Camera: Add metrics collection for FPS range

- Add new misc analytics flag for 24q3
- Add collection of most common FPS range requested by client
- Add tests for FPS histogram
  - Clean up unit test build files so that a source file doesn't have to be
    listed twice

Bug: 324485285
Test: New unit tests pass, camera CTS, manual checking of new metrics logging
Change-Id: I0e76b0f7c4a2e41e2a160051bba12d54e6fd480b
diff --git a/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.cpp b/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.cpp
index 65e93a9..4afae9b 100644
--- a/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.cpp
+++ b/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.cpp
@@ -95,7 +95,8 @@
         sp<hardware::ICameraServiceProxy>& proxyBinder,
         int64_t requestCount, int64_t resultErrorCount, bool deviceError,
         const std::string& userTag, int32_t videoStabilizationMode, bool usedUltraWide,
-        bool usedZoomOverride, const std::vector<hardware::CameraStreamStats>& streamStats) {
+        bool usedZoomOverride, std::pair<int32_t, int32_t> mostRequestedFpsRange,
+        const std::vector<hardware::CameraStreamStats>& streamStats) {
     Mutex::Autolock l(mLock);
 
     mSessionStats.mNewCameraState = CameraSessionStats::CAMERA_STATE_IDLE;
@@ -106,6 +107,7 @@
     mSessionStats.mVideoStabilizationMode = videoStabilizationMode;
     mSessionStats.mUsedUltraWide = usedUltraWide;
     mSessionStats.mUsedZoomOverride = usedZoomOverride;
+    mSessionStats.mMostRequestedFpsRange = mostRequestedFpsRange;
     mSessionStats.mStreamStats = streamStats;
 
     updateProxyDeviceState(proxyBinder);
@@ -281,7 +283,8 @@
 void CameraServiceProxyWrapper::logIdle(const std::string& id,
         int64_t requestCount, int64_t resultErrorCount, bool deviceError,
         const std::string& userTag, int32_t videoStabilizationMode, bool usedUltraWide,
-        bool usedZoomOverride, const std::vector<hardware::CameraStreamStats>& streamStats) {
+        bool usedZoomOverride, std::pair<int32_t, int32_t> mostRequestedFpsRange,
+        const std::vector<hardware::CameraStreamStats>& streamStats) {
     std::shared_ptr<CameraSessionStatsWrapper> sessionStats;
     {
         Mutex::Autolock l(mLock);
@@ -294,8 +297,9 @@
     }
 
     ALOGV("%s: id %s, requestCount %" PRId64 ", resultErrorCount %" PRId64 ", deviceError %d"
-            ", userTag %s, videoStabilizationMode %d", __FUNCTION__, id.c_str(), requestCount,
-            resultErrorCount, deviceError, userTag.c_str(), videoStabilizationMode);
+            ", userTag %s, videoStabilizationMode %d, most common FPS [%d,%d]",
+            __FUNCTION__, id.c_str(), requestCount, resultErrorCount, deviceError, userTag.c_str(),
+            videoStabilizationMode, mostRequestedFpsRange.first, mostRequestedFpsRange.second);
     for (size_t i = 0; i < streamStats.size(); i++) {
         ALOGV("%s: streamStats[%zu]: w %d h %d, requestedCount %" PRId64 ", dropCount %"
                 PRId64 ", startTimeMs %d" ,
@@ -306,7 +310,8 @@
 
     sp<hardware::ICameraServiceProxy> proxyBinder = getCameraServiceProxy();
     sessionStats->onIdle(proxyBinder, requestCount, resultErrorCount, deviceError, userTag,
-            videoStabilizationMode, usedUltraWide, usedZoomOverride, streamStats);
+            videoStabilizationMode, usedUltraWide, usedZoomOverride,
+            mostRequestedFpsRange, streamStats);
 }
 
 void CameraServiceProxyWrapper::logOpen(const std::string& id, int facing,
diff --git a/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.h b/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.h
index 49b7a8c..b6a967f 100644
--- a/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.h
+++ b/services/camera/libcameraservice/utils/CameraServiceProxyWrapper.h
@@ -62,7 +62,8 @@
         void onIdle(sp<hardware::ICameraServiceProxy>& proxyBinder,
                 int64_t requestCount, int64_t resultErrorCount, bool deviceError,
                 const std::string& userTag, int32_t videoStabilizationMode, bool usedUltraWide,
-                bool usedZoomOverride, const std::vector<hardware::CameraStreamStats>& streamStats);
+                bool usedZoomOverride, std::pair<int32_t, int32_t> mostRequestedFpsRange,
+                const std::vector<hardware::CameraStreamStats>& streamStats);
 
         std::string updateExtensionSessionStats(
                 const hardware::CameraExtensionSessionStats& extStats);
@@ -111,7 +112,8 @@
     void logIdle(const std::string& id,
             int64_t requestCount, int64_t resultErrorCount, bool deviceError,
             const std::string& userTag, int32_t videoStabilizationMode, bool usedUltraWide,
-            bool usedZoomOverride, const std::vector<hardware::CameraStreamStats>& streamStats);
+            bool usedZoomOverride, std::pair<int32_t, int32_t> mostRequestedFpsRange,
+            const std::vector<hardware::CameraStreamStats>& streamStats);
 
