Function RowArrayDecodeBenchmark

cpp/src/arrow/acero/hash_join_benchmark.cc:666–697

#endif  // ARROW_BUILD_DETAILED_BENCHMARKS

void RowArrayDecodeBenchmark(benchmark::State& st, const std::shared_ptr<Schema>& schema,
                             int column_to_decode) {
  auto batches = MakeRandomBatches(schema, 1, std::numeric_limits<uint16_t>::max());
  const auto& batch = batches.batches[0];
  RowArray rows;
  std::vector<uint16_t> row_ids_encode(batch.length);
  std::iota(row_ids_encode.begin(), row_ids_encode.end(), 0);
  std::vector<KeyColumnArray> temp_column_arrays;
  DCHECK_OK(rows.AppendBatchSelection(
      default_memory_pool(), internal::CpuInfo::GetInstance()->hardware_flags(), batch, 0,
      static_cast<int>(batch.length), static_cast<int>(batch.length),
      row_ids_encode.data(), temp_column_arrays));
  std::vector<uint32_t> row_ids_decode(batch.length);
  // Create a random access pattern to simulate hash join.
  std::default_random_engine gen(42);
  std::uniform_int_distribution<uint32_t> dist(0,
                                               static_cast<uint32_t>(batch.length - 1));
  std::transform(row_ids_decode.begin(), row_ids_decode.end(), row_ids_decode.begin(),
                 [&](uint32_t) { return dist(gen); });

  for (auto _ : st) {
    ResizableArrayData column;
    // Allocate at least 8 rows for the convenience of SIMD decoding.
    int log_num_rows_min = std::max(3, bit_util::Log2(batch.length));
    DCHECK_OK(column.Init(batch[column_to_decode].type(), default_memory_pool(),
                          log_num_rows_min));
    DCHECK_OK(rows.DecodeSelected(&column, column_to_decode,
                                  static_cast<int>(batch.length), row_ids_decode.data(),
                                  default_memory_pool()));
  }
  st.SetItemsProcessed(st.iterations() * batch.length);
}

static void BM_RowArray_Decode(benchmark::State& st,
                               const std::shared_ptr<DataType>& type) {