difference transmission of source databases done

luprex/core/cpp/util.hpp

@@ -39,9 +39,15 @@ std::string id_vector_debug_string(const IdVector &idv);
 // Unions and sorts two ID vectors.
 IdVector sort_union_id_vectors(const IdVector &v1, const IdVector &v2);
 
+// Get a 64-bit hashvalue for a string.
+HashValue hash_string(const std::string &str);
+
 // Get a 64-bit hashvalue for an ID vector.
 HashValue hash_id_vector(const IdVector &idv);
 
+// Convert a hash to a hexadecimal string.
+std::string hash_to_hex(const HashValue &hash);
+
 // Split a string into multiple strings
 StringVec split(const std::string &s, char sep);