From 652df1de79eaa26a272dfeb64c7082356c850ea1 Mon Sep 17 00:00:00 2001
From: Maciej Skrzypkowski <mskr@gmx.com>
Date: Wed, 17 Jul 2024 13:24:04 +0200
Subject: [PATCH] Checking of the epoch while sending the lookahead

---
 Node/src/ethereum_l1/consensus_layer.rs |  7 ++----
 Node/src/main.rs                        |  2 +-
 Node/src/node/mod.rs                    | 31 ++++++++++++++++---------
 Node/src/utils/config.rs                |  2 +-
 4 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/Node/src/ethereum_l1/consensus_layer.rs b/Node/src/ethereum_l1/consensus_layer.rs
index cde75f8..58eaa0e 100644
--- a/Node/src/ethereum_l1/consensus_layer.rs
+++ b/Node/src/ethereum_l1/consensus_layer.rs
@@ -13,13 +13,10 @@ impl ConsensusLayer {
         Ok(Self { client })
     }
 
-    // First iteration we get the next lookahead by checking the actual epoch number
-    // this will be improved so we keep synchronization with the CL
-    pub async fn get_latest_lookahead(&self) -> Result<Vec<ProposerDuty>, Error> {
+    pub async fn get_current_epoch(&self) -> Result<u64, Error> {
         let header = self.client.get_beacon_header_at_head().await?;
         let slot = header.header.message.slot;
-        let epoch = slot / 32;
-        self.get_lookahead(epoch + 1).await
+        Ok(slot / 32)
     }
 
     pub async fn get_lookahead(&self, epoch: u64) -> Result<Vec<ProposerDuty>, Error> {
diff --git a/Node/src/main.rs b/Node/src/main.rs
index ad7904f..8cbf4cd 100644
--- a/Node/src/main.rs
+++ b/Node/src/main.rs
@@ -29,7 +29,7 @@ async fn main() -> Result<(), Error> {
     )
     .await?;
     let mev_boost = mev_boost::MevBoost::new(&config.mev_boost_url);
-    let node = node::Node::new(node_rx, avs_p2p_tx, taiko, ethereum_l1, mev_boost);
+    let node = node::Node::new(node_rx, avs_p2p_tx, taiko, ethereum_l1, mev_boost).await?;
     node.entrypoint().await?;
     Ok(())
 }
diff --git a/Node/src/node/mod.rs b/Node/src/node/mod.rs
index 072007a..4fea0dd 100644
--- a/Node/src/node/mod.rs
+++ b/Node/src/node/mod.rs
@@ -9,24 +9,27 @@ pub struct Node {
     gas_used: u64,
     ethereum_l1: EthereumL1,
     _mev_boost: MevBoost, // temporary unused
+    epoch: u64,
 }
 
 impl Node {
-    pub fn new(
+    pub async fn new(
         node_rx: Receiver<String>,
         avs_p2p_tx: Sender<String>,
         taiko: Taiko,
         ethereum_l1: EthereumL1,
         mev_boost: MevBoost,
-    ) -> Self {
-        Self {
+    ) -> Result<Self, Error> {
+        let epoch = ethereum_l1.consensus_layer.get_current_epoch().await?;
+        Ok(Self {
             taiko,
             node_rx: Some(node_rx),
             avs_p2p_tx,
             gas_used: 0,
             ethereum_l1,
             _mev_boost: mev_boost,
-        }
+            epoch,
+        })
     }
 
     /// Consumes the Node and starts two loops:
@@ -58,7 +61,7 @@ impl Node {
         }
     }
 
-    async fn preconfirmation_loop(&self) {
+    async fn preconfirmation_loop(&mut self) {
         loop {
             let start_time = tokio::time::Instant::now();
             if let Err(err) = self.main_block_preconfirmation_step().await {
@@ -70,7 +73,7 @@ impl Node {
         }
     }
 
-    async fn main_block_preconfirmation_step(&self) -> Result<(), Error> {
+    async fn main_block_preconfirmation_step(&mut self) -> Result<(), Error> {
         let pending_tx_lists = self
             .taiko
             .get_pending_l2_tx_lists()
@@ -85,11 +88,17 @@ impl Node {
         self.taiko
             .advance_head_to_new_l2_block(pending_tx_lists.tx_lists, self.gas_used)
             .await?;
-        let lookahead = self
-            .ethereum_l1
-            .consensus_layer
-            .get_latest_lookahead()
-            .await?;
+
+        let current_epoch = self.ethereum_l1.consensus_layer.get_current_epoch().await?;
+        let lookahead = if current_epoch != self.epoch {
+            self.epoch = current_epoch;
+            self.ethereum_l1
+                .consensus_layer
+                .get_lookahead(self.epoch + 1)
+                .await?
+        } else {
+            vec![]
+        };
         self.ethereum_l1
             .execution_layer
             .propose_new_block(
diff --git a/Node/src/utils/config.rs b/Node/src/utils/config.rs
index 3b0da95..857db25 100644
--- a/Node/src/utils/config.rs
+++ b/Node/src/utils/config.rs
@@ -74,4 +74,4 @@ L1 slot duration: {}
 
         config
     }
-}
\ No newline at end of file
+}