GT2/GT2-iOS/node_modules/write-file-atomic/index.js

130 lines
3.8 KiB
JavaScript

'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([
[writeFileAsync, tmpfile, data, options.mode, options.encoding || 'utf8'],
options.chown && [fs, fs.chown, tmpfile, options.chown.uid, options.chown.gid],
options.mode && [fs, fs.chmod, tmpfile, options.mode],
[fs, fs.rename, tmpfile, filename]
], function (err) {
err ? fs.unlink(tmpfile, function () { callback(err) })
: callback()
})
}
// doing this instead of `fs.writeFile` in order to get the ability to
// call `fsync`.
function writeFileAsync (file, data, mode, encoding, cb) {
fs.open(file, 'w', options.mode, function (err, fd) {
if (err) return cb(err)
if (Buffer.isBuffer(data)) {
return fs.write(fd, data, 0, data.length, 0, syncAndClose)
} else if (data != null) {
return fs.write(fd, String(data), 0, String(encoding), syncAndClose)
} else {
return syncAndClose()
}
function syncAndClose (err) {
if (err) return cb(err)
fs.fsync(fd, function (err) {
if (err) return cb(err)
fs.close(fd, cb)
})
}
})
}
}
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
}
}
var fd = fs.openSync(tmpfile, 'w', options.mode)
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'))
}
fs.fsyncSync(fd)
fs.closeSync(fd)
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
}
}