1 files changed, 259 insertions, 0 deletions
diff --git a/browser/components/urlbar/UrlbarProviderRemoteTabs.sys.mjs b/browser/components/urlbar/UrlbarProviderRemoteTabs.sys.mjs
new file mode 100644
index 0000000000..ab5f5fddbf
--- /dev/null
+++ b/browser/components/urlbar/UrlbarProviderRemoteTabs.sys.mjs
@@ -0,0 +1,259 @@
+/* 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/. */
+
+/**
+ * This module exports a provider that offers remote tabs.
+ */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+import {
+  UrlbarProvider,
+  UrlbarUtils,
+} from "resource:///modules/UrlbarUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  PlacesUtils: "resource://gre/modules/PlacesUtils.sys.mjs",
+  UrlbarPrefs: "resource:///modules/UrlbarPrefs.sys.mjs",
+  UrlbarResult: "resource:///modules/UrlbarResult.sys.mjs",
+  UrlbarTokenizer: "resource:///modules/UrlbarTokenizer.sys.mjs",
+});
+
+XPCOMUtils.defineLazyModuleGetters(lazy, {
+  SyncedTabs: "resource://services-sync/SyncedTabs.jsm",
+});
+
+let _cache = null;
+
+// By default, we add remote tabs that have been used more recently than this
+// time ago. Any remaining remote tabs are added in queue if no other results
+// are found.
+const RECENT_REMOTE_TAB_THRESHOLD_MS = 72 * 60 * 60 * 1000; // 72 hours.
+
+XPCOMUtils.defineLazyGetter(lazy, "weaveXPCService", function() {
+  try {
+    return Cc["@mozilla.org/weave/service;1"].getService(
+      Ci.nsISupports
+    ).wrappedJSObject;
+  } catch (ex) {
+    // The app didn't build Sync.
+  }
+  return null;
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "showRemoteIconsPref",
+  "services.sync.syncedTabs.showRemoteIcons",
+  true
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "showRemoteTabsPref",
+  "services.sync.syncedTabs.showRemoteTabs",
+  true
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "syncUsernamePref",
+  "services.sync.username"
+);
+
+// from MDN...
+function escapeRegExp(string) {
+  return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+/**
+ * Class used to create the provider.
+ */
+class ProviderRemoteTabs extends UrlbarProvider {
+  constructor() {
+    super();
+    Services.obs.addObserver(this.observe, "weave:engine:sync:finish");
+    Services.obs.addObserver(this.observe, "weave:service:start-over");
+  }
+
+  /**
+   * Unique name for the provider, used by the context to filter on providers.
+   *
+   * @returns {string}
+   */
+  get name() {
+    return "RemoteTabs";
+  }
+
+  /**
+   * The type of the provider, must be one of UrlbarUtils.PROVIDER_TYPE.
+   *
+   * @returns {UrlbarUtils.PROVIDER_TYPE}
+   */
+  get type() {
+    return UrlbarUtils.PROVIDER_TYPE.NETWORK;
+  }
+
+  /**
+   * Whether this provider should be invoked for the given context.
+   * If this method returns false, the providers manager won't start a query
+   * with this provider, to save on resources.
+   *
+   * @param {UrlbarQueryContext} queryContext The query context object
+   * @returns {boolean} Whether this provider should be invoked for the search.
+   */
+  isActive(queryContext) {
+    return (
+      lazy.syncUsernamePref &&
+      lazy.showRemoteTabsPref &&
+      lazy.UrlbarPrefs.get("suggest.remotetab") &&
+      queryContext.sources.includes(UrlbarUtils.RESULT_SOURCE.TABS) &&
+      lazy.weaveXPCService &&
+      lazy.weaveXPCService.ready &&
+      lazy.weaveXPCService.enabled
+    );
+  }
+
+  /**
+   * Starts querying. Extended classes should return a Promise resolved when the
+   * provider is done searching AND returning results.
+   *
+   * @param {UrlbarQueryContext} queryContext The query context object
+   * @param {Function} addCallback Callback invoked by the provider to add a new
+   *        result. A UrlbarResult should be passed to it.
