[Solution Submission] Return as soon as tx has been submitted to memp…

…ool (#2432)

crates/driver/src/domain/mempools.rs

@@ -104,11 +104,16 @@ impl Mempools {
                 competition::solution::settlement::Internalization::Enable,
             )
         };
-        let hash = mempool.submit(tx.clone(), settlement.gas, solver).await?;
+
+        // Instantiate block stream and skip the current block before we submit the
+        // settlement. This way we only run iterations in blocks that can potentially
+        // include the settlement.
         let mut block_stream = into_stream(self.ethereum.current_block().clone());
+        block_stream.next().await;
+
+        let hash = mempool.submit(tx.clone(), settlement.gas, solver).await?;
         loop {
-            // Wait for the next block to be mined or we time out. Block stream immediately
-            // yields the latest block, thus the first iteration starts immediately.
+            // Wait for the next block to be mined or we time out.
             if tokio::time::timeout_at(mempool.config().deadline(), block_stream.next())
                 .await
                 .is_err()

crates/driver/src/infra/mempool/mod.rs

@@ -57,6 +57,8 @@ impl Inner {
         Self { config, transport }
     }
 
+    /// Submits a transaction to the mempool. Returns optimistically as soon as
+    /// the transaction is pending.
     pub async fn submit(
         &self,
         tx: eth::Tx,
@@ -74,6 +76,7 @@ impl Inner {
             .value(tx.value.0)
             .gas(gas.limit.0)
             .access_list(web3::types::AccessList::from(tx.access_list))
+            .resolve(ethcontract::transaction::ResolveCondition::Pending)
             .send()
             .await
             .map(|result| eth::TxId(result.hash()))