Merge pull request #4796 from matrix-org/erikj/factor_out_e2e_keys

 Allow /keys/{changes,query} API to run on worker

1 files changed, 338 insertions, 337 deletions

diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index ecdab34e7d..e716dc1437 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -22,11 +22,10 @@ from twisted.internet import defer
 
 from synapse.api.errors import StoreError
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import Cache, SQLBaseStore, db_to_json
 from synapse.storage.background_updates import BackgroundUpdateStore
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
 
-from ._base import Cache, db_to_json
-
 logger = logging.getLogger(__name__)
 
 DROP_DEVICE_LIST_STREAMS_NON_UNIQUE_INDEXES = (
@@ -34,7 +33,343 @@ DROP_DEVICE_LIST_STREAMS_NON_UNIQUE_INDEXES = (
 )
 
 
-class DeviceStore(BackgroundUpdateStore):
+class DeviceWorkerStore(SQLBaseStore):
+    def get_device(self, user_id, device_id):
+        """Retrieve a device.
+
+        Args:
+            user_id (str): The ID of the user which owns the device
+            device_id (str): The ID of the device to retrieve
+        Returns:
+            defer.Deferred for a dict containing the device information
+        Raises:
+            StoreError: if the device is not found
+        """
+        return self._simple_select_one(
+            table="devices",
+            keyvalues={"user_id": user_id, "device_id": device_id},
+            retcols=("user_id", "device_id", "display_name"),
+            desc="get_device",
+        )
+
+    @defer.inlineCallbacks
+    def get_devices_by_user(self, user_id):
+        """Retrieve all of a user's registered devices.
+
+        Args:
+            user_id (str):
+        Returns:
+            defer.Deferred: resolves to a dict from device_id to a dict
+            containing "device_id", "user_id" and "display_name" for each
+            device.
+        """
+        devices = yield self._simple_select_list(
+            table="devices",
+            keyvalues={"user_id": user_id},
+            retcols=("user_id", "device_id", "display_name"),
+            desc="get_devices_by_user"
+        )
+
+        defer.returnValue({d["device_id"]: d for d in devices})
+
+    def get_devices_by_remote(self, destination, from_stream_id):
+        """Get stream of updates to send to remote servers
+
+        Returns:
+            (int, list[dict]): current stream id and list of updates
+        """
+        now_stream_id = self._device_list_id_gen.get_current_token()
+
+        has_changed = self._device_list_federation_stream_cache.has_entity_changed(
+            destination, int(from_stream_id)
+        )
+        if not has_changed:
+            return (now_stream_id, [])
+
+        return self.runInteraction(
+            "get_devices_by_remote", self._get_devices_by_remote_txn,
+            destination, from_stream_id, now_stream_id,
+        )
+
+    def _get_devices_by_remote_txn(self, txn, destination, from_stream_id,
+                                   now_stream_id):
+        sql = """
+            SELECT user_id, device_id, max(stream_id) FROM device_lists_outbound_pokes
+            WHERE destination = ? AND ? < stream_id AND stream_id <= ? AND sent = ?
+            GROUP BY user_id, device_id
+            LIMIT 20
+        """
+        txn.execute(
+            sql, (destination, from_stream_id, now_stream_id, False)
+        )
+
+        # maps (user_id, device_id) -> stream_id
+        query_map = {(r[0], r[1]): r[2] for r in txn}
+        if not query_map:
+            return (now_stream_id, [])
+
+        if len(query_map) >= 20:
+            now_stream_id = max(stream_id for stream_id in itervalues(query_map))
+
+        devices = self._get_e2e_device_keys_txn(
+            txn, query_map.keys(), include_all_devices=True, include_deleted_devices=True
+        )
+
+        prev_sent_id_sql = """
+            SELECT coalesce(max(stream_id), 0) as stream_id
+            FROM device_lists_outbound_last_success
+            WHERE destination = ? AND user_id = ? AND stream_id <= ?
+        """
+
+        results = []
+        for user_id, user_devices in iteritems(devices):
+            # The prev_id for the first row is always the last row before
+            # `from_stream_id`
+            txn.execute(prev_sent_id_sql, (destination, user_id, from_stream_id))
+            rows = txn.fetchall()
+            prev_id = rows[0][0]
+            for device_id, device in iteritems(user_devices):
+                stream_id = query_map[(user_id, device_id)]
+                result = {
+                    "user_id": user_id,
+                    "device_id": device_id,
