Hint to MASP client block range to fetch

Author: sug0

crates/sdk/src/masp/utilities.rs

@@ -69,6 +69,11 @@ impl<M: Clone> Clone for LinearBackoffSleepMaspClient<M> {
 impl<M: MaspClient> MaspClient for LinearBackoffSleepMaspClient<M> {
     type Error = <M as MaspClient>::Error;
 
+    #[inline]
+    fn hint(&mut self, from: BlockHeight, to: BlockHeight) {
+        self.middleware_client.hint(from, to);
+    }
+
     async fn last_block_height(
         &self,
     ) -> Result<Option<BlockHeight>, Self::Error> {
@@ -181,6 +186,8 @@ impl<C> LedgerMaspClient<C> {
 impl<C: Client + Send + Sync> MaspClient for LedgerMaspClient<C> {
     type Error = Error;
 
+    fn hint(&mut self, _from: BlockHeight, _to: BlockHeight) {}
+
     async fn last_block_height(&self) -> Result<Option<BlockHeight>, Error> {
         let maybe_block = crate::rpc::query_block(&self.inner.client).await?;
         Ok(maybe_block.map(|b| b.height))
@@ -426,6 +433,12 @@ impl IndexerMaspClient {
 impl MaspClient for IndexerMaspClient {
     type Error = Error;
 
+    fn hint(&mut self, from: BlockHeight, to: BlockHeight) {
+        if to.0 - from.0 + 1 < self.shared.max_concurrent_fetches as _ {
+            _ = self.shared.block_index.set(None);
+        }
+    }
+
     async fn last_block_height(&self) -> Result<Option<BlockHeight>, Error> {
         use serde::Deserialize;
 

crates/shielded_token/src/masp/shielded_sync/dispatcher.rs

@@ -542,6 +542,9 @@ where
 
         self.force_redraw_progress_bars();
 
+        self.client
+            .hint(initial_state.start_height, initial_state.last_query_height);
+
         Ok(initial_state)
     }
 

crates/shielded_token/src/masp/shielded_sync/utils.rs

@@ -385,6 +385,10 @@ pub trait MaspClient: Clone {
     /// Error type returned by the methods of this trait
     type Error: std::error::Error + Send + Sync + 'static;
 
+    /// Hint to this [`MaspClient`] implementation the block range
+    /// that will be fetched.
+    fn hint(&mut self, from: BlockHeight, to: BlockHeight);
+
     /// Return the last block height we can retrieve data from.
     #[allow(async_fn_in_trait)]
     async fn last_block_height(

crates/shielded_token/src/masp/test_utils.rs

@@ -386,6 +386,8 @@ pub enum TestError {
 impl MaspClient for TestingMaspClient {
     type Error = TestError;
 
+    fn hint(&mut self, _from: BlockHeight, _to: BlockHeight) {}
+
     async fn last_block_height(
         &self,
     ) -> Result<Option<BlockHeight>, Self::Error> {