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Diffstat (limited to 'services/sync/modules/addonsreconciler.js')
| -rw-r--r-- | services/sync/modules/addonsreconciler.js | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/services/sync/modules/addonsreconciler.js b/services/sync/modules/addonsreconciler.js new file mode 100644 index 0000000000..c9da4d6f6c --- /dev/null +++ b/services/sync/modules/addonsreconciler.js @@ -0,0 +1,592 @@ +/* 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 file contains middleware to reconcile state of AddonManager for + * purposes of tracking events for Sync. The content in this file exists + * because AddonManager does not have a getChangesSinceX() API and adding + * that functionality properly was deemed too time-consuming at the time + * add-on sync was originally written. If/when AddonManager adds this API, + * this file can go away and the add-ons engine can be rewritten to use it. + * + * It was decided to have this tracking functionality exist in a separate + * standalone file so it could be more easily understood, tested, and + * hopefully ported. + */ + +"use strict"; + +const { Log } = ChromeUtils.import("resource://gre/modules/Log.jsm"); +const { Svc, Utils } = ChromeUtils.import("resource://services-sync/util.js"); +const { AddonManager } = ChromeUtils.import( + "resource://gre/modules/AddonManager.jsm" +); + +const DEFAULT_STATE_FILE = "addonsreconciler"; + +var CHANGE_INSTALLED = 1; +var CHANGE_UNINSTALLED = 2; +var CHANGE_ENABLED = 3; +var CHANGE_DISABLED = 4; + +var EXPORTED_SYMBOLS = [ + "AddonsReconciler", + "CHANGE_INSTALLED", + "CHANGE_UNINSTALLED", + "CHANGE_ENABLED", + "CHANGE_DISABLED", +]; +/** + * Maintains state of add-ons. + * + * State is maintained in 2 data structures, an object mapping add-on IDs + * to metadata and an array of changes over time. The object mapping can be + * thought of as a minimal copy of data from AddonManager which is needed for + * Sync. The array is effectively a log of changes over time. + * + * The data structures are persisted to disk by serializing to a JSON file in + * the current profile. The data structures are updated by 2 mechanisms. First, + * they can be refreshed from the global state of the AddonManager. This is a + * sure-fire way of ensuring the reconciler is up to date. Second, the + * reconciler adds itself as an AddonManager listener. When it receives change + * notifications, it updates its internal state incrementally. + * + * The internal state is persisted to a JSON file in the profile directory. + * + * An instance of this is bound to an AddonsEngine instance. In reality, it + * likely exists as a singleton. To AddonsEngine, it functions as a store and + * an entity which emits events for tracking. + * + * The usage pattern for instances of this class is: + * + * let reconciler = new AddonsReconciler(...); + * await reconciler.ensureStateLoaded(); + * + * // At this point, your instance should be ready to use. + * + * When you are finished with the instance, please call: + * + * reconciler.stopListening(); + * await reconciler.saveState(...); + * + * This class uses the AddonManager AddonListener interface. + * When an add-on is installed, listeners are called in the following order: + * AL.onInstalling, AL.onInstalled + * + * For uninstalls, we see AL.onUninstalling then AL.onUninstalled. + * + * Enabling and disabling work by sending: + * + * AL.onEnabling, AL.onEnabled + * AL.onDisabling, AL.onDisabled + * + * Actions can be undone. All undoable actions notify the same + * AL.onOperationCancelled event. We treat this event like any other. + * + * When an add-on is uninstalled from about:addons, the user is offered an + * "Undo" option, which leads to the following sequence of events as + * observed by an AddonListener: + * Add-ons are first disabled then they are actually uninstalled. So, we will + * see AL.onDisabling and AL.onDisabled. The onUninstalling and onUninstalled + * events only come after the Addon Manager is closed or another view is + * switched to. In the case of Sync performing the uninstall, the uninstall + * events will occur immediately. However, we still see disabling events and + * heed them