Fireperf: use the new class FrameMetricsRecorder in AppStateMonitor and FragmentStateMonitor (#3683)

Author: leotianlizhan

firebase-perf/src/main/java/com/google/firebase/perf/application/AppStateMonitor.java

@@ -20,18 +20,18 @@
 import android.content.Context;
 import android.os.Bundle;
 import androidx.annotation.NonNull;
-import androidx.core.app.FrameMetricsAggregator;
 import androidx.fragment.app.FragmentActivity;
 import com.google.android.gms.common.util.VisibleForTesting;
 import com.google.firebase.perf.config.ConfigResolver;
 import com.google.firebase.perf.logging.AndroidLogger;
-import com.google.firebase.perf.metrics.FrameMetricsCalculator;
+import com.google.firebase.perf.metrics.FrameMetricsCalculator.PerfFrameMetrics;
 import com.google.firebase.perf.metrics.Trace;
 import com.google.firebase.perf.session.SessionManager;
 import com.google.firebase.perf.transport.TransportManager;
 import com.google.firebase.perf.util.Clock;
 import com.google.firebase.perf.util.Constants;
 import com.google.firebase.perf.util.Constants.CounterNames;
+import com.google.firebase.perf.util.Optional;
 import com.google.firebase.perf.util.ScreenTraceUtil;
 import com.google.firebase.perf.util.Timer;
 import com.google.firebase.perf.v1.ApplicationProcessState;
@@ -49,13 +49,16 @@
 public class AppStateMonitor implements ActivityLifecycleCallbacks {
 
   private static final AndroidLogger logger = AndroidLogger.getInstance();
-  private static final String FRAME_METRICS_AGGREGATOR_CLASSNAME =
-      "androidx.core.app.FrameMetricsAggregator";
 
   private static volatile AppStateMonitor instance;
-  private static boolean hasFrameMetricsAggregator = false;
 
   private final WeakHashMap<Activity, Boolean> activityToResumedMap = new WeakHashMap<>();
+  private final WeakHashMap<Activity, FrameMetricsRecorder> activityToRecorderMap =
+      new WeakHashMap<>();
+
+  // Map for holding the fragment state monitor to remove receiving the fragment state callbacks
+  private final WeakHashMap<Activity, FragmentStateMonitor> activityToFragmentStateMonitorMap =
+      new WeakHashMap<>();
   private final WeakHashMap<Activity, Trace> activityToScreenTraceMap = new WeakHashMap<>();
   private final Map<String, Long> metricToCountMap = new HashMap<>();
   private final Set<WeakReference<AppStateCallback>> appStateSubscribers = new HashSet<>();
@@ -67,8 +70,7 @@ public class AppStateMonitor implements ActivityLifecycleCallbacks {
   private final TransportManager transportManager;
   private final ConfigResolver configResolver;
   private final Clock clock;
-
-  private FrameMetricsAggregator frameMetricsAggregator;
+  private final boolean screenPerformanceRecordingSupported;
 
   private Timer resumeTime; // The time app comes to foreground
   private Timer stopTime; // The time app goes to background
@@ -94,18 +96,19 @@ public static AppStateMonitor getInstance() {
         transportManager,
         clock,
         ConfigResolver.getInstance(),
-        hasFrameMetricsAggregatorClass() ? new FrameMetricsAggregator() : null);
+        isScreenPerformanceRecordingSupported());
   }
 
+  @VisibleForTesting
   AppStateMonitor(
       TransportManager transportManager,
       Clock clock,
       ConfigResolver configResolver,
-      FrameMetricsAggregator frameMetricsAggregator) {
+      boolean screenPerformanceRecordingSupported) {
     this.transportManager = transportManager;
     this.clock = clock;
     this.configResolver = configResolver;
-    this.frameMetricsAggregator = frameMetricsAggregator;
+    this.screenPerformanceRecordingSupported = screenPerformanceRecordingSupported;
   }
 
   public synchronized void registerActivityLifecycleCallbacks(Context context) {
@@ -149,28 +152,64 @@ public void incrementTsnsCount(int value) {
     tsnsCount.addAndGet(value);
   }
 
