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'use strict'
module.exports = writeFile
module.exports.sync = writeFileSync
module.exports._getTmpname = getTmpname // for testing
var fs = require('graceful-fs')
var chain = require('slide').chain
var MurmurHash3 = require('imurmurhash')
var extend = Object.assign || require('util')._extend
var invocations = 0
function getTmpname (filename) {
return filename + '.' +
MurmurHash3(__filename)
.hash(String(process.pid))
.hash(String(++invocations))
.result()
}
function writeFile (filename, data, options, callback) {
if (options instanceof Function) {
callback = options
options = null
}
if (!options) options = {}
fs.realpath(filename, function (_, realname) {
_writeFile(realname || filename, data, options, callback)
})
}
function _writeFile (filename, data, options, callback) {
var tmpfile = getTmpname(filename)
if (options.mode && options.chown) {
return thenWriteFile()
} else {
// Either mode or chown is not explicitly set
// Default behavior is to copy it from original file
return fs.stat(filename, function (err, stats) {
if (err || !stats) return thenWriteFile()
options = extend({}, options)
if (!options.mode) {
options.mode = stats.mode
}
if (!options.chown && process.getuid) {
options.chown = { uid: stats.uid, gid: stats.gid }
}
return thenWriteFile()
})
}
function thenWriteFile () {
chain([
[fs, fs.writeFile, tmpfile, data, options.encoding || 'utf8'],
options.mode && [fs, fs.chmod, tmpfile, options.mode],
options.chown && [fs, fs.chown, tmpfile, options.chown.uid, options.chown.gid],
[fs, fs.rename, tmpfile, filename]
], function (err) {
err ? fs.unlink(tmpfile, function () { callback(err) })
: callback()
})
}
}
function writeFileSync (filename, data, options) {
if (!options) options = {}
try {
filename = fs.realpathSync(filename)
} catch (ex) {
// it's ok, it'll happen on a not yet existing file
}
var tmpfile = getTmpname(filename)
try {
if (!options.mode || !options.chown) {
// Either mode or chown is not explicitly set
// Default behavior is to copy it from original file
try {
var stats = fs.statSync(filename)
options = extend({}, 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
}
}
fs.writeFileSync(tmpfile, data, options.encoding || 'utf8')
if (options.chown) fs.chownSync(tmpfile, options.chown.uid, options.chown.gid)
if (options.mode) fs.chmodSync(tmpfile, options.mode)
fs.renameSync(tmpfile, filename)
} catch (err) {
try { fs.unlinkSync(tmpfile) } catch (e) {}
throw err
}
}