// Copyright 2020 Google LLC. All Rights Reserved.

#ifndef WHITEBOX_BENCHMARKING_MEASUREMENT_H_
#define WHITEBOX_BENCHMARKING_MEASUREMENT_H_

#include <stddef.h>
#include <stdint.h>

#include <algorithm>
#include <chrono>
#include <string>
#include <vector>

namespace widevine {

using Clock = std::chrono::high_resolution_clock;
using Period = std::chrono::microseconds;

class Timer {
 public:
  void Reset();

  Period Get() const;

 private:
  Clock::time_point start_;
};

struct Throughput {
  size_t bytes;
  uint64_t microseconds;
  uint64_t bits_per_second;

  Throughput();
  Throughput(const Period& duration, size_t bytes);
};

class Sampler {
 public:
  class Percentile {
   public:
    Percentile(const std::vector<Period>& samples) : samples_(samples) {
      std::sort(samples_.begin(), samples_.end());
    };

    const Period& Get(size_t percentile) const;

   private:
    std::vector<Period> samples_;
  };

  void Push(const Period& period);

  Percentile Percentiles() const { return Percentile(samples_); }

  size_t SampleSize() const { return samples_.size(); }

 private:
  std::vector<Period> samples_;
};

void PrettyPrint(const std::string& title,
                 const Throughput& throughput,
                 size_t bytes_per_call);

void PrettyPrint(const std::string& title,
                 const Sampler& samples,
                 size_t sample_input_size);

}  // namespace widevine

#endif  // WHITEBOX_BENCHMARKING_MEASUREMENT_H_