diff options
Diffstat (limited to 'browser/components/sessionstore/ContentSessionStore.sys.mjs')
| -rw-r--r-- | browser/components/sessionstore/ContentSessionStore.sys.mjs | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/browser/components/sessionstore/ContentSessionStore.sys.mjs b/browser/components/sessionstore/ContentSessionStore.sys.mjs new file mode 100644 index 0000000000..61aa911f0b --- /dev/null +++ b/browser/components/sessionstore/ContentSessionStore.sys.mjs @@ -0,0 +1,686 @@ +/* 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/. */ + +import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs"; +import { + clearTimeout, + setTimeoutWithTarget, +} from "resource://gre/modules/Timer.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + ContentRestore: "resource:///modules/sessionstore/ContentRestore.sys.mjs", + SessionHistory: "resource://gre/modules/sessionstore/SessionHistory.sys.mjs", +}); + +// This pref controls whether or not we send updates to the parent on a timeout +// or not, and should only be used for tests or debugging. +const TIMEOUT_DISABLED_PREF = "browser.sessionstore.debug.no_auto_updates"; + +const PREF_INTERVAL = "browser.sessionstore.interval"; + +const kNoIndex = Number.MAX_SAFE_INTEGER; +const kLastIndex = Number.MAX_SAFE_INTEGER - 1; + +class Handler { + constructor(store) { + this.store = store; + } + + get contentRestore() { + return this.store.contentRestore; + } + + get contentRestoreInitialized() { + return this.store.contentRestoreInitialized; + } + + get mm() { + return this.store.mm; + } + + get messageQueue() { + return this.store.messageQueue; + } +} + +/** + * Listens for and handles content events that we need for the + * session store service to be notified of state changes in content. + */ +class EventListener extends Handler { + constructor(store) { + super(store); + + SessionStoreUtils.addDynamicFrameFilteredListener( + this.mm, + "load", + this, + true + ); + } + + handleEvent(event) { + let { content } = this.mm; + + // Ignore load events from subframes. + if (event.target != content.document) { + return; + } + + if (content.document.documentURI.startsWith("about:reader")) { + if ( + event.type == "load" && + !content.document.body.classList.contains("loaded") + ) { + // Don't restore the scroll position of an about:reader page at this + // point; listen for the custom event dispatched from AboutReader.sys.mjs. + content.addEventListener("AboutReaderContentReady", this); + return; + } + + content.removeEventListener("AboutReaderContentReady", this); + } + + if (this.contentRestoreInitialized) { + // Restore the form data and scroll position. + this.contentRestore.restoreDocument(); + } + } +} + +/** + * Listens for changes to the session history. Whenever the user navigates + * we will collect URLs and everything belonging to session history. + * + * Causes a SessionStore:update message to be sent that contains the current + * session history. + * + * Example: + * {entries: [{url: "about:mozilla", ...}, ...], index: 1} + */ +class SessionHistoryListener extends Handler { + constructor(store) { + super(store); + + this._fromIdx = kNoIndex; + + // By adding the SHistoryListener immediately, we will unfortunately be + // notified of every history entry as the tab is restored. We don't bother + // waiting to add the listener later because these notifications are cheap. + // We will likely only collect once since we are batching collection on + // a delay. + this.mm.docShell + .QueryInterface(Ci.nsIWebNavigation) + .sessionHistory.legacySHistory.addSHistoryListener(this); // OK in non-geckoview + + let webProgress = this.mm.docShell + .QueryInterface(Ci.nsIInterfaceRequestor) + .getInterface(Ci.nsIWebProgress); + + webProgress.addProgressListener( + this, + Ci.nsIWebProgress.NOTIFY_STATE_DOCUMENT + ); + + // Collect data if we start with a non-empty shistory. + if (!lazy.SessionHistory.isEmpty(this.mm.docShell)) { + this.collect(); + // When a tab is detached from the window, for the new window there is a + // new