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Refactor state module

Browse source 
We split out the actual state resolution algorithm to prepare for having
multiple versions.
This commit is contained in:
Erik Johnston 2018-08-07 15:22:40 +01:00
parent 0ad98e38d0
commit 119451dcd1
2 changed files with 325 additions and 296 deletions
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300
synapse/state.py → synapse/state/__init__.py
View file

@ -1,5 +1,6 @@
# -*- coding: utf-8 -*- # -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd # Copyright 2014-2016 OpenMarket Ltd
# Copyright 2018 New Vector Ltd
# #
# Licensed under the Apache License, Version 2.0 (the "License"); # Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License. # you may not use this file except in compliance with the License.
@ -13,20 +14,16 @@
# See the License for the specific language governing permissions and # See the License for the specific language governing permissions and
# limitations under the License. # limitations under the License.
import hashlib
import logging import logging
from collections import namedtuple from collections import namedtuple
from six import iteritems, iterkeys, itervalues from six import iteritems, itervalues
from frozendict import frozendict from frozendict import frozendict
from twisted.internet import defer from twisted.internet import defer
from synapse import event_auth
from synapse.api.constants import EventTypes from synapse.api.constants import EventTypes
from synapse.api.errors import AuthError
from synapse.events.snapshot import EventContext from synapse.events.snapshot import EventContext
from synapse.util.async import Linearizer from synapse.util.async import Linearizer
from synapse.util.caches import CACHE_SIZE_FACTOR from synapse.util.caches import CACHE_SIZE_FACTOR
@ -34,6 +31,8 @@ from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.logutils import log_function from synapse.util.logutils import log_function
from synapse.util.metrics import Measure from synapse.util.metrics import Measure
from .v1 import resolve_events_with_factory, resolve_events_with_state_map
logger = logging.getLogger(__name__) logger = logging.getLogger(__name__)
@ -573,294 +572,3 @@ def _make_state_cache_entry(
prev_group=prev_group, prev_group=prev_group,
delta_ids=delta_ids, delta_ids=delta_ids,
) )
def _ordered_events(events):
def key_func(e):
return -int(e.depth), hashlib.sha1(e.event_id.encode('ascii')).hexdigest()
return sorted(events, key=key_func)
def resolve_events_with_state_map(state_sets, state_map):
"""
Args:
state_sets(list): List of dicts of (type, state_key) -> event_id,
which are the different state groups to resolve.
state_map(dict): a dict from event_id to event, for all events in
state_sets.
Returns
dict[(str, str), str]:
a map from (type, state_key) to event_id.
"""
if len(state_sets) == 1:
return state_sets[0]
unconflicted_state, conflicted_state = _seperate(
state_sets,
)
auth_events = _create_auth_events_from_maps(
unconflicted_state, conflicted_state, state_map
)
return _resolve_with_state(
unconflicted_state, conflicted_state, auth_events, state_map
)
def _seperate(state_sets):
"""Takes the state_sets and figures out which keys are conflicted and
which aren't. i.e., which have multiple different event_ids associated
with them in different state sets.
Args:
state_sets(iterable[dict[(str, str), str]]):
List of dicts of (type, state_key) -> event_id, which are the
different state groups to resolve.
Returns:
(dict[(str, str), str], dict[(str, str), set[str]]):
A tuple of (unconflicted_state, conflicted_state), where:
unconflicted_state is a dict mapping (type, state_key)->event_id
for unconflicted state keys.
conflicted_state is a dict mapping (type, state_key) to a set of
event ids for conflicted state keys.
"""
state_set_iterator = iter(state_sets)
unconflicted_state = dict(next(state_set_iterator))
conflicted_state = {}
for state_set in state_set_iterator:
for key, value in iteritems(state_set):
# Check if there is an unconflicted entry for the state key.
unconflicted_value = unconflicted_state.get(key)
if unconflicted_value is None:
# There isn't an unconflicted entry so check if there is a
# conflicted entry.
ls = conflicted_state.get(key)
if ls is None:
# There wasn't a conflicted entry so haven't seen this key before.
# Therefore it isn't conflicted yet.
unconflicted_state[key] = value
else:
# This key is already conflicted, add our value to the conflict set.
ls.add(value)
elif unconflicted_value != value:
# If the unconflicted value is not the same as our value then we
# have a new conflict. So move the key from the unconflicted_state
# to the conflicted state.
conflicted_state[key] = {value, unconflicted_value}
unconflicted_state.pop(key, None)
return unconflicted_state, conflicted_state
@defer.inlineCallbacks
def resolve_events_with_factory(state_sets, event_map, state_map_factory):
"""
Args:
state_sets(list): List of dicts of (type, state_key) -> event_id,
which are the different state groups to resolve.
event_map(dict[str,FrozenEvent]|None):
a dict from event_id to event, for any events that we happen to
have in flight (eg, those currently being persisted). This will be
used as a starting point fof finding the state we need; any missing
events will be requested via state_map_factory.
