Merge branch 'ext-work'

1 files changed, 984 insertions, 0 deletions

diff --git a/toolkit/jetpack/sdk/io/fs.js b/toolkit/jetpack/sdk/io/fs.js
new file mode 100644
index 000000000..860a884a5
--- /dev/null
+++ b/toolkit/jetpack/sdk/io/fs.js
@@ -0,0 +1,984 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+module.metadata = {
+  "stability": "experimental"
+};
+
+const { Cc, Ci, CC } = require("chrome");
+
+const { setTimeout } = require("../timers");
+const { Stream, InputStream, OutputStream } = require("./stream");
+const { emit, on } = require("../event/core");
+const { Buffer } = require("./buffer");
+const { ns } = require("../core/namespace");
+const { Class } = require("../core/heritage");
+
+
+const nsILocalFile = CC("@mozilla.org/file/local;1", "nsILocalFile",
+                        "initWithPath");
+const FileOutputStream = CC("@mozilla.org/network/file-output-stream;1",
+                            "nsIFileOutputStream", "init");
+const FileInputStream = CC("@mozilla.org/network/file-input-stream;1",
+                           "nsIFileInputStream", "init");
+const BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",
+                             "nsIBinaryInputStream", "setInputStream");
+const BinaryOutputStream = CC("@mozilla.org/binaryoutputstream;1",
+                              "nsIBinaryOutputStream", "setOutputStream");
+const StreamPump = CC("@mozilla.org/network/input-stream-pump;1",
+                      "nsIInputStreamPump", "init");
+
+const { createOutputTransport, createInputTransport } =
+  Cc["@mozilla.org/network/stream-transport-service;1"].
+  getService(Ci.nsIStreamTransportService);
+
+const { OPEN_UNBUFFERED } = Ci.nsITransport;
+
+
+const { REOPEN_ON_REWIND, DEFER_OPEN } = Ci.nsIFileInputStream;
+const { DIRECTORY_TYPE, NORMAL_FILE_TYPE } = Ci.nsIFile;
+const { NS_SEEK_SET, NS_SEEK_CUR, NS_SEEK_END } = Ci.nsISeekableStream;
+
+const FILE_PERMISSION = 0o666;
+const PR_UINT32_MAX = 0xfffffff;
+// Values taken from:
+// http://mxr.mozilla.org/mozilla-central/source/nsprpub/pr/include/prio.h#615
+const PR_RDONLY =       0x01;
+const PR_WRONLY =       0x02;
+const PR_RDWR =         0x04;
+const PR_CREATE_FILE =  0x08;
+const PR_APPEND =       0x10;
+const PR_TRUNCATE =     0x20;
+const PR_SYNC =         0x40;
+const PR_EXCL =         0x80;
+
+const FLAGS = {
+  "r":                  PR_RDONLY,
+  "r+":                 PR_RDWR,
+  "w":                  PR_CREATE_FILE | PR_TRUNCATE | PR_WRONLY,
+  "w+":                 PR_CREATE_FILE | PR_TRUNCATE | PR_RDWR,
+  "a":                  PR_APPEND | PR_CREATE_FILE | PR_WRONLY,
+  "a+":                 PR_APPEND | PR_CREATE_FILE | PR_RDWR
+};
+
+function accessor() {
+  let map = new WeakMap();
+  return function(fd, value) {
+    if (value === null) map.delete(fd);
+    if (value !== undefined) map.set(fd, value);
+    return map.get(fd);
+  }
+}
+
+var nsIFile = accessor();
+var nsIFileInputStream = accessor();
+var nsIFileOutputStream = accessor();
+var nsIBinaryInputStream = accessor();
+var nsIBinaryOutputStream = accessor();
+
+// Just a contstant object used to signal that all of the file
+// needs to be read.
