1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/mozapps/downloads/DownloadPaths.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,89 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +this.EXPORTED_SYMBOLS = [
1.11 + "DownloadPaths",
1.12 +];
1.13 +
1.14 +/**
1.15 + * This module provides the DownloadPaths object which contains methods for
1.16 + * giving names and paths to files being downloaded.
1.17 + *
1.18 + * List of methods:
1.19 + *
1.20 + * nsILocalFile
1.21 + * createNiceUniqueFile(nsILocalFile aLocalFile)
1.22 + *
1.23 + * [string base, string ext]
1.24 + * splitBaseNameAndExtension(string aLeafName)
1.25 + */
1.26 +
1.27 +const Cc = Components.classes;
1.28 +const Ci = Components.interfaces;
1.29 +const Cu = Components.utils;
1.30 +const Cr = Components.results;
1.31 +
1.32 +this.DownloadPaths = {
1.33 + /**
1.34 + * Creates a uniquely-named file starting from the name of the provided file.
1.35 + * If a file with the provided name already exists, the function attempts to
1.36 + * create nice alternatives, like "base(1).ext" (instead of "base-1.ext").
1.37 + *
1.38 + * If a unique name cannot be found, the function throws the XPCOM exception
1.39 + * NS_ERROR_FILE_TOO_BIG. Other exceptions, like NS_ERROR_FILE_ACCESS_DENIED,
1.40 + * can also be expected.
1.41 + *
1.42 + * @param aTemplateFile
1.43 + * nsILocalFile whose leaf name is going to be used as a template. The
1.44 + * provided object is not modified.
1.45 + * @returns A new instance of an nsILocalFile object pointing to the newly
1.46 + * created empty file. On platforms that support permission bits, the
1.47 + * file is created with permissions 644.
1.48 + */
1.49 + createNiceUniqueFile: function DP_createNiceUniqueFile(aTemplateFile) {
1.50 + // Work on a clone of the provided template file object.
1.51 + var curFile = aTemplateFile.clone().QueryInterface(Ci.nsILocalFile);
1.52 + var [base, ext] = DownloadPaths.splitBaseNameAndExtension(curFile.leafName);
1.53 + // Try other file names, for example "base(1).txt" or "base(1).tar.gz",
1.54 + // only if the file name initially set already exists.
1.55 + for (let i = 1; i < 10000 && curFile.exists(); i++) {
1.56 + curFile.leafName = base + "(" + i + ")" + ext;
1.57 + }
1.58 + // At this point we hand off control to createUnique, which will create the
1.59 + // file with the name we chose, if it is valid. If not, createUnique will
1.60 + // attempt to modify it again, for example it will shorten very long names
1.61 + // that can't be created on some platforms, and for which a normal call to
1.62 + // nsIFile.create would result in NS_ERROR_FILE_NOT_FOUND. This can result
1.63 + // very rarely in strange names like "base(9999).tar-1.gz" or "ba-1.gz".
1.64 + curFile.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, 0644);
1.65 + return curFile;
1.66 + },
1.67 +
1.68 + /**
1.69 + * Separates the base name from the extension in a file name, recognizing some
1.70 + * double extensions like ".tar.gz".
1.71 + *
1.72 + * @param aLeafName
1.73 + * The full leaf name to be parsed. Be careful when processing names
1.74 + * containing leading or trailing dots or spaces.
1.75 + * @returns [base, ext]
1.76 + * The base name of the file, which can be empty, and its extension,
1.77 + * which always includes the leading dot unless it's an empty string.
1.78 + * Concatenating the two items always results in the original name.
1.79 + */
1.80 + splitBaseNameAndExtension: function DP_splitBaseNameAndExtension(aLeafName) {
1.81 + // The following regular expression is built from these key parts:
1.82 + // .*? Matches the base name non-greedily.
1.83 + // \.[A-Z0-9]{1,3} Up to three letters or numbers preceding a
1.84 + // double extension.
1.85 + // \.(?:gz|bz2|Z) The second part of common double extensions.
1.86 + // \.[^.]* Matches any extension or a single trailing dot.
1.87 + var [, base, ext] = /(.*?)(\.[A-Z0-9]{1,3}\.(?:gz|bz2|Z)|\.[^.]*)?$/i
1.88 + .exec(aLeafName);
1.89 + // Return an empty string instead of undefined if no extension is found.
1.90 + return [base, ext || ""];
1.91 + }
1.92 +};
