Attempt to simplify AQS session usage

Author: tejasd

firebase-perf/src/main/java/com/google/firebase/perf/session/PerfSession.java

@@ -30,7 +30,8 @@
 /** Details of a session including a unique Id and related information. */
 public class PerfSession implements Parcelable {
 
-  private final String internalSessionId;
+  private static final String SESSION_ID_PREFIX = "fireperf-session";
+  private final String sessionId;
   private final Timer creationTime;
 
   private boolean isGaugeAndEventCollectionEnabled = false;
@@ -39,42 +40,39 @@ public class PerfSession implements Parcelable {
    * Creates a PerfSession object and decides what metrics to collect.
    */
   public static PerfSession createNewSession() {
-    String prunedSessionId = UUID.randomUUID().toString().replace("-", "");
+    String prunedSessionId = SESSION_ID_PREFIX + UUID.randomUUID().toString().replace("-", "");
     PerfSession session = new PerfSession(prunedSessionId, new Clock());
     session.setGaugeAndEventCollectionEnabled(shouldCollectGaugesAndEvents());
-
-    // Every time a PerfSession is created, it sets the AQS to null. Once an AQS is received,
-    // SessionManagerKt verifies if this is an active session, and sets the AQS session ID.
-    // The assumption is that new PerfSessions *should* be limited to either App Start, or through
-    // AQS.
-    FirebasePerformanceSessionSubscriber.Companion.getInstance().reportPerfSession(prunedSessionId);
-
     return session;
   }
 
   /** Creates a PerfSession with the provided {@code sessionId} and {@code clock}. */
   @VisibleForTesting(otherwise = VisibleForTesting.PACKAGE_PRIVATE)
-  public PerfSession(String internalSessionId, Clock clock) {
-    this.internalSessionId = internalSessionId;
+  public PerfSession(String sessionId, Clock clock) {
+    this.sessionId = sessionId;
     creationTime = clock.getTime();
+    // Every time a PerfSession is created, it sets the AQS to null. Once an AQS is received,
+    // SessionManagerKt verifies if this is an active session, and sets the AQS session ID.
+    // The assumption is that new PerfSessions *should* be limited to either App Start, or through
+    // AQS.
+    FirebasePerformanceSessionSubscriber.Companion.getInstance().reportPerfSession(sessionId);
   }
 
   private PerfSession(@NonNull Parcel in) {
     super();
-    internalSessionId = in.readString();
+    sessionId = in.readString();
     isGaugeAndEventCollectionEnabled = in.readByte() != 0;
     creationTime = in.readParcelable(Timer.class.getClassLoader());
   }
 
   /** Returns the sessionId of the object. */
   public String sessionId() {
-    return FirebasePerformanceSessionSubscriber.Companion.getInstance()
-        .getAqsMappedToPerfSession(this.internalSessionId);
+    return this.sessionId;
   }
 
-  @VisibleForTesting(otherwise = VisibleForTesting.PACKAGE_PRIVATE)
-  public String getInternalSessionId() {
-    return internalSessionId;
+  private String aqsSessionId() {
+    return FirebasePerformanceSessionSubscriber.Companion.getInstance()
+        .getAqsMappedToPerfSession(this.sessionId);
   }
 
   /**
@@ -127,7 +125,7 @@ public boolean isSessionRunningTooLong() {
   /** Creates and returns the proto object for PerfSession object. */
   public com.google.firebase.perf.v1.PerfSession build() {
     com.google.firebase.perf.v1.PerfSession.Builder sessionMetric =
-        com.google.firebase.perf.v1.PerfSession.newBuilder().setSessionId(sessionId());
+        com.google.firebase.perf.v1.PerfSession.newBuilder().setSessionId(aqsSessionId());
 
     // If gauge collection is enabled, enable gauge collection verbosity.
     if (isGaugeAndEventCollectionEnabled) {
@@ -202,7 +200,7 @@ public int describeContents() {
    * @param flags Additional flags about how the object should be written.
    */
   public void writeToParcel(@NonNull Parcel out, int flags) {
-    out.writeString(internalSessionId);
+    out.writeString(sessionId);
     out.writeByte((byte) (isGaugeAndEventCollectionEnabled ? 1 : 0));
     out.writeParcelable(creationTime, 0);
   }

firebase-perf/src/main/java/com/google/firebase/perf/session/SessionManager.java

@@ -40,8 +40,6 @@ public class SessionManager {
   @SuppressLint("StaticFieldLeak")
   private static final SessionManager instance = new SessionManager();
 