+const ALL = new String("Read all of the file");
+
+function isWritable(mode) {
+  return !!(mode & PR_WRONLY || mode & PR_RDWR);
+}
+function isReadable(mode) {
+  return !!(mode & PR_RDONLY || mode & PR_RDWR);
+}
+
+function isString(value) {
+  return typeof(value) === "string";
+}
+function isFunction(value) {
+  return typeof(value) === "function";
+}
+
+function toArray(enumerator) {
+  let value = [];
+  while(enumerator.hasMoreElements())
+    value.push(enumerator.getNext())
+  return value
+}
+
+function getFileName(file) {
+  return file.QueryInterface(Ci.nsIFile).leafName;
+}
+
+
+function remove(path, recursive) {
+  let fd = new nsILocalFile(path)
+  if (fd.exists()) {
+    fd.remove(recursive || false);
+  }
+  else {
+    throw FSError("remove", "ENOENT", 34, path);
+  }
+}
+
+/**
+ * Utility function to convert either an octal number or string
+ * into an octal number
+ * 0777 => 0o777
+ * "0644" => 0o644
+ */
+function Mode(mode, fallback) {
+  return isString(mode) ? parseInt(mode, 8) : mode || fallback;
+}
+function Flags(flag) {
+  return !isString(flag) ? flag :
+         FLAGS[flag] || Error("Unknown file open flag: " + flag);
+}
+
+
+function FSError(op, code, errno, path, file, line) {
+  let error = Error(code + ", " + op + " " + path, file, line);
+  error.code = code;
+  error.path = path;
+  error.errno = errno;
+  return error;
+}
+
+const ReadStream = Class({
+  extends: InputStream,
+  initialize: function initialize(path, options) {
+    this.position = -1;
+    this.length = -1;
+    this.flags = "r";
+    this.mode = FILE_PERMISSION;
+    this.bufferSize = 64 * 1024;
+
+    options = options || {};
+
+    if ("flags" in options && options.flags)
+      this.flags = options.flags;
+    if ("bufferSize" in options && options.bufferSize)
+      this.bufferSize = options.bufferSize;
+    if ("length" in options && options.length)
+      this.length = options.length;
+    if ("position" in options && options.position !== undefined)
+      this.position = options.position;
+
+    let { flags, mode, position, length } = this;
+    let fd = isString(path) ? openSync(path, flags, mode) : path;
+    this.fd = fd;
+
+    let input = nsIFileInputStream(fd);
+    // Setting a stream position, unless it"s `-1` which means current position.
+    if (position >= 0)
+      input.QueryInterface(Ci.nsISeekableStream).seek(NS_SEEK_SET, position);
+    // We use `nsIStreamTransportService` service to transform blocking
+    // file input stream into a fully asynchronous stream that can be written
+    // without blocking the main thread.
+    let transport = createInputTransport(input, position, length, false);
+    // Open an input stream on a transport. We don"t pass flags to guarantee
+    // non-blocking stream semantics. Also we use defaults for segment size &
+    // count.
+    InputStream.prototype.initialize.call(this, {
+      asyncInputStream: transport.openInputStream(null, 0, 0)
+    });
+
+    // Close file descriptor on end and destroy the stream.
+    on(this, "end", _ => {
+      this.destroy();
+      emit(this, "close");
+    });
+
+    this.read();
+  },
+  destroy: function() {
+    closeSync(this.fd);
+    InputStream.prototype.destroy.call(this);
+  }
+});
+exports.ReadStream = ReadStream;
+exports.createReadStream = function createReadStream(path, options) {
+  return new ReadStream(path, options);
+};
+
+const WriteStream = Class({
+  extends: OutputStream,
+  initialize: function initialize(path, options) {
+    this.drainable = true;
+    this.flags = "w";
+    this.position = -1;
+    this.mode = FILE_PERMISSION;
+
+    options = options || {};
+
+    if ("flags" in options && options.flags)
+      this.flags = options.flags;
+    if ("mode" in options && options.mode)
+      this.mode = options.mode;
+    if ("position" in options && options.position !== undefined)
+      this.position = options.position;
+
+    let { position, flags, mode } = this;
+    // If pass was passed we create a file descriptor out of it. Otherwise
+    // we just use given file descriptor.
+    let fd = isString(path) ? openSync(path, flags, mode) : path;
+    this.fd = fd;
+
+    let output = nsIFileOutputStream(fd);
+    // Setting a stream position, unless it"s `-1` which means current position.
+    if (position >= 0)
+      output.QueryInterface(Ci.nsISeekableStream).seek(NS_SEEK_SET, position);
+    // We use `nsIStreamTransportService` service to transform blocking
+    // file output stream into a fully asynchronous stream that can be written
+    // without blocking the main thread.
+    let transport = createOutputTransport(output, position, -1, false);
+    // Open an output stream on a transport. We don"t pass flags to guarantee
+    // non-blocking stream semantics. Also we use defaults for segment size &
+    // count.
