integrate amazing-graceful-fs with graceful-fs

all credit goes to ben
https://github.com/bnoordhuis/amazing-graceful-fs
and nodejs/node#2026

formatting was modified to match

Author: heavyk

fs.js

@@ -1,11 +1,21 @@
-// eeeeeevvvvviiiiiiillllll
-// more evil than monkey-patching the native builtin?
-// Not sure.
-
-var mod = require("module")
-var pre = '(function (exports, require, module, __filename, __dirname) { '
-var post = '});'
-var src = pre + process.binding('natives').fs + post
-var vm = require('vm')
-var fn = vm.runInThisContext(src)
-fn(exports, require, module, __filename, __dirname)
+'use strict'
+
+var fs = require('fs')
+
+module.exports = clone(fs)
+
+function clone (obj) {
+  if (obj === null || typeof obj !== 'object')
+    return obj
+
+  if ('__proto__' in obj)
+    var copy = { __proto__: obj.__proto__ }
+  else
+    var copy = Object.create(null)
+
+  Object.getOwnPropertyNames(obj).forEach(function (key) {
+    Object.defineProperty(copy, key, Object.getOwnPropertyDescriptor(obj, key))
+  })
+
+  return copy
+}

graceful-fs.js

@@ -1,158 +1,148 @@
-// Monkey-patching the fs module.
-// It's ugly, but there is simply no other way to do this.
-var fs = module.exports = require('./fs.js')
-
-var assert = require('assert')
+var fs = require('fs')
+module.exports = require('./fs.js')
 
 // fix up some busted stuff, mostly on windows and old nodes
 require('./polyfills.js')
 
-var util = require('util')
+module.exports.FileReadStream = ReadStream;  // Legacy name.
+module.exports.FileWriteStream = WriteStream;  // Legacy name.
+module.exports.ReadStream = ReadStream
+module.exports.WriteStream = WriteStream
+module.exports.close = close
+module.exports.closeSync = closeSync
+module.exports.createReadStream = createReadStream
+module.exports.createWriteStream = createWriteStream
+module.exports.open = open
+module.exports.readFile = readFile
+module.exports.readdir = readdir
 
-function noop () {}
+ReadStream.prototype = Object.create(fs.ReadStream.prototype)
+ReadStream.prototype.open = ReadStream$open
 
-var debug = noop
-if (util.debuglog)
-  debug = util.debuglog('gfs')
-else if (/\bgfs\b/i.test(process.env.NODE_DEBUG || ''))
-  debug = function() {
-    var m = util.format.apply(util, arguments)
-    m = 'GFS: ' + m.split(/\n/).join('\nGFS: ')
-    console.error(m)
-  }
+WriteStream.prototype = Object.create(fs.WriteStream.prototype)
+WriteStream.prototype.open = WriteStream$open
 
-if (/\bgfs\b/i.test(process.env.NODE_DEBUG || '')) {
-  process.on('exit', function() {
-    debug('fds', fds)
-    debug(queue)
-    assert.equal(queue.length, 0)
-  })
-}
-
-
-var originalOpen = fs.open
-fs.open = open
+var queue = []
 
-function open(path, flags, mode, cb) {
-  if (typeof mode === "function") cb = mode, mode = null
-  if (typeof cb !== "function") cb = noop
-  new OpenReq(path, flags, mode, cb)
+function ReadStream (path, options) {
+  if (this instanceof ReadStream)
+    return fs.ReadStream.apply(this, arguments), this
+  else
+    return ReadStream.apply(Object.create(ReadStream.prototype), arguments)
 }
 
-function OpenReq(path, flags, mode, cb) {
-  this.path = path
-  this.flags = flags
-  this.mode = mode
-  this.cb = cb
-  Req.call(this)
+function ReadStream$open () {
+  var that = this
+  open(that.path, that.flags, that.mode, function (err, fd) {
+    if (err) {
+      if (that.autoClose)
+        that.destroy()
+
+      that.emit('error', err)
+    } else {
+      that.fd = fd
+      that.emit('open', fd)
+      that.read()
+    }
+  })
 }
 
-util.inherits(OpenReq, Req)
-
-OpenReq.prototype.process = function() {
-  originalOpen.call(fs, this.path, this.flags, this.mode, this.done)
+function WriteStream (path, options) {
+  if (this instanceof WriteStream)
+    return fs.WriteStream.apply(this, arguments), this
+  else
+    return WriteStream.apply(Object.create(WriteStream.prototype), arguments)
 }
 
-var fds = {}
-OpenReq.prototype.done = function(er, fd) {
-  debug('open done', er, fd)
-  if (fd)
-    fds['fd' + fd] = this.path
-  Req.prototype.done.call(this, er, fd)
+function WriteStream$open () {
+  var that = this
+  open(that.path, that.flags, that.mode, function (err, fd) {
+    if (err) {
+      that.destroy()
+      that.emit('error', err)
+    } else {
+      that.fd = fd
+      that.emit('open', fd)
+    }
+  })
 }
 
+function close (fd, cb) {
+  return fs.close(fd, function (err) {
+    if (!err)
+      retry()
 
-var originalReaddir = fs.readdir
-fs.readdir = readdir
-
-function readdir(path, cb) {
-  if (typeof cb !== "function") cb = noop
-  new ReaddirReq(path, cb)
+    if (typeof cb === 'function')
+      cb.apply(this, arguments)
+  })
 }
 
