Bundle aggregations outside of the serialization method

changelog.d/11612.misc

@@ -0,0 +1 @@
+Avoid database access in the JSON serialization process.

synapse/events/utils.py

@@ -14,32 +14,18 @@
 # limitations under the License.
 import collections.abc
 import re
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Callable,
-    Dict,
-    Iterable,
-    List,
-    Mapping,
-    Optional,
-    Union,
-)
+from typing import Any, Callable, Dict, Iterable, List, Mapping, Optional, Union
 
 from frozendict import frozendict
 
 from synapse.api.constants import EventContentFields, EventTypes, RelationTypes
 from synapse.api.errors import Codes, SynapseError
 from synapse.api.room_versions import RoomVersion
 from synapse.types import JsonDict
-from synapse.util.async_helpers import yieldable_gather_results
 from synapse.util.frozenutils import unfreeze
 
 from . import EventBase
 
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
 # Split strings on "." but not "\." This uses a negative lookbehind assertion for '\'
 # (?<!stuff) matches if the current position in the string is not preceded
 # by a match for 'stuff'.
@@ -385,17 +371,12 @@ class EventClientSerializer:
     clients.
     """
 
-    def __init__(self, hs: "HomeServer"):
-        self.store = hs.get_datastore()
-        self._msc1849_enabled = hs.config.experimental.msc1849_enabled
-        self._msc3440_enabled = hs.config.experimental.msc3440_enabled
-
-    async def serialize_event(
+    def serialize_event(
         self,
         event: Union[JsonDict, EventBase],
         time_now: int,
         *,
-        bundle_aggregations: bool = False,
+        bundle_aggregations: Optional[Dict[str, JsonDict]] = None,
         **kwargs: Any,
     ) -> JsonDict:
         """Serializes a single event.
@@ -418,66 +399,41 @@ async def serialize_event(
         serialized_event = serialize_event(event, time_now, **kwargs)
 
         # Check if there are any bundled aggregations to include with the event.
-        #
-        # Do not bundle aggregations if any of the following at true:
-        #
-        # * Support is disabled via the configuration or the caller.
-        # * The event is a state event.
-        # * The event has been redacted.
-        if (
-            self._msc1849_enabled
-            and bundle_aggregations
-            and not event.is_state()
-            and not event.internal_metadata.is_redacted()
-        ):
-            await self._injected_bundled_aggregations(event, time_now, serialized_event)
+        if bundle_aggregations:
+            event_aggregations = bundle_aggregations.get(event.event_id)
+            if event_aggregations:
+                self._injected_bundled_aggregations(
+                    event,
+                    time_now,
+                    bundle_aggregations[event.event_id],
+                    serialized_event,
+                )
 
         return serialized_event
 
-    async def _injected_bundled_aggregations(
-        self, event: EventBase, time_now: int, serialized_event: JsonDict
+    def _injected_bundled_aggregations(
+        self,
+        event: EventBase,
+        time_now: int,
+        aggregations: JsonDict,
+        serialized_event: JsonDict,
     ) -> None:
         """Potentially injects bundled aggregations into the unsigned portion of the serialized event.
 
         Args:
             event: The event being serialized.
             time_now: The current time in milliseconds
+            aggregations: The bundled aggregation to serialize.
             serialized_event: The serialized event which may be modified.
 
         """
-        # 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.
-        relates_to = event.content.get("m.relates_to")
-        if isinstance(relates_to, (dict, frozendict)):
-            relation_type = relates_to.get("rel_type")
-            if relation_type in (RelationTypes.ANNOTATION, RelationTypes.REPLACE):
-                return
-
-        event_id = event.event_id
-        room_id = event.room_id
-
-        # The bundled aggregations to include.
-        aggregations = {}
-
-        annotations = await self.store.get_aggregation_groups_for_event(
-            event_id, room_id
-        )
-        if annotations.chunk:
-            aggregations[RelationTypes.ANNOTATION] = annotations.to_dict()
+        # Make a copy in-case the object is cached.
+        aggregations = aggregations.copy()
 
-        references = await self.store.get_relations_for_event(
-            event_id, room_id, RelationTypes.REFERENCE, direction="f"
-        )
-        if references.chunk:
-            aggregations[RelationTypes.REFERENCE] = references.to_dict()
-
-        edit = None
-        if event.type == EventTypes.Message:
-            edit = await self.store.get_applicable_edit(event_id, room_id)
-
-        if edit:
+        if RelationTypes.REPLACE in aggregations:
             # If there is an edit replace the content, preserving existing
             # relations.
+            edit = aggregations[RelationTypes.REPLACE]
 
