diff --git a/synapse/state.py b/synapse/state.py
index 9e624b4937..932f602508 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -58,7 +58,11 @@ class _StateCacheEntry(object):
__slots__ = ["state", "state_group", "state_id", "prev_group", "delta_ids"]
def __init__(self, state, state_group, prev_group=None, delta_ids=None):
+ # dict[(str, str), str] map from (type, state_key) to event_id
self.state = frozendict(state)
+
+ # the ID of a state group if one and only one is involved.
+ # otherwise, None otherwise?
self.state_group = state_group
self.prev_group = prev_group
@@ -81,31 +85,19 @@ class _StateCacheEntry(object):
class StateHandler(object):
- """ Responsible for doing state conflict resolution.
+ """Fetches bits of state from the stores, and does state resolution
+ where necessary
"""
def __init__(self, hs):
self.clock = hs.get_clock()
self.store = hs.get_datastore()
self.hs = hs
-
- # dict of set of event_ids -> _StateCacheEntry.
- self._state_cache = None
- self.resolve_linearizer = Linearizer(name="state_resolve_lock")
+ self._state_resolution_handler = hs.get_state_resolution_handler()
def start_caching(self):
- logger.debug("start_caching")
-
- self._state_cache = ExpiringCache(
- cache_name="state_cache",
- clock=self.clock,
- max_len=SIZE_OF_CACHE,
- expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
- iterable=True,
- reset_expiry_on_get=True,
- )
-
- self._state_cache.start()
+ # TODO: remove this shim
+ self._state_resolution_handler.start_caching()
@defer.inlineCallbacks
def get_current_state(self, room_id, event_type=None, state_key="",
@@ -127,7 +119,7 @@ class StateHandler(object):
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
logger.debug("calling resolve_state_groups from get_current_state")
- ret = yield self.resolve_state_groups(room_id, latest_event_ids)
+ ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
state = ret.state
if event_type:
@@ -146,19 +138,27 @@ class StateHandler(object):
defer.returnValue(state)
@defer.inlineCallbacks
- def get_current_state_ids(self, room_id, event_type=None, state_key="",
- latest_event_ids=None):
+ def get_current_state_ids(self, room_id, latest_event_ids=None):
+ """Get the current state, or the state at a set of events, for a room
+
+ Args:
+ room_id (str):
+
+ latest_event_ids (iterable[str]|None): if given, the forward
+ extremities to resolve. If None, we look them up from the
+ database (via a cache)
+
+ Returns:
+ Deferred[dict[(str, str), str)]]: the state dict, mapping from
+ (event_type, state_key) -> event_id
+ """
if not latest_event_ids:
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
logger.debug("calling resolve_state_groups from get_current_state_ids")
- ret = yield self.resolve_state_groups(room_id, latest_event_ids)
+ ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
state = ret.state
- if event_type:
- defer.returnValue(state.get((event_type, state_key)))
- return
-
defer.returnValue(state)
@defer.inlineCallbacks
@@ -166,7 +166,7 @@ class StateHandler(object):
if not latest_event_ids:
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
logger.debug("calling resolve_state_groups from get_current_user_in_room")
- entry = yield self.resolve_state_groups(room_id, latest_event_ids)
+ entry = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
joined_users = yield self.store.get_joined_users_from_state(room_id, entry)
defer.returnValue(joined_users)
@@ -175,7 +175,7 @@ class StateHandler(object):
if not latest_event_ids:
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
logger.debug("calling resolve_state_groups from get_current_hosts_in_room")
- entry = yield self.resolve_state_groups(room_id, latest_event_ids)
+ entry = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
joined_hosts = yield self.store.get_joined_hosts(room_id, entry)
defer.returnValue(joined_hosts)
@@ -183,8 +183,15 @@ class StateHandler(object):
def compute_event_context(self, event, old_state=None):
"""Build an EventContext structure for the event.
+ This works out what the current state should be for the event, and
+ generates a new state group if necessary.
+
Args:
event (synapse.events.EventBase):
+ old_state (dict|None): The state at the event if it can't be
+ calculated from existing events. This is normally only specified
+ when receiving an event from federation where we don't have the
+ prev events for, e.g. when backfilling.
Returns:
synapse.events.snapshot.EventContext:
"""
@@ -208,15 +215,22 @@ class StateHandler(object):
context.current_state_ids = {}
context.prev_state_ids = {}
context.prev_state_events = []
- context.state_group = self.store.get_next_state_group()
+
+ # We don't store state for outliers, so we don't generate a state
+ # froup for it.
+ context.state_group = None
+
defer.returnValue(context)
if old_state:
+ # We already have the state, so we don't need to calculate it.
+ # Let's just correctly fill out the context and create a
+ # new state group for it.
