docs(p2p/pubsub): rebroadcast webrtc message to libp2p peers

Author: binier

node/src/transition_frontier/transition_frontier_effects.rs

@@ -307,6 +307,7 @@ fn synced_effects<S: crate::Service>(
             best_tip: best_tip.block.clone(),
         });
     }
+    // rebroadcast block if received from webrtc network, otherwise noop.
     store.dispatch(P2pNetworkPubsubAction::WebRtcRebroadcast {
         message: GossipNetMessageV2::NewState(best_tip.block().clone()),
     });

p2p/src/channels/snark/p2p_channels_snark_reducer.rs

@@ -226,6 +226,7 @@ impl P2pChannelsSnarkState {
                 if is_local {
                     dispatcher.push(P2pNetworkPubsubAction::Broadcast { message });
                 } else {
+                    // rebroadcast snark if received from webrtc network, otherwise noop.
                     dispatcher.push(P2pNetworkPubsubAction::WebRtcRebroadcast { message });
                 }
                 Ok(())

p2p/src/channels/transaction/p2p_channels_transaction_reducer.rs

@@ -244,6 +244,7 @@ impl P2pChannelsTransactionState {
                 if is_local {
                     dispatcher.push(P2pNetworkPubsubAction::Broadcast { message });
                 } else {
+                    // rebroadcast block if received from webrtc network, otherwise noop.
                     dispatcher.push(P2pNetworkPubsubAction::WebRtcRebroadcast { message });
                 }
                 Ok(())

p2p/src/network/pubsub/p2p_network_pubsub_actions.rs

@@ -78,6 +78,13 @@ pub enum P2pNetworkPubsubAction {
     },
 
     /// Rebroadcast message received from WebRTC connection.
+    ///
+    /// Expected to be dispatched after the message has been processed,
+    /// in spite of whether it was received from libp2p or webrtc network.
+    ///
+    /// If received from libp2p network, or if we have already broadcasted
+    /// this message, the message will be in the `mcache` state,
+    /// in which case the action won't be enabled (will be filtered out).
     WebRtcRebroadcast {
         message: GossipNetMessageV2,
     },