+                    "prev_id": [prev_id] if prev_id else [],
+                    "stream_id": stream_id,
+                }
+
+                prev_id = stream_id
+
+                if device is not None:
+                    key_json = device.get("key_json", None)
+                    if key_json:
+                        result["keys"] = db_to_json(key_json)
+                    device_display_name = device.get("device_display_name", None)
+                    if device_display_name:
+                        result["device_display_name"] = device_display_name
+                else:
+                    result["deleted"] = True
+
+                results.append(result)
+
+        return (now_stream_id, results)
+
+    def mark_as_sent_devices_by_remote(self, destination, stream_id):
+        """Mark that updates have successfully been sent to the destination.
+        """
+        return self.runInteraction(
+            "mark_as_sent_devices_by_remote", self._mark_as_sent_devices_by_remote_txn,
+            destination, stream_id,
+        )
+
+    def _mark_as_sent_devices_by_remote_txn(self, txn, destination, stream_id):
+        # We update the device_lists_outbound_last_success with the successfully
+        # poked users. We do the join to see which users need to be inserted and
+        # which updated.
+        sql = """
+            SELECT user_id, coalesce(max(o.stream_id), 0), (max(s.stream_id) IS NOT NULL)
+            FROM device_lists_outbound_pokes as o
+            LEFT JOIN device_lists_outbound_last_success as s
+                USING (destination, user_id)
+            WHERE destination = ? AND o.stream_id <= ?
+            GROUP BY user_id
+        """
+        txn.execute(sql, (destination, stream_id,))
+        rows = txn.fetchall()
+
+        sql = """
+            UPDATE device_lists_outbound_last_success
+            SET stream_id = ?
+            WHERE destination = ? AND user_id = ?
+        """
+        txn.executemany(
+            sql, ((row[1], destination, row[0],) for row in rows if row[2])
+        )
+
+        sql = """
+            INSERT INTO device_lists_outbound_last_success
+            (destination, user_id, stream_id) VALUES (?, ?, ?)
+        """
+        txn.executemany(
+            sql, ((destination, row[0], row[1],) for row in rows if not row[2])
+        )
+
+        # Delete all sent outbound pokes
+        sql = """
+            DELETE FROM device_lists_outbound_pokes
+            WHERE destination = ? AND stream_id <= ?
+        """
+        txn.execute(sql, (destination, stream_id,))
+
+    def get_device_stream_token(self):
+        return self._device_list_id_gen.get_current_token()
+
+    @defer.inlineCallbacks
+    def get_user_devices_from_cache(self, query_list):
+        """Get the devices (and keys if any) for remote users from the cache.
+
+        Args:
+            query_list(list): List of (user_id, device_ids), if device_ids is
+                falsey then return all device ids for that user.
+
+        Returns:
+            (user_ids_not_in_cache, results_map), where user_ids_not_in_cache is
+            a set of user_ids and results_map is a mapping of
+            user_id -> device_id -> device_info
+        """
+        user_ids = set(user_id for user_id, _ in query_list)
+        user_map = yield self.get_device_list_last_stream_id_for_remotes(list(user_ids))
+        user_ids_in_cache = set(
+            user_id for user_id, stream_id in user_map.items() if stream_id
+        )
+        user_ids_not_in_cache = user_ids - user_ids_in_cache
+
+        results = {}
+        for user_id, device_id in query_list:
+            if user_id not in user_ids_in_cache:
+                continue
+
+            if device_id:
+                device = yield self._get_cached_user_device(user_id, device_id)
+                results.setdefault(user_id, {})[device_id] = device
+            else:
+                results[user_id] = yield self._get_cached_devices_for_user(user_id)
+
+        defer.returnValue((user_ids_not_in_cache, results))
+
+    @cachedInlineCallbacks(num_args=2, tree=True)
+    def _get_cached_user_device(self, user_id, device_id):
+        content = yield self._simple_select_one_onecol(
+            table="device_lists_remote_cache",
+            keyvalues={
+                "user_id": user_id,
+                "device_id": device_id,
+            },
+            retcol="content",
+            desc="_get_cached_user_device",
+        )
+        defer.returnValue(db_to_json(content))
+
+    @cachedInlineCallbacks()
+    def _get_cached_devices_for_user(self, user_id):
