler

* Fix tests

* Push temporal scheduler one layer up

* fix compile errors

* return Poll::Pending instead of Poll::Ready(None) when queue is empty

---------

Co-authored-by: Youngjoon Lee <5462944+youngjoon-lee@users.noreply.github.com>

nomos-mix/core/src/message_blend/mod.rs

@@ -8,7 +8,7 @@ use rand::RngCore;
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
-pub use temporal::TemporalProcessorSettings;
+pub use temporal::TemporalSchedulerSettings;
 
 use crate::membership::Membership;
 use crate::message_blend::crypto::CryptographicProcessor;
@@ -28,13 +28,13 @@ where
     M::PrivateKey: Serialize + DeserializeOwned,
 {
     pub cryptographic_processor: CryptographicProcessorSettings<M::PrivateKey>,
-    pub temporal_processor: TemporalProcessorSettings,
+    pub temporal_processor: TemporalSchedulerSettings,
 }
 
 /// [`MessageBlendStream`] handles the entire mixing tiers process
 /// - Unwraps incoming messages received from network using [`CryptographicProcessor`]
 /// - Pushes unwrapped messages to [`TemporalProcessor`]
-pub struct MessageBlendStream<S, Rng, M>
+pub struct MessageBlendStream<S, Rng, M, Scheduler>
 where
     M: MixMessage,
 {
@@ -43,22 +43,24 @@ where
     temporal_sender: UnboundedSender<MixOutgoingMessage>,
     cryptographic_processor: CryptographicProcessor<Rng, M>,
     _rng: PhantomData<Rng>,
+    _scheduler: PhantomData<Scheduler>,
 }
 
-impl<S, Rng, M> MessageBlendStream<S, Rng, M>
+impl<S, Rng, M, Scheduler> MessageBlendStream<S, Rng, M, Scheduler>
 where
     S: Stream<Item = Vec<u8>>,
     Rng: RngCore + Unpin + Send + 'static,
     M: MixMessage,
     M::PrivateKey: Serialize + DeserializeOwned,
     M::PublicKey: Clone + PartialEq,
+    Scheduler: Stream<Item = ()> + Unpin + Send + 'static,
 {
     pub fn new(
         input_stream: S,
         settings: MessageBlendSettings<M>,
         membership: Membership<M>,
+        scheduler: Scheduler,
         cryptographic_processor_rng: Rng,
-        temporal_processor_rng: Rng,
     ) -> Self {
         let cryptographic_processor = CryptographicProcessor::new(
             settings.cryptographic_processor,
@@ -67,7 +69,7 @@ where
         );
         let (temporal_sender, temporal_receiver) = mpsc::unbounded_channel();
         let output_stream = UnboundedReceiverStream::new(temporal_receiver)
-            .temporal_stream(settings.temporal_processor, temporal_processor_rng)
+            .temporal_stream(scheduler)
             .boxed();
         Self {
             input_stream,
@@ -75,6 +77,7 @@ where
             temporal_sender,
             cryptographic_processor,
             _rng: Default::default(),
+            _scheduler: Default::default(),
         }
     }
 
@@ -100,13 +103,14 @@ where
     }
 }
 
-impl<S, Rng, M> Stream for MessageBlendStream<S, Rng, M>
+impl<S, Rng, M, Scheduler> Stream for MessageBlendStream<S, Rng, M, Scheduler>
 where
     S: Stream<Item = Vec<u8>> + Unpin,
     Rng: RngCore + Unpin + Send + 'static,
     M: MixMessage + Unpin,
     M::PrivateKey: Serialize + DeserializeOwned + Unpin,
     M::PublicKey: Clone + PartialEq + Unpin,
+    Scheduler: Stream<Item = ()> + Unpin + Send + 'static,
 {
     type Item = MixOutgoingMessage;
 
@@ -118,20 +122,21 @@ where
     }
 }
 
-pub trait MessageBlendExt<Rng, M>: Stream<Item = Vec<u8>>
+pub trait MessageBlendExt<Rng, M, Scheduler>: Stream<Item = Vec<u8>>
 where
     Rng: RngCore + Send + Unpin + 'static,
     M: MixMessage,
     M::PrivateKey: Serialize + DeserializeOwned,
     M::PublicKey: Clone + PartialEq,
+    Scheduler: Stream<Item = ()> + Unpin + Send + 'static,
 {
     fn blend(
         self,
         message_blend_settings: MessageBlendSettings<M>,
         membership: Membership<M>,
+        scheduler: Scheduler,
         cryptographic_processor_rng: Rng,
-        temporal_processor_rng: Rng,
+    ) -> MessageBlendStream<Self, Rng, M, Scheduler>
-    ) -> MessageBlendStream<Self, Rng, M>
     where
         Self: Sized + Unpin,
     {
@@ -139,18 +144,19 @@ where
             self,
             message_blend_settings,
             membership,
+            scheduler,
             cryptographic_processor_rng,
-            temporal_processor_rng,
         )
     }
 }
 
