michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * Code shared by OS.File front-ends.
michael@0:  *
michael@0:  * This code is meant to be included by another library. It is also meant to
michael@0:  * be executed only on a worker thread.
michael@0:  */
michael@0: 
michael@0: if (typeof Components != "undefined") {
michael@0:   throw new Error("osfile_shared_front.jsm cannot be used from the main thread");
michael@0: }
michael@0: (function(exports) {
michael@0: 
michael@0: let SharedAll =
michael@0:   require("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
michael@0: let Path = require("resource://gre/modules/osfile/ospath.jsm");
michael@0: let Lz4 =
michael@0:   require("resource://gre/modules/workers/lz4.js");
michael@0: let LOG = SharedAll.LOG.bind(SharedAll, "Shared front-end");
michael@0: let clone = SharedAll.clone;
michael@0: 
michael@0: /**
michael@0:  * Code shared by implementations of File.
michael@0:  *
michael@0:  * @param {*} fd An OS-specific file handle.
michael@0:  * @param {string} path File path of the file handle, used for error-reporting.
michael@0:  * @constructor
michael@0:  */
michael@0: let AbstractFile = function AbstractFile(fd, path) {
michael@0:   this._fd = fd;
michael@0:   if (!path) {
michael@0:     throw new TypeError("path is expected");
michael@0:   }
michael@0:   this._path = path;
michael@0: };
michael@0: 
michael@0: AbstractFile.prototype = {
michael@0:   /**
michael@0:    * Return the file handle.
michael@0:    *
michael@0:    * @throw OS.File.Error if the file has been closed.
michael@0:    */
michael@0:   get fd() {
michael@0:     if (this._fd) {
michael@0:       return this._fd;
michael@0:     }
michael@0:     throw OS.File.Error.closed("accessing file", this._path);
michael@0:   },
michael@0:   /**
michael@0:    * Read bytes from this file to a new buffer.
michael@0:    *
michael@0:    * @param {number=} bytes If unspecified, read all the remaining bytes from
michael@0:    * this file. If specified, read |bytes| bytes, or less if the file does notclone
michael@0:    * contain that many bytes.
michael@0:    * @param {JSON} options
michael@0:    * @return {Uint8Array} An array containing the bytes read.
michael@0:    */
michael@0:   read: function read(bytes, options = {}) {
michael@0:     options = clone(options);
michael@0:     options.bytes = bytes == null ? this.stat().size : bytes;
michael@0:     let buffer = new Uint8Array(options.bytes);
michael@0:     let size = this.readTo(buffer, options);
michael@0:     if (size == options.bytes) {
michael@0:       return buffer;
michael@0:     } else {
michael@0:       return buffer.subarray(0, size);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Read bytes from this file to an existing buffer.
michael@0:    *
michael@0:    * Note that, by default, this function may perform several I/O
michael@0:    * operations to ensure that the buffer is as full as possible.
michael@0:    *
michael@0:    * @param {Typed Array | C pointer} buffer The buffer in which to
michael@0:    * store the bytes. The buffer must be large enough to
michael@0:    * accomodate |bytes| bytes.
michael@0:    * @param {*=} options Optionally, an object that may contain the
michael@0:    * following fields:
michael@0:    * - {number} bytes The number of |bytes| to write from the buffer. If
michael@0:    * unspecified, this is |buffer.byteLength|. Note that |bytes| is required
michael@0:    * if |buffer| is a C pointer.
michael@0:    *
michael@0:    * @return {number} The number of bytes actually read, which may be
michael@0:    * less than |bytes| if the file did not contain that many bytes left.
michael@0:    */
michael@0:   readTo: function readTo(buffer, options = {}) {
michael@0:     let {ptr, bytes} = SharedAll.normalizeToPointer(buffer, options.bytes);
michael@0:     let pos = 0;
michael@0:     while (pos < bytes) {
michael@0:       let chunkSize = this._read(ptr, bytes - pos, options);
michael@0:       if (chunkSize == 0) {
michael@0:         break;
michael@0:       }
michael@0:       pos += chunkSize;
michael@0:       ptr = SharedAll.offsetBy(ptr, chunkSize);
michael@0:     }
michael@0: 
michael@0:     return pos;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Write bytes from a buffer to this file.
