void UpdateLRU(const Key& key, const std::shared_ptr<Block>& block,
                 TF_Status* status) ABSL_LOCKS_EXCLUDED(mu_);

  /// Remove all blocks of a file, with mu_ already held.
  void RemoveFile_Locked(const std::string& filename)
      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);

  /// Remove the block `entry` from the block map and LRU list, and update the
  /// cache size accordingly.