Store metadata about original OSM data, and return it in the API response, if available.

include/engine/datafacade/contiguous_internalmem_datafacade.hpp

@@ -137,6 +137,7 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
     extractor::Datasources *m_datasources;
 
     std::uint32_t m_check_sum;
+    StringView m_data_timestamp;
     util::vector_view<util::Coordinate> m_coordinate_list;
     extractor::PackedOSMIDsView m_osmnodeid_list;
     util::vector_view<std::uint32_t> m_lane_description_offsets;
@@ -183,6 +184,8 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
 
         m_check_sum = *index.GetBlockPtr<std::uint32_t>("/common/connectivity_checksum");
 
+        m_data_timestamp = make_timestamp_view(index, "/common/timestamp");
+
         std::tie(m_coordinate_list, m_osmnodeid_list) =
             make_nbn_data_view(index, "/common/nbn_data");
 
@@ -432,6 +435,11 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
 
     std::uint32_t GetCheckSum() const override final { return m_check_sum; }
 
+    std::string GetTimestamp() const override final
+    {
+        return std::string(m_data_timestamp.begin(), m_data_timestamp.end());
+    }
+
     GeometryID GetGeometryIndex(const NodeID id) const override final
     {
         return edge_based_node_data.GetGeometryID(id);

include/engine/datafacade/datafacade_base.hpp

@@ -74,6 +74,8 @@ class BaseDataFacade
 
     virtual std::uint32_t GetCheckSum() const = 0;
 
+    virtual std::string GetTimestamp() const = 0;
+
     // node and edge information access
     virtual util::Coordinate GetCoordinateOfNode(const NodeID id) const = 0;