tra-analysis/website/functions/node_modules/write-file-atomic/index.js
2019-01-06 13:14:45 -06:00

200 lines
5.8 KiB
JavaScript

'use strict'
module.exports = writeFile
module.exports.sync = writeFileSync
module.exports._getTmpname = getTmpname // for testing
module.exports._cleanupOnExit = cleanupOnExit
var fs = require('graceful-fs')
var MurmurHash3 = require('imurmurhash')
var onExit = require('signal-exit')
var path = require('path')
var activeFiles = {}
var invocations = 0
function getTmpname (filename) {
return filename + '.' +
MurmurHash3(__filename)
.hash(String(process.pid))
.hash(String(++invocations))
.result()
}
function cleanupOnExit (tmpfile) {
return function () {
try {
fs.unlinkSync(typeof tmpfile === 'function' ? tmpfile() : tmpfile)
} catch (_) {}
}
}
function writeFile (filename, data, options, callback) {
if (options instanceof Function) {
callback = options
options = null
}
if (!options) options = {}
var Promise = options.Promise || global.Promise
var truename
var fd
var tmpfile
var removeOnExit = cleanupOnExit(() => tmpfile)
var absoluteName = path.resolve(filename)
new Promise(function serializeSameFile (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
}).then(function getRealPath () {
return new Promise(function (resolve) {
fs.realpath(filename, function (_, realname) {
truename = realname || filename
tmpfile = getTmpname(truename)
resolve()
})
})
}).then(function stat () {
return new Promise(function stat (resolve) {
if (options.mode && options.chown) resolve()
else {
// Either mode or chown is not explicitly set
// Default behavior is to copy it from original file
fs.stat(truename, function (err, stats) {
if (err || !stats) resolve()
else {
options = Object.assign({}, options)
if (!options.mode) {
options.mode = stats.mode
}
if (!options.chown && process.getuid) {
options.chown = { uid: stats.uid, gid: stats.gid }
}
resolve()
}
})
}
})
}).then(function thenWriteFile () {
return new Promise(function (resolve, reject) {
fs.open(tmpfile, 'w', options.mode, function (err, _fd) {
fd = _fd
if (err) reject(err)
else resolve()
})
})
}).then(function write () {
return new Promise(function (resolve, reject) {
if (Buffer.isBuffer(data)) {
fs.write(fd, data, 0, data.length, 0, function (err) {
if (err) reject(err)
else resolve()
})
} else if (data != null) {
fs.write(fd, String(data), 0, String(options.encoding || 'utf8'), function (err) {
if (err) reject(err)
else resolve()
})
} else resolve()
})
}).then(function syncAndClose () {
if (options.fsync !== false) {
return new Promise(function (resolve, reject) {
fs.fsync(fd, function (err) {
if (err) reject(err)
else fs.close(fd, resolve)
})
})
}
}).then(function chown () {
if (options.chown) {
return new Promise(function (resolve, reject) {
fs.chown(tmpfile, options.chown.uid, options.chown.gid, function (err) {
if (err) reject(err)
else resolve()
})
})
}
}).then(function chmod () {
if (options.mode) {
return new Promise(function (resolve, reject) {
fs.chmod(tmpfile, options.mode, function (err) {
if (err) reject(err)
else resolve()
})
})
}
}).then(function rename () {
return new Promise(function (resolve, reject) {
fs.rename(tmpfile, truename, function (err) {
if (err) reject(err)
else resolve()
})
})
}).then(function success () {
removeOnExit()
callback()
}).catch(function fail (err) {
removeOnExit()
fs.unlink(tmpfile, function () {
callback(err)
})
}).then(function checkQueue () {
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 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 = 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
}
}
var removeOnExit = onExit(cleanupOnExit(tmpfile))
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'))
}
if (options.fsync !== false) {
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)
removeOnExit()
} catch (err) {
removeOnExit()
try { fs.unlinkSync(tmpfile) } catch (e) {}
throw err
}
}