Said module used by cover traffic stream

nym-client/src/client/cover_traffic_stream.rs

@@ -1,29 +1,35 @@
 use crate::client::mix_traffic::MixMessage;
+use crate::client::topology_control::TopologyInnerRef;
 use crate::client::LOOP_COVER_AVERAGE_DELAY;
 use futures::channel::mpsc;
-use log::{info, trace};
+use log::{info, trace, warn};
 use sphinx::route::Destination;
 use std::time::Duration;
 use topology::NymTopology;
 
-pub(crate) async fn start_loop_cover_traffic_stream<T>(
+pub(crate) async fn start_loop_cover_traffic_stream<T: NymTopology>(
     tx: mpsc::UnboundedSender<MixMessage>,
     our_info: Destination,
-    topology: T,
-) where
-    T: NymTopology,
-{
+    topology_ctrl_ref: TopologyInnerRef<T>,
+) {
     info!("Starting loop cover traffic stream");
     loop {
         trace!("next cover message!");
         let delay = mix_client::poisson::sample(LOOP_COVER_AVERAGE_DELAY);
         let delay_duration = Duration::from_secs_f64(delay);
         tokio::time::delay_for(delay_duration).await;
-        let cover_message = mix_client::packet::loop_cover_message(
-            our_info.address,
-            our_info.identifier,
-            &topology,
-        );
+
+        let read_lock = topology_ctrl_ref.read().await;
+        let topology = read_lock.topology.as_ref();
+        if topology.is_none() {
+            warn!("No valid topology detected - won't send any loop cover message this time");
+            continue;
+        }
+
+        let topology = topology.unwrap();
+
+        let cover_message =
+            mix_client::packet::loop_cover_message(our_info.address, our_info.identifier, topology);
 
         // if this one fails, there's no retrying because it means that either:
         // - we run out of memory