             # Ensure we take copies of the edit content, otherwise we risk modifying
             # the original event.
@@ -502,27 +458,19 @@ async def _injected_bundled_aggregations(
             }
 
         # 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.store.get_thread_summary(event_id, room_id)
-            if latest_thread_event:
-                aggregations[RelationTypes.THREAD] = {
-                    # Don't bundle aggregations as this could recurse forever.
-                    "latest_event": await self.serialize_event(
-                        latest_thread_event, time_now, bundle_aggregations=False
-                    ),
-                    "count": thread_count,
-                }
-
-        # If any bundled aggregations were found, include them.
-        if aggregations:
-            serialized_event["unsigned"].setdefault("m.relations", {}).update(
-                aggregations
+        if RelationTypes.THREAD in aggregations:
+            # Serialize the latest thread event.
+            latest_thread_event = aggregations[RelationTypes.THREAD]["latest_event"]
+
+            # Don't bundle aggregations as this could recurse forever.
+            aggregations[RelationTypes.THREAD]["latest_event"] = self.serialize_event(
+                latest_thread_event, time_now, bundle_aggregations=None
             )
 
-    async def serialize_events(
+        # Include the bundled aggregations in the event.
+        serialized_event["unsigned"].setdefault("m.relations", {}).update(aggregations)
+
+    def serialize_events(
         self, events: Iterable[Union[JsonDict, EventBase]], time_now: int, **kwargs: Any
     ) -> List[JsonDict]:
         """Serializes multiple events.
@@ -535,9 +483,9 @@ async def serialize_events(
         Returns:
             The list of serialized events
         """
-        return await yieldable_gather_results(
-            self.serialize_event, events, time_now=time_now, **kwargs
-        )
+        return [
+            self.serialize_event(event, time_now=time_now, **kwargs) for event in events
+        ]
 
 
 def copy_power_levels_contents(

synapse/handlers/events.py

@@ -119,7 +119,7 @@ async def get_stream(
 
             events.extend(to_add)
 
-            chunks = await self._event_serializer.serialize_events(
+            chunks = self._event_serializer.serialize_events(
                 events,
                 time_now,
                 as_client_event=as_client_event,

synapse/handlers/initial_sync.py

@@ -170,7 +170,7 @@ async def handle_room(event: RoomsForUser) -> None:
                 d["inviter"] = event.sender
 
                 invite_event = await self.store.get_event(event.event_id)
-                d["invite"] = await self._event_serializer.serialize_event(
+                d["invite"] = self._event_serializer.serialize_event(
                     invite_event,
                     time_now,
                     as_client_event=as_client_event,
@@ -222,7 +222,7 @@ async def handle_room(event: RoomsForUser) -> None:
 
                 d["messages"] = {
                     "chunk": (
-                        await self._event_serializer.serialize_events(
+                        self._event_serializer.serialize_events(
                             messages,
                             time_now=time_now,
                             as_client_event=as_client_event,
@@ -232,7 +232,7 @@ async def handle_room(event: RoomsForUser) -> None:
                     "end": await end_token.to_string(self.store),
                 }
 
-                d["state"] = await self._event_serializer.serialize_events(
+                d["state"] = self._event_serializer.serialize_events(
                     current_state.values(),
                     time_now=time_now,
                     as_client_event=as_client_event,
@@ -376,16 +376,14 @@ async def _room_initial_sync_parted(
             "messages": {
                 "chunk": (
                     # Don't bundle aggregations as this is a deprecated API.
-                    await self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(messages, time_now)
                 ),
                 "start": await start_token.to_string(self.store),
                 "end": await end_token.to_string(self.store),
             },
             "state": (
                 # Don't bundle aggregations as this is a deprecated API.
-                await self._event_serializer.serialize_events(
-                    room_state.values(), time_now
-                )
+                self._event_serializer.serialize_events(room_state.values(), time_now)
             ),
             "presence": [],
             "receipts": [],
@@ -404,7 +402,7 @@ async def _room_initial_sync_joined(
         # TODO: These concurrently
         time_now = self.clock.time_msec()
         # Don't bundle aggregations as this is a deprecated API.
-        state = await self._event_serializer.serialize_events(
+        state = self._event_serializer.serialize_events(
             current_state.values(), time_now
         )
 
