rpc: getter for nullifier queries by epoch index

crates/core/component/funding/src/component/liquidity_tournament/nullifier/mod.rs

@@ -8,7 +8,8 @@ use penumbra_sdk_sct::{component::clock::EpochRead, Nullifier};
 
 #[async_trait]
 pub trait NullifierRead: StateRead {
-    /// Returns the `TransactionId` if the nullifier has been spent; otherwise, returns None.
+    /// Returns the `TransactionId` if the nullifier has been spent in the current epoch;
+    /// Otherwise, returns None.
     async fn get_lqt_spent_nullifier(&self, nullifier: Nullifier) -> Option<TransactionId> {
         // Grab the ambient epoch index.
         let epoch_index = self
@@ -29,6 +30,26 @@ pub trait NullifierRead: StateRead {
 
         tx_id
     }
+
+    /// Returns the `TransactionId` if the nullifier has been spent in a specific epoch;
+    /// Otherwise, returns None.
+    async fn get_lqt_spent_nullifier_by_epoch(
+        &self,
+        nullifier: Nullifier,
+        epoch_index: u64,
+    ) -> Option<TransactionId> {
+        let nullifier_key = &state_key::lqt::v1::nullifier::key(epoch_index, &nullifier);
+
+        let tx_id: Option<TransactionId> = self
+            .nonverifiable_get(&nullifier_key.as_bytes())
+            .await
+            .expect(&format!(
+                "failed to retrieve key {} from non-verifiable storage",
+                nullifier_key,
+            ));
+
+        tx_id
+    }
 }
 
 impl<T: StateRead + ?Sized> NullifierRead for T {}

crates/core/component/funding/src/component/rpc.rs

@@ -47,7 +47,9 @@ impl FundingService for Server {
         };
 
         // Perform a state nullifier lookup.
-        let maybe_tx_id = state.get_lqt_spent_nullifier(nullifier).await;
+        let maybe_tx_id = state
+            .get_lqt_spent_nullifier_by_epoch(nullifier, epoch_index)
+            .await;
 
         if let Some(tx_id) = maybe_tx_id {
             // Nullifier was spent and user has already voted.