#jsVanilla #webAPI Memory stat exp

https://busy-lace-heather.glitch.me/

// Schedules the next memory measurement using setTimeout with
// a randomized interval.
function scheduleMeasurement() {
  if (!performance.measureUserAgentSpecificMemory) {
    console.log(
      "performance.measureUserAgentSpecificMemory() is not available. " +
        "Currently only Chrome 85.0.4178.0+ supports it as an Origin Trial."
    );
    return;
  }
  const interval = measurementInterval();
  console.log(
    "Scheduling memory measurement in " +
      Math.round(interval / 1000) +
      " seconds."
  );
  setTimeout(performMeasurement, interval);
}

// Start measurements after page load on the main window.
window.onload = function() {
  scheduleMeasurement();
};

// Computes a random interval in milliseconds such that on
// average there is one measurement every five minutes.
// See https://bit.ly/3bR0hys for an explanation of the math.
function measurementInterval() {
  const MEAN_INTERVAL_IN_MS = 5 * 60 * 1000;
  return -Math.log(Math.random()) * MEAN_INTERVAL_IN_MS;
}

// Invokes the API, records the result, and schedules
// the next measurement.
async function performMeasurement() {
  // 1. Invoke performance.measureUserAgentSpecificMemory().
  let result;
  try {
    result = await performance.measureUserAgentSpecificMemory();
  } catch (error) {
    if (error instanceof DOMException && error.name === "SecurityError") {
      console.log("The context is not secure.");
      console.log(
        "Make sure that Site Isolation is enabled in Chrome " +
          "and that the page is not embedded as an iframe."
      );
      return;
    }
    // Rethrow other errors.
    throw error;
  }
  // 2. Record the result.
  console.log("Memory usage:", result);
  // 3. Schedule the next measurement.
  scheduleMeasurement();
}