blob: ac077348e67d5b3f9bcfbaa0c9fbcc5ef5c72c0b [file] [log] [blame]
/*
* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/numerics/samples_stats_counter.h"
#include <algorithm>
#include <cmath>
namespace webrtc {
SamplesStatsCounter::SamplesStatsCounter() = default;
SamplesStatsCounter::~SamplesStatsCounter() = default;
SamplesStatsCounter::SamplesStatsCounter(SamplesStatsCounter&) = default;
SamplesStatsCounter::SamplesStatsCounter(SamplesStatsCounter&&) = default;
void SamplesStatsCounter::AddSample(double value) {
samples_.push_back(value);
sorted_ = false;
if (value > max_) {
max_ = value;
}
if (value < min_) {
min_ = value;
}
sum_ += value;
}
double SamplesStatsCounter::GetPercentile(double percentile) {
RTC_DCHECK(!IsEmpty());
RTC_CHECK_GE(percentile, 0);
RTC_CHECK_LE(percentile, 1);
if (!sorted_) {
std::sort(samples_.begin(), samples_.end());
sorted_ = true;
}
const double raw_rank = percentile * (samples_.size() - 1);
double int_part;
double fract_part = std::modf(raw_rank, &int_part);
size_t rank = static_cast<size_t>(int_part);
if (fract_part >= 1.0) {
// It can happen due to floating point calculation error.
rank++;
fract_part -= 1.0;
}
RTC_DCHECK_GE(rank, 0);
RTC_DCHECK_LT(rank, samples_.size());
RTC_DCHECK_GE(fract_part, 0);
RTC_DCHECK_LT(fract_part, 1);
RTC_DCHECK(rank + fract_part == raw_rank);
const double low = samples_[rank];
const double high = samples_[std::min(rank + 1, samples_.size() - 1)];
return low + fract_part * (high - low);
}
} // namespace webrtc