Bug 1122047 - Part 1 - Sketch out Telemetry environment module. r=vladan

toolkit/components/telemetry/TelemetryEnvironment.jsm

@@ -0,0 +1,127 @@
+/* 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 = [
+  "TelemetryEnvironment",
+];
+
+const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/Log.jsm");
+
+const LOGGER_NAME = "Toolkit.Telemetry";
+
+this.TelemetryEnvironment = {
+  _shutdown: true,
+
+  // A map of (sync) listeners that will be called on environment changes.
+  _changeListeners: new Map(),
+  // Async task for collecting the environment data.
+  _collectTask: null,
+  _doNotify: false,
+
+  /**
+   * Initialize TelemetryEnvironment.
+   */
+  init: function () {
+    if (!this._shutdown) {
+      this._log.error("init - Already initialized");
+      return;
+    }
+
+    this._log = Log.repository.getLoggerWithMessagePrefix(LOGGER_NAME, "TelemetryEnvironment::");
+    this._log.trace("init");
+    this._shutdown = false;
+  },
+
+  /**
+   * Shutdown TelemetryEnvironment.
+   * @return Promise<> that is resolved when shutdown is finished.
+   */
+  shutdown: Task.async(function* () {
+    if (this._shutdown) {
+      this._log.error("shutdown - Already shut down");
+      throw new Error("Already shut down");
+    }
+
+    this._log.trace("shutdown");
+    this._shutdown = true;
+    this._changeListeners.clear();
+    yield this._collectTask;
+  }),
+
+  /**
+   * Register a listener for environment changes.
+   * @param name The name of the listener - good for debugging purposes.
+   * @param listener A JS callback function.
+   */
+  registerChangeListener: function (name, listener) {
+    this._log.trace("registerChangeListener for " + name);
+    if (this._shutdown) {
+      this._log.warn("registerChangeListener - already shutdown")
+      return;
+    }
+    this._changeListeners.set(name, listener);
+  },
+
+  /**
+   * Unregister from listening to environment changes.
+   * @param name The name of the listener to remove.
+   */
+  unregisterChangeListener: function (name) {
+    this._log.trace("unregisterChangeListener for " + name);
+    if (this._shutdown) {
+      this._log.warn("registerChangeListener - already shutdown")
+      return;
+    }
+    this._changeListeners.delete(name);
+  },
+
+  /**
+   * Get the environment data in object form.
+   * @return Promise<Object> Resolved with the data on success, otherwise rejected.
+   */
+  getEnvironmentData: function() {
+    if (this._shutdown) {
+      this._log.error("getEnvironmentData - Already shut down");
+      return Promise.reject("Already shutdown");
+    }
+
+    this._log.trace("getEnvironmentData");
+    if (this._collectTask) {
+      return this._collectTask;
+    }
+
+    this._collectTask = this._doGetEnvironmentData();
+    let clear = () => this._collectTask = null;
+    this._collectTask.then(clear, clear);
+    return this._collectTask;
+  },
+
+  _doGetEnvironmentData: Task.async(function* () {
+    this._log.trace("getEnvironmentData");
+    return {};
+  }),
+
+  _onEnvironmentChange: function (what) {
+    this._log.trace("_onEnvironmentChange for " + what);
+    if (this._shutdown) {
+      this._log.trace("_onEnvironmentChange - Already shut down.");
+      return;
+    }
+
+    for (let [name, listener] of this._changeListeners) {
+      try {
+        this._log.debug("_onEnvironmentChange - calling " + name);
+        listener();
+      } catch (e) {
+        this._log.warning("_onEnvironmentChange - listener " + name + " caught error", e);
+      }
+    }
+  },
+};

toolkit/components/telemetry/TelemetryPing.jsm

@@ -46,6 +46,8 @@ XPCOMUtils.defineLazyModuleGetter(this, "TelemetryLog",
                                   "resource://gre/modules/TelemetryLog.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "ThirdPartyCookieProbe",
                                   "resource://gre/modules/ThirdPartyCookieProbe.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "TelemetryEnvironment",
+                                  "resource://gre/modules/TelemetryEnvironment.jsm");
 
 /**
  * Setup Telemetry logging. This function also gets called when loggin related
@@ -346,6 +348,8 @@ let Impl = {
     let delayedTask = new DeferredTask(function* () {
       this._initialized = true;
 
