# -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket 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. """This module is responsible for keeping track of presence status of local and remote users. The methods that define policy are: - PresenceHandler._update_states - PresenceHandler._handle_timeouts - should_notify """ import logging from contextlib import contextmanager from six import iteritems, itervalues from prometheus_client import Counter from twisted.internet import defer from synapse.api.constants import PresenceState from synapse.api.errors import SynapseError from synapse.metrics import LaterGauge from synapse.storage.presence import UserPresenceState from synapse.types import UserID, get_domain_from_id from synapse.util.async_helpers import Linearizer from synapse.util.caches.descriptors import cachedInlineCallbacks from synapse.util.logcontext import run_in_background from synapse.util.logutils import log_function from synapse.util.metrics import Measure from synapse.util.wheel_timer import WheelTimer logger = logging.getLogger(__name__) notified_presence_counter = Counter("synapse_handler_presence_notified_presence", "") federation_presence_out_counter = Counter( "synapse_handler_presence_federation_presence_out", "") presence_updates_counter = Counter("synapse_handler_presence_presence_updates", "") timers_fired_counter = Counter("synapse_handler_presence_timers_fired", "") federation_presence_counter = Counter("synapse_handler_presence_federation_presence", "") bump_active_time_counter = Counter("synapse_handler_presence_bump_active_time", "") get_updates_counter = Counter("synapse_handler_presence_get_updates", "", ["type"]) notify_reason_counter = Counter( "synapse_handler_presence_notify_reason", "", ["reason"]) state_transition_counter = Counter( "synapse_handler_presence_state_transition", "", ["from", "to"] ) # If a user was last active in the last LAST_ACTIVE_GRANULARITY, consider them # "currently_active" LAST_ACTIVE_GRANULARITY = 60 * 1000 # How long to wait until a new /events or /sync request before assuming # the client has gone. SYNC_ONLINE_TIMEOUT = 30 * 1000 # How long to wait before marking the user as idle. Compared against last active IDLE_TIMER = 5 * 60 * 1000 # How often we expect remote servers to resend us presence. FEDERATION_TIMEOUT = 30 * 60 * 1000 # How often to resend presence to remote servers FEDERATION_PING_INTERVAL = 25 * 60 * 1000 # How long we will wait before assuming that the syncs from an external process # are dead. EXTERNAL_PROCESS_EXPIRY = 5 * 60 * 1000 assert LAST_ACTIVE_GRANULARITY < IDLE_TIMER class PresenceHandler(object): def __init__(self, hs): """ Args: hs (synapse.server.HomeServer): """ self.is_mine = hs.is_mine self.is_mine_id = hs.is_mine_id self.clock = hs.get_clock() self.store = hs.get_datastore() self.wheel_timer = WheelTimer() self.notifier = hs.get_notifier() self.federation = hs.get_federation_sender() self.state = hs.get_state_handler() federation_registry = hs.get_federation_registry() federation_registry.register_edu_handler( "m.presence", self.incoming_presence ) federation_registry.register_edu_handler( "m.presence_invite", lambda origin, content: self.invite_presence( observed_user=UserID.from_string(content["observed_user"]), observer_user=UserID.from_string(content["observer_user"]), ) ) federation_registry.register_edu_handler( "m.presence_accept", lambda origin, content: self.accept_presence( observed_user=UserID.from_string(content["observed_user"]), observer_user=UserID.from_string(content["observer_user"]), ) ) federation_registry.register_edu_handler( "m.presence_deny", lambda origin, content: self.deny_presence( observed_user=UserID.from_string(content["observed_user"]), observer_user=UserID.from_string(content["observer_user"]), ) ) distributor = hs.get_distributor() distributor.observe("user_joined_room", self.user_joined_room) active_presence = self.store.take_presence_startup_info() # A dictionary of the current state of users. This is prefilled with # non-offline presence from the DB. We should fetch from the DB if # we can't find a users presence in here. self.user_to_current_state = { state.user_id: state for state in active_presence } LaterGauge( "synapse_handlers_presence_user_to_current_state_size", "", [], lambda: len(self.user_to_current_state) ) now = self.clock.time_msec() for state in active_presence: self.wheel_timer.insert( now=now, obj=state.user_id, then=state.last_active_ts + IDLE_TIMER, ) self.wheel_timer.insert( now=now, obj=state.user_id, then=state.last_user_sync_ts + SYNC_ONLINE_TIMEOUT, ) if self.is_mine_id(state.user_id): self.wheel_timer.insert( now=now, obj=state.user_id, then=state.last_federation_update_ts + FEDERATION_PING_INTERVAL, ) else: self.wheel_timer.insert( now=now, obj=state.user_id, then=state.last_federation_update_ts + FEDERATION_TIMEOUT, ) # Set of users who have presence in the `user_to_current_state` that # have not yet been persisted self.unpersisted_users_changes = set() hs.get_reactor().addSystemEventTrigger("before", "shutdown", self._on_shutdown) self.serial_to_user = {} self._next_serial = 1 # Keeps track of the number of *ongoing* syncs on this process. While # this is non zero a user will never go offline. self.user_to_num_current_syncs = {} # Keeps track of the number of *ongoing* syncs on other processes. # While any sync is ongoing on another process the user will never # go offline. # Each process has a unique identifier and an update frequency. If # no update is received from that process within the update period then # we assume that all the sync requests on that process have stopped. # Stored as a dict from process_id to set of user_id, and a dict of # process_id to millisecond timestamp last updated. self.external_process_to_current_syncs = {} self.external_process_last_updated_ms = {} self.external_sync_linearizer = Linearizer(name="external_sync_linearizer") # Start a LoopingCall in 30s that fires every 5s. # The initial delay is to allow disconnected clients a chance to # reconnect before we treat them as offline. self.clock.call_later( 30, self.clock.looping_call, self._handle_timeouts, 5000, ) self.clock.call_later( 60, self.clock.looping_call, self._persist_unpersisted_changes, 60 * 1000, ) LaterGauge("synapse_handlers_presence_wheel_timer_size", "", [], lambda: len(self.wheel_timer)) @defer.inlineCallbacks def _on_shutdown(self): """Gets called when shutting down. This lets us persist any updates that we haven't yet persisted, e.g. updates that only changes some internal timers. This allows changes to persist across startup without having to persist every single change. If this does not run it simply means that some of the timers will fire earlier than they should when synapse is restarted. This affect of this is some spurious presence changes that will self-correct. """ logger.info( "Performing _on_shutdown. Persisting %d unpersisted changes", len(self.user_to_current_state) ) if self.unpersisted_users_changes: yield self.store.update_presence([ self.user_to_current_state[user_id] for user_id in self.unpersisted_users_changes ]) logger.info("Finished _on_shutdown") @defer.inlineCallbacks def _persist_unpersisted_changes(self): """We periodically persist the unpersisted changes, as otherwise they may stack up and slow down shutdown times. """ logger.info( "Performing _persist_unpersisted_changes. Persisting %d unpersisted changes", len(self.unpersisted_users_changes) ) unpersisted = self.unpersisted_users_changes self.unpersisted_users_changes = set() if unpersisted: yield self.store.update_presence([ self.user_to_current_state[user_id] for user_id in unpersisted ]) logger.info("Finished _persist_unpersisted_changes") @defer.inlineCallbacks def _update_states_and_catch_exception(self, new_states): try: res = yield self._update_states(new_states) defer.returnValue(res) except Exception: logger.exception("Error updating presence") @defer.inlineCallbacks def _update_states(self, new_states): """Updates presence of users. Sets the appropriate timeouts. Pokes the notifier and federation if and only if the changed presence state should be sent to clients/servers. """ now = self.clock.time_msec() with Measure(self.clock, "presence_update_states"): # NOTE: We purposefully don't yield between now and when we've # calculated what we want to do with the new states, to avoid races. to_notify = {} # Changes we want to notify everyone about to_federation_ping = {} # These need sending keep-alives # Only bother handling the last presence change for each user new_states_dict = {} for new_state in new_states: new_states_dict[new_state.user_id] = new_state new_state = new_states_dict.values() for new_state in new_states: user_id = new_state.user_id # Its fine to not hit the database here, as the only thing not in # the current state cache are OFFLINE states, where the only field # of interest is last_active which is safe enough to assume is 0 # here. prev_state = self.user_to_current_state.get( user_id, UserPresenceState.default(user_id) ) new_state, should_notify, should_ping = handle_update( prev_state, new_state, is_mine=self.is_mine_id(user_id), wheel_timer=self.wheel_timer, now=now ) self.user_to_current_state[user_id] = new_state if should_notify: to_notify[user_id] = new_state elif should_ping: to_federation_ping[user_id] = new_state # TODO: We should probably ensure there are no races hereafter presence_updates_counter.inc(len(new_states)) if