Revert "fix duration event of timeline summary (#47742)" (#47888)

This reverts commit e43fd1c5.

packages/flutter_driver/lib/src/driver/timeline_summary.dart

@@ -57,27 +57,27 @@ class TimelineSummary {
   ///
   /// Returns null if no frames were recorded.
   double computeAverageFrameRasterizerTimeMillis() {
-    return _averageInMillis(_extractGpuRasterizerDrawDurations());
+    return _averageInMillis(_extractDuration(_extractGpuRasterizerDrawEvents()));
   }
 
   /// The longest frame rasterization time in milliseconds.
   ///
   /// Returns null if no frames were recorded.
   double computeWorstFrameRasterizerTimeMillis() {
-    return _maxInMillis(_extractGpuRasterizerDrawDurations());
+    return _maxInMillis(_extractDuration(_extractGpuRasterizerDrawEvents()));
   }
 
   /// The [p]-th percentile frame rasterization time in milliseconds.
   ///
   /// Returns null if no frames were recorded.
   double computePercentileFrameRasterizerTimeMillis(double p) {
-    return _percentileInMillis(_extractGpuRasterizerDrawDurations(), p);
+    return _percentileInMillis(_extractDuration(_extractGpuRasterizerDrawEvents()), p);
   }
 
   /// The number of frames that missed the [kBuildBudget] on the GPU and
   /// therefore are in the danger of missing frames.
-  int computeMissedFrameRasterizerBudgetCount([ Duration frameBuildBudget = kBuildBudget ]) => _extractGpuRasterizerDrawDurations()
-      .where((Duration duration) => duration > kBuildBudget)
+  int computeMissedFrameRasterizerBudgetCount([ Duration frameBuildBudget = kBuildBudget ]) => _extractGpuRasterizerDrawEvents()
+      .where((TimedEvent event) => event.duration > kBuildBudget)
       .length;
 
   /// The total number of frames recorded in the timeline.
@@ -100,8 +100,8 @@ class TimelineSummary {
       'frame_build_times': _extractFrameDurations()
         .map<int>((Duration duration) => duration.inMicroseconds)
         .toList(),
-      'frame_rasterizer_times': _extractGpuRasterizerDrawDurations()
-        .map<int>((Duration duration) => duration.inMicroseconds)
+      'frame_rasterizer_times': _extractGpuRasterizerDrawEvents()
+        .map<int>((TimedEvent event) => event.duration.inMicroseconds)
         .toList(),
     };
   }
@@ -142,11 +142,15 @@ class TimelineSummary {
       .toList();
   }
 
-  /// Extracts Duration list that are reported as a pair of begin/end events.
+  List<Duration> _extractDurations(String name) {
+    return _extractNamedEvents(name).map<Duration>((TimelineEvent event) => event.duration).toList();
+  }
+
+  /// Extracts timed events that are reported as a pair of begin/end events.
   ///
   /// See: https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU
-  List<Duration> _extractBeginEndEvents(String name) {
-    final List<Duration> result = <Duration>[];
+  List<TimedEvent> _extractBeginEndEvents(String name) {
+    final List<TimedEvent> result = <TimedEvent>[];
 
     // Timeline does not guarantee that the first event is the "begin" event.
     final Iterator<TimelineEvent> events = _extractNamedEvents(name)
@@ -155,7 +159,10 @@ class TimelineSummary {
       final TimelineEvent beginEvent = events.current;
       if (events.moveNext()) {
         final TimelineEvent endEvent = events.current;
-        result.add(Duration(microseconds: endEvent.timestampMicros - beginEvent.timestampMicros));
+        result.add(TimedEvent(
+          beginEvent.timestampMicros,
+          endEvent.timestampMicros,
+        ));
       }
     }
 
@@ -187,7 +194,21 @@ class TimelineSummary {
         .reduce(math.max);
   }
 
-  List<Duration> _extractGpuRasterizerDrawDurations() => _extractBeginEndEvents('GPURasterizer::Draw');
+  List<TimedEvent> _extractGpuRasterizerDrawEvents() => _extractBeginEndEvents('GPURasterizer::Draw');
+
+  List<Duration> _extractFrameDurations() => _extractDurations('Frame');
+
+  Iterable<Duration> _extractDuration(Iterable<TimedEvent> events) {
+    return events.map<Duration>((TimedEvent e) => e.duration);
+  }
+}
+
+/// Timing information about an event that happened in the event loop.
+class TimedEvent {
+  /// Creates a timed event given begin and end timestamps in microseconds.
+  TimedEvent(int beginTimeMicros, int endTimeMicros)
+    : duration = Duration(microseconds: endTimeMicros - beginTimeMicros);
 