+      yield TelemetryEnvironment.init();
+
       yield TelemetryFile.loadSavedPings();
       // If we have any TelemetryPings lying around, we'll be aggressive
       // and try to send them all off ASAP.
@@ -375,10 +379,17 @@ let Impl = {
 
     }.bind(this), testing ? TELEMETRY_TEST_DELAY : TELEMETRY_DELAY);
 
+    AsyncShutdown.sendTelemetry.addBlocker("TelemetryPing: shutting down",
+                                           () => this.shutdown());
+
     delayedTask.arm();
     return deferred.promise;
   },
 
+  shutdown: function() {
+    return TelemetryEnvironment.shutdown();
+  },
+
   /**
    * This observer drives telemetry.
    */

toolkit/components/telemetry/TelemetrySession.jsm

@@ -965,7 +965,7 @@ let Impl = {
     }
 
     AsyncShutdown.sendTelemetry.addBlocker(
-      "Telemetry: shutting down",
+      "TelemetrySession: shutting down",
       function condition(){
         this.uninstall();
         if (Telemetry.canSend) {

toolkit/components/telemetry/moz.build

@@ -28,6 +28,7 @@ EXTRA_COMPONENTS += [
 ]
 
 EXTRA_JS_MODULES += [
+    'TelemetryEnvironment.jsm',
     'TelemetryFile.jsm',
     'TelemetryLog.jsm',
     'TelemetryStopwatch.jsm',

toolkit/components/telemetry/tests/unit/test_TelemetryEnvironment.js

@@ -0,0 +1,70 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+Cu.import("resource://gre/modules/TelemetryEnvironment.jsm", this);
+
+function run_test() {
+  do_test_pending();
+  do_get_profile();
+  run_next_test();
+}
+
+function isRejected(promise) {
+  return new Promise((resolve, reject) => {
+    promise.then(() => resolve(false), () => resolve(true));
+  });
+}
+
+add_task(function* test_initAndShutdown() {
+  // Check that init and shutdown work properly.
+  TelemetryEnvironment.init();
+  yield TelemetryEnvironment.shutdown();
+  TelemetryEnvironment.init();
+  yield TelemetryEnvironment.shutdown();
+
+  // A double init should be silently handled.
+  TelemetryEnvironment.init();
+  TelemetryEnvironment.init();
+
+  // getEnvironmentData should return a sane result.
+  let data = yield TelemetryEnvironment.getEnvironmentData();
+  Assert.ok(!!data);
+
+  // The change listener registration should silently fail after shutdown.
+  yield TelemetryEnvironment.shutdown();
+  TelemetryEnvironment.registerChangeListener("foo", () => {});
+  TelemetryEnvironment.unregisterChangeListener("foo");
+
+  // Other calls after shutdown should reject.
+  Assert.ok(yield isRejected(TelemetryEnvironment.shutdown()));
+  Assert.ok(yield isRejected(TelemetryEnvironment.getEnvironmentData()));
+});
+
+add_task(function* test_changeNotify() {
+  TelemetryEnvironment.init();
+
+  // Register some listeners
+  let results = new Array(4).fill(false);
+  for (let i=0; i<results.length; ++i) {
+    let k = i;
+    TelemetryEnvironment.registerChangeListener("test"+k, () => results[k] = true);
+  }
+  // Trigger environment change notifications.
+  // TODO: test with proper environment changes, not directly.
+  TelemetryEnvironment._onEnvironmentChange("foo");
+  Assert.ok(results.every(val => val), "All change listeners should have been notified.");
+  results.fill(false);
+  TelemetryEnvironment._onEnvironmentChange("bar");
+  Assert.ok(results.every(val => val), "All change listeners should have been notified.");
+
+  // Unregister listeners
+  for (let i=0; i<4; ++i) {
+    TelemetryEnvironment.unregisterChangeListener("test"+i);
+  }
+});
+
+add_task(function*() {
+  do_test_finished();
+});

toolkit/components/telemetry/tests/unit/xpcshell.ini

@@ -4,6 +4,7 @@ tail =
 skip-if = toolkit == 'gonk'
 
 [test_nsITelemetry.js]
+[test_TelemetryEnvironment.js]
 [test_TelemetryFlagClear.js]
 [test_TelemetryLateWrites.js]
 [test_TelemetryLockCount.js]