-impl<T, Rng, M> MessageBlendExt<Rng, M> for T
+impl<T, Rng, M, S> MessageBlendExt<Rng, M, S> for T
 where
     T: Stream<Item = Vec<u8>>,
     Rng: RngCore + Unpin + Send + 'static,
     M: MixMessage,
     M::PrivateKey: Clone + Serialize + DeserializeOwned + PartialEq,
     M::PublicKey: Clone + Serialize + DeserializeOwned + PartialEq,
+    S: Stream<Item = ()> + Unpin + Send + 'static,
 {
 }

nomos-mix/core/src/message_blend/temporal.rs

@@ -10,14 +10,8 @@ use rand::{Rng, RngCore};
 use serde::{Deserialize, Serialize};
 use tokio::time;
 
-/// [`TemporalProcessor`] delays messages randomly to hide timing correlation
+pub struct TemporalScheduler<Rng> {
-/// between incoming and outgoing messages from a node.
+    settings: TemporalSchedulerSettings,
-///
-/// See the [`Stream`] implementation below for more details on how it works.
-pub(crate) struct TemporalProcessor<M, Rng> {
-    settings: TemporalProcessorSettings,
-    // All scheduled messages
-    queue: VecDeque<M>,
     /// Interval in seconds for running the lottery to release a message
     lottery_interval: time::Interval,
     /// To wait a few seconds after running the lottery before releasing the message.
@@ -27,17 +21,11 @@ pub(crate) struct TemporalProcessor<M, Rng> {
     rng: Rng,
 }
 
-#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
+impl<Rng> TemporalScheduler<Rng> {
-pub struct TemporalProcessorSettings {
+    pub fn new(settings: TemporalSchedulerSettings, rng: Rng) -> Self {
-    pub max_delay_seconds: u64,
-}
-
-impl<M, Rng> TemporalProcessor<M, Rng> {
-    pub(crate) fn new(settings: TemporalProcessorSettings, rng: Rng) -> Self {
         let lottery_interval = Self::lottery_interval(settings.max_delay_seconds);
         Self {
             settings,
-            queue: VecDeque::new(),
             lottery_interval,
             release_timer: None,
             rng,
@@ -58,12 +46,9 @@ impl<M, Rng> TemporalProcessor<M, Rng> {
     fn lottery_interval_seconds(max_delay_seconds: u64) -> u64 {
         max_delay_seconds / 2
     }
-    /// Schedule a message to be released later.
-    pub(crate) fn push_message(&mut self, message: M) {
-        self.queue.push_back(message);
-    }
 }
-impl<M, Rng> TemporalProcessor<M, Rng>
+
+impl<Rng> TemporalScheduler<Rng>
 where
     Rng: RngCore,
 {
@@ -75,12 +60,11 @@ where
     }
 }
 
-impl<M, Rng> Stream for TemporalProcessor<M, Rng>
+impl<Rng> Stream for TemporalScheduler<Rng>
 where
-    M: Unpin,
     Rng: RngCore + Unpin,
 {
-    type Item = M;
+    type Item = ();
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         // Check whether it's time to run a new lottery to determine the delay.
@@ -94,33 +78,74 @@ where
         if let Some(timer) = self.release_timer.as_mut() {
             if timer.as_mut().poll(cx).is_ready() {
                 self.release_timer.take(); // Reset timer after it's done
-                if let Some(msg) = self.queue.pop_front() {
+                return Poll::Ready(Some(()));
-                    // Release the 1st message in the queue if it exists.
-                    return Poll::Ready(Some(msg));
             }
         }
-        }
-
         Poll::Pending
     }
 }
 
-pub struct TemporalStream<S, Rng>
+/// [`TemporalProcessor`] delays messages randomly to hide timing correlation
-where
+/// between incoming and outgoing messages from a node.
-    S: Stream,
+///
-    Rng: RngCore,
+/// See the [`Stream`] implementation below for more details on how it works.
-{
+pub struct TemporalProcessor<M, S> {
-    processor: TemporalProcessor<S::Item, Rng>,
+    // All scheduled messages
-    wrapped_stream: S,
+    queue: VecDeque<M>,
+    scheduler: S,
 }
 
