Files
infocom-systems-design/node_modules/on-exit-leak-free/index.js
2025-10-03 22:27:28 +03:00

109 lines
1.9 KiB
JavaScript

'use strict'
const refs = {
exit: [],
beforeExit: []
}
const functions = {
exit: onExit,
beforeExit: onBeforeExit
}
let registry
function ensureRegistry () {
if (registry === undefined) {
registry = new FinalizationRegistry(clear)
}
}
function install (event) {
if (refs[event].length > 0) {
return
}
process.on(event, functions[event])
}
function uninstall (event) {
if (refs[event].length > 0) {
return
}
process.removeListener(event, functions[event])
if (refs.exit.length === 0 && refs.beforeExit.length === 0) {
registry = undefined
}
}
function onExit () {
callRefs('exit')
}
function onBeforeExit () {
callRefs('beforeExit')
}
function callRefs (event) {
for (const ref of refs[event]) {
const obj = ref.deref()
const fn = ref.fn
// This should always happen, however GC is
// undeterministic so it might not happen.
/* istanbul ignore else */
if (obj !== undefined) {
fn(obj, event)
}
}
refs[event] = []
}
function clear (ref) {
for (const event of ['exit', 'beforeExit']) {
const index = refs[event].indexOf(ref)
refs[event].splice(index, index + 1)
uninstall(event)
}
}
function _register (event, obj, fn) {
if (obj === undefined) {
throw new Error('the object can\'t be undefined')
}
install(event)
const ref = new WeakRef(obj)
ref.fn = fn
ensureRegistry()
registry.register(obj, ref)
refs[event].push(ref)
}
function register (obj, fn) {
_register('exit', obj, fn)
}
function registerBeforeExit (obj, fn) {
_register('beforeExit', obj, fn)
}
function unregister (obj) {
if (registry === undefined) {
return
}
registry.unregister(obj)
for (const event of ['exit', 'beforeExit']) {
refs[event] = refs[event].filter((ref) => {
const _obj = ref.deref()
return _obj && _obj !== obj
})
uninstall(event)
}
}
module.exports = {
register,
registerBeforeExit,
unregister
}