+        devices = yield self._simple_select_list(
+            table="device_lists_remote_cache",
+            keyvalues={
+                "user_id": user_id,
+            },
+            retcols=("device_id", "content"),
+            desc="_get_cached_devices_for_user",
+        )
+        defer.returnValue({
+            device["device_id"]: db_to_json(device["content"])
+            for device in devices
+        })
+
+    def get_devices_with_keys_by_user(self, user_id):
+        """Get all devices (with any device keys) for a user
+
+        Returns:
+            (stream_id, devices)
+        """
+        return self.runInteraction(
+            "get_devices_with_keys_by_user",
+            self._get_devices_with_keys_by_user_txn, user_id,
+        )
+
+    def _get_devices_with_keys_by_user_txn(self, txn, user_id):
+        now_stream_id = self._device_list_id_gen.get_current_token()
+
+        devices = self._get_e2e_device_keys_txn(
+            txn, [(user_id, None)], include_all_devices=True
+        )
+
+        if devices:
+            user_devices = devices[user_id]
+            results = []
+            for device_id, device in iteritems(user_devices):
+                result = {
+                    "device_id": device_id,
+                }
+
+                key_json = device.get("key_json", None)
+                if key_json:
+                    result["keys"] = db_to_json(key_json)
+                device_display_name = device.get("device_display_name", None)
+                if device_display_name:
+                    result["device_display_name"] = device_display_name
+
+                results.append(result)
+
+            return now_stream_id, results
+
+        return now_stream_id, []
+
+    @defer.inlineCallbacks
+    def get_user_whose_devices_changed(self, from_key):
+        """Get set of users whose devices have changed since `from_key`.
+        """
+        from_key = int(from_key)
+        changed = self._device_list_stream_cache.get_all_entities_changed(from_key)
+        if changed is not None:
+            defer.returnValue(set(changed))
+
+        sql = """
+            SELECT DISTINCT user_id FROM device_lists_stream WHERE stream_id > ?
+        """
+        rows = yield self._execute("get_user_whose_devices_changed", None, sql, from_key)
+        defer.returnValue(set(row[0] for row in rows))
+
+    def get_all_device_list_changes_for_remotes(self, from_key, to_key):
+        """Return a list of `(stream_id, user_id, destination)` which is the
+        combined list of changes to devices, and which destinations need to be
+        poked. `destination` may be None if no destinations need to be poked.
+        """
+        # We do a group by here as there can be a large number of duplicate
+        # entries, since we throw away device IDs.
+        sql = """
+            SELECT MAX(stream_id) AS stream_id, user_id, destination
+            FROM device_lists_stream
+            LEFT JOIN device_lists_outbound_pokes USING (stream_id, user_id, device_id)
+            WHERE ? < stream_id AND stream_id <= ?
+            GROUP BY user_id, destination
+        """
+        return self._execute(
+            "get_all_device_list_changes_for_remotes", None,
+            sql, from_key, to_key
+        )
+
+    @cached(max_entries=10000)
+    def get_device_list_last_stream_id_for_remote(self, user_id):
+        """Get the last stream_id we got for a user. May be None if we haven't
+        got any information for them.
+        """
+        return self._simple_select_one_onecol(
+            table="device_lists_remote_extremeties",
+            keyvalues={"user_id": user_id},
+            retcol="stream_id",
+            desc="get_device_list_last_stream_id_for_remote",
+            allow_none=True,
+        )
+
+    @cachedList(cached_method_name="get_device_list_last_stream_id_for_remote",
+                list_name="user_ids", inlineCallbacks=True)
+    def get_device_list_last_stream_id_for_remotes(self, user_ids):
+        rows = yield self._simple_select_many_batch(
+            table="device_lists_remote_extremeties",
+            column="user_id",
+            iterable=user_ids,
+            retcols=("user_id", "stream_id",),
+            desc="get_device_list_last_stream_id_for_remotes",
+        )
+
+        results = {user_id: None for user_id in user_ids}
+        results.update({
+            row["user_id"]: row["stream_id"] for row in rows
+        })
+
+        defer.returnValue(results)
+
+
+class DeviceStore(DeviceWorkerStore, BackgroundUpdateStore):
     def __init__(self, db_conn, hs):
         super(DeviceStore, self).__init__(db_conn, hs)
 
