map-get-object.js - mozsearch

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// Similar test as "cacheir/map-get-object.js", except that we now perform

// duplicate lookups to ensure GVN works properly.

// Return a new map, possibly filling some dummy entries to enforce creating

// multiple hash buckets.

function createMap(values, n) {

  var xs = [...values];

  for (var i = 0; i < n; ++i) {

    xs.push({});

  return new Map(xs.map((x, i) => [x, i + 1]));

function runTest(fn) {

  fn(0);

  fn(100);

function test_same_map(n) {

  var xs = [{}, {}];

  var ys = [{}, {}];

  var zs = [...xs, ...ys];

  var map = createMap(xs, n);

  var N = 100;

  var c = 0;

  for (var i = 0; i < N; ++i) {

    var z = zs[i & 3];

    var v = map.get(z);

    if (v !== undefined) c += v;

    var w = map.get(z);

    if (w !== undefined) c += w;

  assertEq(c, N + N / 2);

runTest(test_same_map);

// Duplicate the above tests, but this time use a different map.

function test_different_map(n) {

  var xs = [{}, {}];

  var ys = [{}, {}];

  var zs = [...xs, ...ys];

  var map1 = createMap(xs, n);

  var map2 = createMap(xs, n);

  var N = 100;

  var c = 0;

  for (var i = 0; i < N; ++i) {

    var z = zs[i & 3];

    var v = map1.get(z);

    if (v !== undefined) c += v;

    var w = map2.get(z);

    if (w !== undefined) c += w;

  assertEq(c, N + N / 2);

runTest(test_different_map);

// Test the alias information is correct.

function test_alias(n) {

  var xs = [{}, {}];

  var map = createMap([], n);

  var N = 100;

  var c = 0;

  for (var i = 0; i < N; ++i) {

    var x = xs[i & 1];

    map.set(x, 1);

    var v = map.get(x);

    map.delete(x);

    var w = map.get(x);

    c += v;

    assertEq(w, undefined);

  assertEq(c, N);

runTest(test_alias);

// And finally test that we don't actually support GVN for objects, because the

// hash changes when moving an object.

function testRekey() {

  var map = new Map();

  var c = 0;

  var N = 100;

  for (var i = 0; i < N; ++i) {

    var k = {};

    map.set(k, 1);

    c += map.get(k);

    minorgc();

    c += map.get(k);

  assertEq(c, N * 2);

testRekey();