Bug 1225690 - implement a SyncedTabs module to abstract away Sync's internals. r=rnewman

services/sync/modules/SyncedTabs.jsm

@@ -0,0 +1,267 @@
+/* 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 = ["SyncedTabs"];
+
+
+const { classes: Cc, interfaces: Ci, results: Cr, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/Log.jsm");
+Cu.import("resource://gre/modules/PlacesUtils.jsm", this);
+Cu.import("resource://services-sync/main.js");
+Cu.import("resource://gre/modules/Preferences.jsm");
+
+// The Sync XPCOM service
+XPCOMUtils.defineLazyGetter(this, "weaveXPCService", function() {
+  return Cc["@mozilla.org/weave/service;1"]
+           .getService(Ci.nsISupports)
+           .wrappedJSObject;
+});
+
+// from MDN...
+function escapeRegExp(string) {
+  return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+// A topic we fire whenever we have new tabs available. This might be due
+// to a request made by this module to refresh the tab list, or as the result
+// of a regularly scheduled sync. The intent is that consumers just listen
+// for this notification and update their UI in response.
+const TOPIC_TABS_CHANGED = "services.sync.tabs.changed";
+
+// The interval, in seconds, before which we consider the existing list
+// of tabs "fresh enough" and don't force a new sync.
+const TABS_FRESH_ENOUGH_INTERVAL = 30;
+
+let log = Log.repository.getLogger("Sync.RemoteTabs");
+// A new scope to do the logging thang...
+(function() {
+  let level = Preferences.get("services.sync.log.logger.tabs");
+  if (level) {
+    let appender = new Log.DumpAppender();
+    log.level = appender.level = Log.Level[level] || Log.Level.Debug;
+    log.addAppender(appender);
+  }
+})();
+
+
+// A private singleton that does the work.
+let SyncedTabsInternal = {
+  _getClientIcon(id) {
+    let isMobile = Weave.Service.clientsEngine.isMobile(id);
+    if (isMobile) {
+      return "chrome://browser/skin/sync-mobileIcon.png";
+    }
+    return "chrome://browser/skin/sync-desktopIcon.png";
+  },
+
+  /* Make a "tab" record. Returns a promise */
+  _makeTab: Task.async(function* (client, tab, url) {
+    let icon = tab.icon;
+    if (!icon) {
+      try {
+        icon = (yield PlacesUtils.promiseFaviconLinkUrl(url)).spec;
+      } catch (ex) { /* no favicon avaiable */ }
+    }
+    if (!icon) {
+      icon = PlacesUtils.favicons.defaultFavicon.spec;
+    }
+    return {
+      type:  "tab",
+      title: tab.title || url,
+      url,
+      icon,
+      client: client.id,
+      lastUsed: tab.lastUsed,
+    };
+  }),
+
+  /* Make a "client" record. Returns a promise for consistency with _makeTab */
+  _makeClient: Task.async(function* (client) {
+    return {
+      id: client.id,
+      type: "client",
+      name: client.clientName,
+      icon:  this._getClientIcon(client.id),
+      tabs: []
+    };
+  }),
+
+  _tabMatchesFilter(tab, filter) {
+    let reFilter = new RegExp(escapeRegExp(filter), "i");
+    return tab.url.match(reFilter) || tab.title.match(reFilter);
+  },
+
+  getTabClients: Task.async(function* (filter) {
+    log.info("Generating tab list with filter", filter);
+    let result = [];
+
+    // If Sync isn't ready, don't try and get anything.
+    if (!weaveXPCService.ready) {
+      log.debug("Sync isn't yet ready, so returning an empty tab list");
+      return result;
+    }
+
+    let engine = Weave.Service.engineManager.get("tabs");
+
+    let seenURLs = new Set();
+    let parentIndex = 0;
+    let ntabs = 0;
+
+    for (let [guid, client] in Iterator(engine.getAllClients())) {
+      let clientRepr = yield this._makeClient(client);
+      log.debug("Processing client", clientRepr);
+
+      for (let tab of client.tabs) {
+        let url = tab.urlHistory[0];
+        log.debug("remote tab", url);
+        // Note there are some issues with tracking "seen" tabs, including:
+        // * We really can't return the entire urlHistory record as we are
+        //   only checking the first entry - others might be different.
+        // * We don't update the |lastUsed| timestamp to reflect the
+        //   most-recently-seen time.
+        // In a followup we should consider simply dropping this |seenUrls|
+        // check and return duplicate records - it seems the user will be more
+        // confused by tabs not showing up on a device (because it was detected
+        // as a dupe so it only appears on a different device) than being
+        // confused by seeing the same tab on different clients.
+        if (!url || seenURLs.has(url)) {
+          continue;
+        }
+        let tabRepr = yield this._makeTab(client, tab, url);
+        if (filter && !this._tabMatchesFilter(tabRepr, filter)) {
