The Tor Browser: comparison toolkit/components/jsdownloads/src/DownloadStore.jsm

--1:000000000000
+:bafdb2516ec9
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 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/. */
+/**
+* Handles serialization of Download objects and persistence into a file, so
+* that the state of downloads can be restored across sessions.
+*
+* The file is stored in JSON format, without indentation.  With indentation
+* applied, the file would look like this:
+*
+* {
+*   "list": [
+*     {
+*       "source": "http://www.example.com/download.txt",
+*       "target": "/home/user/Downloads/download.txt"
+*     },
+*     {
+*       "source": {
+*         "url": "http://www.example.com/download.txt",
+*         "referrer": "http://www.example.com/referrer.html"
+*       },
+*       "target": "/home/user/Downloads/download-2.txt"
+*     }
+*   ]
+* }
+*/
+"use strict";
+this.EXPORTED_SYMBOLS = [
+"DownloadStore",
+];
+////////////////////////////////////////////////////////////////////////////////
+//// Globals
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+const Cr = Components.results;
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Downloads",
+"resource://gre/modules/Downloads.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+"resource://gre/modules/osfile.jsm")
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+"resource://gre/modules/Task.jsm");
+XPCOMUtils.defineLazyGetter(this, "gTextDecoder", function () {
+return new TextDecoder();
+});
+XPCOMUtils.defineLazyGetter(this, "gTextEncoder", function () {
+return new TextEncoder();
+});
+////////////////////////////////////////////////////////////////////////////////
+//// DownloadStore
+/**
+* Handles serialization of Download objects and persistence into a file, so
+* that the state of downloads can be restored across sessions.
+*
+* @param aList
+*        DownloadList object to be populated or serialized.
+* @param aPath
+*        String containing the file path where data should be saved.
+*/
+this.DownloadStore = function (aList, aPath)
+{
+this.list = aList;
+this.path = aPath;
+}
+this.DownloadStore.prototype = {
+/**
+* DownloadList object to be populated or serialized.
+*/
+list: null,
+/**
+* String containing the file path where data should be saved.
+*/
+path: "",
+/**
+* This function is called with a Download object as its first argument, and
+* should return true if the item should be saved.
+*/
+onsaveitem: () => true,
+/**
+* Loads persistent downloads from the file to the list.
+*
+* @return {Promise}
+* @resolves When the operation finished successfully.
+* @rejects JavaScript exception.
+*/
+load: function DS_load()
+{
+return Task.spawn(function task_DS_load() {
+let bytes;
+try {
+bytes = yield OS.File.read(this.path);
+} catch (ex if ex instanceof OS.File.Error && ex.becauseNoSuchFile) {
+// If the file does not exist, there are no downloads to load.
+return;
+}
+let storeData = JSON.parse(gTextDecoder.decode(bytes));
+// Create live downloads based on the static snapshot.
+for (let downloadData of storeData.list) {
+try {
+let download = yield Downloads.createDownload(downloadData);
+try {
+if (!download.succeeded && !download.canceled && !download.error) {
+// Try to restart the download if it was in progress during the
+// previous session.
+download.start();
+} else {
+// If the download was not in progress, try to update the current
+// progress from disk.  This is relevant in case we retained
+// partially downloaded data.
+yield download.refresh();
+}
+} finally {
+// Add the download to the list if we succeeded in creating it,
+// after we have updated its initial state.
+yield this.list.add(download);
+}
+} catch (ex) {
+// If an item is unrecognized, don't prevent others from being loaded.
+Cu.reportError(ex);
+}
+}
+}.bind(this));
+},
+/**
+* Saves persistent downloads from the list to the file.
+*
+* If an error occurs, the previous file is not deleted.
+*
+* @return {Promise}
+* @resolves When the operation finished successfully.
+* @rejects JavaScript exception.
+*/
+save: function DS_save()
+{
+return Task.spawn(function task_DS_save() {
+let downloads = yield this.list.getAll();
+// Take a static snapshot of the current state of all the downloads.
+let storeData = { list: [] };
+let atLeastOneDownload = false;
+for (let download of downloads) {
+try {
+if (!this.onsaveitem(download)) {
+continue;
+}
+storeData.list.push(download.toSerializable());
+atLeastOneDownload = true;
+} catch (ex) {
+// If an item cannot be converted to a serializable form, don't
+// prevent others from being saved.
+Cu.reportError(ex);
+}
+}
+if (atLeastOneDownload) {
+// Create or overwrite the file if there are downloads to save.
+let bytes = gTextEncoder.encode(JSON.stringify(storeData));
+yield OS.File.writeAtomic(this.path, bytes,
+{ tmpPath: this.path + ".tmp" });
+} else {
+// Remove the file if there are no downloads to save at all.
+try {
+yield OS.File.remove(this.path);
+} catch (ex if ex instanceof OS.File.Error &&
+(ex.becauseNoSuchFile || ex.becauseAccessDenied)) {
+// On Windows, we may get an access denied error instead of a no such
+// file error if the file existed before, and was recently deleted.
+}
+}
+}.bind(this));
+},
+};

The Tor Browser / file comparison

comparison: toolkit/components/jsdownloads/src/DownloadStore.jsm

toolkit/components/jsdownloads/src/DownloadStore.jsm