-impl<S, Rng> Stream for TemporalStream<S, Rng>
+#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
+pub struct TemporalSchedulerSettings {
+    pub max_delay_seconds: u64,
+}
+
+impl<M, S> TemporalProcessor<M, S> {
+    pub(crate) fn new(scheduler: S) -> Self {
+        Self {
+            queue: VecDeque::new(),
+            scheduler,
+        }
+    }
+    /// Schedule a message to be released later.
+    pub(crate) fn push_message(&mut self, message: M) {
+        self.queue.push_back(message);
+    }
+}
+
+impl<M, S> Stream for TemporalProcessor<M, S>
 where
-    S: Stream + Unpin,
+    M: Unpin,
-    S::Item: Unpin,
+    S: Stream<Item = ()> + Unpin,
-    Rng: RngCore + Unpin,
 {
-    type Item = S::Item;
+    type Item = M;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        if self.scheduler.poll_next_unpin(cx).is_ready() {
+            if let Some(msg) = self.queue.pop_front() {
+                return Poll::Ready(Some(msg));
+            }
+        };
+        Poll::Pending
+    }
+}
+
+pub struct TemporalStream<WrappedStream, Scheduler>
+where
+    WrappedStream: Stream,
+    Scheduler: Stream<Item = ()>,
+{
+    processor: TemporalProcessor<WrappedStream::Item, Scheduler>,
+    wrapped_stream: WrappedStream,
+}
+
+impl<WrappedStream, Scheduler> Stream for TemporalStream<WrappedStream, Scheduler>
+where
+    WrappedStream: Stream + Unpin,
+    WrappedStream::Item: Unpin,
+    Scheduler: Stream<Item = ()> + Unpin,
+{
+    type Item = WrappedStream::Item;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         if let Poll::Ready(Some(item)) = self.wrapped_stream.poll_next_unpin(cx) {
@@ -129,28 +154,24 @@ where
         self.processor.poll_next_unpin(cx)
     }
 }
-pub trait TemporalProcessorExt<Rng>: Stream
+pub trait TemporalProcessorExt<Scheduler>: Stream
 where
-    Rng: RngCore,
+    Scheduler: Stream<Item = ()>,
 {
-    fn temporal_stream(
+    fn temporal_stream(self, scheduler: Scheduler) -> TemporalStream<Self, Scheduler>
-        self,
-        settings: TemporalProcessorSettings,
-        rng: Rng,
-    ) -> TemporalStream<Self, Rng>
     where
         Self: Sized,
     {
         TemporalStream {
-            processor: TemporalProcessor::new(settings, rng),
+            processor: TemporalProcessor::<Self::Item, Scheduler>::new(scheduler),
             wrapped_stream: self,
         }
     }
 }
 
-impl<T, Rng> TemporalProcessorExt<Rng> for T
+impl<T, S> TemporalProcessorExt<S> for T
 where
     T: Stream,
-    Rng: RngCore,
+    S: Stream<Item = ()>,
 {
 }

nomos-mix/core/src/persistent_transmission.rs

@@ -1,4 +1,4 @@
-use futures::Stream;
+use futures::{Stream, StreamExt};
 use nomos_mix_message::MixMessage;
 use rand::{distributions::Uniform, prelude::Distribution, Rng, RngCore};
 use serde::de::DeserializeOwned;
@@ -6,9 +6,6 @@ use serde::{Deserialize, Serialize};
 use std::marker::PhantomData;
 use std::pin::{pin, Pin};
 use std::task::{Context, Poll};
-use std::time::Duration;
-use tokio::time;
-use tokio::time::Interval;
 
 #[derive(Clone, Copy, Debug, Serialize, Deserialize)]
 pub struct PersistentTransmissionSettings {
@@ -28,57 +25,57 @@ impl Default for PersistentTransmissionSettings {
 }
 
 /// Transmit scheduled messages with a persistent rate as a stream.
-pub struct PersistentTransmissionStream<S, Rng, M>
+pub struct PersistentTransmissionStream<S, Rng, M, Scheduler>
 where
     S: Stream,
     Rng: RngCore,
 {
-    interval: Interval,
     coin: Coin<Rng>,
     stream: S,
+    scheduler: Scheduler,
     _mix_message: PhantomData<M>,
 }
 
