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/*
* Copyright (c) 2016 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 "video/stats_counter.h"
#include <algorithm>
#include <limits>
#include <map>
#include "rtc_base/checks.h"
#include "rtc_base/strings/string_builder.h"
#include "system_wrappers/include/clock.h"
namespace webrtc {
namespace {
// Default periodic time interval for processing samples.
const int64_t kDefaultProcessIntervalMs = 2000;
const uint32_t kStreamId0 = 0;
} // namespace
std::string AggregatedStats::ToString() const {
return ToStringWithMultiplier(1);
}
std::string AggregatedStats::ToStringWithMultiplier(int multiplier) const {
rtc::StringBuilder ss;
ss << "periodic_samples:" << num_samples << ", {";
ss << "min:" << (min * multiplier) << ", ";
ss << "avg:" << (average * multiplier) << ", ";
ss << "max:" << (max * multiplier) << "}";
return ss.Release();
}
// Class holding periodically computed metrics.
class AggregatedCounter {
public:
AggregatedCounter() : last_sample_(0), sum_samples_(0) {}
~AggregatedCounter() {}
void Add(int sample) {
last_sample_ = sample;
sum_samples_ += sample;
++stats_.num_samples;
if (stats_.num_samples == 1) {
stats_.min = sample;
stats_.max = sample;
}
stats_.min = std::min(sample, stats_.min);
stats_.max = std::max(sample, stats_.max);
}
AggregatedStats ComputeStats() {
Compute();
return stats_;
}
bool Empty() const { return stats_.num_samples == 0; }
int last_sample() const { return last_sample_; }
private:
void Compute() {
if (stats_.num_samples == 0)
return;
stats_.average =
(sum_samples_ + stats_.num_samples / 2) / stats_.num_samples;
}
int last_sample_;
int64_t sum_samples_;
AggregatedStats stats_;
};
// Class holding gathered samples within a process interval.
class Samples {
public:
Samples() : total_count_(0) {}
~Samples() {}
void Add(int sample, uint32_t stream_id) {
samples_[stream_id].Add(sample);
++total_count_;
}
void Set(int64_t sample, uint32_t stream_id) {
samples_[stream_id].Set(sample);
++total_count_;
}
void SetLast(int64_t sample, uint32_t stream_id) {
samples_[stream_id].SetLast(sample);
}
int64_t GetLast(uint32_t stream_id) { return samples_[stream_id].GetLast(); }
int64_t Count() const { return total_count_; }
bool Empty() const { return total_count_ == 0; }
int64_t Sum() const {
int64_t sum = 0;
for (const auto& it : samples_)
sum += it.second.sum_;
return sum;
}
int Max() const {
int max = std::numeric_limits<int>::min();
for (const auto& it : samples_)
max = std::max(it.second.max_, max);
return max;
}
void Reset() {
for (auto& it : samples_)
it.second.Reset();
total_count_ = 0;
}
int64_t Diff() const {
int64_t sum_diff = 0;
int count = 0;
for (const auto& it : samples_) {
if (it.second.count_ > 0) {
int64_t diff = it.second.sum_ - it.second.last_sum_;
if (diff >= 0) {
sum_diff += diff;
++count;
}
}
}
return (count > 0) ? sum_diff : -1;
}
private:
struct Stats {
void Add(int sample) {
sum_ += sample;
++count_;
max_ = std::max(sample, max_);
}
void Set(int64_t sample) {
sum_ = sample;
++count_;
}
void SetLast(int64_t sample) { last_sum_ = sample; }
int64_t GetLast() const { return last_sum_; }
void Reset() {
if (count_ > 0)
last_sum_ = sum_;
sum_ = 0;
count_ = 0;
max_ = std::numeric_limits<int>::min();
}
int max_ = std::numeric_limits<int>::min();
int64_t count_ = 0;
int64_t sum_ = 0;
int64_t last_sum_ = 0;
};
int64_t total_count_;
std::map<uint32_t, Stats> samples_; // Gathered samples mapped by stream id.
};
// StatsCounter class.