-  private static final String COLD_START_GAUGE_NAME = "coldstart";
-
   private final GaugeManager gaugeManager;
   private final AppStateMonitor appStateMonitor;
   private final Set<WeakReference<SessionAwareObject>> clients = new HashSet<>();
@@ -115,8 +113,7 @@ public void stopGaugeCollectionIfSessionRunningTooLong() {
    */
   public void updatePerfSession(PerfSession perfSession) {
     // Do not update the perf session if it is the exact same sessionId.
-    if (Objects.equals(
-        perfSession.getInternalSessionId(), this.perfSession.getInternalSessionId())) {
+    if (Objects.equals(perfSession.sessionId(), this.perfSession.sessionId())) {
       return;
     }
 

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/GaugeManager.java

@@ -22,6 +22,7 @@
 import com.google.firebase.components.Lazy;
 import com.google.firebase.perf.config.ConfigResolver;
 import com.google.firebase.perf.logging.AndroidLogger;
+import com.google.firebase.perf.session.FirebasePerformanceSessionSubscriber;
 import com.google.firebase.perf.session.PerfSession;
 import com.google.firebase.perf.transport.TransportManager;
 import com.google.firebase.perf.util.Timer;
@@ -72,16 +73,16 @@ private GaugeManager() {
         TransportManager.getInstance(),
         ConfigResolver.getInstance(),
         null,
-        new Lazy<>(CpuGaugeCollector::new),
-        new Lazy<>(MemoryGaugeCollector::new));
+        new Lazy<>(() -> new CpuGaugeCollector()),
+        new Lazy<>(() -> new MemoryGaugeCollector()));
   }
 
   @VisibleForTesting
   GaugeManager(
       Lazy<ScheduledExecutorService> gaugeManagerExecutor,
       TransportManager transportManager,
       ConfigResolver configResolver,
-      @Nullable GaugeMetadataManager gaugeMetadataManager,
+      GaugeMetadataManager gaugeMetadataManager,
       Lazy<CpuGaugeCollector> cpuGaugeCollector,
       Lazy<MemoryGaugeCollector> memoryGaugeCollector) {
 
@@ -136,12 +137,11 @@ public void startCollectingGauges(
     final String sessionIdForScheduledTask = sessionId;
     final ApplicationProcessState applicationProcessStateForScheduledTask = applicationProcessState;
 
-    // TODO(b/394127311): Switch to using AQS.
     try {
       gaugeManagerDataCollectionJob =
           gaugeManagerExecutor
               .get()
-              .scheduleWithFixedDelay(
+              .scheduleAtFixedRate(
                   () -> {
                     syncFlush(sessionIdForScheduledTask, applicationProcessStateForScheduledTask);
                   },
@@ -205,7 +205,6 @@ public void stopCollectingGauges() {
       gaugeManagerDataCollectionJob.cancel(false);
     }
 
-    // TODO(b/394127311): Switch to using AQS.
     // Flush any data that was collected for this session one last time.
     @SuppressWarnings("FutureReturnValueIgnored")
     ScheduledFuture unusedFuture =
@@ -244,21 +243,26 @@ private void syncFlush(String sessionId, ApplicationProcessState appState) {
     }
 
     // Adding Session ID info.
-    // TODO(b/394127311): Switch to using AQS.
-    gaugeMetricBuilder.setSessionId(sessionId);
+    String aqsSessionId =
+        FirebasePerformanceSessionSubscriber.Companion.getInstance()
+            .getAqsMappedToPerfSession(sessionId);
+    gaugeMetricBuilder.setSessionId(aqsSessionId);
 
     transportManager.log(gaugeMetricBuilder.build(), appState);
   }
 
   /**
    * Log the Gauge Metadata information to the transport.
    *
-   * @param aqsSessionId The {@link PerfSession#aqsSessionId()} ()} to which the collected Gauge Metrics
+   * @param sessionId The {@link PerfSession#sessionId()} to which the collected Gauge Metrics
    *     should be associated with.
    * @param appState The {@link ApplicationProcessState} for which these gauges are collected.
    * @return true if GaugeMetadata was logged, false otherwise.
    */
-  public boolean logGaugeMetadata(String aqsSessionId, ApplicationProcessState appState) {
+  public boolean logGaugeMetadata(String sessionId, ApplicationProcessState appState) {
+    String aqsSessionId =
+        FirebasePerformanceSessionSubscriber.Companion.getInstance()
+            .getAqsMappedToPerfSession(sessionId);
     if (gaugeMetadataManager != null) {
       GaugeMetric gaugeMetric =
           GaugeMetric.newBuilder()