diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector.js b/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector.js
new file mode 100644
index 0000000000..28c46f4e9e
--- /dev/null
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector.js
@@ -0,0 +1,61 @@
+/**
+ * @license
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+(function() {
+ 'use strict';
+
+ const JANK_SLEEP_TIME_MS = 1000;
+
+ const GrJankDetector = {
+ // Slowdowns counter.
+ jank: 0,
+ fps: 0,
+ _lastFrameTime: 0,
+
+ start() {
+ this._requestAnimationFrame(this._detect.bind(this));
+ },
+
+ _requestAnimationFrame(callback) {
+ window.requestAnimationFrame(callback);
+ },
+
+ _detect(now) {
+ if (this._lastFrameTime === 0) {
+ this._lastFrameTime = now;
+ this.fps = 0;
+ this._requestAnimationFrame(this._detect.bind(this));
+ return;
+ }
+ const fpsNow = 1000/(now - this._lastFrameTime);
+ this._lastFrameTime = now;
+ // Calculate moving average within last 3 measurements.
+ this.fps = this.fps === 0 ? fpsNow : ((this.fps * 2 + fpsNow) / 3);
+ if (this.fps > 10) {
+ this._requestAnimationFrame(this._detect.bind(this));
+ } else {
+ this.jank++;
+ console.warn('JANK', this.jank);
+ this._lastFrameTime = 0;
+ window.setTimeout(
+ () => this._requestAnimationFrame(this._detect.bind(this)),
+ JANK_SLEEP_TIME_MS);
+ }
+ },
+ };
+
+ window.GrJankDetector = GrJankDetector;
+})();
diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector_test.html b/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector_test.html
new file mode 100644
index 0000000000..6faeec1d81
--- /dev/null
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-jank-detector_test.html
@@ -0,0 +1,78 @@
+
+
+
+
+gr-jank-detector
+
+
+
+
+
+
+
+
diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.html b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.html
index 2970a267e2..cbb2c0977b 100644
--- a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.html
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.html
@@ -19,5 +19,6 @@ limitations under the License.
+
diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.js b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.js
index 0db442f015..ae67dac024 100644
--- a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.js
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting.js
@@ -48,6 +48,14 @@
STARTED_HIDDEN: 'hidden',
};
+ // Frame rate related constants.
+ const JANK = {
+ TYPE: 'lifecycle',
+ CATEGORY: 'UI Latency',
+ // Reported events - alphabetize below.
+ COUNT: 'Jank count',
+ };
+
// Navigation reporting constants.
const NAVIGATION = {
TYPE: 'nav-report',
@@ -118,6 +126,8 @@
};
catchErrors();
+ GrJankDetector.start();
+
const GrReporting = Polymer({
is: 'gr-reporting',
@@ -206,6 +216,11 @@
},
beforeLocationChanged() {
+ if (GrJankDetector.jank > 0) {
+ this.reporter(
+ JANK.TYPE, JANK.CATEGORY, JANK.COUNT, GrJankDetector.jank);
+ GrJankDetector.jank = 0;
+ }
for (const prop of Object.keys(this._baselines)) {
delete this._baselines[prop];
}
diff --git a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
index bfb45f6943..e2bb83d900 100644
--- a/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
+++ b/polygerrit-ui/app/elements/core/gr-reporting/gr-reporting_test.html
@@ -93,7 +93,11 @@ limitations under the License.
test('beforeLocationChanged', () => {
element._baselines['garbage'] = 'monster';
sandbox.stub(element, 'time');
+ GrJankDetector.jank = 42;
element.beforeLocationChanged();
+ assert.equal(GrJankDetector.jank, 0);
+ assert.isTrue(element.reporter.calledWithExactly(
+ 'lifecycle', 'UI Latency', 'Jank count', 42));
assert.isTrue(element.time.calledWithExactly('DashboardDisplayed'));
assert.isTrue(element.time.calledWithExactly('ChangeDisplayed'));
assert.isTrue(element.time.calledWithExactly('DiffViewDisplayed'));
diff --git a/polygerrit-ui/app/test/index.html b/polygerrit-ui/app/test/index.html
index 6cf674a2ef..6a562fcb86 100644
--- a/polygerrit-ui/app/test/index.html
+++ b/polygerrit-ui/app/test/index.html
@@ -88,6 +88,7 @@ limitations under the License.
'core/gr-error-manager/gr-error-manager_test.html',
'core/gr-main-header/gr-main-header_test.html',
'core/gr-navigation/gr-navigation_test.html',
+ 'core/gr-reporting/gr-jank-detector_test.html',
'core/gr-reporting/gr-reporting_test.html',
'core/gr-router/gr-router_test.html',
'core/gr-search-bar/gr-search-bar_test.html',