jormungandr-bite/src/misc/before-shutdown.ts
MeiMei b2dfd27588 ランダムにテストがコケるのを修正 (#7553)
* Test shutdown

* Revert "Test shutdown"

This reverts commit 85182e7dd196cdd9ecb46cfb50adaabd04c5ba60.

* Skip beforeShutdown in test

* Wait shutdown in test

* Revert "Skip beforeShutdown in test"

This reverts commit 79c33ab53615e8fa4820d2abfc2494cba55c441c.

* Revert "Revert "Skip beforeShutdown in test""

This reverts commit 3423133a137c79b64f3ff6ef9dbe433a441a47b0.
2021-06-05 14:54:07 +09:00

92 lines
2.9 KiB
TypeScript

// https://gist.github.com/nfantone/1eaa803772025df69d07f4dbf5df7e58
'use strict';
/**
* @callback BeforeShutdownListener
* @param {string} [signalOrEvent] The exit signal or event name received on the process.
*/
/**
* System signals the app will listen to initiate shutdown.
* @const {string[]}
*/
const SHUTDOWN_SIGNALS = ['SIGINT', 'SIGTERM'];
/**
* Time in milliseconds to wait before forcing shutdown.
* @const {number}
*/
const SHUTDOWN_TIMEOUT = 15000;
/**
* A queue of listener callbacks to execute before shutting
* down the process.
* @type {BeforeShutdownListener[]}
*/
const shutdownListeners = [];
/**
* Listen for signals and execute given `fn` function once.
* @param {string[]} signals System signals to listen to.
* @param {function(string)} fn Function to execute on shutdown.
*/
const processOnce = (signals, fn) => {
for (const sig of signals) {
process.once(sig, fn);
}
};
/**
* Sets a forced shutdown mechanism that will exit the process after `timeout` milliseconds.
* @param {number} timeout Time to wait before forcing shutdown (milliseconds)
*/
const forceExitAfter = timeout => () => {
setTimeout(() => {
// Force shutdown after timeout
console.warn(`Could not close resources gracefully after ${timeout}ms: forcing shutdown`);
return process.exit(1);
}, timeout).unref();
};
/**
* Main process shutdown handler. Will invoke every previously registered async shutdown listener
* in the queue and exit with a code of `0`. Any `Promise` rejections from any listener will
* be logged out as a warning, but won't prevent other callbacks from executing.
* @param {string} signalOrEvent The exit signal or event name received on the process.
*/
async function shutdownHandler(signalOrEvent) {
if (process.env.NODE_ENV === 'test') return process.exit(0);
console.warn(`Shutting down: received [${signalOrEvent}] signal`);
for (const listener of shutdownListeners) {
try {
await listener(signalOrEvent);
} catch (err) {
console.warn(`A shutdown handler failed before completing with: ${err.message || err}`);
}
}
return process.exit(0);
}
/**
* Registers a new shutdown listener to be invoked before exiting
* the main process. Listener handlers are guaranteed to be called in the order
* they were registered.
* @param {BeforeShutdownListener} listener The shutdown listener to register.
* @returns {BeforeShutdownListener} Echoes back the supplied `listener`.
*/
export function beforeShutdown(listener) {
shutdownListeners.push(listener);
return listener;
}
// Register shutdown callback that kills the process after `SHUTDOWN_TIMEOUT` milliseconds
// This prevents custom shutdown handlers from hanging the process indefinitely
processOnce(SHUTDOWN_SIGNALS, forceExitAfter(SHUTDOWN_TIMEOUT));
// Register process shutdown callback
// Will listen to incoming signal events and execute all registered handlers in the stack
processOnce(SHUTDOWN_SIGNALS, shutdownHandler);