core(lantern): add configuration for precomputed network analysis

lighthouse-cli/bin.js

@@ -105,6 +105,17 @@ if (cliFlags.extraHeaders) {
   cliFlags.extraHeaders = JSON.parse(extraHeadersStr);
 }
 
+if (cliFlags.precomputedLanternDataPath) {
+  const lanternDataStr = fs.readFileSync(cliFlags.precomputedLanternDataPath, 'utf8');
+  /** @type {LH.PrecomputedLanternData} */
+  const data = JSON.parse(lanternDataStr);
+  if (!data.additionalRttByOrigin || !data.serverResponseTimeByOrigin) {
+    throw new Error('Invalid precomputed lantern data file');
+  }
+
+  cliFlags.precomputedLanternData = data;
+}
+
 /**
  * @return {Promise<LH.RunnerResult|void>}
  */

lighthouse-cli/cli-flags.js

@@ -97,6 +97,8 @@ function getFlags(manualArgv) {
         'max-wait-for-load':
             'The timeout (in milliseconds) to wait before the page is considered done loading and the run should continue. WARNING: Very high values can lead to large traces and instability',
         'extra-headers': 'Set extra HTTP Headers to pass with request',
+        'precomputed-lantern-data-path': 'Path to the file where lantern simulation data should be read from.',
+        'lantern-data-output-path': 'Path to the file where lantern simulation data should be written to.',
         'only-audits': 'Only run the specified audits',
         'only-categories': 'Only run the specified categories',
         'skip-audits': 'Run everything except these audits',
@@ -133,6 +135,8 @@ function getFlags(manualArgv) {
       .array('skipAudits')
       .array('output')
       .string('extraHeaders')
+      .string('precomputedLanternDataPath')
+      .string('lanternDataOutputPath')
 
       // default values
       .default('chrome-flags', '')

lighthouse-cli/run.js

@@ -9,14 +9,14 @@
 
 const path = require('path');
 
-const Printer = require('./printer');
+const Printer = require('./printer.js');
 const ChromeLauncher = require('chrome-launcher');
 
 const yargsParser = require('yargs-parser');
-const lighthouse = require('../lighthouse-core');
+const lighthouse = require('../lighthouse-core/index.js');
 const log = require('lighthouse-logger');
-const getFilenamePrefix = require('../lighthouse-core/lib/file-namer').getFilenamePrefix;
-const assetSaver = require('../lighthouse-core/lib/asset-saver');
+const getFilenamePrefix = require('../lighthouse-core/lib/file-namer.js').getFilenamePrefix;
+const assetSaver = require('../lighthouse-core/lib/asset-saver.js');
 
 const opn = require('opn');
 
@@ -120,6 +120,11 @@ function handleError(err) {
 async function saveResults(runnerResult, flags) {
   const cwd = process.cwd();
 
+  if (flags.lanternDataOutputPath) {
+    const devtoolsLog = runnerResult.artifacts.devtoolsLogs.defaultPass;
+    await assetSaver.saveLanternNetworkData(devtoolsLog, flags.lanternDataOutputPath);
+  }
+
   const shouldSaveResults = flags.auditMode || (flags.gatherMode === flags.auditMode);
   if (!shouldSaveResults) return;
   const {lhr, artifacts, report} = runnerResult;

lighthouse-cli/test/cli/__snapshots__/index-test.js.snap

@@ -1213,6 +1213,7 @@ Object {
     "output": Array [
       "html",
     ],
+    "precomputedLanternData": null,
     "skipAudits": null,
     "throttling": Object {
       "cpuSlowdownMultiplier": 4,
@@ -1342,6 +1343,7 @@ Object {
     "output": Array [
       "json",
     ],
+    "precomputedLanternData": null,
     "skipAudits": null,
     "throttling": Object {
       "cpuSlowdownMultiplier": 4,

lighthouse-cli/test/smokehouse/lantern-config.js

@@ -0,0 +1,24 @@
+/**
+ * @license Copyright 2017 Google Inc. All Rights Reserved.
+ * 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.
+ */
+'use strict';
+
+/**
+ * Config file for running byte efficiency smokehouse audits.
+ */
+module.exports = {
+  extends: 'lighthouse:full',
+  settings: {
+    onlyCategories: ['performance'],
+    precomputedLanternData: {
+      additionalRttByOrigin: {
+        'http://localhost:10200': 500,
+      },
+      serverResponseTimeByOrigin: {
+        'http://localhost:10200': 1000,
+      },
+    },
+  },
+};

