Feat(standalone): Function to get latest/earliest block

engine-standalone-storage/src/lib.rs

@@ -53,6 +53,36 @@ impl Storage {
  })
  }
 
+ pub fn get_latest_block(&self) -> Result<(H256, u64), error::Error> {
+ self.block_read(rocksdb::IteratorMode::End)
+ }
+
+ pub fn get_earliest_block(&self) -> Result<(H256, u64), error::Error> {
+ self.block_read(rocksdb::IteratorMode::Start)
+ }
+
+ fn block_read(&self, mode: rocksdb::IteratorMode) -> Result<(H256, u64), error::Error> {
+ let upper_bound = construct_storage_key(StoragePrefix::BlockHash, &u64::MAX.to_be_bytes());
+ let lower_bound = construct_storage_key(StoragePrefix::BlockHash, &[]);
+ let prefix_len = lower_bound.len();
+ let mut opt = rocksdb::ReadOptions::default();
+ opt.set_iterate_upper_bound(upper_bound);
+ opt.set_iterate_lower_bound(lower_bound);
+
+ let mut iter = self.db.iterator_opt(mode, opt);
+ iter.next()
+ .map(|(key, value)| {
+ let block_height = {
+ let mut buf = [0u8; 8];
+ buf.copy_from_slice(&key[prefix_len..]);
+ u64::from_be_bytes(buf)
+ };
+ let block_hash = H256::from_slice(&value);
+ (block_hash, block_height)
+ })
+ .ok_or(error::Error::NoBlockAtHeight(0))
+ }
+
  pub fn get_block_hash_by_height(&self, block_height: u64) -> Result<H256, error::Error> {
  let storage_key =
  construct_storage_key(StoragePrefix::BlockHash, &block_height.to_be_bytes());

engine-tests/src/tests/standalone/storage.rs

@@ -195,6 +195,14 @@ fn test_block_index() {
  block_metadata,
  storage.get_block_metadata(block_hash).unwrap()
  );
+ assert_eq!(
+ (block_hash, block_height),
+ storage.get_latest_block().unwrap(),
+ );
+ assert_eq!(
+ (block_hash, block_height),
+ storage.get_earliest_block().unwrap(),
+ );
 
  // block hash / height that do not exist are errors
  let missing_block_height = block_height + 1;
@@ -214,6 +222,40 @@ fn test_block_index() {
  other => panic!("Unexpected response: {:?}", other),
  }
 
+ // insert later block
+ let next_height = block_height + 1;
+ let next_hash = H256([0xaa; 32]);
+ storage
+ .set_block_data(next_hash, next_height, block_metadata.clone())
+ .unwrap();
+
+ // check earliest+latest blocks are still correct
+ assert_eq!(
+ (next_hash, next_height),
+ storage.get_latest_block().unwrap(),
+ );
+ assert_eq!(
+ (block_hash, block_height),
+ storage.get_earliest_block().unwrap(),
+ );
+
+ // insert earlier block
+ let prev_height = block_height - 1;
+ let prev_hash = H256([0xbb; 32]);
+ storage
+ .set_block_data(prev_hash, prev_height, block_metadata.clone())
+ .unwrap();
+
+ // check earliest+latest blocks are still correct
+ assert_eq!(
+ (next_hash, next_height),
+ storage.get_latest_block().unwrap(),
+ );
+ assert_eq!(
+ (prev_hash, prev_height),
+ storage.get_earliest_block().unwrap(),
+ );
+
  drop(storage);
  temp_dir.close().unwrap();
 }