Handle device change notifications from /sync

When we get a notification from /sync that a user has updated their device
list, mark the list outdated, and then fire off a device query.

src/base-apis.js

@@ -1018,20 +1018,35 @@ MatrixBaseApis.prototype.uploadKeysRequest = function(content, opts, callback) {
  *
  * @param {string[]} userIds  list of users to get keys for
  *
- * @param {module:client.callback=} callback
+ * @param {Object=} opts
+ *
+ * @param {string=} opts.token   sync token to pass in the query request, to help
+ *   the HS give the most recent results
  *
  * @return {module:client.Promise} Resolves: result object. Rejects: with
  *     an error response ({@link module:http-api.MatrixError}).
  */
-MatrixBaseApis.prototype.downloadKeysForUsers = function(userIds, callback) {
-    const downloadQuery = {};
-
-    for (let i = 0; i < userIds.length; ++i) {
-        downloadQuery[userIds[i]] = {};
+MatrixBaseApis.prototype.downloadKeysForUsers = function(userIds, opts) {
+    if (utils.isFunction(opts)) {
+        // opts used to be 'callback'.
+        throw new Error(
+            'downloadKeysForUsers no longer accepts a callback parameter',
+        );
     }
-    const content = {device_keys: downloadQuery};
+    opts = opts || {};
+
+    const content = {
+        device_keys: {},
+    };
+    if ('token' in opts) {
+        content.token = opts.token;
+    }
+    userIds.forEach((u) => {
+        content.device_keys[u] = {};
+    });
+
     return this._http.authedRequestWithPrefix(
-        callback, "POST", "/keys/query", undefined, content,
+        undefined, "POST", "/keys/query", undefined, content,
         httpApi.PREFIX_UNSTABLE,
     );
 };

src/client.js

@@ -2638,8 +2638,6 @@ MatrixClient.prototype.startClient = function(opts) {
         };
     }
 
-    this._clientOpts = opts;
-
     if (this._crypto) {
         this._crypto.uploadKeys(5).done();
         const tenMinutes = 1000 * 60 * 10;
@@ -2657,6 +2655,13 @@ MatrixClient.prototype.startClient = function(opts) {
         console.error("Still have sync object whilst not running: stopping old one");
         this._syncApi.stop();
     }
+
+    // shallow-copy the opts dict before modifying and storing it
+    opts = Object.assign({}, opts);
+
+    opts.crypto = this._crypto;
+    this._clientOpts = opts;
+
     this._syncApi = new SyncApi(this, opts);
     this._syncApi.sync();
 };
@@ -3040,12 +3045,26 @@ module.exports.CRYPTO_ENABLED = CRYPTO_ENABLED;
  * </ul>
  *
  * @event module:client~MatrixClient#"sync"
+ *
  * @param {string} state An enum representing the syncing state. One of "PREPARED",
  * "SYNCING", "ERROR", "STOPPED".
+ *
  * @param {?string} prevState An enum representing the previous syncing state.
  * One of "PREPARED", "SYNCING", "ERROR", "STOPPED" <b>or null</b>.
+ *
  * @param {?Object} data Data about this transition.
+ *
  * @param {MatrixError} data.err The matrix error if <code>state=ERROR</code>.
+ *
+ * @param {String} data.oldSyncToken The 'since' token passed to /sync.
+ *    <code>null</code> for the first successful sync since this client was
+ *    started. Only present if <code>state=PREPARED</code> or
+ *    <code>state=SYNCING</code>.
+ *
+ * @param {String} data.nextSyncToken The 'next_batch' result from /sync, which
+ *    will become the 'since' token for the next call to /sync. Only present if
+ *    <code>state=PREPARED</code> or <code>state=SYNCING</code>.
+ *
  * @example
  * matrixClient.on("sync", function(state, prevState, data) {
  *   switch (state) {

src/crypto/DeviceList.js

@@ -41,6 +41,8 @@ export default class DeviceList {
 
         // userId -> promise
         this._keyDownloadsInProgressByUser = {};
+
+        this.lastKnownSyncToken = null;
     }
 
     /**
@@ -288,8 +290,13 @@ export default class DeviceList {
     _doKeyDownloadForUsers(downloadUsers) {
         console.log('Starting key download for ' + downloadUsers);
 
+        const token = this.lastKnownSyncToken;
+        const opts = {};
+        if (token) {
+            opts.token = token;
+        }
         return this._baseApis.downloadKeysForUsers(
-            downloadUsers,
+            downloadUsers, opts,
         ).then((res) => {
             const dk = res.device_keys || {};
 

src/crypto/index.js

@@ -55,8 +55,6 @@ function Crypto(baseApis, eventEmitter, sessionStore, userId, deviceId) {
     this._userId = userId;
     this._deviceId = deviceId;
 
