Have the TransactionPublisher build a TxLegacy from Transaction

Cargo.lock

@@ -8334,6 +8334,7 @@ dependencies = [
  "alloy-rpc-client",
  "alloy-rpc-types-eth",
  "alloy-simple-request-transport",
+ "alloy-transport",
  "borsh",
  "ciphersuite",
  "const-hex",

processor/ethereum/Cargo.toml

@@ -35,6 +35,7 @@ alloy-rlp  = { version = "0.3", default-features = false }
 alloy-consensus = { version = "0.3", default-features = false }
 
 alloy-rpc-types-eth = { version = "0.3", default-features = false }
+alloy-transport = { version = "0.3", default-features = false }
 alloy-simple-request-transport = { path = "../../networks/ethereum/alloy-simple-request-transport", default-features = false }
 alloy-rpc-client = { version = "0.3", default-features = false }
 alloy-provider = { version = "0.3", default-features = false }

processor/ethereum/src/main.rs

@@ -30,14 +30,13 @@ use publisher::TransactionPublisher;
 #[tokio::main]
 async fn main() {
   let db = bin::init();
-  let feed = {
-    let provider = Arc::new(RootProvider::new(
-      ClientBuilder::default().transport(SimpleRequest::new(bin::url()), true),
-    ));
-    Rpc { provider }
-  };
+
+  let provider = Arc::new(RootProvider::new(
+    ClientBuilder::default().transport(SimpleRequest::new(bin::url()), true),
+  ));
+
   let chain_id = loop {
-    match feed.provider.get_chain_id().await {
+    match provider.get_chain_id().await {
       Ok(chain_id) => break U256::try_from(chain_id).unwrap(),
       Err(e) => {
         log::error!("couldn't connect to the Ethereum node for the chain ID: {e:?}");
@@ -48,9 +47,9 @@ async fn main() {
 
   bin::main_loop::<_, KeyGenParams, _>(
     db,
-    feed.clone(),
+    Rpc { provider: provider.clone() },
     Scheduler::new(SmartContract { chain_id }),
-    TransactionPublisher::new({
+    TransactionPublisher::new(provider, {
       let relayer_hostname = env::var("ETHEREUM_RELAYER_HOSTNAME")
         .expect("ethereum relayer hostname wasn't specified")
         .to_string();

processor/ethereum/src/primitives/output.rs

@@ -1,6 +1,6 @@
 use std::io;
 
-use ciphersuite::{Ciphersuite, Secp256k1};
+use ciphersuite::{group::GroupEncoding, Ciphersuite, Secp256k1};
 
 use alloy_core::primitives::U256;
 
@@ -59,7 +59,10 @@ impl AsMut<[u8]> for OutputId {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub(crate) struct Output(pub(crate) EthereumInInstruction);
+pub(crate) struct Output {
+  pub(crate) key: <Secp256k1 as Ciphersuite>::G,
+  pub(crate) instruction: EthereumInInstruction,
+}
 impl ReceivedOutput<<Secp256k1 as Ciphersuite>::G, Address> for Output {
   type Id = OutputId;
   type TransactionId = [u8; 32];
@@ -71,40 +74,43 @@ impl ReceivedOutput<<Secp256k1 as Ciphersuite>::G, Address> for Output {
 
   fn id(&self) -> Self::Id {
     let mut id = [0; 40];
-    id[.. 32].copy_from_slice(&self.0.id.0);
-    id[32 ..].copy_from_slice(&self.0.id.1.to_le_bytes());
+    id[.. 32].copy_from_slice(&self.instruction.id.0);
+    id[32 ..].copy_from_slice(&self.instruction.id.1.to_le_bytes());
     OutputId(id)
   }
 
   fn transaction_id(&self) -> Self::TransactionId {
-    self.0.id.0
+    self.instruction.id.0
   }
 
   fn key(&self) -> <Secp256k1 as Ciphersuite>::G {
-    todo!("TODO")
+    self.key
   }
 
   fn presumed_origin(&self) -> Option<Address> {
-    Some(Address::from(self.0.from))
+    Some(Address::from(self.instruction.from))
   }
 