-function ReaddirReq(path, cb) {
-  this.path = path
-  this.cb = cb
-  Req.call(this)
+function closeSync () {
+  // Note that graceful-fs also retries when fs.closeSync() fails.
+  // Looks like a bug to me, although it's probably a harmless one.
+  var rval = fs.closeSync.apply(fs, arguments)
+  retry()
+  return rval
 }
 
-util.inherits(ReaddirReq, Req)
-
-ReaddirReq.prototype.process = function() {
-  originalReaddir.call(fs, this.path, this.done)
+function createReadStream (path, options) {
+  return new ReadStream(path, options)
 }
 
-ReaddirReq.prototype.done = function(er, files) {
-  if (files && files.sort)
-    files = files.sort()
-  Req.prototype.done.call(this, er, files)
-  onclose()
+function createWriteStream (path, options) {
+  return new WriteStream(path, options)
 }
 
+function open (path, flags, mode, cb) {
+  if (typeof mode === 'function')
+    cb = mode, mode = null
 
-var originalClose = fs.close
-fs.close = close
+  return go(path, flags, mode, cb)
 
-function close (fd, cb) {
-  debug('close', fd)
-  if (typeof cb !== "function") cb = noop
-  delete fds['fd' + fd]
-  originalClose.call(fs, fd, function(er) {
-    onclose()
-    cb(er)
-  })
+  function go (path, flags, mode, cb) {
+    return fs.open(path, flags, mode, function (err, fd) {
+      if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
+        queue.push([go, [path, flags, mode, cb]])
+      else if (typeof cb === 'function')
+        cb.apply(this, arguments)
+    })
+  }
 }
 
+function readFile (path, options, cb) {
+  if (typeof options === 'function')
+    cb = options, options = null
 
-var originalCloseSync = fs.closeSync
-fs.closeSync = closeSync
+  return go(path, options, cb)
 
-function closeSync (fd) {
-  try {
-    return originalCloseSync(fd)
-  } finally {
-    onclose()
+  function go (path, flags, mode, cb) {
+    return fs.readFile(path, options, function (err, fd) {
+      if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
+        queue.push([go, [path, options, cb]])
+      else if (typeof cb === 'function')
+        cb.apply(this, arguments)
+    })
   }
 }
 
+function readdir (path, cb) {
+  return go(path, cb)
 
-// Req class
-function Req () {
-  // start processing
-  this.done = this.done.bind(this)
-  this.failures = 0
-  this.process()
-}
-
-Req.prototype.done = function (er, result) {
-  var tryAgain = false
-  if (er) {
-    var code = er.code
-    var tryAgain = code === "EMFILE" || code === "ENFILE"
-    if (process.platform === "win32")
-      tryAgain = tryAgain || code === "OK"
-  }
+  function go () {
+    return fs.readdir(path, function (err, files) {
+      if (files && files.sort)
+        files.sort();  // Backwards compatibility with graceful-fs.
 
-  if (tryAgain) {
-    this.failures ++
-    enqueue(this)
-  } else {
-    var cb = this.cb
-    cb(er, result)
+      if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
+        queue.push([go, [path, cb]])
+      else if (typeof cb === 'function')
+        cb.apply(this, arguments)
+    })
   }
 }
 
-var queue = []
-
-function enqueue(req) {
-  queue.push(req)
-  debug('enqueue %d %s', queue.length, req.constructor.name, req)
-}
-
-function onclose() {
-  var req = queue.shift()
-  if (req) {
-    debug('process', req.constructor.name, req)
-    req.process()
-  }
+function retry () {
+  var elem = queue.shift()
+  if (elem)
+    elem[0].apply(null, elem[1])
 }

test/open.js

@@ -1,10 +1,5 @@
 var test = require('tap').test
-var fs = require('../graceful-fs.js')
-
-test('graceful fs is monkeypatched fs', function (t) {
-  t.equal(fs, require('../fs.js'))
-  t.end()
-})
+var fs = require('../')
 
 test('open an existing file works', function (t) {
   var fd = fs.openSync(__filename, 'r')

test/read-write-stream.js

@@ -0,0 +1,58 @@
+'use strict'
+
+var fs = require('../')
+var rimraf = require('rimraf')
+var mkdirp = require('mkdirp')
+var test = require('tap').test
+var p = require('path').resolve(__dirname, 'files')
+
+process.chdir(__dirname)
+
+// Make sure to reserve the stderr fd
+process.stderr.write('')
+
+var num = 4097
+var paths = new Array(num)
+
+test('write files', function (t) {
+  rimraf.sync(p)
+  mkdirp.sync(p)
+
+  var done = 0
+  for (var i = 0; i < num; ++i) {
+    paths[i] = 'files/file-' + i
+    var stream = fs.createWriteStream(paths[i])
+    stream.on('end', function () {
+      ++done
+      if (done === num) {
+        t.pass('success')
+        t.end()
+      }
+    })
+    stream.write('content')
+    stream.end()
+  }
+
+  t.end()
+})
+
+test('read files', function (t) {
+  // now read them
+  var done = 0
+  for (var i = 0; i < num; ++i) {
+    var stream = fs.createReadStream(paths[i])
+    stream.on('data', function (data) {})
+    stream.on('end', function () {
+      ++done
+      if (done === num) {
+        t.pass('success')
+        t.end()
+      }
+    })
+  }
+})
+
+test('cleanup', function (t) {
+  rimraf.sync(p)
+  t.end()
+})

test/readdir-sort.js

@@ -1,5 +1,5 @@
 var test = require("tap").test
-var fs = require("../fs.js")
+var fs = require("fs")
 
 var readdir = fs.readdir
 fs.readdir = function(path, cb) {