     // Ping camera service proxy for user update
     void pingCameraServiceProxy();
diff --git a/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp b/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
index c3aac72..2bca4cb 100644
--- a/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
+++ b/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
@@ -48,19 +48,35 @@
 
 void SessionStatsBuilder::buildAndReset(int64_t* requestCount,
         int64_t* errorResultCount, bool* deviceError,
-        std::map<int, StreamStats> *statsMap) {
+        std::pair<int32_t, int32_t>* mostRequestedFpsRange,
+        std::map<int, StreamStats>* statsMap) {
     std::lock_guard<std::mutex> l(mLock);
     *requestCount = mRequestCount;
     *errorResultCount = mErrorResultCount;
     *deviceError = mDeviceError;
     *statsMap = mStatsMap;
 
+    int32_t minFps = 0, maxFps = 0;
+    if (mRequestedFpsRangeHistogram.size() > 0) {
+        auto mostCommonIt = mRequestedFpsRangeHistogram.begin();
+        for (auto it = mostCommonIt; it != mRequestedFpsRangeHistogram.end(); it++) {
+            if (it->second.first > mostCommonIt->second.first) {
+                mostCommonIt = it;
+            }
+        }
+        minFps = mostCommonIt->first >> 32;
+        maxFps = mostCommonIt->first & 0xFFFF'FFFFU;
+    }
+    *mostRequestedFpsRange = std::make_pair(minFps, maxFps);
+
     // Reset internal states
     mRequestCount = 0;
     mErrorResultCount = 0;
     mCounterStopped = false;
     mDeviceError = false;
     mUserTag.clear();
+    mRequestedFpsRangeHistogram.clear();
+
     for (auto& streamStats : mStatsMap) {
         StreamStats& streamStat = streamStats.second;
         streamStat.mRequestedFrameCount = 0;
@@ -125,6 +141,31 @@
     mDeviceError = true;
 }
 
+void SessionStatsBuilder::incFpsRequestedCount(int32_t minFps, int32_t maxFps,
+        int64_t frameNumber) {
+    std::lock_guard<std::mutex> l(mLock);
+
+    // Stuff range into a 64-bit value to make hashing simple
+    uint64_t currentFpsTarget = minFps;
+    currentFpsTarget = currentFpsTarget << 32 | maxFps;
+
+    auto &stats = mRequestedFpsRangeHistogram[currentFpsTarget];
+    stats.first++;
+    stats.second = frameNumber;
+
+    // Ensure weird app input of target FPS ranges doesn't cause unbounded memory growth
+    if (mRequestedFpsRangeHistogram.size() > FPS_HISTOGRAM_MAX_SIZE) {
+        // Find oldest used fps to drop by last seen frame number
+        auto deleteIt = mRequestedFpsRangeHistogram.begin();
+        for (auto it = deleteIt; it != mRequestedFpsRangeHistogram.end(); it++) {
+            if (it->second.second < deleteIt->second.second) {
+                deleteIt = it;
+            }
+        }
+        mRequestedFpsRangeHistogram.erase(deleteIt);
+    }
+}
+
 void StreamStats::updateLatencyHistogram(int32_t latencyMs) {
     size_t i;
     for (i = 0; i < mCaptureLatencyBins.size(); i++) {
diff --git a/services/camera/libcameraservice/utils/SessionStatsBuilder.h b/services/camera/libcameraservice/utils/SessionStatsBuilder.h
index 2936531..914c09e 100644
--- a/services/camera/libcameraservice/utils/SessionStatsBuilder.h
+++ b/services/camera/libcameraservice/utils/SessionStatsBuilder.h
@@ -22,6 +22,8 @@
 #include <array>
 #include <map>
 #include <mutex>
+#include <unordered_map>
+#include <utility>
 
 namespace android {
 
@@ -64,7 +66,8 @@
     void buildAndReset(/*out*/int64_t* requestCount,
             /*out*/int64_t* errorResultCount,
             /*out*/bool* deviceError,
-            /*out*/std::map<int, StreamStats> *statsMap);
+            /*out*/std::pair<int32_t, int32_t>* mostRequestedFpsRange,
+            /*out*/std::map<int, StreamStats>* statsMap);
 
     // Stream specific counter
     void startCounter(int streamId);
@@ -76,6 +79,13 @@
     void incResultCounter(bool dropped);
     void onDeviceError();
 
+    // Session specific statistics
+
+    // Limit on size of FPS range histogram
+    static const size_t FPS_HISTOGRAM_MAX_SIZE = 10;
+
+    void incFpsRequestedCount(int32_t minFps, int32_t maxFps, int64_t frameNumber);
+
     SessionStatsBuilder() : mRequestCount(0), mErrorResultCount(0),
              mCounterStopped(false), mDeviceError(false) {}
 private:
@@ -85,6 +95,11 @@
     bool mCounterStopped;
     bool mDeviceError;
     std::string mUserTag;
+
+    // Histogram of frame counts of requested target FPS ranges
+    // (min_fps << 32 | max_fps) -> (# of frames with this fps, last seen framenumber)
+    std::unordered_map<uint64_t, std::pair<int64_t, int64_t>> mRequestedFpsRangeHistogram;
+
     // Map from stream id to stream statistics
     std::map<int, StreamStats> mStatsMap;
 };