header.hpp

Go to the documentation of this file.

#pragma once
 
#include <fcb/error.hpp>
#include <fcb/layout.hpp>
#include <fcb/range_reader.hpp>
 
#include <array>
#include <cstdint>
#include <memory>
#include <optional>
#include <string>
#include <vector>
 
// The generated FlatBuffers types live in the GLOBAL namespace (every
// `namespace FlatCityBuf;` in src/fbs/*.fbs is commented out). Forward
// declare rather than including the generated headers, so consumers of
// this public header never inherit them.
struct Header;
 
namespace fcb {
 
namespace detail {
struct HeaderAccess;
}
 
struct ColumnInfo {
    std::uint16_t index;
    std::string name;
    std::uint8_t type;  // ::ColumnType, as its underlying ubyte
    bool nullable;
};
 
struct AttrIndexInfo {
    std::uint16_t column_index;
    std::uint32_t length;  // whole blob, INCLUDING its payload section
    std::uint16_t branching_factor;
    std::uint32_t num_unique_items;  // unique KEYS, not features
    std::uint64_t begin;             // absolute byte offset in the file
};
 
struct FileInfo {
    std::uint64_t features_count = 0;
    std::uint16_t index_node_size = 0;
    std::vector<ColumnInfo> columns;
    std::vector<ColumnInfo> semantic_columns;
 
    bool has_extent = false;
    std::array<double, 6> geographical_extent{};  // minx,miny,minz,maxx,maxy,maxz
 
    bool has_transform = false;
    std::array<double, 3> scale{};
    std::array<double, 3> translate{};
 
    std::string crs;
    std::string cityjson_version;
 
    std::optional<std::string> identifier;
    std::optional<std::string> title;
    std::optional<std::string> reference_date;
 
    std::optional<std::string> poc_contact_name;
    std::optional<std::string> poc_contact_type;
    std::optional<std::string> poc_role;
    std::optional<std::string> poc_phone;
    std::optional<std::string> poc_email;
    std::optional<std::string> poc_website;
    std::string poc_address_thoroughfare_number;
    std::string poc_address_thoroughfare_name;
    std::string poc_address_locality;
    std::string poc_address_postcode;
    std::string poc_address_country;
};
 
class HeaderView {
  public:
    HeaderView() = default;
 
    const FileInfo& info() const { return info_; }
    const FileLayout& layout() const { return layout_; }
    const std::vector<AttrIndexInfo>& attr_indices() const { return attr_indices_; }
 
  private:
    friend struct detail::HeaderAccess;
    friend HeaderView read_header(std::shared_ptr<RangeReader> reader);
 
    const ::Header* raw() const;
 
    std::shared_ptr<const std::vector<std::uint8_t>> buffer_;
    FileInfo info_;
    FileLayout layout_{};
    std::vector<AttrIndexInfo> attr_indices_;
};
 
HeaderView read_header(std::shared_ptr<RangeReader> reader);
 
}  // namespace fcb