forked-synapse/synapse/handlers/presence.py
2016-02-19 11:50:48 +00:00

1048 lines
37 KiB
Python

# -*- 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
"""
from twisted.internet import defer, reactor
from contextlib import contextmanager
from synapse.api.errors import SynapseError
from synapse.api.constants import PresenceState
from synapse.storage.presence import UserPresenceState
from synapse.util.logcontext import preserve_fn
from synapse.util.logutils import log_function
from synapse.util.metrics import Measure
from synapse.util.wheel_timer import WheelTimer
from synapse.types import UserID
import synapse.metrics
from ._base import BaseHandler
import logging
logger = logging.getLogger(__name__)
metrics = synapse.metrics.get_metrics_for(__name__)
notified_presence_counter = metrics.register_counter("notified_presence")
presence_updates_counter = metrics.register_counter("presence_updates")
timers_fired_counter = metrics.register_counter("timers_fired")
federation_presence_counter = metrics.register_counter("federation_presence")
bump_active_time_counter = metrics.register_counter("bump_active_time")
# 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
assert LAST_ACTIVE_GRANULARITY < IDLE_TIMER
def user_presence_changed(distributor, user, statuscache):
return distributor.fire("user_presence_changed", user, statuscache)
def collect_presencelike_data(distributor, user, content):
return distributor.fire("collect_presencelike_data", user, content)
class PresenceHandler(BaseHandler):
def __init__(self, hs):
super(PresenceHandler, self).__init__(hs)
self.hs = hs
self.clock = hs.get_clock()
self.store = hs.get_datastore()
self.wheel_timer = WheelTimer()
self.notifier = hs.get_notifier()
self.federation = hs.get_replication_layer()
self.federation.register_edu_handler(
"m.presence", self.incoming_presence
)
self.federation.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"]),
)
)
self.federation.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"]),
)
)
self.federation.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
}
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.hs.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()
reactor.addSystemEventTrigger("before", "shutdown", self._on_shutdown)
self.serial_to_user = {}
self._next_serial = 1
# Keeps track of the number of *ongoing* syncs. While this is non zero
# a user will never go offline.
self.user_to_num_current_syncs = {}
# 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(
0 * 1000,
self.clock.looping_call,
self._handle_timeouts,
5000,
)
metrics.register_callback("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. Persiting %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 _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
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.hs.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_by(len(new_states))
if to_notify:
notified_presence_counter.inc_by(len(to_notify))
yield self._persist_and_notify(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:
_, _, hosts_to_states = yield self._get_interested_parties(
to_federation_ping.values()
)
self._push_to_remotes(hosts_to_states)
def _handle_timeouts(self):
"""Checks the presence of users that have timed out and updates as
appropriate.
"""
now = self.clock.time_msec()
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 = self.wheel_timer.fetch(now)
states = [
self.user_to_current_state.get(
user_id, UserPresenceState.default(user_id)
)
for user_id in set(users_to_check)
]
timers_fired_counter.inc_by(len(states))
changes = handle_timeouts(
states,
is_mine_fn=self.hs.is_mine_id,
user_to_num_current_syncs=self.user_to_num_current_syncs,
now=now,
)
preserve_fn(self._update_states)(changes)
@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():
if affect_presence:
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(),
)])
@contextmanager
def _user_syncing():
try:
yield
finally:
preserve_fn(_end)()
defer.returnValue(_user_syncing())
@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 states.items() 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({state.user_id: state for state in res})
missing = [user_id for user_id, state in states.items() 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 _get_interested_parties(self, states):
"""Given a list of states return which entities (rooms, users, servers)
are interested in the given states.
Returns:
3-tuple: `(room_ids_to_states, users_to_states, hosts_to_states)`,
with each item being a dict of `entity_name` -> `[UserPresenceState]`
"""
room_ids_to_states = {}
users_to_states = {}
for state in states:
events = yield self.store.get_rooms_for_user(state.user_id)
for e in events:
room_ids_to_states.setdefault(e.room_id, []).append(state)
plist = yield self.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)
hosts_to_states = {}
for room_id, states in room_ids_to_states.items():
hosts = yield self.store.get_joined_hosts_for_room(room_id)
for host in hosts:
hosts_to_states.setdefault(host, []).extend(states)
for user_id, states in users_to_states.items():
host = UserID.from_string(user_id).domain
hosts_to_states.setdefault(host, []).extend(states)
# TODO: de-dup hosts_to_states, as a single host might have multiple
# of same presence
defer.returnValue((room_ids_to_states, users_to_states, hosts_to_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 self._get_interested_parties(states)
room_ids_to_states, users_to_states, hosts_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.keys()]
)
self._push_to_remotes(hosts_to_states)
def _push_to_remotes(self, hosts_to_states):
"""Sends state updates to remote servers.