+          continue;
+        }
+        seenURLs.add(url);
+        clientRepr.tabs.push(tabRepr);
+      }
+      // We return all clients, even those without tabs - the consumer should
+      // filter it if they care.
+      ntabs += clientRepr.tabs.length;
+      result.push(clientRepr);
+    }
+    log.info(`Final tab list has ${result.length} clients with ${ntabs} tabs.`);
+    return result;
+  }),
+
+  syncTabs(force) {
+    if (!force) {
+      // Don't bother refetching tabs if we already did so recently
+      let lastFetch = Preferences.get("services.sync.lastTabFetch", 0);
+      let now = Math.floor(Date.now() / 1000);
+      if (now - lastFetch < TABS_FRESH_ENOUGH_INTERVAL) {
+        log.info("_refetchTabs was done recently, do not doing it again");
+        return Promise.resolve(false);
+      }
+    }
+
+    // If Sync isn't configured don't try and sync, else we will get reports
+    // of a login failure.
+    if (Weave.Status.checkSetup() == Weave.CLIENT_NOT_CONFIGURED) {
+      log.info("Sync client is not configured, so not attempting a tab sync");
+      return Promise.resolve(false);
+    }
+    // Ask Sync to just do the tabs engine if it can.
+    // Sync is currently synchronous, so do it after an event-loop spin to help
+    // keep the UI responsive.
+    return new Promise((resolve, reject) => {
+      Services.tm.currentThread.dispatch(() => {
+        try {
+          log.info("Doing a tab sync.");
+          Weave.Service.sync(["tabs"]);
+          resolve(true);
+        } catch (ex) {
+          log.error("Sync failed", ex);
+          reject(ex);
+        };
+      }, Ci.nsIThread.DISPATCH_NORMAL);
+    });
+  },
+
+  observe(subject, topic, data) {
+    log.trace(`observed topic=${topic}, data=${data}, subject=${subject}`);
+    switch (topic) {
+      case "weave:engine:sync:finish":
+        if (data != "tabs") {
+          return;
+        }
+        // The tabs engine just finished syncing
+        // Set our lastTabFetch pref here so it tracks both explicit sync calls
+        // and normally scheduled ones.
+        Preferences.set("services.sync.lastTabFetch", Math.floor(Date.now() / 1000));
+        Services.obs.notifyObservers(null, TOPIC_TABS_CHANGED, null);
+        break;
+      case "weave:service:start-over":
+        // start-over needs to notify so consumers find no tabs.
+        Preferences.reset("services.sync.lastTabFetch");
+        Services.obs.notifyObservers(null, TOPIC_TABS_CHANGED, null);
+        break;
+      default:
+        break;
+    }
+  },
+
+  // Returns true if Sync is configured to Sync tabs, false otherwise
+  get isConfiguredToSyncTabs() {
+    if (!weaveXPCService.ready) {
+      log.debug("Sync isn't yet ready; assuming tab engine is enabled");
+      return true;
+    }
+
+    let engine = Weave.Service.engineManager.get("tabs");
+    return engine && engine.enabled;
+  },
+
+  get hasSyncedThisSession() {
+    let engine = Weave.Service.engineManager.get("tabs");
+    return engine && engine.hasSyncedThisSession;
+  },
+};
+
+Services.obs.addObserver(SyncedTabsInternal, "weave:engine:sync:finish", false);
+Services.obs.addObserver(SyncedTabsInternal, "weave:service:start-over", false);
+
+// The public interface.
+this.SyncedTabs = {
+  // A mock-point for tests.
+  _internal: SyncedTabsInternal,
+
+  // We make the topic for the observer notification public.
+  TOPIC_TABS_CHANGED,
+
+  // Returns true if Sync is configured to Sync tabs, false otherwise
+  get isConfiguredToSyncTabs() {
+    return this._internal.isConfiguredToSyncTabs;
+  },
+
+  // Returns true if a tab sync has completed once this session. If this
+  // returns false, then getting back no clients/tabs possibly just means we
+  // are waiting for that first sync to complete.
+  get hasSyncedThisSession() {
+    return this._internal.hasSyncedThisSession;
+  },
+
+  // Return a promise that resolves with an array of client records, each with
+  // a .tabs array. Note that part of the contract for this module is that the
+  // returned objects are not shared between invocations, so callers are free
+  // to mutate the returned objects (eg, sort, truncate) however they see fit.
+  getTabClients(query) {
+    return this._internal.getTabClients(query);
+  },
+
+  // Starts a background request to start syncing tabs. Returns a promise that
+  // resolves when the sync is complete, but there's no resolved value -
+  // callers should be listening for TOPIC_TABS_CHANGED.
+  // If |force| is true we always sync. If false, we only sync if the most
+  // recent sync wasn't "recently".
+  syncTabs(force) {
+    return this._internal.syncTabs(force);
+  },
+};
+

