Batch fetch bundled annotations (#14491)

Avoid an n+1 query problem and fetch the bundled aggregations for
m.annotation relations in a single query instead of a query per event.

This applies similar logic for as was previously done for edits in
8b309adb43 (#11660) and threads
in b65acead42 (#11752).
This commit is contained in:
Patrick Cloke 2022-11-22 07:26:11 -05:00 committed by GitHub
parent da933bfc3f
commit 1799a54a54
No known key found for this signature in database
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5 changed files with 203 additions and 142 deletions

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@ -0,0 +1 @@
Reduce database load of [Client-Server endpoints](https://spec.matrix.org/v1.4/client-server-api/#aggregations) which return bundled aggregations.

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@ -13,7 +13,16 @@
# limitations under the License.
import enum
import logging
from typing import TYPE_CHECKING, Dict, FrozenSet, Iterable, List, Optional, Tuple
from typing import (
TYPE_CHECKING,
Collection,
Dict,
FrozenSet,
Iterable,
List,
Optional,
Tuple,
)
import attr
@ -259,48 +268,64 @@ class RelationsHandler:
e.msg,
)
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
async def get_annotations_for_events(
self, event_ids: Collection[str], ignored_users: FrozenSet[str] = frozenset()
) -> Dict[str, List[JsonDict]]:
"""Get a list of annotations to the given events, 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
This is used e.g. to get the what and how many reactions have happened
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.
event_ids: Fetch events that relate to these event IDs.
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.
A map of event IDs to a list of groups of annotations that match.
Each entry 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
full_results = await self._main_store.get_aggregation_groups_for_events(
event_ids
)
# Avoid additional logic if there are no ignored users.
if not ignored_users:
return {
event_id: results
for event_id, results in full_results.items()
if results
}
# 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
[event_id for event_id, results in full_results.items() if results],
ignored_users,
)
filtered_results = []
for result in full_results:
filtered_results = {}
for event_id, results in full_results.items():
# If no annotations, skip.
if not results:
continue
# If there are not ignored results for this event, copy verbatim.
if event_id not in ignored_results:
filtered_results[event_id] = results
continue
# Otherwise, subtract out the ignored results.
event_ignored_results = ignored_results[event_id]
for result in results:
key = (result["type"], result["key"])
if key in ignored_results:
if key in event_ignored_results:
# Ensure to not modify the cache.
result = result.copy()
result["count"] -= ignored_results[key]
result["count"] -= event_ignored_results[key]
if result["count"] <= 0:
continue
filtered_results.append(result)
filtered_results.setdefault(event_id, []).append(result)
return filtered_results
@ -366,7 +391,10 @@ class RelationsHandler:
results = {}
for event_id, summary in summaries.items():
if summary:
# If no thread, skip.
if not summary:
continue
thread_count, latest_thread_event = summary
# Subtract off the count of any ignored users.
@ -496,17 +524,18 @@ class RelationsHandler:
# (as that is what makes it part of the thread).
relations_by_id[latest_thread_event.event_id] = RelationTypes.THREAD
# Fetch any annotations (ie, reactions) to bundle with this event.
annotations_by_event_id = await self.get_annotations_for_events(
events_by_id.keys(), ignored_users=ignored_users
)
for event_id, annotations in annotations_by_event_id.items():
if annotations:
results.setdefault(event_id, BundledAggregations()).annotations = {
"chunk": annotations
}
# 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,

