# Copyright 2022 The Matrix.org Foundation C.I.C.
#
# 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 typing import (
TYPE_CHECKING,
AbstractSet,
Any,
Awaitable,
Callable,
Collection,
Dict,
Iterable,
List,
Mapping,
Optional,
Tuple,
)
from synapse.api.constants import EventTypes
from synapse.events import EventBase
from synapse.logging.opentracing import tag_args, trace
from synapse.storage.roommember import ProfileInfo
from synapse.storage.util.partial_state_events_tracker import (
PartialCurrentStateTracker,
PartialStateEventsTracker,
)
from synapse.types import MutableStateMap, StateMap
from synapse.types.state import StateFilter
from synapse.util.cancellation import cancellable
if TYPE_CHECKING:
from synapse.server import HomeServer
from synapse.storage.databases import Databases
logger = logging.getLogger(__name__)
class StateStorageController:
"""High level interface to fetching state for an event, or the current state
in a room.
"""
def __init__(self, hs: "HomeServer", stores: "Databases"):
self._is_mine_id = hs.is_mine_id
self.stores = stores
self._partial_state_events_tracker = PartialStateEventsTracker(stores.main)
self._partial_state_room_tracker = PartialCurrentStateTracker(stores.main)
def notify_event_un_partial_stated(self, event_id: str) -> None:
self._partial_state_events_tracker.notify_un_partial_stated(event_id)
def notify_room_un_partial_stated(self, room_id: str) -> None:
"""Notify that the room no longer has any partial state.
Must be called after `DataStore.clear_partial_state_room`
"""
self._partial_state_room_tracker.notify_un_partial_stated(room_id)
async def get_state_group_delta(
self, state_group: int
) -> Tuple[Optional[int], Optional[StateMap[str]]]:
"""Given a state group try to return a previous group and a delta between
the old and the new.
Args:
state_group: The state group used to retrieve state deltas.
Returns:
A tuple of the previous group and a state map of the event IDs which
make up the delta between the old and new state groups.
"""
state_group_delta = await self.stores.state.get_state_group_delta(state_group)
return state_group_delta.prev_group, state_group_delta.delta_ids
async def get_state_groups_ids(
self, _room_id: str, event_ids: Collection[str], await_full_state: bool = True
) -> Dict[int, MutableStateMap[str]]:
"""Get the event IDs of all the state for the state groups for the given events
Args:
_room_id: id of the room for these events
event_ids: ids of the events
await_full_state: if `True`, will block if we do not yet have complete
state at these events.
Returns:
dict of state_group_id -> (dict of (type, state_key) -> event id)
Raises:
RuntimeError if we don't have a state group for one or more of the events
(ie they are outliers or unknown)
"""
if not event_ids:
return {}
event_to_groups = await self.get_state_group_for_events(
event_ids, await_full_state=await_full_state
)
groups = set(event_to_groups.values())
group_to_state = await self.stores.state._get_state_for_groups(groups)
return group_to_state
async def get_state_ids_for_group(
self, state_group: int, state_filter: Optional[StateFilter] = None
) -> StateMap[str]:
"""Get the event IDs of all the state in the given state group
Args:
state_group: A state group for which we want to get the state IDs.
state_filter: specifies the type of state event to fetch from DB, example: EventTypes.JoinRules
Returns:
Resolves to a map of (type, state_key) -> event_id
"""
group_to_state = await self.get_state_for_groups((state_group,), state_filter)
return group_to_state[state_group]
async def get_state_groups(
self, room_id: str, event_ids: Collection[str]
) -> Dict[int, List[EventBase]]:
"""Get the state groups for the given list of event_ids
Args:
room_id: ID of the room for these events.
event_ids: The event IDs to retrieve state for.
Returns:
dict of state_group_id -> list of state events.