like they were normal. In the end, the state is proper. + */ +function AddonsReconciler(queueCaller) { + this._log = Log.repository.getLogger("Sync.AddonsReconciler"); + this._log.manageLevelFromPref("services.sync.log.logger.addonsreconciler"); + this.queueCaller = queueCaller; + + Svc.Obs.add("xpcom-shutdown", this.stopListening, this); +} +AddonsReconciler.prototype = { + /** Flag indicating whether we are listening to AddonManager events. */ + _listening: false, + + /** + * Define this as false if the reconciler should not persist state + * to disk when handling events. + * + * This allows test code to avoid spinning to write during observer + * notifications and xpcom shutdown, which appears to cause hangs on WinXP + * (Bug 873861). + */ + _shouldPersist: true, + + /** Log logger instance */ + _log: null, + + /** + * Container for add-on metadata. + * + * Keys are add-on IDs. Values are objects which describe the state of the + * add-on. This is a minimal mirror of data that can be queried from + * AddonManager. In some cases, we retain data longer than AddonManager. + */ + _addons: {}, + + /** + * List of add-on changes over time. + * + * Each element is an array of [time, change, id]. + */ + _changes: [], + + /** + * Objects subscribed to changes made to this instance. + */ + _listeners: [], + + /** + * Accessor for add-ons in this object. + * + * Returns an object mapping add-on IDs to objects containing metadata. + */ + get addons() { + return this._addons; + }, + + async ensureStateLoaded() { + if (!this._promiseStateLoaded) { + this._promiseStateLoaded = this.loadState(); + } + return this._promiseStateLoaded; + }, + + /** + * Load reconciler state from a file. + * + * The path is relative to the weave directory in the profile. If no + * path is given, the default one is used. + * + * If the file does not exist or there was an error parsing the file, the + * state will be transparently defined as empty. + * + * @param file + * Path to load. ".json" is appended automatically. If not defined, + * a default path will be consulted. + */ + async loadState(file = DEFAULT_STATE_FILE) { + let json = await Utils.jsonLoad(file, this); + this._addons = {}; + this._changes = []; + + if (!json) { + this._log.debug("No data seen in loaded file: " + file); + return false; + } + + let version = json.version; + if (!version || version != 1) { + this._log.error( + "Could not load JSON file because version not " + + "supported: " + + version + ); + return false; + } + + this._addons = json.addons; + for (let id in this._addons) { + let record = this._addons[id]; + record.modified = new Date(record.modified); + } + + for (let [time, change, id] of json.changes) { + this._changes.push([new Date(time), change, id]); + } + + return true; + }, + + /** + * Saves the current state to a file in the local profile. + * + * @param file + * String path in profile to save to. If not defined, the default + * will be used. + */ + async saveState(file = DEFAULT_STATE_FILE) { + let state = { version: 1, addons: {}, changes: [] }; + + for (let [id, record] of Object.entries(this._addons)) { + state.addons[id] = {}; + for (let [k, v] of Object.entries(record)) { + if (k == "modified") { + state.addons[id][k] = v.getTime(); + } else { + state.addons[id][k] = v; + } + } + } + + for (let [time, change, id] of this._changes) { + state.changes.push([time.getTime(), change, id]); + } + + this._log.info("Saving reconciler state to file: " + file); + await Utils.jsonSave(file, this, state); + }, + + /** + * Registers a change listener with this instance. + * + * Change listeners are called every time a change is recorded. The listener + * is an object with the function "changeListener" that takes 3 arguments, + * the Date at which the change happened, the type of change (a CHANGE_* + * constant), and the add-on state object reflecting the current state of + * the add-on at the time of the change. + * + * @param listener + * Object containing changeListener function. + */ + addChangeListener: function addChangeListener(listener) { + if (!this._listeners.includes(listener)) { + this._log.debug("Adding change listener."); + this._listeners.push(listener); + } + }, + + /** + * Removes