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# -*- coding: utf-8 -*-
# Copyright 2015 OpenMarket Ltd
# Copyright 2017 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 twisted.internet import defer
from .push_rule_evaluator import PushRuleEvaluatorForEvent
from synapse.event_auth import get_user_power_level
from synapse.api.constants import EventTypes, Membership
from synapse.metrics import get_metrics_for
from synapse.util.caches import metrics as cache_metrics
from synapse.util.caches.descriptors import cached
from synapse.util.async import Linearizer
from synapse.state import POWER_KEY
from collections import namedtuple
logger = logging.getLogger(__name__)
rules_by_room = {}
push_metrics = get_metrics_for(__name__)
push_rules_invalidation_counter = push_metrics.register_counter(
"push_rules_invalidation_counter"
)
push_rules_state_size_counter = push_metrics.register_counter(
"push_rules_state_size_counter"
)
# Measures whether we use the fast path of using state deltas, or if we have to
# recalculate from scratch
push_rules_delta_state_cache_metric = cache_metrics.register_cache(
"cache",
size_callback=lambda: 0, # Meaningless size, as this isn't a cache that stores values
cache_name="push_rules_delta_state_cache_metric",
)
class BulkPushRuleEvaluator(object):
"""Calculates the outcome of push rules for an event for all users in the
room at once.
"""
def __init__(self, hs):
self.hs = hs
self.store = hs.get_datastore()
self.auth = hs.get_auth()
self.room_push_rule_cache_metrics = cache_metrics.register_cache(
"cache",
size_callback=lambda: 0, # There's not good value for this
cache_name="room_push_rule_cache",
)
@defer.inlineCallbacks
def _get_rules_for_event(self, event, context):
"""This gets the rules for all users in the room at the time of the event,
as well as the push rules for the invitee if the event is an invite.
Returns:
dict of user_id -> push_rules
"""
room_id = event.room_id
rules_for_room = self._get_rules_for_room(room_id)
rules_by_user = yield rules_for_room.get_rules(event, context)
# if this event is an invite event, we may need to run rules for the user
# who's been invited, otherwise they won't get told they've been invited
if event.type == 'm.room.member' and event.content['membership'] == 'invite':
invited = event.state_key
if invited and self.hs.is_mine_id(invited):
has_pusher = yield self.store.user_has_pusher(invited)
if has_pusher:
rules_by_user = dict(rules_by_user)
rules_by_user[invited] = yield self.store.get_push_rules_for_user(
invited
)
defer.returnValue(rules_by_user)
@cached()
def _get_rules_for_room(self, room_id):
"""Get the current RulesForRoom object for the given room id
Returns:
RulesForRoom
"""
# It's important that RulesForRoom gets added to self._get_rules_for_room.cache
# before any lookup methods get called on it as otherwise there may be
# a race if invalidate_all gets called (which assumes its in the cache)
return RulesForRoom(
self.hs, room_id, self._get_rules_for_room.cache,
self.room_push_rule_cache_metrics,
)
@defer.inlineCallbacks
def _get_power_levels_and_sender_level(self, event, context):
pl_event_id = context.prev_state_ids.get(POWER_KEY)
if pl_event_id:
# fastpath: if there's a power level event, that's all we need, and
# not having a power level event is an extreme edge case
pl_event = yield self.store.get_event(pl_event_id)
auth_events = {POWER_KEY: pl_event}
else:
auth_events_ids = yield self.auth.compute_auth_events(
event, context.prev_state_ids, for_verification=False,
)
auth_events = yield self.store.get_events(auth_events_ids)
auth_events = {
(e.type, e.state_key): e for e in auth_events.itervalues()
}
sender_level = get_user_power_level(event.sender, auth_events)
pl_event = auth_events.get(POWER_KEY)
defer.returnValue((pl_event.content if pl_event else {}, sender_level))
@defer.inlineCallbacks
def action_for_event_by_user(self, event, context):
"""Given an event and context, evaluate the push rules and insert the
results into the event_push_actions_staging table.
