Remove async-trait from tendermint-machine, tributary-chain

coordinator/tributary/src/lib.rs

@@ -1,8 +1,6 @@
-use core::{marker::PhantomData, fmt::Debug};
+use core::{marker::PhantomData, fmt::Debug, future::Future};
 use std::{sync::Arc, io};
 
-use async_trait::async_trait;
-
 use zeroize::Zeroizing;
 
 use ciphersuite::{Ciphersuite, Ristretto};
@@ -131,20 +129,18 @@ pub trait ReadWrite: Sized {
   }
 }
 
-#[async_trait]
 pub trait P2p: 'static + Send + Sync + Clone + Debug {
   /// Broadcast a message to all other members of the Tributary with the specified genesis.
   ///
   /// The Tributary will re-broadcast consensus messages on a fixed interval to ensure they aren't
   /// prematurely dropped from the P2P layer. THe P2P layer SHOULD perform content-based
   /// deduplication to ensure a sane amount of load.
-  async fn broadcast(&self, genesis: [u8; 32], msg: Vec<u8>);
+  fn broadcast(&self, genesis: [u8; 32], msg: Vec<u8>) -> impl Send + Future<Output = ()>;
 }
 
-#[async_trait]
 impl<P: P2p> P2p for Arc<P> {
-  async fn broadcast(&self, genesis: [u8; 32], msg: Vec<u8>) {
-    (*self).broadcast(genesis, msg).await
+  fn broadcast(&self, genesis: [u8; 32], msg: Vec<u8>) -> impl Send + Future<Output = ()> {
+    P::broadcast(self, genesis, msg)
   }
 }
 

coordinator/tributary/src/tendermint/mod.rs

@@ -1,8 +1,6 @@
-use core::ops::Deref;
+use core::{ops::Deref, future::Future};
 use std::{sync::Arc, collections::HashMap};
 
-use async_trait::async_trait;
-
 use subtle::ConstantTimeEq;
 use zeroize::{Zeroize, Zeroizing};
 
@@ -74,50 +72,52 @@ impl Signer {
   }
 }
 
-#[async_trait]
 impl SignerTrait for Signer {
   type ValidatorId = [u8; 32];
   type Signature = [u8; 64];
 
   /// Returns the validator's current ID. Returns None if they aren't a current validator.
-  async fn validator_id(&self) -> Option<Self::ValidatorId> {
-    Some((Ristretto::generator() * self.key.deref()).to_bytes())
+  fn validator_id(&self) -> impl Send + Future<Output = Option<Self::ValidatorId>> {
+    async move { Some((Ristretto::generator() * self.key.deref()).to_bytes()) }
   }
 
   /// Sign a signature with the current validator's private key.
-  async fn sign(&self, msg: &[u8]) -> Self::Signature {
-    let mut nonce = Zeroizing::new(RecommendedTranscript::new(b"Tributary Chain Tendermint Nonce"));
-    nonce.append_message(b"genesis", self.genesis);
-    nonce.append_message(b"key", Zeroizing::new(self.key.deref().to_repr()).as_ref());
-    nonce.append_message(b"message", msg);
-    let mut nonce = nonce.challenge(b"nonce");
+  fn sign(&self, msg: &[u8]) -> impl Send + Future<Output = Self::Signature> {
+    async move {
+      let mut nonce =
+        Zeroizing::new(RecommendedTranscript::new(b"Tributary Chain Tendermint Nonce"));
+      nonce.append_message(b"genesis", self.genesis);
+      nonce.append_message(b"key", Zeroizing::new(self.key.deref().to_repr()).as_ref());
+      nonce.append_message(b"message", msg);
+      let mut nonce = nonce.challenge(b"nonce");
 
-    let mut nonce_arr = [0; 64];
-    nonce_arr.copy_from_slice(nonce.as_ref());
+      let mut nonce_arr = [0; 64];
+      nonce_arr.copy_from_slice(nonce.as_ref());
 
