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Diffstat (limited to '')
| -rw-r--r-- | synapse/storage/state.py | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/synapse/storage/state.py b/synapse/storage/state.py new file mode 100644 index 0000000000..55ea567793 --- /dev/null +++ b/synapse/storage/state.py @@ -0,0 +1,127 @@ +# -*- coding: utf-8 -*- +# Copyright 2014 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. + +from ._base import SQLBaseStore + + +class StateStore(SQLBaseStore): + """ Keeps track of the state at a given event. + + This is done by the concept of `state groups`. Every event is a assigned + a state group (identified by an arbitrary string), which references a + collection of state events. The current state of an event is then the + collection of state events referenced by the event's state group. + + Hence, every change in the current state causes a new state group to be + generated. However, if no change happens (e.g., if we get a message event + with only one parent it inherits the state group from its parent.) + + There are three tables: + * `state_groups`: Stores group name, first event with in the group and + room id. + * `event_to_state_groups`: Maps events to state groups. + * `state_groups_state`: Maps state group to state events. + """ + + def get_state_groups(self, event_ids): + """ Get the state groups for the given list of event_ids + + The return value is a dict mapping group names to lists of events. + """ + + def f(txn): + groups = set() + for event_id in event_ids: + group = self._simple_select_one_onecol_txn( + txn, + table="event_to_state_groups", + keyvalues={"event_id": event_id}, + retcol="state_group", + allow_none=True, + ) + if group: + groups.add(group) + + res = {} + for group in groups: + state_ids = self._simple_select_onecol_txn( + txn, + table="state_groups_state", + keyvalues={"state_group": group}, + retcol="event_id", + ) + state = [] + for state_id in state_ids: + s = self._get_events_txn( + txn, + [state_id], + ) + if s: + state.extend(s) + + res[group] = state + + return res + + return self.runInteraction( + "get_state_groups", + f, + ) + + def store_state_groups(self, event): + return self.runInteraction( + "store_state_groups", + self._store_state_groups_txn, event + ) + + def _store_state_groups_txn(self, txn, event): + if not event.state_events: + return + + state_group = event.state_group + if not state_group: + state_group = self._simple_insert_txn( + txn, + table="state_groups", + values={ + "room_id": event.room_id, + "event_id": event.event_id, + }, + or_ignore=True, + ) + + for state in event.state_events.values(): + self._simple_insert_txn( + txn, + table="state_groups_state", + values={ + "state_group": state_group, + "room_id": state.room_id, + "type": state.type, + "state_key": state.state_key, + "event_id": state.event_id, + }, + or_ignore=True, + ) + + self._simple_insert_txn( + txn, + table="event_to_state_groups", + values={ + "state_group": state_group, + "event_id": event.event_id, + }, + or_replace=True, + ) |