Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 681 insertions, 0 deletions

diff --git a/browser/components/pagedata/PageDataService.sys.mjs b/browser/components/pagedata/PageDataService.sys.mjs
new file mode 100644
index 0000000000..5a3c67ee0b
--- /dev/null
+++ b/browser/components/pagedata/PageDataService.sys.mjs
@@ -0,0 +1,681 @@
+/* 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 { EventEmitter } from "resource://gre/modules/EventEmitter.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  E10SUtils: "resource://gre/modules/E10SUtils.sys.mjs",
+  HiddenFrame: "resource://gre/modules/HiddenFrame.sys.mjs",
+  PromiseUtils: "resource://gre/modules/PromiseUtils.sys.mjs",
+});
+
+XPCOMUtils.defineLazyModuleGetters(lazy, {
+  BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "logConsole", function () {
+  return console.createInstance({
+    prefix: "PageData",
+    maxLogLevel: Services.prefs.getBoolPref("browser.pagedata.log", false)
+      ? "Debug"
+      : "Warn",
+  });
+});
+
+XPCOMUtils.defineLazyServiceGetters(lazy, {
+  idleService: ["@mozilla.org/widget/useridleservice;1", "nsIUserIdleService"],
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "fetchIdleTime",
+  "browser.pagedata.fetchIdleTime",
+  300
+);
+
+const ALLOWED_SCHEMES = ["http", "https", "data", "blob"];
+
+const BACKGROUND_WIDTH = 1024;
+const BACKGROUND_HEIGHT = 768;
+
+/**
+ * Shifts the first element out of the set.
+ *
+ * @param {Set<T>} set
+ *   The set containing elements.
+ * @returns {T | undefined} The first element in the set or undefined if
+ *   there is nothing in the set.
+ */
+function shift(set) {
+  let iter = set.values();
+  let { value, done } = iter.next();
+
+  if (done) {
+    return undefined;
+  }
+
+  set.delete(value);
+  return value;
+}
+
+/**
+ * A manager for hidden browsers. Responsible for creating and destroying a
+ * hidden frame to hold them.
+ */
+class HiddenBrowserManager {
+  /**
+   * The hidden frame if one has been created.
+   *
+   * @type {HiddenFrame | null}
+   */
+  #frame = null;
+  /**
+   * The number of hidden browser elements currently in use.
+   *
+   * @type {number}
+   */
+  #browsers = 0;
+
+  /**
+   * Creates and returns a new hidden browser.
+   *
+   * @returns {Browser}
+   */
+  async #acquireBrowser() {
+    this.#browsers++;
+    if (!this.#frame) {
+      this.#frame = new lazy.HiddenFrame();
+    }
+
+    let frame = await this.#frame.get();
+    let doc = frame.document;
+    let browser = doc.createXULElement("browser");
+    browser.setAttribute("remote", "true");
+    browser.setAttribute("type", "content");
+    browser.setAttribute(
+      "style",
+      `
+        width: ${BACKGROUND_WIDTH}px;
+        min-width: ${BACKGROUND_WIDTH}px;
+        height: ${BACKGROUND_HEIGHT}px;
+        min-height: ${BACKGROUND_HEIGHT}px;
+      `
+    );
+    browser.setAttribute("maychangeremoteness", "true");
+    doc.documentElement.appendChild(browser);
+
+    return browser;
+  }
+
+  /**
+   * Releases the given hidden browser.
+   *
+   * @param {Browser} browser
+   *   The hidden browser element.
+   */
+  #releaseBrowser(browser) {
+    browser.remove();
+
+    this.#browsers--;
+    if (this.#browsers == 0) {
+      this.#frame.destroy();
+      this.#frame = null;
+    }
+  }
+
+  /**
+   * Calls a callback function with a new hidden browser.
+   * This function will return whatever the callback function returns.
+   *
+   * @param {Callback} callback
+   *   The callback function will be called with the browser element and may
+   *   be asynchronous.
+   * @returns {T}
+   */
+  async withHiddenBrowser(callback) {
+    let browser = await this.#acquireBrowser();
+    try {
+      return await callback(browser);
+    } finally {
+      this.#releaseBrowser(browser);
+    }
+  }
+}
+
+/**
+ * @typedef {object} CacheEntry
+ *   An entry in the page data cache.
+ * @property {PageData | null} pageData
+ *   The data or null if there is no known data.
+ * @property {Set} actors
+ *   The actors that maintain an interest in keeping the entry cached.
+ */
+
+/**
+ * A cache of page data kept in memory. By default any discovered data from
+ * browsers is kept in memory until the browser element is destroyed but other
+ * actors may register an interest in keeping an entry alive beyond that.
+ */
+class PageDataCache {
+  /**
+   * The contents of the cache. Keyed on page url.