If None, all events will be fetched via state_map_factory.
state_map_factory(func): will be called
with a list of event_ids that are needed, and should return with
a Deferred of dict of event_id to event.
Returns
Deferred[dict[(str, str), str]]:
a map from (type, state_key) to event_id.
"""
if len(state_sets) == 1:
defer.returnValue(state_sets[0])
unconflicted_state, conflicted_state = _seperate(
state_sets,
)
needed_events = set(
event_id
for event_ids in itervalues(conflicted_state)
for event_id in event_ids
)
if event_map is not None:
needed_events -= set(iterkeys(event_map))
logger.info("Asking for %d conflicted events", len(needed_events))
# dict[str, FrozenEvent]: a map from state event id to event. Only includes
# the state events which are in conflict (and those in event_map)
state_map = yield state_map_factory(needed_events)
if event_map is not None:
state_map.update(event_map)
# get the ids of the auth events which allow us to authenticate the
# conflicted state, picking only from the unconflicting state.
#
# dict[(str, str), str]: a map from state key to event id
auth_events = _create_auth_events_from_maps(
unconflicted_state, conflicted_state, state_map
)
new_needed_events = set(itervalues(auth_events))
new_needed_events -= needed_events
if event_map is not None:
new_needed_events -= set(iterkeys(event_map))
logger.info("Asking for %d auth events", len(new_needed_events))
state_map_new = yield state_map_factory(new_needed_events)
state_map.update(state_map_new)
defer.returnValue(_resolve_with_state(
unconflicted_state, conflicted_state, auth_events, state_map
))
def _create_auth_events_from_maps(unconflicted_state, conflicted_state, state_map):
auth_events = {}
for event_ids in itervalues(conflicted_state):
for event_id in event_ids:
if event_id in state_map:
keys = event_auth.auth_types_for_event(state_map[event_id])
for key in keys:
if key not in auth_events:
event_id = unconflicted_state.get(key, None)
if event_id:
auth_events[key] = event_id
return auth_events
def _resolve_with_state(unconflicted_state_ids, conflicted_state_ids, auth_event_ids,
state_map):
conflicted_state = {}
for key, event_ids in iteritems(conflicted_state_ids):
events = [state_map[ev_id] for ev_id in event_ids if ev_id in state_map]
if len(events) > 1:
conflicted_state[key] = events
elif len(events) == 1:
unconflicted_state_ids[key] = events[0].event_id
auth_events = {
key: state_map[ev_id]
for key, ev_id in iteritems(auth_event_ids)
if ev_id in state_map
}
try:
resolved_state = _resolve_state_events(
conflicted_state, auth_events
)
except Exception:
logger.exception("Failed to resolve state")
raise
new_state = unconflicted_state_ids
for key, event in iteritems(resolved_state):
new_state[key] = event.event_id
return new_state
def _resolve_state_events(conflicted_state, auth_events):
""" This is where we actually decide which of the conflicted state to
use.
We resolve conflicts in the following order:
1. power levels
2. join rules
3. memberships
4. other events.
"""
resolved_state = {}
if POWER_KEY in conflicted_state:
events = conflicted_state[POWER_KEY]
logger.debug("Resolving conflicted power levels %r", events)
resolved_state[POWER_KEY] = _resolve_auth_events(
events, auth_events)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key[0] == EventTypes.JoinRules:
logger.debug("Resolving conflicted join rules %r", events)
resolved_state[key] = _resolve_auth_events(
events,
auth_events
)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key[0] == EventTypes.Member:
logger.debug("Resolving conflicted member lists %r", events)
resolved_state[key] = _resolve_auth_events(
events,
auth_events
)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key not in resolved_state:
logger.debug("Resolving conflicted state %r:%r", key, events)
resolved_state[key] = _resolve_normal_events(
events, auth_events
)
return resolved_state
def _resolve_auth_events(events, auth_events):
reverse = [i for i in reversed(_ordered_events(events))]
auth_keys = set(
key
for event in events
for key in event_auth.auth_types_for_event(event)
)
new_auth_events = {}
for key in auth_keys:
auth_event = auth_events.get(key, None)
if auth_event:
new_auth_events[key] = auth_event
auth_events = new_auth_events
prev_event = reverse[0]
for event in reverse[1:]:
auth_events[(prev_event.type, prev_event.state_key)] = prev_event
try:
# The signatures have already been checked at this point
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
prev_event = event
except AuthError:
return prev_event
return event
def _resolve_normal_events(events, auth_events):
for event in _ordered_events(events):
try:
# The signatures have already been checked at this point
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
return event
except AuthError:
pass
# Use the last event (the one with the least depth) if they all fail
# the auth check.
return event

321
synapse/state/v1.py Normal file
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@ -0,0 +1,321 @@
# -*- coding: utf-8 -*-
# Copyright 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 hashlib
import logging
from six import iteritems, iterkeys, itervalues
from twisted.internet import defer
from synapse import event_auth
from synapse.api.constants import EventTypes
from synapse.api.errors import AuthError
logger = logging.getLogger(__name__)
POWER_KEY = (EventTypes.PowerLevels, "")
def resolve_events_with_state_map(state_sets, state_map):
"""
Args:
state_sets(list): List of dicts of (type, state_key) -> event_id,
which are the different state groups to resolve.
state_map(dict): a dict from event_id to event, for all events in
state_sets.
Returns
dict[(str, str), str]:
a map from (type, state_key) to event_id.
"""
if len(state_sets) == 1:
return state_sets[0]
unconflicted_state, conflicted_state = _seperate(
state_sets,
)
auth_events = _create_auth_events_from_maps(
unconflicted_state, conflicted_state, state_map
)
return _resolve_with_state(
unconflicted_state, conflicted_state, auth_events, state_map
)
@defer.inlineCallbacks
def resolve_events_with_factory(state_sets, event_map, state_map_factory):
"""
Args:
state_sets(list): List of dicts of (type, state_key) -> event_id,
which are the different state groups to resolve.
event_map(dict[str,FrozenEvent]|None):
a dict from event_id to event, for any events that we happen to
have in flight (eg, those currently being persisted). This will be
used as a starting point fof finding the state we need; any missing
events will be requested via state_map_factory.
If None, all events will be fetched via state_map_factory.
state_map_factory(func): will be called
with a list of event_ids that are needed, and should return with
a Deferred of dict of event_id to event.
Returns
Deferred[dict[(str, str), str]]:
a map from (type, state_key) to event_id.
"""
if len(state_sets) == 1:
defer.returnValue(state_sets[0])
unconflicted_state, conflicted_state = _seperate(
state_sets,
)
needed_events = set(
event_id
for event_ids in itervalues(conflicted_state)
for event_id in event_ids
)
if event_map is not None:
needed_events -= set(iterkeys(event_map))
logger.info("Asking for %d conflicted events", len(needed_events))
# dict[str, FrozenEvent]: a map from state event id to event. Only includes
# the state events which are in conflict (and those in event_map)
state_map = yield state_map_factory(needed_events)
if event_map is not None:
state_map.update(event_map)
# get the ids of the auth events which allow us to authenticate the
# conflicted state, picking only from the unconflicting state.
#
# dict[(str, str), str]: a map from state key to event id
auth_events = _create_auth_events_from_maps(
unconflicted_state, conflicted_state, state_map
)
new_needed_events = set(itervalues(auth_events))
new_needed_events -= needed_events
if event_map is not None:
new_needed_events -= set(iterkeys(event_map))
logger.info("Asking for %d auth events", len(new_needed_events))
state_map_new = yield state_map_factory(new_needed_events)
state_map.update(state_map_new)
defer.returnValue(_resolve_with_state(
unconflicted_state, conflicted_state, auth_events, state_map
))
def _seperate(state_sets):
"""Takes the state_sets and figures out which keys are conflicted and
which aren't. i.e., which have multiple different event_ids associated
with them in different state sets.
Args:
state_sets(iterable[dict[(str, str), str]]):
List of dicts of (type, state_key) -> event_id, which are the
different state groups to resolve.
Returns:
(dict[(str, str), str], dict[(str, str), set[str]]):
A tuple of (unconflicted_state, conflicted_state), where:
unconflicted_state is a dict mapping (type, state_key)->event_id
for unconflicted state keys.
conflicted_state is a dict mapping (type, state_key) to a set of
event ids for conflicted state keys.