@@ -121,24 +456,6 @@ class DeviceStore(BackgroundUpdateStore):
                          initial_device_display_name, e)
             raise StoreError(500, "Problem storing device.")
 
-    def get_device(self, user_id, device_id):
-        """Retrieve a device.
-
-        Args:
-            user_id (str): The ID of the user which owns the device
-            device_id (str): The ID of the device to retrieve
-        Returns:
-            defer.Deferred for a dict containing the device information
-        Raises:
-            StoreError: if the device is not found
-        """
-        return self._simple_select_one(
-            table="devices",
-            keyvalues={"user_id": user_id, "device_id": device_id},
-            retcols=("user_id", "device_id", "display_name"),
-            desc="get_device",
-        )
-
     @defer.inlineCallbacks
     def delete_device(self, user_id, device_id):
         """Delete a device.
@@ -203,57 +520,6 @@ class DeviceStore(BackgroundUpdateStore):
         )
 
     @defer.inlineCallbacks
-    def get_devices_by_user(self, user_id):
-        """Retrieve all of a user's registered devices.
-
-        Args:
-            user_id (str):
-        Returns:
-            defer.Deferred: resolves to a dict from device_id to a dict
-            containing "device_id", "user_id" and "display_name" for each
-            device.
-        """
-        devices = yield self._simple_select_list(
-            table="devices",
-            keyvalues={"user_id": user_id},
-            retcols=("user_id", "device_id", "display_name"),
-            desc="get_devices_by_user"
-        )
-
-        defer.returnValue({d["device_id"]: d for d in devices})
-
-    @cached(max_entries=10000)
-    def get_device_list_last_stream_id_for_remote(self, user_id):
-        """Get the last stream_id we got for a user. May be None if we haven't
-        got any information for them.
-        """
-        return self._simple_select_one_onecol(
-            table="device_lists_remote_extremeties",
-            keyvalues={"user_id": user_id},
-            retcol="stream_id",
-            desc="get_device_list_remote_extremity",
-            allow_none=True,
-        )
-
-    @cachedList(cached_method_name="get_device_list_last_stream_id_for_remote",
-                list_name="user_ids", inlineCallbacks=True)
-    def get_device_list_last_stream_id_for_remotes(self, user_ids):
-        rows = yield self._simple_select_many_batch(
-            table="device_lists_remote_extremeties",
-            column="user_id",
-            iterable=user_ids,
-            retcols=("user_id", "stream_id",),
-            desc="get_user_devices_from_cache",
-        )
-
-        results = {user_id: None for user_id in user_ids}
-        results.update({
-            row["user_id"]: row["stream_id"] for row in rows
-        })
-
-        defer.returnValue(results)
-
-    @defer.inlineCallbacks
     def mark_remote_user_device_list_as_unsubscribed(self, user_id):
         """Mark that we no longer track device lists for remote user.
         """
@@ -405,268 +671,6 @@ class DeviceStore(BackgroundUpdateStore):
             lock=False,
         )
 