+   *
+   * @type {Map<string, CacheEntry>}
+   */
+  #cache = new Map();
+
+  /**
+   * Creates or updates an entry in the cache. If no actor has registered any
+   * interest in keeping this page's data in memory then this will do nothing.
+   *
+   * @param {string} url
+   *   The url of the page.
+   * @param {PageData|null} pageData
+   *   The current page data for the page.
+   */
+  set(url, pageData) {
+    let entry = this.#cache.get(url);
+
+    if (entry) {
+      entry.pageData = pageData;
+    }
+  }
+
+  /**
+   * Gets any cached data for the url.
+   *
+   * @param {string} url
+   *   The url of the page.
+   * @returns {PageData | null}
+   *   The page data if some is known.
+   */
+  get(url) {
+    let entry = this.#cache.get(url);
+    return entry?.pageData ?? null;
+  }
+
+  /**
+   * Adds a lock to an entry. This can be called before we have discovered the
+   * data for the url.
+   *
+   * @param {object} actor
+   *   Ensures the entry stays in memory until unlocked by this actor.
+   * @param {string} url
+   *   The url of the page.
+   */
+  lockData(actor, url) {
+    let entry = this.#cache.get(url);
+    if (entry) {
+      entry.actors.add(actor);
+    } else {
+      this.#cache.set(url, {
+        pageData: undefined,
+        actors: new Set([actor]),
+      });
+    }
+  }
+
+  /**
+   * Removes a lock from an entry.
+   *
+   * @param {object} actor
+   *   The lock to remove.
+   * @param {string | undefined} [url]
+   *   The url of the page or undefined to unlock all urls locked by this actor.
+   */
+  unlockData(actor, url) {
+    let entries = [];
+    if (url) {
+      let entry = this.#cache.get(url);
+      if (!entry) {
+        return;
+      }
+
+      entries.push([url, entry]);
+    } else {
+      entries = [...this.#cache];
+    }
+
+    for (let [entryUrl, entry] of entries) {
+      if (entry.actors.delete(actor)) {
+        if (entry.actors.size == 0) {
+          this.#cache.delete(entryUrl);
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @typedef {object} PageData
+ *   A set of discovered from a page. Other than the `data` property this is the
+ *   schema at `browser/components/pagedata/schemas/general.schema.json`.
+ * @property {string} url
+ *   The page's url.
+ * @property {number} date
+ *   The epoch based timestamp for when the data was discovered.
+ * @property {string} siteName
+ *   The page's friendly site name.
+ * @property {string} image
+ *   The page's image.
+ * @property {object} data
+ *   The map of data found which may be empty if no data was found. The key in
+ *   map is from the `PageDataSchema.DATA_TYPE` enumeration. The values are in
+ *   the format defined by the schemas at `browser/components/pagedata/schemas`.
+ */
+
+export const PageDataService = new (class PageDataService extends EventEmitter {
+  /**
+   * Caches page data discovered from browsers.
+   *
+   * @type {PageDataCache}
+   */
+  #pageDataCache = new PageDataCache();
+
+  /**
+   * The number of currently running background fetches.
+   *
+   * @type {number}
+   */
+  #backgroundFetches = 0;
+
+  /**
+   * The list of urls waiting to be loaded in the background.
+   *
+   * @type {Set<string>}
+   */
+  #backgroundQueue = new Set();
+
+  /**
+   * Tracks whether the user is currently idle.
+   *
+   * @type {boolean}
+   */
+  #userIsIdle = false;
+
+  /**
+   * A manager for hidden browsers.
+   *
+   * @type {HiddenBrowserManager}
+   */
+  #browserManager = new HiddenBrowserManager();
+
+  /**
+   * A map of hidden browsers to a resolve function that should be passed the
+   * actor that was created for the browser.
+   *
+   * @type {WeakMap<Browser, function(PageDataParent): void>}
+   */
+  #backgroundBrowsers = new WeakMap();
+
+  /**
+   * Tracks windows that have browsers with entries in the cache.
+   *
+   * @type {Map<Window, Set<Browser>>}
+   */
+  #trackedWindows = new Map();
+
+  /**
+   * Constructs the service.
+   */
+  constructor() {
+    super();
+
+    // Limits the number of background fetches that will run at once. Set to 0 to
+    // effectively allow an infinite number.
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "MAX_BACKGROUND_FETCHES",
+      "browser.pagedata.maxBackgroundFetches",
+      5,
+      () => this.#startBackgroundWorkers()
+    );
+  }
+
+  /**
+   * Initializes a new instance of the service, not called externally.
