Method MergeGeometryInternal

cpp/src/parquet/geospatial/util_internal.cc:168–226

}

void WKBGeometryBounder::MergeGeometryInternal(WKBBuffer* src, bool record_wkb_type,
                                               int depth) {
  if (depth > 128) {
    throw ParquetException("WKB geometry has too many levels of nesting");
  }

  uint8_t endian = src->ReadUInt8();
#if ARROW_LITTLE_ENDIAN
  bool swap = endian != 0x01;
#else
  bool swap = endian != 0x00;
#endif

  uint32_t wkb_geometry_type = src->ReadUInt32(swap);
  auto geometry_type_and_dimensions = ParseGeometryType(wkb_geometry_type);
  auto [geometry_type, dimensions] = geometry_type_and_dimensions;

  // Keep track of geometry types encountered if at the top level
  if (record_wkb_type) {
    geospatial_types_.insert(static_cast<int32_t>(wkb_geometry_type));
  }

  switch (geometry_type) {
    case GeometryType::kPoint:
      MergeSequence(src, dimensions, 1, swap);
      break;

    case GeometryType::kLinestring: {
      uint32_t n_coords = src->ReadUInt32(swap);
      MergeSequence(src, dimensions, n_coords, swap);
      break;
    }
    case GeometryType::kPolygon: {
      uint32_t n_parts = src->ReadUInt32(swap);
      for (uint32_t i = 0; i < n_parts; i++) {
        uint32_t n_coords = src->ReadUInt32(swap);
        MergeSequence(src, dimensions, n_coords, swap);
      }
      break;
    }

    // These are all encoded the same in WKB, even though this encoding would
    // allow for parts to be of a different geometry type or different dimensions.
    // For the purposes of bounding, this does not cause us problems. We pass
    // record_wkb_type = false because we do not want the child geometry to be
    // added to the geometry_types list (e.g., for a MultiPoint, we only want
    // the code for MultiPoint to be added, not the code for Point).
    case GeometryType::kMultiPoint:
    case GeometryType::kMultiLinestring:
    case GeometryType::kMultiPolygon:
    case GeometryType::kGeometryCollection: {
      uint32_t n_parts = src->ReadUInt32(swap);
      for (uint32_t i = 0; i < n_parts; i++) {
        MergeGeometryInternal(src, /*record_wkb_type*/ false, depth + 1);
      }
      break;
    }
  }