Start integrating StatsCounter class.

SampleCounter replaced with AvgCounter for metric WebRTC.Video.SendDelayInMs (removes duplicated code of SampleCounter).

BUG=webrtc:5283

Review-Url: https://codereview.webrtc.org/2013403002
Cr-Commit-Position: refs/heads/master@{#13081}

webrtc/video/send_delay_stats.cc

@@ -22,7 +22,7 @@ const size_t kMaxPacketMapSize = 2000;
 
 // Limit for the maximum number of streams to calculate stats for.
 const size_t kMaxSsrcMapSize = 50;
-const int kMinRequiredSamples = 200;
+const int kMinRequiredPeriodicSamples = 5;
 }  // namespace
 
 SendDelayStats::SendDelayStats(Clock* clock)
@@ -40,10 +40,10 @@ SendDelayStats::~SendDelayStats() {
 void SendDelayStats::UpdateHistograms() {
   rtc::CritScope lock(&crit_);
   for (const auto& it : send_delay_counters_) {
-    int send_delay_ms = it.second.Avg(kMinRequiredSamples);
-    if (send_delay_ms != -1) {
+    AggregatedStats stats = it.second->GetStats();
+    if (stats.num_samples >= kMinRequiredPeriodicSamples) {
       RTC_LOGGED_HISTOGRAM_COUNTS_10000("WebRTC.Video.SendDelayInMs",
-                                        send_delay_ms);
+                                        stats.average);
     }
   }
 }
@@ -56,6 +56,16 @@ void SendDelayStats::AddSsrcs(const VideoSendStream::Config& config) {
     ssrcs_.insert(ssrc);
 }
 
+AvgCounter* SendDelayStats::GetSendDelayCounter(uint32_t ssrc) {
+  const auto& it = send_delay_counters_.find(ssrc);
+  if (it != send_delay_counters_.end())
+    return it->second.get();
+
+  AvgCounter* counter = new AvgCounter(clock_, nullptr);
+  send_delay_counters_[ssrc].reset(counter);
+  return counter;
+}
+
 void SendDelayStats::OnSendPacket(uint16_t packet_id,
                                   int64_t capture_time_ms,
                                   uint32_t ssrc) {
@@ -88,7 +98,7 @@ bool SendDelayStats::OnSentPacket(int packet_id, int64_t time_ms) {
   // TODO(asapersson): Remove SendSideDelayUpdated(), use capture -> sent.
   // Elapsed time from send (to transport) -> sent (leaving socket).
   int diff_ms = time_ms - it->second.send_time_ms;
-  send_delay_counters_[it->second.ssrc].Add(diff_ms);
+  GetSendDelayCounter(it->second.ssrc)->Add(diff_ms);
   packets_.erase(it);
   return true;
 }
@@ -104,15 +114,4 @@ void SendDelayStats::RemoveOld(int64_t now, PacketMap* packets) {
   }
 }
 
-void SendDelayStats::SampleCounter::Add(int sample) {
-  sum += sample;
-  ++num_samples;
-}
-
-int SendDelayStats::SampleCounter::Avg(int min_required_samples) const {
-  if (num_samples < min_required_samples || num_samples == 0)
-    return -1;
-  return (sum + (num_samples / 2)) / num_samples;
-}
-
 }  // namespace webrtc

webrtc/video/send_delay_stats.h

@@ -20,6 +20,7 @@
 #include "webrtc/common_types.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/system_wrappers/include/clock.h"
+#include "webrtc/video/stats_counter.h"
 #include "webrtc/video_send_stream.h"
 
 namespace webrtc {
@@ -61,21 +62,11 @@ class SendDelayStats : public SendPacketObserver {
   };
   typedef std::map<uint16_t, Packet, SequenceNumberOlderThan> PacketMap;
 
-  class SampleCounter {
-   public:
-    SampleCounter() : sum(0), num_samples(0) {}
-    ~SampleCounter() {}
-    void Add(int sample);
-    int Avg(int min_required_samples) const;
-
-   private:
-    int sum;
-    int num_samples;
-  };
-
   void UpdateHistograms();
   void RemoveOld(int64_t now, PacketMap* packets)
       EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  AvgCounter* GetSendDelayCounter(uint32_t ssrc)
+      EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   Clock* const clock_;
   rtc::CriticalSection crit_;
@@ -85,8 +76,10 @@ class SendDelayStats : public SendPacketObserver {
   size_t num_skipped_packets_ GUARDED_BY(crit_);
 
   std::set<uint32_t> ssrcs_ GUARDED_BY(crit_);
-  std::map<uint32_t, SampleCounter> send_delay_counters_
-      GUARDED_BY(crit_);  // Mapped by SSRC.
+
+  // Mapped by SSRC.
+  std::map<uint32_t, std::unique_ptr<AvgCounter>> send_delay_counters_
+      GUARDED_BY(crit_);
 };
 
 }  // namespace webrtc

webrtc/video/send_delay_stats_unittest.cc

@@ -22,7 +22,8 @@ const uint32_t kRtxSsrc1 = 18;
 const uint32_t kRtxSsrc2 = 43;
 const uint16_t kPacketId = 2345;
 const int64_t kMaxPacketDelayMs = 11000;
-const int kMinRequiredSamples = 200;
+const int kMinRequiredPeriodicSamples = 5;
+const int kProcessIntervalMs = 2000;
 }  // namespace
 
 class SendDelayStatsTest : public ::testing::Test {
@@ -104,9 +105,12 @@ TEST_F(SendDelayStatsTest, OldPacketsRemoved) {
 TEST_F(SendDelayStatsTest, HistogramsAreUpdated) {
   metrics::Reset();
   const int64_t kDelayMs1 = 5;
-  const int64_t kDelayMs2 = 10;
+  const int64_t kDelayMs2 = 15;
+  const int kNumSamples = kMinRequiredPeriodicSamples * kProcessIntervalMs /
+                          (kDelayMs1 + kDelayMs2) + 1;
+
   uint16_t id = 0;
-  for (int i = 0; i < kMinRequiredSamples; ++i) {
+  for (int i = 0; i < kNumSamples; ++i) {
     OnSendPacket(++id, kSsrc1);
     clock_.AdvanceTimeMilliseconds(kDelayMs1);
     EXPECT_TRUE(OnSentPacket(id));