StatsCounter::StatsCounter(Clock* clock,
int64_t process_intervals_ms,
bool include_empty_intervals,
StatsCounterObserver* observer)
: include_empty_intervals_(include_empty_intervals),
process_intervals_ms_(process_intervals_ms),
aggregated_counter_(new AggregatedCounter()),
samples_(new Samples()),
clock_(clock),
observer_(observer),
last_process_time_ms_(-1),
paused_(false),
pause_time_ms_(-1),
min_pause_time_ms_(0) {
RTC_DCHECK_GT(process_intervals_ms_, 0);
}
StatsCounter::~StatsCounter() {}
AggregatedStats StatsCounter::GetStats() {
return aggregated_counter_->ComputeStats();
}
AggregatedStats StatsCounter::ProcessAndGetStats() {
if (HasSample())
TryProcess();
return aggregated_counter_->ComputeStats();
}
void StatsCounter::ProcessAndPauseForDuration(int64_t min_pause_time_ms) {
ProcessAndPause();
min_pause_time_ms_ = min_pause_time_ms;
}
void StatsCounter::ProcessAndPause() {
if (HasSample())
TryProcess();
paused_ = true;
pause_time_ms_ = clock_->TimeInMilliseconds();
}
void StatsCounter::ProcessAndStopPause() {
if (HasSample())
TryProcess();
Resume();
}
bool StatsCounter::HasSample() const {
return last_process_time_ms_ != -1;
}
bool StatsCounter::TimeToProcess(int* elapsed_intervals) {
int64_t now = clock_->TimeInMilliseconds();
if (last_process_time_ms_ == -1)
last_process_time_ms_ = now;
int64_t diff_ms = now - last_process_time_ms_;
if (diff_ms < process_intervals_ms_)
return false;
// Advance number of complete `process_intervals_ms_` that have passed.
int64_t num_intervals = diff_ms / process_intervals_ms_;
last_process_time_ms_ += num_intervals * process_intervals_ms_;
*elapsed_intervals = num_intervals;
return true;
}
void StatsCounter::Add(int sample) {
TryProcess();
samples_->Add(sample, kStreamId0);
ResumeIfMinTimePassed();
}
void StatsCounter::Set(int64_t sample, uint32_t stream_id) {
if (paused_ && sample == samples_->GetLast(stream_id)) {
// Do not add same sample while paused (will reset pause).
return;
}
TryProcess();
samples_->Set(sample, stream_id);
ResumeIfMinTimePassed();
}
void StatsCounter::SetLast(int64_t sample, uint32_t stream_id) {
RTC_DCHECK(!HasSample()) << "Should be set before first sample is added.";
samples_->SetLast(sample, stream_id);
}
// Reports periodically computed metric.
void StatsCounter::ReportMetricToAggregatedCounter(
int value,
int num_values_to_add) const {
for (int i = 0; i < num_values_to_add; ++i) {
aggregated_counter_->Add(value);
if (observer_)
observer_->OnMetricUpdated(value);
}
}
void StatsCounter::TryProcess() {
int elapsed_intervals;
if (!TimeToProcess(&elapsed_intervals))
return;
// Get and report periodically computed metric.
int metric;
if (GetMetric(&metric))
ReportMetricToAggregatedCounter(metric, 1);
// Report value for elapsed intervals without samples.
if (IncludeEmptyIntervals()) {
// If there are no samples, all elapsed intervals are empty (otherwise one
// interval contains sample(s), discard this interval).
int empty_intervals =
samples_->Empty() ? elapsed_intervals : (elapsed_intervals - 1);
ReportMetricToAggregatedCounter(GetValueForEmptyInterval(),
empty_intervals);
}
// Reset samples for elapsed interval.
samples_->Reset();
}
bool StatsCounter::IncludeEmptyIntervals() const {
return include_empty_intervals_ && !paused_ && !aggregated_counter_->Empty();
}
void StatsCounter::ResumeIfMinTimePassed() {
if (paused_ &&
(clock_->TimeInMilliseconds() - pause_time_ms_) >= min_pause_time_ms_) {
Resume();
}
}
void StatsCounter::Resume() {
paused_ = false;
min_pause_time_ms_ = 0;
}
// StatsCounter sub-classes.
