Function MakeRowTableFromColumn

cpp/src/arrow/compute/row/row_test.cc:31–62

namespace {

Result<RowTableImpl> MakeRowTableFromColumn(const std::shared_ptr<Array>& column,
                                            int64_t num_rows, int row_alignment,
                                            int string_alignment) {
  DCHECK_GE(column->length(), num_rows);
  MemoryPool* pool = default_memory_pool();

  std::vector<KeyColumnArray> column_arrays;
  std::vector<Datum> values{column};
  ExecBatch batch(std::move(values), num_rows);
  RETURN_NOT_OK(ColumnArraysFromExecBatch(batch, &column_arrays));

  std::vector<KeyColumnMetadata> column_metadatas;
  RETURN_NOT_OK(ColumnMetadatasFromExecBatch(batch, &column_metadatas));
  RowTableMetadata table_metadata;
  table_metadata.FromColumnMetadataVector(column_metadatas, row_alignment,
                                          string_alignment);

  RowTableImpl row_table;
  RETURN_NOT_OK(row_table.Init(pool, table_metadata));

  RowTableEncoder row_encoder;
  row_encoder.Init(column_metadatas, row_alignment, string_alignment);
  row_encoder.PrepareEncodeSelected(0, num_rows, column_arrays);

  std::vector<uint16_t> row_ids(num_rows);
  std::iota(row_ids.begin(), row_ids.end(), 0);

  RETURN_NOT_OK(row_encoder.EncodeSelected(&row_table, static_cast<uint32_t>(num_rows),
                                           row_ids.data()));

  return row_table;
}

}  // namespace