Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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.
+  }
+}