Repo created

libs/indexer/centers_table.hpp

@@ -0,0 +1,96 @@
+#pragma once
+
+#include "coding/geometry_coding.hpp"
+#include "coding/map_uint32_to_val.hpp"
+#include "coding/point_coding.hpp"
+
+#include "geometry/point2d.hpp"
+
+#include <cstdint>
+#include <memory>
+#include <vector>
+
+class FilesContainerR;
+class Reader;
+class Writer;
+
+namespace search
+{
+// A wrapper class around serialized centers-table.
+class CentersTable
+{
+public:
+  enum class Version : uint8_t
+  {
+    V0 = 0,
+    V1 = 1,
+    Latest = V1
+  };
+
+  struct Header
+  {
+    template <typename Sink>
+    void Serialize(Sink & sink) const
+    {
+      CHECK_EQUAL(static_cast<uint8_t>(m_version), static_cast<uint8_t>(Version::V1), ());
+      WriteToSink(sink, static_cast<uint8_t>(m_version));
+      WriteToSink(sink, m_geometryParamsOffset);
+      WriteToSink(sink, m_geometryParamsSize);
+      WriteToSink(sink, m_centersOffset);
+      WriteToSink(sink, m_centersSize);
+    }
+
+    void Read(Reader & reader);
+
+    Version m_version = Version::Latest;
+    // All offsets are relative to the start of the section (offset of header is zero).
+    uint32_t m_geometryParamsOffset = 0;
+    uint32_t m_geometryParamsSize = 0;
+    uint32_t m_centersOffset = 0;
+    uint32_t m_centersSize = 0;
+  };
+
+  // Tries to get |center| of the feature identified by |id|.  Returns
+  // false if table does not have entry for the feature.
+  [[nodiscard]] bool Get(uint32_t id, m2::PointD & center);
+
+  uint64_t Count() const { return m_map->Count(); }
+
+  // Loads CentersTable instance. Note that |reader| must be alive
+  // until the destruction of loaded table. Returns nullptr if
+  // CentersTable can't be loaded.
+  static std::unique_ptr<CentersTable> LoadV0(Reader & reader, serial::GeometryCodingParams const & codingParams);
+
+  static std::unique_ptr<CentersTable> LoadV1(Reader & reader);
+
+private:
+  using Map = MapUint32ToValue<m2::PointU>;
+
+  bool Init(Reader & reader, serial::GeometryCodingParams const & codingParams, m2::RectD const & limitRect);
+
+  serial::GeometryCodingParams m_codingParams;
+  std::unique_ptr<Map> m_map;
+  std::unique_ptr<Reader> m_centersSubreader;
+  m2::RectD m_limitRect;
+  Version m_version = Version::Latest;
+};
+
+class CentersTableBuilder
+{
+public:
+  void SetGeometryParams(m2::RectD const & limitRect, double pointAccuracy = kMwmPointAccuracy);
+  void Put(uint32_t featureId, m2::PointD const & center);
+  void WriteBlock(Writer & w, std::vector<m2::PointU>::const_iterator begin,
+                  std::vector<m2::PointU>::const_iterator end) const;
+  void Freeze(Writer & writer) const;
+
+  void SetGeometryCodingParamsV0ForTests(serial::GeometryCodingParams const & codingParams);
+  void PutV0ForTests(uint32_t featureId, m2::PointD const & center);
+  void FreezeV0ForTests(Writer & writer) const;
+
+private:
+  serial::GeometryCodingParams m_codingParams;
+  m2::RectD m_limitRect;
+  MapUint32ToValueBuilder<m2::PointU> m_builder;
+};
+}  // namespace search