to_notify: notified_presence_counter.inc(len(to_notify)) yield self._persist_and_notify(list(to_notify.values())) self.unpersisted_users_changes |= set(s.user_id for s in new_states) self.unpersisted_users_changes -= set(to_notify.keys()) to_federation_ping = { user_id: state for user_id, state in to_federation_ping.items() if user_id not in to_notify } if to_federation_ping: federation_presence_out_counter.inc(len(to_federation_ping)) self._push_to_remotes(to_federation_ping.values()) def _handle_timeouts(self): """Checks the presence of users that have timed out and updates as appropriate. """ logger.info("Handling presence timeouts") now = self.clock.time_msec() try: with Measure(self.clock, "presence_handle_timeouts"): # Fetch the list of users that *may* have timed out. Things may have # changed since the timeout was set, so we won't necessarily have to # take any action. users_to_check = set(self.wheel_timer.fetch(now)) # Check whether the lists of syncing processes from an external # process have expired. expired_process_ids = [ process_id for process_id, last_update in self.external_process_last_updated_ms.items() if now - last_update > EXTERNAL_PROCESS_EXPIRY ] for process_id in expired_process_ids: users_to_check.update( self.external_process_last_updated_ms.pop(process_id, ()) ) self.external_process_last_update.pop(process_id) states = [ self.user_to_current_state.get( user_id, UserPresenceState.default(user_id) ) for user_id in users_to_check ] timers_fired_counter.inc(len(states)) changes = handle_timeouts( states, is_mine_fn=self.is_mine_id, syncing_user_ids=self.get_currently_syncing_users(), now=now, ) run_in_background(self._update_states_and_catch_exception, changes) except Exception: logger.exception("Exception in _handle_timeouts loop") @defer.inlineCallbacks def bump_presence_active_time(self, user): """We've seen the user do something that indicates they're interacting with the app. """ user_id = user.to_string() bump_active_time_counter.inc() prev_state = yield self.current_state_for_user(user_id) new_fields = { "last_active_ts": self.clock.time_msec(), } if prev_state.state == PresenceState.UNAVAILABLE: new_fields["state"] = PresenceState.ONLINE yield self._update_states([prev_state.copy_and_replace(**new_fields)]) @defer.inlineCallbacks def user_syncing(self, user_id, affect_presence=True): """Returns a context manager that should surround any stream requests from the user. This allows us to keep track of who is currently streaming and who isn't without having to have timers outside of this module to avoid flickering when users disconnect/reconnect. Args: user_id (str) affect_presence (bool): If false this function will be a no-op. Useful for streams that are not associated with an actual client that is being used by a user. """ if affect_presence: curr_sync = self.user_to_num_current_syncs.get(user_id, 0) self.user_to_num_current_syncs[user_id] = curr_sync + 1 prev_state = yield self.current_state_for_user(user_id) if prev_state.state == PresenceState.OFFLINE: # If they're currently offline then bring them online, otherwise # just update the last sync times. yield self._update_states([prev_state.copy_and_replace( state=PresenceState.ONLINE, last_active_ts=self.clock.time_msec(), last_user_sync_ts=self.clock.time_msec(), )]) else: yield self._update_states([prev_state.copy_and_replace( last_user_sync_ts=self.clock.time_msec(), )]) @defer.inlineCallbacks def _end(): try: self.user_to_num_current_syncs[user_id] -= 1 prev_state = yield self.current_state_for_user(user_id) yield self._update_states([prev_state.copy_and_replace( last_user_sync_ts=self.clock.time_msec(), )]) except Exception: logger.exception("Error updating presence after sync") @contextmanager def _user_syncing(): try: yield finally: if affect_presence: run_in_background(_end) defer.returnValue(_user_syncing()) def get_currently_syncing_users(self): """Get the set of user ids that are currently syncing on this HS. Returns: set(str): A set of user_id strings. """ syncing_user_ids = { user_id for user_id, count in self.user_to_num_current_syncs.items() if count } for user_ids in self.external_process_to_current_syncs.values(): syncing_user_ids.update(user_ids) return syncing_user_ids @defer.inlineCallbacks def update_external_syncs_row(self, process_id, user_id, is_syncing, sync_time_msec): """Update the syncing users for an external process as a delta. Args: process_id (str): An identifier for the process the users are syncing against. This allows synapse to process updates as user start and stop syncing against a given process. user_id (str): The user who has started or stopped syncing is_syncing (bool): Whether or not the user is now