Returns:
Deferred
"""
rules_by_user = yield self._get_rules_for_event(event, context)
room_members = yield self.store.get_joined_users_from_context(
event, context
)
(power_levels, sender_power_level) = (
yield self._get_power_levels_and_sender_level(event, context)
)
evaluator = PushRuleEvaluatorForEvent(
event, len(room_members), sender_power_level, power_levels,
)
condition_cache = {}
for uid, rules in rules_by_user.iteritems():
if event.sender == uid:
continue
if not event.is_state():
is_ignored = yield self.store.is_ignored_by(event.sender, uid)
if is_ignored:
continue
display_name = None
profile_info = room_members.get(uid)
if profile_info:
display_name = profile_info.display_name
if not display_name:
# Handle the case where we are pushing a membership event to
# that user, as they might not be already joined.
if event.type == EventTypes.Member and event.state_key == uid:
display_name = event.content.get("displayname", None)
for rule in rules:
if 'enabled' in rule and not rule['enabled']:
continue
matches = _condition_checker(
evaluator, rule['conditions'], uid, display_name, condition_cache
)
if matches:
actions = [x for x in rule['actions'] if x != 'dont_notify']
if actions and 'notify' in actions:
yield self.store.add_push_actions_to_staging(
event.event_id, uid, actions,
)
break
def _condition_checker(evaluator, conditions, uid, display_name, cache):
for cond in conditions:
_id = cond.get("_id", None)
if _id:
res = cache.get(_id, None)
if res is False:
return False
elif res is True:
continue
res = evaluator.matches(cond, uid, display_name)
if _id:
cache[_id] = bool(res)
if not res:
return False
return True
class RulesForRoom(object):
"""Caches push rules for users in a room.
This efficiently handles users joining/leaving the room by not invalidating
the entire cache for the room.
"""
def __init__(self, hs, room_id, rules_for_room_cache, room_push_rule_cache_metrics):
"""
Args:
hs (HomeServer)
room_id (str)
rules_for_room_cache(Cache): The cache object that caches these
RoomsForUser objects.
room_push_rule_cache_metrics (CacheMetric)
"""
self.room_id = room_id
self.is_mine_id = hs.is_mine_id
self.store = hs.get_datastore()
self.room_push_rule_cache_metrics = room_push_rule_cache_metrics
self.linearizer = Linearizer(name="rules_for_room")
self.member_map = {} # event_id -> (user_id, state)
self.rules_by_user = {} # user_id -> rules
# The last state group we updated the caches for. If the state_group of
# a new event comes along, we know that we can just return the cached
# result.
# On invalidation of the rules themselves (if the user changes them),
# we invalidate everything and set state_group to `object()`
self.state_group = object()
# A sequence number to keep track of when we're allowed to update the
# cache. We bump the sequence number when we invalidate the cache. If
# the sequence number changes while we're calculating stuff we should
# not update the cache with it.
self.sequence = 0
# A cache of user_ids that we *know* aren't interesting, e.g. user_ids
# owned by AS's, or remote users, etc. (I.e. users we will never need to
# calculate push for)
# These never need to be invalidated as we will never set up push for
# them.
self.uninteresting_user_set = set()
# We need to be clever on the invalidating caches callbacks, as
# otherwise the invalidation callback holds a reference to the object,
# potentially causing it to leak.
# To get around this we pass a function that on invalidations looks ups
# the RoomsForUser entry in the cache, rather than keeping a reference
# to self around in the callback.
self.invalidate_all_cb = _Invalidation(rules_for_room_cache, room_id)
@defer.inlineCallbacks
def get_rules(self, event, context):
"""Given an event context return the rules for all users who are
currently in the room.
"""
state_group = context.state_group
if state_group and self.state_group == state_group:
logger.debug("Using cached rules for %r", self.room_id)
self.room_push_rule_cache_metrics.inc_hits()
defer.returnValue(self.rules_by_user)
with (yield self.linearizer.queue(())):
if state_group and self.state_group == state_group:
logger.debug("Using cached rules for %r", self.room_id)
self.room_push_rule_cache_metrics.inc_hits()
defer.returnValue(self.rules_by_user)
self.room_push_rule_cache_metrics.inc_misses()
ret_rules_by_user = {}
missing_member_event_ids = {}
if state_group and self.state_group == context.prev_group:
# If we have a simple delta then we can reuse most of the previous
# results.
ret_rules_by_user = self.rules_by_user
current_state_ids = context.delta_ids
push_rules_delta_state_cache_metric.inc_hits()
else:
current_state_ids = context.current_state_ids
push_rules_delta_state_cache_metric.inc_misses()
push_rules_state_size_counter.inc_by(len(current_state_ids))
logger.debug(
"Looking for member changes in %r %r", state_group, current_state_ids
)
# Loop through to see which member events we've seen and have rules
# for and which we need to fetch
for key in current_state_ids:
typ, user_id = key
if typ != EventTypes.Member:
continue
if user_id in self.uninteresting_user_set:
continue
if not self.is_mine_id(user_id):
self.uninteresting_user_set.add(user_id)
continue
if self.store.get_if_app_services_interested_in_user(user_id):
self.uninteresting_user_set.add(user_id)
continue
event_id = current_state_ids[key]
res = self.member_map.get(event_id, None)
if res:
user_id, state = res
if state == Membership.JOIN:
rules = self.rules_by_user.get(user_id, None)
if rules:
ret_rules_by_user[user_id] = rules
continue
# If a user has left a room we remove their push rule. If they
# joined then we readd it later in _update_rules_with_member_event_ids
ret_rules_by_user.pop(user_id, None)
missing_member_event_ids[user_id] = event_id
if missing_member_event_ids:
