Tree cache for timetable loading

include/nigiri/shapes_storage.h

@@ -18,6 +18,7 @@ struct shapes_storage {
 
   cista::mmap mm(char const* file);
 
+  void add(shapes_storage* other);
   std::span<geo::latlng const> get_shape(shape_idx_t) const;
   std::span<geo::latlng const> get_shape(trip_idx_t) const;
   std::span<geo::latlng const> get_shape(trip_idx_t,

include/nigiri/stop.h

@@ -8,6 +8,11 @@ namespace nigiri {
 
 struct stop {
   using value_type = location_idx_t::value_t;
+  static constexpr auto const kTotalBits = 8 * sizeof(value_type);
+  static constexpr auto const kLocationBits = 28U;
+  static constexpr auto const kMaxLocation =
+      std::numeric_limits<location_idx_t::value_t>::max() >>
+      (kTotalBits - kLocationBits);
 
   stop(location_idx_t::value_t const val) {
     std::memcpy(this, &val, sizeof(value_type));
@@ -24,7 +29,12 @@ struct stop {
         in_allowed_wheelchair_{in_allowed_wheelchair ? 1U : 0U},
         out_allowed_wheelchair_{out_allowed_wheelchair ? 1U : 0U} {}
 
-  location_idx_t location_idx() const { return location_idx_t{location_}; }
+  location_idx_t location_idx() const {
+    auto const location_idx = location_ != kMaxLocation
+                                  ? location_idx_t{location_}
+                                  : location_idx_t::invalid();
+    return location_idx;
+  }
   bool in_allowed_wheelchair() const { return in_allowed_wheelchair_ != 0U; }
   bool out_allowed_wheelchair() const { return out_allowed_wheelchair_ != 0U; }
   bool in_allowed() const { return in_allowed_ != 0U; }
@@ -72,7 +82,7 @@ struct stop {
 
   friend auto operator<=>(stop const&, stop const&) = default;
 
-  location_idx_t::value_t location_ : 28;
+  location_idx_t::value_t location_ : kLocationBits;
   location_idx_t::value_t in_allowed_ : 1;
   location_idx_t::value_t out_allowed_ : 1;
   location_idx_t::value_t in_allowed_wheelchair_ : 1;

include/nigiri/string_store.h

@@ -51,13 +51,15 @@ struct string_store {
       cache_ = o.cache_;
       resolve();
     }
+    return *this;
   }
   string_store& operator=(string_store&& o) {
     if (&o != this) {
       strings_ = std::move(o.strings_);
       cache_ = std::move(o.cache_);
       resolve();
     }
+    return *this;
   }
 
   template <typename Ctx, typename Fn>

include/nigiri/timetable.h

@@ -364,6 +364,8 @@ struct timetable {
 
   friend std::ostream& operator<<(std::ostream&, timetable const&);
 
+  void merge(timetable const&);
+
   void write(cista::memory_holder&) const;
   void write(std::filesystem::path const&) const;
   static cista::wrapped<timetable> read(std::filesystem::path const&);