lighthouse-cli/test/smokehouse/perf/lantern-expectations.js

@@ -0,0 +1,27 @@
+/**
+ * @license Copyright 2017 Google Inc. All Rights Reserved.
+ * 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.
+ */
+'use strict';
+
+/**
+ * Expected Lighthouse audit values for lantern smoketests
+ */
+module.exports = [
+  {
+    requestedUrl: 'http://localhost:10200/online-only.html',
+    finalUrl: 'http://localhost:10200/online-only.html',
+    audits: {
+      'first-contentful-paint': {
+        rawValue: '>2000',
+      },
+      'first-cpu-idle': {
+        rawValue: '>2000',
+      },
+      'interactive': {
+        rawValue: '>2000',
+      },
+    },
+  },
+];

lighthouse-cli/test/smokehouse/run-smoke.js

@@ -80,6 +80,11 @@ const SMOKETESTS = [{
   expectations: 'perf/expectations.js',
   config: 'lighthouse-core/config/perf-config.js',
   batch: 'perf-metric',
+}, {
+  id: 'lantern',
+  expectations: 'perf/lantern-expectations.js',
+  config: smokehouseDir + 'lantern-config.js',
+  batch: 'parallel-first',
 }, {
   id: 'metrics',
   expectations: 'tricky-metrics/expectations.js',

lighthouse-core/computed/load-simulator.js

@@ -17,7 +17,7 @@ class LoadSimulator {
    * @return {Promise<Simulator>}
    */
   static async compute_(data, context) {
-    const {throttlingMethod, throttling} = data.settings;
+    const {throttlingMethod, throttling, precomputedLanternData} = data.settings;
     const networkAnalysis = await NetworkAnalysis.request(data.devtoolsLog, context);
 
     /** @type {LH.Gatherer.Simulation.Options} */
@@ -26,6 +26,13 @@ class LoadSimulator {
       serverResponseTimeByOrigin: networkAnalysis.serverResponseTimeByOrigin,
     };
 
+    if (precomputedLanternData) {
+      options.additionalRttByOrigin = new Map(Object.entries(
+        precomputedLanternData.additionalRttByOrigin));
+      options.serverResponseTimeByOrigin = new Map(Object.entries(
+        precomputedLanternData.serverResponseTimeByOrigin));
+    }
+
     switch (throttlingMethod) {
       case 'provided':
         options.rtt = networkAnalysis.rtt;

lighthouse-core/config/constants.js

@@ -57,6 +57,7 @@ const defaultSettings = {
   blockedUrlPatterns: null,
   additionalTraceCategories: null,
   extraHeaders: null,
+  precomputedLanternData: null,
   onlyAudits: null,
   onlyCategories: null,
   skipAudits: null,

lighthouse-core/lib/asset-saver.js

@@ -9,11 +9,12 @@ const fs = require('fs');
 const path = require('path');
 const log = require('lighthouse-logger');
 const stream = require('stream');
-const Simulator = require('./dependency-graph/simulator/simulator');
-const lanternTraceSaver = require('./lantern-trace-saver');
-const Metrics = require('./traces/pwmetrics-events');
+const Simulator = require('./dependency-graph/simulator/simulator.js');
+const lanternTraceSaver = require('./lantern-trace-saver.js');
+const Metrics = require('./traces/pwmetrics-events.js');
 const rimraf = require('rimraf');
 const mkdirp = require('mkdirp');
+const NetworkAnalysisComputed = require('../computed/network-analysis.js');
 
 const artifactsFilename = 'artifacts.json';
 const traceSuffix = '.trace.json';
@@ -272,11 +273,34 @@ async function logAssets(artifacts, audits) {
   });
 }
 
