1 files changed, 463 insertions, 0 deletions
diff --git a/third_party/libwebrtc/video/stats_counter.cc b/third_party/libwebrtc/video/stats_counter.cc
new file mode 100644
index 0000000000..dc548ea3c3
--- /dev/null
+++ b/third_party/libwebrtc/video/stats_counter.cc
@@ -0,0 +1,463 @@
+/*
+ *  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