1 files changed, 407 insertions, 0 deletions
diff --git a/toolkit/components/backgroundtasks/BackgroundTasksUtils.sys.mjs b/toolkit/components/backgroundtasks/BackgroundTasksUtils.sys.mjs
new file mode 100644
index 0000000000..9521af5a56
--- /dev/null
+++ b/toolkit/components/backgroundtasks/BackgroundTasksUtils.sys.mjs
@@ -0,0 +1,407 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * 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";
+
+const lazy = {};
+
+ChromeUtils.defineLazyGetter(lazy, "log", () => {
+  let { ConsoleAPI } = ChromeUtils.importESModule(
+    "resource://gre/modules/Console.sys.mjs"
+  );
+  let consoleOptions = {
+    // tip: set maxLogLevel to "debug" and use log.debug() to create detailed
+    // messages during development. See LOG_LEVELS in Console.sys.mjs for details.
+    maxLogLevel: "error",
+    maxLogLevelPref: "toolkit.backgroundtasks.loglevel",
+    prefix: "BackgroundTasksUtils",
+  };
+  return new ConsoleAPI(consoleOptions);
+});
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "ProfileService",
+  "@mozilla.org/toolkit/profile-service;1",
+  "nsIToolkitProfileService"
+);
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  ASRouter:
+    // eslint-disable-next-line mozilla/no-browser-refs-in-toolkit
+    "resource:///modules/asrouter/ASRouter.sys.mjs",
+  ASRouterDefaultConfig:
+    // eslint-disable-next-line mozilla/no-browser-refs-in-toolkit
+    "resource:///modules/asrouter/ASRouterDefaultConfig.sys.mjs",
+
+  ExperimentManager: "resource://nimbus/lib/ExperimentManager.sys.mjs",
+
+  RemoteSettingsExperimentLoader:
+    "resource://nimbus/lib/RemoteSettingsExperimentLoader.sys.mjs",
+});
+
+class CannotLockProfileError extends Error {
+  constructor(message) {
+    super(message);
+    this.name = "CannotLockProfileError";
+  }
+}
+
+export var BackgroundTasksUtils = {
+  // Manage our own default profile that can be overridden for testing.  It's
+  // easier to do this here rather than using the profile service itself.
+  _defaultProfileInitialized: false,
+  _defaultProfile: null,
+
+  getDefaultProfile() {
+    if (!this._defaultProfileInitialized) {
+      this._defaultProfileInitialized = true;
+      // This is all test-only.
+      let defaultProfilePath = Services.env.get(
+        "MOZ_BACKGROUNDTASKS_DEFAULT_PROFILE_PATH"
+      );
+      let noDefaultProfile = Services.env.get(
+        "MOZ_BACKGROUNDTASKS_NO_DEFAULT_PROFILE"
+      );
+      if (defaultProfilePath) {
+        lazy.log.info(
+          `getDefaultProfile: using default profile path ${defaultProfilePath}`
+        );
+        var tmpd = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+        tmpd.initWithPath(defaultProfilePath);
+        // Sadly this writes to `profiles.ini`, but there's little to be done.
+        this._defaultProfile = lazy.ProfileService.createProfile(
+          tmpd,
+          `MOZ_BACKGROUNDTASKS_DEFAULT_PROFILE_PATH-${Date.now()}`
+        );
+      } else if (noDefaultProfile) {
+        lazy.log.info(`getDefaultProfile: setting default profile to null`);
+        this._defaultProfile = null;
+      } else {
+        try {
+          lazy.log.info(
+            `getDefaultProfile: using ProfileService.defaultProfile`
+          );
+          this._defaultProfile = lazy.ProfileService.defaultProfile;
+        } catch (e) {}
+      }
+    }
+    return this._defaultProfile;
+  },
+
+  hasDefaultProfile() {
+    return this.getDefaultProfile() != null;
+  },
+
+  currentProfileIsDefaultProfile() {
+    let defaultProfile = this.getDefaultProfile();
+    let currentProfile = lazy.ProfileService.currentProfile;
+    // This comparison needs to accommodate null on both sides.
+    let isDefaultProfile = defaultProfile && currentProfile == defaultProfile;
+    return isDefaultProfile;
+  },
+
+  _throwIfNotLocked(lock) {
+    if (!(lock instanceof Ci.nsIProfileLock)) {
+      throw new Error("Passed lock was not an instance of nsIProfileLock");
+    }
+
+    try {
+      // In release builds, `.directory` throws NS_ERROR_NOT_INITIALIZED when
+      // unlocked.  In debug builds, `.directory` when the profile is not locked
+      // will crash via `NS_ERROR`.
+      if (lock.directory) {
+        return;
+      }
+    } catch (e) {
+      if (
+        !(
+          e instanceof Ci.nsIException &&
+          e.result == Cr.NS_ERROR_NOT_INITIALIZED
+        )
+      ) {
+        throw e;
+      }
+    }
+    throw new Error("Profile is not locked");
+  },
+
+  /**
+   * Locks the given profile and provides the path to it to the callback.