services/sync/modules/engines/tabs.js

@@ -43,6 +43,11 @@ TabEngine.prototype = {
   _storeObj: TabStore,
   _trackerObj: TabTracker,
   _recordObj: TabSetRecord,
+  // A flag to indicate if we have synced in this session. This is to help
+  // consumers of remote tabs that may want to differentiate between "I've an
+  // empty tab list as I haven't yet synced" vs "I've an empty tab list
+  // as there really are no tabs"
+  hasSyncedThisSession: false,
 
   syncPriority: 3,
 
@@ -67,6 +72,7 @@ TabEngine.prototype = {
     SyncEngine.prototype._resetClient.call(this);
     this._store.wipe();
     this._tracker.modified = true;
+    this.hasSyncedThisSession = false;
   },
 
   removeClientData: function () {
@@ -94,7 +100,12 @@ TabEngine.prototype = {
     }
 
     return SyncEngine.prototype._reconcile.call(this, item);
-  }
+  },
+
+  _syncFinish() {
+    this.hasSyncedThisSession = true;
+    return SyncEngine.prototype._syncFinish.call(this);
+  },
 };
 
 

services/sync/moz.build

@@ -36,6 +36,7 @@ EXTRA_JS_MODULES['services-sync'] += [
     'modules/rest.js',
     'modules/service.js',
     'modules/status.js',
+    'modules/SyncedTabs.jsm',
     'modules/userapi.js',
     'modules/util.js',
 ]

