feat: Initial clean release of CHM

packages/lib/ntp.ts

@@ -0,0 +1,85 @@
+import shim from './shim';
+import time from './time';
+const ntpClient_ = require('./vendor/ntp-client');
+
+interface NtpServer {
+	domain: string;
+	port: number;
+}
+
+function ntpClient() {
+	ntpClient_.dgram = shim.dgram();
+	return ntpClient_;
+}
+
+const parseNtpServer = (ntpServer: string): NtpServer => {
+	const s = ntpServer.split(':');
+	if (s.length !== 2) throw new Error('NTP server URL must be in format `domain:port`');
+	return {
+		domain: s[0],
+		port: Number(s[1]),
+	};
+};
+
+export async function getNetworkTime(ntpServer: string): Promise<Date> {
+	return new Promise<Date>((resolve, reject) => {
+		const s = parseNtpServer(ntpServer);
+		ntpClient().getNetworkTime(s.domain, s.port, (error: Error | null, date: Date) => {
+			if (error) {
+				reject(error);
+				return;
+			}
+
+			resolve(date);
+		});
+	});
+}
+
+export async function getDeviceTimeDrift(ntpServer: string): Promise<number> {
+	const maxTries = 3;
+	let tryCount = 0;
+
+	let ntpTime: Date = null;
+
+	while (true) {
+		tryCount++;
+		try {
+			ntpTime = await getNetworkTime(ntpServer);
+			break;
+		} catch (error) {
+			if (tryCount >= maxTries) {
+				const newError = typeof error === 'string' ? new Error(error) : error;
+				newError.message = `Cannot retrieve the network time from ${ntpServer}: ${newError.message}`;
+				throw newError;
+			} else {
+				await time.msleep(tryCount * 1000);
+			}
+		}
+	}
+
+	return ntpTime.getTime() - Date.now();
+}
+
+// export default async function(): Promise<Date> {
+// 	if (shouldSyncTime()) {
+// 		const release = await fetchingTimeMutex.acquire();
+
+// 		try {
+// 			if (shouldSyncTime()) {
+// 				const date = await networkTime();
+// 				nextSyncTime = Date.now() + 60 * 1000;
+// 				timeOffset = date.getTime() - Date.now();
+// 			}
+// 		} catch (error) {
+// 			logger.warn('Could not get NTP time - falling back to device time:', error);
+// 			// Fallback to device time since
+// 			// most of the time it's actually correct
+// 			nextSyncTime = Date.now() + 20 * 1000;
+// 			timeOffset = 0;
+// 		} finally {
+// 			release();
+// 		}
+// 	}
+
+// 	return new Date(Date.now() + timeOffset);
+// }