-impl<S, Rng, M> PersistentTransmissionStream<S, Rng, M>
+impl<S, Rng, M, Scheduler> PersistentTransmissionStream<S, Rng, M, Scheduler>
 where
     S: Stream,
     Rng: RngCore,
     M: MixMessage,
+    Scheduler: Stream<Item = ()>,
 {
     pub fn new(
         settings: PersistentTransmissionSettings,
         stream: S,
+        scheduler: Scheduler,
         rng: Rng,
-    ) -> PersistentTransmissionStream<S, Rng, M> {
+    ) -> PersistentTransmissionStream<S, Rng, M, Scheduler> {
-        let interval = time::interval(Duration::from_secs_f64(
-            1.0 / settings.max_emission_frequency,
-        ));
         let coin = Coin::<Rng>::new(rng, settings.drop_message_probability).unwrap();
         Self {
-            interval,
             coin,
             stream,
+            scheduler,
             _mix_message: Default::default(),
         }
     }
 }
 
-impl<S, Rng, M> Stream for PersistentTransmissionStream<S, Rng, M>
+impl<S, Rng, M, Scheduler> Stream for PersistentTransmissionStream<S, Rng, M, Scheduler>
 where
     S: Stream<Item = Vec<u8>> + Unpin,
     Rng: RngCore + Unpin,
     M: MixMessage + Unpin,
+    Scheduler: Stream<Item = ()> + Unpin,
 {
     type Item = Vec<u8>;
 
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         let Self {
-            ref mut interval,
+            ref mut scheduler,
             ref mut stream,
             ref mut coin,
             ..
         } = self.get_mut();
-        if pin!(interval).poll_tick(cx).is_pending() {
+        if pin!(scheduler).poll_next_unpin(cx).is_pending() {
             return Poll::Pending;
         }
         if let Poll::Ready(Some(item)) = pin!(stream).poll_next(cx) {
@@ -91,29 +88,32 @@ where
     }
 }
 
-pub trait PersistentTransmissionExt<Rng, M>: Stream
+pub trait PersistentTransmissionExt<Rng, M, Scheduler>: Stream
 where
     Rng: RngCore,
     M: MixMessage,
+    Scheduler: Stream<Item = ()>,
 {
     fn persistent_transmission(
         self,
         settings: PersistentTransmissionSettings,
         rng: Rng,
-    ) -> PersistentTransmissionStream<Self, Rng, M>
+        scheduler: Scheduler,
+    ) -> PersistentTransmissionStream<Self, Rng, M, Scheduler>
     where
         Self: Sized + Unpin,
     {
-        PersistentTransmissionStream::new(settings, self, rng)
+        PersistentTransmissionStream::new(settings, self, scheduler, rng)
     }
 }
 
-impl<S, Rng, M> PersistentTransmissionExt<Rng, M> for S
+impl<S, Rng, M, Scheduler> PersistentTransmissionExt<Rng, M, Scheduler> for S
 where
     S: Stream,
     Rng: RngCore,
     M: MixMessage,
     M::PublicKey: Clone + Serialize + DeserializeOwned,
+    Scheduler: Stream<Item = ()>,
 {
 }
 
@@ -153,7 +153,10 @@ mod tests {
     use nomos_mix_message::mock::MockMixMessage;
     use rand::SeedableRng;
     use rand_chacha::ChaCha8Rng;
+    use std::time::Duration;
     use tokio::sync::mpsc;
+    use tokio::time;
+    use tokio_stream::wrappers::IntervalStream;
 
     macro_rules! assert_interval {
         ($last_time:expr, $lower_bound:expr, $upper_bound:expr) => {
@@ -193,8 +196,16 @@ mod tests {
         let lower_bound = expected_emission_interval - torelance;
         let upper_bound = expected_emission_interval + torelance;
         // prepare stream
-        let mut persistent_transmission_stream: PersistentTransmissionStream<_, _, MockMixMessage> =
+        let mut persistent_transmission_stream: PersistentTransmissionStream<
-            stream.persistent_transmission(settings, ChaCha8Rng::from_entropy());
+            _,
+            _,
+            MockMixMessage,
+            _,
+        > = stream.persistent_transmission(
+            settings,
+            ChaCha8Rng::from_entropy(),
+            IntervalStream::new(time::interval(expected_emission_interval)).map(|_| ()),
+        );
         // Messages must be scheduled in non-blocking manner.
         schedule_sender.send(vec![1]).unwrap();
         schedule_sender.send(vec![2]).unwrap();

nomos-services/data-availability/tests/src/common.rs

@@ -3,7 +3,7 @@ use cryptarchia_consensus::LeaderConfig;
 use nomos_da_network_service::backends::libp2p::common::DaNetworkBackendSettings;
 use nomos_mix::membership::Node;
 use nomos_mix::message_blend::{
-    CryptographicProcessorSettings, MessageBlendSettings, TemporalProcessorSettings,
+    CryptographicProcessorSettings, MessageBlendSettings, TemporalSchedulerSettings,
 };
 use nomos_mix_message::mock::MockMixMessage;
 use nomos_mix_message::MixMessage;
@@ -226,7 +226,7 @@ pub fn new_node(
                         private_key: mix_config.private_key.to_bytes(),
                         num_mix_layers: 1,
                     },
-                    temporal_processor: TemporalProcessorSettings {
+                    temporal_processor: TemporalSchedulerSettings {
                         max_delay_seconds: 2,
                     },
                 },