"""
if not event_ids:
return {}
group_to_ids = await self.get_state_groups_ids(room_id, event_ids)
state_event_map = await self.stores.main.get_events(
[
ev_id
for group_ids in group_to_ids.values()
for ev_id in group_ids.values()
],
get_prev_content=False,
)
return {
group: [
state_event_map[v]
for v in event_id_map.values()
if v in state_event_map
]
for group, event_id_map in group_to_ids.items()
}
def _get_state_groups_from_groups(
self, groups: List[int], state_filter: StateFilter
) -> Awaitable[Dict[int, StateMap[str]]]:
"""Returns the state groups for a given set of groups, filtering on
types of state events.
Args:
groups: list of state group IDs to query
state_filter: The state filter used to fetch state
from the database.
Returns:
Dict of state group to state map.
"""
return self.stores.state._get_state_groups_from_groups(groups, state_filter)
@trace
async def get_state_for_events(
self, event_ids: Collection[str], state_filter: Optional[StateFilter] = None
) -> Dict[str, StateMap[EventBase]]:
"""Given a list of event_ids and type tuples, return a list of state
dicts for each event.
Args:
event_ids: The events to fetch the state of.
state_filter: The state filter used to fetch state.
Returns:
A dict of (event_id) -> (type, state_key) -> [state_events]
Raises:
RuntimeError if we don't have a state group for one or more of the events
(ie they are outliers or unknown)
"""
await_full_state = True
if state_filter and not state_filter.must_await_full_state(self._is_mine_id):
await_full_state = False
event_to_groups = await self.get_state_group_for_events(
event_ids, await_full_state=await_full_state
)
groups = set(event_to_groups.values())
group_to_state = await self.stores.state._get_state_for_groups(
groups, state_filter or StateFilter.all()
)
state_event_map = await self.stores.main.get_events(
[ev_id for sd in group_to_state.values() for ev_id in sd.values()],
get_prev_content=False,
)
event_to_state = {
event_id: {
k: state_event_map[v]
for k, v in group_to_state[group].items()
if v in state_event_map
}
for event_id, group in event_to_groups.items()
}
return {event: event_to_state[event] for event in event_ids}
@trace
@tag_args
@cancellable
async def get_state_ids_for_events(
self,
event_ids: Collection[str],
state_filter: Optional[StateFilter] = None,
await_full_state: bool = True,
) -> Dict[str, StateMap[str]]:
"""
Get the state dicts corresponding to a list of events, containing the event_ids
of the state events (as opposed to the events themselves)
Args:
event_ids: events whose state should be returned
state_filter: The state filter used to fetch state from the database.
await_full_state: if `True`, will block if we do not yet have complete state
at these events and `state_filter` is not satisfied by partial state.
Defaults to `True`.
Returns:
A dict from event_id -> (type, state_key) -> event_id
Raises:
RuntimeError if we don't have a state group for one or more of the events
(ie they are outliers or unknown)
"""
if (
await_full_state
and state_filter
and not state_filter.must_await_full_state(self._is_mine_id)
):
# Full state is not required if the state filter is restrictive enough.
await_full_state = False
event_to_groups = await self.get_state_group_for_events(
event_ids, await_full_state=await_full_state
)
groups = set(event_to_groups.values())
group_to_state = await self.stores.state._get_state_for_groups(
groups, state_filter or StateFilter.all()
)
event_to_state = {
event_id: group_to_state[group]
for event_id, group in event_to_groups.items()
}
return {event: event_to_state[event] for event in event_ids}
async def get_state_for_event(
self, event_id: str, state_filter: Optional[StateFilter] = None
) -> StateMap[EventBase]:
"""
Get the state dict corresponding to a particular event
Args:
event_id: event whose state should be returned
state_filter: The state filter used to fetch state from the database.
Returns:
A dict from (type, state_key) -> state_event
Raises:
RuntimeError if we don't have a state group for the event (ie it is an
outlier or is unknown)
"""
state_map = await self.get_state_for_events(
[event_id], state_filter or StateFilter.all()
)
return state_map[event_id]
@trace
async def get_state_ids_for_event(
self,
event_id: str,
state_filter: Optional[StateFilter] = None,
await_full_state: bool = True,
) -> StateMap[str]:
"""
Get the state dict corresponding to a particular event
Args:
event_id: event whose state should be returned
state_filter: The state filter used to fetch state from the database.
await_full_state: if `True`, will block if we do not yet have complete state
at the event and `state_filter` is not satisfied by partial state.