+    OutputStream.prototype.initialize.call(this, {
+      asyncOutputStream: transport.openOutputStream(OPEN_UNBUFFERED, 0, 0),
+      output: output
+    });
+
+    // For write streams "finish" basically means close.
+    on(this, "finish", _ => {
+       this.destroy();
+       emit(this, "close");
+    });
+  },
+  destroy: function() {
+    OutputStream.prototype.destroy.call(this);
+    closeSync(this.fd);
+  }
+});
+exports.WriteStream = WriteStream;
+exports.createWriteStream = function createWriteStream(path, options) {
+  return new WriteStream(path, options);
+};
+
+const Stats = Class({
+  initialize: function initialize(path) {
+    let file = new nsILocalFile(path);
+    if (!file.exists()) throw FSError("stat", "ENOENT", 34, path);
+    nsIFile(this, file);
+  },
+  isDirectory: function() {
+    return nsIFile(this).isDirectory();
+  },
+  isFile: function() {
+    return nsIFile(this).isFile();
+  },
+  isSymbolicLink: function() {
+    return nsIFile(this).isSymlink();
+  },
+  get mode() {
+    return nsIFile(this).permissions;
+  },
+  get size() {
+    return nsIFile(this).fileSize;
+  },
+  get mtime() {
+    return nsIFile(this).lastModifiedTime;
+  },
+  isBlockDevice: function() {
+    return nsIFile(this).isSpecial();
+  },
+  isCharacterDevice: function() {
+    return nsIFile(this).isSpecial();
+  },
+  isFIFO: function() {
+    return nsIFile(this).isSpecial();
+  },
+  isSocket: function() {
+    return nsIFile(this).isSpecial();
+  },
+  // non standard
+  get exists() {
+    return nsIFile(this).exists();
+  },
+  get hidden() {
+    return nsIFile(this).isHidden();
+  },
+  get writable() {
+    return nsIFile(this).isWritable();
+  },
+  get readable() {
+    return nsIFile(this).isReadable();
+  }
+});
+exports.Stats = Stats;
+
+const LStats = Class({
+  extends: Stats,
+  get size() {
+    return this.isSymbolicLink() ? nsIFile(this).fileSizeOfLink :
+                                   nsIFile(this).fileSize;
+  },
+  get mtime() {
+    return this.isSymbolicLink() ? nsIFile(this).lastModifiedTimeOfLink :
+                                   nsIFile(this).lastModifiedTime;
+  },
+  // non standard
+  get permissions() {
+    return this.isSymbolicLink() ? nsIFile(this).permissionsOfLink :
+                                   nsIFile(this).permissions;
+  }
+});
+
+const FStat = Class({
+  extends: Stats,
+  initialize: function initialize(fd) {
+    nsIFile(this, nsIFile(fd));
+  }
+});
+
+function noop() {}
+function Async(wrapped) {
+  return function (path, callback) {
+    let args = Array.slice(arguments);
+    callback = args.pop();
+    // If node is not given a callback argument
+    // it just does not calls it.
+    if (typeof(callback) !== "function") {
+      args.push(callback);
+      callback = noop;
+    }
+    setTimeout(function() {
+      try {
+        var result = wrapped.apply(this, args);
+        if (result === undefined) callback(null);
+        else callback(null, result);
+      } catch (error) {
+        callback(error);
+      }
+    }, 0);
+  }
+}
+
+
+/**
+ * Synchronous rename(2)
+ */
+function renameSync(oldPath, newPath) {
+  let source = new nsILocalFile(oldPath);
+  let target = new nsILocalFile(newPath);
+  if (!source.exists()) throw FSError("rename", "ENOENT", 34, oldPath);
+  return source.moveTo(target.parent, target.leafName);
+};
+exports.renameSync = renameSync;
+
+/**
+ * Asynchronous rename(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var rename = Async(renameSync);
+exports.rename = rename;
+
+/**
+ * Test whether or not the given path exists by checking with the file system.
+ */
+function existsSync(path) {
+  return new nsILocalFile(path).exists();
+}
+exports.existsSync = existsSync;
+
+var exists = Async(existsSync);
+exports.exists = exists;
+
+/**
+ * Synchronous ftruncate(2).
