123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466 |
- # Copyright 2021 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,
- Collection,
- Dict,
- FrozenSet,
- Iterable,
- List,
- Optional,
- Tuple,
- )
- import attr
- from synapse.api.constants import RelationTypes
- from synapse.api.errors import SynapseError
- from synapse.events import EventBase, relation_from_event
- from synapse.storage.databases.main.relations import _RelatedEvent
- from synapse.types import JsonDict, Requester, StreamToken, UserID
- from synapse.visibility import filter_events_for_client
- if TYPE_CHECKING:
- from synapse.server import HomeServer
- logger = logging.getLogger(__name__)
- @attr.s(slots=True, frozen=True, auto_attribs=True)
- class _ThreadAggregation:
- # The latest event in the thread.
- latest_event: EventBase
- # The total number of events in the thread.
- count: int
- # True if the current user has sent an event to the thread.
- current_user_participated: bool
- @attr.s(slots=True, auto_attribs=True)
- class BundledAggregations:
- """
- The bundled aggregations for an event.
- Some values require additional processing during serialization.
- """
- annotations: Optional[JsonDict] = None
- references: Optional[JsonDict] = None
- replace: Optional[EventBase] = None
- thread: Optional[_ThreadAggregation] = None
- def __bool__(self) -> bool:
- return bool(self.annotations or self.references or self.replace or self.thread)
- class RelationsHandler:
- def __init__(self, hs: "HomeServer"):
- self._main_store = hs.get_datastores().main
- self._storage = hs.get_storage()
- self._auth = hs.get_auth()
- self._clock = hs.get_clock()
- self._event_handler = hs.get_event_handler()
- self._event_serializer = hs.get_event_client_serializer()
- async def get_relations(
- self,
- requester: Requester,
- event_id: str,
- room_id: str,
- relation_type: Optional[str] = None,
- event_type: Optional[str] = None,
- aggregation_key: Optional[str] = None,
- limit: int = 5,
- direction: str = "b",
- from_token: Optional[StreamToken] = None,
- to_token: Optional[StreamToken] = None,
- ) -> JsonDict:
- """Get related events of a event, ordered by topological ordering.
- TODO Accept a PaginationConfig instead of individual pagination parameters.
- Args:
- requester: The user requesting the relations.
- event_id: Fetch events that relate to this event ID.
- room_id: The room the event belongs to.
- relation_type: Only fetch events with this relation type, if given.
- event_type: Only fetch events with this event type, if given.
- aggregation_key: Only fetch events with this aggregation key, if given.
- limit: Only fetch the most recent `limit` events.
- direction: Whether to fetch the most recent first (`"b"`) or the
- oldest first (`"f"`).
- from_token: Fetch rows from the given token, or from the start if None.
- to_token: Fetch rows up to the given token, or up to the end if None.
- Returns:
- The pagination chunk.
- """
- user_id = requester.user.to_string()
- # TODO Properly handle a user leaving a room.
- (_, member_event_id) = await self._auth.check_user_in_room_or_world_readable(
- room_id, user_id, allow_departed_users=True
- )
- # This gets the original event and checks that a) the event exists and
- # b) the user is allowed to view it.
- event = await self._event_handler.get_event(requester.user, room_id, event_id)
- if event is None:
- raise SynapseError(404, "Unknown parent event.")
- # Note that ignored users are not passed into get_relations_for_event
- # below. Ignored users are handled in filter_events_for_client (and by
- # not passing them in here we should get a better cache hit rate).
- related_events, next_token = await self._main_store.get_relations_for_event(
- event_id=event_id,
- event=event,
- room_id=room_id,
- relation_type=relation_type,
- event_type=event_type,
- aggregation_key=aggregation_key,
- limit=limit,
- direction=direction,
- from_token=from_token,
- to_token=to_token,
- )
- events = await self._main_store.get_events_as_list(
- [e.event_id for e in related_events]
- )
- events = await filter_events_for_client(
- self._storage, user_id, events, is_peeking=(member_event_id is None)
- )
- now = self._clock.time_msec()
- # Do not bundle aggregations when retrieving the original event because
- # we want the content before relations are applied to it.
- original_event = self._event_serializer.serialize_event(
- event, now, bundle_aggregations=None
- )
- # The relations returned for the requested event do include their
- # bundled aggregations.