-    def get_devices_by_remote(self, destination, from_stream_id):
-        """Get stream of updates to send to remote servers
-
-        Returns:
-            (int, list[dict]): current stream id and list of updates
-        """
-        now_stream_id = self._device_list_id_gen.get_current_token()
-
-        has_changed = self._device_list_federation_stream_cache.has_entity_changed(
-            destination, int(from_stream_id)
-        )
-        if not has_changed:
-            return (now_stream_id, [])
-
-        return self.runInteraction(
-            "get_devices_by_remote", self._get_devices_by_remote_txn,
-            destination, from_stream_id, now_stream_id,
-        )
-
-    def _get_devices_by_remote_txn(self, txn, destination, from_stream_id,
-                                   now_stream_id):
-        sql = """
-            SELECT user_id, device_id, max(stream_id) FROM device_lists_outbound_pokes
-            WHERE destination = ? AND ? < stream_id AND stream_id <= ? AND sent = ?
-            GROUP BY user_id, device_id
-            LIMIT 20
-        """
-        txn.execute(
-            sql, (destination, from_stream_id, now_stream_id, False)
-        )
-
-        # maps (user_id, device_id) -> stream_id
-        query_map = {(r[0], r[1]): r[2] for r in txn}
-        if not query_map:
-            return (now_stream_id, [])
-
-        if len(query_map) >= 20:
-            now_stream_id = max(stream_id for stream_id in itervalues(query_map))
-
-        devices = self._get_e2e_device_keys_txn(
-            txn, query_map.keys(), include_all_devices=True, include_deleted_devices=True
-        )
-
-        prev_sent_id_sql = """
-            SELECT coalesce(max(stream_id), 0) as stream_id
-            FROM device_lists_outbound_last_success
-            WHERE destination = ? AND user_id = ? AND stream_id <= ?
-        """
-
-        results = []
-        for user_id, user_devices in iteritems(devices):
-            # The prev_id for the first row is always the last row before
-            # `from_stream_id`
-            txn.execute(prev_sent_id_sql, (destination, user_id, from_stream_id))
-            rows = txn.fetchall()
-            prev_id = rows[0][0]
-            for device_id, device in iteritems(user_devices):
-                stream_id = query_map[(user_id, device_id)]
-                result = {
-                    "user_id": user_id,
-                    "device_id": device_id,
-                    "prev_id": [prev_id] if prev_id else [],
-                    "stream_id": stream_id,
-                }
-
-                prev_id = stream_id
-
-                if device is not None:
-                    key_json = device.get("key_json", None)
-                    if key_json:
-                        result["keys"] = db_to_json(key_json)
-                    device_display_name = device.get("device_display_name", None)
-                    if device_display_name:
-                        result["device_display_name"] = device_display_name
-                else:
-                    result["deleted"] = True
-
-                results.append(result)
-
-        return (now_stream_id, results)
-
-    @defer.inlineCallbacks
-    def get_user_devices_from_cache(self, query_list):
-        """Get the devices (and keys if any) for remote users from the cache.
-
-        Args:
-            query_list(list): List of (user_id, device_ids), if device_ids is
-                falsey then return all device ids for that user.
-
-        Returns:
-            (user_ids_not_in_cache, results_map), where user_ids_not_in_cache is
-            a set of user_ids and results_map is a mapping of
-            user_id -> device_id -> device_info
-        """
-        user_ids = set(user_id for user_id, _ in query_list)
-        user_map = yield self.get_device_list_last_stream_id_for_remotes(list(user_ids))
-        user_ids_in_cache = set(
-            user_id for user_id, stream_id in user_map.items() if stream_id
-        )
-        user_ids_not_in_cache = user_ids - user_ids_in_cache
-
-        results = {}
-        for user_id, device_id in query_list:
-            if user_id not in user_ids_in_cache:
-                continue
-
-            if device_id:
-                device = yield self._get_cached_user_device(user_id, device_id)
-                results.setdefault(user_id, {})[device_id] = device
-            else:
-                results[user_id] = yield self._get_cached_devices_for_user(user_id)
-
-        defer.returnValue((user_ids_not_in_cache, results))
-
-    @cachedInlineCallbacks(num_args=2, tree=True)
-    def _get_cached_user_device(self, user_id, device_id):
-        content = yield self._simple_select_one_onecol(
-            table="device_lists_remote_cache",
-            keyvalues={
-                "user_id": user_id,
-                "device_id": device_id,
-            },
-            retcol="content",
-            desc="_get_cached_user_device",
-        )
-        defer.returnValue(db_to_json(content))
-
-    @cachedInlineCallbacks()
-    def _get_cached_devices_for_user(self, user_id):
-        devices = yield self._simple_select_list(
-            table="device_lists_remote_cache",
-            keyvalues={
-                "user_id": user_id,
-            },
-            retcols=("device_id", "content"),
-            desc="_get_cached_devices_for_user",
-        )
-        defer.returnValue({