michael@0:    *
michael@0:    * Note that, by default, this function may perform several I/O
michael@0:    * operations to ensure that the buffer is fully written.
michael@0:    *
michael@0:    * @param {Typed array | C pointer} buffer The buffer in which the
michael@0:    * the bytes are stored. The buffer must be large enough to
michael@0:    * accomodate |bytes| bytes.
michael@0:    * @param {*=} options Optionally, an object that may contain the
michael@0:    * following fields:
michael@0:    * - {number} bytes The number of |bytes| to write from the buffer. If
michael@0:    * unspecified, this is |buffer.byteLength|. Note that |bytes| is required
michael@0:    * if |buffer| is a C pointer.
michael@0:    *
michael@0:    * @return {number} The number of bytes actually written.
michael@0:    */
michael@0:   write: function write(buffer, options = {}) {
michael@0: 
michael@0:     let {ptr, bytes} =
michael@0:       SharedAll.normalizeToPointer(buffer, options.bytes || undefined);
michael@0: 
michael@0:     let pos = 0;
michael@0:     while (pos < bytes) {
michael@0:       let chunkSize = this._write(ptr, bytes - pos, options);
michael@0:       pos += chunkSize;
michael@0:       ptr = SharedAll.offsetBy(ptr, chunkSize);
michael@0:     }
michael@0:     return pos;
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Creates and opens a file with a unique name. By default, generate a random HEX number and use it to create a unique new file name.
michael@0:  *
michael@0:  * @param {string} path The path to the file.
michael@0:  * @param {*=} options Additional options for file opening. This
michael@0:  * implementation interprets the following fields:
michael@0:  *
michael@0:  * - {number} humanReadable If |true|, create a new filename appending a decimal number. ie: filename-1.ext, filename-2.ext.
michael@0:  *  If |false| use HEX numbers ie: filename-A65BC0.ext
michael@0:  * - {number} maxReadableNumber Used to limit the amount of tries after a failed
michael@0:  *  file creation. Default is 20.
michael@0:  *
michael@0:  * @return {Object} contains A file object{file} and the path{path}.
michael@0:  * @throws {OS.File.Error} If the file could not be opened.
michael@0:  */
michael@0: AbstractFile.openUnique = function openUnique(path, options = {}) {
michael@0:   let mode = {
michael@0:     create : true
michael@0:   };
michael@0: 
michael@0:   let dirName = Path.dirname(path);
michael@0:   let leafName = Path.basename(path);
michael@0:   let lastDotCharacter = leafName.lastIndexOf('.');
michael@0:   let fileName = leafName.substring(0, lastDotCharacter != -1 ? lastDotCharacter : leafName.length);
michael@0:   let suffix = (lastDotCharacter != -1 ? leafName.substring(lastDotCharacter) : "");
michael@0:   let uniquePath = "";
michael@0:   let maxAttempts = options.maxAttempts || 99;
michael@0:   let humanReadable = !!options.humanReadable;
michael@0:   const HEX_RADIX = 16;
michael@0:   // We produce HEX numbers between 0 and 2^24 - 1.
michael@0:   const MAX_HEX_NUMBER = 16777215;
michael@0: 
michael@0:   try {
michael@0:     return {
michael@0:       path: path,
michael@0:       file: OS.File.open(path, mode)
michael@0:     };
michael@0:   } catch (ex if ex instanceof OS.File.Error && ex.becauseExists) {
michael@0:     for (let i = 0; i < maxAttempts; ++i) {
michael@0:       try {
michael@0:         if (humanReadable) {
michael@0:           uniquePath = Path.join(dirName, fileName + "-" + (i + 1) + suffix);
michael@0:         } else {
michael@0:           let hexNumber = Math.floor(Math.random() * MAX_HEX_NUMBER).toString(HEX_RADIX);
michael@0:           uniquePath = Path.join(dirName, fileName + "-" + hexNumber + suffix);
michael@0:         }
michael@0:         return {
michael@0:           path: uniquePath,
michael@0:           file: OS.File.open(uniquePath, mode)
michael@0:         };
michael@0:       } catch (ex if ex instanceof OS.File.Error && ex.becauseExists) {
michael@0:         // keep trying ...
