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// META: timeout=long
// META: script=/resources/test-only-api.js
// META: script=resources/pressure-helpers.js
// META: global=window,dedicatedworker,sharedworker
'use strict';
pressure_test(async (t, mockPressureService) => {
const sampleIntervalInMs = 100;
const readings = ['nominal', 'fair', 'serious', 'critical'];
// Normative values for rate obfuscation parameters.
// https://w3c.github.io/compute-pressure/#rate-obfuscation-normative-parameters.
const minPenaltyTimeInMs = 5000;
const minChangesThreshold = 50;
const changes = await new Promise(async resolve => {
const observerChanges = [];
const observer = new PressureObserver(changes => {
observerChanges.push(changes);
});
observer.observe('cpu', {sampleInterval: sampleIntervalInMs});
mockPressureService.startPlatformCollector(sampleIntervalInMs);
let i = 0;
// mockPressureService.updatesDelivered() does not necessarily match
// pressureChanges.length, as system load and browser optimizations can
// cause the actual timer used by mockPressureService to deliver readings
// to be a bit slower or faster than requested.
while (observerChanges.length < minChangesThreshold) {
mockPressureService.setPressureUpdate(
'cpu', readings[i++ % readings.length]);
// Allow tasks to run (avoid a micro-task loop).
await new Promise((resolve) => t.step_timeout(resolve, 0));
await t.step_wait(
() => mockPressureService.updatesDelivered() >= i,
`At least ${i} readings have been delivered`);
}
observer.disconnect();
resolve(observerChanges);
});
assert_equals(changes.length, minChangesThreshold);
for (let i = 0; i < (changes.length - 1); i++) {
// Because no penalty should be triggered, the timestamp difference
// between samples should be less than the minimum penalty.
assert_less_than(
changes[i + 1][0].time - changes[i][0].time, minPenaltyTimeInMs,
'Not in sample time boundaries');
}
}, 'No rate obfuscation mitigation should happen, when number of changes is below minimum changes before penalty');
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