Defaults to `True`.
Returns:
A dict from (type, state_key) -> state_event_id
Raises:
RuntimeError if we don't have a state group for the event (ie it is an
outlier or is unknown)
"""
state_map = await self.get_state_ids_for_events(
[event_id],
state_filter or StateFilter.all(),
await_full_state=await_full_state,
)
return state_map[event_id]
def get_state_for_groups(
self, groups: Iterable[int], state_filter: Optional[StateFilter] = None
) -> Awaitable[Dict[int, MutableStateMap[str]]]:
"""Gets the state at each of a list of state groups, optionally
filtering by type/state_key
Args:
groups: list of state groups for which we want to get the state.
state_filter: The state filter used to fetch state.
from the database.
Returns:
Dict of state group to state map.
"""
return self.stores.state._get_state_for_groups(
groups, state_filter or StateFilter.all()
)
@trace
@tag_args
@cancellable
async def get_state_group_for_events(
self,
event_ids: Collection[str],
await_full_state: bool = True,
) -> Mapping[str, int]:
"""Returns mapping event_id -> state_group
Args:
event_ids: events to get state groups for
await_full_state: if true, will block if we do not yet have complete
state at these events.
Raises:
RuntimeError if we don't have a state group for one or more of the events
(ie. they are outliers or unknown)
"""
if await_full_state:
await self._partial_state_events_tracker.await_full_state(event_ids)
return await self.stores.main._get_state_group_for_events(event_ids)
async def store_state_group(
self,
event_id: str,
room_id: str,
prev_group: Optional[int],
delta_ids: Optional[StateMap[str]],
current_state_ids: Optional[StateMap[str]],
) -> int:
"""Store a new set of state, returning a newly assigned state group.
Args:
event_id: The event ID for which the state was calculated.
room_id: ID of the room for which the state was calculated.
prev_group: A previous state group for the room, optional.
delta_ids: The delta between state at `prev_group` and
`current_state_ids`, if `prev_group` was given. Same format as
`current_state_ids`.
current_state_ids: The state to store. Map of (type, state_key)
to event_id.
Returns:
The state group ID
"""
return await self.stores.state.store_state_group(
event_id, room_id, prev_group, delta_ids, current_state_ids
)
@cancellable
async def get_current_state_ids(
self,
room_id: str,
state_filter: Optional[StateFilter] = None,
await_full_state: bool = True,
on_invalidate: Optional[Callable[[], None]] = None,
) -> StateMap[str]:
"""Get the current state event ids for a room based on the
current_state_events table.
If a state filter is given (that is not `StateFilter.all()`) the query
result is *not* cached.
Args:
room_id: The room to get the state IDs of. state_filter: The state
filter used to fetch state from the
database.
await_full_state: if true, will block if we do not yet have complete
state for the room.
on_invalidate: Callback for when the `get_current_state_ids` cache
for the room gets invalidated.
Returns:
The current state of the room.
"""
if await_full_state and (
not state_filter or state_filter.must_await_full_state(self._is_mine_id)
):
await self._partial_state_room_tracker.await_full_state(room_id)
if state_filter and not state_filter.is_full():
return await self.stores.main.get_partial_filtered_current_state_ids(
room_id, state_filter
)
else:
return await self.stores.main.get_partial_current_state_ids(
room_id, on_invalidate=on_invalidate
)
async def get_canonical_alias_for_room(self, room_id: str) -> Optional[str]:
"""Get canonical alias for room, if any
Args:
room_id: The room ID
Returns:
The canonical alias, if any
"""
state = await self.get_current_state_ids(
room_id, StateFilter.from_types([(EventTypes.CanonicalAlias, "")])
)
event_id = state.get((EventTypes.CanonicalAlias, ""))
if not event_id:
return None
event = await self.stores.main.get_event(event_id, allow_none=True)
if not event:
return None
return event.content.get("canonical_alias")
async def get_current_state_deltas(
self, prev_stream_id: int, max_stream_id: int
) -> Tuple[int, List[Dict[str, Any]]]:
"""Fetch a list of room state changes since the given stream id
Each entry in the result contains the following fields:
- stream_id (int)
- room_id (str)
- type (str): event type
- state_key (str):
- event_id (str|None): new event_id for this state key. None if the
state has been deleted.
