excalidraw/src/networkStats.ts
Panayiotis Lipiridis aaf4943fa3 Average speed
2021-02-07 15:51:12 +02:00

53 lines
1.2 KiB
TypeScript

const IMAGE_URL = `${process.env.REACT_APP_SOCKET_SERVER_URL}/test256.png`;
const IMAGE_SIZE_BITS = 141978 * 8;
const AVERAGE_MAX = 4;
const speedHistory: number[] = [];
const pushSpeed = (speed: number): void => {
speedHistory.push(speed);
if (speedHistory.length > AVERAGE_MAX) {
speedHistory.shift();
}
};
const getAverageSpeed = (): number => {
return speedHistory.reduce((a, b) => a + b) / speedHistory.length;
};
const getSpeedBits = (
imageSize: number,
startTime: number,
endTime: number,
): number => {
const duration = (endTime - startTime) / 1000;
if (duration > 0) {
return imageSize / duration;
}
return 0;
};
const processImage = (): Promise<number> => {
return new Promise((resolve) => {
const image = new Image();
let endTime: number;
image.onload = () => {
endTime = new Date().getTime();
const speed = getSpeedBits(IMAGE_SIZE_BITS, startTime, endTime);
pushSpeed(speed);
resolve(getAverageSpeed());
};
image.onerror = () => {
resolve(-1);
};
const startTime = new Date().getTime();
image.src = `${IMAGE_URL}?t=${startTime}`;
});
};
export const getNetworkSpeed = async (): Promise<number> => {
return await processImage();
};