benchmark.cc

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#include "ion/analytics/benchmark.h"

#include <algorithm>
#include <chrono>  // NOLINT
#include <limits>

#include "ion/math/utils.h"

namespace ion {
namespace analytics {




void Benchmark::VariableSampler::AddSample(double value) {
  if (variable_.samples.empty()) {
    timer_.Reset();
    variable_.samples.push_back(Sample(0, value));
  } else {
    variable_.samples.push_back(Sample(
        std::chrono::duration_cast<std::chrono::duration<uint32, std::milli>>(
            timer_.Get())
            .count(),
        value));
  }
}




Benchmark::VariableAccumulator::VariableAccumulator(
    const Descriptor& descriptor)
    : variable_(descriptor, 0,
                std::numeric_limits<double>::max(),
                std::numeric_limits<double>::min(),
                0.0, 0.0),
      m2_(0.0) {
}

void Benchmark::VariableAccumulator::AddSample(double value) {
  ++variable_.samples;
  variable_.minimum = std::min(variable_.minimum, value);
  variable_.maximum = std::max(variable_.maximum, value);

  const double delta = value - variable_.mean;
  variable_.mean += delta / static_cast<double>(variable_.samples);
  m2_ += delta * (value - variable_.mean);
}

const Benchmark::AccumulatedVariable Benchmark::VariableAccumulator::Get() {
  variable_.standard_deviation =
      variable_.samples ?
      math::Sqrt(m2_ / static_cast<double>(variable_.samples - 1U)) : 0.0;

  return variable_;
}




const Benchmark::AccumulatedVariable Benchmark::AccumulateSampledVariable(
    const Benchmark::SampledVariable& sampled_variable) {
  VariableAccumulator va(sampled_variable.descriptor);
  const size_t num_samples = sampled_variable.samples.size();
  for (size_t i = 0; i < num_samples; ++i)
    va.AddSample(sampled_variable.samples[i].value);
  return va.Get();
}

}  // namespace analytics
}  // namespace ion