chore: retrieve single pooled tx by hash (#6785)

crates/transaction-pool/src/lib.rs

@@ -417,6 +417,10 @@ where
         self.pool.get_pooled_transaction_elements(tx_hashes, limit)
     }
 
+    fn get_pooled_transaction_element(&self, tx_hash: TxHash) -> Option<PooledTransactionsElement> {
+        self.pool.get_pooled_transaction_element(tx_hash)
+    }
+
     fn best_transactions(
         &self,
     ) -> Box<dyn BestTransactions<Item = Arc<ValidPoolTransaction<Self::Transaction>>>> {

crates/transaction-pool/src/noop.rs

@@ -135,6 +135,13 @@ impl TransactionPool for NoopTransactionPool {
         vec![]
     }
 
+    fn get_pooled_transaction_element(
+        &self,
+        _tx_hash: TxHash,
+    ) -> Option<PooledTransactionsElement> {
+        None
+    }
+
     fn best_transactions(
         &self,
     ) -> Box<dyn BestTransactions<Item = Arc<ValidPoolTransaction<Self::Transaction>>>> {

crates/transaction-pool/src/pool/mod.rs

@@ -341,6 +341,21 @@ where
         elements
     }
 
+    /// Returns converted [PooledTransactionsElement] for the given transaction hash.
+    pub(crate) fn get_pooled_transaction_element(
+        &self,
+        tx_hash: TxHash,
+    ) -> Option<PooledTransactionsElement> {
+        self.get(&tx_hash).and_then(|transaction| {
+            let tx = transaction.to_recovered_transaction().into_signed();
+            if tx.is_eip4844() {
+                self.get_blob_transaction(tx).map(PooledTransactionsElement::BlobTransaction)
+            } else {
+                Some(PooledTransactionsElement::from(tx))
+            }
+        })
+    }
+
     /// Updates the entire pool after a new block was executed.
     pub(crate) fn on_canonical_state_change(&self, update: CanonicalStateUpdate<'_>) {
         trace!(target: "txpool", ?update, "updating pool on canonical state change");

crates/transaction-pool/src/traits.rs

@@ -221,6 +221,16 @@ pub trait TransactionPool: Send + Sync + Clone {
         limit: GetPooledTransactionLimit,
     ) -> Vec<PooledTransactionsElement>;
 
+    /// Returns converted [PooledTransactionsElement] for the given transaction hash.
+    ///
+    /// This adheres to the expected behavior of
+    /// [`GetPooledTransactions`](https://github.com/ethereum/devp2p/blob/master/caps/eth.md#getpooledtransactions-0x09):
+    ///
+    /// If the transaction is a blob transaction, the sidecar will be included.
+    ///
+    /// Consumer: P2P
+    fn get_pooled_transaction_element(&self, tx_hash: TxHash) -> Option<PooledTransactionsElement>;
+
     /// Returns an iterator that yields transactions that are ready for block production.
     ///
     /// Consumer: Block production