+ */
+function truncateSync(path, length) {
+  let fd = openSync(path, "w");
+  ftruncateSync(fd, length);
+  closeSync(fd);
+}
+exports.truncateSync = truncateSync;
+
+/**
+ * Asynchronous ftruncate(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+function truncate(path, length, callback) {
+  open(path, "w", function(error, fd) {
+    if (error) return callback(error);
+    ftruncate(fd, length, function(error) {
+      if (error) {
+        closeSync(fd);
+        callback(error);
+      }
+      else {
+        close(fd, callback);
+      }
+    });
+  });
+}
+exports.truncate = truncate;
+
+function ftruncate(fd, length, callback) {
+  write(fd, new Buffer(length), 0, length, 0, function(error) {
+    callback(error);
+  });
+}
+exports.ftruncate = ftruncate;
+
+function ftruncateSync(fd, length = 0) {
+  writeSync(fd, new Buffer(length), 0, length, 0);
+}
+exports.ftruncateSync = ftruncateSync;
+
+function chownSync(path, uid, gid) {
+  throw Error("Not implemented yet!!");
+}
+exports.chownSync = chownSync;
+
+var chown = Async(chownSync);
+exports.chown = chown;
+
+function lchownSync(path, uid, gid) {
+  throw Error("Not implemented yet!!");
+}
+exports.lchownSync = chownSync;
+
+var lchown = Async(lchown);
+exports.lchown = lchown;
+
+/**
+ * Synchronous chmod(2).
+ */
+function chmodSync (path, mode) {
+  let file;
+  try {
+    file = new nsILocalFile(path);
+  } catch(e) {
+    throw FSError("chmod", "ENOENT", 34, path);
+  }
+
+  file.permissions = Mode(mode);
+}
+exports.chmodSync = chmodSync;
+/**
+ * Asynchronous chmod(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var chmod = Async(chmodSync);
+exports.chmod = chmod;
+
+/**
+ * Synchronous chmod(2).
+ */
+function fchmodSync(fd, mode) {
+  throw Error("Not implemented yet!!");
+};
+exports.fchmodSync = fchmodSync;
+/**
+ * Asynchronous chmod(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var fchmod = Async(fchmodSync);
+exports.fchmod = fchmod;
+
+
+/**
+ * Synchronous stat(2). Returns an instance of `fs.Stats`
+ */
+function statSync(path) {
+  return new Stats(path);
+};
+exports.statSync = statSync;
+
+/**
+ * Asynchronous stat(2). The callback gets two arguments (err, stats) where
+ * stats is a `fs.Stats` object. It looks like this:
+ */
+var stat = Async(statSync);
+exports.stat = stat;
+
+/**
+ * Synchronous lstat(2). Returns an instance of `fs.Stats`.
+ */
+function lstatSync(path) {
+  return new LStats(path);
+};
+exports.lstatSync = lstatSync;
+
+/**
+ * Asynchronous lstat(2). The callback gets two arguments (err, stats) where
+ * stats is a fs.Stats object. lstat() is identical to stat(), except that if
+ * path is a symbolic link, then the link itself is stat-ed, not the file that
+ * it refers to.
+ */
+var lstat = Async(lstatSync);
+exports.lstat = lstat;
+
+/**
+ * Synchronous fstat(2). Returns an instance of `fs.Stats`.
+ */
+function fstatSync(fd) {
+  return new FStat(fd);
+};
+exports.fstatSync = fstatSync;
+
+/**
+ * Asynchronous fstat(2). The callback gets two arguments (err, stats) where
+ * stats is a fs.Stats object.
+ */
+var fstat = Async(fstatSync);
+exports.fstat = fstat;
+
+/**
+ * Synchronous link(2).
+ */
+function linkSync(source, target) {
+  throw Error("Not implemented yet!!");
+};
+exports.linkSync = linkSync;
+
+/**
+ * Asynchronous link(2). No arguments other than a possible exception are given
+ * to the completion callback.
+ */
+var link = Async(linkSync);
+exports.link = link;
+
+/**
+ * Synchronous symlink(2).
+ */
+function symlinkSync(source, target) {
+  throw Error("Not implemented yet!!");
+};
+exports.symlinkSync = symlinkSync;
+
+/**
+ * Asynchronous symlink(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var symlink = Async(symlinkSync);
+exports.symlink = symlink;
+
+/**
+ * Synchronous readlink(2). Returns the resolved path.
+ */
+function readlinkSync(path) {
+  return new nsILocalFile(path).target;
+};
+exports.readlinkSync = readlinkSync;
+
+/**
+ * Asynchronous readlink(2). The callback gets two arguments
+ * `(error, resolvedPath)`.
