chromium/src/third_party/blink/web_tests/http/tests/devtools/isolated-code-cache/same-origin-test.js

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

(async function() {
  TestRunner.addResult(`Tests V8 code cache for javascript resources\n`);
  await TestRunner.loadModule('performance_test_runner');
  await TestRunner.showPanel('timeline');

  // Clear browser cache to avoid any existing entries for the fetched
  // scripts in the cache.
  SDK.multitargetNetworkManager.clearBrowserCache();

  // There are two scripts:
  // [A] http://127.0.0.1:8000/devtools/resources/v8-cache-script.cgi
  // [B] http://localhost:8000/devtools/resources/v8-cache-script.cgi

  // An iframe that loads [A].
  // The script is executed as a parser-inserted script,
  // to keep the ScriptResource on the MemoryCache.
  // ScriptResources for dynamically-inserted <script>s can be
  // garbage-collected and thus removed from MemoryCache after its execution.
  const scope = 'resources/same-origin-script.html';
  // An iframe that loads [B].
  const scopeCrossOrigin = 'resources/cross-origin-script.html';

  TestRunner.addResult('--- Trace events related to code caches ------');
  await PerformanceTestRunner.startTimeline();

  async function stopAndPrintTimeline() {
    await PerformanceTestRunner.stopTimeline();
    await PerformanceTestRunner.printTimelineRecordsWithDetails(
        TimelineModel.TimelineModel.RecordType.CompileScript);
  }

  async function expectationComment(msg) {
    await stopAndPrintTimeline();
    TestRunner.addResult(msg);
    await PerformanceTestRunner.startTimeline();
  }

  // Load [A] thrice. With the current V8 heuristics (defined in
  // third_party/blink/renderer/bindings/core/v8/v8_code_cache.cc) we produce
  // cache on second fetch and consume it in the third fetch. This tests these
  // heuristics.
  // Note that addIframe() waits for iframe's load event, which waits for the
  // <script> loading.
  await expectationComment('Load [A] 1st time. Produce timestamp. -->');
  await TestRunner.addIframe(scope);

  await expectationComment('Load [A] 2nd time. Produce code cache. -->');
  await TestRunner.addIframe(scope);

  await expectationComment('Load [A] 3rd time. Consume code cache. -->');
  await TestRunner.addIframe(scope);

  await expectationComment('Load [B]. Should not use the cached code. -->');
  await TestRunner.addIframe(scopeCrossOrigin);

  await expectationComment('Load [A] again from MemoryCache. ' +
      'Should use the cached code. -->');
  await TestRunner.addIframe(scope);

  await expectationComment('Clear [A] from MemoryCache. -->');
  // Blink evicts previous Resource when a new request to the same URL but with
  // different resource type is started.  We fetch() to the URL of [A], and thus
  // evicts the previous ScriptResource of [A].
  await TestRunner.evaluateInPageAsync(
      `fetch('/devtools/resources/v8-cache-script.cgi')`);

  await expectationComment('Load [A] from Disk Cache. -->');
  // As we cleared [A] from MemoryCache, this doesn't hit MemoryCache, but still
  // hits Disk Cache.
  await TestRunner.addIframe(scope);

  await stopAndPrintTimeline();
  TestRunner.addResult('-----------------------------------------------');
  TestRunner.completeTest();
})();