Report networking statistics along with GameReporter

 - jitter max, mean, variance

Source/Core/Core/HW/EXI_DeviceSlippi.cpp

@@ -2206,8 +2206,8 @@ void CEXISlippi::prepareNewSeed()
 
 void CEXISlippi::handleReportGame(u8 *payload)
 {
-	SlippiGameReporter::GameReport r;
-	r.durationFrames = Common::swap32(&payload[0]);
+	SlippiGameReporter::GameReport report;
+	report.durationFrames = Common::swap32(&payload[0]);
 
 	//ERROR_LOG(SLIPPI_ONLINE, "Frames: %d", r.durationFrames);
 
@@ -2222,10 +2222,13 @@ void CEXISlippi::handleReportGame(u8 *payload)
 
 		//ERROR_LOG(SLIPPI_ONLINE, "Stocks: %d, DamageDone: %f", p.stocksRemaining, p.damageDone);
 
-		r.players.push_back(p);
+		report.players.push_back(p);
 	}
 
-	gameReporter->StartReport(r);
+	// Add network quality information to game report
+	slippi_netplay->GetNetworkingStats(&report);
+
+	gameReporter->StartReport(report);
 }
 
 void CEXISlippi::DMAWrite(u32 _uAddr, u32 _uSize)

Source/Core/Core/Slippi/SlippiGameReporter.cpp

@@ -106,6 +106,9 @@ void SlippiGameReporter::ReportThreadHandler()
 			request["playKey"] = userInfo.playKey;
 			request["gameIndex"] = gameIndex;
 			request["gameDurationFrames"] = report.durationFrames;
+			request["jitterMean"] = report.jitterMean;
+			request["jitterMax"] = report.jitterMax;
+			request["jitterVariance"] = report.jitterVariance;
 
 			json players = json::array();
 			for (int i = 0; i < report.players.size(); i++)
@@ -138,4 +141,4 @@ void SlippiGameReporter::ReportThreadHandler()
 			Common::SleepCurrentThread(0);
 		}
 	}
-}
+}

Source/Core/Core/Slippi/SlippiGameReporter.h

@@ -23,6 +23,9 @@ class SlippiGameReporter
 	{
 		u32 durationFrames = 0;
 		std::vector<PlayerReport> players;
+    float jitterMean = 0;
+    float jitterMax = 0;
+    float jitterVariance = 0;
 	};
 
 	SlippiGameReporter(SlippiUser *user);

Source/Core/Core/Slippi/SlippiNetplay.cpp

@@ -26,8 +26,10 @@
 #include <SlippiGame.h>
 #include <algorithm>
 #include <fstream>
+#include <math.h>
 #include <mbedtls/md5.h>
 #include <memory>
+#include <numeric>
 #include <thread>
 
 static std::mutex pad_mutex;
@@ -148,6 +150,13 @@ unsigned int SlippiNetplayClient::OnData(sf::Packet &packet)
 
 		u64 curTime = Common::Timer::GetTimeUs();
 
+		// 120 frames to let the game settle before measuring network quality
+		if (frame > 120)
+		{
+			std::lock_guard<std::recursive_mutex> lkq(packetTimestampsMutex);
+			packetTimestamps.push_back(curTime);
+		}
+
 		auto timing = lastFrameTiming;
 		if (!hasGameStarted)
 		{
@@ -536,6 +545,10 @@ void SlippiNetplayClient::StartSlippiGame()
 
 	// Reset ack timers
 	ackTimers.Clear();
+	{
+		std::lock_guard<std::recursive_mutex> lkq(packetTimestampsMutex);
+		packetTimestamps.clear();
+	}
 }
 
 void SlippiNetplayClient::SendConnectionSelected()
@@ -714,3 +727,36 @@ s32 SlippiNetplayClient::CalcTimeOffsetUs()
 
 	return sum / count;
 }
+
+// C++ seriously doesn't have a variance built-in. So we have to make our own
+float SlippiNetplayClient::ComputeSampleVariance(float mean, std::vector<u64>& numbers)
+{
+	if (numbers.size() <= 1)
+	  return 0;
+
+	float total = 0;
+	for(u64 i : numbers) {
+		total += pow((i - mean), 2);
+	}
+
+	return total / (numbers.size() - 1);
+}
+
+void SlippiNetplayClient::GetNetworkingStats(SlippiGameReporter::GameReport *report)
+{
+	std::vector<u64> differences;
+	{
+		std::lock_guard<std::recursive_mutex> lkq(packetTimestampsMutex);
+		differences.resize(packetTimestamps.size()-1);
+		std::adjacent_difference(packetTimestamps.begin(), packetTimestamps.end(), differences.begin());
+		// For absolutely no reason that I can gather, adjacent_difference puts an exta element at the front of the result vector. Remove it
+		differences.erase(differences.begin());
+	}
+	float sum = 0;
+	for (u64 i : differences) {
+		sum += i;
+	}
+	report->jitterMean = sum / (float)differences.size();
+	report->jitterMax = (float)*std::max_element(differences.begin(), differences.end());
+	report->jitterVariance = ComputeSampleVariance(report->jitterMean, differences);
+}

Source/Core/Core/Slippi/SlippiNetplay.h

@@ -11,6 +11,7 @@
 #include "Common/TraversalClient.h"
 #include "Core/NetPlayProto.h"
 #include "Core/Slippi/SlippiPad.h"
+#include "Core/Slippi/SlippiGameReporter.h"
 #include "InputCommon/GCPadStatus.h"
 #include <SFML/Network/Packet.hpp>
 #include <array>
@@ -123,6 +124,7 @@ class SlippiNetplayClient
 	u64 GetSlippiPing();
 	int32_t GetSlippiLatestRemoteFrame();
 	s32 CalcTimeOffsetUs();
+	void GetNetworkingStats(SlippiGameReporter::GameReport *outReport);
 
   protected:
 	struct
@@ -169,6 +171,9 @@ class SlippiNetplayClient
 
 	FrameTiming lastFrameTiming;
 	u64 pingUs;
+	std::vector<u64> packetTimestamps;
+	std::recursive_mutex packetTimestampsMutex;
+
 	std::deque<std::unique_ptr<SlippiPad>> localPadQueue;  // most recent inputs at start of deque
 	std::deque<std::unique_ptr<SlippiPad>> remotePadQueue; // most recent inputs at start of deque
 	Common::FifoQueue<FrameTiming, false> ackTimers;
@@ -184,6 +189,7 @@ class SlippiNetplayClient
 	unsigned int OnData(sf::Packet &packet);
 	void Send(sf::Packet &packet);
 	void Disconnect();
+	float ComputeSampleVariance(float mean, std::vector<u64>& numbers);
 
 	bool m_is_connected = false;