+ */
+var readlink = Async(readlinkSync);
+exports.readlink = readlink;
+
+/**
+ * Synchronous realpath(2). Returns the resolved path.
+ */
+function realpathSync(path) {
+  return new nsILocalFile(path).path;
+};
+exports.realpathSync = realpathSync;
+
+/**
+ * Asynchronous realpath(2). The callback gets two arguments
+ * `(err, resolvedPath)`.
+ */
+var realpath = Async(realpathSync);
+exports.realpath = realpath;
+
+/**
+ * Synchronous unlink(2).
+ */
+var unlinkSync = remove;
+exports.unlinkSync = unlinkSync;
+
+/**
+ * Asynchronous unlink(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var unlink = Async(remove);
+exports.unlink = unlink;
+
+/**
+ * Synchronous rmdir(2).
+ */
+var rmdirSync = remove;
+exports.rmdirSync = rmdirSync;
+
+/**
+ * Asynchronous rmdir(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var rmdir = Async(rmdirSync);
+exports.rmdir = rmdir;
+
+/**
+ * Synchronous mkdir(2).
+ */
+function mkdirSync(path, mode) {
+  try {
+    return nsILocalFile(path).create(DIRECTORY_TYPE, Mode(mode));
+  } catch (error) {
+    // Adjust exception thorw to match ones thrown by node.
+    if (error.name === "NS_ERROR_FILE_ALREADY_EXISTS") {
+      let { fileName, lineNumber } = error;
+      error = FSError("mkdir", "EEXIST", 47, path, fileName, lineNumber);
+    }
+    throw error;
+  }
+};
+exports.mkdirSync = mkdirSync;
+
+/**
+ * Asynchronous mkdir(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var mkdir = Async(mkdirSync);
+exports.mkdir = mkdir;
+
+/**
+ * Synchronous readdir(3). Returns an array of filenames excluding `"."` and
+ * `".."`.
+ */
+function readdirSync(path) {
+  try {
+    return toArray(new nsILocalFile(path).directoryEntries).map(getFileName);
+  }
+  catch (error) {
+    // Adjust exception thorw to match ones thrown by node.
+    if (error.name === "NS_ERROR_FILE_TARGET_DOES_NOT_EXIST" ||
+        error.name === "NS_ERROR_FILE_NOT_FOUND")
+    {
+      let { fileName, lineNumber } = error;
+      error = FSError("readdir", "ENOENT", 34, path, fileName, lineNumber);
+    }
+    throw error;
+  }
+};
+exports.readdirSync = readdirSync;
+
+/**
+ * Asynchronous readdir(3). Reads the contents of a directory. The callback
+ * gets two arguments `(error, files)` where `files` is an array of the names
+ * of the files in the directory excluding `"."` and `".."`.
+ */
+var readdir = Async(readdirSync);
+exports.readdir = readdir;
+
+/**
+ * Synchronous close(2).
+ */
+ function closeSync(fd) {
+   let input = nsIFileInputStream(fd);
+   let output = nsIFileOutputStream(fd);
+
+   // Closing input stream and removing reference.
+   if (input) input.close();
+   // Closing output stream and removing reference.
+   if (output) output.close();
+
+   nsIFile(fd, null);
+   nsIFileInputStream(fd, null);
+   nsIFileOutputStream(fd, null);
+   nsIBinaryInputStream(fd, null);
+   nsIBinaryOutputStream(fd, null);
+};
+exports.closeSync = closeSync;
+/**
+ * Asynchronous close(2). No arguments other than a possible exception are
+ * given to the completion callback.
+ */
+var close = Async(closeSync);
+exports.close = close;
+
+/**
+ * Synchronous open(2).
+ */
+function openSync(aPath, aFlag, aMode) {
+  let [ fd, flags, mode, file ] =
+      [ { path: aPath }, Flags(aFlag), Mode(aMode), nsILocalFile(aPath) ];
+
+  nsIFile(fd, file);
+
+  // If trying to open file for just read that does not exists
+  // need to throw exception as node does.
+  if (!file.exists() && !isWritable(flags))
+    throw FSError("open", "ENOENT", 34, aPath);
+
+  // If we want to open file in read mode we initialize input stream.
+  if (isReadable(flags)) {
+    let input = FileInputStream(file, flags, mode, DEFER_OPEN);
+    nsIFileInputStream(fd, input);
+  }
+
+  // If we want to open file in write mode we initialize output stream for it.