Args:
hosts_to_states (dict): Mapping `server_name` -> `[UserPresenceState]`
"""
now = self.clock.time_msec()
for host, states in hosts_to_states.items():
self.federation.send_edu(
destination=host,
edu_type="m.presence",
content={
"push": [
_format_user_presence_state(state, now)
for state in 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
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)
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_by(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 = 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([
_format_user_presence_state(state, now) for state in updates
])
@defer.inlineCallbacks
def set_state(self, target_user, state):
"""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,
"status_msg": status_msg if presence != PresenceState.OFFLINE else None
}
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.hs.is_mine(user):
state = yield self.current_state_for_user(user.to_string())
hosts = yield self.store.get_joined_hosts_for_room(room_id)
self._push_to_remotes({host: (state,) for host in hosts})
else:
user_ids = yield self.store.get_users_in_room(room_id)
user_ids = filter(self.hs.is_mine_id, user_ids)
states = yield self.current_state_for_users(user_ids)
self._push_to_remotes({user.domain: 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.hs.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,
)
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.hs.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.hs.is_mine(observed_user):
raise SynapseError(400, "User is not hosted on this Home Server")
# TODO: Don't auto accept
if self.hs.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)
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.hs.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_rooms = yield self.store.get_rooms_for_user(observer_user.to_string())
observed_rooms = yield self.store.get_rooms_for_user(observed_user.to_string())
observer_room_ids = set(r.room_id for r in observer_rooms)
observed_room_ids = set(r.room_id for r in observed_rooms)
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)
def should_notify(old_state, new_state):
"""Decides if a presence state change should be sent to interested parties.
"""
if old_state.status_msg != new_state.status_msg:
return True
if old_state.state == PresenceState.ONLINE:
if new_state.state != PresenceState.ONLINE:
# Always notify for online -> anything
return True
if new_state.currently_active != old_state.currently_active:
return True
if new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY:
# Always notify for a transition where last active gets bumped.
return True
if old_state.state != new_state.state:
return True
return False
def _format_user_presence_state(state, now):
"""Convert UserPresenceState to a format that can be sent down to clients
and to other servers.
"""
content = {
"presence": state.state,
"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):
self.hs = hs
self.clock = hs.get_clock()
self.store = hs.get_datastore()
@defer.inlineCallbacks
@log_function
def get_new_events(self, user, from_key, room_ids=None, include_offline=True,
**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.
user_id = user.to_string()
if from_key is not None:
from_key = int(from_key)
room_ids = room_ids or []
presence = self.hs.get_handlers().presence_handler
if not room_ids:
rooms = yield self.store.get_rooms_for_user(user_id)
room_ids = set(e.room_id for e in rooms)
user_ids_to_check = set()
for room_id in room_ids:
users = yield self.store.get_users_in_room(room_id)
user_ids_to_check.update(users)
plist = yield self.store.get_presence_list_accepted(user.localpart)
user_ids_to_check.update([row["observed_user_id"] for row in plist])
# Always include yourself. Only really matters for when the user is
# not in any rooms, but still.
user_ids_to_check.add(user_id)
max_token = self.store.get_current_presence_token()
if from_key:
user_ids_changed = self.store.presence_stream_cache.get_entities_changed(
user_ids_to_check, from_key,
)
else:
user_ids_changed = user_ids_to_check
updates = yield presence.current_state_for_users(user_ids_changed)
now = self.clock.time_msec()
defer.returnValue(([
{
"type": "m.presence",
"content": _format_user_presence_state(s, now),
}
for s in updates.values()
if include_offline or 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)
def handle_timeouts(user_states, is_mine_fn, user_to_num_current_syncs, 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
user_to_num_current_syncs (dict): Mapping of user_id to number of currently
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, user_to_num_current_syncs, now)
if new_state:
changes[state.user_id] = new_state
return changes.values()
def handle_timeout(state, is_mine, user_to_num_current_syncs, 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
user_to_num_current_syncs (dict): Mapping of user_id to number of currently
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 not user_to_num_current_syncs.get(user_id, 0):
if now - state.last_user_sync_ts > SYNC_ONLINE_TIMEOUT:
state = state.copy_and_replace(
state=PresenceState.OFFLINE,
status_msg=None,
)
changed = True
else:
# We expect to be poked occaisonally 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