Method ScanBatch

cpp/src/arrow/dataset/file_csv.cc:80–86

        best_guess_bytes_per_batch_(best_guess_bytes_per_batch) {}

  Future<std::shared_ptr<RecordBatch>> ScanBatch(int batch_number) override {
    // This should be called in increasing order but let's verify that in case it changes.
    // It would be easy enough to handle out of order but no need for that complexity at
    // the moment.
    DCHECK_EQ(scanned_so_far_++, batch_number);
    return reader_->ReadNextAsync();
  }

  int64_t EstimatedDataBytes(int batch_number) override {
    return best_guess_bytes_per_batch_;