Take smaller interface for RtpRtcp::Configuration::receive_statistics

webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc

Index: webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc
diff --git a/webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc b/webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc
index fe5f02b45b71237e720b1325fc0cfc16f920a1fd..21f5b37c2f5cf26dd8011a2c4b5ec0b0ef350711 100644
--- a/webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc
+++ b/webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc
@@ -13,10 +13,12 @@
 #include <math.h>
 
 #include <cstdlib>
+#include <vector>
 
 #include "webrtc/modules/remote_bitrate_estimator/test/bwe_test_logging.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_rtcp_config.h"
 #include "webrtc/modules/rtp_rtcp/source/time_util.h"
+#include "webrtc/rtc_base/logging.h"
 #include "webrtc/system_wrappers/include/clock.h"
 
 namespace webrtc {
@@ -492,6 +494,37 @@ void ReceiveStatisticsImpl::DataCountersUpdated(const StreamDataCounters& stats,
   }
 }
 
+std::vector<rtcp::ReportBlock> ReceiveStatistics::RtcpReportBlocks(
+    size_t max_blocks) {
+  StatisticianMap statisticians = GetActiveStatisticians();
+  std::vector<rtcp::ReportBlock> result;
+  result.reserve(std::min(max_blocks, statisticians.size()));
+  for (auto& statistician : statisticians) {
+    // TODO(danilchap): Select statistician subset across multiple calls using
+    // round-robin, as described in rfc3550 section 6.4 when single
+    // rtcp_module/receive_statistics will be used for more rtp streams.
+    if (result.size() == max_blocks)
+      break;
+
+    // Do we have receive statistics to send?
+    RtcpStatistics stats;
+    if (!statistician.second->GetStatistics(&stats, true))
+      continue;
+    result.emplace_back();
+    rtcp::ReportBlock& block = result.back();
+    block.SetMediaSsrc(statistician.first);
+    block.SetFractionLost(stats.fraction_lost);
+    if (!block.SetCumulativeLost(stats.cumulative_lost)) {
+      LOG(LS_WARNING) << "Cumulative lost is oversized.";

[eladalon, 2017/07/27 09:07:31]

Would logging the value be useful?

[danilchap, 2017/07/27 10:04:32]

may be. I have a TODO in ReceiveStatistics to handle oversized values better,
but since it is theoretical issue so far, didn't put much thoughts into it.
(i.e. it is out of scope of this CL)

+      result.pop_back();
+      continue;
+    }
+    block.SetExtHighestSeqNum(stats.extended_max_sequence_number);
+    block.SetJitter(stats.jitter);
+  }
+  return result;
+}
+
 void NullReceiveStatistics::IncomingPacket(const RTPHeader& rtp_header,
                                            size_t packet_length,
                                            bool retransmitted) {}