-  @Override
-  public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
+  // Starts tracking the frame metrics for an activity.
+  private void startFrameMonitoring(Activity activity) {
     if (isScreenTraceSupported() && configResolver.isPerformanceMonitoringEnabled()) {
+      FrameMetricsRecorder recorder = new FrameMetricsRecorder(activity);
+      activityToRecorderMap.put(activity, recorder);
       if (activity instanceof FragmentActivity) {
+        FragmentStateMonitor fragmentStateMonitor =
+            new FragmentStateMonitor(clock, transportManager, this, recorder);
+        activityToFragmentStateMonitorMap.put(activity, fragmentStateMonitor);
         FragmentActivity fragmentActivity = (FragmentActivity) activity;
         fragmentActivity
             .getSupportFragmentManager()
-            .registerFragmentLifecycleCallbacks(
-                new FragmentStateMonitor(clock, transportManager, this, frameMetricsAggregator),
-                true);
+            .registerFragmentLifecycleCallbacks(fragmentStateMonitor, true);
       }
     }
   }
 
   @Override
-  public void onActivityDestroyed(Activity activity) {}
+  public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
+    startFrameMonitoring(activity);
+  }
 
   @Override
-  public synchronized void onActivityStarted(Activity activity) {}
+  public void onActivityDestroyed(Activity activity) {
+    // Dereference FrameMetricsRecorder from the map because it holds an Activity reference
+    activityToRecorderMap.remove(activity);
+    // Dereference FragmentStateMonitor because it holds a FrameMetricsRecorder reference
+    if (activityToFragmentStateMonitorMap.containsKey(activity)) {
+      FragmentActivity fragmentActivity = (FragmentActivity) activity;
+      fragmentActivity
+          .getSupportFragmentManager()
+          .unregisterFragmentLifecycleCallbacks(activityToFragmentStateMonitorMap.remove(activity));
+    }
+  }
+
+  @Override
+  public synchronized void onActivityStarted(Activity activity) {
+    if (isScreenTraceSupported() && configResolver.isPerformanceMonitoringEnabled()) {
+      if (!activityToRecorderMap.containsKey(activity)) {
+        // If performance monitoring is disabled at start and enabled at runtime, start monitoring
+        // the activity as the app comes to foreground.
+        startFrameMonitoring(activity);
+      }
+      // Starts recording frame metrics for this activity.
+      activityToRecorderMap.get(activity).start();
+      // Start the Trace
+      Trace screenTrace = new Trace(getScreenTraceName(activity), transportManager, clock, this);
+      screenTrace.start();
+      activityToScreenTraceMap.put(activity, screenTrace);
+    }
+  }
 
   @Override
   public synchronized void onActivityStopped(Activity activity) {
+    if (isScreenTraceSupported()) {
+      sendScreenTrace(activity);
+    }
+
     // Last activity has its onActivityStopped called, the app goes to background.
     if (activityToResumedMap.containsKey(activity)) {
       activityToResumedMap.remove(activity);
@@ -211,20 +250,6 @@ public synchronized void onActivityResumed(Activity activity) {
       // current activity was paused then resumed without onStop, for example by an AlertDialog
       activityToResumedMap.put(activity, true);
     }
-
-    // Screen trace is after session update so the sessionId is not added twice to the Trace
-    if (isScreenTraceSupported() && configResolver.isPerformanceMonitoringEnabled()) {
-      // Starts recording frame metrics for this activity.
-      /**
-       * TODO: Only add activities that are hardware acceleration enabled so that calling {@link
-       * FrameMetricsAggregator#remove(Activity)} will not throw exceptions.
-       */
-      frameMetricsAggregator.add(activity);
-      // Start the Trace
-      Trace screenTrace = new Trace(getScreenTraceName(activity), transportManager, clock, this);
-      screenTrace.start();
-      activityToScreenTraceMap.put(activity, screenTrace);
-    }
   }
 
   /** Returns if this is the cold start of the app. */
@@ -315,54 +340,24 @@ public void onActivitySaveInstanceState(Activity activity, Bundle outState) {}
   @Override
   public void onActivityPaused(Activity activity) {}
 
-  /** Stops screen trace right after onPause because of b/210055697 */
-  @Override
-  public void onActivityPostPaused(@NonNull Activity activity) {
-    if (isScreenTraceSupported()) {
-      sendScreenTrace(activity);
-    }
-  }
-
   /**
-   * Send screen trace. If hardware acceleration is not enabled, all frame metrics will be zero and
-   * the trace will not be sent.
+   * Sends the screen trace for the provided activity.
    *
    * @param activity activity object.
    */
   private void sendScreenTrace(Activity activity) {
-    if (!activityToScreenTraceMap.containsKey(activity)) {
-      return;
-    }
     Trace screenTrace = activityToScreenTraceMap.get(activity);
     if (screenTrace == null) {
       return;
     }
     activityToScreenTraceMap.remove(activity);
 