-    this._initialSyncCompleted = false;
-
     this._olmDevice = new OlmDevice(sessionStore);
     this._deviceList = new DeviceList(baseApis, sessionStore, this._olmDevice);
 
@@ -115,6 +113,9 @@ function _registerEventHandlers(crypto, eventEmitter) {
                 const rooms = eventEmitter.getRooms();
                 crypto._onInitialSyncCompleted(rooms);
             }
+            if (syncState === "SYNCING") {
+                crypto._onSyncCompleted(data);
+            }
         } catch (e) {
             console.error("Error handling sync", e);
         }
@@ -689,6 +690,18 @@ Crypto.prototype.decryptEvent = function(event) {
     alg.decryptEvent(event);
 };
 
+/**
+ * Handle the notification from /sync that a user has updated their device list.
+ *
+ * @param {String} userId
+ */
+Crypto.prototype.userDeviceListChanged = function(userId) {
+    this._deviceList.invalidateUserDeviceList(userId);
+
+    // don't flush the outdated device list yet - we do it once we finish
+    // processing the sync.
+};
+
 /**
  * handle an m.room.encryption event
  *
@@ -716,11 +729,6 @@ Crypto.prototype._onCryptoEvent = function(event) {
  * @param {module:models/room[]} rooms list of rooms the client knows about
  */
 Crypto.prototype._onInitialSyncCompleted = function(rooms) {
-    this._initialSyncCompleted = true;
-
-    // catch up on any m.new_device events which arrived during the initial sync.
-    this._deviceList.refreshOutdatedDeviceLists().done();
-
     if (this._sessionStore.getDeviceAnnounced()) {
         return;
     }
@@ -779,6 +787,12 @@ Crypto.prototype._onInitialSyncCompleted = function(rooms) {
     });
 };
 
+Crypto.prototype._onSyncCompleted = function(syncData) {
+    // catch up on any new devices we got told about during the sync.
+    this._deviceList.lastKnownSyncToken = syncData.nextSyncToken;
+    this._deviceList.refreshOutdatedDeviceLists().done();
+};
+
 /**
  * Handle a key event
  *
@@ -852,12 +866,6 @@ Crypto.prototype._onNewDeviceEvent = function(event) {
     }
 
     this._deviceList.invalidateUserDeviceList(userId);
-
-    // we delay handling these until the intialsync has completed, so that we
-    // can do all of them together.
-    if (this._initialSyncCompleted) {
-        this._deviceList.refreshOutdatedDeviceLists().done();
-    }
 };
 
 

src/sync.js

@@ -58,6 +58,7 @@ function debuglog() {
  * @constructor
  * @param {MatrixClient} client The matrix client instance to use.
  * @param {Object} opts Config options
+ * @param {module:crypto=} opts.crypto Crypto manager
  */
 function SyncApi(client, opts) {
     this.client = client;
@@ -529,13 +530,18 @@ SyncApi.prototype._sync = function(syncOptions) {
         }
 
         // emit synced events
+        const syncEventData = {
+            oldSyncToken: syncToken,
+            nextSyncToken: data.next_batch,
+        };
+
         if (!syncOptions.hasSyncedBefore) {
-            self._updateSyncState("PREPARED");
+            self._updateSyncState("PREPARED", syncEventData);
             syncOptions.hasSyncedBefore = true;
         }
 
         // keep emitting SYNCING -> SYNCING for clients who want to do bulk updates
-        self._updateSyncState("SYNCING");
+        self._updateSyncState("SYNCING", syncEventData);
 
         self._sync(syncOptions);
     }, function(err) {
@@ -584,6 +590,7 @@ SyncApi.prototype._processSyncResponse = function(syncToken, data) {
     //    next_batch: $token,
     //    presence: { events: [] },
     //    account_data: { events: [] },
+    //    device_lists: { changed: ["@user:server", ... ]},
     //    to_device: { events: [] },
     //    rooms: {
     //      invite: {
@@ -859,6 +866,13 @@ SyncApi.prototype._processSyncResponse = function(syncToken, data) {
             client.getNotifTimelineSet().addLiveEvent(event);
         });
     }
+
+    // Handle device list updates
+    if (this.opts.crypto && data.device_lists && data.device_lists.changed) {
+        data.device_lists.changed.forEach((u) => {
+            this.opts.crypto.userDeviceListChanged(u);
+        });
+    }
 };
 
 /**