- aggregations = await self.get_bundled_aggregations(
- events, requester.user.to_string()
- )
- serialized_events = self._event_serializer.serialize_events(
- events, now, bundle_aggregations=aggregations
- )
- return_value = {
- "chunk": serialized_events,
- "original_event": original_event,
- }
- if next_token:
- return_value["next_batch"] = await next_token.to_string(self._main_store)
- if from_token:
- return_value["prev_batch"] = await from_token.to_string(self._main_store)
- return return_value
- async def get_relations_for_event(
- self,
- event_id: str,
- event: EventBase,
- room_id: str,
- relation_type: str,
- ignored_users: FrozenSet[str] = frozenset(),
- ) -> Tuple[List[_RelatedEvent], Optional[StreamToken]]:
- """Get a list of events which relate to an event, ordered by topological ordering.
- Args:
- event_id: Fetch events that relate to this event ID.
- event: The matching EventBase to event_id.
- room_id: The room the event belongs to.
- relation_type: The type of relation.
- ignored_users: The users ignored by the requesting user.
- Returns:
- List of event IDs that match relations requested. The rows are of
- the form `{"event_id": "..."}`.
- """
- # Call the underlying storage method, which is cached.
- related_events, next_token = await self._main_store.get_relations_for_event(
- event_id, event, room_id, relation_type, direction="f"
- )
- # Filter out ignored users and convert to the expected format.
- related_events = [
- event for event in related_events if event.sender not in ignored_users
- ]
- return related_events, next_token
- async def get_annotations_for_event(
- self,
- event_id: str,
- room_id: str,
- limit: int = 5,
- ignored_users: FrozenSet[str] = frozenset(),
- ) -> List[JsonDict]:
- """Get a list of annotations on the event, grouped by event type and
- aggregation key, sorted by count.
- This is used e.g. to get the what and how many reactions have happend
- on an event.
- Args:
- event_id: Fetch events that relate to this event ID.
- room_id: The room the event belongs to.
- limit: Only fetch the `limit` groups.
- ignored_users: The users ignored by the requesting user.
- Returns:
- List of groups of annotations that match. Each row is a dict with
- `type`, `key` and `count` fields.
- """
- # Get the base results for all users.
- full_results = await self._main_store.get_aggregation_groups_for_event(
- event_id, room_id, limit
- )
- # Then subtract off the results for any ignored users.
- ignored_results = await self._main_store.get_aggregation_groups_for_users(
- event_id, room_id, limit, ignored_users
- )
- filtered_results = []
- for result in full_results:
- key = (result["type"], result["key"])
- if key in ignored_results:
- result = result.copy()
- result["count"] -= ignored_results[key]
- if result["count"] <= 0:
- continue
- filtered_results.append(result)
- return filtered_results
- async def get_threads_for_events(
- self, event_ids: Collection[str], user_id: str, ignored_users: FrozenSet[str]
- ) -> Dict[str, _ThreadAggregation]:
- """Get the bundled aggregations for threads for the requested events.
- Args:
- event_ids: Events to get aggregations for threads.
- user_id: The user requesting the bundled aggregations.
- ignored_users: The users ignored by the requesting user.
- Returns:
- A dictionary mapping event ID to the thread information.
- May not contain a value for all requested event IDs.
- """
- user = UserID.from_string(user_id)
- # Fetch thread summaries.
- summaries = await self._main_store.get_thread_summaries(event_ids)
- # Only fetch participated for a limited selection based on what had
- # summaries.
- thread_event_ids = [
- event_id for event_id, summary in summaries.items() if summary
- ]
- participated = await self._main_store.get_threads_participated(
- thread_event_ids, user_id
- )
- # Then subtract off the results for any ignored users.
- ignored_results = await self._main_store.get_threaded_messages_per_user(
- thread_event_ids, ignored_users
- )
- # A map of event ID to the thread aggregation.
- results = {}
- for event_id, summary in summaries.items():
- if summary:
- thread_count, latest_thread_event = summary
- # Subtract off the count of any ignored users.
- for ignored_user in ignored_users:
- thread_count -= ignored_results.get((event_id, ignored_user), 0)
- # This is gnarly, but if the latest event is from an ignored user,
- # attempt to find one that isn't from an ignored user.
- if latest_thread_event.sender in ignored_users:
- room_id = latest_thread_event.room_id
- # If the root event is not found, something went wrong, do
- # not include a summary of the thread.
- event = await self._event_handler.get_event(user, room_id, event_id)
- if event is None:
- continue
- potential_events, _ = await self.get_relations_for_event(
- event_id,
- event,
- room_id,
- RelationTypes.THREAD,
- ignored_users,
- )
- # If all found events are from ignored users, do not include
- # a summary of the thread.