+
context = EventContext()
context.prev_state_ids = {
(s.type, s.state_key): s.event_id for s in old_state
}
- context.state_group = self.store.get_next_state_group()
if event.is_state():
key = (event.type, event.state_key)
@@ -229,11 +243,19 @@ class StateHandler(object):
else:
context.current_state_ids = context.prev_state_ids
+ context.state_group = yield self.store.store_state_group(
+ event.event_id,
+ event.room_id,
+ prev_group=None,
+ delta_ids=None,
+ current_state_ids=context.current_state_ids,
+ )
+
context.prev_state_events = []
defer.returnValue(context)
logger.debug("calling resolve_state_groups from compute_event_context")
- entry = yield self.resolve_state_groups(
+ entry = yield self.resolve_state_groups_for_events(
event.room_id, [e for e, _ in event.prev_events],
)
@@ -242,7 +264,8 @@ class StateHandler(object):
context = EventContext()
context.prev_state_ids = curr_state
if event.is_state():
- context.state_group = self.store.get_next_state_group()
+ # If this is a state event then we need to create a new state
+ # group for the state after this event.
key = (event.type, event.state_key)
if key in context.prev_state_ids:
@@ -253,38 +276,57 @@ class StateHandler(object):
context.current_state_ids[key] = event.event_id
if entry.state_group:
+ # If the state at the event has a state group assigned then
+ # we can use that as the prev group
context.prev_group = entry.state_group
context.delta_ids = {
key: event.event_id
}
elif entry.prev_group:
+ # If the state at the event only has a prev group, then we can
+ # use that as a prev group too.
context.prev_group = entry.prev_group
context.delta_ids = dict(entry.delta_ids)
context.delta_ids[key] = event.event_id
+
+ context.state_group = yield self.store.store_state_group(
+ event.event_id,
+ event.room_id,
+ prev_group=context.prev_group,
+ delta_ids=context.delta_ids,
+ current_state_ids=context.current_state_ids,
+ )
else:
+ context.current_state_ids = context.prev_state_ids
+ context.prev_group = entry.prev_group
+ context.delta_ids = entry.delta_ids
+
if entry.state_group is None:
- entry.state_group = self.store.get_next_state_group()
+ entry.state_group = yield self.store.store_state_group(
+ event.event_id,
+ event.room_id,
+ prev_group=entry.prev_group,
+ delta_ids=entry.delta_ids,
+ current_state_ids=context.current_state_ids,
+ )
entry.state_id = entry.state_group
context.state_group = entry.state_group
- context.current_state_ids = context.prev_state_ids
- context.prev_group = entry.prev_group
- context.delta_ids = entry.delta_ids
context.prev_state_events = []
defer.returnValue(context)
@defer.inlineCallbacks
- @log_function
- def resolve_state_groups(self, room_id, event_ids):
+ def resolve_state_groups_for_events(self, room_id, event_ids):
""" Given a list of event_ids this method fetches the state at each
event, resolves conflicts between them and returns them.
+ Args:
+ room_id (str):
+ event_ids (list[str]):
+
Returns:
- a Deferred tuple of (`state_group`, `state`, `prev_state`).
- `state_group` is the name of a state group if one and only one is
- involved. `state` is a map from (type, state_key) to event, and
- `prev_state` is a list of event ids.
+ Deferred[_StateCacheEntry]: resolved state
"""
logger.debug("resolve_state_groups event_ids %s", event_ids)
@@ -295,13 +337,7 @@ class StateHandler(object):
room_id, event_ids
)
- logger.debug(
- "resolve_state_groups state_groups %s",
- state_groups_ids.keys()
- )
-
- group_names = frozenset(state_groups_ids.keys())
- if len(group_names) == 1:
+ if len(state_groups_ids) == 1:
name, state_list = state_groups_ids.items().pop()
prev_group, delta_ids = yield self.store.get_state_group_delta(name)
@@ -313,6 +349,102 @@ class StateHandler(object):
delta_ids=delta_ids,
))
+ result = yield self._state_resolution_handler.resolve_state_groups(
+ room_id, state_groups_ids, None, self._state_map_factory,
+ )
+ defer.returnValue(result)
+
+ def _state_map_factory(self, ev_ids):
+ return self.store.get_events(
+ ev_ids, get_prev_content=False, check_redacted=False,
+ )
+
+ def resolve_events(self, state_sets, event):
+ logger.info(
+ "Resolving state for %s with %d groups", event.room_id, len(state_sets)
+ )
+ state_set_ids = [{
+ (ev.type, ev.state_key): ev.event_id
+ for ev in st
+ } for st in state_sets]
+
+ state_map = {
+ ev.event_id: ev
+ for st in state_sets
+ for ev in st
+ }
+
+ with Measure(self.clock, "state._resolve_events"):
+ new_state = resolve_events_with_state_map(state_set_ids, state_map)
+
+ new_state = {
+ key: state_map[ev_id] for key, ev_id in new_state.items()
+ }
+
+ return new_state
+
+
+class StateResolutionHandler(object):
+ """Responsible for doing state conflict resolution.
+
+ Note that the storage layer depends on this handler, so all functions must
+ be storage-independent.
+ """
+ def __init__(self, hs):
+ self.clock = hs.get_clock()
+
+ # dict of set of event_ids -> _StateCacheEntry.
