Merge pull request #348 from matrix-org/rav/device_list_stream

Use the device change notifications interface

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 = {};
+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',
+        );
+    }
+    opts = opts || {};
 
-    for (let i = 0; i < userIds.length; ++i) {
-        downloadQuery[userIds[i]] = {};
+    const content = {
+        device_keys: {},
+    };
+    if ('token' in opts) {
+        content.token = opts.token;
     }
-    const content = {device_keys: downloadQuery};
+    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,
     );
 };
@@ -1067,6 +1082,28 @@ MatrixBaseApis.prototype.claimOneTimeKeys = function(devices, key_algorithm) {
     );
 };
 
+/**
+ * Ask the server for a list of users who have changed their device lists
+ * between a pair of sync tokens
+ *
+ * @param {string} oldToken
+ * @param {string} newToken
+ *
+ * @return {module:client.Promise} Resolves: result object. Rejects: with
+ *     an error response ({@link module:http-api.MatrixError}).
+ */
+MatrixBaseApis.prototype.getKeyChanges = function(oldToken, newToken) {
+    const qps = {
+        from: oldToken,
+        to: newToken,
+    };
+
+    return this._http.authedRequestWithPrefix(
+        undefined, "GET", "/keys/changes", qps, undefined,
+        httpApi.PREFIX_UNSTABLE,
+    );
+};
+
 
 // Identity Server Operations
 // ==========================

src/client.js

@@ -158,6 +158,7 @@ function MatrixClient(opts) {
             this, this,
             opts.sessionStore,
             userId, this.deviceId,
+            this.store,
         );
 
         this.olmVersion = Crypto.getOlmVersion();
@@ -2665,8 +2666,6 @@ MatrixClient.prototype.startClient = function(opts) {
         };
     }
 
-    this._clientOpts = opts;
-
     if (this._crypto) {
         this._crypto.uploadKeys(5).done();
         const tenMinutes = 1000 * 60 * 10;
@@ -2684,6 +2683,13 @@ 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();
 };
@@ -3067,12 +3073,26 @@ 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 || {};
 
@@ -319,6 +326,10 @@ export default class DeviceList {
                 this._sessionStore.storeEndToEndDevicesForUser(
                     userId, storage,
                 );
+
+                if (token) {
+                    this._sessionStore.storeEndToEndDeviceSyncToken(token);
+                }
             }
         });
     }