tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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map-has-object.js (1872B)

      1 // Similar test as "cacheir/map-has-object.js", except that we now perform
      2 // duplicate lookups to ensure GVN works properly.
      3 
      4 // Return a new map, possibly filling some dummy entries to enforce creating
      5 // multiple hash buckets.
      6 function createMap(values, n) {
      7  var xs = [...values];
      8  for (var i = 0; i < n; ++i) {
      9    xs.push({});
     10  }
     11  return new Map(xs.map((x, i) => [x, i]));
     12 }
     13 
     14 function runTest(fn) {
     15  fn(0);
     16  fn(100);
     17 }
     18 
     19 function test_same_map(n) {
     20  var xs = [{}, {}];
     21  var ys = [{}, {}];
     22  var zs = [...xs, ...ys];
     23  var map = createMap(xs, n);
     24 
     25  var N = 100;
     26  var c = 0;
     27  for (var i = 0; i < N; ++i) {
     28    var z = zs[i & 3];
     29    if (map.has(z)) c++;
     30    if (map.has(z)) c++;
     31  }
     32  assertEq(c, N);
     33 }
     34 runTest(test_same_map);
     35 
     36 // Duplicate the above tests, but this time use a different map.
     37 
     38 function test_different_map(n) {
     39  var xs = [{}, {}];
     40  var ys = [{}, {}];
     41  var zs = [...xs, ...ys];
     42  var map1 = createMap(xs, n);
     43  var map2 = createMap(xs, n);
     44 
     45  var N = 100;
     46  var c = 0;
     47  for (var i = 0; i < N; ++i) {
     48    var z = zs[i & 3];
     49    if (map1.has(z)) c++;
     50    if (map2.has(z)) c++;
     51  }
     52  assertEq(c, N);
     53 }
     54 runTest(test_different_map);
     55 
     56 // Test the alias information is correct.
     57 
     58 function test_alias(n) {
     59  var xs = [{}, {}];
     60  var map = createMap([], n);
     61 
     62  var N = 100;
     63  var c = 0;
     64  for (var i = 0; i < N; ++i) {
     65    var x = xs[i & 1];
     66 
     67    map.set(x, x);
     68    if (map.has(x)) c++;
     69 
     70    map.delete(x);
     71    if (map.has(x)) c++;
     72  }
     73  assertEq(c, N);
     74 }
     75 runTest(test_alias);
     76 
     77 // And finally test that we don't actually support GVN for objects, because the
     78 // hash changes when moving an object.
     79 
     80 function testRekey() {
     81  var map = new Map();
     82  var c = 0;
     83  var N = 100;
     84  for (var i = 0; i < N; ++i) {
     85    var k = {};
     86    map.set(k, i);
     87 
     88    if (map.has(k)) c++;
     89 
     90    minorgc();
     91 
     92    if (map.has(k)) c++;
     93  }
     94 
     95  assertEq(c, N * 2);
     96 }
     97 testRekey();