71 lines
1.7 KiB
JavaScript
71 lines
1.7 KiB
JavaScript
const cache = new Map()
|
|
const fs = require('fs')
|
|
const { dirname, resolve } = require('path')
|
|
|
|
|
|
const lstat = path => new Promise((res, rej) =>
|
|
fs.lstat(path, (er, st) => er ? rej(er) : res(st)))
|
|
|
|
const inferOwner = path => {
|
|
path = resolve(path)
|
|
if (cache.has(path))
|
|
return Promise.resolve(cache.get(path))
|
|
|
|
const statThen = st => {
|
|
const { uid, gid } = st
|
|
cache.set(path, { uid, gid })
|
|
return { uid, gid }
|
|
}
|
|
const parent = dirname(path)
|
|
const parentTrap = parent === path ? null : er => {
|
|
return inferOwner(parent).then((owner) => {
|
|
cache.set(path, owner)
|
|
return owner
|
|
})
|
|
}
|
|
return lstat(path).then(statThen, parentTrap)
|
|
}
|
|
|
|
const inferOwnerSync = path => {
|
|
path = resolve(path)
|
|
if (cache.has(path))
|
|
return cache.get(path)
|
|
|
|
const parent = dirname(path)
|
|
|
|
// avoid obscuring call site by re-throwing
|
|
// "catch" the error by returning from a finally,
|
|
// only if we're not at the root, and the parent call works.
|
|
let threw = true
|
|
try {
|
|
const st = fs.lstatSync(path)
|
|
threw = false
|
|
const { uid, gid } = st
|
|
cache.set(path, { uid, gid })
|
|
return { uid, gid }
|
|
} finally {
|
|
if (threw && parent !== path) {
|
|
const owner = inferOwnerSync(parent)
|
|
cache.set(path, owner)
|
|
return owner // eslint-disable-line no-unsafe-finally
|
|
}
|
|
}
|
|
}
|
|
|
|
const inflight = new Map()
|
|
module.exports = path => {
|
|
path = resolve(path)
|
|
if (inflight.has(path))
|
|
return Promise.resolve(inflight.get(path))
|
|
const p = inferOwner(path).then(owner => {
|
|
inflight.delete(path)
|
|
return owner
|
|
})
|
|
inflight.set(path, p)
|
|
return p
|
|
}
|
|
module.exports.sync = inferOwnerSync
|
|
module.exports.clearCache = () => {
|
|
cache.clear()
|
|
inflight.clear()
|
|
}
|