michael@0:       }
michael@0:     }
michael@0:     throw OS.File.Error.exists("could not find an unused file name.", path);
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Code shared by iterators.
michael@0:  */
michael@0: AbstractFile.AbstractIterator = function AbstractIterator() {
michael@0: };
michael@0: AbstractFile.AbstractIterator.prototype = {
michael@0:   /**
michael@0:    * Allow iterating with |for|
michael@0:    */
michael@0:   __iterator__: function __iterator__() {
michael@0:     return this;
michael@0:   },
michael@0:   /**
michael@0:    * Apply a function to all elements of the directory sequentially.
michael@0:    *
michael@0:    * @param {Function} cb This function will be applied to all entries
michael@0:    * of the directory. It receives as arguments
michael@0:    *  - the OS.File.Entry corresponding to the entry;
michael@0:    *  - the index of the entry in the enumeration;
michael@0:    *  - the iterator itself - calling |close| on the iterator stops
michael@0:    *   the loop.
michael@0:    */
michael@0:   forEach: function forEach(cb) {
michael@0:     let index = 0;
michael@0:     for (let entry in this) {
michael@0:       cb(entry, index++, this);
michael@0:     }
michael@0:   },
michael@0:   /**
michael@0:    * Return several entries at once.
michael@0:    *
michael@0:    * Entries are returned in the same order as a walk with |forEach| or
michael@0:    * |for(...)|.
michael@0:    *
michael@0:    * @param {number=} length If specified, the number of entries
michael@0:    * to return. If unspecified, return all remaining entries.
michael@0:    * @return {Array} An array containing the next |length| entries, or
michael@0:    * less if the iteration contains less than |length| entries left.
michael@0:    */
michael@0:   nextBatch: function nextBatch(length) {
michael@0:     let array = [];
michael@0:     let i = 0;
michael@0:     for (let entry in this) {
michael@0:       array.push(entry);
michael@0:       if (++i >= length) {
michael@0:         return array;
michael@0:       }
michael@0:     }
michael@0:     return array;
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Utility function shared by implementations of |OS.File.open|:
michael@0:  * extract read/write/trunc/create/existing flags from a |mode|
michael@0:  * object.
michael@0:  *
michael@0:  * @param {*=} mode An object that may contain fields |read|,
michael@0:  * |write|, |truncate|, |create|, |existing|. These fields
michael@0:  * are interpreted only if true-ish.
michael@0:  * @return {{read:bool, write:bool, trunc:bool, create:bool,
michael@0:  * existing:bool}} an object recapitulating the options set
michael@0:  * by |mode|.
michael@0:  * @throws {TypeError} If |mode| contains other fields, or
michael@0:  * if it contains both |create| and |truncate|, or |create|
michael@0:  * and |existing|.
michael@0:  */
michael@0: AbstractFile.normalizeOpenMode = function normalizeOpenMode(mode) {
michael@0:   let result = {
michael@0:     read: false,
michael@0:     write: false,
michael@0:     trunc: false,
michael@0:     create: false,
michael@0:     existing: false,
michael@0:     append: true
michael@0:   };
michael@0:   for (let key in mode) {
michael@0:     let val = !!mode[key]; // bool cast.
michael@0:     switch (key) {
michael@0:     case "read":
michael@0:       result.read = val;
michael@0:       break;
michael@0:     case "write":
michael@0:       result.write = val;
michael@0:       break;
michael@0:     case "truncate": // fallthrough
michael@0:     case "trunc":
michael@0:       result.trunc = val;
michael@0:       result.write |= val;
michael@0:       break;
michael@0:     case "create":
michael@0:       result.create = val;
michael@0:       result.write |= val;
michael@0:       break;
michael@0:     case "existing": // fallthrough
michael@0:     case "exist":
michael@0:       result.existing = val;
michael@0:       break;
michael@0:     case "append":
michael@0:       result.append = val;
michael@0:       break;
michael@0:     default:
michael@0:       throw new TypeError("Mode " + key + " not understood");
michael@0:     }
michael@0:   }
michael@0:   // Reject opposite modes
michael@0:   if (result.existing && result.create) {
michael@0:     throw new TypeError("Cannot specify both existing:true and create:true");
michael@0:   }
michael@0:   if (result.trunc && result.create) {
michael@0:     throw new TypeError("Cannot specify both trunc:true and create:true");
michael@0:   }
michael@0:   // Handle read/write
michael@0:   if (!result.write) {
michael@0:     result.read = true;
michael@0:   }
michael@0:   return result;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Return the contents of a file.
