Add instrumentation for performance metrics tracking

build/rollup_plugins.js

@@ -7,8 +7,8 @@ import unassert from 'rollup-plugin-unassert';
 import json from 'rollup-plugin-json';
 import {terser} from 'rollup-plugin-terser';
 import minifyStyleSpec from './rollup_plugin_minify_style_spec';
-import strip from '@rollup/plugin-strip';
 import {createFilter} from 'rollup-pluginutils';
+import strip from '@rollup/plugin-strip';
 
 // Common set of plugins/transformations shared across different rollup
 // builds (main mapboxgl bundle, style-spec package, benchmarks bundle)
@@ -18,7 +18,8 @@ export const plugins = (minified, production) => [
     minifyStyleSpec(),
     json(),
     production ? strip({
-        functions: ['Debug.*']
+        sourceMap: true,
+        functions: ['PerformanceUtils.*', 'Debug.*']
     }) : false,
     glsl('./src/shaders/*.glsl', production),
     buble({transforms: {dangerousForOf: true}, objectAssign: "Object.assign"}),

src/index.js

@@ -24,6 +24,7 @@ import {isSafari} from './util/util';
 import {setRTLTextPlugin, getRTLTextPluginStatus} from './source/rtl_text_plugin';
 import WorkerPool from './util/worker_pool';
 import {clearTileCache} from './util/tile_request_cache';
+import {PerformanceUtils} from './util/performance';
 
 const exported = {
     version,
@@ -133,7 +134,7 @@ const exported = {
 };
 
 //This gets automatically stripped out in production builds.
-Debug.extend(exported, {isSafari});
+Debug.extend(exported, {isSafari, getPerformanceMetrics: PerformanceUtils.getPerformanceMetrics});
 
 /**
  * The version of Mapbox GL JS in use as specified in `package.json`,

src/source/geojson_worker_source.js

@@ -2,7 +2,7 @@
 
 import {getJSON} from '../util/ajax';
 
-import performance from '../util/performance';
+import {RequestPerformance} from '../util/performance';
 import rewind from '@mapbox/geojson-rewind';
 import GeoJSONWrapper from './geojson_wrapper';
 import vtpbf from 'vt-pbf';
@@ -161,7 +161,7 @@ class GeoJSONWorkerSource extends VectorTileWorkerSource {
         delete this._pendingLoadDataParams;
 
         const perf = (params && params.request && params.request.collectResourceTiming) ?
-            new performance.Performance(params.request) : false;
+            new RequestPerformance(params.request) : false;
 
         this.loadGeoJSON(params, (err: ?Error, data: ?Object) => {
             if (err || !data) {

src/source/vector_tile_worker_source.js

@@ -6,7 +6,7 @@ import vt from '@mapbox/vector-tile';
 import Protobuf from 'pbf';
 import WorkerTile from './worker_tile';
 import {extend} from '../util/util';
-import performance from '../util/performance';
+import {RequestPerformance} from '../util/performance';
 
 import type {
     WorkerSource,
@@ -104,7 +104,7 @@ class VectorTileWorkerSource implements WorkerSource {
             this.loading = {};
 
         const perf = (params && params.request && params.request.collectResourceTiming) ?
-            new performance.Performance(params.request) : false;
+            new RequestPerformance(params.request) : false;
 
         const workerTile = this.loading[uid] = new WorkerTile(params);
         workerTile.abort = this.loadVectorData(params, (err, response) => {

src/ui/map.js

@@ -26,6 +26,8 @@ import {Event, ErrorEvent} from '../util/evented';
 import {MapMouseEvent} from './events';
 import TaskQueue from '../util/task_queue';
 import webpSupported from '../util/webp_supported';
+import {PerformanceMarkers, PerformanceUtils} from '../util/performance';
+
 import {setCacheLimits} from '../util/tile_request_cache';
 
 import type {PointLike} from '@mapbox/point-geometry';
@@ -279,6 +281,8 @@ class Map extends Camera {
     _sourcesDirty: ?boolean;
     _placementDirty: ?boolean;
     _loaded: boolean;
+    // accounts for placement finishing as well
+    _fullyLoaded: boolean;
     _trackResize: boolean;
     _preserveDrawingBuffer: boolean;
     _failIfMajorPerformanceCaveat: boolean;
@@ -341,6 +345,8 @@ class Map extends Camera {
     touchZoomRotate: TouchZoomRotateHandler;
 
