[QA] Avoid collecting normal frames (#3782)

* avoid keeping normal frames in memory when collecting slow/frozen frames
* renamed SpanFrameMetricsCollector.getTotalFrameCount method to getSlowFrozenFrameCount
* confirm no delay in UI test when there are no slow/frozen frames collected

Author: stefanosiano

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ### Fixes
 
+- Avoid collecting normal frames ([#3782](https://github.com/getsentry/sentry-java/pull/3782))
 - Ensure android initialization process continues even if options configuration block throws an exception ([#3887](https://github.com/getsentry/sentry-java/pull/3887))
 - Do not report parsing ANR error when there are no threads ([#3888](https://github.com/getsentry/sentry-java/pull/3888))
   - This should significantly reduce the number of events with message "Sentry Android SDK failed to parse system thread dump..." reported

sentry-android-core/src/main/java/io/sentry/android/core/SentryFrameMetrics.java

@@ -6,7 +6,6 @@
 @ApiStatus.Internal
 final class SentryFrameMetrics {
 
-  private int normalFrameCount;
   private int slowFrameCount;
   private int frozenFrameCount;
 
@@ -18,15 +17,11 @@ final class SentryFrameMetrics {
   public SentryFrameMetrics() {}
 
   public SentryFrameMetrics(
-      final int normalFrameCount,
       final int slowFrameCount,
       final long slowFrameDelayNanos,
       final int frozenFrameCount,
       final long frozenFrameDelayNanos,
       final long totalDurationNanos) {
-
-    this.normalFrameCount = normalFrameCount;
-
     this.slowFrameCount = slowFrameCount;
     this.slowFrameDelayNanos = slowFrameDelayNanos;
 
@@ -47,15 +42,9 @@ public void addFrame(
     } else if (isSlow) {
       slowFrameDelayNanos += delayNanos;
       slowFrameCount += 1;
-    } else {
-      normalFrameCount += 1;
     }
   }
 
-  public int getNormalFrameCount() {
-    return normalFrameCount;
-  }
-
   public int getSlowFrameCount() {
     return slowFrameCount;
   }
@@ -72,17 +61,16 @@ public long getFrozenFrameDelayNanos() {
     return frozenFrameDelayNanos;
   }
 
-  public int getTotalFrameCount() {
-    return normalFrameCount + slowFrameCount + frozenFrameCount;
+  /** Returns the sum of the slow and frozen frames. */
+  public int getSlowFrozenFrameCount() {
+    return slowFrameCount + frozenFrameCount;
   }
 
   public long getTotalDurationNanos() {
     return totalDurationNanos;
   }
 
   public void clear() {
-    normalFrameCount = 0;
-
     slowFrameCount = 0;
     slowFrameDelayNanos = 0;
 
@@ -95,7 +83,6 @@ public void clear() {
   @NotNull
   public SentryFrameMetrics duplicate() {
     return new SentryFrameMetrics(
-        normalFrameCount,
         slowFrameCount,
         slowFrameDelayNanos,
         frozenFrameCount,
@@ -110,7 +97,6 @@ public SentryFrameMetrics duplicate() {
   @NotNull
   public SentryFrameMetrics diffTo(final @NotNull SentryFrameMetrics other) {
     return new SentryFrameMetrics(
-        normalFrameCount - other.normalFrameCount,
         slowFrameCount - other.slowFrameCount,
         slowFrameDelayNanos - other.slowFrameDelayNanos,
         frozenFrameCount - other.frozenFrameCount,
@@ -123,8 +109,7 @@ public SentryFrameMetrics diffTo(final @NotNull SentryFrameMetrics other) {
    *     to 0
    */
   public boolean containsValidData() {
-    return normalFrameCount >= 0
-        && slowFrameCount >= 0
+    return slowFrameCount >= 0
         && slowFrameDelayNanos >= 0
         && frozenFrameCount >= 0
         && frozenFrameDelayNanos >= 0

sentry-android-core/src/main/java/io/sentry/android/core/SpanFrameMetricsCollector.java

@@ -192,7 +192,7 @@ private void captureFrameMetrics(@NotNull final ISpan span) {
         }
       }
 
-      int totalFrameCount = frameMetrics.getTotalFrameCount();
+      int totalFrameCount = frameMetrics.getSlowFrozenFrameCount();
 
       final long nextScheduledFrameNanos = frameMetricsCollector.getLastKnownFrameStartTimeNanos();
       // nextScheduledFrameNanos might be -1 if no frames have been scheduled for drawing yet
@@ -254,15 +254,17 @@ public void onFrameMetricCollected(
         (long) ((double) ONE_SECOND_NANOS / (double) refreshRate);
     lastKnownFrameDurationNanos = expectedFrameDurationNanos;
 