+/**
+ * @param {LH.DevtoolsLog} devtoolsLog
+ * @param {string} outputPath
+ * @return {Promise<void>}
+ */
+async function saveLanternNetworkData(devtoolsLog, outputPath) {
+  const context = /** @type {LH.Audit.Context} */ ({computedCache: new Map()});
+  const networkAnalysis = await NetworkAnalysisComputed.request(devtoolsLog, context);
+
+  /** @type {LH.PrecomputedLanternData} */
+  const lanternData = {additionalRttByOrigin: {}, serverResponseTimeByOrigin: {}};
+  for (const [origin, value] of networkAnalysis.additionalRttByOrigin.entries()) {
+    if (origin.startsWith('http')) lanternData.additionalRttByOrigin[origin] = value;
+  }
+
+  for (const [origin, value] of networkAnalysis.serverResponseTimeByOrigin.entries()) {
+    if (origin.startsWith('http')) lanternData.serverResponseTimeByOrigin[origin] = value;
+  }
+
+  fs.writeFileSync(outputPath, JSON.stringify(lanternData));
+}
+
 module.exports = {
   saveArtifacts,
   loadArtifacts,
   saveAssets,
   prepareAssets,
   saveTrace,
   logAssets,
+  saveLanternNetworkData,
 };

lighthouse-core/test/computed/load-simulator-test.js

@@ -10,6 +10,14 @@
 const assert = require('assert');
 const devtoolsLog = require('../fixtures/traces/progressive-app-m60.devtools.log.json');
 const LoadSimulator = require('../../computed/load-simulator.js');
+const NetworkNode = require('../../lib/dependency-graph/network-node.js');
+
+function createNetworkNode() {
+  return new NetworkNode({
+    requestId: '1',
+    parsedURL: {securityOrigin: 'https://pwa.rocks'},
+  });
+}
 
 describe('Simulator artifact', () => {
   it('returns a simulator for "provided" throttling', async () => {
@@ -45,14 +53,52 @@ describe('Simulator artifact', () => {
     const throttling = {rttMs: 120, throughputKbps: 1000, cpuSlowdownMultiplier: 3};
     const settings = {throttlingMethod: 'simulate', throttling};
     const context = {settings, computedCache: new Map()};
-    const simulator = await LoadSimulator.request({
-      devtoolsLog,
-      settings,
-    }, context);
+    const simulator = await LoadSimulator.request({devtoolsLog, settings}, context);
 
     assert.equal(simulator._rtt, 120);
     assert.equal(simulator._throughput / 1024, 1000);
     assert.equal(simulator._cpuSlowdownMultiplier, 3);
     assert.equal(simulator._layoutTaskMultiplier, 1.5);
+    simulator.simulate(createNetworkNode());
+
+    const {additionalRttByOrigin, serverResponseTimeByOrigin} = simulator._connectionPool._options;
+    expect(additionalRttByOrigin.get('https://pwa.rocks')).toMatchInlineSnapshot(
+      `0.3960000176447025`
+    );
+    expect(serverResponseTimeByOrigin.get('https://pwa.rocks')).toMatchInlineSnapshot(
+      `159.42199996789026`
+    );
+  });
+
+  it('returns a simulator with precomputed lantern data', async () => {
+    const precomputedLanternData = {
+      additionalRttByOrigin: {
+        'https://pwa.rocks': 1000,
+        'https://www.googletagmanager.com': 500,
+        'https://www.google-analytics.com': 1000,
+      },
+      serverResponseTimeByOrigin: {
+        'https://pwa.rocks': 150,
+        'https://www.googletagmanager.com': 200,
+        'https://www.google-analytics.com': 400,
+      },
+    };
+
+    const settings = {throttlingMethod: 'simulate', precomputedLanternData};
+    const context = {settings, computedCache: new Map()};
+    const simulator = await LoadSimulator.request({devtoolsLog, settings}, context);
+    simulator.simulate(createNetworkNode());
+
+    const {additionalRttByOrigin, serverResponseTimeByOrigin} = simulator._connectionPool._options;
+    expect(additionalRttByOrigin).toEqual(new Map([
+      ['https://pwa.rocks', 1000],
+      ['https://www.googletagmanager.com', 500],
+      ['https://www.google-analytics.com', 1000],
+    ]));
+    expect(serverResponseTimeByOrigin).toEqual(new Map([
+      ['https://pwa.rocks', 150],
+      ['https://www.googletagmanager.com', 200],
+      ['https://www.google-analytics.com', 400],
+    ]));
   });
 });

lighthouse-core/test/lib/asset-saver-test.js

@@ -15,6 +15,7 @@ const dbwTrace = require('../results/artifacts/defaultPass.trace.json');
 const dbwResults = require('../results/sample_v2.json');
 const Audit = require('../../audits/audit.js');
 const fullTraceObj = require('../fixtures/traces/progressive-app-m60.json');
+const devtoolsLog = require('../fixtures/traces/progressive-app-m60.devtools.log.json');
 