services/sync/tests/unit/test_syncedtabs.js

@@ -0,0 +1,125 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * vim:set ts=2 sw=2 sts=2 et:
+*/
+"use strict";
+
+Cu.import("resource://services-sync/main.js");
+Cu.import("resource://services-sync/SyncedTabs.jsm");
+Cu.import("resource://gre/modules/Log.jsm");
+
+Log.repository.getLogger("Sync.RemoteTabs").addAppender(new Log.DumpAppender());
+
+// A mock "Tabs" engine which the SyncedTabs module will use instead of the real
+// engine. We pass a constructor that Sync creates.
+function MockTabsEngine() {
+  this.clients = {}; // We'll set this dynamically
+}
+
+MockTabsEngine.prototype = {
+  name: "tabs",
+  enabled: true,
+
+  getAllClients() {
+    return this.clients;
+  },
+
+  getOpenURLs() {
+    return new Set();
+  },
+}
+
+// A clients engine that doesn't need to be a constructor.
+let MockClientsEngine = {
+  isMobile(guid) {
+    if (!guid.endsWith("desktop") && !guid.endsWith("mobile")) {
+      throw new Error("this module expected guids to end with 'desktop' or 'mobile'");
+    }
+    return guid.endsWith("mobile");
+  },
+}
+
+// Configure Sync with our mock tabs engine and force it to become initialized.
+Services.prefs.setCharPref("services.sync.username", "someone@somewhere.com");
+
+Weave.Service.engineManager.unregister("tabs");
+Weave.Service.engineManager.register(MockTabsEngine);
+Weave.Service.clientsEngine = MockClientsEngine;
+
+// Tell the Sync XPCOM service it is initialized.
+let weaveXPCService = Cc["@mozilla.org/weave/service;1"]
+                        .getService(Ci.nsISupports)
+                        .wrappedJSObject;
+weaveXPCService.ready = true;
+
+function configureClients(clients) {
+  // Configure the instance Sync created.
+  let engine = Weave.Service.engineManager.get("tabs");
+  // each client record is expected to have an id.
+  for (let [guid, client] in Iterator(clients)) {
+    client.id = guid;
+  }
+  engine.clients = clients;
+  // Send an observer that pretends the engine just finished a sync.
+  Services.obs.notifyObservers(null, "weave:engine:sync:finish", "tabs");
+}
+
+// The tests.
+add_task(function* test_noClients() {
+  // no clients, can't be tabs.
+  yield configureClients({});
+
+  let tabs = yield SyncedTabs.getTabClients();
+  equal(Object.keys(tabs).length, 0);
+});
+
+add_task(function* test_clientWithTabs() {
+  yield configureClients({
+    guid_desktop: {
+      clientName: "My Desktop",
+      tabs: [
+      {
+        urlHistory: ["http://foo.com/"],
+      }],
+    },
+    guid_mobile: {
+      clientName: "My Phone",
+      tabs: [],
+    }
+  });
+
+  let clients = yield SyncedTabs.getTabClients();
+  equal(clients.length, 2);
+  clients.sort((a, b) => { return a.name.localeCompare(b.name);});
+  equal(clients[0].tabs.length, 1);
+  equal(clients[0].tabs[0].url, "http://foo.com/");
+  // second client has no tabs.
+  equal(clients[1].tabs.length, 0);
+});
+
+add_task(function* test_filter() {
+  // Nothing matches.
+  yield configureClients({
+    guid_desktop: {
+      clientName: "My Desktop",
+      tabs: [
+      {
+        urlHistory: ["http://foo.com/"],
+        title: "A test page.",
+      },
+      {
+        urlHistory: ["http://bar.com/"],
+        title: "Another page.",
+      }],
+    },
+  });
+
+  let clients = yield SyncedTabs.getTabClients("foo");
+  equal(clients.length, 1);
+  equal(clients[0].tabs.length, 1);
+  equal(clients[0].tabs[0].url, "http://foo.com/");
+  // check it matches the title.
+  clients = yield SyncedTabs.getTabClients("test");
+  equal(clients.length, 1);
+  equal(clients[0].tabs.length, 1);
+  equal(clients[0].tabs[0].url, "http://foo.com/");
+});

services/sync/tests/unit/xpcshell.ini

@@ -181,3 +181,6 @@ skip-if = ! healthreport
 
 # FxA migration
 [test_fxa_migration.js]
+
+# Synced tabs.
+[test_syncedtabs.js]