diff options
Diffstat (limited to 'synapse/storage/databases')
| -rw-r--r-- | synapse/storage/databases/main/devices.py | 94 |
1 files changed, 78 insertions, 16 deletions
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py index 324bd5f879..bc7e876047 100644 --- a/synapse/storage/databases/main/devices.py +++ b/synapse/storage/databases/main/devices.py @@ -191,7 +191,7 @@ class DeviceWorkerStore(SQLBaseStore): @trace async def get_device_updates_by_remote( self, destination: str, from_stream_id: int, limit: int - ) -> Tuple[int, List[Tuple[str, dict]]]: + ) -> Tuple[int, List[Tuple[str, JsonDict]]]: """Get a stream of device updates to send to the given remote server. Args: @@ -200,9 +200,10 @@ class DeviceWorkerStore(SQLBaseStore): limit: Maximum number of device updates to return Returns: - A mapping from the current stream id (ie, the stream id of the last - update included in the response), and the list of updates, where - each update is a pair of EDU type and EDU contents. + - The current stream id (i.e. the stream id of the last update included + in the response); and + - The list of updates, where each update is a pair of EDU type and + EDU contents. """ now_stream_id = self.get_device_stream_token() @@ -221,6 +222,9 @@ class DeviceWorkerStore(SQLBaseStore): limit, ) + # We need to ensure `updates` doesn't grow too big. + # Currently: `len(updates) <= limit`. + # Return an empty list if there are no updates if not updates: return now_stream_id, [] @@ -277,16 +281,43 @@ class DeviceWorkerStore(SQLBaseStore): query_map = {} cross_signing_keys_by_user = {} for user_id, device_id, update_stream_id, update_context in updates: - if ( + # Calculate the remaining length budget. + # Note that, for now, each entry in `cross_signing_keys_by_user` + # gives rise to two device updates in the result, so those cost twice + # as much (and are the whole reason we need to separately calculate + # the budget; we know len(updates) <= limit otherwise!) + # N.B. len() on dicts is cheap since they store their size. + remaining_length_budget = limit - ( + len(query_map) + 2 * len(cross_signing_keys_by_user) + ) + assert remaining_length_budget >= 0 + + is_master_key_update = ( user_id in master_key_by_user and device_id == master_key_by_user[user_id]["device_id"] - ): - result = cross_signing_keys_by_user.setdefault(user_id, {}) - result["master_key"] = master_key_by_user[user_id]["key_info"] - elif ( + ) + is_self_signing_key_update = ( user_id in self_signing_key_by_user and device_id == self_signing_key_by_user[user_id]["device_id"] + ) + + is_cross_signing_key_update = ( + is_master_key_update or is_self_signing_key_update + ) + + if ( + is_cross_signing_key_update + and user_id not in cross_signing_keys_by_user ): + # This will give rise to 2 device updates. + # If we don't have the budget, stop here! + if remaining_length_budget < 2: + break + + if is_master_key_update: + result = cross_signing_keys_by_user.setdefault(user_id, {}) + result["master_key"] = master_key_by_user[user_id]["key_info"] + elif is_self_signing_key_update: result = cross_signing_keys_by_user.setdefault(user_id, {}) result["self_signing_key"] = self_signing_key_by_user[user_id][ "key_info" @@ -294,23 +325,44 @@ class DeviceWorkerStore(SQLBaseStore): else: key = (user_id, device_id) + if key not in query_map and remaining_length_budget < 1: + # We don't have space for a new entry + break + previous_update_stream_id, _ = query_map.get(key, (0, None)) if update_stream_id > previous_update_stream_id: + # FIXME If this overwrites an older update, this discards the + # previous OpenTracing context. + # It might make it harder to track down issues using OpenTracing. + # If there's a good reason why it doesn't matter, a comment here + # about that would not hurt. query_map[key] = (update_stream_id, update_context) + # As this update has been added to the response, advance the stream + # position. last_processed_stream_id = update_stream_id + # In the worst case scenario, each update is for a distinct user and is + # added either to the query_map or to cross_signing_keys_by_user, + # but not both: + # len(query_map) + len(cross_signing_keys_by_user) <= len(updates) here, + # so len(query_map) + len(cross_signing_keys_by_user) <= limit. + results = await self._get_device_update_edus_by_remote( destination, from_stream_id, query_map ) - # add the updated cross-signing keys to the results list + # len(results) <= len(query_map) here, + # so len(results) + len(cross_signing_keys_by_user) <= limit. + + # Add the updated cross-signing keys to the results list for user_id, result in cross_signing_keys_by_user.items(): result["user_id"] = user_id results.append(("m.signing_key_update", result)) # also send the unstable version # FIXME: remove this when enough servers have upgraded + # and remove the length budgeting above. results.append(("org.matrix.signing_key_update", result)) return last_processed_stream_id, results @@ -322,7 +374,7 @@ class DeviceWorkerStore(SQLBaseStore): from_stream_id: int, now_stream_id: int, limit: int, - ): + ) -> List[Tuple[str, str, int, Optional[str]]]: """Return device update information for a given remote destination Args: @@ -333,7 +385,11 @@ class DeviceWorkerStore(SQLBaseStore): limit: Maximum number of device updates to return Returns: - List: List of device updates + List: List of device update tuples: + - user_id + - device_id + - stream_id + - opentracing_context """ # get the list of device updates that need to be sent sql = """ @@ -357,15 +413,21 @@ class DeviceWorkerStore(SQLBaseStore): Args: destination: The host the device updates are intended for from_stream_id: The minimum stream_id to filter updates by, exclusive - query_map (Dict[(str, str): (int, str|None)]): Dictionary mapping - user_id/device_id to update stream_id and the relevant json-encoded - opentracing context + query_map: Dictionary mapping (user_id, device_id) to + (update stream_id, the relevant json-encoded opentracing context) Returns: - List of objects representing an device update EDU + List of objects representing a device update EDU. + + Postconditions: + The returned list has a length not exceeding that of the query_map: + len(result) <= len(query_map) """ devices = ( await self.get_e2e_device_keys_and_signatures( + # Because these are (user_id, device_id) tuples with all + # device_ids not being None, the returned list's length will not + # exceed that of query_map. query_map.keys(), include_all_devices=True, include_deleted_devices=True, |