 // deepStrictEqual can hang on a full trace, we assert trace same-ness like so
 function assertTraceEventsEqual(traceEventsA, traceEventsB) {
@@ -165,4 +166,31 @@ describe('asset-saver helper', () => {
       assert.strictEqual(artifacts.traces.defaultPass.traceEvents.length, 12);
     });
   });
+
+  describe('saveLanternNetworkData', () => {
+    const outputFilename = 'test-lantern-network-data.json';
+
+    afterEach(() => {
+      fs.unlinkSync(outputFilename);
+    });
+
+    it('saves the network analysis to disk', async () => {
+      await assetSaver.saveLanternNetworkData(devtoolsLog, outputFilename);
+
+      const results = JSON.parse(fs.readFileSync(outputFilename, 'utf8'));
+
+      expect(results).toEqual({
+        additionalRttByOrigin: {
+          'https://pwa.rocks': expect.any(Number),
+          'https://www.google-analytics.com': expect.any(Number),
+          'https://www.googletagmanager.com': expect.any(Number),
+        },
+        serverResponseTimeByOrigin: {
+          'https://pwa.rocks': expect.any(Number),
+          'https://www.google-analytics.com': expect.any(Number),
+          'https://www.googletagmanager.com': expect.any(Number),
+        },
+      });
+    });
+  });
 });

lighthouse-core/test/results/sample_v2.json

@@ -3171,6 +3171,7 @@
     "blockedUrlPatterns": null,
     "additionalTraceCategories": null,
     "extraHeaders": null,
+    "precomputedLanternData": null,
     "onlyAudits": null,
     "onlyCategories": null,
     "skipAudits": null

types/externs.d.ts

@@ -75,6 +75,11 @@ declare global {
       cpuSlowdownMultiplier?: number
     }
 
+    export interface PrecomputedLanternData {
+      additionalRttByOrigin: {[origin: string]: number};
+      serverResponseTimeByOrigin: {[origin: string]: number};
+    }
+
     export type Locale = 'en-US'|'en'|'en-AU'|'en-GB'|'en-IE'|'en-SG'|'en-ZA'|'en-IN'|'ar-XB'|'ar'|'bg'|'bs'|'ca'|'cs'|'da'|'de'|'el'|'en-XA'|'es'|'fi'|'fil'|'fr'|'he'|'hi'|'hr'|'hu'|'gsw'|'id'|'in'|'it'|'iw'|'ja'|'ko'|'ln'|'lt'|'lv'|'mo'|'nl'|'nb'|'no'|'pl'|'pt'|'pt-PT'|'ro'|'ru'|'sk'|'sl'|'sr'|'sr-Latn'|'sv'|'ta'|'te'|'th'|'tl'|'tr'|'uk'|'vi'|'zh'|'zh-HK'|'zh-TW';
 
     export type OutputMode = 'json' | 'html' | 'csv';
@@ -116,6 +121,8 @@ declare global {
       skipAudits?: string[] | null;
       // List of extra HTTP Headers to include
       extraHeaders?: Crdp.Network.Headers | null; // See extraHeaders TODO in bin.js
+      // Precomputed lantern estimates to use instead of observed analysis
+      precomputedLanternData?: PrecomputedLanternData | null;
     }
 
     /**
@@ -157,6 +164,10 @@ declare global {
       port: number;
       hostname: string;
       printConfig: boolean;
+      // Path to the file where precomputed lantern data should be read from.
+      precomputedLanternDataPath?: string;
+      // Path to the file where precomputed lantern data should be written to.
+      lanternDataOutputPath?: string;
     }
 
     export interface RunnerResult {