# -*- coding: utf-8 -*- # Copyright 2014 - 2016 OpenMarket Ltd # Copyright 2017 - 2018 New Vector Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import logging from six import iteritems from twisted.internet import defer from twisted.python.failure import Failure from synapse.api.constants import EventTypes, Membership from synapse.api.errors import SynapseError from synapse.metrics.background_process_metrics import run_as_background_process from synapse.storage.state import StateFilter from synapse.types import RoomStreamToken from synapse.util.async_helpers import ReadWriteLock from synapse.util.logcontext import run_in_background from synapse.util.stringutils import random_string from synapse.visibility import filter_events_for_client logger = logging.getLogger(__name__) class PurgeStatus(object): """Object tracking the status of a purge request This class contains information on the progress of a purge request, for return by get_purge_status. Attributes: status (int): Tracks whether this request has completed. One of STATUS_{ACTIVE,COMPLETE,FAILED} """ STATUS_ACTIVE = 0 STATUS_COMPLETE = 1 STATUS_FAILED = 2 STATUS_TEXT = { STATUS_ACTIVE: "active", STATUS_COMPLETE: "complete", STATUS_FAILED: "failed", } def __init__(self): self.status = PurgeStatus.STATUS_ACTIVE def asdict(self): return { "status": PurgeStatus.STATUS_TEXT[self.status] } class PaginationHandler(object): """Handles pagination and purge history requests. These are in the same handler due to the fact we need to block clients paginating during a purge. """ def __init__(self, hs): self.hs = hs self.auth = hs.get_auth() self.store = hs.get_datastore() self.clock = hs.get_clock() self.pagination_lock = ReadWriteLock() self._purges_in_progress_by_room = set() # map from purge id to PurgeStatus self._purges_by_id = {} self._event_serializer = hs.get_event_client_serializer() self._retention_default_max_lifetime = hs.config.retention_default_max_lifetime if hs.config.retention_enabled: # Run the purge jobs described in the configuration file. for job in hs.config.retention_purge_jobs: self.clock.looping_call( run_as_background_process, job["interval"], "purge_history_for_rooms_in_range", self.purge_history_for_rooms_in_range, job["shortest_max_lifetime"], job["longest_max_lifetime"], ) @defer.inlineCallbacks def purge_history_for_rooms_in_range(self, min_ms, max_ms): """Purge outdated events from rooms within the given retention range. If a default retention policy is defined in the server's configuration and its 'max_lifetime' is within this range, also targets rooms which don't have a retention policy. Args: min_ms (int|None): Duration in milliseconds that define the lower limit of the range to handle (exclusive). If None, it means that the range has no lower limit. max_ms (int|None): Duration in milliseconds that define the upper limit of the range to handle (inclusive). If None, it means that the range has no upper limit. """ # We want the storage layer to to include rooms with no retention policy in its # return value only if a default retention policy is defined in the server's # configuration and that policy's 'max_lifetime' is either lower (or equal) than # max_ms or higher than min_ms (or both). if self._retention_default_max_lifetime is not None: include_null = True if min_ms is not None and min_ms >= self._retention_default_max_lifetime: # The default max_lifetime is lower than (or equal to) min_ms. include_null = False if max_ms is not None and max_ms < self._retention_default_max_lifetime: # The default max_lifetime is higher than max_ms. include_null = False else: include_null = False rooms = yield self.store.get_rooms_for_retention_period_in_range( min_ms, max_ms, include_null ) for room_id, retention_policy in iteritems(rooms): if room_id in self._purges_in_progress_by_room: logger.warning( "[purge] not purging room %s as there's an ongoing purge running" " for this room", room_id, ) continue max_lifetime = retention_policy["max_lifetime"] if max_lifetime is None: # If max_lifetime is None, it means that include_null equals True, # therefore we can safely assume that there is a default policy defined # in the server's configuration. max_lifetime = self._retention_default_max_lifetime # Figure out what token we should start purging at. ts = self.clock.time_msec() - max_lifetime stream_ordering = ( yield self.store.find_first_stream_ordering_after_ts(ts) ) r = ( yield self.store.get_room_event_after_stream_ordering( room_id, stream_ordering, ) ) if not r: logger.warning( "[purge] purging events not possible: No event found " "(ts %i => stream_ordering %i)", ts, stream_ordering, ) continue (stream, topo, _event_id) = r token = "t%d-%d" % (topo, stream) purge_id = random_string(16) self._purges_by_id[purge_id] = PurgeStatus() logger.info( "Starting purging events in room %s (purge_id %s)" % (room_id, purge_id) ) # We want to purge everything, including local events, and to run the purge in # the background so that it's not blocking any other operation apart from # other purges in the same room. run_as_background_process( "_purge_history", self._purge_history, purge_id, room_id, token, True, ) def start_purge_history(self, room_id, token, delete_local_events=False): """Start off a history purge on a room. Args: room_id (str): The