   fn balance(&self) -> Balance {
-    let coin = coin_to_serai_coin(&self.0.coin).unwrap_or_else(|| {
+    let coin = coin_to_serai_coin(&self.instruction.coin).unwrap_or_else(|| {
       panic!(
         "mapping coin from an EthereumInInstruction with coin {}, which we don't handle.",
         "this never should have been yielded"
       )
     });
-    Balance { coin, amount: amount_to_serai_amount(coin, self.0.amount) }
+    Balance { coin, amount: amount_to_serai_amount(coin, self.instruction.amount) }
   }
   fn data(&self) -> &[u8] {
-    &self.0.data
+    &self.instruction.data
   }
 
   fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
-    self.0.write(writer)
+    writer.write_all(self.key.to_bytes().as_ref())?;
+    self.instruction.write(writer)
   }
   fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
-    EthereumInInstruction::read(reader).map(Self)
+    let key = Secp256k1::read_G(reader)?;
+    let instruction = EthereumInInstruction::read(reader)?;
+    Ok(Self { key, instruction })
   }
 }

processor/ethereum/src/publisher.rs

@@ -1,34 +1,68 @@
 use core::future::Future;
+use std::sync::Arc;
 
-use crate::transaction::Transaction;
+use alloy_transport::{TransportErrorKind, RpcError};
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_provider::RootProvider;
+
+use tokio::sync::{RwLockReadGuard, RwLock};
+
+use ethereum_schnorr::PublicKey;
+use ethereum_router::{OutInstructions, Router};
+
+use crate::transaction::{Action, Transaction};
 
 #[derive(Clone)]
 pub(crate) struct TransactionPublisher {
+  initial_serai_key: PublicKey,
+  rpc: Arc<RootProvider<SimpleRequest>>,
+  router: Arc<RwLock<Option<Router>>>,
   relayer_url: String,
 }
 
 impl TransactionPublisher {
-  pub(crate) fn new(relayer_url: String) -> Self {
-    Self { relayer_url }
+  pub(crate) fn new(rpc: Arc<RootProvider<SimpleRequest>>, relayer_url: String) -> Self {
+    Self { initial_serai_key: todo!("TODO"), rpc, router: Arc::new(RwLock::new(None)), relayer_url }
+  }
+
+  // This will always return Ok(Some(_)) or Err(_), never Ok(None)
+  async fn router(&self) -> Result<RwLockReadGuard<'_, Option<Router>>, RpcError<TransportErrorKind>> {
+    let router = self.router.read().await;
+
+    // If the router is None, find it on-chain
+    if router.is_none() {
+      drop(router);
+      let mut router = self.router.write().await;
+      // Check again if it's None in case a different task already did this
+      if router.is_none() {
+        let Some(router_actual) = Router::new(self.rpc.clone(), &self.initial_serai_key).await? else {
+          Err(TransportErrorKind::Custom("publishing transaction yet couldn't find router on chain. was our node reset?".to_string().into()))?
+      };
+        *router = Some(router_actual);
+      }
+      return Ok(router.downgrade());
+    }
+
+    Ok(router)
   }
 }
 
 impl signers::TransactionPublisher<Transaction> for TransactionPublisher {
-  type EphemeralError = ();
+  type EphemeralError = RpcError<TransportErrorKind>;
 
   fn publish(
     &self,
     tx: Transaction,
   ) -> impl Send + Future<Output = Result<(), Self::EphemeralError>> {
-    // Convert from an Action (an internal representation of a signable event) to a TxLegacy
-    /* TODO
-    match tx.0 {
-      Action::SetKey { chain_id: _, nonce: _, key } => self.router.update_serai_key(key, tx.1),
-      Action::Batch { chain_id: _, nonce: _, outs } => self.router.execute(outs, tx.1),
-    }
-    */
-
     async move {
+      // Convert from an Action (an internal representation of a signable event) to a TxLegacy
+      let router = self.router().await?;
+      let router = router.as_ref().unwrap();
+      let tx = match tx.0 {
+        Action::SetKey { chain_id: _, nonce: _, key } => router.update_serai_key(&key, &tx.1),
+        Action::Batch { chain_id: _, nonce: _, outs } => router.execute(OutInstructions::from(outs.as_ref()), &tx.1),
+      };
+
       /*
       use tokio::{
         io::{AsyncReadExt, AsyncWriteExt},

processor/ethereum/src/scheduler.rs

@@ -68,6 +68,7 @@ impl smart_contract_scheduler::SmartContract<Rpc> for SmartContract {
 
     // TODO: Per-batch gas limit
     // TODO: Create several batches
+    // TODO: Handle fees
     let action = Action::Batch { chain_id: self.chain_id, nonce, outs };
 
     vec![(action.clone(), action.eventuality())]