- prev_event_id (str|None): previous event_id for this state key. None
if it's new state.
Args:
prev_stream_id: point to get changes since (exclusive)
max_stream_id: the point that we know has been correctly persisted
- ie, an upper limit to return changes from.
Returns:
A tuple consisting of:
- the stream id which these results go up to
- list of current_state_delta_stream rows. If it is empty, we are
up to date.
"""
# FIXME(faster_joins): what do we do here?
# https://github.com/matrix-org/synapse/issues/13008
return await self.stores.main.get_partial_current_state_deltas(
prev_stream_id, max_stream_id
)
@trace
async def get_current_state(
self, room_id: str, state_filter: Optional[StateFilter] = None
) -> StateMap[EventBase]:
"""Same as `get_current_state_ids` but also fetches the events"""
state_map_ids = await self.get_current_state_ids(room_id, state_filter)
event_map = await self.stores.main.get_events(list(state_map_ids.values()))
state_map = {}
for key, event_id in state_map_ids.items():
event = event_map.get(event_id)
if event:
state_map[key] = event
return state_map
async def get_current_state_event(
self, room_id: str, event_type: str, state_key: str
) -> Optional[EventBase]:
"""Get the current state event for the given type/state_key."""
key = (event_type, state_key)
state_map = await self.get_current_state(
room_id, StateFilter.from_types((key,))
)
return state_map.get(key)
async def get_current_hosts_in_room(self, room_id: str) -> AbstractSet[str]:
"""Get current hosts in room based on current state.
Blocks until we have full state for the given room. This only happens for rooms
with partial state.
"""
await self._partial_state_room_tracker.await_full_state(room_id)
return await self.stores.main.get_current_hosts_in_room(room_id)
async def get_current_hosts_in_room_ordered(self, room_id: str) -> List[str]:
"""Get current hosts in room based on current state.
Blocks until we have full state for the given room. This only happens for rooms
with partial state.
Returns:
A list of hosts in the room, sorted by longest in the room first. (aka.
sorted by join with the lowest depth first).
"""
await self._partial_state_room_tracker.await_full_state(room_id)
return await self.stores.main.get_current_hosts_in_room_ordered(room_id)
async def get_current_hosts_in_room_or_partial_state_approximation(
self, room_id: str
) -> Collection[str]:
"""Get approximation of current hosts in room based on current state.
For rooms with full state, this is equivalent to `get_current_hosts_in_room`,
with the same order of results.
For rooms with partial state, no blocking occurs. Instead, the list of hosts
in the room at the time of joining is combined with the list of hosts which
joined the room afterwards. The returned list may include hosts that are not
actually in the room and exclude hosts that are in the room, since we may
calculate state incorrectly during the partial state phase. The order of results
is arbitrary for rooms with partial state.
"""
# We have to read this list first to mitigate races with un-partial stating.
hosts_at_join = await self.stores.main.get_partial_state_servers_at_join(
room_id
)
if hosts_at_join is None:
hosts_at_join = frozenset()
hosts_from_state = await self.stores.main.get_current_hosts_in_room(room_id)
hosts = set(hosts_at_join)
hosts.update(hosts_from_state)
return hosts
async def get_users_in_room_with_profiles(
self, room_id: str
) -> Mapping[str, ProfileInfo]:
"""
Get the current users in the room with their profiles.
If the room is currently partial-stated, this will block until the room has
full state.
"""
await self._partial_state_room_tracker.await_full_state(room_id)
return await self.stores.main.get_users_in_room_with_profiles(room_id)