+   * The callback should return a promise and once settled the profile is
+   * unlocked and then the promise returned back to the caller of this function.
+   *
+   * @template T
+   * @param {(lock: nsIProfileLock) => Promise<T>} callback
+   * @param {nsIToolkitProfile} [profile] defaults to default profile
+   * @return {Promise<T>}
+   */
+  async withProfileLock(callback, profile = this.getDefaultProfile()) {
+    if (!profile) {
+      throw new Error("No default profile exists");
+    }
+
+    let lock;
+    try {
+      lock = profile.lock({});
+      lazy.log.info(
+        `withProfileLock: locked profile at ${lock.directory.path}`
+      );
+    } catch (e) {
+      throw new CannotLockProfileError(`Cannot lock profile: ${e}`);
+    }
+
+    try {
+      // We must await to ensure any logging is displayed after the callback resolves.
+      return await callback(lock);
+    } finally {
+      try {
+        lazy.log.info(
+          `withProfileLock: unlocking profile at ${lock.directory.path}`
+        );
+        lock.unlock();
+        lazy.log.info(`withProfileLock: unlocked profile`);
+      } catch (e) {
+        lazy.log.warn(`withProfileLock: error unlocking profile`, e);
+      }
+    }
+  },
+
+  /**
+   * Reads the preferences from "prefs.js" out of a profile, optionally
+   * returning only names satisfying a given predicate.
+   *
+   * If no `lock` is given, the default profile is locked and the preferences
+   * read from it.  If `lock` is given, read from the given lock's directory.
+   *
+   * @param {(name: string) => boolean} [predicate] a predicate to filter
+   * preferences by; if not given, all preferences are accepted.
+   * @param {nsIProfileLock} [lock] optional lock to use
+   * @returns {object} with keys that are string preference names and values
+   * that are string|number|boolean preference values.
+   */
+  async readPreferences(predicate = null, lock = null) {
+    if (!lock) {
+      return this.withProfileLock(profileLock =>
+        this.readPreferences(predicate, profileLock)
+      );
+    }
+
+    this._throwIfNotLocked(lock);
+    lazy.log.info(`readPreferences: profile is locked`);
+
+    let prefs = {};
+    let addPref = (kind, name, value, sticky, locked) => {
+      if (predicate && !predicate(name)) {
+        return;
+      }
+      prefs[name] = value;
+    };
+
+    // We ignore any "user.js" file, since usage is low and doing otherwise
+    // requires implementing a bit more of `nsIPrefsService` than feels safe.
+    let prefsFile = lock.directory.clone();
+    prefsFile.append("prefs.js");
+    lazy.log.info(`readPreferences: will parse prefs ${prefsFile.path}`);
+
+    let data = await IOUtils.read(prefsFile.path);
+    lazy.log.debug(
+      `readPreferences: parsing prefs from buffer of length ${data.length}`
+    );
+
+    Services.prefs.parsePrefsFromBuffer(
+      data,
+      {
+        onStringPref: addPref,
+        onIntPref: addPref,
+        onBoolPref: addPref,
+        onError(message) {
+          // Firefox itself manages "prefs.js", so errors should be infrequent.
+          lazy.log.error(message);
+        },
+      },
+      prefsFile.path
+    );
+
+    lazy.log.debug(`readPreferences: parsed prefs from buffer`, prefs);
+    return prefs;
+  },
+
+  /**
+   * Reads the snapshotted Firefox Messaging System targeting out of a profile.
+   *
+   * If no `lock` is given, the default profile is locked and the preferences
+   * read from it.  If `lock` is given, read from the given lock's directory.
+   *
+   * @param {nsIProfileLock} [lock] optional lock to use
+   * @returns {object}
+   */
+  async readFirefoxMessagingSystemTargetingSnapshot(lock = null) {
+    if (!lock) {
+      return this.withProfileLock(profileLock =>
+        this.readFirefoxMessagingSystemTargetingSnapshot(profileLock)
+      );
+    }
+
+    this._throwIfNotLocked(lock);
+
+    let snapshotFile = lock.directory.clone();
+    snapshotFile.append("targeting.snapshot.json");
+
+    lazy.log.info(
+      `readFirefoxMessagingSystemTargetingSnapshot: will read Firefox Messaging ` +
+        `System targeting snapshot from ${snapshotFile.path}`
+    );
+
+    return IOUtils.readJSON(snapshotFile.path);
+  },
+
+  /**
+   * Reads the Telemetry Client ID out of a profile.
+   *
+   * If no `lock` is given, the default profile is locked and the preferences
+   * read from it.  If `lock` is given, read from the given lock's directory.