-    frames.add(
-        new Frame(
-            frameStartNanos,
-            frameEndNanos,
-            durationNanos,
-            delayNanos,
-            isSlow,
-            isFrozen,
-            expectedFrameDurationNanos));
+    if (isSlow || isFrozen) {
+      frames.add(
+          new Frame(
+              frameStartNanos,
+              frameEndNanos,
+              durationNanos,
+              delayNanos,
+              isSlow,
+              isFrozen,
+              expectedFrameDurationNanos));
+    }
   }
 
   private static int interpolateFrameCount(
@@ -277,7 +279,7 @@ private static int interpolateFrameCount(
     final long frameMetricsDurationNanos = frameMetrics.getTotalDurationNanos();
     final long nonRenderedDuration = spanDurationNanos - frameMetricsDurationNanos;
     if (nonRenderedDuration > 0) {
-      return (int) (nonRenderedDuration / frameDurationNanos);
+      return (int) Math.ceil((double) nonRenderedDuration / frameDurationNanos);
     }
     return 0;
   }

sentry-android-core/src/test/java/io/sentry/android/core/SentryFrameMetricsTest.kt

@@ -6,15 +6,6 @@ import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
 class SentryFrameMetricsTest {
-    @Test
-    fun addFastFrame() {
-        val frameMetrics = SentryFrameMetrics()
-        frameMetrics.addFrame(10, 0, false, false)
-        assertEquals(1, frameMetrics.normalFrameCount)
-
-        frameMetrics.addFrame(10, 0, false, false)
-        assertEquals(2, frameMetrics.normalFrameCount)
-    }
 
     @Test
     fun addSlowFrame() {
@@ -43,10 +34,12 @@ class SentryFrameMetricsTest {
     @Test
     fun totalFrameCount() {
         val frameMetrics = SentryFrameMetrics()
+        // Normal frames are ignored
         frameMetrics.addFrame(10, 0, false, false)
+        // Slow and frozen frames are considered
         frameMetrics.addFrame(116, 100, true, false)
         frameMetrics.addFrame(1016, 1000, true, true)
-        assertEquals(3, frameMetrics.totalFrameCount)
+        assertEquals(2, frameMetrics.slowFrozenFrameCount)
     }
 
     @Test
@@ -57,12 +50,11 @@ class SentryFrameMetricsTest {
         frameMetrics.addFrame(1016, 1000, true, true)
 
         val dup = frameMetrics.duplicate()
-        assertEquals(1, dup.normalFrameCount)
         assertEquals(1, dup.slowFrameCount)
         assertEquals(100, dup.slowFrameDelayNanos)
         assertEquals(1, dup.frozenFrameCount)
         assertEquals(1000, dup.frozenFrameDelayNanos)
-        assertEquals(3, dup.totalFrameCount)
+        assertEquals(2, dup.slowFrozenFrameCount)
     }
 
     @Test
@@ -89,7 +81,7 @@ class SentryFrameMetricsTest {
         assertEquals(1, diff.frozenFrameCount)
         assertEquals(1000, diff.frozenFrameDelayNanos)
 
-        assertEquals(2, diff.totalFrameCount)
+        assertEquals(2, diff.slowFrozenFrameCount)
     }
 
     @Test
@@ -102,12 +94,11 @@ class SentryFrameMetricsTest {
 
         frameMetrics.clear()
 
-        assertEquals(0, frameMetrics.normalFrameCount)
         assertEquals(0, frameMetrics.slowFrameCount)
         assertEquals(0, frameMetrics.slowFrameDelayNanos)
         assertEquals(0, frameMetrics.frozenFrameCount)
         assertEquals(0, frameMetrics.frozenFrameDelayNanos)
-        assertEquals(0, frameMetrics.totalFrameCount)
+        assertEquals(0, frameMetrics.slowFrozenFrameCount)
     }
 
     @Test

sentry-android-core/src/test/java/io/sentry/android/core/SpanFrameMetricsCollectorTest.kt

@@ -192,7 +192,7 @@ class SpanFrameMetricsCollectorTest {
         sut.onFrameMetricCollected(0, 10, 10, 0, false, false, 60.0f)
         sut.onFrameMetricCollected(16, 48, 32, 16, true, false, 60.0f)
         sut.onFrameMetricCollected(60, 92, 32, 16, true, false, 60.0f)
-        sut.onFrameMetricCollected(100, 800, 800, 784, true, true, 60.0f)
+        sut.onFrameMetricCollected(100, 800, 700, 784, true, true, 60.0f)
 
         // then a second span starts
         fixture.timeNanos = 800
@@ -337,10 +337,11 @@ class SpanFrameMetricsCollectorTest {
         fixture.timeNanos = TimeUnit.SECONDS.toNanos(2)
         sut.onSpanFinished(span)
 
-        // then still 60 frames should be reported (1 second at 60fps)
-        verify(span).setData("frames.total", 60)
+        // then still 61 frames should be reported (1 second at 60fps with approximation)
+        verify(span).setData("frames.total", 61)
         verify(span).setData("frames.slow", 0)
         verify(span).setData("frames.frozen", 0)
+        verify(span).setData("frames.delay", 0.0)
     }
 
     @Test
@@ -364,9 +365,9 @@ class SpanFrameMetricsCollectorTest {
         sut.onSpanFinished(span)
 
         // then
-        // still 60 fps should be reported for 1 seconds
+        // still 61 fps should be reported for 1 seconds (with approximation)
         // and one frame with frame delay should be reported (1s - 16ms)
-        verify(span).setData("frames.total", 61)
+        verify(span).setData("frames.total", 62)
         verify(span).setData("frames.slow", 0)
         verify(span).setData("frames.frozen", 1)
         verify(span).setData(eq("frames.delay"), AdditionalMatchers.eq(0.983333334, 0.01))