Bug 1137353 - Port client ID loading mechanism to a stand alone module. r=gfritzsche

toolkit/modules/ClientID.jsm

@@ -0,0 +1,165 @@
+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["ClientID"];
+
+const {classes: Cc, interfaces: Ci, results: Cr, utils: Cu} = Components;
+
+Cu.import("resource://gre/modules/osfile.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "CommonUtils",
+                                  "resource://services-common/utils.js");
+
+XPCOMUtils.defineLazyGetter(this, "gDatareportingPath", () => {
+  return OS.Path.join(OS.Constants.Path.profileDir, "datareporting");
+});
+
+XPCOMUtils.defineLazyGetter(this, "gStateFilePath", () => {
+  return OS.Path.join(gDatareportingPath, "state.json");
+});
+
+this.ClientID = Object.freeze({
+  /**
+   * This returns a promise resolving to the the stable client ID we use for
+   * data reporting (FHR & Telemetry). Previously exising FHR client IDs are
+   * migrated to this.
+   *
+   * @return {Promise<string>} The stable client ID.
+   */
+  getClientID: function() {
+    return ClientIDImpl.getClientID();
+  },
+
+  /**
+   * Generates a new client ID.
+   * @return {Promise<string>} A promise resolved with the new client id.
+   */
+  resetClientID: function() {
+    return ClientIDImpl.resetClientID();
+  },
+
+  /**
+   * Only used for testing. Invalidates the client ID so that it gets read
+   * again from file.
+   */
+  _reset: function() {
+    return ClientIDImpl._reset();
+  },
+});
+
+let ClientIDImpl = {
+  _clientID: null,
+  _loadClientIdTask: null,
+  _saveClientIdTask: null,
+
+  _loadClientID: function () {
+    if (this._loadClientIdTask) {
+      return this._loadClientIdTask;
+    }
+
+    this._loadClientIdTask = this._doLoadClientID();
+    let clear = () => this._loadClientIdTask = null;
+    this._loadClientIdTask.then(clear, clear);
+    return this._loadClientIdTask;
+  },
+
+  _doLoadClientID: Task.async(function* () {
+    // As we want to correlate FHR and telemetry data (and move towards unifying the two),
+    // we first moved the ID management from the FHR implementation to the datareporting
+    // service, then to a common shared module.
+    // Consequently, we try to import an existing FHR ID, so we can keep using it.
+
+    // Try to load the client id from the DRS state file first.
+    try {
+      let state = yield CommonUtils.readJSON(gStateFilePath);
+      if (state && 'clientID' in state && typeof(state.clientID) == 'string') {
+        this._clientID = state.clientID;
+        return this._clientID;
+      }
+    } catch (e) {
+      // fall through to next option
+    }
+
+    // If we dont have DRS state yet, try to import from the FHR state.
+    try {
+      let fhrStatePath = OS.Path.join(OS.Constants.Path.profileDir, "healthreport", "state.json");
+      let state = yield CommonUtils.readJSON(fhrStatePath);
+      if (state && 'clientID' in state && typeof(state.clientID) == 'string') {
+        this._clientID = state.clientID;
+        this._saveClientID();
+        return this._clientID;
+      }
+    } catch (e) {
+      // fall through to next option
+    }
+
+    // We dont have an id from FHR yet, generate a new ID.
+    this._clientID = CommonUtils.generateUUID();
+    this._saveClientIdTask = this._saveClientID();
+
+    // Wait on persisting the id. Otherwise failure to save the ID would result in
+    // the client creating and subsequently sending multiple IDs to the server.
+    // This would appear as multiple clients submitting similar data, which would
+    // result in orphaning.
+    yield this._saveClientIdTask;
+
+    return this._clientID;
+  }),
+
+  /**
+   * Save the client ID to the client ID file.
+   *
+   * @return {Promise} A promise resolved when the client ID is saved to disk.
+   */
+  _saveClientID: Task.async(function* () {
+    let obj = { clientID: this._clientID };
+    yield OS.File.makeDir(gDatareportingPath);
+    yield CommonUtils.writeJSON(obj, gStateFilePath);
+    this._saveClientIdTask = null;
+  }),
+
+  /**
+   * This returns a promise resolving to the the stable client ID we use for
+   * data reporting (FHR & Telemetry). Previously exising FHR client IDs are
+   * migrated to this.
+   *
+   * @return {Promise<string>} The stable client ID.
+   */
+  getClientID: function() {
+    if (!this._clientID) {
+      return this._loadClientID();
+    }
+
+    return Promise.resolve(this._clientID);
+  },
+
+  /**
+   * Reset the stable client id.
+   *
+   * @return {Promise<string>} The new client ID.
+   */
+  resetClientID: Task.async(function* () {
+    yield this._loadClientIdTask;
+    yield this._saveClientIdTask;
+
+    this._clientID = CommonUtils.generateUUID();
+    this._saveClientIdTask = this._saveClientID();
+    yield this._saveClientIdTask;
+
+    return this._clientID;
+  }),
+
+  /*
+   * Resets the provider. This is for testing only.
+   */
+  _reset: Task.async(function* () {
+    yield this._loadClientIdTask;
+    yield this._saveClientIdTask;
+    this._clientID = null;
+  }),
+};

toolkit/modules/moz.build

@@ -17,6 +17,7 @@ EXTRA_JS_MODULES += [
     'BinarySearch.jsm',
     'BrowserUtils.jsm',
     'CharsetMenu.jsm',
+    'ClientID.jsm',
     'debug.js',
     'DeferredTask.jsm',
     'Deprecated.jsm',