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2 years ago
'use strict'
module.exports = writeFile
module.exports.sync = writeFileSync
module.exports._getTmpname = getTmpname // for testing
module.exports._cleanupOnExit = cleanupOnExit
const fs = require('fs')
const MurmurHash3 = require('imurmurhash')
const onExit = require('signal-exit')
const path = require('path')
const isTypedArray = require('is-typedarray')
const typedArrayToBuffer = require('typedarray-to-buffer')
const { promisify } = require('util')
const activeFiles = {}
// if we run inside of a worker_thread, `process.pid` is not unique
/* istanbul ignore next */
const threadId = (function getId () {
try {
const workerThreads = require('worker_threads')
/// if we are in main thread, this is set to `0`
return workerThreads.threadId
} catch (e) {
// worker_threads are not available, fallback to 0
return 0
}
})()
let invocations = 0
function getTmpname (filename) {
return filename + '.' +
MurmurHash3(__filename)
.hash(String(process.pid))
.hash(String(threadId))
.hash(String(++invocations))
.result()
}
function cleanupOnExit (tmpfile) {
return () => {
try {
fs.unlinkSync(typeof tmpfile === 'function' ? tmpfile() : tmpfile)
} catch (_) {}
}
}
function serializeActiveFile (absoluteName) {
return new Promise(resolve => {
// make a queue if it doesn't already exist
if (!activeFiles[absoluteName]) activeFiles[absoluteName] = []
activeFiles[absoluteName].push(resolve) // add this job to the queue
if (activeFiles[absoluteName].length === 1) resolve() // kick off the first one
})
}
// https://github.com/isaacs/node-graceful-fs/blob/master/polyfills.js#L315-L342
function isChownErrOk (err) {
if (err.code === 'ENOSYS') {
return true
}
const nonroot = !process.getuid || process.getuid() !== 0
if (nonroot) {
if (err.code === 'EINVAL' || err.code === 'EPERM') {
return true
}
}
return false
}
async function writeFileAsync (filename, data, options = {}) {
if (typeof options === 'string') {
options = { encoding: options }
}
let fd
let tmpfile
/* istanbul ignore next -- The closure only gets called when onExit triggers */
const removeOnExitHandler = onExit(cleanupOnExit(() => tmpfile))
const absoluteName = path.resolve(filename)
try {
await serializeActiveFile(absoluteName)
const truename = await promisify(fs.realpath)(filename).catch(() => filename)
tmpfile = getTmpname(truename)
if (!options.mode || !options.chown) {
// Either mode or chown is not explicitly set
// Default behavior is to copy it from original file
const stats = await promisify(fs.stat)(truename).catch(() => {})
if (stats) {
if (options.mode == null) {
options.mode = stats.mode
}
if (options.chown == null && process.getuid) {
options.chown = { uid: stats.uid, gid: stats.gid }
}
}
}
fd = await promisify(fs.open)(tmpfile, 'w', options.mode)
if (options.tmpfileCreated) {
await options.tmpfileCreated(tmpfile)
}
if (isTypedArray(data)) {
data = typedArrayToBuffer(data)
}
if (Buffer.isBuffer(data)) {
await promisify(fs.write)(fd, data, 0, data.length, 0)
} else if (data != null) {
await promisify(fs.write)(fd, String(data), 0, String(options.encoding || 'utf8'))
}
if (options.fsync !== false) {
await promisify(fs.fsync)(fd)
}
await promisify(fs.close)(fd)
fd = null
if (options.chown) {
await promisify(fs.chown)(tmpfile, options.chown.uid, options.chown.gid).catch(err => {
if (!isChownErrOk(err)) {
throw err
}
})
}
if (options.mode) {
await promisify(fs.chmod)(tmpfile, options.mode).catch(err => {
if (!isChownErrOk(err)) {
throw err
}
})
}
await promisify(fs.rename)(tmpfile, truename)
} finally {
if (fd) {
await promisify(fs.close)(fd).catch(
/* istanbul ignore next */
() => {}
)
}
removeOnExitHandler()
await promisify(fs.unlink)(tmpfile).catch(() => {})
activeFiles[absoluteName].shift() // remove the element added by serializeSameFile
if (activeFiles[absoluteName].length > 0) {
activeFiles[absoluteName][0]() // start next job if one is pending
} else delete activeFiles[absoluteName]
}
}
function writeFile (filename, data, options, callback) {
if (options instanceof Function) {
callback = options
options = {}
}
const promise = writeFileAsync(filename, data, options)
if (callback) {
promise.then(callback, callback)
}
return promise
}
function writeFileSync (filename, data, options) {
if (typeof options === 'string') options = { encoding: options }
else if (!options) options = {}
try {
filename = fs.realpathSync(filename)
} catch (ex) {
// it's ok, it'll happen on a not yet existing file
}
const tmpfile = getTmpname(filename)
if (!options.mode || !options.chown) {
// Either mode or chown is not explicitly set
// Default behavior is to copy it from original file
try {
const stats = fs.statSync(filename)
options = Object.assign({}, options)
if (!options.mode) {
options.mode = stats.mode
}
if (!options.chown && process.getuid) {
options.chown = { uid: stats.uid, gid: stats.gid }
}
} catch (ex) {
// ignore stat errors
}
}
let fd
const cleanup = cleanupOnExit(tmpfile)
const removeOnExitHandler = onExit(cleanup)
let threw = true
try {
fd = fs.openSync(tmpfile, 'w', options.mode || 0o666)
if (options.tmpfileCreated) {
options.tmpfileCreated(tmpfile)
}
if (isTypedArray(data)) {
data = typedArrayToBuffer(data)
}
if (Buffer.isBuffer(data)) {
fs.writeSync(fd, data, 0, data.length, 0)
} else if (data != null) {
fs.writeSync(fd, String(data), 0, String(options.encoding || 'utf8'))
}
if (options.fsync !== false) {
fs.fsyncSync(fd)
}
fs.closeSync(fd)
fd = null
if (options.chown) {
try {
fs.chownSync(tmpfile, options.chown.uid, options.chown.gid)
} catch (err) {
if (!isChownErrOk(err)) {
throw err
}
}
}
if (options.mode) {
try {
fs.chmodSync(tmpfile, options.mode)
} catch (err) {
if (!isChownErrOk(err)) {
throw err
}
}
}
fs.renameSync(tmpfile, filename)
threw = false
} finally {
if (fd) {
try {
fs.closeSync(fd)
} catch (ex) {
// ignore close errors at this stage, error may have closed fd already.
}
}
removeOnExitHandler()
if (threw) {
cleanup()
}
}
}