"""
state_set_iterator = iter(state_sets)
unconflicted_state = dict(next(state_set_iterator))
conflicted_state = {}
for state_set in state_set_iterator:
for key, value in iteritems(state_set):
# Check if there is an unconflicted entry for the state key.
unconflicted_value = unconflicted_state.get(key)
if unconflicted_value is None:
# There isn't an unconflicted entry so check if there is a
# conflicted entry.
ls = conflicted_state.get(key)
if ls is None:
# There wasn't a conflicted entry so haven't seen this key before.
# Therefore it isn't conflicted yet.
unconflicted_state[key] = value
else:
# This key is already conflicted, add our value to the conflict set.
ls.add(value)
elif unconflicted_value != value:
# If the unconflicted value is not the same as our value then we
# have a new conflict. So move the key from the unconflicted_state
# to the conflicted state.
conflicted_state[key] = {value, unconflicted_value}
unconflicted_state.pop(key, None)
return unconflicted_state, conflicted_state
def _create_auth_events_from_maps(unconflicted_state, conflicted_state, state_map):
auth_events = {}
for event_ids in itervalues(conflicted_state):
for event_id in event_ids:
if event_id in state_map:
keys = event_auth.auth_types_for_event(state_map[event_id])
for key in keys:
if key not in auth_events:
event_id = unconflicted_state.get(key, None)
if event_id:
auth_events[key] = event_id
return auth_events
def _resolve_with_state(unconflicted_state_ids, conflicted_state_ids, auth_event_ids,
state_map):
conflicted_state = {}
for key, event_ids in iteritems(conflicted_state_ids):
events = [state_map[ev_id] for ev_id in event_ids if ev_id in state_map]
if len(events) > 1:
conflicted_state[key] = events
elif len(events) == 1:
unconflicted_state_ids[key] = events[0].event_id
auth_events = {
key: state_map[ev_id]
for key, ev_id in iteritems(auth_event_ids)
if ev_id in state_map
}
try:
resolved_state = _resolve_state_events(
conflicted_state, auth_events
)
except Exception:
logger.exception("Failed to resolve state")
raise
new_state = unconflicted_state_ids
for key, event in iteritems(resolved_state):
new_state[key] = event.event_id
return new_state
def _resolve_state_events(conflicted_state, auth_events):
""" This is where we actually decide which of the conflicted state to
use.
We resolve conflicts in the following order:
1. power levels
2. join rules
3. memberships
4. other events.
"""
resolved_state = {}
if POWER_KEY in conflicted_state:
events = conflicted_state[POWER_KEY]
logger.debug("Resolving conflicted power levels %r", events)
resolved_state[POWER_KEY] = _resolve_auth_events(
events, auth_events)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key[0] == EventTypes.JoinRules:
logger.debug("Resolving conflicted join rules %r", events)
resolved_state[key] = _resolve_auth_events(
events,
auth_events
)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key[0] == EventTypes.Member:
logger.debug("Resolving conflicted member lists %r", events)
resolved_state[key] = _resolve_auth_events(
events,
auth_events
)
auth_events.update(resolved_state)
for key, events in iteritems(conflicted_state):
if key not in resolved_state:
logger.debug("Resolving conflicted state %r:%r", key, events)
resolved_state[key] = _resolve_normal_events(
events, auth_events
)
return resolved_state
def _resolve_auth_events(events, auth_events):
reverse = [i for i in reversed(_ordered_events(events))]
auth_keys = set(
key
for event in events
for key in event_auth.auth_types_for_event(event)
)
new_auth_events = {}
for key in auth_keys:
auth_event = auth_events.get(key, None)
if auth_event:
new_auth_events[key] = auth_event
auth_events = new_auth_events
prev_event = reverse[0]
for event in reverse[1:]:
auth_events[(prev_event.type, prev_event.state_key)] = prev_event
try:
# The signatures have already been checked at this point
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
prev_event = event
except AuthError:
return prev_event
return event
def _resolve_normal_events(events, auth_events):
for event in _ordered_events(events):
try:
# The signatures have already been checked at this point
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
return event
except AuthError:
pass
# Use the last event (the one with the least depth) if they all fail
# the auth check.
return event
def _ordered_events(events):
def key_func(e):
return -int(e.depth), hashlib.sha1(e.event_id.encode('ascii')).hexdigest()
return sorted(events, key=key_func)