std::unique_ptr Finish()

in src/parquet/metadata.cc [818:876]
50 lines of code
6 McCabe index (conditional complexity)

  std::unique_ptr<FileMetaData> Finish() {
    int64_t total_rows = 0;
    std::vector<format::RowGroup> row_groups;
    for (auto row_group = row_groups_.begin(); row_group != row_groups_.end();
         row_group++) {
      auto rowgroup = *((*row_group).get());
      row_groups.push_back(rowgroup);
      total_rows += rowgroup.num_rows;
    }
    metadata_->__set_num_rows(total_rows);
    metadata_->__set_row_groups(row_groups);

    if (key_value_metadata_) {
      metadata_->key_value_metadata.clear();
      metadata_->key_value_metadata.reserve(key_value_metadata_->size());
      for (int64_t i = 0; i < key_value_metadata_->size(); ++i) {
        format::KeyValue kv_pair;
        kv_pair.__set_key(key_value_metadata_->key(i));
        kv_pair.__set_value(key_value_metadata_->value(i));
        metadata_->key_value_metadata.push_back(kv_pair);
      }
      metadata_->__isset.key_value_metadata = true;
    }

    int32_t file_version = 0;
    switch (properties_->version()) {
      case ParquetVersion::PARQUET_1_0:
        file_version = 1;
        break;
      case ParquetVersion::PARQUET_2_0:
        file_version = 2;
        break;
      default:
        break;
    }
    metadata_->__set_version(file_version);
    metadata_->__set_created_by(properties_->created_by());

    // Users cannot set the `ColumnOrder` since we donot not have user defined sort order
    // in the spec yet.
    // We always default to `TYPE_DEFINED_ORDER`. We can expose it in
    // the API once we have user defined sort orders in the Parquet format.
    // TypeDefinedOrder implies choose SortOrder based on LogicalType/PhysicalType
    format::TypeDefinedOrder type_defined_order;
    format::ColumnOrder column_order;
    column_order.__set_TYPE_ORDER(type_defined_order);
    column_order.__isset.TYPE_ORDER = true;
    metadata_->column_orders.resize(schema_->num_columns(), column_order);
    metadata_->__isset.column_orders = true;

    parquet::schema::SchemaFlattener flattener(
        static_cast<parquet::schema::GroupNode*>(schema_->schema_root().get()),
        &metadata_->schema);
    flattener.Flatten();
    auto file_meta_data = std::unique_ptr<FileMetaData>(new FileMetaData());
    file_meta_data->impl_->metadata_ = std::move(metadata_);
    file_meta_data->impl_->InitSchema();
    return file_meta_data;
  }