Add ability to handle data from multiple streams in RateAccCounter.

webrtc/video/stats_counter.cc

 /*
  *  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 "webrtc/video/stats_counter.h"
 
 #include <algorithm>
+#include <limits>
+#include <map>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/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
 
 // Class holding periodically computed metrics.
 class AggregatedCounter {
  public:
   AggregatedCounter() : last_sample_(0), sum_samples_(0) {}
   ~AggregatedCounter() {}
 
   void Add(int sample) {
     last_sample_ = sample;
@@ skipping 22 matching lines @@
       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(int sample, uint32_t stream_id) {
+    samples_[stream_id].Set(sample);
+    ++total_count_;
+  }
+
+  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(int sample) {
+      sum_ = sample;
+      ++count_;
+    }
+    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)
-    : max_(0),
-      sum_(0),
-      num_samples_(0),
-      last_sum_(0),
+    : include_empty_intervals_(include_empty_intervals),
+      process_intervals_ms_(process_intervals_ms),
       aggregated_counter_(new AggregatedCounter()),
-      process_intervals_ms_(process_intervals_ms),
+      samples_(new Samples()),
       clock_(clock),
-      include_empty_intervals_(include_empty_intervals),
       observer_(observer),
       last_process_time_ms_(-1),
       paused_(false) {
   RTC_DCHECK_GT(process_intervals_ms_, 0);
 }
 
 StatsCounter::~StatsCounter() {}
 
 AggregatedStats StatsCounter::GetStats() {
   return aggregated_counter_->ComputeStats();
@@ skipping 25 matching lines @@
     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::Set(int sample) {
+void StatsCounter::Set(int sample, uint32_t stream_id) {
   TryProcess();
-  ++num_samples_;
-  sum_ = sample;
+  samples_->Set(sample, stream_id);
   paused_ = false;
 }
 
 void StatsCounter::Add(int sample) {
   TryProcess();
-  ++num_samples_;
-  sum_ += sample;
-
-  if (num_samples_ == 1)
-    max_ = sample;
-  max_ = std::max(sample, max_);
+  samples_->Add(sample, kStreamId0);
   paused_ = false;
 }
 
 // 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 =
-        (num_samples_ == 0) ? elapsed_intervals : (elapsed_intervals - 1);
+        samples_->Empty() ? elapsed_intervals : (elapsed_intervals - 1);
     ReportMetricToAggregatedCounter(GetValueForEmptyInterval(),
                                     empty_intervals);
   }
 
   // Reset samples for elapsed interval.
-  if (num_samples_ > 0)
-    last_sum_ = sum_;
-  sum_ = 0;
-  max_ = 0;
-  num_samples_ = 0;
+  samples_->Reset();
 }
 
 bool StatsCounter::IncludeEmptyIntervals() const {
   return include_empty_intervals_ && !paused_ && !aggregated_counter_->Empty();
 }
 
 // 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 {
-  if (num_samples_ == 0)
+  int64_t count = samples_->Count();
+  if (count == 0)
     return false;
-  *metric = (sum_ + num_samples_ / 2) / num_samples_;
+
+  *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 (num_samples_ == 0)
+  if (samples_->Empty())
     return false;
-  *metric = max_;
+
+  *metric = samples_->Max();
   return true;
 }
 
 int MaxCounter::GetValueForEmptyInterval() const {
   RTC_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 {
-  if (num_samples_ == 0)
+  int64_t count = samples_->Count();
+  if (count == 0)
     return false;
-  *metric = (sum_ * 100 + num_samples_ / 2) / num_samples_;
+
+  *metric = (samples_->Sum() * 100 + count / 2) / count;
   return true;
 }
 
 int PercentCounter::GetValueForEmptyInterval() const {
   RTC_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 {
-  if (num_samples_ == 0)
+  int64_t count = samples_->Count();
+  if (count == 0)
     return false;
-  *metric = (sum_ * 1000 + num_samples_ / 2) / num_samples_;
+
+  *metric = (samples_->Sum() * 1000 + count / 2) / count;
   return true;
 }
 
 int PermilleCounter::GetValueForEmptyInterval() const {
   RTC_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 (num_samples_ == 0)
+  if (samples_->Empty())
     return false;
-  *metric = (sum_ * 1000 + process_intervals_ms_ / 2) / process_intervals_ms_;
+
+  *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(int sample) {
-  StatsCounter::Set(sample);
+void RateAccCounter::Set(int sample, uint32_t stream_id) {
+  StatsCounter::Set(sample, stream_id);
 }
 
 bool RateAccCounter::GetMetric(int* metric) const {
-  if (num_samples_ == 0 || last_sum_ > sum_)
+  int64_t diff = samples_->Diff();
+  if (diff < 0 || (!include_empty_intervals_ && diff == 0))
     return false;
-  *metric = ((sum_ - last_sum_) * 1000 + process_intervals_ms_ / 2) /
-            process_intervals_ms_;
+
+  *metric = (diff * 1000 + process_intervals_ms_ / 2) / process_intervals_ms_;
   return true;
 }
 
 int RateAccCounter::GetValueForEmptyInterval() const {
   return 0;
 }
 
 }  // namespace webrtc