+   */
+  init() {
+    if (!Services.prefs.getBoolPref("browser.pagedata.enabled", false)) {
+      return;
+    }
+
+    ChromeUtils.registerWindowActor("PageData", {
+      parent: {
+        esModuleURI: "resource:///actors/PageDataParent.sys.mjs",
+      },
+      child: {
+        esModuleURI: "resource:///actors/PageDataChild.sys.mjs",
+        events: {
+          DOMContentLoaded: {},
+          pageshow: {},
+        },
+      },
+    });
+
+    lazy.logConsole.debug("Service started");
+
+    for (let win of lazy.BrowserWindowTracker.orderedWindows) {
+      if (!win.closed) {
+        // Ask any existing tabs to report
+        for (let tab of win.gBrowser.tabs) {
+          let parent =
+            tab.linkedBrowser.browsingContext?.currentWindowGlobal.getActor(
+              "PageData"
+            );
+
+          parent.sendAsyncMessage("PageData:CheckLoaded");
+        }
+      }
+    }
+
+    lazy.idleService.addIdleObserver(this, lazy.fetchIdleTime);
+  }
+
+  /**
+   * Called when the service is destroyed. This is generally on shutdown so we
+   * don't really need to do much cleanup.
+   */
+  uninit() {
+    lazy.logConsole.debug("Service stopped");
+  }
+
+  /**
+   * Starts tracking for when a browser is destroyed.
+   *
+   * @param {Browser} browser
+   *   The browser to track.
+   */
+  #trackBrowser(browser) {
+    let window = browser.ownerGlobal;
+
+    let browsers = this.#trackedWindows.get(window);
+    if (browsers) {
+      browsers.add(browser);
+
+      // This window is already being tracked, no need to add listeners.
+      return;
+    }
+
+    browsers = new Set([browser]);
+    this.#trackedWindows.set(window, browsers);
+
+    window.addEventListener("unload", () => {
+      for (let closedBrowser of browsers) {
+        this.unlockEntry(closedBrowser);
+      }
+
+      this.#trackedWindows.delete(window);
+    });
+
+    window.addEventListener("TabClose", ({ target: tab }) => {
+      // Unlock any entries locked by this browser.
+      let closedBrowser = tab.linkedBrowser;
+      this.unlockEntry(closedBrowser);
+      browsers.delete(closedBrowser);
+    });
+  }
+
+  /**
+   * Requests that any page data for this url is retained in memory until
+   * unlocked. By calling this you are committing to later call `unlockEntry`
+   * with the same `actor` and `url` parameters.
+   *
+   * @param {object} actor
+   *   The actor requesting the lock.
+   * @param {string} url
+   *   The url of the page to lock.
+   */
+  lockEntry(actor, url) {
+    this.#pageDataCache.lockData(actor, url);
+  }
+
+  /**
+   * Notifies that an actor is no longer interested in a url.
+   *
+   * @param {object} actor
+   *   The actor that requested the lock.
+   * @param {string | undefined} [url]
+   *   The url of the page or undefined to unlock all urls locked by this actor.
+   */
+  unlockEntry(actor, url) {
+    this.#pageDataCache.unlockData(actor, url);
+  }
+
+  /**
+   * Called when the content process signals that a page is ready for data
+   * collection.
+   *
+   * @param {PageDataParent} actor
+   *   The parent actor for the page.
+   * @param {string} url
+   *   The url of the page.
+   */
+  async pageLoaded(actor, url) {
+    let uri = Services.io.newURI(url);
+    if (!ALLOWED_SCHEMES.includes(uri.scheme)) {
+      return;
+    }
+
+    let browser = actor.browsingContext?.embedderElement;
+
+    // If we don't have a browser then it went away before we could record,
+    // so we don't know where the data came from.
+    if (!browser) {
+      return;
+    }
+
+    // Is this a load in a background browser?
+    let backgroundResolve = this.#backgroundBrowsers.get(browser);
+    if (backgroundResolve) {
+      backgroundResolve(actor);
+      return;
+    }
+
+    // Otherwise we only care about pages loaded in the tab browser.
+    if (!this.#isATabBrowser(browser)) {
+      return;
+    }
+
+    try {
+      let data = await actor.collectPageData();
+      if (data) {
+        // Keep this data alive until the browser is destroyed.
+        this.#trackBrowser(browser);
+        this.lockEntry(browser, data.url);
+
+        this.pageDataDiscovered(data);
+      }
+    } catch (e) {
+      lazy.logConsole.error(e);
+    }
+  }
+
+  /**
+   * Adds data for a url. This should generally only be called by other components of the
+   * page data service or tests for simulating page data collection.
+   *
+   * @param {PageData} pageData
+   *   The set of data discovered.
+   */
+  pageDataDiscovered(pageData) {
+    lazy.logConsole.debug("Discovered page data", pageData);
+
+    this.#pageDataCache.set(pageData.url, {
+      ...pageData,
+      data: pageData.data ?? {},
+    });
+
+    // Send out a notification.