-    let nonce_ref: &mut [u8] = nonce.as_mut();
-    nonce_ref.zeroize();
-    let nonce_ref: &[u8] = nonce.as_ref();
-    assert_eq!(nonce_ref, [0; 64].as_ref());
+      let nonce_ref: &mut [u8] = nonce.as_mut();
+      nonce_ref.zeroize();
+      let nonce_ref: &[u8] = nonce.as_ref();
+      assert_eq!(nonce_ref, [0; 64].as_ref());
 
-    let nonce =
-      Zeroizing::new(<Ristretto as Ciphersuite>::F::from_bytes_mod_order_wide(&nonce_arr));
-    nonce_arr.zeroize();
+      let nonce =
+        Zeroizing::new(<Ristretto as Ciphersuite>::F::from_bytes_mod_order_wide(&nonce_arr));
+      nonce_arr.zeroize();
 
-    assert!(!bool::from(nonce.ct_eq(&<Ristretto as Ciphersuite>::F::ZERO)));
+      assert!(!bool::from(nonce.ct_eq(&<Ristretto as Ciphersuite>::F::ZERO)));
 
-    let challenge = challenge(
-      self.genesis,
-      (Ristretto::generator() * self.key.deref()).to_bytes(),
-      (Ristretto::generator() * nonce.deref()).to_bytes().as_ref(),
-      msg,
-    );
+      let challenge = challenge(
+        self.genesis,
+        (Ristretto::generator() * self.key.deref()).to_bytes(),
+        (Ristretto::generator() * nonce.deref()).to_bytes().as_ref(),
+        msg,
+      );
 
-    let sig = SchnorrSignature::<Ristretto>::sign(&self.key, nonce, challenge).serialize();
+      let sig = SchnorrSignature::<Ristretto>::sign(&self.key, nonce, challenge).serialize();
 
-    let mut res = [0; 64];
-    res.copy_from_slice(&sig);
-    res
+      let mut res = [0; 64];
+      res.copy_from_slice(&sig);
+      res
+    }
   }
 }
 
@@ -274,7 +274,6 @@ pub const BLOCK_PROCESSING_TIME: u32 = 999;
 pub const LATENCY_TIME: u32 = 1667;
 pub const TARGET_BLOCK_TIME: u32 = BLOCK_PROCESSING_TIME + (3 * LATENCY_TIME);
 
-#[async_trait]
 impl<D: Db, T: TransactionTrait, P: P2p> Network for TendermintNetwork<D, T, P> {
   type Db = D;
 
@@ -300,111 +299,126 @@ impl<D: Db, T: TransactionTrait, P: P2p> Network for TendermintNetwork<D, T, P>
     self.validators.clone()
   }
 
-  async fn broadcast(&mut self, msg: SignedMessageFor<Self>) {
-    let mut to_broadcast = vec![TENDERMINT_MESSAGE];
-    to_broadcast.extend(msg.encode());
-    self.p2p.broadcast(self.genesis, to_broadcast).await
-  }
-
-  async fn slash(&mut self, validator: Self::ValidatorId, slash_event: SlashEvent) {
-    log::error!(
-      "validator {} triggered a slash event on tributary {} (with evidence: {})",
-      hex::encode(validator),
-      hex::encode(self.genesis),
-      matches!(slash_event, SlashEvent::WithEvidence(_)),
-    );
-
-    let signer = self.signer();
-    let Some(tx) = (match slash_event {
-      SlashEvent::WithEvidence(evidence) => {
-        // create an unsigned evidence tx
-        Some(TendermintTx::SlashEvidence(evidence))
-      }
-      SlashEvent::Id(_reason, _block, _round) => {
-        // TODO: Increase locally observed slash points
-        None
-      }
-    }) else {
-      return;
-    };
-
-    // add tx to blockchain and broadcast to peers
-    let mut to_broadcast = vec![TRANSACTION_MESSAGE];
-    tx.write(&mut to_broadcast).unwrap();
-    if self.blockchain.write().await.add_transaction::<Self>(
-      true,
-      Transaction::Tendermint(tx),
-      &self.signature_scheme(),
-    ) == Ok(true)
-    {
-      self.p2p.broadcast(signer.genesis, to_broadcast).await;
+  fn broadcast(&mut self, msg: SignedMessageFor<Self>) -> impl Send + Future<Output = ()> {
+    async move {
+      let mut to_broadcast = vec![TENDERMINT_MESSAGE];
+      to_broadcast.extend(msg.encode());
+      self.p2p.broadcast(self.genesis, to_broadcast).await
     }
   }
 