michael@0:  *
michael@0:  * @param {string} path The path to the file.
michael@0:  * @param {number=} bytes Optionally, an upper bound to the number of bytes
michael@0:  * to read. DEPRECATED - please use options.bytes instead.
michael@0:  * @param {object=} options Optionally, an object with some of the following
michael@0:  * fields:
michael@0:  * - {number} bytes An upper bound to the number of bytes to read.
michael@0:  * - {string} compression If "lz4" and if the file is compressed using the lz4
michael@0:  *   compression algorithm, decompress the file contents on the fly.
michael@0:  *
michael@0:  * @return {Uint8Array} A buffer holding the bytes
michael@0:  * and the number of bytes read from the file.
michael@0:  */
michael@0: AbstractFile.read = function read(path, bytes, options = {}) {
michael@0:   if (bytes && typeof bytes == "object") {
michael@0:     options = bytes;
michael@0:     bytes = options.bytes || null;
michael@0:   }
michael@0:   if ("encoding" in options && typeof options.encoding != "string") {
michael@0:     throw new TypeError("Invalid type for option encoding");
michael@0:   }
michael@0:   if ("compression" in options && typeof options.compression != "string") {
michael@0:     throw new TypeError("Invalid type for option compression: " + options.compression);
michael@0:   }
michael@0:   if ("bytes" in options && typeof options.bytes != "number") {
michael@0:     throw new TypeError("Invalid type for option bytes");
michael@0:   }
michael@0:   let file = exports.OS.File.open(path);
michael@0:   try {
michael@0:     let buffer = file.read(bytes, options);
michael@0:     if ("compression" in options) {
michael@0:       if (options.compression == "lz4") {
michael@0:         buffer = Lz4.decompressFileContent(buffer, options);
michael@0:       } else {
michael@0:         throw OS.File.Error.invalidArgument("Compression");
michael@0:       }
michael@0:     }
michael@0:     if (!("encoding" in options)) {
michael@0:       return buffer;
michael@0:     }
michael@0:     let decoder;
michael@0:     try {
michael@0:       decoder = new TextDecoder(options.encoding);
michael@0:     } catch (ex if ex instanceof TypeError) {
michael@0:       throw OS.File.Error.invalidArgument("Decode");
michael@0:     }
michael@0:     return decoder.decode(buffer);
michael@0:   } finally {
michael@0:     file.close();
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Write a file, atomically.
michael@0:  *
michael@0:  * By opposition to a regular |write|, this operation ensures that,
michael@0:  * until the contents are fully written, the destination file is
michael@0:  * not modified.
michael@0:  *
michael@0:  * Limitation: In a few extreme cases (hardware failure during the
michael@0:  * write, user unplugging disk during the write, etc.), data may be
michael@0:  * corrupted. If your data is user-critical (e.g. preferences,
michael@0:  * application data, etc.), you may wish to consider adding options
michael@0:  * |tmpPath| and/or |flush| to reduce the likelihood of corruption, as
michael@0:  * detailed below. Note that no combination of options can be
michael@0:  * guaranteed to totally eliminate the risk of corruption.
michael@0:  *
michael@0:  * @param {string} path The path of the file to modify.
michael@0:  * @param {Typed Array | C pointer} buffer A buffer containing the bytes to write.
michael@0:  * @param {*=} options Optionally, an object determining the behavior
michael@0:  * of this function. This object may contain the following fields:
michael@0:  * - {number} bytes The number of bytes to write. If unspecified,
michael@0:  * |buffer.byteLength|. Required if |buffer| is a C pointer.
michael@0:  * - {string} tmpPath If |null| or unspecified, write all data directly
michael@0:  * to |path|. If specified, write all data to a temporary file called
michael@0:  * |tmpPath| and, once this write is complete, rename the file to
michael@0:  * replace |path|. Performing this additional operation is a little
michael@0:  * slower but also a little safer.
