The Tor Browser / file revision

 /* 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";

 const { Cc, Ci } = require("chrome");

 const system = require("sdk/system");

 const file = require("sdk/io/file");

 const unload = require("sdk/system/unload");

 // Retrieve the path to the OS temporary directory:

 const tmpDir = require("sdk/system").pathFor("TmpD");

 // List of all tmp file created

 let files = [];

 // Remove all tmp files on addon disabling

 unload.when(function () {

   files.forEach(function (path){

     // Catch exception in order to avoid leaking following files

     try {

       if (file.exists(path))

         file.remove(path);

     }

     catch(e) {

       console.exception(e);

     }

   });

 });

 // Utility function that synchronously reads local resource from the given

 // `uri` and returns content string. Read in binary mode.

 function readBinaryURI(uri) {

   let ioservice = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);

   let channel = ioservice.newChannel(uri, "UTF-8", null);

   let stream = Cc["@mozilla.org/binaryinputstream;1"].

                createInstance(Ci.nsIBinaryInputStream);

   stream.setInputStream(channel.open());

   let data = "";

   while (true) {

     let available = stream.available();

     if (available <= 0)

       break;

     data += stream.readBytes(available);

   }

   stream.close();

   return data;

 }

 // Create a temporary file from a given string and returns its path

 exports.createFromString = function createFromString(data, tmpName) {  

   let filename = (tmpName ? tmpName : "tmp-file") + "-" + (new Date().getTime());

   let path = file.join(tmpDir, filename);

   let tmpFile = file.open(path, "wb");

   tmpFile.write(data);

   tmpFile.close();

   // Register tmp file path

   files.push(path);

   return path;

 }

 // Create a temporary file from a given URL and returns its path

 exports.createFromURL = function createFromURL(url, tmpName) {

   let data = readBinaryURI(url);

   return exports.createFromString(data, tmpName);

 }