-  async fn validate(&self, block: &Self::Block) -> Result<(), TendermintBlockError> {
-    let block =
-      Block::read::<&[u8]>(&mut block.0.as_ref()).map_err(|_| TendermintBlockError::Fatal)?;
-    self
-      .blockchain
-      .read()
-      .await
-      .verify_block::<Self>(&block, &self.signature_scheme(), false)
-      .map_err(|e| match e {
-        BlockError::NonLocalProvided(_) => TendermintBlockError::Temporal,
-        _ => {
-          log::warn!("Tributary Tendermint validate returning BlockError::Fatal due to {e:?}");
-          TendermintBlockError::Fatal
+  fn slash(
+    &mut self,
+    validator: Self::ValidatorId,
+    slash_event: SlashEvent,
+  ) -> impl Send + Future<Output = ()> {
+    async move {
+      log::error!(
+        "validator {} triggered a slash event on tributary {} (with evidence: {})",
+        hex::encode(validator),
+        hex::encode(self.genesis),
+        matches!(slash_event, SlashEvent::WithEvidence(_)),
+      );
+
+      let signer = self.signer();
+      let Some(tx) = (match slash_event {
+        SlashEvent::WithEvidence(evidence) => {
+          // create an unsigned evidence tx
+          Some(TendermintTx::SlashEvidence(evidence))
         }
-      })
+        SlashEvent::Id(_reason, _block, _round) => {
+          // TODO: Increase locally observed slash points
+          None
+        }
+      }) else {
+        return;
+      };
+
+      // add tx to blockchain and broadcast to peers
+      let mut to_broadcast = vec![TRANSACTION_MESSAGE];
+      tx.write(&mut to_broadcast).unwrap();
+      if self.blockchain.write().await.add_transaction::<Self>(
+        true,
+        Transaction::Tendermint(tx),
+        &self.signature_scheme(),
+      ) == Ok(true)
+      {
+        self.p2p.broadcast(signer.genesis, to_broadcast).await;
+      }
+    }
   }
 
-  async fn add_block(
+  fn validate(
+    &self,
+    block: &Self::Block,
+  ) -> impl Send + Future<Output = Result<(), TendermintBlockError>> {
+    async move {
+      let block =
+        Block::read::<&[u8]>(&mut block.0.as_ref()).map_err(|_| TendermintBlockError::Fatal)?;
+      self
+        .blockchain
+        .read()
+        .await
+        .verify_block::<Self>(&block, &self.signature_scheme(), false)
+        .map_err(|e| match e {
+          BlockError::NonLocalProvided(_) => TendermintBlockError::Temporal,
+          _ => {
+            log::warn!("Tributary Tendermint validate returning BlockError::Fatal due to {e:?}");
+            TendermintBlockError::Fatal
+          }
+        })
+    }
+  }
+
+  fn add_block(
     &mut self,
     serialized_block: Self::Block,
     commit: Commit<Self::SignatureScheme>,
-  ) -> Option<Self::Block> {
-    let invalid_block = || {
-      // There's a fatal flaw in the code, it's behind a hard fork, or the validators turned
-      // malicious
-      // All justify a halt to then achieve social consensus from
-      // TODO: Under multiple validator sets, a small validator set turning malicious knocks
-      // off the entire network. That's an unacceptable DoS.
-      panic!("validators added invalid block to tributary {}", hex::encode(self.genesis));
-    };
+  ) -> impl Send + Future<Output = Option<Self::Block>> {
+    async move {
+      let invalid_block = || {
+        // There's a fatal flaw in the code, it's behind a hard fork, or the validators turned
+        // malicious
+        // All justify a halt to then achieve social consensus from
+        // TODO: Under multiple validator sets, a small validator set turning malicious knocks
+        // off the entire network. That's an unacceptable DoS.
+        panic!("validators added invalid block to tributary {}", hex::encode(self.genesis));
+      };
 