nomos-services/mix/src/lib.rs

@@ -8,6 +8,7 @@ use network::NetworkAdapter;
 use nomos_core::wire;
 use nomos_mix::membership::{Membership, Node};
 use nomos_mix::message_blend::crypto::CryptographicProcessor;
+use nomos_mix::message_blend::temporal::TemporalScheduler;
 use nomos_mix::message_blend::{MessageBlendExt, MessageBlendSettings};
 use nomos_mix::persistent_transmission::{
     PersistentTransmissionExt, PersistentTransmissionSettings, PersistentTransmissionStream,
@@ -26,8 +27,10 @@ use rand::SeedableRng;
 use rand_chacha::ChaCha12Rng;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 use std::fmt::Debug;
+use std::time::Duration;
 use tokio::sync::mpsc;
-use tokio_stream::wrappers::UnboundedReceiverStream;
+use tokio::time;
+use tokio_stream::wrappers::{IntervalStream, UnboundedReceiverStream};
 
 /// A mix service that sends messages to the mix network
 /// and broadcasts fully unwrapped messages through the [`NetworkService`].
@@ -108,16 +111,25 @@ where
             _,
             _,
             MockMixMessage,
+            _,
         > = UnboundedReceiverStream::new(persistent_receiver).persistent_transmission(
             mix_config.persistent_transmission,
             ChaCha12Rng::from_entropy(),
+            IntervalStream::new(time::interval(Duration::from_secs_f64(
+                1.0 / mix_config.persistent_transmission.max_emission_frequency,
+            )))
+            .map(|_| ()),
         );
 
         // tier 2 blend
+        let temporal_scheduler = TemporalScheduler::new(
+            mix_config.message_blend.temporal_processor,
+            ChaCha12Rng::from_entropy(),
+        );
         let mut blend_messages = backend.listen_to_incoming_messages().blend(
             mix_config.message_blend,
             membership.clone(),
-            ChaCha12Rng::from_entropy(),
+            temporal_scheduler,
             ChaCha12Rng::from_entropy(),
         );
 

tests/src/nodes/executor.rs

@@ -23,7 +23,7 @@ use nomos_da_verifier::DaVerifierServiceSettings;
 use nomos_executor::api::backend::AxumBackendSettings;
 use nomos_executor::config::Config;
 use nomos_mix::message_blend::{
-    CryptographicProcessorSettings, MessageBlendSettings, TemporalProcessorSettings,
+    CryptographicProcessorSettings, MessageBlendSettings, TemporalSchedulerSettings,
 };
 use nomos_network::{backends::libp2p::Libp2pConfig, NetworkConfig};
 use nomos_node::api::paths::{CL_METRICS, DA_GET_RANGE};
@@ -162,7 +162,7 @@ pub fn create_executor_config(config: GeneralConfig) -> Config {
                     private_key: config.mix_config.private_key.to_bytes(),
                     num_mix_layers: 1,
                 },
-                temporal_processor: TemporalProcessorSettings {
+                temporal_processor: TemporalSchedulerSettings {
                     max_delay_seconds: 2,
                 },
             },

tests/src/nodes/validator.rs

@@ -15,7 +15,7 @@ use nomos_da_verifier::storage::adapters::rocksdb::RocksAdapterSettings as Verif
 use nomos_da_verifier::{backend::kzgrs::KzgrsDaVerifierSettings, DaVerifierServiceSettings};
 use nomos_mempool::MempoolMetrics;
 use nomos_mix::message_blend::{
-    CryptographicProcessorSettings, MessageBlendSettings, TemporalProcessorSettings,
+    CryptographicProcessorSettings, MessageBlendSettings, TemporalSchedulerSettings,
 };
 use nomos_network::{backends::libp2p::Libp2pConfig, NetworkConfig};
 use nomos_node::api::paths::{
@@ -248,7 +248,7 @@ pub fn create_validator_config(config: GeneralConfig) -> Config {
                     private_key: config.mix_config.private_key.to_bytes(),
                     num_mix_layers: 1,
                 },
-                temporal_processor: TemporalProcessorSettings {
+                temporal_processor: TemporalSchedulerSettings {
                     max_delay_seconds: 2,
                 },
             },