-    int totalFrames = 0;
-    int slowFrames = 0;
-    int frozenFrames = 0;
-    /**
-     * Resets the metrics data and returns the currently-collected metrics. Note that {@link
-     * FrameMetricsAggregator#reset()} will not stop recording for the activity. The reason of using
-     * {@link FrameMetricsAggregator#reset()} is that {@link
-     * FrameMetricsAggregator#remove(Activity)} will throw exceptions for hardware acceleration
-     * disabled activities.
-     */
-    try {
-      frameMetricsAggregator.remove(activity);
-    } catch (IllegalArgumentException ignored) {
-      logger.debug("View not hardware accelerated. Unable to collect screen trace.");
-    }
-    FrameMetricsCalculator.PerfFrameMetrics perfFrameMetrics =
-        FrameMetricsCalculator.calculateFrameMetrics(frameMetricsAggregator.reset());
-    if (perfFrameMetrics.getTotalFrames() == 0
-        && perfFrameMetrics.getSlowFrames() == 0
-        && perfFrameMetrics.getFrozenFrames() == 0) {
-      // All metrics are zero, no need to send screen trace.
+    Optional<PerfFrameMetrics> perfFrameMetrics = activityToRecorderMap.get(activity).stop();
+    if (!perfFrameMetrics.isAvailable()) {
+      logger.warn("Failed to record frame data for %s.", activity.getClass().getSimpleName());
       return;
     }
-    ScreenTraceUtil.addFrameCounters(screenTrace, perfFrameMetrics);
+    ScreenTraceUtil.addFrameCounters(screenTrace, perfFrameMetrics.get());
     // Stop and record trace
     screenTrace.stop();
   }
@@ -407,23 +402,16 @@ private void sendSessionLog(String name, Timer startTime, Timer endTime) {
    * @return true if supported, false if not.
    */
   protected boolean isScreenTraceSupported() {
-    return hasFrameMetricsAggregator;
+    return screenPerformanceRecordingSupported;
   }
 
   /**
    * FrameMetricsAggregator first appears in Android Support Library 26.1.0. Before GMSCore SDK is
    * updated to 26.1.0 (b/69954793), there will be ClassNotFoundException. This method is to check
    * if FrameMetricsAggregator exists to avoid ClassNotFoundException.
    */
-  private static boolean hasFrameMetricsAggregatorClass() {
-    try {
-      Class<?> initializerClass = Class.forName(FRAME_METRICS_AGGREGATOR_CLASSNAME);
-      hasFrameMetricsAggregator = true;
-      return true;
-    } catch (ClassNotFoundException e) {
-      hasFrameMetricsAggregator = false;
-      return false;
-    }
+  private static boolean isScreenPerformanceRecordingSupported() {
+    return FrameMetricsRecorder.isFrameMetricsRecordingSupported();
   }
 
   /** An interface to be implemented by subscribers which needs to receive app state update. */

firebase-perf/src/main/java/com/google/firebase/perf/application/FragmentStateMonitor.java

@@ -15,38 +15,36 @@
 package com.google.firebase.perf.application;
 
 import androidx.annotation.NonNull;
-import androidx.core.app.FrameMetricsAggregator;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import com.google.android.gms.common.util.VisibleForTesting;
 import com.google.firebase.perf.logging.AndroidLogger;
-import com.google.firebase.perf.metrics.FrameMetricsCalculator;
 import com.google.firebase.perf.metrics.FrameMetricsCalculator.PerfFrameMetrics;
 import com.google.firebase.perf.metrics.Trace;
 import com.google.firebase.perf.transport.TransportManager;
 import com.google.firebase.perf.util.Clock;
 import com.google.firebase.perf.util.Constants;
+import com.google.firebase.perf.util.Optional;
 import com.google.firebase.perf.util.ScreenTraceUtil;
 import java.util.WeakHashMap;
 
 public class FragmentStateMonitor extends FragmentManager.FragmentLifecycleCallbacks {
   private static final AndroidLogger logger = AndroidLogger.getInstance();
   private final WeakHashMap<Fragment, Trace> fragmentToTraceMap = new WeakHashMap<>();
-  private final WeakHashMap<Fragment, PerfFrameMetrics> fragmentToMetricsMap = new WeakHashMap<>();
   private final Clock clock;
   private final TransportManager transportManager;
   private final AppStateMonitor appStateMonitor;
-  private final FrameMetricsAggregator frameMetricsAggregator;
+  private final FrameMetricsRecorder activityFramesRecorder;
 