+  if (isWritable(flags)) {
+    let output = FileOutputStream(file, flags, mode, DEFER_OPEN);
+    nsIFileOutputStream(fd, output);
+  }
+
+  return fd;
+}
+exports.openSync = openSync;
+/**
+ * Asynchronous file open. See open(2). Flags can be
+ * `"r", "r+", "w", "w+", "a"`, or `"a+"`. mode defaults to `0666`.
+ * The callback gets two arguments `(error, fd).
+ */
+var open = Async(openSync);
+exports.open = open;
+
+/**
+ * Synchronous version of buffer-based fs.write(). Returns the number of bytes
+ * written.
+ */
+function writeSync(fd, buffer, offset, length, position) {
+  if (length + offset > buffer.length) {
+    throw Error("Length is extends beyond buffer");
+  }
+  else if (length + offset !== buffer.length) {
+    buffer = buffer.slice(offset, offset + length);
+  }
+
+  let output = BinaryOutputStream(nsIFileOutputStream(fd));
+  nsIBinaryOutputStream(fd, output);
+  // We write content as a byte array as this will avoid any transcoding
+  // if content was a buffer.
+  output.writeByteArray(buffer.valueOf(), buffer.length);
+  output.flush();
+};
+exports.writeSync = writeSync;
+
+/**
+ * Write buffer to the file specified by fd.
+ *
+ * `offset` and `length` determine the part of the buffer to be written.
+ *
+ * `position` refers to the offset from the beginning of the file where this
+ * data should be written. If `position` is `null`, the data will be written
+ * at the current position. See pwrite(2).
+ *
+ * The callback will be given three arguments `(error, written, buffer)` where
+ * written specifies how many bytes were written into buffer.
+ *
+ * Note that it is unsafe to use `fs.write` multiple times on the same file
+ * without waiting for the callback.
+ */
+function write(fd, buffer, offset, length, position, callback) {
+  if (!Buffer.isBuffer(buffer)) {
+    // (fd, data, position, encoding, callback)
+    let encoding = null;
+    [ position, encoding, callback ] = Array.slice(arguments, 1);
+    buffer = new Buffer(String(buffer), encoding);
+    offset = 0;
+  } else if (length + offset > buffer.length) {
+    throw Error("Length is extends beyond buffer");
+  } else if (length + offset !== buffer.length) {
+    buffer = buffer.slice(offset, offset + length);
+  }
+
+  let writeStream = new WriteStream(fd, { position: position,
+                                          length: length });
+  writeStream.on("error", callback);
+  writeStream.write(buffer, function onEnd() {
+    writeStream.destroy();
+    if (callback)
+      callback(null, buffer.length, buffer);
+  });
+};
+exports.write = write;
+
+/**
+ * Synchronous version of string-based fs.read. Returns the number of
+ * bytes read.
+ */
+function readSync(fd, buffer, offset, length, position) {
+  let input = nsIFileInputStream(fd);
+  // Setting a stream position, unless it"s `-1` which means current position.
+  if (position >= 0)
+    input.QueryInterface(Ci.nsISeekableStream).seek(NS_SEEK_SET, position);
+  // We use `nsIStreamTransportService` service to transform blocking
+  // file input stream into a fully asynchronous stream that can be written
+  // without blocking the main thread.
+  let binaryInputStream = BinaryInputStream(input);
+  let count = length === ALL ? binaryInputStream.available() : length;
+  if (offset === 0) binaryInputStream.readArrayBuffer(count, buffer.buffer);
+  else {
+    let chunk = new Buffer(count);
+    binaryInputStream.readArrayBuffer(count, chunk.buffer);
+    chunk.copy(buffer, offset);
+  }
+
+  return buffer.slice(offset, offset + count);
+};
+exports.readSync = readSync;
+
+/**
+ * Read data from the file specified by `fd`.
+ *
+ * `buffer` is the buffer that the data will be written to.
+ * `offset` is offset within the buffer where writing will start.
+ *
+ * `length` is an integer specifying the number of bytes to read.
+ *
+ * `position` is an integer specifying where to begin reading from in the file.
+ * If `position` is `null`, data will be read from the current file position.
+ *
+ * The callback is given the three arguments, `(error, bytesRead, buffer)`.