michael@0:  * - {bool} noOverwrite - If set, this function will fail if a file already
michael@0:  * exists at |path|.
michael@0:  * - {bool} flush - If |false| or unspecified, return immediately once the
michael@0:  * write is complete. If |true|, before writing, force the operating system
michael@0:  * to write its internal disk buffers to the disk. This is considerably slower
michael@0:  * (not just for the application but for the whole system) but also safer:
michael@0:  * if the system shuts down improperly (typically due to a kernel freeze
michael@0:  * or a power failure) or if the device is disconnected before the buffer
michael@0:  * is flushed, the file has more chances of not being corrupted.
michael@0:  * - {string} compression - If empty or unspecified, do not compress the file.
michael@0:  * If "lz4", compress the contents of the file atomically using lz4. For the
michael@0:  * time being, the container format is specific to Mozilla and cannot be read
michael@0:  * by means other than OS.File.read(..., { compression: "lz4"})
michael@0:  * - {string} backupTo - If specified, backup the destination file as |backupTo|.
michael@0:  * Note that this function renames the destination file before overwriting it.
michael@0:  * If the process or the operating system freezes or crashes
michael@0:  * during the short window between these operations,
michael@0:  * the destination file will have been moved to its backup.
michael@0:  *
michael@0:  * @return {number} The number of bytes actually written.
michael@0:  */
michael@0: AbstractFile.writeAtomic =
michael@0:      function writeAtomic(path, buffer, options = {}) {
michael@0: 
michael@0:   // Verify that path is defined and of the correct type
michael@0:   if (typeof path != "string" || path == "") {
michael@0:     throw new TypeError("File path should be a (non-empty) string");
michael@0:   }
michael@0:   let noOverwrite = options.noOverwrite;
michael@0:   if (noOverwrite && OS.File.exists(path)) {
michael@0:     throw OS.File.Error.exists("writeAtomic", path);
michael@0:   }
michael@0: 
michael@0:   if (typeof buffer == "string") {
michael@0:     // Normalize buffer to a C buffer by encoding it
michael@0:     let encoding = options.encoding || "utf-8";
michael@0:     buffer = new TextEncoder(encoding).encode(buffer);
michael@0:   }
michael@0: 
michael@0:   if ("compression" in options && options.compression == "lz4") {
michael@0:     buffer = Lz4.compressFileContent(buffer, options);
michael@0:     options = Object.create(options);
michael@0:     options.bytes = buffer.byteLength;
michael@0:   }
michael@0: 
michael@0:   let bytesWritten = 0;
michael@0: 
michael@0:   if (!options.tmpPath) {
michael@0:     if (options.backupTo) {
michael@0:       try {
michael@0:         OS.File.move(path, options.backupTo, {noCopy: true});
michael@0:       } catch (ex if ex.becauseNoSuchFile) {
michael@0:         // The file doesn't exist, nothing to backup.
michael@0:       }
michael@0:     }
michael@0:     // Just write, without any renaming trick
michael@0:     let dest = OS.File.open(path, {write: true, truncate: true});
michael@0:     try {
michael@0:       bytesWritten = dest.write(buffer, options);
michael@0:       if (options.flush) {
michael@0:         dest.flush();
michael@0:       }
michael@0:     } finally {
michael@0:       dest.close();
michael@0:     }
michael@0:     return bytesWritten;
michael@0:   }
michael@0: 
michael@0:   let tmpFile = OS.File.open(options.tmpPath, {write: true, truncate: true});
michael@0:   try {
michael@0:     bytesWritten = tmpFile.write(buffer, options);
michael@0:     if (options.flush) {
michael@0:       tmpFile.flush();
michael@0:     }
michael@0:   } catch (x) {
michael@0:     OS.File.remove(options.tmpPath);
michael@0:     throw x;
michael@0:   } finally {
michael@0:     tmpFile.close();
michael@0:   }
michael@0: 
michael@0:   if (options.backupTo) {
michael@0:     try {
michael@0:       OS.File.move(path, options.backupTo, {noCopy: true});
michael@0:     } catch (ex if ex.becauseNoSuchFile) {
michael@0:       // The file doesn't exist, nothing to backup.
