src/third_party/WebKit/PerformanceTests/Layout/chapter-reflow-once-random.html

   1 <!DOCTYPE html>
   2 <html>
   3 <head>
   4     <title>Chapter reflow performance test: random text</title>
   5     <script src="../resources/runner.js"></script>
   6 </head>
   7 <body>
   8     <pre id="log"></pre>
   9     <div id="target" style="width: 300px; display: none;">
  10
  11     </div>
  12     <script>
  13         var RandomTextGenerator = function() {
  14             this.letters = [
  15                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  16                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  17                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  18                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  19                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  20                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  21                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  22                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  23                 String.fromCharCode(RandomTextGenerator.firstCharCode),
  24                 String.fromCharCode(RandomTextGenerator.firstCharCode)
  25             ]
  26         }
  27
  28         RandomTextGenerator.firstCharCode = 65; // 'A'
  29
  30         RandomTextGenerator.lastCharCode = 123; // 'z'
  31
  32         RandomTextGenerator.prototype.advance = function(index) {
  33             var charCode = this.letters[index].charCodeAt(0);
  34             var newCharCode = charCode + 1;
  35             if (newCharCode > RandomTextGenerator.lastCharCode)
  36                 newCharCode = RandomTextGenerator.firstCharCode;
  37             this.letters[index] = String.fromCharCode(newCharCode);
  38             return charCode;
  39         }
  40
  41         RandomTextGenerator.prototype.generate = function() {
  42             var result = this.letters.join("");
  43
  44             var index = 0;
  45             while (1) {
  46                 var charCode = this.advance(index);
  47                 if (charCode != RandomTextGenerator.lastCharCode)
  48                     break;
  49                 ++index;
  50             }
  51
  52             return result;
  53         }
  54
  55         var target = document.getElementById("target");
  56         var style = target.style;
  57         var randomTextGenerator = new RandomTextGenerator;
  58
  59         function test() {
  60             var target = document.getElementById("target");
  61             var style = target.style;
  62
  63             var innerHTML = "<p>";
  64             for (var i = 0; i < 5000; ++i)
  65                 innerHTML += randomTextGenerator.generate() + " ";
  66             innerHTML += "</p>";
  67             target.innerHTML = innerHTML;
  68
  69             style.display = "block";
  70             style.width = "280px";
  71             target.offsetLeft;
  72             style.display = "none";
  73         }
  74
  75         PerfTestRunner.measureRunsPerSecond({
  76             description: "Measures performance of 3 layouts (using 2 different font-sizes) on a page containing random text.",
  77             run: test
  78         });
  79     </script>
  80 </body>
  81 </html>