From 8b309adb436c162510ed1402f33b8741d71fc058 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Tue, 8 Feb 2022 07:43:30 -0500 Subject: Fetch edits for multiple events in a single query. (#11660) This should reduce database usage when fetching bundled aggregations as the number of individual queries (and round trips to the database) are reduced. --- changelog.d/11660.misc | 1 + synapse/storage/databases/main/events.py | 4 +- synapse/storage/databases/main/relations.py | 150 ++++++++++++++++++---------- 3 files changed, 101 insertions(+), 54 deletions(-) create mode 100644 changelog.d/11660.misc diff --git a/changelog.d/11660.misc b/changelog.d/11660.misc new file mode 100644 index 0000000000..47e085e4d9 --- /dev/null +++ b/changelog.d/11660.misc @@ -0,0 +1 @@ +Improve performance when fetching bundled aggregations for multiple events. diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py index b804185c40..2e44c77715 100644 --- a/synapse/storage/databases/main/events.py +++ b/synapse/storage/databases/main/events.py @@ -1801,9 +1801,7 @@ class PersistEventsStore: ) if rel_type == RelationTypes.REPLACE: - txn.call_after( - self.store.get_applicable_edit.invalidate, (parent_id, event.room_id) - ) + txn.call_after(self.store.get_applicable_edit.invalidate, (parent_id,)) if rel_type == RelationTypes.THREAD: txn.call_after( diff --git a/synapse/storage/databases/main/relations.py b/synapse/storage/databases/main/relations.py index 37468a5183..6180b17296 100644 --- a/synapse/storage/databases/main/relations.py +++ b/synapse/storage/databases/main/relations.py @@ -13,12 +13,22 @@ # limitations under the License. import logging -from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Tuple, Union, cast +from typing import ( + TYPE_CHECKING, + Collection, + Dict, + Iterable, + List, + Optional, + Tuple, + Union, + cast, +) import attr from frozendict import frozendict -from synapse.api.constants import EventTypes, RelationTypes +from synapse.api.constants import RelationTypes from synapse.events import EventBase from synapse.storage._base import SQLBaseStore from synapse.storage.database import ( @@ -28,13 +38,14 @@ from synapse.storage.database import ( make_in_list_sql_clause, ) from synapse.storage.databases.main.stream import generate_pagination_where_clause +from synapse.storage.engines import PostgresEngine from synapse.storage.relations import ( AggregationPaginationToken, PaginationChunk, RelationPaginationToken, ) from synapse.types import JsonDict -from synapse.util.caches.descriptors import cached +from synapse.util.caches.descriptors import cached, cachedList if TYPE_CHECKING: from synapse.server import HomeServer @@ -340,20 +351,24 @@ class RelationsWorkerStore(SQLBaseStore): ) @cached() - async def get_applicable_edit( - self, event_id: str, room_id: str - ) -> Optional[EventBase]: + def get_applicable_edit(self, event_id: str) -> Optional[EventBase]: + raise NotImplementedError() + + @cachedList(cached_method_name="get_applicable_edit", list_name="event_ids") + async def _get_applicable_edits( + self, event_ids: Collection[str] + ) -> Dict[str, Optional[EventBase]]: """Get the most recent edit (if any) that has happened for the given - event. + events. Correctly handles checking whether edits were allowed to happen. Args: - event_id: The original event ID - room_id: The original event's room ID + event_ids: The original event IDs Returns: - The most recent edit, if any. + A map of the most recent edit for each event. If there are no edits, + the event will map to None. """ # We only allow edits for `m.room.message` events that have the same sender @@ -362,37 +377,67 @@ class RelationsWorkerStore(SQLBaseStore): # Fetches latest edit that has the same type and sender as the # original, and is an `m.room.message`. - sql = """ - SELECT edit.event_id FROM events AS edit - INNER JOIN event_relations USING (event_id) - INNER JOIN events AS original ON - original.event_id = relates_to_id - AND edit.type = original.type - AND edit.sender = original.sender - WHERE - relates_to_id = ? - AND relation_type = ? - AND edit.room_id = ? - AND edit.type = 'm.room.message' - ORDER by edit.origin_server_ts DESC, edit.event_id DESC - LIMIT 1 - """ + if isinstance(self.database_engine, PostgresEngine): + # The `DISTINCT ON` clause will pick the *first* row it encounters, + # so ordering by origin server ts + event ID desc will ensure we get + # the latest edit. + sql = """ + SELECT DISTINCT ON (original.event_id) original.event_id, edit.event_id