a previously-installed change listener from the instance. + * + * @param listener + * Listener instance to remove. + */ + removeChangeListener: function removeChangeListener(listener) { + this._listeners = this._listeners.filter(element => { + if (element == listener) { + this._log.debug("Removing change listener."); + return false; + } + return true; + }); + }, + + /** + * Tells the instance to start listening for AddonManager changes. + * + * This is typically called automatically when Sync is loaded. + */ + startListening: function startListening() { + if (this._listening) { + return; + } + + this._log.info("Registering as Add-on Manager listener."); + AddonManager.addAddonListener(this); + this._listening = true; + }, + + /** + * Tells the instance to stop listening for AddonManager changes. + * + * The reconciler should always be listening. This should only be called when + * the instance is being destroyed. + * + * This function will get called automatically on XPCOM shutdown. However, it + * is a best practice to call it yourself. + */ + stopListening: function stopListening() { + if (!this._listening) { + return; + } + + this._log.debug("Stopping listening and removing AddonManager listener."); + AddonManager.removeAddonListener(this); + this._listening = false; + }, + + /** + * Refreshes the global state of add-ons by querying the AddonManager. + */ + async refreshGlobalState() { + this._log.info("Refreshing global state from AddonManager."); + + let installs; + let addons = await AddonManager.getAllAddons(); + + let ids = {}; + + for (let addon of addons) { + ids[addon.id] = true; + await this.rectifyStateFromAddon(addon); + } + + // Look for locally-defined add-ons that no longer exist and update their + // record. + for (let [id, addon] of Object.entries(this._addons)) { + if (id in ids) { + continue; + } + + // If the id isn't in ids, it means that the add-on has been deleted or + // the add-on is in the process of being installed. We detect the + // latter by seeing if an AddonInstall is found for this add-on. + + if (!installs) { + installs = await AddonManager.getAllInstalls(); + } + + let installFound = false; + for (let install of installs) { + if ( + install.addon && + install.addon.id == id && + install.state == AddonManager.STATE_INSTALLED + ) { + installFound = true; + break; + } + } + + if (installFound) { + continue; + } + + if (addon.installed) { + addon.installed = false; + this._log.debug( + "Adding change because add-on not present in " + + "Add-on Manager: " + + id + ); + await this._addChange(new Date(), CHANGE_UNINSTALLED, addon); + } + } + + // See note for _shouldPersist. + if (this._shouldPersist) { + await this.saveState(); + } + }, + + /** + * Rectifies the state of an add-on from an Addon instance. + * + * This basically says "given an Addon instance, assume it is truth and + * apply changes to the local state to reflect it." + * + * This function could result in change listeners being called if the local + * state differs from the passed add-on's state. + * + * @param addon + * Addon instance being updated. + */ + async rectifyStateFromAddon(addon) { + this._log.debug( + `Rectifying state for addon ${addon.name} (version=${addon.version}, id=${addon.id})` + ); + + let id = addon.id; + let enabled = !addon.userDisabled; + let guid = addon.syncGUID; + let now = new Date(); + + if (!(id in this._addons)) { + let record = { + id, + guid, + enabled, + installed: true, + modified: now, + type: addon.type, + scope: addon.scope, + foreignInstall: addon.foreignInstall, + isSyncable: addon.isSyncable, + }; + this._addons[id] = record; + this._log.debug( + "Adding change because add-on not present locally: " + id + ); + await this._addChange(now, CHANGE_INSTALLED, record); + return; + } + + let record = this._addons[id]; + record.isSyncable = addon.isSyncable; + + if (!record.installed) { + // It is possible the record is marked as uninstalled because an + // uninstall is pending. + if (!