syncing sync_time_msec(int): Time in ms when the user was last syncing """ with (yield self.external_sync_linearizer.queue(process_id)): prev_state = yield self.current_state_for_user(user_id) process_presence = self.external_process_to_current_syncs.setdefault( process_id, set() ) updates = [] if is_syncing and user_id not in process_presence: if prev_state.state == PresenceState.OFFLINE: updates.append(prev_state.copy_and_replace( state=PresenceState.ONLINE, last_active_ts=sync_time_msec, last_user_sync_ts=sync_time_msec, )) else: updates.append(prev_state.copy_and_replace( last_user_sync_ts=sync_time_msec, )) process_presence.add(user_id) elif user_id in process_presence: updates.append(prev_state.copy_and_replace( last_user_sync_ts=sync_time_msec, )) if not is_syncing: process_presence.discard(user_id) if updates: yield self._update_states(updates) self.external_process_last_updated_ms[process_id] = self.clock.time_msec() @defer.inlineCallbacks def update_external_syncs_clear(self, process_id): """Marks all users that had been marked as syncing by a given process as offline. Used when the process has stopped/disappeared. """ with (yield self.external_sync_linearizer.queue(process_id)): process_presence = self.external_process_to_current_syncs.pop( process_id, set() ) prev_states = yield self.current_state_for_users(process_presence) time_now_ms = self.clock.time_msec() yield self._update_states([ prev_state.copy_and_replace( last_user_sync_ts=time_now_ms, ) for prev_state in itervalues(prev_states) ]) self.external_process_last_updated_ms.pop(process_id, None) @defer.inlineCallbacks def current_state_for_user(self, user_id): """Get the current presence state for a user. """ res = yield self.current_state_for_users([user_id]) defer.returnValue(res[user_id]) @defer.inlineCallbacks def current_state_for_users(self, user_ids): """Get the current presence state for multiple users. Returns: dict: `user_id` -> `UserPresenceState` """ states = { user_id: self.user_to_current_state.get(user_id, None) for user_id in user_ids } missing = [user_id for user_id, state in iteritems(states) if not state] if missing: # There are things not in our in memory cache. Lets pull them out of # the database. res = yield self.store.get_presence_for_users(missing) states.update(res) missing = [user_id for user_id, state in iteritems(states) if not state] if missing: new = { user_id: UserPresenceState.default(user_id) for user_id in missing } states.update(new) self.user_to_current_state.update(new) defer.returnValue(states) @defer.inlineCallbacks def _persist_and_notify(self, states): """Persist states in the database, poke the notifier and send to interested remote servers """ stream_id, max_token = yield self.store.update_presence(states) parties = yield get_interested_parties(self.store, states) room_ids_to_states, users_to_states = parties self.notifier.on_new_event( "presence_key", stream_id, rooms=room_ids_to_states.keys(), users=[UserID.from_string(u) for u in users_to_states] ) self._push_to_remotes(states) @defer.inlineCallbacks def notify_for_states(self, state, stream_id): parties = yield get_interested_parties(self.store, [state]) room_ids_to_states, users_to_states = parties self.notifier.on_new_event( "presence_key", stream_id, rooms=room_ids_to_states.keys(), users=[UserID.from_string(u) for u in users_to_states] ) def _push_to_remotes(self, states): """Sends state updates to remote servers. Args: states (list(UserPresenceState)) """ self.federation.send_presence(states) @defer.inlineCallbacks def incoming_presence(self, origin, content): """Called when we receive a `m.presence` EDU from a remote server. """ now = self.clock.time_msec() updates = [] for push in content.get("push", []): # A "push" contains a list of presence that we are probably interested # in. # TODO: Actually check if we're interested, rather than blindly # accepting presence updates. user_id = push.get("user_id", None) if not user_id: logger.info( "Got presence update from %r with no 'user_id': %r", origin, push, ) continue if get_domain_from_id(user_id) != origin: logger.info( "Got presence update from %r with bad 'user_id': %r", origin, user_id, ) continue presence_state = push.get("presence", None) if not presence_state: logger.info( "Got presence update from %r with no 'presence_state': %r", origin, push, ) continue new_fields = { "state": presence_state, "last_federation_update_ts": now, } last_active_ago = push.get("last_active_ago", None) if last_active_ago is not None: new_fields["last_active_ts"] = now - last_active_ago new_fields["status_msg"] = push.get("status_msg", None) new_fields["currently_active"] = push.get("currently_active", False) prev_state = yield