Method EncodeSelected

cpp/src/arrow/compute/row/encode_internal.cc:153–191

}

Status RowTableEncoder::EncodeSelected(RowTableImpl* rows, uint32_t num_selected,
                                       const uint16_t* selection) {
  rows->Clean();

  // First AppendEmpty with num_selected rows and zero extra bytes to resize the
  // fixed-length buffers (including buffer for offsets).
  RETURN_NOT_OK(
      rows->AppendEmpty(static_cast<uint32_t>(num_selected),
                        /*num_extra_bytes_to_append=*/static_cast<uint32_t>(0)));
  // Then populate the offsets of the var-length columns, which will be used as the target
  // size of the var-length buffers resizing below.
  RETURN_NOT_OK(EncoderOffsets::GetRowOffsetsSelected(rows, batch_varbinary_cols_,
                                                      num_selected, selection));
  // Last AppendEmpty with zero rows and zero extra bytes to resize the var-length buffers
  // based on the populated offsets.
  RETURN_NOT_OK(
      rows->AppendEmpty(/*num_rows_to_append=*/static_cast<uint32_t>(0),
                        /*num_extra_bytes_to_append=*/static_cast<uint32_t>(0)));

  for (size_t icol = 0; icol < batch_all_cols_.size(); ++icol) {
    if (batch_all_cols_[icol].metadata().is_fixed_length) {
      uint32_t offset_within_row = rows->metadata().column_offsets[icol];
      EncoderBinary::EncodeSelected(offset_within_row, rows, batch_all_cols_[icol],
                                    num_selected, selection);
    }
  }

  EncoderOffsets::EncodeSelected(rows, batch_varbinary_cols_, num_selected, selection);

  for (size_t icol = 0; icol < batch_varbinary_cols_.size(); ++icol) {
    EncoderVarBinary::EncodeSelected(static_cast<uint32_t>(icol), rows,
                                     batch_varbinary_cols_[icol], num_selected,
                                     selection);
  }

  EncoderNulls::EncodeSelected(rows, batch_all_cols_, num_selected, selection);

  return Status::OK();
}

namespace {
struct TransformBoolean {