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   OS.File.move(options.tmpPath, path, {noCopy: true});
michael@0:   return bytesWritten;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * This function is used by removeDir to avoid calling lstat for each
michael@0:  * files under the specified directory. External callers should not call
michael@0:  * this function directly.
michael@0:  */
michael@0: AbstractFile.removeRecursive = function(path, options = {}) {
michael@0:   let iterator = new OS.File.DirectoryIterator(path);
michael@0:   if (!iterator.exists()) {
michael@0:     if (!("ignoreAbsent" in options) || options.ignoreAbsent) {
michael@0:       return;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   try {
michael@0:     for (let entry in iterator) {
michael@0:       if (entry.isDir) {
michael@0:         if (entry.isLink) {
michael@0:           // Unlike Unix symlinks, NTFS junctions or NTFS symlinks to
michael@0:           // directories are directories themselves. OS.File.remove()
michael@0:           // will not work for them.
michael@0:           OS.File.removeEmptyDir(entry.path, options);
michael@0:         } else {
michael@0:           // Normal directories.
michael@0:           AbstractFile.removeRecursive(entry.path, options);
michael@0:         }
michael@0:       } else {
michael@0:         // NTFS symlinks to files, Unix symlinks, or regular files.
michael@0:         OS.File.remove(entry.path, options);
michael@0:       }
michael@0:     }
michael@0:   } finally {
michael@0:     iterator.close();
michael@0:   }
michael@0: 
michael@0:   OS.File.removeEmptyDir(path);
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Create a directory and, optionally, its parent directories.
michael@0:  *
michael@0:  * @param {string} path The name of the directory.
michael@0:  * @param {*=} options Additional options.
michael@0:  *
michael@0:  * - {string} from If specified, the call to |makeDir| creates all the
michael@0:  * ancestors of |path| that are descendants of |from|. Note that |path|
michael@0:  * must be a descendant of |from|, and that |from| and its existing
michael@0:  * subdirectories present in |path|  must be user-writeable.
michael@0:  * Example:
michael@0:  *   makeDir(Path.join(profileDir, "foo", "bar"), { from: profileDir });
michael@0:  *  creates directories profileDir/foo, profileDir/foo/bar
michael@0:  * - {bool} ignoreExisting If |false|, throw an error if the directory
michael@0:  * already exists. |true| by default. Ignored if |from| is specified.
michael@0:  * - {number} unixMode Under Unix, if specified, a file creation mode,
michael@0:  * as per libc function |mkdir|. If unspecified, dirs are
michael@0:  * created with a default mode of 0700 (dir is private to
michael@0:  * the user, the user can read, write and execute). Ignored under Windows
michael@0:  * or if the file system does not support file creation modes.
michael@0:  * - {C pointer} winSecurity Under Windows, if specified, security
michael@0:  * attributes as per winapi function |CreateDirectory|. If
michael@0:  * unspecified, use the default security descriptor, inherited from
michael@0:  * the parent directory. Ignored under Unix or if the file system
michael@0:  * does not support security descriptors.
michael@0:  */
michael@0: AbstractFile.makeDir = function(path, options = {}) {
michael@0:   if (!options.from) {
michael@0:     return OS.File._makeDir(path, options);
michael@0:   }
michael@0:   if (!path.startsWith(options.from)) {
michael@0:     throw new Error("Incorrect use of option |from|: " + path + " is not a descendant of " + options.from);
michael@0:   }
michael@0:   let innerOptions = Object.create(options, {
michael@0:     ignoreExisting: {
michael@0:       value: true
michael@0:     }
michael@0:   });
michael@0:   // Compute the elements that appear in |path| but not in |options.from|.
michael@0:   let items = Path.split(path).components.slice(Path.split(options.from).components.length);
michael@0:   let current = options.from;
michael@0:   for (let item of items) {
michael@0:     current = Path.join(current, item);
michael@0:     OS.File._makeDir(current, innerOptions);
michael@0:   }
michael@0: };
michael@0: 
michael@0: if (!exports.OS.Shared) {
michael@0:   exports.OS.Shared = {};
michael@0: }
michael@0: exports.OS.Shared.AbstractFile = AbstractFile;
michael@0: })(this);