+ */
+function read(fd, buffer, offset, length, position, callback) {
+  let bytesRead = 0;
+  let readStream = new ReadStream(fd, { position: position, length: length });
+  readStream.on("data", function onData(data) {
+      data.copy(buffer, offset + bytesRead);
+      bytesRead += data.length;
+  });
+  readStream.on("end", function onEnd() {
+    callback(null, bytesRead, buffer);
+    readStream.destroy();
+  });
+};
+exports.read = read;
+
+/**
+ * Asynchronously reads the entire contents of a file.
+ * The callback is passed two arguments `(error, data)`, where data is the
+ * contents of the file.
+ */
+function readFile(path, encoding, callback) {
+  if (isFunction(encoding)) {
+    callback = encoding
+    encoding = null
+  }
+
+  let buffer = null;
+  try {
+    let readStream = new ReadStream(path);
+    readStream.on("data", function(data) {
+      if (!buffer) buffer = data;
+      else buffer = Buffer.concat([buffer, data], 2);
+    });
+    readStream.on("error", function onError(error) {
+      callback(error);
+    });
+    readStream.on("end", function onEnd() {
+      // Note: Need to destroy before invoking a callback
+      // so that file descriptor is released.
+      readStream.destroy();
+      callback(null, buffer);
+    });
+  }
+  catch (error) {
+    setTimeout(callback, 0, error);
+  }
+};
+exports.readFile = readFile;
+
+/**
+ * Synchronous version of `fs.readFile`. Returns the contents of the path.
+ * If encoding is specified then this function returns a string.
+ * Otherwise it returns a buffer.
+ */
+function readFileSync(path, encoding) {
+  let fd = openSync(path, "r");
+  let size = fstatSync(fd).size;
+  let buffer = new Buffer(size);
+  try {
+    readSync(fd, buffer, 0, ALL, 0);
+  }
+  finally {
+    closeSync(fd);
+  }
+  return buffer;
+};
+exports.readFileSync = readFileSync;
+
+/**
+ * Asynchronously writes data to a file, replacing the file if it already
+ * exists. data can be a string or a buffer.
+ */
+function writeFile(path, content, encoding, callback) {
+  if (!isString(path))
+    throw new TypeError('path must be a string');
+
+  try {
+    if (isFunction(encoding)) {
+      callback = encoding
+      encoding = null
+    }
+    if (isString(content))
+      content = new Buffer(content, encoding);
+
+    let writeStream = new WriteStream(path);
+    let error = null;
+
+    writeStream.end(content, function() {
+      writeStream.destroy();
+      callback(error);
+    });
+
+    writeStream.on("error", function onError(reason) {
+      error = reason;
+      writeStream.destroy();
+    });
+  } catch (error) {
+    callback(error);
+  }
+};
+exports.writeFile = writeFile;
+
+/**
+ * The synchronous version of `fs.writeFile`.
+ */
+function writeFileSync(filename, data, encoding) {
+  // TODO: Implement this in bug 1148209 https://bugzilla.mozilla.org/show_bug.cgi?id=1148209
+  throw Error("Not implemented");
+};
+exports.writeFileSync = writeFileSync;
+
+
+function utimesSync(path, atime, mtime) {
+  throw Error("Not implemented");
+}
+exports.utimesSync = utimesSync;
+
+var utimes = Async(utimesSync);
+exports.utimes = utimes;
+
+function futimesSync(fd, atime, mtime, callback) {
+  throw Error("Not implemented");
+}
+exports.futimesSync = futimesSync;
+
+var futimes = Async(futimesSync);
+exports.futimes = futimes;
+
+function fsyncSync(fd, atime, mtime, callback) {
+  throw Error("Not implemented");
+}
+exports.fsyncSync = fsyncSync;
+
+var fsync = Async(fsyncSync);
+exports.fsync = fsync;
+
+
+/**
+ * Watch for changes on filename. The callback listener will be called each
+ * time the file is accessed.
+ *
+ * The second argument is optional. The options if provided should be an object
+ * containing two members a boolean, persistent, and interval, a polling value
+ * in milliseconds. The default is { persistent: true, interval: 0 }.
+ */
+function watchFile(path, options, listener) {
+  throw Error("Not implemented");
+};
+exports.watchFile = watchFile;
+
+
+function unwatchFile(path, listener) {
+  throw Error("Not implemented");
+}
+exports.unwatchFile = unwatchFile;
+
+function watch(path, options, listener) {
+  throw Error("Not implemented");
+}
+exports.watch = watch;