     constructor(options: MapOptions) {
+        PerformanceUtils.mark(PerformanceMarkers.create);
+
         options = extend({}, defaultOptions, options);
 
         if (options.minZoom != null && options.maxZoom != null && options.minZoom > options.maxZoom) {
@@ -2138,6 +2144,7 @@ class Map extends Camera {
 
         if (this.loaded() && !this._loaded) {
             this._loaded = true;
+            PerformanceUtils.mark(PerformanceMarkers.load);
             this.fire(new Event('load'));
         }
 
@@ -2184,9 +2191,14 @@ class Map extends Camera {
         // Even though `_styleDirty` and `_sourcesDirty` are reset in this
         // method, synchronous events fired during Style#update or
         // Style#_updateSources could have caused them to be set again.
-        if (this._sourcesDirty || this._repaint || this._styleDirty || this._placementDirty) {
+        const somethingDirty = this._sourcesDirty || this._styleDirty || this._placementDirty;
+        if (somethingDirty || this._repaint) {
             this.triggerRepaint();
         } else if (!this.isMoving() && this.loaded()) {
+            if (!this._fullyLoaded) {
+                this._fullyLoaded = true;
+                PerformanceUtils.mark(PerformanceMarkers.fullLoad);
+            }
             this.fire(new Event('idle'));
         }
 
@@ -2225,6 +2237,8 @@ class Map extends Camera {
         removeNode(this._controlContainer);
         removeNode(this._missingCSSCanary);
         this._container.classList.remove('mapboxgl-map');
+
+        PerformanceUtils.clearMetrics();
         this.fire(new Event('remove'));
     }
 
@@ -2235,7 +2249,8 @@ class Map extends Camera {
      */
     triggerRepaint() {
         if (this.style && !this._frame) {
-            this._frame = browser.frame(() => {
+            this._frame = browser.frame((paintStartTimestamp: number) => {
+                PerformanceUtils.frame(paintStartTimestamp);
                 this._frame = null;
                 this._render();
             });

src/util/browser.js

@@ -31,7 +31,7 @@ const exported = {
      */
     now,
 
-    frame(fn: () => void): Cancelable {
+    frame(fn: (paintStartTimestamp: number) => void): Cancelable {
         const frame = raf(fn);
         return {cancel: () => cancel(frame)};
     },

src/util/image.js

@@ -76,7 +76,6 @@ function copyImage(srcImg: *, dstImg: *, srcPt: Point, dstPt: Point, size: Size,
             dstData[dstOffset + i] = srcData[srcOffset + i];
         }
     }
-
     return dstImg;
 }
 

src/util/performance.js

@@ -1,45 +1,74 @@
 // @flow
 
+import window from '../util/window';
 import type {RequestParameters} from '../util/ajax';
 
-// Wraps performance to facilitate testing
-// Not incorporated into browser.js because the latter is poisonous when used outside the main thread
-const performanceExists = typeof performance !== 'undefined';
-const wrapper = {};
+const performance = window.performance;
 
-wrapper.getEntriesByName = (url: string) => {
-    if (performanceExists && performance && performance.getEntriesByName)
-        return performance.getEntriesByName(url);
-    else
-        return false;
-};
-
-wrapper.mark = (name: string) => {
-    if (performanceExists && performance && performance.mark)
-        return performance.mark(name);
-    else
-        return false;
-};
-
-wrapper.measure = (name: string, startMark: string, endMark: string) => {
-    if (performanceExists && performance && performance.measure)
-        return performance.measure(name, startMark, endMark);
-    else
-        return false;
-};
+export type PerformanceMetrics = {
+    loadTime: number,
+    fullLoadTime: number,
+    fps: number,
+    percentDroppedFrames: number
+}
 
-wrapper.clearMarks = (name: string) => {
-    if (performanceExists && performance && performance.clearMarks)
-        return performance.clearMarks(name);
-    else
-        return false;
+export const PerformanceMarkers = {
+    create: 'create',
+    load: 'load',
+    fullLoad: 'fullLoad'
 };
 
