Revert coordinator/tributary to fd4f247917

\#560 is causing notable CI failures, with its logs including slashes at 10x
the prior rate.

coordinator/tributary/src/tendermint/mod.rs

@@ -1,5 +1,8 @@
 use core::ops::Deref;
-use std::{sync::Arc, collections::HashMap};
+use std::{
+  sync::Arc,
+  collections::{VecDeque, HashMap},
+};
 
 use async_trait::async_trait;
 
@@ -267,6 +270,8 @@ pub struct TendermintNetwork<D: Db, T: TransactionTrait, P: P2p> {
   pub(crate) validators: Arc<Validators>,
   pub(crate) blockchain: Arc<RwLock<Blockchain<D, T>>>,
 
+  pub(crate) to_rebroadcast: Arc<RwLock<VecDeque<Vec<u8>>>>,
+
   pub(crate) p2p: P,
 }
 
@@ -303,6 +308,26 @@ impl<D: Db, T: TransactionTrait, P: P2p> Network for TendermintNetwork<D, T, P>
   async fn broadcast(&mut self, msg: SignedMessageFor<Self>) {
     let mut to_broadcast = vec![TENDERMINT_MESSAGE];
     to_broadcast.extend(msg.encode());
+
+    // Since we're broadcasting a Tendermint message, set it to be re-broadcasted every second
+    // until the block it's trying to build is complete
+    // If the P2P layer drops a message before all nodes obtained access, or a node had an
+    // intermittent failure, this will ensure reconcilliation
+    // This is atrocious if there's no content-based deduplication protocol for messages actively
+    // being gossiped
+    // LibP2p, as used by Serai, is configured to content-based deduplicate
+    {
+      let mut to_rebroadcast_lock = self.to_rebroadcast.write().await;
+      to_rebroadcast_lock.push_back(to_broadcast.clone());
+      // We should have, ideally, 3 * validators messages within a round
+      // Therefore, this should keep the most recent 2-rounds
+      // TODO: This isn't perfect. Each participant should just rebroadcast their latest round of
+      // messages
+      while to_rebroadcast_lock.len() > (6 * self.validators.weights.len()) {
+        to_rebroadcast_lock.pop_front();
+      }
+    }
+
     self.p2p.broadcast(self.genesis, to_broadcast).await
   }
 
@@ -341,7 +366,7 @@ impl<D: Db, T: TransactionTrait, P: P2p> Network for TendermintNetwork<D, T, P>
     }
   }
 
-  async fn validate(&self, block: &Self::Block) -> Result<(), TendermintBlockError> {
+  async fn validate(&mut self, block: &Self::Block) -> Result<(), TendermintBlockError> {
     let block =
       Block::read::<&[u8]>(&mut block.0.as_ref()).map_err(|_| TendermintBlockError::Fatal)?;
     self
@@ -403,6 +428,9 @@ impl<D: Db, T: TransactionTrait, P: P2p> Network for TendermintNetwork<D, T, P>
       }
     }
 
+    // Since we've added a valid block, clear to_rebroadcast
+    *self.to_rebroadcast.write().await = VecDeque::new();
+
     Some(TendermintBlock(
       self.blockchain.write().await.build_block::<Self>(&self.signature_scheme()).serialize(),
     ))