128 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
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| # Copyright 2014 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| from ._base import SQLBaseStore
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| 
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| 
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| class StateStore(SQLBaseStore):
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|     """ Keeps track of the state at a given event.
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| 
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|     This is done by the concept of `state groups`. Every event is a assigned
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|     a state group (identified by an arbitrary string), which references a
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|     collection of state events. The current state of an event is then the
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|     collection of state events referenced by the event's state group.
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| 
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|     Hence, every change in the current state causes a new state group to be
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|     generated. However, if no change happens (e.g., if we get a message event
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|     with only one parent it inherits the state group from its parent.)
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| 
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|     There are three tables:
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|       * `state_groups`: Stores group name, first event with in the group and
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|         room id.
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|       * `event_to_state_groups`: Maps events to state groups.
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|       * `state_groups_state`: Maps state group to state events.
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|     """
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| 
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|     def get_state_groups(self, event_ids):
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|         """ Get the state groups for the given list of event_ids
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| 
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|         The return value is a dict mapping group names to lists of events.
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|         """
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| 
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|         def f(txn):
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|             groups = set()
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|             for event_id in event_ids:
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|                 group = self._simple_select_one_onecol_txn(
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|                     txn,
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|                     table="event_to_state_groups",
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|                     keyvalues={"event_id": event_id},
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|                     retcol="state_group",
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|                     allow_none=True,
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|                 )
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|                 if group:
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|                     groups.add(group)
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| 
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|             res = {}
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|             for group in groups:
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|                 state_ids = self._simple_select_onecol_txn(
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|                     txn,
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|                     table="state_groups_state",
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|                     keyvalues={"state_group": group},
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|                     retcol="event_id",
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|                 )
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|                 state = []
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|                 for state_id in state_ids:
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|                     s = self._get_events_txn(
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|                         txn,
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|                         [state_id],
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|                     )
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|                     if s:
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|                         state.extend(s)
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| 
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|                 res[group] = state
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| 
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|             return res
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| 
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|         return self.runInteraction(
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|             "get_state_groups",
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|             f,
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|         )
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| 
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|     def store_state_groups(self, event):
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|         return self.runInteraction(
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|             "store_state_groups",
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|             self._store_state_groups_txn, event
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|         )
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| 
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|     def _store_state_groups_txn(self, txn, event):
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|         if not event.state_events:
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|             return
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| 
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|         state_group = event.state_group
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|         if not state_group:
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|             state_group = self._simple_insert_txn(
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|                 txn,
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|                 table="state_groups",
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|                 values={
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|                     "room_id": event.room_id,
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|                     "event_id": event.event_id,
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|                 },
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|                 or_ignore=True,
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|             )
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| 
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|             for state in event.state_events.values():
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|                 self._simple_insert_txn(
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|                     txn,
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|                     table="state_groups_state",
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|                     values={
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|                         "state_group": state_group,
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|                         "room_id": state.room_id,
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|                         "type": state.type,
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|                         "state_key": state.state_key,
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|                         "event_id": state.event_id,
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|                     },
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|                     or_ignore=True,
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|                 )
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| 
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|         self._simple_insert_txn(
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|             txn,
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|             table="event_to_state_groups",
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|             values={
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|                 "state_group": state_group,
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|                 "event_id": event.event_id,
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|             },
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|             or_replace=True,
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|         )
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