Web latency - headless
/*
* Performs a dirty `fetch` to a RIPE Atlas anchor
*/
fetch_anchor = async (anchor, samples = constants().samples) => {
console.log(`https://${anchor}/`);
let dirty_rtts = [];
let bytes_rx = 0;
for (let i of [...Array(samples).keys()]) {
let t0 = new Date();
let rtt_tcp = await fetch(
// anchor's fqdn over HTTPS (with the new LE's cetificates)
`https://${anchor}/`,
{
mode: "no-cors"
}
);
let dt = new Date() - t0;
await wait(1000 - dt);
dirty_rtts.push(dt);
console.log(`rtt=${dt}ms`);
mutable total_bytes_rx += 255;
mutable requests_done++;
}
return { min: Math.min(...dirty_rtts), rtts: dirty_rtts };
}
select_points = (level) => {
let user_input = parseFloat(level); // 1.0;
let user_country_selection = {};
let points_by_country = group_array(mutable points, "country");
for (let [key, country_points] of Object.entries(points_by_country)) {
user_country_selection[key] = country_points.slice(
0,
Math.floor(country_points.length * user_input)
);
}
return Object.values(user_country_selection).flat();
}
measure = async (level) => {
// button;
let min = 1000;
mutable test_count = 0;
mutable requests_done = 0;
mutable total_bytes_rx = 0;
for (let point of select_points(level)) {
mutable current_point = point;
let res = await fetch_anchor(point.fqdn);
point.rtts ? point.rtts.push(res.min) : (point.rtts = [res.min]);
if (res.min < min) {
min = res.min;
mutable closest_point = point;
}
mutable test_count++;
await Promises.tick(1000);
}
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
