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Diffstat (limited to 'toolkit/modules/FileUtils.jsm')
| -rw-r--r-- | toolkit/modules/FileUtils.jsm | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/toolkit/modules/FileUtils.jsm b/toolkit/modules/FileUtils.jsm new file mode 100644 index 000000000..df17d60a2 --- /dev/null +++ b/toolkit/modules/FileUtils.jsm @@ -0,0 +1,176 @@ +/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */ +/* 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/. */ + +this.EXPORTED_SYMBOLS = [ "FileUtils" ]; + +Components.utils.import("resource://gre/modules/XPCOMUtils.jsm"); + +const Cc = Components.classes; +const Ci = Components.interfaces; +const Cr = Components.results; + +XPCOMUtils.defineLazyServiceGetter(this, "gDirService", + "@mozilla.org/file/directory_service;1", + "nsIProperties"); + +this.FileUtils = { + MODE_RDONLY : 0x01, + MODE_WRONLY : 0x02, + MODE_RDWR : 0x04, + MODE_CREATE : 0x08, + MODE_APPEND : 0x10, + MODE_TRUNCATE : 0x20, + + PERMS_FILE : 0o644, + PERMS_DIRECTORY : 0o755, + + /** + * Gets a file at the specified hierarchy under a nsIDirectoryService key. + * @param key + * The Directory Service Key to start from + * @param pathArray + * An array of path components to locate beneath the directory + * specified by |key|. The last item in this array must be the + * leaf name of a file. + * @return nsIFile object for the file specified. The file is NOT created + * if it does not exist, however all required directories along + * the way are. + */ + getFile: function FileUtils_getFile(key, pathArray, followLinks) { + var file = this.getDir(key, pathArray.slice(0, -1), true, followLinks); + file.append(pathArray[pathArray.length - 1]); + return file; + }, + + /** + * Gets a directory at the specified hierarchy under a nsIDirectoryService + * key. + * @param key + * The Directory Service Key to start from + * @param pathArray + * An array of path components to locate beneath the directory + * specified by |key| + * @param shouldCreate + * true if the directory hierarchy specified in |pathArray| + * should be created if it does not exist, false otherwise. + * @param followLinks (optional) + * true if links should be followed, false otherwise. + * @return nsIFile object for the location specified. + */ + getDir: function FileUtils_getDir(key, pathArray, shouldCreate, followLinks) { + var dir = gDirService.get(key, Ci.nsIFile); + for (var i = 0; i < pathArray.length; ++i) { + dir.append(pathArray[i]); + } + + if (shouldCreate) { + try { + dir.create(Ci.nsIFile.DIRECTORY_TYPE, this.PERMS_DIRECTORY); + } catch (ex) { + if (ex.result != Cr.NS_ERROR_FILE_ALREADY_EXISTS) { + throw ex; + } + // Ignore the exception due to a directory that already exists. + } + } + + if (!followLinks) + dir.followLinks = false; + return dir; + }, + + /** + * Opens a file output stream for writing. + * @param file + * The file to write to. + * @param modeFlags + * (optional) File open flags. Can be undefined. + * @returns nsIFileOutputStream to write to. + * @note The stream is initialized with the DEFER_OPEN behavior flag. + * See nsIFileOutputStream. + */ + openFileOutputStream: function FileUtils_openFileOutputStream(file, modeFlags) { + var fos = Cc["@mozilla.org/network/file-output-stream;1"]. + createInstance(Ci.nsIFileOutputStream); + return this._initFileOutputStream(fos, file, modeFlags); + }, + + /** + * Opens an atomic file output stream for writing. + * @param file + * The file to write to. + * @param modeFlags + * (optional) File open flags. Can be undefined. + * @returns nsIFileOutputStream to write to. + * @note The stream is initialized with the DEFER_OPEN behavior flag. + * See nsIFileOutputStream. + * OpeanAtomicFileOutputStream is generally better than openSafeFileOutputStream + * baecause flushing is not needed in most of the issues. + */ + openAtomicFileOutputStream: function FileUtils_openAtomicFileOutputStream(file, modeFlags) { + var fos = Cc["@mozilla.org/network/atomic-file-output-stream;1"]. + createInstance(Ci.nsIFileOutputStream); + return this._initFileOutputStream(fos, file, modeFlags); + }, + + /** + * Opens a safe file output stream for writing. + * @param file + * The file to write to. + * @param modeFlags + * (optional) File open flags. Can be undefined. + * @returns nsIFileOutputStream to write to. + * @note The stream is initialized with the DEFER_OPEN behavior flag. + * See nsIFileOutputStream. + */ + openSafeFileOutputStream: function FileUtils_openSafeFileOutputStream(file, modeFlags) { + var fos = Cc["@mozilla.org/network/safe-file-output-stream;1"]. + createInstance(Ci.nsIFileOutputStream); + return this._initFileOutputStream(fos, file, modeFlags); + }, + + _initFileOutputStream: function FileUtils__initFileOutputStream(fos, file, modeFlags) { + if (modeFlags === undefined) + modeFlags = this.MODE_WRONLY | this.MODE_CREATE | this.MODE_TRUNCATE; + fos.init(file, modeFlags, this.PERMS_FILE, fos.DEFER_OPEN); + return fos; + }, + + /** + * Closes an atomic file output stream. + * @param stream + * The stream to close. + */ + closeAtomicFileOutputStream: function FileUtils_closeAtomicFileOutputStream(stream) { + if (stream instanceof Ci.nsISafeOutputStream) { + try { + stream.finish(); + return; + } + catch (e) { + } + } + stream.close(); + }, + + /** + * Closes a safe file output stream. + * @param stream + * The stream to close. + */ + closeSafeFileOutputStream: function FileUtils_closeSafeFileOutputStream(stream) { + if (stream instanceof Ci.nsISafeOutputStream) { + try { + stream.finish(); + return; + } + catch (e) { + } + } + stream.close(); + }, + + File: Components.Constructor("@mozilla.org/file/local;1", Ci.nsILocalFile, "initWithPath") +}; |