+   *
+   * @param {nsIProfileLock} [lock] optional lock to use
+   * @returns {string}
+   */
+  async readTelemetryClientID(lock = null) {
+    if (!lock) {
+      return this.withProfileLock(profileLock =>
+        this.readTelemetryClientID(profileLock)
+      );
+    }
+
+    this._throwIfNotLocked(lock);
+
+    let stateFile = lock.directory.clone();
+    stateFile.append("datareporting");
+    stateFile.append("state.json");
+
+    lazy.log.info(
+      `readPreferences: will read Telemetry client ID from ${stateFile.path}`
+    );
+
+    let state = await IOUtils.readJSON(stateFile.path);
+
+    return state.clientID;
+  },
+
+  /**
+   * Enable the Nimbus experimentation framework.
+   *
+   * @param {nsICommandLine} commandLine if given, accept command line parameters
+   *                                     like `--url about:studies?...` or
+   *                                     `--url file:path/to.json` to explicitly
+   *                                     opt-on to experiment branches.
+   * @param {object} defaultProfile      snapshot of Firefox Messaging System
+   *                                     targeting from default browsing profile.
+   */
+  async enableNimbus(commandLine, defaultProfile = {}) {
+    try {
+      await lazy.ExperimentManager.onStartup({ defaultProfile });
+    } catch (err) {
+      lazy.log.error("Failed to initialize ExperimentManager:", err);
+      throw err;
+    }
+
+    try {
+      await lazy.RemoteSettingsExperimentLoader.init({ forceSync: true });
+    } catch (err) {
+      lazy.log.error(
+        "Failed to initialize RemoteSettingsExperimentLoader:",
+        err
+      );
+      throw err;
+    }
+
+    // Allow manual explicit opt-in to experiment branches to facilitate testing.
+    //
+    // Process command line arguments, like
+    // `--url about:studies?optin_slug=nalexander-ms-test1&optin_branch=treatment-a&optin_collection=nimbus-preview`
+    // or
+    // `--url file:///Users/nalexander/Mozilla/gecko/experiment.json?optin_branch=treatment-a`.
+    let ar;
+    while ((ar = commandLine?.handleFlagWithParam("url", false))) {
+      let uri = commandLine.resolveURI(ar);
+      const params = new URLSearchParams(uri.query);
+
+      if (uri.schemeIs("about") && uri.filePath == "studies") {
+        // Allow explicit opt-in.  In the future, we might take this pref from
+        // the default browsing profile.
+        Services.prefs.setBoolPref("nimbus.debug", true);
+
+        const data = {
+          slug: params.get("optin_slug"),
+          branch: params.get("optin_branch"),
+          collection: params.get("optin_collection"),
+        };
+        await lazy.RemoteSettingsExperimentLoader.optInToExperiment(data);
+        lazy.log.info(`Opted in to experiment: ${JSON.stringify(data)}`);
+      }
+
+      if (uri.schemeIs("file")) {
+        let branchSlug = params.get("optin_branch");
+        let path = decodeURIComponent(uri.filePath);
+        let response = await fetch(uri.spec);
+        let recipe = await response.json();
+        if (recipe.permissions) {
+          // Saved directly from Experimenter, there's a top-level `data`.  Hand
+          // written, that's not the norm.
+          recipe = recipe.data;
+        }
+        let branch = recipe.branches.find(b => b.slug == branchSlug);
+
+        lazy.ExperimentManager.forceEnroll(recipe, branch);
+        lazy.log.info(`Forced enrollment into: ${path}, branch: ${branchSlug}`);
+      }
+    }
+  },
+
+  /**
+   * Enable the Firefox Messaging System and, when successfully initialized,
+   * trigger a message with trigger id `backgroundTask`.
+   *
+   * @param {object} defaultProfile - snapshot of Firefox Messaging System
+   *                                  targeting from default browsing profile.
+   */
+  async enableFirefoxMessagingSystem(defaultProfile = {}) {
+    function logArgs(tag, ...args) {
+      lazy.log.debug(`FxMS invoked ${tag}: ${JSON.stringify(args)}`);
+    }
+
+    let { messageHandler, router, createStorage } =
+      lazy.ASRouterDefaultConfig();
+
+    if (!router.initialized) {
+      const storage = await createStorage();
+      await router.init({
+        storage,
+        // Background tasks never send legacy telemetry.
+        sendTelemetry: logArgs.bind(null, "sendTelemetry"),
+        dispatchCFRAction: messageHandler.handleCFRAction.bind(messageHandler),
+        // There's no child process involved in background tasks, so swallow all
+        // of these messages.
+        clearChildMessages: logArgs.bind(null, "clearChildMessages"),
+        clearChildProviders: logArgs.bind(null, "clearChildProviders"),
+        updateAdminState: () => {},
+      });
+    }
+
+    await lazy.ASRouter.waitForInitialized;
+
+    const triggerId = "backgroundTask";
+    await lazy.ASRouter.sendTriggerMessage({
+      browser: null,
+      id: triggerId,
+      context: {
+        defaultProfile,
+      },
+    });
+    lazy.log.info(
+      "Triggered Firefox Messaging System with trigger id 'backgroundTask'"
+    );
+  },
+};