Method DecodeFixedLength

cpp/src/arrow/acero/swiss_join.cc:286–346

}

void RowArray::DecodeFixedLength(ResizableArrayData* output, int output_start_row,
                                 int column_id, uint32_t fixed_length,
                                 int num_rows_to_append, const uint32_t* row_ids) const {
  switch (fixed_length) {
    case 0:
      RowArrayAccessor::Visit(rows_, column_id, num_rows_to_append, row_ids,
                              [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
                                bit_util::SetBitTo(output->mutable_data(1),
                                                   output_start_row + i, *ptr != 0);
                              });
      break;
    case 1:
      RowArrayAccessor::Visit(rows_, column_id, num_rows_to_append, row_ids,
                              [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
                                output->mutable_data(1)[output_start_row + i] = *ptr;
                              });
      break;
    case 2:
      RowArrayAccessor::Visit(
          rows_, column_id, num_rows_to_append, row_ids,
          [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
            output->mutable_data_as<uint16_t>(1)[output_start_row + i] =
                *reinterpret_cast<const uint16_t*>(ptr);
          });
      break;
    case 4:
      RowArrayAccessor::Visit(
          rows_, column_id, num_rows_to_append, row_ids,
          [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
            output->mutable_data_as<uint32_t>(1)[output_start_row + i] =
                *reinterpret_cast<const uint32_t*>(ptr);
          });
      break;
    case 8:
      RowArrayAccessor::Visit(
          rows_, column_id, num_rows_to_append, row_ids,
          [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
            output->mutable_data_as<uint64_t>(1)[output_start_row + i] =
                *reinterpret_cast<const uint64_t*>(ptr);
          });
      break;
    default:
      RowArrayAccessor::Visit(
          rows_, column_id, num_rows_to_append, row_ids,
          [&](int i, const uint8_t* ptr, uint32_t num_bytes) {
            uint64_t* dst = reinterpret_cast<uint64_t*>(
                output->mutable_data(1) + num_bytes * (output_start_row + i));
            const uint64_t* src = reinterpret_cast<const uint64_t*>(ptr);
            // Note that both `output` and `ptr` have been allocated with enough padding
            // to accommodate the memory overshoot. See the allocations for
            // `ResizableArrayData` in `JoinResultMaterialize` and `JoinResidualFilter`
            // for `output`, and `RowTableImpl::kPaddingForVectors` for `ptr`.
            for (uint32_t word_id = 0;
                 word_id < bit_util::CeilDiv(num_bytes, sizeof(uint64_t)); ++word_id) {
              arrow::util::SafeStore<uint64_t>(dst + word_id,
                                               arrow::util::SafeLoad(src + word_id));
            }
          });