-wrapper.clearMeasures = (name: string) => {
-    if (performanceExists && performance && performance.clearMeasures)
-        return performance.clearMeasures(name);
-    else
-        return false;
+let lastFrameTime = null;
+let frameTimes = [];
+
+const minFramerateTarget = 30;
+const frameTimeTarget = 1000 / minFramerateTarget;
+
+export const PerformanceUtils = {
+    mark(marker: $Keys<typeof PerformanceMarkers>) {
+        performance.mark(marker);
+    },
+    frame(timestamp: number) {
+        const currTimestamp = timestamp;
+        if (lastFrameTime != null) {
+            const frameTime = currTimestamp - lastFrameTime;
+            frameTimes.push(frameTime);
+        }
+        lastFrameTime = currTimestamp;
+    },
+    clearMetrics() {
+        lastFrameTime = null;
+        frameTimes = [];
+        performance.clearMeasures('loadTime');
+        performance.clearMeasures('fullLoadTime');
+
+        for (const marker in PerformanceMarkers) {
+            performance.clearMarks(PerformanceMarkers[marker]);
+        }
+    },
+    getPerformanceMetrics(): PerformanceMetrics {
+        const loadTime = performance.measure('loadTime', PerformanceMarkers.create, PerformanceMarkers.load).duration;
+        const fullLoadTime = performance.measure('fullLoadTime', PerformanceMarkers.create, PerformanceMarkers.fullLoad).duration;
+        const totalFrames = frameTimes.length;
+
+        const avgFrameTime = frameTimes.reduce((prev, curr) => prev + curr, 0) / totalFrames / 1000;
+        const fps = 1 / avgFrameTime;
+
+        // count frames that missed our framerate target
+        const droppedFrames = frameTimes
+            .filter((frameTime) => frameTime > frameTimeTarget)
+            .reduce((acc, curr) => {
+                return acc + (curr -  frameTimeTarget) / frameTimeTarget;
+            }, 0);
+        const percentDroppedFrames = (droppedFrames / (totalFrames + droppedFrames)) * 100;
+
+        return {
+            loadTime,
+            fullLoadTime,
+            fps,
+            percentDroppedFrames
+        };
+    }
 };
 
 /**
@@ -48,7 +77,7 @@ wrapper.clearMeasures = (name: string) => {
  * @param {RequestParameters} request
  * @private
  */
-class Performance {
+export class RequestPerformance {
     _marks: {start: string, end: string, measure: string};
 
     constructor (request: RequestParameters) {
@@ -58,28 +87,26 @@ class Performance {
             measure: request.url.toString()
         };
 
-        wrapper.mark(this._marks.start);
+        performance.mark(this._marks.start);
     }
 
     finish() {
-        wrapper.mark(this._marks.end);
-        let resourceTimingData = wrapper.getEntriesByName(this._marks.measure);
+        performance.mark(this._marks.end);
+        let resourceTimingData = performance.getEntriesByName(this._marks.measure);
 
         // fallback if web worker implementation of perf.getEntriesByName returns empty
         if (resourceTimingData.length === 0) {
-            wrapper.measure(this._marks.measure, this._marks.start, this._marks.end);
-            resourceTimingData = wrapper.getEntriesByName(this._marks.measure);
+            performance.measure(this._marks.measure, this._marks.start, this._marks.end);
+            resourceTimingData = performance.getEntriesByName(this._marks.measure);
 
             // cleanup
-            wrapper.clearMarks(this._marks.start);
-            wrapper.clearMarks(this._marks.end);
-            wrapper.clearMeasures(this._marks.measure);
+            performance.clearMarks(this._marks.start);
+            performance.clearMarks(this._marks.end);
+            performance.clearMeasures(this._marks.measure);
         }
 
         return resourceTimingData;
     }
 }
 
-wrapper.Performance = Performance;
-
-export default wrapper;
+export default performance;

src/util/window.js

@@ -87,6 +87,12 @@ function restore(): Window {
 
     window.restore = restore;
 
+    window.performance.getEntriesByName = function() {};
+    window.performance.mark = function() {};
+    window.performance.measure = function() {};
+    window.performance.clearMarks = function() {};
+    window.performance.clearMeasures = function() {};
+
     window.ImageData = window.ImageData || function() { return false; };
     window.ImageBitmap = window.ImageBitmap || function() { return false; };
     window.WebGLFramebuffer = window.WebGLFramebuffer || Object;