   public FragmentStateMonitor(
       Clock clock,
       TransportManager transportManager,
       AppStateMonitor appStateMonitor,
-      FrameMetricsAggregator fma) {
+      FrameMetricsRecorder recorder) {
     this.clock = clock;
     this.transportManager = transportManager;
     this.appStateMonitor = appStateMonitor;
-    this.frameMetricsAggregator = fma;
+    this.activityFramesRecorder = recorder;
   }
 
   /**
@@ -78,10 +76,7 @@ public void onFragmentResumed(@NonNull FragmentManager fm, @NonNull Fragment f)
           Constants.ACTIVITY_ATTRIBUTE_KEY, f.getActivity().getClass().getSimpleName());
     }
     fragmentToTraceMap.put(f, fragmentTrace);
-
-    PerfFrameMetrics perfFrameMetrics =
-        FrameMetricsCalculator.calculateFrameMetrics(this.frameMetricsAggregator.getMetrics());
-    fragmentToMetricsMap.put(f, perfFrameMetrics);
+    activityFramesRecorder.startFragment(f);
   }
 
   @Override
@@ -96,33 +91,18 @@ public void onFragmentPaused(@NonNull FragmentManager fm, @NonNull Fragment f) {
 
     Trace fragmentTrace = fragmentToTraceMap.get(f);
     fragmentToTraceMap.remove(f);
-    PerfFrameMetrics prePerfFrameMetrics = fragmentToMetricsMap.get(f);
-    fragmentToMetricsMap.remove(f);
-
-    PerfFrameMetrics curPerfFrameMetrics =
-        FrameMetricsCalculator.calculateFrameMetrics(this.frameMetricsAggregator.getMetrics());
-
-    int totalFrames = curPerfFrameMetrics.getTotalFrames() - prePerfFrameMetrics.getTotalFrames();
-    int slowFrames = curPerfFrameMetrics.getSlowFrames() - prePerfFrameMetrics.getSlowFrames();
-    int frozenFrames =
-        curPerfFrameMetrics.getFrozenFrames() - prePerfFrameMetrics.getFrozenFrames();
 
-    if (totalFrames == 0 && slowFrames == 0 && frozenFrames == 0) {
-      // All metrics are zero, no need to send screen trace.
+    Optional<PerfFrameMetrics> frameMetricsData = activityFramesRecorder.stopFragment(f);
+    if (!frameMetricsData.isAvailable()) {
+      logger.warn("onFragmentPaused: recorder failed to trace %s", f.getClass().getSimpleName());
       return;
     }
-    ScreenTraceUtil.addFrameCounters(
-        fragmentTrace, new PerfFrameMetrics(totalFrames, slowFrames, frozenFrames));
+    ScreenTraceUtil.addFrameCounters(fragmentTrace, frameMetricsData.get());
     fragmentTrace.stop();
   }
 
   @VisibleForTesting
   WeakHashMap<Fragment, Trace> getFragmentToTraceMap() {
     return fragmentToTraceMap;
   }
-
-  @VisibleForTesting
-  WeakHashMap<Fragment, PerfFrameMetrics> getFragmentToMetricsMap() {
-    return fragmentToMetricsMap;
-  }
 }

firebase-perf/src/main/java/com/google/firebase/perf/application/FrameMetricsRecorder.java

@@ -41,13 +41,24 @@
  */
 public class FrameMetricsRecorder {
   private static final AndroidLogger logger = AndroidLogger.getInstance();
+  private static final String FRAME_METRICS_AGGREGATOR_CLASSNAME =
+      "androidx.core.app.FrameMetricsAggregator";
 
   private final Activity activity;
   private final FrameMetricsAggregator frameMetricsAggregator;
   private final Map<Fragment, PerfFrameMetrics> fragmentSnapshotMap;
 
   private boolean isRecording = false;
 
+  static boolean isFrameMetricsRecordingSupported() {
+    try {
+      Class<?> initializerClass = Class.forName(FRAME_METRICS_AGGREGATOR_CLASSNAME);
+      return true;
+    } catch (ClassNotFoundException e) {
+      return false;
+    }
+  }
+
   /**
    * Creates a recorder for a specific activity.
    *