+    this.emit("page-data", pageData);
+  }
+
+  /**
+   * Retrieves any cached page data. Returns null if there is no information in the cache, this will
+   * happen either if the page has not been browsed recently or if data collection failed for some
+   * reason.
+   *
+   * @param {string} url
+   *   The url to retrieve data for.
+   * @returns {PageData|null}
+   *   A `PageData` if one is cached (it may not actually contain any items of data) or null if this
+   *   page has not been successfully checked for data recently.
+   */
+  getCached(url) {
+    return this.#pageDataCache.get(url);
+  }
+
+  /**
+   * Fetches page data from the given URL using a hidden window. Note that this does not populate
+   * the page data cache or emit the `page-data` event.
+   *
+   * @param {string} url
+   *   The url to retrieve data for.
+   * @returns {Promise<PageData|null>}
+   *   Resolves to the found pagedata or null in case of error.
+   */
+  async fetchPageData(url) {
+    return this.#browserManager.withHiddenBrowser(async browser => {
+      try {
+        let { promise, resolve } = lazy.PromiseUtils.defer();
+        this.#backgroundBrowsers.set(browser, resolve);
+
+        let principal = Services.scriptSecurityManager.getSystemPrincipal();
+        let oa = lazy.E10SUtils.predictOriginAttributes({
+          browser,
+        });
+        let loadURIOptions = {
+          triggeringPrincipal: principal,
+          remoteType: lazy.E10SUtils.getRemoteTypeForURI(
+            url,
+            true,
+            false,
+            lazy.E10SUtils.DEFAULT_REMOTE_TYPE,
+            null,
+            oa
+          ),
+        };
+        browser.fixupAndLoadURIString(url, loadURIOptions);
+
+        let actor = await promise;
+        return await actor.collectPageData();
+      } finally {
+        this.#backgroundBrowsers.delete(browser);
+      }
+    });
+  }
+
+  /**
+   * Handles notifications from the idle service.
+   *
+   * @param {nsISupports} subject
+   *   The notification's subject.
+   * @param {string} topic
+   *   The notification topic.
+   * @param {string} data
+   *   The data associated with the notification.
+   */
+  observe(subject, topic, data) {
+    switch (topic) {
+      case "idle":
+        lazy.logConsole.debug("User went idle");
+        this.#userIsIdle = true;
+        this.#startBackgroundWorkers();
+        break;
+      case "active":
+        lazy.logConsole.debug("User became active");
+        this.#userIsIdle = false;
+        break;
+    }
+  }
+
+  /**
+   * Starts as many background workers as are allowed to process the background
+   * queue.
+   */
+  #startBackgroundWorkers() {
+    if (!this.#userIsIdle) {
+      return;
+    }
+
+    let toStart;
+
+    if (this.MAX_BACKGROUND_FETCHES) {
+      toStart = this.MAX_BACKGROUND_FETCHES - this.#backgroundFetches;
+    } else {
+      toStart = this.#backgroundQueue.size;
+    }
+
+    for (let i = 0; i < toStart; i++) {
+      this.#backgroundFetch();
+    }
+  }
+
+  /**
+   * Starts a background fetch worker which will pull urls from the queue and
+   * load them until the queue is empty.
+   */
+  async #backgroundFetch() {
+    this.#backgroundFetches++;
+
+    let url = shift(this.#backgroundQueue);
+    while (url) {
+      try {
+        let pageData = await this.fetchPageData(url);
+
+        if (pageData) {
+          this.#pageDataCache.set(url, pageData);
+          this.emit("page-data", pageData);
+        }
+      } catch (e) {
+        lazy.logConsole.error(e);
+      }
+
+      // Check whether the user became active or the worker limit changed
+      // dynamically.
+      if (
+        !this.#userIsIdle ||
+        (this.MAX_BACKGROUND_FETCHES > 0 &&
+          this.#backgroundFetches > this.MAX_BACKGROUND_FETCHES)
+      ) {
+        break;
+      }
+
+      url = shift(this.#backgroundQueue);
+    }
+
+    this.#backgroundFetches--;
+  }
+
+  /**
+   * Queues page data retrieval for a url. The page-data notification will be
+   * generated if data becomes available.
+   *
+   * Check `getCached` first to ensure that data is not already in the cache.
+   *
+   * @param {string} url
+   *   The url to retrieve data for.
+   */
+  queueFetch(url) {
+    this.#backgroundQueue.add(url);
+
+    this.#startBackgroundWorkers();
+  }
+
+  /**
+   * Determines if the given browser is contained within a tab.
+   *
+   * @param {DOMElement} browser
+   *   The browser element to check.
+   * @returns {boolean}
+   *   True if the browser element is contained within a tab.
+   */
+  #isATabBrowser(browser) {
+    return browser.ownerGlobal.gBrowser?.getTabForBrowser(browser);
+  }
+})();