AvgCounter::AvgCounter(Clock* clock,
StatsCounterObserver* observer,
bool include_empty_intervals)
: StatsCounter(clock,
kDefaultProcessIntervalMs,
include_empty_intervals,
observer) {}
void AvgCounter::Add(int sample) {
StatsCounter::Add(sample);
}
bool AvgCounter::GetMetric(int* metric) const {
int64_t count = samples_->Count();
if (count == 0)
return false;
*metric = (samples_->Sum() + count / 2) / count;
return true;
}
int AvgCounter::GetValueForEmptyInterval() const {
return aggregated_counter_->last_sample();
}
MaxCounter::MaxCounter(Clock* clock,
StatsCounterObserver* observer,
int64_t process_intervals_ms)
: StatsCounter(clock,
process_intervals_ms,
false, // `include_empty_intervals`
observer) {}
void MaxCounter::Add(int sample) {
StatsCounter::Add(sample);
}
bool MaxCounter::GetMetric(int* metric) const {
if (samples_->Empty())
return false;
*metric = samples_->Max();
return true;
}
int MaxCounter::GetValueForEmptyInterval() const {
RTC_DCHECK_NOTREACHED();
return 0;
}
PercentCounter::PercentCounter(Clock* clock, StatsCounterObserver* observer)
: StatsCounter(clock,
kDefaultProcessIntervalMs,
false, // `include_empty_intervals`
observer) {}
void PercentCounter::Add(bool sample) {
StatsCounter::Add(sample ? 1 : 0);
}
bool PercentCounter::GetMetric(int* metric) const {
int64_t count = samples_->Count();
if (count == 0)
return false;
*metric = (samples_->Sum() * 100 + count / 2) / count;
return true;
}
int PercentCounter::GetValueForEmptyInterval() const {
RTC_DCHECK_NOTREACHED();
return 0;
}
PermilleCounter::PermilleCounter(Clock* clock, StatsCounterObserver* observer)
: StatsCounter(clock,
kDefaultProcessIntervalMs,
false, // `include_empty_intervals`
observer) {}
void PermilleCounter::Add(bool sample) {
StatsCounter::Add(sample ? 1 : 0);
}
bool PermilleCounter::GetMetric(int* metric) const {
int64_t count = samples_->Count();
if (count == 0)
return false;
*metric = (samples_->Sum() * 1000 + count / 2) / count;
return true;
}
int PermilleCounter::GetValueForEmptyInterval() const {
RTC_DCHECK_NOTREACHED();
return 0;
}
RateCounter::RateCounter(Clock* clock,
StatsCounterObserver* observer,
bool include_empty_intervals)
: StatsCounter(clock,
kDefaultProcessIntervalMs,
include_empty_intervals,
observer) {}
void RateCounter::Add(int sample) {
StatsCounter::Add(sample);
}
bool RateCounter::GetMetric(int* metric) const {
if (samples_->Empty())
return false;
*metric = (samples_->Sum() * 1000 + process_intervals_ms_ / 2) /
process_intervals_ms_;
return true;
}
int RateCounter::GetValueForEmptyInterval() const {
return 0;
}
RateAccCounter::RateAccCounter(Clock* clock,
StatsCounterObserver* observer,
bool include_empty_intervals)
: StatsCounter(clock,
kDefaultProcessIntervalMs,
include_empty_intervals,
observer) {}
void RateAccCounter::Set(int64_t sample, uint32_t stream_id) {
StatsCounter::Set(sample, stream_id);
}
void RateAccCounter::SetLast(int64_t sample, uint32_t stream_id) {
StatsCounter::SetLast(sample, stream_id);
}
bool RateAccCounter::GetMetric(int* metric) const {
int64_t diff = samples_->Diff();
if (diff < 0 || (!include_empty_intervals_ && diff == 0))
return false;
*metric = (diff * 1000 + process_intervals_ms_ / 2) / process_intervals_ms_;
return true;
}
int RateAccCounter::GetValueForEmptyInterval() const {
return 0;
}
} // namespace webrtc