-  List<Duration> _extractFrameDurations() => _extractBeginEndEvents('Frame');
+  /// The duration of the event.
+  final Duration duration;
 }

packages/flutter_driver/test/src/timeline_summary_test.dart

@@ -20,16 +20,11 @@ void main() {
       }));
     }
 
-    Map<String, dynamic> frameBegin(int timeStamp) => <String, dynamic>{
+    Map<String, dynamic> build(int timeStamp, int duration) => <String, dynamic>{
       'name': 'Frame',
-      'ph': 'B',
-      'ts': timeStamp,
-    };
-
-    Map<String, dynamic> frameEnd(int timeStamp) => <String, dynamic>{
-      'name': 'Frame',
-      'ph': 'E',
+      'ph': 'X',
       'ts': timeStamp,
+      'dur': duration,
     };
 
     Map<String, dynamic> begin(int timeStamp) => <String, dynamic>{
@@ -59,8 +54,8 @@ void main() {
       test('counts frames', () {
         expect(
           summarize(<Map<String, dynamic>>[
-            frameBegin(1000), frameEnd(2000),
-            frameBegin(3000), frameEnd(5000),
+            build(1000, 1000),
+            build(3000, 2000),
           ]).countFrames(),
           2,
         );
@@ -78,32 +73,12 @@ void main() {
       test('computes average frame build time in milliseconds', () {
         expect(
           summarize(<Map<String, dynamic>>[
-            frameBegin(1000), frameEnd(2000),
-            frameBegin(3000), frameEnd(5000),
+            build(1000, 1000),
+            build(3000, 2000),
           ]).computeAverageFrameBuildTimeMillis(),
           1.5,
         );
       });
-
-      test('skips leading "end" events', () {
-        expect(
-          summarize(<Map<String, dynamic>>[
-            frameEnd(1000),
-            frameBegin(2000), frameEnd(4000),
-          ]).computeAverageFrameBuildTimeMillis(),
-          2.0,
-        );
-      });
-
-      test('skips trailing "begin" events', () {
-        expect(
-          summarize(<Map<String, dynamic>>[
-            frameBegin(2000), frameEnd(4000),
-            frameBegin(5000),
-          ]).computeAverageFrameBuildTimeMillis(),
-          2.0,
-        );
-      });
     });
 
     group('worst_frame_build_time_millis', () {
@@ -117,35 +92,15 @@ void main() {
       test('computes worst frame build time in milliseconds', () {
         expect(
           summarize(<Map<String, dynamic>>[
-            frameBegin(1000), frameEnd(2000),
-            frameBegin(3000), frameEnd(5000),
-          ]).computeWorstFrameBuildTimeMillis(),
-          2.0,
-        );
-        expect(
-          summarize(<Map<String, dynamic>>[
-            frameBegin(3000), frameEnd(5000),
-            frameBegin(1000), frameEnd(2000),
+            build(1000, 1000),
+            build(3000, 2000),
           ]).computeWorstFrameBuildTimeMillis(),
           2.0,
         );
-      });
-
-      test('skips leading "end" events', () {
-        expect(
-          summarize(<Map<String, dynamic>>[
-            frameEnd(1000),
-            frameBegin(2000), frameEnd(4000),
-          ]).computeWorstFrameBuildTimeMillis(),
-          2.0,
-        );
-      });
-
-      test('skips trailing "begin" events', () {
         expect(
           summarize(<Map<String, dynamic>>[
-            frameBegin(2000), frameEnd(4000),
-            frameBegin(5000),
+            build(3000, 2000),
+            build(1000, 1000),
           ]).computeWorstFrameBuildTimeMillis(),
           2.0,
         );
@@ -155,9 +110,9 @@ void main() {
     group('computeMissedFrameBuildBudgetCount', () {
       test('computes the number of missed build budgets', () {
         final TimelineSummary summary = summarize(<Map<String, dynamic>>[
-          frameBegin(1000), frameEnd(18000),
-          frameBegin(19000), frameEnd(28000),
-          frameBegin(29000), frameEnd(47000),
+          build(1000, 17000),
+          build(19000, 9000),
+          build(29000, 18000),
         ]);
 
         expect(summary.countFrames(), 3);
@@ -312,9 +267,9 @@ void main() {
             begin(1000), end(19000),
             begin(19000), end(29000),
             begin(29000), end(49000),
-            frameBegin(1000), frameEnd(18000),
-            frameBegin(19000), frameEnd(28000),
-            frameBegin(29000), frameEnd(48000),
+            build(1000, 17000),
+            build(19000, 9000),
+            build(29000, 19000),
           ]).summaryJson,
           <String, dynamic>{
             'average_frame_build_time_millis': 15.0,
@@ -362,9 +317,9 @@ void main() {
           begin(1000), end(19000),
           begin(19000), end(29000),
           begin(29000), end(49000),
-          frameBegin(1000), frameEnd(18000),
-          frameBegin(19000), frameEnd(28000),
-          frameBegin(29000), frameEnd(48000),
+          build(1000, 17000),
+          build(19000, 9000),
+          build(29000, 19000),
         ]).writeSummaryToFile('test', destinationDirectory: tempDir.path);
         final String written =
             await fs.file(path.join(tempDir.path, 'test.timeline_summary.json')).readAsString();