void tdigest_timing_profile::run()

in cpp/src/tdigest_merge_timing_profile_impl.hpp [39:96]

• 38 lines of code
• 5 McCabe index (conditional complexity)

void tdigest_timing_profile<T>::run() {
  const size_t lg_min_stream_len(0);
  const size_t lg_max_stream_len(23);
  const size_t ppo(16);

  const size_t lg_max_trials(16);
  const size_t lg_min_trials(6);

  const size_t num_queries(20);

  std::cout << "Stream\tTrials\tBuild\tUpdate\tRank" << std::endl;

  std::vector<T> values(1ULL << lg_max_stream_len, 0);

  std::vector<T> rank_query_values(num_queries, 0);
  for (size_t i = 0; i < num_queries; i++) rank_query_values[i] = sample();

  size_t stream_length(1 << lg_min_stream_len);
  while (stream_length <= (1 << lg_max_stream_len)) {

    std::chrono::nanoseconds build_time_ns(0);
    std::chrono::nanoseconds update_time_ns(0);
    std::chrono::nanoseconds get_rank_time_ns(0);
    size_t size_bytes = 0;

    const size_t num_trials = get_num_trials(stream_length, lg_min_stream_len, lg_max_stream_len, lg_min_trials, lg_max_trials);
    for (size_t t = 0; t < num_trials; ++t) {
      std::generate(values.begin(), values.begin() + stream_length, [this] { return this->sample(); });

      auto start_build(std::chrono::high_resolution_clock::now());
      tdigest<T> sketch;
      auto finish_build(std::chrono::high_resolution_clock::now());
      build_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_build - start_build);

      auto start_update(std::chrono::high_resolution_clock::now());
      for (size_t i = 0; i < stream_length; ++i) sketch.update(values[i]);
      auto finish_update(std::chrono::high_resolution_clock::now());
      update_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_update - start_update);

//      auto start_get_rank(std::chrono::high_resolution_clock::now());
//      for (size_t i = 0; i < num_queries; i++) {
//        volatile double rank = sketch.get_rank(rank_query_values[i]); // volatile to prevent this from being optimized away
//      }
//      auto finish_get_rank(std::chrono::high_resolution_clock::now());
//      get_rank_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_get_rank - start_get_rank);

      size_bytes += sketch.get_serialized_size_bytes();
    }
    std::cout << stream_length << "\t"
        << num_trials << "\t"
        << (double) build_time_ns.count() / num_trials << "\t"
        << (double) update_time_ns.count() / num_trials / stream_length << "\t"
//        << (double) get_rank_time_ns.count() / num_trials / num_queries << "\t"
        << (double) size_bytes / num_trials << "\n";

    stream_length = pwr_2_law_next(ppo, stream_length);
  }
}