+ self._state_cache = None
+ self.resolve_linearizer = Linearizer(name="state_resolve_lock")
+
+ def start_caching(self):
+ logger.debug("start_caching")
+
+ self._state_cache = ExpiringCache(
+ cache_name="state_cache",
+ clock=self.clock,
+ max_len=SIZE_OF_CACHE,
+ expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
+ iterable=True,
+ reset_expiry_on_get=True,
+ )
+
+ self._state_cache.start()
+
+ @defer.inlineCallbacks
+ @log_function
+ def resolve_state_groups(
+ self, room_id, state_groups_ids, event_map, state_map_factory,
+ ):
+ """Resolves conflicts between a set of state groups
+
+ Always generates a new state group (unless we hit the cache), so should
+ not be called for a single state group
+
+ Args:
+ room_id (str): room we are resolving for (used for logging)
+ state_groups_ids (dict[int, dict[(str, str), str]]):
+ map from state group id to the state in that state group
+ (where 'state' is a map from state key to event id)
+
+ 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.
+
+ Returns:
+ Deferred[_StateCacheEntry]: resolved state
+ """
+ logger.debug(
+ "resolve_state_groups state_groups %s",
+ state_groups_ids.keys()
+ )
+
+ group_names = frozenset(state_groups_ids.keys())
+
with (yield self.resolve_linearizer.queue(group_names)):
if self._state_cache is not None:
cache = self._state_cache.get(group_names, None)
@@ -341,17 +473,20 @@ class StateHandler(object):
if conflicted_state:
logger.info("Resolving conflicted state for %r", room_id)
with Measure(self.clock, "state._resolve_events"):
- new_state = yield resolve_events(
+ new_state = yield resolve_events_with_factory(
state_groups_ids.values(),
- state_map_factory=lambda ev_ids: self.store.get_events(
- ev_ids, get_prev_content=False, check_redacted=False,
- ),
+ event_map=event_map,
+ state_map_factory=state_map_factory,
)
else:
new_state = {
key: e_ids.pop() for key, e_ids in state.items()
}
+ # if the new state matches any of the input state groups, we can
+ # use that state group again. Otherwise we will generate a state_id
+ # which will be used as a cache key for future resolutions, but
+ # not get persisted.
state_group = None
new_state_event_ids = frozenset(new_state.values())
for sg, events in state_groups_ids.items():
@@ -388,30 +523,6 @@ class StateHandler(object):
defer.returnValue(cache)
- def resolve_events(self, state_sets, event):
- logger.info(
- "Resolving state for %s with %d groups", event.room_id, len(state_sets)
- )
- state_set_ids = [{
- (ev.type, ev.state_key): ev.event_id
- for ev in st
- } for st in state_sets]
-
- state_map = {
- ev.event_id: ev
- for st in state_sets
- for ev in st
- }
-
- with Measure(self.clock, "state._resolve_events"):
- new_state = resolve_events(state_set_ids, state_map)
-
- new_state = {
- key: state_map[ev_id] for key, ev_id in new_state.items()
- }
-
- return new_state
-
def _ordered_events(events):
def key_func(e):
@@ -420,19 +531,17 @@ def _ordered_events(events):
return sorted(events, key=key_func)
-def resolve_events(state_sets, state_map_factory):
+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_factory(dict|callable): If callable, then 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. Otherwise, should be
- a dict from event_id to event of all events in state_sets.
+ state_map(dict): a dict from event_id to event, for all events in
+ state_sets.
Returns
- dict[(str, str), synapse.events.FrozenEvent] is a map from
- (type, state_key) to event.
+ dict[(str, str), str]:
+ a map from (type, state_key) to event_id.
"""
if len(state_sets) == 1:
return state_sets[0]
@@ -441,13 +550,6 @@ def resolve_events(state_sets, state_map_factory):
state_sets,
)
- if callable(state_map_factory):
- return _resolve_with_state_fac(
- unconflicted_state, conflicted_state, state_map_factory
- )
-
- state_map = state_map_factory
-
auth_events = _create_auth_events_from_maps(
unconflicted_state, conflicted_state, state_map
)
@@ -461,6 +563,21 @@ 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(list[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.
"""
unconflicted_state = dict(state_sets[0])
conflicted_state = {}
@@ -491,19 +608,50 @@ def _seperate(state_sets):
@defer.inlineCallbacks
-def _resolve_with_state_fac(unconflicted_state, conflicted_state,
- state_map_factory):
+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 conflicted_state.itervalues()
for event_id in event_ids
)
+ if event_map is not None:
+ needed_events -= set(event_map.iterkeys())
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.
+ # 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.
@@ -515,6 +663,8 @@ def _resolve_with_state_fac(unconflicted_state, conflicted_state,
new_needed_events = set(auth_events.itervalues())
new_needed_events -= needed_events
+ if event_map is not None:
+ new_needed_events -= set(event_map.iterkeys())
logger.info("Asking for %d auth events", len(new_needed_events))
|