+   */
+  async startQuery(queryContext, addCallback) {
+    let instance = this.queryInstance;
+
+    let searchString = queryContext.tokens.map(t => t.value).join(" ");
+
+    let re = new RegExp(escapeRegExp(searchString), "i");
+    let tabsData = await this.ensureCache();
+    if (instance != this.queryInstance) {
+      return;
+    }
+
+    let resultsAdded = 0;
+    let staleTabs = [];
+    for (let { tab, client } of tabsData) {
+      if (
+        !searchString ||
+        searchString == lazy.UrlbarTokenizer.RESTRICT.OPENPAGE ||
+        re.test(tab.url) ||
+        (tab.title && re.test(tab.title))
+      ) {
+        if (lazy.showRemoteIconsPref) {
+          if (!tab.icon) {
+            // It's rare that Sync supplies the icon for the page. If it does, it is a
+            // string URL.
+            tab.icon = UrlbarUtils.getIconForUrl(tab.url);
+          } else {
+            tab.icon = lazy.PlacesUtils.favicons.getFaviconLinkForIcon(
+              Services.io.newURI(tab.icon)
+            ).spec;
+          }
+        }
+
+        let result = new lazy.UrlbarResult(
+          UrlbarUtils.RESULT_TYPE.REMOTE_TAB,
+          UrlbarUtils.RESULT_SOURCE.TABS,
+          ...lazy.UrlbarResult.payloadAndSimpleHighlights(queryContext.tokens, {
+            url: [tab.url, UrlbarUtils.HIGHLIGHT.TYPED],
+            title: [tab.title, UrlbarUtils.HIGHLIGHT.TYPED],
+            device: client.name,
+            icon: lazy.showRemoteIconsPref ? tab.icon : "",
+            lastUsed: (tab.lastUsed || 0) * 1000,
+          })
+        );
+
+        // We want to return the most relevant remote tabs and thus the most
+        // recent ones. While SyncedTabs.jsm returns tabs that are sorted by
+        // most recent client, then most recent tab, we can do better. For
+        // example, the most recent client might have one recent tab and then
+        // many very stale tabs. Those very stale tabs will push out more recent
+        // tabs from staler clients. This provider first returns tabs from the
+        // last 72 hours, sorted by client recency. Then, it adds remaining
+        // tabs. We are not concerned about filling the remote tabs group with
+        // stale tabs, because the muxer ensures remote tabs flex with other
+        // results. It will only show the stale tabs if it has nothing else
+        // to show.
+        if (
+          tab.lastUsed <=
+          (Date.now() - RECENT_REMOTE_TAB_THRESHOLD_MS) / 1000
+        ) {
+          staleTabs.push(result);
+        } else {
+          addCallback(this, result);
+          resultsAdded++;
+        }
+      }
+
+      if (resultsAdded == queryContext.maxResults) {
+        break;
+      }
+    }
+
+    while (staleTabs.length && resultsAdded < queryContext.maxResults) {
+      addCallback(this, staleTabs.shift());
+      resultsAdded++;
+    }
+  }
+
+  /**
+   * Build the in-memory structure we use.
+   */
+  async buildItems() {
+    // This is sorted by most recent client, most recent tab.
+    let tabsData = [];
+    // If Sync isn't initialized (either due to lag at startup or due to no user
+    // being signed in), don't reach in to Weave.Service as that may initialize
+    // Sync unnecessarily - we'll get an observer notification later when it
+    // becomes ready and has synced a list of tabs.
+    if (lazy.weaveXPCService.ready) {
+      let clients = await lazy.SyncedTabs.getTabClients();
+      lazy.SyncedTabs.sortTabClientsByLastUsed(clients);
+      for (let client of clients) {
+        for (let tab of client.tabs) {
+          tabsData.push({ tab, client });
+        }
+      }
+    }
+    return tabsData;
+  }
+
+  /**
+   * Ensure the cache is good.
+   */
+  async ensureCache() {
+    if (!_cache) {
+      _cache = await this.buildItems();
+    }
+    return _cache;
+  }
+
+  observe(subject, topic, data) {
+    switch (topic) {
+      case "weave:engine:sync:finish":
+        if (data == "tabs") {
+          // The tabs engine just finished syncing, so may have a different list
+          // of tabs then we previously cached.
+          _cache = null;
+        }
+        break;
+
+      case "weave:service:start-over":
+        // Sync is being reset due to the user disconnecting - we must invalidate
+        // the cache so we don't supply tabs from a different user.
+        _cache = null;
+        break;
+
+      default:
+        break;
+    }
+  }
+}
+
+export var UrlbarProviderRemoteTabs = new ProviderRemoteTabs();