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/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
/* 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 = [
"DownloadPaths",
];
/**
* This module provides the DownloadPaths object which contains methods for
* giving names and paths to files being downloaded.
*
* List of methods:
*
* nsILocalFile
* createNiceUniqueFile(nsILocalFile aLocalFile)
*
* [string base, string ext]
* splitBaseNameAndExtension(string aLeafName)
*/
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
const Cr = Components.results;
this.DownloadPaths = {
/**
* Creates a uniquely-named file starting from the name of the provided file.
* If a file with the provided name already exists, the function attempts to
* create nice alternatives, like "base(1).ext" (instead of "base-1.ext").
*
* If a unique name cannot be found, the function throws the XPCOM exception
* NS_ERROR_FILE_TOO_BIG. Other exceptions, like NS_ERROR_FILE_ACCESS_DENIED,
* can also be expected.
*
* @param aTemplateFile
* nsILocalFile whose leaf name is going to be used as a template. The
* provided object is not modified.
* @returns A new instance of an nsILocalFile object pointing to the newly
* created empty file. On platforms that support permission bits, the
* file is created with permissions 644.
*/
createNiceUniqueFile: function DP_createNiceUniqueFile(aTemplateFile) {
// Work on a clone of the provided template file object.
var curFile = aTemplateFile.clone().QueryInterface(Ci.nsILocalFile);
var [base, ext] = DownloadPaths.splitBaseNameAndExtension(curFile.leafName);
// Try other file names, for example "base(1).txt" or "base(1).tar.gz",
// only if the file name initially set already exists.
for (let i = 1; i < 10000 && curFile.exists(); i++) {
curFile.leafName = base + "(" + i + ")" + ext;
}
// At this point we hand off control to createUnique, which will create the
// file with the name we chose, if it is valid. If not, createUnique will
// attempt to modify it again, for example it will shorten very long names
// that can't be created on some platforms, and for which a normal call to
// nsIFile.create would result in NS_ERROR_FILE_NOT_FOUND. This can result
// very rarely in strange names like "base(9999).tar-1.gz" or "ba-1.gz".
curFile.createUnique(Ci.nsIFile.NORMAL_FILE_TYPE, 0o644);
return curFile;
},
/**
* Separates the base name from the extension in a file name, recognizing some
* double extensions like ".tar.gz".
*
* @param aLeafName
* The full leaf name to be parsed. Be careful when processing names
* containing leading or trailing dots or spaces.
* @returns [base, ext]
* The base name of the file, which can be empty, and its extension,
* which always includes the leading dot unless it's an empty string.
* Concatenating the two items always results in the original name.
*/
splitBaseNameAndExtension: function DP_splitBaseNameAndExtension(aLeafName) {
// The following regular expression is built from these key parts:
// .*? Matches the base name non-greedily.
// \.[A-Z0-9]{1,3} Up to three letters or numbers preceding a
// double extension.
// \.(?:gz|bz2|Z) The second part of common double extensions.
// \.[^.]* Matches any extension or a single trailing dot.
var [, base, ext] = /(.*?)(\.[A-Z0-9]{1,3}\.(?:gz|bz2|Z)|\.[^.]*)?$/i
.exec(aLeafName);
// Return an empty string instead of undefined if no extension is found.
return [base, ext || ""];
}
};
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