FROM events AS edit + INNER JOIN event_relations USING (event_id) + INNER JOIN events AS original ON + original.event_id = relates_to_id + AND edit.type = original.type + AND edit.sender = original.sender + AND edit.room_id = original.room_id + WHERE + %s + AND relation_type = ? + AND edit.type = 'm.room.message' + ORDER by original.event_id DESC, edit.origin_server_ts DESC, edit.event_id DESC + """ + else: + # SQLite uses a simplified query which returns all edits for an + # original event. The results are then de-duplicated when turned into + # a dict. Due to the chosen ordering, the latest edit stomps on + # earlier edits. + sql = """ + SELECT original.event_id, edit.event_id FROM events AS edit + INNER JOIN event_relations USING (event_id) + INNER JOIN events AS original ON + original.event_id = relates_to_id + AND edit.type = original.type + AND edit.sender = original.sender + AND edit.room_id = original.room_id + WHERE + %s + AND relation_type = ? + AND edit.type = 'm.room.message' + ORDER by edit.origin_server_ts, edit.event_id + """ - def _get_applicable_edit_txn(txn: LoggingTransaction) -> Optional[str]: - txn.execute(sql, (event_id, RelationTypes.REPLACE, room_id)) - row = txn.fetchone() - if row: - return row[0] - return None + def _get_applicable_edits_txn(txn: LoggingTransaction) -> Dict[str, str]: + clause, args = make_in_list_sql_clause( + txn.database_engine, "relates_to_id", event_ids + ) + args.append(RelationTypes.REPLACE) - edit_id = await self.db_pool.runInteraction( - "get_applicable_edit", _get_applicable_edit_txn + txn.execute(sql % (clause,), args) + return dict(cast(Iterable[Tuple[str, str]], txn.fetchall())) + + edit_ids = await self.db_pool.runInteraction( + "get_applicable_edits", _get_applicable_edits_txn ) - if not edit_id: - return None + edits = await self.get_events(edit_ids.values()) # type: ignore[attr-defined] - return await self.get_event(edit_id, allow_none=True) # type: ignore[attr-defined] + # Map to the original event IDs to the edit events. + # + # There might not be an edit event due to there being no edits or + # due to the event not being known, either case is treated the same. + return { + original_event_id: edits.get(edit_ids.get(original_event_id)) + for original_event_id in event_ids + } @cached() async def get_thread_summary( @@ -612,9 +657,6 @@ class RelationsWorkerStore(SQLBaseStore): The bundled aggregations for an event, if bundled aggregations are enabled and the event can have bundled aggregations. """ - # State events and redacted events do not get bundled aggregations. - if event.is_state() or event.internal_metadata.is_redacted(): - return None # Do not bundle aggregations for an event which represents an edit or an # annotation. It does not make sense for them to have related events. @@ -642,13 +684,6 @@ class RelationsWorkerStore(SQLBaseStore): if references.chunk: aggregations.references = references.to_dict() - edit = None - if event.type == EventTypes.Message: - edit = await self.get_applicable_edit(event_id, room_id) - - if edit: - aggregations.replace = edit - # If this event is the start of a thread, include a summary of the replies. if self._msc3440_enabled: thread_count, latest_thread_event = await self.get_thread_summary( @@ -668,9 +703,7 @@ class RelationsWorkerStore(SQLBaseStore): return aggregations async def get_bundled_aggregations( - self, - events: Iterable[EventBase], - user_id: str, + self, events: Iterable[EventBase], user_id: str ) -> Dict[str, BundledAggregations]: """Generate bundled aggregations for events. @@ -683,13 +716,28 @@ class RelationsWorkerStore(SQLBaseStore): events may have bundled aggregations in the results. """ - # TODO Parallelize. - results = {} + # State events and redacted events do not get bundled aggregations. + events = [ + event + for event in events + if not event.is_state() and not event.internal_metadata.is_redacted() + ] + + # event ID -> bundled aggregation in non-serialized form. + results: Dict[str, BundledAggregations] = {} + + # Fetch other relations per event. for event in events: event_result = await self._get_bundled_aggregation_for_event(event, user_id) if event_result: results[event.event_id] = event_result + # Fetch any edits. + event_ids = [event.event_id for event in events] + edits = await self._get_applicable_edits(event_ids) + for event_id, edit in edits.items(): + results.setdefault(event_id, BundledAggregations()).replace = edit + return results -- cgit 1.4.1