- if not potential_events:
- continue
- # The *last* event returned is the one that is cared about.
- event = await self._event_handler.get_event(
- user, room_id, potential_events[-1].event_id
- )
- # It is unexpected that the event will not exist.
- if event is None:
- logger.warning(
- "Unable to fetch latest event in a thread with event ID: %s",
- potential_events[-1].event_id,
- )
- continue
- latest_thread_event = event
- results[event_id] = _ThreadAggregation(
- latest_event=latest_thread_event,
- count=thread_count,
- # If there's a thread summary it must also exist in the
- # participated dictionary.
- current_user_participated=participated[event_id],
- )
- return results
- async def get_bundled_aggregations(
- self, events: Iterable[EventBase], user_id: str
- ) -> Dict[str, BundledAggregations]:
- """Generate bundled aggregations for events.
- Args:
- events: The iterable of events to calculate bundled aggregations for.
- user_id: The user requesting the bundled aggregations.
- Returns:
- A map of event ID to the bundled aggregations for the event.
- Not all requested events may exist in the results (if they don't have
- bundled aggregations).
- The results may include additional events which are related to the
- requested events.
- """
- # De-duplicated events by ID to handle the same event requested multiple times.
- events_by_id = {}
- # A map of event ID to the relation in that event, if there is one.
- relations_by_id: Dict[str, str] = {}
- for event in events:
- # State events do not get bundled aggregations.
- if event.is_state():
- continue
- relates_to = relation_from_event(event)
- if relates_to:
- # An event which is a replacement (ie edit) or annotation (ie,
- # reaction) may not have any other event related to it.
- if relates_to.rel_type in (
- RelationTypes.ANNOTATION,
- RelationTypes.REPLACE,
- ):
- continue
- # Track the event's relation information for later.
- relations_by_id[event.event_id] = relates_to.rel_type
- # The event should get bundled aggregations.
- events_by_id[event.event_id] = event
- # event ID -> bundled aggregation in non-serialized form.
- results: Dict[str, BundledAggregations] = {}
- # Fetch any ignored users of the requesting user.
- ignored_users = await self._main_store.ignored_users(user_id)
- # Threads are special as the latest event of a thread might cause additional
- # events to be fetched. Thus, we check those first!
- # Fetch thread summaries (but only for the directly requested events).
- threads = await self.get_threads_for_events(
- # It is not valid to start a thread on an event which itself relates to another event.
- [eid for eid in events_by_id.keys() if eid not in relations_by_id],
- user_id,
- ignored_users,
- )
- for event_id, thread in threads.items():
- results.setdefault(event_id, BundledAggregations()).thread = thread
- # If the latest event in a thread is not already being fetched,
- # add it. This ensures that the bundled aggregations for the
- # latest thread event is correct.
- latest_thread_event = thread.latest_event
- if latest_thread_event and latest_thread_event.event_id not in events_by_id:
- events_by_id[latest_thread_event.event_id] = latest_thread_event
- # Keep relations_by_id in sync with events_by_id:
- #
- # We know that the latest event in a thread has a thread relation
- # (as that is what makes it part of the thread).
- relations_by_id[latest_thread_event.event_id] = RelationTypes.THREAD
- # Fetch other relations per event.
- for event in events_by_id.values():
- # Fetch any annotations (ie, reactions) to bundle with this event.
- annotations = await self.get_annotations_for_event(
- event.event_id, event.room_id, ignored_users=ignored_users
- )
- if annotations:
- results.setdefault(
- event.event_id, BundledAggregations()
- ).annotations = {"chunk": annotations}
- # Fetch any references to bundle with this event.
- references, next_token = await self.get_relations_for_event(
- event.event_id,
- event,
- event.room_id,
- RelationTypes.REFERENCE,
- ignored_users=ignored_users,
- )
- if references:
- aggregations = results.setdefault(event.event_id, BundledAggregations())
- aggregations.references = {
- "chunk": [{"event_id": ev.event_id} for ev in references]
- }
- if next_token:
- aggregations.references["next_batch"] = await next_token.to_string(
- self._main_store
- )
- # Fetch any edits (but not for redacted events).
- #
- # Note that there is no use in limiting edits by ignored users since the
- # parent event should be ignored in the first place if the user is ignored.
- edits = await self._main_store.get_applicable_edits(
- [
- event_id
- for event_id, event in events_by_id.items()
- if not event.internal_metadata.is_redacted()
- ]
- )
- for event_id, edit in edits.items():
- results.setdefault(event_id, BundledAggregations()).replace = edit
- return results
|