SessionHistoryListener created. Normally it is empty at this point + // but in a test env. the initial about:blank might have a children in which + // case we fire off a history message here with about:blank in it. If we + // don't do it ASAP then there is going to be a browser swap and the parent + // will be all confused by that message. + this.store.messageQueue.send(); + } + + // Listen for page title changes. + this.mm.addEventListener("DOMTitleChanged", this); + } + + get mm() { + return this.store.mm; + } + + uninit() { + let sessionHistory = this.mm.docShell.QueryInterface( + Ci.nsIWebNavigation + ).sessionHistory; + if (sessionHistory) { + sessionHistory.legacySHistory.removeSHistoryListener(this); // OK in non-geckoview + } + } + + collect() { + // We want to send down a historychange even for full collects in case our + // session history is a partial session history, in which case we don't have + // enough information for a full update. collectFrom(-1) tells the collect + // function to collect all data avaliable in this process. + if (this.mm.docShell) { + this.collectFrom(-1); + } + } + + // History can grow relatively big with the nested elements, so if we don't have to, we + // don't want to send the entire history all the time. For a simple optimization + // we keep track of the smallest index from after any change has occured and we just send + // the elements from that index. If something more complicated happens we just clear it + // and send the entire history. We always send the additional info like the current selected + // index (so for going back and forth between history entries we set the index to kLastIndex + // if nothing else changed send an empty array and the additonal info like the selected index) + collectFrom(idx) { + if (this._fromIdx <= idx) { + // If we already know that we need to update history fromn index N we can ignore any changes + // tha happened with an element with index larger than N. + // Note: initially we use kNoIndex which is MAX_SAFE_INTEGER which means we don't ignore anything + // here, and in case of navigation in the history back and forth we use kLastIndex which ignores + // only the subsequent navigations, but not any new elements added. + return; + } + + this._fromIdx = idx; + this.store.messageQueue.push("historychange", () => { + if (this._fromIdx === kNoIndex) { + return null; + } + + let history = lazy.SessionHistory.collect( + this.mm.docShell, + this._fromIdx + ); + this._fromIdx = kNoIndex; + return history; + }); + } + + handleEvent(event) { + this.collect(); + } + + OnHistoryNewEntry(newURI, oldIndex) { + // Collect the current entry as well, to make sure to collect any changes + // that were made to the entry while the document was active. + this.collectFrom(oldIndex == -1 ? oldIndex : oldIndex - 1); + } + + OnHistoryGotoIndex() { + // We ought to collect the previously current entry as well, see bug 1350567. + this.collectFrom(kLastIndex); + } + + OnHistoryPurge() { + this.collect(); + } + + OnHistoryReload() { + this.collect(); + return true; + } + + OnHistoryReplaceEntry() { + this.collect(); + } + + /** + * @see nsIWebProgressListener.onStateChange + */ + onStateChange(webProgress, request, stateFlags, status) { + // Ignore state changes for subframes because we're only interested in the + // top-document starting or stopping its load. + if (!webProgress.isTopLevel || webProgress.DOMWindow != this.mm.content) { + return; + } + + // onStateChange will be fired when loading the initial about:blank URI for + // a browser, which we don't actually care about. This is particularly for + // the case of unrestored background tabs, where the content has not yet + // been restored: we don't want to accidentally send any updates to the + // parent when the about:blank placeholder page has loaded. + if (!this.mm.docShell.hasLoadedNonBlankURI) { + return; + } + + if (stateFlags & Ci.nsIWebProgressListener.STATE_START) { + this.collect(); + } else if (stateFlags & Ci.nsIWebProgressListener.STATE_STOP) { + this.collect(); + } + } +} +SessionHistoryListener.prototype.QueryInterface = ChromeUtils.generateQI([ + "nsIWebProgressListener", + "nsISHistoryListener", + "nsISupportsWeakReference", +]); + +/** + * A message queue that takes collected data and will take care of sending it + * to the chrome process. It allows flushing using synchronous messages and + * takes care of any race conditions that might occur because of that. Changes + * will be batched if they're pushed in quick succession to avoid a message + * flood. + */ +class MessageQueue extends Handler { + constructor(store) { + super(store); + + /** + * A map (string -> lazy fn) holding lazy closures of all queued data + * collection routines. These functions will return data collected from the + * docShell. + */ + this._data = new Map(); + + /** + * The delay (in ms) used to delay sending changes after data has been + * invalidated. + */ + this.BATCH_DELAY_MS = 1000; + + /** + * The minimum idle period (in ms) we need for sending data to chrome process. + */ + this.NEEDED_IDLE_PERIOD_MS = 5; + + /** + * Timeout for waiting an idle period to send data. We will set this from + * the pref "browser.sessionstore.interval". + */ + this._timeoutWaitIdlePeriodMs = null; + + /** + * The current timeout ID, null if there is no queue data. We use timeouts + * to damp a flood of data changes and send lots of changes as one batch. + */ + this._timeout = null; + + /** + * Whether or not sending batched messages on a timer is disabled. This should + * only be used for debugging or testing. If you need to access this value, + * you should probably use the timeoutDisabled getter. + */ + this._timeoutDisabled = false; + + /** + * True if there is already a send pending idle dispatch, set to prevent + * scheduling more than one. If false there may or may not be one scheduled. + */ + this._idleScheduled = false; + + this.timeoutDisabled = Services.prefs.getBoolPref(TIMEOUT_DISABLED_PREF); + this._timeoutWaitIdlePeriodMs = Services.prefs.getIntPref(PREF_INTERVAL); + + Services.prefs.addObserver(TIMEOUT_DISABLED_PREF, this); + Services.prefs.addObserver(PREF_INTERVAL, this); + } + + /** + * True if batched messages are not being fired on a timer. This should only + * ever be true when debugging or during tests. + */ + get timeoutDisabled() { + return this._timeoutDisabled; + } + + /** + * Disables sending batched messages on a timer. Also cancels any pending + * timers. + */ + set timeoutDisabled(val) { + this._timeoutDisabled = val; + + if (val && this._timeout) { + clearTimeout(this._timeout); + this._timeout = null; + } + } + + uninit() { + Services.prefs.removeObserver(TIMEOUT_DISABLED_PREF, this); + Services.prefs.removeObserver(PREF_INTERVAL, this); + this.cleanupTimers(); + } + + /** + * Cleanup pending idle callback and timer. + */ + cleanupTimers() { + this._idleScheduled = false; + if (this._timeout) { + clearTimeout(this._timeout); + this._timeout = null; + } + } + + observe(subject, topic, data) { + if (topic == "nsPref:changed") { + switch (data) { + case TIMEOUT_DISABLED_PREF: + this.timeoutDisabled = Services.prefs.getBoolPref( + TIMEOUT_DISABLED_PREF + ); + break; + case PREF_INTERVAL: + this._timeoutWaitIdlePeriodMs = + Services.prefs.getIntPref(PREF_INTERVAL); + break; + default: + console.error("received unknown message '" + data + "'"); + break; + } + } + } + + /** + * Pushes a given |value| onto the queue. The given |key| represents the type + * of data that is stored and can override data that has been queued before + * but has not been sent to the parent process, yet. + * + * @param key (string) + * A unique identifier specific to the type of data this is passed. + * @param fn (function) + * A function that returns the value that will be sent to the parent + * process. + */ + push(key, fn) { + this._data.set(key, fn); + + if (!this._timeout && !this._timeoutDisabled) { + // Wait a little before sending the message to batch multiple changes. + this._timeout = setTimeoutWithTarget( + () => this.sendWhenIdle(), + this.BATCH_DELAY_MS, + this.mm.tabEventTarget + ); + } + } + + /** + * Sends queued data when the remaining idle time is enough or waiting too + * long; otherwise, request an idle time again. If the |deadline| is not + * given, this function is going to schedule the first request. + * + * @param deadline (object) + * An IdleDeadline object passed by idleDispatch(). + */ + sendWhenIdle(deadline) { + if (!this.mm.content) { + // The frameloader is being torn down. Nothing more to do. + return; + } + + if (deadline) { + if ( + deadline.didTimeout || + deadline.timeRemaining() > this.NEEDED_IDLE_PERIOD_MS + ) { + this.send(); + return; + } + } else if (this._idleScheduled) { + // Bail out if there's a pending run. + return; + } + ChromeUtils.idleDispatch(deadline_ => this.sendWhenIdle(deadline_), { + timeout: this._timeoutWaitIdlePeriodMs, + }); + this._idleScheduled = true; + } + + /** + * Sends queued data to the chrome process. + * + * @param options (object) + * {flushID: 123} to specify that this is a flush + * {isFinal: true} to signal this is the final message sent on unload + */ + send(options = {}) { + // Looks like we have been called off a timeout after the tab has been + // closed. The docShell is gone now and we can just return here as there + // is nothing to do. + if (!this.mm.docShell) { + return; + } + + this.cleanupTimers(); + + let flushID = (options && options.flushID) || 0; + let histID = "FX_SESSION_RESTORE_CONTENT_COLLECT_DATA_MS"; + + let data = {}; + for (let [key, func] of this._data) { + if (key != "isPrivate") { + TelemetryStopwatch.startKeyed(histID, key); + } + + let value = func(); + + if (key != "isPrivate") { + TelemetryStopwatch.finishKeyed(histID, key); + } + + if (value || (key != "storagechange" && key != "historychange")) { + data[key] = value; + } + } + + this._data.clear(); + + try { + // Send all data to the parent process. + this.mm.sendAsyncMessage("SessionStore:update", { + data, + flushID, + isFinal: options.isFinal || false, + epoch: this.store.epoch, + }); + } catch (ex) { + if (ex && ex.result == Cr.NS_ERROR_OUT_OF_MEMORY) { + Services.telemetry + .getHistogramById("FX_SESSION_RESTORE_SEND_UPDATE_CAUSED_OOM") + .add(1); + this.mm.sendAsyncMessage("SessionStore:error"); + } + } + } +} + +/** + * Listens for and handles messages sent by the session store service. + */ +const MESSAGES = [ + "SessionStore:restoreHistory", + "SessionStore:restoreTabContent", + "SessionStore:resetRestore", + "SessionStore:flush", + "SessionStore:prepareForProcessChange", +]; + +export class ContentSessionStore { + constructor(mm) { + if (Services.appinfo.sessionHistoryInParent) { + throw new Error("This frame script should not be loaded for SHIP"); + } + + this.mm = mm; + this.messageQueue = new MessageQueue(this); + + this.epoch = 0; + + this.contentRestoreInitialized = false; + + this.handlers = [ + this.messageQueue, + new EventListener(this), + new SessionHistoryListener(this), + ]; + + XPCOMUtils.defineLazyGetter(this, "contentRestore", () => { + this.contentRestoreInitialized = true; + return new lazy.ContentRestore(mm); + }); + + MESSAGES.forEach(m => mm.addMessageListener(m, this)); + + mm.addEventListener("unload", this); + } + + receiveMessage({ name, data }) { + // The docShell might be gone. Don't process messages, + // that will just lead to errors anyway. + if (!this.mm.docShell) { + return; + } + + // A fresh tab always starts with epoch=0. The parent has the ability to + // override that to signal a new era in this tab's life. This enables it + // to ignore async messages that were already sent but not yet received + // and would otherwise confuse the internal tab state. + if (data && data.epoch && data.epoch != this.epoch) { + this.epoch = data.epoch; + } + + switch (name) { + case "SessionStore:restoreHistory": + this.restoreHistory(data); + break; + case "SessionStore:restoreTabContent": + this.restoreTabContent(data); + break; + case "SessionStore:resetRestore": + this.contentRestore.resetRestore(); + break; + case "SessionStore:flush": + this.flush(data); + break; + case "SessionStore:prepareForProcessChange": + // During normal in-process navigations, the DocShell would take + // care of automatically persisting layout history state to record + // scroll positions on the nsSHEntry. Unfortunately, process switching + // is not a normal navigation, so for now we do this ourselves. This + // is a workaround until session history state finally lives in the + // parent process. + this.mm.docShell.persistLayoutHistoryState(); + break; + default: + console.error("received unknown message '" + name + "'"); + break; + } + } + + // non-SHIP only + restoreHistory(data) { + let { epoch, tabData, loadArguments, isRemotenessUpdate } = data; + + this.contentRestore.restoreHistory(tabData, loadArguments, { + // Note: The callbacks passed here will only be used when a load starts + // that was not initiated by sessionstore itself. This can happen when + // some code calls browser.loadURI() or browser.reload() on a pending + // browser/tab. + + onLoadStarted: () => { + // Notify the parent that the tab is no longer pending. + this.mm.sendAsyncMessage("SessionStore:restoreTabContentStarted", { + epoch, + }); + }, + + onLoadFinished: () => { + // Tell SessionStore.sys.mjs that it may want to restore some more tabs, + // since it restores a max of MAX_CONCURRENT_TAB_RESTORES at a time. + this.mm.sendAsyncMessage("SessionStore:restoreTabContentComplete", { + epoch, + }); + }, + }); + + if (Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_DEFAULT) { + // For non-remote tabs, when restoreHistory finishes, we send a synchronous + // message to SessionStore.sys.mjs so that it can run SSTabRestoring. Users of + // SSTabRestoring seem to get confused if chrome and content are out of + // sync about the state of the restore (particularly regarding + // docShell.currentURI). Using a synchronous message is the easiest way + // to temporarily synchronize them. + // + // For remote tabs, because all nsIWebProgress notifications are sent + // asynchronously using messages, we get the same-order guarantees of the + // message manager, and can use an async message. + this.mm.sendSyncMessage("SessionStore:restoreHistoryComplete", { + epoch, + isRemotenessUpdate, + }); + } else { + this.mm.sendAsyncMessage("SessionStore:restoreHistoryComplete", { + epoch, + isRemotenessUpdate, + }); + } + } + + restoreTabContent({ loadArguments, isRemotenessUpdate, reason }) { + let epoch = this.epoch; + + // We need to pass the value of didStartLoad back to SessionStore.sys.mjs. + let didStartLoad = this.contentRestore.restoreTabContent( + loadArguments, + isRemotenessUpdate, + () => { + // Tell SessionStore.sys.mjs that it may want to restore some more tabs, + // since it restores a max of MAX_CONCURRENT_TAB_RESTORES at a time. + this.mm.sendAsyncMessage("SessionStore:restoreTabContentComplete", { + epoch, + isRemotenessUpdate, + }); + } + ); + + this.mm.sendAsyncMessage("SessionStore:restoreTabContentStarted", { + epoch, + isRemotenessUpdate, + reason, + }); + + if (!didStartLoad) { + // Pretend that the load succeeded so that event handlers fire correctly. + this.mm.sendAsyncMessage("SessionStore:restoreTabContentComplete", { + epoch, + isRemotenessUpdate, + }); + } + } + + flush({ id }) { + // Flush the message queue, send the latest updates. + this.messageQueue.send({ flushID: id }); + } + + handleEvent(event) { + if (event.type == "unload") { + this.onUnload(); + } + } + + onUnload() { + // Upon frameLoader destruction, send a final update message to + // the parent and flush all data currently held in the child. + this.messageQueue.send({ isFinal: true }); + + for (let handler of this.handlers) { + if (handler.uninit) { + handler.uninit(); + } + } + + if (this.contentRestoreInitialized) { + // Remove progress listeners. + this.contentRestore.resetRestore(); + } + + // We don't need to take care of any StateChangeNotifier observers as they + // will die with the content script. The same goes for the privacy transition + // observer that will die with the docShell when the tab is closed. + } +} |