code-server/src/node/heart.ts

58 lines
1.5 KiB
TypeScript

import { logger } from "@coder/logger"
import { promises as fs } from "fs"
/**
* Provides a heartbeat using a local file to indicate activity.
*/
export class Heart {
private heartbeatTimer?: NodeJS.Timeout
private heartbeatInterval = 60000
public lastHeartbeat = 0
public constructor(private readonly heartbeatPath: string, private readonly isActive: () => Promise<boolean>) {}
public alive(): boolean {
const now = Date.now()
return now - this.lastHeartbeat < this.heartbeatInterval
}
/**
* Write to the heartbeat file if we haven't already done so within the
* timeout and start or reset a timer that keeps running as long as there is
* activity. Failures are logged as warnings.
*/
public beat(): void {
if (this.alive()) {
return
}
logger.trace("heartbeat")
fs.writeFile(this.heartbeatPath, "").catch((error) => {
logger.warn(error.message)
})
this.lastHeartbeat = Date.now()
if (typeof this.heartbeatTimer !== "undefined") {
clearTimeout(this.heartbeatTimer)
}
this.heartbeatTimer = setTimeout(() => {
this.isActive()
.then((active) => {
if (active) {
this.beat()
}
})
.catch((error) => {
logger.warn(error.message)
})
}, this.heartbeatInterval)
}
/**
* Call to clear any heartbeatTimer for shutdown.
*/
public dispose(): void {
if (typeof this.heartbeatTimer !== "undefined") {
clearTimeout(this.heartbeatTimer)
}
}
}