-            device["device_id"]: db_to_json(device["content"])
-            for device in devices
-        })
-
-    def get_devices_with_keys_by_user(self, user_id):
-        """Get all devices (with any device keys) for a user
-
-        Returns:
-            (stream_id, devices)
-        """
-        return self.runInteraction(
-            "get_devices_with_keys_by_user",
-            self._get_devices_with_keys_by_user_txn, user_id,
-        )
-
-    def _get_devices_with_keys_by_user_txn(self, txn, user_id):
-        now_stream_id = self._device_list_id_gen.get_current_token()
-
-        devices = self._get_e2e_device_keys_txn(
-            txn, [(user_id, None)], include_all_devices=True
-        )
-
-        if devices:
-            user_devices = devices[user_id]
-            results = []
-            for device_id, device in iteritems(user_devices):
-                result = {
-                    "device_id": device_id,
-                }
-
-                key_json = device.get("key_json", None)
-                if key_json:
-                    result["keys"] = db_to_json(key_json)
-                device_display_name = device.get("device_display_name", None)
-                if device_display_name:
-                    result["device_display_name"] = device_display_name
-
-                results.append(result)
-
-            return now_stream_id, results
-
-        return now_stream_id, []
-
-    def mark_as_sent_devices_by_remote(self, destination, stream_id):
-        """Mark that updates have successfully been sent to the destination.
-        """
-        return self.runInteraction(
-            "mark_as_sent_devices_by_remote", self._mark_as_sent_devices_by_remote_txn,
-            destination, stream_id,
-        )
-
-    def _mark_as_sent_devices_by_remote_txn(self, txn, destination, stream_id):
-        # We update the device_lists_outbound_last_success with the successfully
-        # poked users. We do the join to see which users need to be inserted and
-        # which updated.
-        sql = """
-            SELECT user_id, coalesce(max(o.stream_id), 0), (max(s.stream_id) IS NOT NULL)
-            FROM device_lists_outbound_pokes as o
-            LEFT JOIN device_lists_outbound_last_success as s
-                USING (destination, user_id)
-            WHERE destination = ? AND o.stream_id <= ?
-            GROUP BY user_id
-        """
-        txn.execute(sql, (destination, stream_id,))
-        rows = txn.fetchall()
-
-        sql = """
-            UPDATE device_lists_outbound_last_success
-            SET stream_id = ?
-            WHERE destination = ? AND user_id = ?
-        """
-        txn.executemany(
-            sql, ((row[1], destination, row[0],) for row in rows if row[2])
-        )
-
-        sql = """
-            INSERT INTO device_lists_outbound_last_success
-            (destination, user_id, stream_id) VALUES (?, ?, ?)
-        """
-        txn.executemany(
-            sql, ((destination, row[0], row[1],) for row in rows if not row[2])
-        )
-
-        # Delete all sent outbound pokes
-        sql = """
-            DELETE FROM device_lists_outbound_pokes
-            WHERE destination = ? AND stream_id <= ?
-        """
-        txn.execute(sql, (destination, stream_id,))
-
-    @defer.inlineCallbacks
-    def get_user_whose_devices_changed(self, from_key):
-        """Get set of users whose devices have changed since `from_key`.
-        """
-        from_key = int(from_key)
-        changed = self._device_list_stream_cache.get_all_entities_changed(from_key)
-        if changed is not None:
-            defer.returnValue(set(changed))
-
-        sql = """
-            SELECT DISTINCT user_id FROM device_lists_stream WHERE stream_id > ?
-        """
-        rows = yield self._execute("get_user_whose_devices_changed", None, sql, from_key)
-        defer.returnValue(set(row[0] for row in rows))
-
-    def get_all_device_list_changes_for_remotes(self, from_key, to_key):
-        """Return a list of `(stream_id, user_id, destination)` which is the
-        combined list of changes to devices, and which destinations need to be
-        poked. `destination` may be None if no destinations need to be poked.
-        """
-        # We do a group by here as there can be a large number of duplicate
-        # entries, since we throw away device IDs.
-        sql = """
-            SELECT MAX(stream_id) AS stream_id, user_id, destination
-            FROM device_lists_stream
-            LEFT JOIN device_lists_outbound_pokes USING (stream_id, user_id, device_id)
-            WHERE ? < stream_id AND stream_id <= ?
-            GROUP BY user_id, destination
-        """
-        return self._execute(
-            "get_all_device_list_changes_for_remotes", None,
-            sql, from_key, to_key
-        )
-
     @defer.inlineCallbacks
     def add_device_change_to_streams(self, user_id, device_ids, hosts):
         """Persist that a user's devices have been updated, and which hosts
@@ -732,9 +736,6 @@ class DeviceStore(BackgroundUpdateStore):
             ]
         )
 
-    def get_device_stream_token(self):
-        return self._device_list_id_gen.get_current_token()
-
     def _prune_old_outbound_device_pokes(self):
         """Delete old entries out of the device_lists_outbound_pokes to ensure
         that we don't fill up due to dead servers. We keep one entry per