20 lines
736 B
JavaScript
20 lines
736 B
JavaScript
const imageAddr = 'https://upload.wikimedia.org/wikipedia/commons/b/b9/Pizigani_1367_Chart_1MB.jpg';
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const downloadSize = 1093957; // this must match with the image above
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let startTime, endTime;
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async function measureConnectionSpeed() {
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startTime = new Date().getTime();
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const cacheBuster = '?nnn=' + startTime;
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const download = new Image();
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download.src = imageAddr + cacheBuster;
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// this returns when the image is finished downloading
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await download.decode();
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endTime = new Date().getTime();
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const duration = (endTime - startTime) / 1000;
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const bitsLoaded = downloadSize * 8;
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const speedBps = (bitsLoaded / duration).toFixed(2);
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return Math.round(Number(speedBps));
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}
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module.exports = measureConnectionSpeed;
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