Method LeafReader

cpp/src/parquet/arrow/reader.cc:455–474

class LeafReader : public ColumnReaderImpl {
 public:
  LeafReader(std::shared_ptr<ReaderContext> ctx, std::shared_ptr<Field> field,
             std::unique_ptr<FileColumnIterator> input,
             ::parquet::internal::LevelInfo leaf_info)
      : ctx_(std::move(ctx)),
        field_(std::move(field)),
        input_(std::move(input)),
        descr_(input_->descr()) {
    const auto type_id = field_->type()->id();
    // If binary-like, RecordReader is able to read directly as the concrete type
    // so as to avoid offset limitations.
    std::shared_ptr<DataType> type_for_reading =
        (::arrow::is_base_binary_like(type_id) || ::arrow::is_binary_view_like(type_id))
            ? field_->type()
            : nullptr;
    record_reader_ = RecordReader::Make(
        descr_, leaf_info, ctx_->pool,
        /*read_dictionary=*/field_->type()->id() == ::arrow::Type::DICTIONARY,
        /*read_dense_for_nullable=*/false, /*arrow_type=*/type_for_reading);
    NextRowGroup();
  }

  Status GetDefLevels(const int16_t** data, int64_t* length) final {
    *data = record_reader_->def_levels();