# If we have some memebr events we haven't seen, look them up
# and fetch push rules for them if appropriate.
logger.debug("Found new member events %r", missing_member_event_ids)
yield self._update_rules_with_member_event_ids(
ret_rules_by_user, missing_member_event_ids, state_group, event
)
else:
# The push rules didn't change but lets update the cache anyway
self.update_cache(
self.sequence,
members={}, # There were no membership changes
rules_by_user=ret_rules_by_user,
state_group=state_group
)
if logger.isEnabledFor(logging.DEBUG):
logger.debug(
"Returning push rules for %r %r",
self.room_id, ret_rules_by_user.keys(),
)
defer.returnValue(ret_rules_by_user)
@defer.inlineCallbacks
def _update_rules_with_member_event_ids(self, ret_rules_by_user, member_event_ids,
state_group, event):
"""Update the partially filled rules_by_user dict by fetching rules for
any newly joined users in the `member_event_ids` list.
Args:
ret_rules_by_user (dict): Partiallly filled dict of push rules. Gets
updated with any new rules.
member_event_ids (list): List of event ids for membership events that
have happened since the last time we filled rules_by_user
state_group: The state group we are currently computing push rules
for. Used when updating the cache.
"""
sequence = self.sequence
rows = yield self.store._simple_select_many_batch(
table="room_memberships",
column="event_id",
iterable=member_event_ids.values(),
retcols=('user_id', 'membership', 'event_id'),
keyvalues={},
batch_size=500,
desc="_get_rules_for_member_event_ids",
)
members = {
row["event_id"]: (row["user_id"], row["membership"])
for row in rows
}
# If the event is a join event then it will be in current state evnts
# map but not in the DB, so we have to explicitly insert it.
if event.type == EventTypes.Member:
for event_id in member_event_ids.itervalues():
if event_id == event.event_id:
members[event_id] = (event.state_key, event.membership)
if logger.isEnabledFor(logging.DEBUG):
logger.debug("Found members %r: %r", self.room_id, members.values())
interested_in_user_ids = set(
user_id for user_id, membership in members.itervalues()
if membership == Membership.JOIN
)
logger.debug("Joined: %r", interested_in_user_ids)
if_users_with_pushers = yield self.store.get_if_users_have_pushers(
interested_in_user_ids,
on_invalidate=self.invalidate_all_cb,
)
user_ids = set(
uid for uid, have_pusher in if_users_with_pushers.iteritems() if have_pusher
)
logger.debug("With pushers: %r", user_ids)
users_with_receipts = yield self.store.get_users_with_read_receipts_in_room(
self.room_id, on_invalidate=self.invalidate_all_cb,
)
logger.debug("With receipts: %r", users_with_receipts)
# any users with pushers must be ours: they have pushers
for uid in users_with_receipts:
if uid in interested_in_user_ids:
user_ids.add(uid)
rules_by_user = yield self.store.bulk_get_push_rules(
user_ids, on_invalidate=self.invalidate_all_cb,
)
ret_rules_by_user.update(
item for item in rules_by_user.iteritems() if item[0] is not None
)
self.update_cache(sequence, members, ret_rules_by_user, state_group)
def invalidate_all(self):
# Note: Don't hand this function directly to an invalidation callback
# as it keeps a reference to self and will stop this instance from being
# GC'd if it gets dropped from the rules_to_user cache. Instead use
# `self.invalidate_all_cb`
logger.debug("Invalidating RulesForRoom for %r", self.room_id)
self.sequence += 1
self.state_group = object()
self.member_map = {}
self.rules_by_user = {}
push_rules_invalidation_counter.inc()
def update_cache(self, sequence, members, rules_by_user, state_group):
if sequence == self.sequence:
self.member_map.update(members)
self.rules_by_user = rules_by_user
self.state_group = state_group
class _Invalidation(namedtuple("_Invalidation", ("cache", "room_id"))):
# We rely on _CacheContext implementing __eq__ and __hash__ sensibly,
# which namedtuple does for us (i.e. two _CacheContext are the same if
# their caches and keys match). This is important in particular to
# dedupe when we add callbacks to lru cache nodes, otherwise the number
# of callbacks would grow.
def __call__(self):
rules = self.cache.get(self.room_id, None, update_metrics=False)
if rules:
rules.invalidate_all()
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