self.current_state_for_user(user_id) updates.append(prev_state.copy_and_replace(**new_fields)) if updates: federation_presence_counter.inc(len(updates)) yield self._update_states(updates) @defer.inlineCallbacks def get_state(self, target_user, as_event=False): results = yield self.get_states( [target_user.to_string()], as_event=as_event, ) defer.returnValue(results[0]) @defer.inlineCallbacks def get_states(self, target_user_ids, as_event=False): """Get the presence state for users. Args: target_user_ids (list) as_event (bool): Whether to format it as a client event or not. Returns: list """ updates = yield self.current_state_for_users(target_user_ids) updates = list(updates.values()) for user_id in set(target_user_ids) - set(u.user_id for u in updates): updates.append(UserPresenceState.default(user_id)) now = self.clock.time_msec() if as_event: defer.returnValue([ { "type": "m.presence", "content": format_user_presence_state(state, now), } for state in updates ]) else: defer.returnValue(updates) @defer.inlineCallbacks def set_state(self, target_user, state, ignore_status_msg=False): """Set the presence state of the user. """ status_msg = state.get("status_msg", None) presence = state["presence"] valid_presence = ( PresenceState.ONLINE, PresenceState.UNAVAILABLE, PresenceState.OFFLINE ) if presence not in valid_presence: raise SynapseError(400, "Invalid presence state") user_id = target_user.to_string() prev_state = yield self.current_state_for_user(user_id) new_fields = { "state": presence } if not ignore_status_msg: msg = status_msg if presence != PresenceState.OFFLINE else None new_fields["status_msg"] = msg if presence == PresenceState.ONLINE: new_fields["last_active_ts"] = self.clock.time_msec() yield self._update_states([prev_state.copy_and_replace(**new_fields)]) @defer.inlineCallbacks def user_joined_room(self, user, room_id): """Called (via the distributor) when a user joins a room. This funciton sends presence updates to servers, either: 1. the joining user is a local user and we send their presence to all servers in the room. 2. the joining user is a remote user and so we send presence for all local users in the room. """ # We only need to send presence to servers that don't have it yet. We # don't need to send to local clients here, as that is done as part # of the event stream/sync. # TODO: Only send to servers not already in the room. if self.is_mine(user): state = yield self.current_state_for_user(user.to_string()) self._push_to_remotes([state]) else: user_ids = yield self.store.get_users_in_room(room_id) user_ids = list(filter(self.is_mine_id, user_ids)) states = yield self.current_state_for_users(user_ids) self._push_to_remotes(list(states.values())) @defer.inlineCallbacks def get_presence_list(self, observer_user, accepted=None): """Returns the presence for all users in their presence list. """ if not self.is_mine(observer_user): raise SynapseError(400, "User is not hosted on this Home Server") presence_list = yield self.store.get_presence_list( observer_user.localpart, accepted=accepted ) results = yield self.get_states( target_user_ids=[row["observed_user_id"] for row in presence_list], as_event=False, ) now = self.clock.time_msec() results[:] = [format_user_presence_state(r, now) for r in results] is_accepted = { row["observed_user_id"]: row["accepted"] for row in presence_list } for result in results: result.update({ "accepted": is_accepted, }) defer.returnValue(results) @defer.inlineCallbacks def send_presence_invite(self, observer_user, observed_user): """Sends a presence invite. """ yield self.store.add_presence_list_pending( observer_user.localpart, observed_user.to_string() ) if self.is_mine(observed_user): yield self.invite_presence(observed_user, observer_user) else: yield self.federation.send_edu( destination=observed_user.domain, edu_type="m.presence_invite", content={ "observed_user": observed_user.to_string(), "observer_user": observer_user.to_string(), } ) @defer.inlineCallbacks def invite_presence(self, observed_user, observer_user): """Handles new presence invites. """ if not self.is_mine(observed_user): raise SynapseError(400, "User is not hosted on this Home Server") # TODO: Don't auto accept if self.is_mine(observer_user): yield self.accept_presence(observed_user, observer_user) else: self.federation.send_edu( destination=observer_user.domain, edu_type="m.presence_accept", content={ "observed_user": observed_user.to_string(), "observer_user": observer_user.to_string(), } ) state_dict = yield self.get_state(observed_user, as_event=False) state_dict = format_user_presence_state(state_dict, self.clock.time_msec()) self.federation.send_edu( destination=observer_user.domain, edu_type="m.presence", content={ "push": [state_dict] } ) @defer.inlineCallbacks def accept_presence(self, observed_user, observer_user): """Handles a m.presence_accept EDU. Mark a presence invite from a local or remote user as accepted in a local user's presence list. Starts polling for presence updates from the local or remote user. Args: observed_user(UserID): The user to update in the presence list. observer_user(UserID): The owner of the presence list to update. """ yield self.store.set_presence_list_accepted( observer_user.localpart, observed_user.to_string() ) @defer.inlineCallbacks def deny_presence(self, observed_user, observer_user): """Handle a m.presence_deny EDU. Removes a local or remote user from a local user's presence list. Args: observed_user(UserID): The local or remote user to remove from the list. observer_user(UserID): The local owner of the presence list. Returns: A Deferred. """ yield self.store.del_presence_list( observer_user.localpart, observed_user.to_string() ) # TODO(paul): Inform the user somehow? @defer.inlineCallbacks def drop(self, observed_user, observer_user): """Remove a local or remote user from a local user's presence list and unsubscribe the local user from updates that user. Args: observed_user(UserId): The local or remote user to remove from the list. observer_user(UserId): The local owner of the presence list. Returns: A Deferred. """ if not self.is_mine(observer_user): raise SynapseError(400, "User is not hosted on this Home Server") yield self.store.del_presence_list( observer_user.localpart, observed_user.to_string() ) # TODO: Inform the remote that we've dropped the presence list. @defer.inlineCallbacks def is_visible(self, observed_user, observer_user): """Returns whether a user can see another user's presence. """ observer_room_ids = yield self.store.get_rooms_for_user( observer_user.to_string() ) observed_room_ids = yield self.store.get_rooms_for_user( observed_user.to_string() ) if observer_room_ids & observed_room_ids: defer.returnValue(True) accepted_observers = yield self.store.get_presence_list_observers_accepted( observed_user.to_string() ) defer.returnValue(observer_user.to_string() in accepted_observers) @defer.inlineCallbacks def get_all_presence_updates(self, last_id, current_id): """ Gets a list of presence update rows from between the given stream ids. Each row has: - stream_id(str) - user_id(str) - state(str) - last_active_ts(int) - last_federation_update_ts(int) - last_user_sync_ts(int) - status_msg(int) - currently_active(int) """ # TODO(markjh): replicate the unpersisted changes. # This could use the in-memory stores for recent changes. rows = yield self.store.get_all_presence_updates(last_id, current_id) defer.returnValue(rows) def should_notify(old_state, new_state): """Decides if a presence state change should be sent to interested parties. """ if old_state == new_state: return False if old_state.status_msg != new_state.status_msg: notify_reason_counter.labels("status_msg_change").inc() return True if old_state.state != new_state.state: notify_reason_counter.labels("state_change").inc() state_transition_counter.labels(old_state.state, new_state.state).inc() return True if old_state.state == PresenceState.ONLINE: if new_state.currently_active != old_state.currently_active: notify_reason_counter.labels("current_active_change").inc() return True if new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY: # Only notify about last active bumps if we're not currently acive if not new_state.currently_active: notify_reason_counter.labels("last_active_change_online").inc() return True elif new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY: # Always notify for a transition where last active gets bumped. notify_reason_counter.labels("last_active_change_not_online").inc() return True return False def format_user_presence_state(state, now, include_user_id=True): """Convert UserPresenceState to a format that can be sent down to clients and to other servers. The "user_id" is optional so that this function can be used to format presence updates for client /sync responses and for federation /send requests. """ content = { "presence": state.state, } if include_user_id: content["user_id"] = state.user_id if state.last_active_ts: content["last_active_ago"] = now - state.last_active_ts if state.status_msg and state.state != PresenceState.OFFLINE: content["status_msg"] = state.status_msg if state.state == PresenceState.ONLINE: content["currently_active"] = state.currently_active return content class PresenceEventSource(object): def __init__(self, hs): # We can't call get_presence_handler here because there's a cycle: # # Presence -> Notifier -> PresenceEventSource -> Presence # self.get_presence_handler = hs.get_presence_handler