Core/Analytics: add support for performance sampling

Samples are pushed to the analytics module every frame but only sent
once every ~15min. We send data for 100 frames at a time.

Source/Core/Core/Analytics.cpp

@@ -5,6 +5,7 @@
 #include <memory>
 #include <mutex>
 #include <string>
+#include <vector>
 
 #if defined(_WIN32)
 #include <windows.h>
@@ -20,6 +21,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/Random.h"
 #include "Common/StringUtil.h"
+#include "Common/Timer.h"
 #include "Common/Version.h"
 #include "Core/ConfigManager.h"
 #include "Core/HW/GCPad.h"
@@ -128,6 +130,71 @@ void DolphinAnalytics::ReportGameStart()
   Common::AnalyticsReportBuilder builder(m_per_game_builder);
   builder.AddData("type", "game-start");
   Send(builder);
+
+  InitializePerformanceSampling();
+}
+
+void DolphinAnalytics::ReportPerformanceInfo(PerformanceSample&& sample)
+{
+  if (ShouldStartPerformanceSampling())
+  {
+    m_sampling_performance_info = true;
+  }
+
+  if (m_sampling_performance_info)
+  {
+    m_performance_samples.emplace_back(std::move(sample));
+  }
+
+  if (m_performance_samples.size() >= NUM_PERFORMANCE_SAMPLES_PER_REPORT)
+  {
+    std::vector<u32> speed_times_1000(m_performance_samples.size());
+    std::vector<u32> num_prims(m_performance_samples.size());
+    std::vector<u32> num_draw_calls(m_performance_samples.size());
+    for (size_t i = 0; i < m_performance_samples.size(); ++i)
+    {
+      speed_times_1000[i] = static_cast<u32>(m_performance_samples[i].speed_ratio * 1000);
+      num_prims[i] = m_performance_samples[i].num_prims;
+      num_draw_calls[i] = m_performance_samples[i].num_draw_calls;
+    }
+
+    // The per game builder should already exist -- there is no way we can be reporting performance
+    // info without a game start event having been generated.
+    Common::AnalyticsReportBuilder builder(m_per_game_builder);
+    builder.AddData("type", "performance");
+    builder.AddData("speed", speed_times_1000);
+    builder.AddData("prims", num_prims);
+    builder.AddData("draw-calls", num_draw_calls);
+
+    Send(builder);
+
+    // Clear up and stop sampling until next time ShouldStartPerformanceSampling() says so.
+    m_performance_samples.clear();
+    m_sampling_performance_info = false;
+  }
+}
+
+void DolphinAnalytics::InitializePerformanceSampling()
+{
+  m_performance_samples.clear();
+  m_sampling_performance_info = false;
+
+  u64 wait_us =
+      PERFORMANCE_SAMPLING_INITIAL_WAIT_TIME_SECS * 1000000 +
+      Common::Random::GenerateValue<u64>() % (PERFORMANCE_SAMPLING_WAIT_TIME_JITTER_SECS * 1000000);
+  m_sampling_next_start_us = Common::Timer::GetTimeUs() + wait_us;
+}
+
+bool DolphinAnalytics::ShouldStartPerformanceSampling()
+{
+  if (Common::Timer::GetTimeUs() < m_sampling_next_start_us)
+    return false;
+
+  u64 wait_us =
+      PERFORMANCE_SAMPLING_INTERVAL_SECS * 1000000 +
+      Common::Random::GenerateValue<u64>() % (PERFORMANCE_SAMPLING_WAIT_TIME_JITTER_SECS * 1000000);
+  m_sampling_next_start_us = Common::Timer::GetTimeUs() + wait_us;
+  return true;
 }
 
 void DolphinAnalytics::MakeBaseBuilder()