void hll_sketch_timing_profile::run()

in cpp/src/hll_sketch_timing_profile.cpp [30:109]

• 61 lines of code
• 8 McCabe index (conditional complexity)

void hll_sketch_timing_profile::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 = 17;
  const size_t lg_min_trials = 10;

  const size_t lg_k = 12;

  // some arbitrary starting value
  uint64_t counter = 35538947;

  const uint64_t golden64 = 0x9e3779b97f4a7c13ULL;  // the golden ratio

  std::cout << "Stream\tTrials\tBuild\tUpdate\tSer\tDeser\tSize" << std::endl;

  std::unique_ptr<hll_sketch> sketches[1 << lg_max_trials];

  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 serialize_time_ns(0);
    std::chrono::nanoseconds deserialize_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);

    const auto start_build(std::chrono::high_resolution_clock::now());
    for (size_t i = 0; i < num_trials; i++) {
      sketches[i] = std::unique_ptr<hll_sketch>(new hll_sketch(lg_k));
    }
    const auto finish_build(std::chrono::high_resolution_clock::now());
    build_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_build - start_build);

    const auto start_update(std::chrono::high_resolution_clock::now());
    for (size_t i = 0; i < num_trials; i++) {
      for (size_t j = 0; j < stream_length; j++) {
        sketches[i]->update(counter);
        counter += golden64;
      }
    }
    const auto finish_update(std::chrono::high_resolution_clock::now());
    update_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_update - start_update);

    //std::stringstream s(std::ios::in | std::ios::out | std::ios::binary);
    std::vector<std::vector<uint8_t>> bytes(num_trials);
    auto start_serialize(std::chrono::high_resolution_clock::now());
    for (size_t i = 0; i < num_trials; i++) {
      bytes[i] = sketches[i]->serialize_compact();
    }
    const auto finish_serialize(std::chrono::high_resolution_clock::now());
    serialize_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_serialize - start_serialize);

    const auto start_deserialize(std::chrono::high_resolution_clock::now());
    for (size_t i = 0; i < num_trials; i++) {
      auto deserialized_sketch = hll_sketch::deserialize(bytes[i].data(), bytes[i].size());
    }
    const auto finish_deserialize(std::chrono::high_resolution_clock::now());
    deserialize_time_ns += std::chrono::duration_cast<std::chrono::nanoseconds>(finish_deserialize - start_deserialize);

    //size_bytes += s.tellp();
    for (size_t i = 0; i < num_trials; i++) {
      size_bytes += bytes[i].size();
    }

    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) serialize_time_ns.count() / num_trials << "\t"
        << (double) deserialize_time_ns.count() / num_trials << "\t"
        << (double) size_bytes / num_trials << "\t"
        << std::endl;
    stream_length = pwr_2_law_next(ppo, stream_length);
  }

}