(addon.pendingOperations & AddonManager.PENDING_UNINSTALL)) { + record.installed = true; + record.modified = now; + } + } + + if (record.enabled != enabled) { + record.enabled = enabled; + record.modified = now; + let change = enabled ? CHANGE_ENABLED : CHANGE_DISABLED; + this._log.debug("Adding change because enabled state changed: " + id); + await this._addChange(new Date(), change, record); + } + + if (record.guid != guid) { + record.guid = guid; + // We don't record a change because the Sync engine rectifies this on its + // own. This is tightly coupled with Sync. If this code is ever lifted + // outside of Sync, this exception should likely be removed. + } + }, + + /** + * Record a change in add-on state. + * + * @param date + * Date at which the change occurred. + * @param change + * The type of the change. A CHANGE_* constant. + * @param state + * The new state of the add-on. From this.addons. + */ + async _addChange(date, change, state) { + this._log.info("Change recorded for " + state.id); + this._changes.push([date, change, state.id]); + + for (let listener of this._listeners) { + try { + await listener.changeListener(date, change, state); + } catch (ex) { + this._log.error("Exception calling change listener", ex); + } + } + }, + + /** + * Obtain the set of changes to add-ons since the date passed. + * + * This will return an array of arrays. Each entry in the array has the + * elements [date, change_type, id], where + * + * date - Date instance representing when the change occurred. + * change_type - One of CHANGE_* constants. + * id - ID of add-on that changed. + */ + getChangesSinceDate(date) { + let length = this._changes.length; + for (let i = 0; i < length; i++) { + if (this._changes[i][0] >= date) { + return this._changes.slice(i); + } + } + + return []; + }, + + /** + * Prunes all recorded changes from before the specified Date. + * + * @param date + * Entries older than this Date will be removed. + */ + pruneChangesBeforeDate(date) { + this._changes = this._changes.filter(function test_age(change) { + return change[0] >= date; + }); + }, + + /** + * Obtains the set of all known Sync GUIDs for add-ons. + */ + getAllSyncGUIDs() { + let result = {}; + for (let id in this.addons) { + result[id] = true; + } + + return result; + }, + + /** + * Obtain the add-on state record for an add-on by Sync GUID. + * + * If the add-on could not be found, returns null. + * + * @param guid + * Sync GUID of add-on to retrieve. + */ + getAddonStateFromSyncGUID(guid) { + for (let id in this.addons) { + let addon = this.addons[id]; + if (addon.guid == guid) { + return addon; + } + } + + return null; + }, + + /** + * Handler that is invoked as part of the AddonManager listeners. + */ + async _handleListener(action, addon) { + // Since this is called as an observer, we explicitly trap errors and + // log them to ourselves so we don't see errors reported elsewhere. + try { + let id = addon.id; + this._log.debug("Add-on change: " + action + " to " + id); + + switch (action) { + case "onEnabled": + case "onDisabled": + case "onInstalled": + case "onInstallEnded": + case "onOperationCancelled": + await this.rectifyStateFromAddon(addon); + break; + + case "onUninstalled": + let id = addon.id; + let addons = this.addons; + if (id in addons) { + let now = new Date(); + let record = addons[id]; + record.installed = false; + record.modified = now; + this._log.debug( + "Adding change because of uninstall listener: " + id + ); + await this._addChange(now, CHANGE_UNINSTALLED, record); + } + } + + // See note for _shouldPersist. + if (this._shouldPersist) { + await this.saveState(); + } + } catch (ex) { + this._log.warn("Exception", ex); + } + }, + + // AddonListeners + onEnabled: function onEnabled(addon) { + this.queueCaller.enqueueCall(() => + this._handleListener("onEnabled", addon) + ); + }, + onDisabled: function onDisabled(addon) { + this.queueCaller.enqueueCall(() => + this._handleListener("onDisabled", addon) + ); + }, + onInstalled: function onInstalled(addon) { + this.queueCaller.enqueueCall(() => + this._handleListener("onInstalled", addon) + ); + }, + onUninstalled: function onUninstalled(addon) { + this.queueCaller.enqueueCall(() => + this._handleListener("onUninstalled", addon) + ); + }, + onOperationCancelled: function onOperationCancelled(addon) { + this.queueCaller.enqueueCall(() => + this._handleListener("onOperationCancelled", addon) + ); + }, +}; |