-    // Tendermint should only produce valid commits
-    assert!(self.verify_commit(serialized_block.id(), &commit));
+      // Tendermint should only produce valid commits
+      assert!(self.verify_commit(serialized_block.id(), &commit));
 
-    let Ok(block) = Block::read::<&[u8]>(&mut serialized_block.0.as_ref()) else {
-      return invalid_block();
-    };
+      let Ok(block) = Block::read::<&[u8]>(&mut serialized_block.0.as_ref()) else {
+        return invalid_block();
+      };
 
-    let encoded_commit = commit.encode();
-    loop {
-      let block_res = self.blockchain.write().await.add_block::<Self>(
-        &block,
-        encoded_commit.clone(),
-        &self.signature_scheme(),
-      );
-      match block_res {
-        Ok(()) => {
-          // If we successfully added this block, break
-          break;
+      let encoded_commit = commit.encode();
+      loop {
+        let block_res = self.blockchain.write().await.add_block::<Self>(
+          &block,
+          encoded_commit.clone(),
+          &self.signature_scheme(),
+        );
+        match block_res {
+          Ok(()) => {
+            // If we successfully added this block, break
+            break;
+          }
+          Err(BlockError::NonLocalProvided(hash)) => {
+            log::error!(
+              "missing provided transaction {} which other validators on tributary {} had",
+              hex::encode(hash),
+              hex::encode(self.genesis)
+            );
+            tokio::time::sleep(core::time::Duration::from_secs(5)).await;
+          }
+          _ => return invalid_block(),
         }
-        Err(BlockError::NonLocalProvided(hash)) => {
-          log::error!(
-            "missing provided transaction {} which other validators on tributary {} had",
-            hex::encode(hash),
-            hex::encode(self.genesis)
-          );
-          tokio::time::sleep(core::time::Duration::from_secs(5)).await;
-        }
-        _ => return invalid_block(),
       }
-    }
 
-    Some(TendermintBlock(
-      self.blockchain.write().await.build_block::<Self>(&self.signature_scheme()).serialize(),
-    ))
+      Some(TendermintBlock(
+        self.blockchain.write().await.build_block::<Self>(&self.signature_scheme()).serialize(),
+      ))
+    }
   }
 }

coordinator/tributary/src/tests/p2p.rs

@@ -1,11 +1,12 @@
+use core::future::Future;
+
 pub use crate::P2p;
 
 #[derive(Clone, Debug)]
 pub struct DummyP2p;
 
-#[async_trait::async_trait]
 impl P2p for DummyP2p {
-  async fn broadcast(&self, _: [u8; 32], _: Vec<u8>) {
-    unimplemented!()
+  fn broadcast(&self, _: [u8; 32], _: Vec<u8>) -> impl Send + Future<Output = ()> {
+    async move { unimplemented!() }
   }
 }

coordinator/tributary/src/tests/tendermint.rs

@@ -1,4 +1,7 @@
+use core::future::Future;
+
 use tendermint::ext::Network;
+
 use crate::{
   P2p, TendermintTx,
   tendermint::{TARGET_BLOCK_TIME, TendermintNetwork},
@@ -11,10 +14,9 @@ fn assert_target_block_time() {
   #[derive(Clone, Debug)]
   pub struct DummyP2p;
 
-  #[async_trait::async_trait]
   impl P2p for DummyP2p {
-    async fn broadcast(&self, _: [u8; 32], _: Vec<u8>) {
-      unimplemented!()
+    fn broadcast(&self, _: [u8; 32], _: Vec<u8>) -> impl Send + Future<Output = ()> {
+      async move { unimplemented!() }
     }
   }