Function padding_for_alignment_within_row

cpp/src/arrow/compute/row/row_internal.h:87–92

Rounding up offset within row to the nearest multiple of alignment value. Alignment must be a power of 2.

  /// Rounding up offset within row to the nearest multiple of alignment value.
  /// Alignment must be a power of 2.
  static inline uint32_t padding_for_alignment_within_row(uint32_t offset,
                                                          int required_alignment) {
    ARROW_DCHECK(std::popcount(static_cast<uint64_t>(required_alignment)) == 1);
    return static_cast<uint32_t>((-static_cast<int32_t>(offset)) &
                                 (required_alignment - 1));
  }

  /// Rounding up offset within row to the beginning of next column,
  /// choosing required alignment based on the data type of that column.