self.clock = hs.get_clock() self.store = hs.get_datastore() self.state = hs.get_state_handler() @defer.inlineCallbacks @log_function def get_new_events(self, user, from_key, room_ids=None, include_offline=True, explicit_room_id=None, **kwargs): # The process for getting presence events are: # 1. Get the rooms the user is in. # 2. Get the list of user in the rooms. # 3. Get the list of users that are in the user's presence list. # 4. If there is a from_key set, cross reference the list of users # with the `presence_stream_cache` to see which ones we actually # need to check. # 5. Load current state for the users. # # We don't try and limit the presence updates by the current token, as # sending down the rare duplicate is not a concern. with Measure(self.clock, "presence.get_new_events"): if from_key is not None: from_key = int(from_key) presence = self.get_presence_handler() stream_change_cache = self.store.presence_stream_cache max_token = self.store.get_current_presence_token() users_interested_in = yield self._get_interested_in(user, explicit_room_id) user_ids_changed = set() changed = None if from_key: changed = stream_change_cache.get_all_entities_changed(from_key) if changed is not None and len(changed) < 500: # For small deltas, its quicker to get all changes and then # work out if we share a room or they're in our presence list get_updates_counter.labels("stream").inc() for other_user_id in changed: if other_user_id in users_interested_in: user_ids_changed.add(other_user_id) else: # Too many possible updates. Find all users we can see and check # if any of them have changed. get_updates_counter.labels("full").inc() if from_key: user_ids_changed = stream_change_cache.get_entities_changed( users_interested_in, from_key, ) else: user_ids_changed = users_interested_in updates = yield presence.current_state_for_users(user_ids_changed) if include_offline: defer.returnValue((list(updates.values()), max_token)) else: defer.returnValue(([ s for s in itervalues(updates) if s.state != PresenceState.OFFLINE ], max_token)) def get_current_key(self): return self.store.get_current_presence_token() def get_pagination_rows(self, user, pagination_config, key): return self.get_new_events(user, from_key=None, include_offline=False) @cachedInlineCallbacks(num_args=2, cache_context=True) def _get_interested_in(self, user, explicit_room_id, cache_context): """Returns the set of users that the given user should see presence updates for """ user_id = user.to_string() plist = yield self.store.get_presence_list_accepted( user.localpart, on_invalidate=cache_context.invalidate, ) users_interested_in = set(row["observed_user_id"] for row in plist) users_interested_in.add(user_id) # So that we receive our own presence users_who_share_room = yield self.store.get_users_who_share_room_with_user( user_id, on_invalidate=cache_context.invalidate, ) users_interested_in.update(users_who_share_room) if explicit_room_id: user_ids = yield self.store.get_users_in_room( explicit_room_id, on_invalidate=cache_context.invalidate, ) users_interested_in.update(user_ids) defer.returnValue(users_interested_in) def handle_timeouts(user_states, is_mine_fn, syncing_user_ids, now): """Checks the presence of users that have timed out and updates as appropriate. Args: user_states(list): List of UserPresenceState's to check. is_mine_fn (fn): Function that returns if a user_id is ours syncing_user_ids (set): Set of user_ids with active syncs. now (int): Current time in ms. Returns: List of UserPresenceState updates """ changes = {} # Actual changes we need to notify people about for state in user_states: is_mine = is_mine_fn(state.user_id) new_state = handle_timeout(state, is_mine, syncing_user_ids, now) if new_state: changes[state.user_id] = new_state return list(changes.values()) def handle_timeout(state, is_mine, syncing_user_ids, now): """Checks the presence of the user to see if any of the timers have elapsed Args: state (UserPresenceState) is_mine (bool): Whether the user is ours syncing_user_ids (set): Set of user_ids with active syncs. now (int): Current time in ms. Returns: A UserPresenceState update or None if no update. """ if state.state == PresenceState.OFFLINE: # No timeouts are associated with offline states. return None changed = False user_id = state.user_id if is_mine: if state.state == PresenceState.ONLINE: if now - state.last_active_ts > IDLE_TIMER: # Currently online, but last activity ages ago so auto # idle state = state.copy_and_replace( state=PresenceState.UNAVAILABLE, ) changed = True elif now - state.last_active_ts > LAST_ACTIVE_GRANULARITY: # So that we send down a notification that we've # stopped updating. changed = True if now - state.last_federation_update_ts > FEDERATION_PING_INTERVAL: # Need to send ping to other servers to ensure they don't # timeout and set us to offline changed = True # If there are have been no sync for a while (and none ongoing), # set presence to offline if user_id not in syncing_user_ids: # If the user has done something recently but hasn't synced, # don't set them as offline. sync_or_active = max(state.last_user_sync_ts, state.last_active_ts) if now - sync_or_active > SYNC_ONLINE_TIMEOUT: state = state.copy_and_replace( state=PresenceState.OFFLINE, status_msg=None, ) changed = True else: # We expect to be poked occasionally by the other side. # This is to protect against forgetful/buggy servers, so that # no one gets stuck online forever. if now - state.last_federation_update_ts > FEDERATION_TIMEOUT: # The other side seems to have disappeared. state = state.copy_and_replace( state=PresenceState.OFFLINE, status_msg=None, ) changed = True return state if changed else None def handle_update(prev_state, new_state, is_mine, wheel_timer, now): """Given a presence update: 1. Add any appropriate timers. 2. Check if we should notify anyone. Args: prev_state (UserPresenceState) new_state (UserPresenceState) is_mine (bool): Whether the user is ours wheel_timer (WheelTimer) now (int): Time now in ms Returns: 3-tuple: `(new_state, persist_and_notify, federation_ping)` where: - new_state: is the state to actually persist - persist_and_notify (bool): whether to persist and notify people - federation_ping (bool): whether we should send a ping over federation """ user_id = new_state.user_id persist_and_notify = False federation_ping = False # If the users are ours then we want to set up a bunch of timers # to time things out. if is_mine: if new_state.state == PresenceState.ONLINE: # Idle timer wheel_timer.insert( now=now, obj=user_id, then=new_state.last_active_ts + IDLE_TIMER ) active = now - new_state.last_active_ts < LAST_ACTIVE_GRANULARITY new_state = new_state.copy_and_replace( currently_active=active, ) if active: wheel_timer.insert( now=now, obj=user_id, then=new_state.last_active_ts + LAST_ACTIVE_GRANULARITY ) if new_state.state != PresenceState.OFFLINE: # User has stopped syncing wheel_timer.insert( now=now, obj=user_id, then=new_state.last_user_sync_ts + SYNC_ONLINE_TIMEOUT ) last_federate = new_state.last_federation_update_ts if now - last_federate > FEDERATION_PING_INTERVAL: # Been a while since we've poked remote servers new_state = new_state.copy_and_replace( last_federation_update_ts=now, ) federation_ping = True else: wheel_timer.insert( now=now, obj=user_id, then=new_state.last_federation_update_ts + FEDERATION_TIMEOUT ) # Check whether the change was something worth notifying about if should_notify(prev_state, new_state): new_state = new_state.copy_and_replace( last_federation_update_ts=now, ) persist_and_notify = True return new_state, persist_and_notify, federation_ping @defer.inlineCallbacks def get_interested_parties(store, states): """Given a list of states return which entities (rooms, users) are interested in the given states. Args: states (list(UserPresenceState)) Returns: 2-tuple: `(room_ids_to_states, users_to_states)`, with each item being a dict of `entity_name` -> `[UserPresenceState]` """ room_ids_to_states = {} users_to_states = {} for state in states: room_ids = yield store.get_rooms_for_user(state.user_id) for room_id in room_ids: room_ids_to_states.setdefault(room_id, []).append(state) plist = yield store.get_presence_list_observers_accepted(state.user_id) for u in plist: users_to_states.setdefault(u, []).append(state) # Always notify self users_to_states.setdefault(state.user_id, []).append(state) defer.returnValue((room_ids_to_states, users_to_states)) @defer.inlineCallbacks def get_interested_remotes(store, states, state_handler): """Given a list of presence states figure out which remote servers should be sent which. All the presence states should be for local users only. Args: store (DataStore) states (list(UserPresenceState)) Returns: Deferred list of ([destinations], [UserPresenceState]), where for each row the list of UserPresenceState should be sent to each destination """ hosts_and_states = [] # First we look up the rooms each user is in (as well as any explicit # subscriptions), then for each distinct room we look up the remote # hosts in those rooms. room_ids_to_states, users_to_states = yield get_interested_parties(store, states) for room_id, states in iteritems(room_ids_to_states): hosts = yield state_handler.get_current_hosts_in_room(room_id) hosts_and_states.append((hosts, states)) for user_id, states in iteritems(users_to_states): host = get_domain_from_id(user_id) hosts_and_states.append(([host], states)) defer.returnValue(hosts_and_states)