feat: check if blocknumber is latest block number (#2428)

crates/interfaces/src/provider.rs

@@ -74,8 +74,6 @@ pub enum ProviderError {
     /// Some error occurred while interacting with the state tree.
     #[error("Unknown error occurred while interacting with the state trie.")]
     StateTrie,
-    #[error("History state root, can't be calculated")]
-    HistoryStateRoot,
     /// Thrown when required header related data was not found but was required.
     #[error("requested data not found")]
     HeaderNotFound,
@@ -91,6 +89,7 @@ pub enum ProviderError {
     /// Thrown when we failed to lookup a block for the pending state
     #[error("Unknown block hash: {0:}")]
     UnknownBlockHash(H256),
+    /// Unable to compute state root on top of historical block
     #[error("Unable to compute state root on top of historical block")]
     StateRootNotAvailableForHistoricalBlock,
 }

crates/storage/provider/src/providers/database.rs

@@ -54,6 +54,10 @@ impl<DB: Database> ShareableDatabase<DB> {
     ) -> Result<StateProviderBox<'_>> {
         let tx = self.db.tx()?;
 
+        if is_latest_block_number(&tx, block_number)? {
+            return Ok(Box::new(LatestStateProvider::new(tx)))
+        }
+
         // +1 as the changeset that we want is the one that was applied after this block.
         block_number += 1;
 
@@ -68,6 +72,10 @@ impl<DB: Database> ShareableDatabase<DB> {
             .get::<tables::HeaderNumbers>(block_hash)?
             .ok_or(ProviderError::BlockHash { block_hash })?;
 
+        if is_latest_block_number(&tx, block_number)? {
+            return Ok(Box::new(LatestStateProvider::new(tx)))
+        }
+
         // +1 as the changeset that we want is the one that was applied after this block.
         // as the  changeset contains old values.
         block_number += 1;
@@ -145,11 +153,7 @@ impl<DB: Database> BlockIdProvider for ShareableDatabase<DB> {
     }
 
     fn best_block_number(&self) -> Result<BlockNumber> {
-        Ok(self
-            .db
-            .view(|tx| tx.get::<tables::SyncStage>("Finish".to_string()))?
-            .map_err(Into::<reth_interfaces::db::Error>::into)?
-            .unwrap_or_default())
+        Ok(self.db.view(|tx| best_block_number(tx))??.unwrap_or_default())
     }
 
     fn block_number(&self, hash: H256) -> Result<Option<BlockNumber>> {
@@ -452,6 +456,44 @@ impl<DB: Database> EvmEnvProvider for ShareableDatabase<DB> {
     }
 }
 
+/// Fetches checks if the block number is the latest block number.
+#[inline]
+fn is_latest_block_number<'a, TX>(
+    tx: &TX,
+    block_number: BlockNumber,
+) -> std::result::Result<bool, reth_interfaces::db::Error>
+where
+    TX: DbTx<'a> + Send + Sync,
+{
+    // check if the block number is the best block number
+    // there's always at least one header in the database (genesis)
+    let best = best_block_number(tx)?.unwrap_or_default();
+    let last = last_canonical_header(tx)?.map(|(last, _)| last).unwrap_or_default();
+    Ok(block_number == best && block_number == last)
+}
+
+/// Fetches the best block number from the database.
+#[inline]
+fn best_block_number<'a, TX>(
+    tx: &TX,
+) -> std::result::Result<Option<BlockNumber>, reth_interfaces::db::Error>
+where
+    TX: DbTx<'a> + Send + Sync,
+{
+    tx.get::<tables::SyncStage>("Finish".to_string())
+}
+
+/// Fetches the last canonical header from the database.
+#[inline]
+fn last_canonical_header<'a, TX>(
+    tx: &TX,
+) -> std::result::Result<Option<(BlockNumber, BlockHash)>, reth_interfaces::db::Error>
+where
+    TX: DbTx<'a> + Send + Sync,
+{
+    tx.cursor_read::<tables::CanonicalHeaders>()?.last()
+}
+
 #[cfg(test)]
 mod tests {
     use super::ShareableDatabase;

crates/storage/provider/src/providers/mod.rs

@@ -299,7 +299,6 @@ where
         if let Some(pending) = self.tree.find_pending_state_provider(block) {
             return self.pending_with_provider(pending)
         }
-
         // not found in tree, check database
         self.history_by_block_hash(block)
     }

crates/storage/provider/src/providers/post_state_provider.rs

@@ -94,6 +94,6 @@ impl<SP: StateProvider, PSDP: PostStateDataProvider> StateProvider for PostState
         _address: Address,
         _keys: &[H256],
     ) -> Result<(Vec<Bytes>, H256, Vec<Vec<Bytes>>)> {
-        Err(ProviderError::HistoryStateRoot.into())
+        Err(ProviderError::StateRootNotAvailableForHistoricalBlock.into())
     }
 }

crates/storage/provider/src/providers/state/historical.rs

@@ -149,7 +149,7 @@ impl<'a, 'b, TX: DbTx<'a>> StateProvider for HistoricalStateProviderRef<'a, 'b,
         _address: Address,
         _keys: &[H256],
     ) -> Result<(Vec<Bytes>, H256, Vec<Vec<Bytes>>)> {
-        Err(ProviderError::HistoryStateRoot.into())
+        Err(ProviderError::StateRootNotAvailableForHistoricalBlock.into())
     }
 }