@@ -480,7 +478,7 @@ async def get_receipts() -> List[JsonDict]:
             "messages": {
                 "chunk": (
                     # Don't bundle aggregations as this is a deprecated API.
-                    await self._event_serializer.serialize_events(messages, time_now)
+                    self._event_serializer.serialize_events(messages, time_now)
                 ),
                 "start": await start_token.to_string(self.store),
                 "end": await end_token.to_string(self.store),

synapse/handlers/message.py

@@ -246,7 +246,7 @@ async def get_state_events(
                 room_state = room_state_events[membership_event_id]
 
         now = self.clock.time_msec()
-        events = await self._event_serializer.serialize_events(room_state.values(), now)
+        events = self._event_serializer.serialize_events(room_state.values(), now)
         return events
 
     async def get_joined_members(self, requester: Requester, room_id: str) -> dict:

synapse/handlers/pagination.py

@@ -537,14 +537,16 @@ async def get_messages(
                 state_dict = await self.store.get_events(list(state_ids.values()))
                 state = state_dict.values()
 
+        aggregations = await self.store.get_bundled_aggregations(events)
+
         time_now = self.clock.time_msec()
 
         chunk = {
             "chunk": (
-                await self._event_serializer.serialize_events(
+                self._event_serializer.serialize_events(
                     events,
                     time_now,
-                    bundle_aggregations=True,
+                    bundle_aggregations=aggregations,
                     as_client_event=as_client_event,
                 )
             ),
@@ -553,7 +555,7 @@ async def get_messages(
         }
 
         if state:
-            chunk["state"] = await self._event_serializer.serialize_events(
+            chunk["state"] = self._event_serializer.serialize_events(
                 state, time_now, as_client_event=as_client_event
             )
 

synapse/handlers/room.py

@@ -1177,6 +1177,16 @@ async def filter_evts(events: List[EventBase]) -> List[EventBase]:
         # `filtered` rather than the event we retrieved from the datastore.
         results["event"] = filtered[0]
 
+        # Fetch the aggregations.
+        aggregations = await self.store.get_bundled_aggregations([results["event"]])
+        aggregations.update(
+            await self.store.get_bundled_aggregations(results["events_before"])
+        )
+        aggregations.update(
+            await self.store.get_bundled_aggregations(results["events_after"])
+        )
+        results["aggregations"] = aggregations
+
         if results["events_after"]:
             last_event_id = results["events_after"][-1].event_id
         else:

synapse/handlers/search.py

@@ -420,10 +420,10 @@ async def search(
         time_now = self.clock.time_msec()
 
         for context in contexts.values():
-            context["events_before"] = await self._event_serializer.serialize_events(
+            context["events_before"] = self._event_serializer.serialize_events(
                 context["events_before"], time_now
             )
-            context["events_after"] = await self._event_serializer.serialize_events(
+            context["events_after"] = self._event_serializer.serialize_events(
                 context["events_after"], time_now
             )
 
@@ -441,9 +441,7 @@ async def search(
             results.append(
                 {
                     "rank": rank_map[e.event_id],
-                    "result": (
-                        await self._event_serializer.serialize_event(e, time_now)
-                    ),
+                    "result": self._event_serializer.serialize_event(e, time_now),
                     "context": contexts.get(e.event_id, {}),
                 }
             )
@@ -457,7 +455,7 @@ async def search(
         if state_results:
             s = {}
             for room_id, state_events in state_results.items():
-                s[room_id] = await self._event_serializer.serialize_events(
+                s[room_id] = self._event_serializer.serialize_events(
                     state_events, time_now
                 )
 

synapse/rest/admin/rooms.py

@@ -424,7 +424,7 @@ async def on_GET(
         event_ids = await self.store.get_current_state_ids(room_id)
         events = await self.store.get_events(event_ids.values())
         now = self.clock.time_msec()
-        room_state = await self._event_serializer.serialize_events(events.values(), now)
+        room_state = self._event_serializer.serialize_events(events.values(), now)
         ret = {"state": room_state}
 
         return HTTPStatus.OK, ret
@@ -744,22 +744,22 @@ async def on_GET(
             )
 
         time_now = self.clock.time_msec()
-        results["events_before"] = await self._event_serializer.serialize_events(
+        results["events_before"] = self._event_serializer.serialize_events(
             results["events_before"],
             time_now,
-            bundle_aggregations=True,
+            bundle_aggregations=results["aggregations"],
         )
-        results["event"] = await self._event_serializer.serialize_event(
+        results["event"] = self._event_serializer.serialize_event(
             results["event"],
             time_now,
-            bundle_aggregations=True,
+            bundle_aggregations=results["aggregations"],
         )
-        results["events_after"] = await self._event_serializer.serialize_events(
+        results["events_after"] = self._event_serializer.serialize_events(
             results["events_after"],
             time_now,
-            bundle_aggregations=True,
+            bundle_aggregations=results["aggregations"],
         )
-        results["state"] = await self._event_serializer.serialize_events(
+        results["state"] = self._event_serializer.serialize_events(
             results["state"], time_now
         )