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1'use strict'
2module.exports = writeFile
3module.exports.sync = writeFileSync
4module.exports._getTmpname = getTmpname // for testing
5module.exports._cleanupOnExit = cleanupOnExit
6
7var fs = require('graceful-fs')
8var MurmurHash3 = require('imurmurhash')
9var onExit = require('signal-exit')
10var path = require('path')
11var activeFiles = {}
12
13// if we run inside of a worker_thread, `process.pid` is not unique
14/* istanbul ignore next */
15var threadId = (function getId () {
16  try {
17    var workerThreads = require('worker_threads')
18
19    /// if we are in main thread, this is set to `0`
20    return workerThreads.threadId
21  } catch (e) {
22    // worker_threads are not available, fallback to 0
23    return 0
24  }
25})()
26
27var invocations = 0
28function getTmpname (filename) {
29  return filename + '.' +
30    MurmurHash3(__filename)
31      .hash(String(process.pid))
32      .hash(String(threadId))
33      .hash(String(++invocations))
34      .result()
35}
36
37function cleanupOnExit (tmpfile) {
38  return function () {
39    try {
40      fs.unlinkSync(typeof tmpfile === 'function' ? tmpfile() : tmpfile)
41    } catch (_) {}
42  }
43}
44
45function writeFile (filename, data, options, callback) {
46  if (options) {
47    if (options instanceof Function) {
48      callback = options
49      options = {}
50    } else if (typeof options === 'string') {
51      options = { encoding: options }
52    }
53  } else {
54    options = {}
55  }
56
57  var Promise = options.Promise || global.Promise
58  var truename
59  var fd
60  var tmpfile
61  /* istanbul ignore next -- The closure only gets called when onExit triggers */
62  var removeOnExitHandler = onExit(cleanupOnExit(() => tmpfile))
63  var absoluteName = path.resolve(filename)
64
65  new Promise(function serializeSameFile (resolve) {
66    // make a queue if it doesn't already exist
67    if (!activeFiles[absoluteName]) activeFiles[absoluteName] = []
68
69    activeFiles[absoluteName].push(resolve) // add this job to the queue
70    if (activeFiles[absoluteName].length === 1) resolve() // kick off the first one
71  }).then(function getRealPath () {
72    return new Promise(function (resolve) {
73      fs.realpath(filename, function (_, realname) {
74        truename = realname || filename
75        tmpfile = getTmpname(truename)
76        resolve()
77      })
78    })
79  }).then(function stat () {
80    return new Promise(function stat (resolve) {
81      if (options.mode && options.chown) resolve()
82      else {
83        // Either mode or chown is not explicitly set
84        // Default behavior is to copy it from original file
85        fs.stat(truename, function (err, stats) {
86          if (err || !stats) resolve()
87          else {
88            options = Object.assign({}, options)
89
90            if (options.mode == null) {
91              options.mode = stats.mode
92            }
93            if (options.chown == null && process.getuid) {
94              options.chown = { uid: stats.uid, gid: stats.gid }
95            }
96            resolve()
97          }
98        })
99      }
100    })
101  }).then(function thenWriteFile () {
102    return new Promise(function (resolve, reject) {
103      fs.open(tmpfile, 'w', options.mode, function (err, _fd) {
104        fd = _fd
105        if (err) reject(err)
106        else resolve()
107      })
108    })
109  }).then(function write () {
110    return new Promise(function (resolve, reject) {
111      if (Buffer.isBuffer(data)) {
112        fs.write(fd, data, 0, data.length, 0, function (err) {
113          if (err) reject(err)
114          else resolve()
115        })
116      } else if (data != null) {
117        fs.write(fd, String(data), 0, String(options.encoding || 'utf8'), function (err) {
118          if (err) reject(err)
119          else resolve()
120        })
121      } else resolve()
122    })
123  }).then(function syncAndClose () {
124    return new Promise(function (resolve, reject) {
125      if (options.fsync !== false) {
126        fs.fsync(fd, function (err) {
127          if (err) fs.close(fd, () => reject(err))
128          else fs.close(fd, resolve)
129        })
130      } else {
131        fs.close(fd, resolve)
132      }
133    })
134  }).then(function chown () {
135    fd = null
136    if (options.chown) {
137      return new Promise(function (resolve, reject) {
138        fs.chown(tmpfile, options.chown.uid, options.chown.gid, function (err) {
139          if (err) reject(err)
140          else resolve()
141        })
142      })
143    }
144  }).then(function chmod () {
145    if (options.mode) {
146      return new Promise(function (resolve, reject) {
147        fs.chmod(tmpfile, options.mode, function (err) {
148          if (err) reject(err)
149          else resolve()
150        })
151      })
152    }
153  }).then(function rename () {
154    return new Promise(function (resolve, reject) {
155      fs.rename(tmpfile, truename, function (err) {
156        if (err) reject(err)
157        else resolve()
158      })
159    })
160  }).then(function success () {
161    removeOnExitHandler()
162    callback()
163  }, function fail (err) {
164    return new Promise(resolve => {
165      return fd ? fs.close(fd, resolve) : resolve()
166    }).then(() => {
167      removeOnExitHandler()
168      fs.unlink(tmpfile, function () {
169        callback(err)
170      })
171    })
172  }).then(function checkQueue () {
173    activeFiles[absoluteName].shift() // remove the element added by serializeSameFile
174    if (activeFiles[absoluteName].length > 0) {
175      activeFiles[absoluteName][0]() // start next job if one is pending
176    } else delete activeFiles[absoluteName]
177  })
178}
179
180function writeFileSync (filename, data, options) {
181  if (typeof options === 'string') options = { encoding: options }
182  else if (!options) options = {}
183  try {
184    filename = fs.realpathSync(filename)
185  } catch (ex) {
186    // it's ok, it'll happen on a not yet existing file
187  }
188  var tmpfile = getTmpname(filename)
189
190  if (!options.mode || !options.chown) {
191    // Either mode or chown is not explicitly set
192    // Default behavior is to copy it from original file
193    try {
194      var stats = fs.statSync(filename)
195      options = Object.assign({}, options)
196      if (!options.mode) {
197        options.mode = stats.mode
198      }
199      if (!options.chown && process.getuid) {
200        options.chown = { uid: stats.uid, gid: stats.gid }
201      }
202    } catch (ex) {
203      // ignore stat errors
204    }
205  }
206
207  var fd
208  var cleanup = cleanupOnExit(tmpfile)
209  var removeOnExitHandler = onExit(cleanup)
210
211  try {
212    fd = fs.openSync(tmpfile, 'w', options.mode)
213    if (Buffer.isBuffer(data)) {
214      fs.writeSync(fd, data, 0, data.length, 0)
215    } else if (data != null) {
216      fs.writeSync(fd, String(data), 0, String(options.encoding || 'utf8'))
217    }
218    if (options.fsync !== false) {
219      fs.fsyncSync(fd)
220    }
221    fs.closeSync(fd)
222    if (options.chown) fs.chownSync(tmpfile, options.chown.uid, options.chown.gid)
223    if (options.mode) fs.chmodSync(tmpfile, options.mode)
224    fs.renameSync(tmpfile, filename)
225    removeOnExitHandler()
226  } catch (err) {
227    if (fd) {
228      try {
229        fs.closeSync(fd)
230      } catch (ex) {
231        // ignore close errors at this stage, error may have closed fd already.
232      }
233    }
234    removeOnExitHandler()
235    cleanup()
236    throw err
237  }
238}
239