| <!doctype HTML> |
| |
| <!-- |
| This test appends 30,000 items to the page, locking all but the first one. |
| It then changes the style of an element contained inside each of the 30,000 |
| items. This changes the size, causing the children of locked elements to |
| need layout. |
| |
| The test works with and without display locking. If display locking is not |
| enabled, then none of the elements are locked and the performance should |
| be noticeably worse. |
| --> |
| |
| <head> |
| <script src="../resources/runner.js"></script> |
| <style> |
| .container { |
| contain: style layout; |
| width: 200px; |
| content-size: 100px; |
| } |
| .box { |
| background: blue; |
| overflow: hidden; |
| width: 100px; |
| height: 100px; |
| } |
| </style> |
| </head> |
| |
| <body> |
| <!-- node template from which to construct items --> |
| <template id="node_template"> |
| <div class="container"> |
| Lorem ipsum dolor sit amet, consectetur adipiscing elit. |
| Quisque ante dui, posuere at pretium suscipit, condimentum at augue. |
| <div class="box"> |
| Lorem ipsum dolor sit amet, consectetur adipiscing elit. |
| Quisque ante dui, posuere at pretium suscipit, condimentum at augue. |
| </div> |
| Lorem ipsum dolor sit amet, consectetur adipiscing elit. |
| Quisque ante dui, posuere at pretium suscipit, condimentum at augue. |
| </div> |
| </template> |
| </body> |
| |
| <script> |
| function construct(n) { |
| const specimen = document.importNode( |
| document.getElementById("node_template").content, true).firstElementChild; |
| for (let i = 0; i < n; ++i) { |
| const clone = specimen.cloneNode(true); |
| if (i > 0) |
| clone.style = "content-visibility: hidden-matchable"; |
| document.body.appendChild(clone); |
| } |
| } |
| |
| let sizes = ["100px", "150px"]; |
| let size_index = 0; |
| function changeStyle() { |
| document.styleSheets[0].rules[1].style.width = sizes[size_index]; |
| size_index = 1 - size_index; |
| } |
| |
| let testDone = false; |
| let startTime; |
| function runTest() { |
| if (startTime) { |
| PerfTestRunner.measureValueAsync(PerfTestRunner.now() - startTime); |
| PerfTestRunner.addRunTestEndMarker(); |
| } |
| if (testDone) |
| return; |
| |
| startTime = PerfTestRunner.now(); |
| PerfTestRunner.addRunTestEndMarker(); |
| |
| changeStyle(); |
| requestAnimationFrame(runTest); |
| } |
| |
| construct(30000); |
| |
| PerfTestRunner.startMeasureValuesAsync({ |
| unit: 'ms', |
| done: () => { testDone = true; }, |
| run: runTest, |
| warmUpCount: 3, |
| iterationCount: 5 |
| }); |
| |
| </script> |