room to purge from token (str): topological token to delete events before delete_local_events (bool): True to delete local events as well as remote ones Returns: str: unique ID for this purge transaction. """ if room_id in self._purges_in_progress_by_room: raise SynapseError( 400, "History purge already in progress for %s" % (room_id, ), ) purge_id = random_string(16) # we log the purge_id here so that it can be tied back to the # request id in the log lines. logger.info("[purge] starting purge_id %s", purge_id) self._purges_by_id[purge_id] = PurgeStatus() run_in_background( self._purge_history, purge_id, room_id, token, delete_local_events, ) return purge_id @defer.inlineCallbacks def _purge_history(self, purge_id, room_id, token, delete_local_events): """Carry out a history purge on a room. Args: purge_id (str): The id for this purge room_id (str): The room to purge from token (str): topological token to delete events before delete_local_events (bool): True to delete local events as well as remote ones Returns: Deferred """ self._purges_in_progress_by_room.add(room_id) try: with (yield self.pagination_lock.write(room_id)): yield self.store.purge_history( room_id, token, delete_local_events, ) logger.info("[purge] complete") self._purges_by_id[purge_id].status = PurgeStatus.STATUS_COMPLETE except Exception: f = Failure() logger.error( "[purge] failed", exc_info=(f.type, f.value, f.getTracebackObject()), ) self._purges_by_id[purge_id].status = PurgeStatus.STATUS_FAILED finally: self._purges_in_progress_by_room.discard(room_id) # remove the purge from the list 24 hours after it completes def clear_purge(): del self._purges_by_id[purge_id] self.hs.get_reactor().callLater(24 * 3600, clear_purge) def get_purge_status(self, purge_id): """Get the current status of an active purge Args: purge_id (str): purge_id returned by start_purge_history Returns: PurgeStatus|None """ return self._purges_by_id.get(purge_id) @defer.inlineCallbacks def get_messages(self, requester, room_id=None, pagin_config=None, as_client_event=True, event_filter=None): """Get messages in a room. Args: requester (Requester): The user requesting messages. room_id (str): The room they want messages from. pagin_config (synapse.api.streams.PaginationConfig): The pagination config rules to apply, if any. as_client_event (bool): True to get events in client-server format. event_filter (Filter): Filter to apply to results or None Returns: dict: Pagination API results """ user_id = requester.user.to_string() if pagin_config.from_token: room_token = pagin_config.from_token.room_key else: pagin_config.from_token = ( yield self.hs.get_event_sources().get_current_token_for_room( room_id=room_id ) ) room_token = pagin_config.from_token.room_key room_token = RoomStreamToken.parse(room_token) pagin_config.from_token = pagin_config.from_token.copy_and_replace( "room_key", str(room_token) ) source_config = pagin_config.get_source_config("room") with (yield self.pagination_lock.read(room_id)): membership, member_event_id = yield self.auth.check_in_room_or_world_readable( room_id, user_id ) if source_config.direction == 'b': # if we're going backwards, we might need to backfill. This # requires that we have a topo token. if room_token.topological: max_topo = room_token.topological else: max_topo = yield self.store.get_max_topological_token( room_id, room_token.stream ) if membership == Membership.LEAVE: # If they have left the room then clamp the token to be before # they left the room, to save the effort of loading from the # database. leave_token = yield self.store.get_topological_token_for_event( member_event_id ) leave_token = RoomStreamToken.parse(leave_token) if leave_token.topological < max_topo: source_config.from_key = str(leave_token) yield self.hs.get_handlers().federation_handler.maybe_backfill( room_id, max_topo ) events, next_key = yield self.store.paginate_room_events( room_id=room_id, from_key=source_config.from_key, to_key=source_config.to_key, direction=source_config.direction, limit=source_config.limit, event_filter=event_filter, ) next_token = pagin_config.from_token.copy_and_replace( "room_key", next_key ) if events: if event_filter: events = event_filter.filter(events) events = yield filter_events_for_client( self.store, user_id, events, is_peeking=(member_event_id is None), ) if not events: defer.returnValue({ "chunk": [], "start": pagin_config.from_token.to_string(), "end": next_token.to_string(), }) state = None if event_filter and event_filter.lazy_load_members() and len(events) > 0: # TODO: remove redundant members # FIXME: we also care about invite targets etc. state_filter = StateFilter.from_types( (EventTypes.Member, event.sender) for event in events ) state_ids = yield self.store.get_state_ids_for_event( events[0].event_id, state_filter=state_filter, ) if state_ids: state = yield self.store.get_events(list(state_ids.values())) state = state.values() time_now = self.clock.time_msec() chunk = { "chunk": ( yield self._event_serializer.serialize_events( events, time_now, as_client_event=as_client_event, ) ), "start": pagin_config.from_token.to_string(), "end": next_token.to_string(), } if state: chunk["state"] = ( yield self._event_serializer.serialize_events( state, time_now, as_client_event=as_client_event, ) ) defer.returnValue(chunk)