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@ -20,6 +20,7 @@ from typing import (
FrozenSet,
Iterable,
List,
Mapping,
Optional,
Set,
Tuple,
@ -394,106 +395,136 @@ class RelationsWorkerStore(SQLBaseStore):
)
return result is not None
@cached(tree=True)
async def get_aggregation_groups_for_event(
self, event_id: str, room_id: str, limit: int = 5
) -> List[JsonDict]:
"""Get a list of annotations on the event, grouped by event type and
@cached()
async def get_aggregation_groups_for_event(self, event_id: str) -> List[JsonDict]:
raise NotImplementedError()
@cachedList(
cached_method_name="get_aggregation_groups_for_event", list_name="event_ids"
)
async def get_aggregation_groups_for_events(
self, event_ids: Collection[str]
) -> Mapping[str, Optional[List[JsonDict]]]:
"""Get a list of annotations on the given events, 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.
event_ids: Fetch events that relate to these event IDs.
Returns:
List of groups of annotations that match. Each row is a dict with
`type`, `key` and `count` fields.
A map of event IDs to a list of groups of annotations that match.
Each entry is a dict with `type`, `key` and `count` fields.
"""
# The number of entries to return per event ID.
limit = 5
clause, args = make_in_list_sql_clause(
self.database_engine, "relates_to_id", event_ids
)
args.append(RelationTypes.ANNOTATION)
sql = f"""
SELECT
relates_to_id,
annotation.type,
aggregation_key,
COUNT(DISTINCT annotation.sender)
FROM events AS annotation
INNER JOIN event_relations USING (event_id)
INNER JOIN events AS parent ON
parent.event_id = relates_to_id
AND parent.room_id = annotation.room_id
WHERE
{clause}
AND relation_type = ?
GROUP BY relates_to_id, annotation.type, aggregation_key
ORDER BY relates_to_id, COUNT(*) DESC
"""
args = [
event_id,
room_id,
RelationTypes.ANNOTATION,
limit,
]
sql = """
SELECT type, aggregation_key, COUNT(DISTINCT sender)
FROM event_relations
INNER JOIN events USING (event_id)
WHERE relates_to_id = ? AND room_id = ? AND relation_type = ?
GROUP BY relation_type, type, aggregation_key
ORDER BY COUNT(*) DESC
LIMIT ?
"""
def _get_aggregation_groups_for_event_txn(
def _get_aggregation_groups_for_events_txn(
txn: LoggingTransaction,
) -> List[JsonDict]:
) -> Mapping[str, List[JsonDict]]:
txn.execute(sql, args)
return [{"type": row[0], "key": row[1], "count": row[2]} for row in txn]
result: Dict[str, List[JsonDict]] = {}
for event_id, type, key, count in cast(
List[Tuple[str, str, str, int]], txn
):
event_results = result.setdefault(event_id, [])
# Limit the number of results per event ID.
if len(event_results) == limit:
continue
event_results.append({"type": type, "key": key, "count": count})
return result
return await self.db_pool.runInteraction(
"get_aggregation_groups_for_event", _get_aggregation_groups_for_event_txn
"get_aggregation_groups_for_events", _get_aggregation_groups_for_events_txn
)
async def get_aggregation_groups_for_users(
self,
event_id: str,
room_id: str,
limit: int,
users: FrozenSet[str] = frozenset(),
) -> Dict[Tuple[str, str], int]:
self, event_ids: Collection[str], users: FrozenSet[str]
) -> Dict[str, Dict[Tuple[str, str], int]]:
"""Fetch the partial aggregations for an event for specific users.
This is used, in conjunction with get_aggregation_groups_for_event, to
remove information from the results for ignored users.
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.
event_ids: Fetch events that relate to these event IDs.
users: The users to fetch information for.
Returns:
A map of (event type, aggregation key) to a count of users.
A map of event ID to a map of (event type, aggregation key) to a
count of users.
"""
if not users:
return {}
args: List[Union[str, int]] = [
event_id,
room_id,
RelationTypes.ANNOTATION,
]
events_sql, args = make_in_list_sql_clause(
self.database_engine, "relates_to_id", event_ids
)
users_sql, users_args = make_in_list_sql_clause(
self.database_engine, "sender", users
self.database_engine, "annotation.sender", users
)
args.extend(users_args)
args.append(RelationTypes.ANNOTATION)
sql = f"""
SELECT type, aggregation_key, COUNT(DISTINCT sender)
FROM event_relations
INNER JOIN events USING (event_id)
WHERE relates_to_id = ? AND room_id = ? AND relation_type = ? AND {users_sql}
GROUP BY relation_type, type, aggregation_key
ORDER BY COUNT(*) DESC
LIMIT ?
SELECT
relates_to_id,
annotation.type,
aggregation_key,
COUNT(DISTINCT annotation.sender)
FROM events AS annotation
INNER JOIN event_relations USING (event_id)
INNER JOIN events AS parent ON
parent.event_id = relates_to_id
AND parent.room_id = annotation.room_id
WHERE {events_sql} AND {users_sql} AND relation_type = ?
GROUP BY relates_to_id, annotation.type, aggregation_key
ORDER BY relates_to_id, COUNT(*) DESC
"""
def _get_aggregation_groups_for_users_txn(
txn: LoggingTransaction,
) -> Dict[Tuple[str, str], int]:
txn.execute(sql, args + [limit])
) -> Dict[str, Dict[Tuple[str, str], int]]:
txn.execute(sql, args)
return {(row[0], row[1]): row[2] for row in txn}
result: Dict[str, Dict[Tuple[str, str], int]] = {}
for event_id, type, key, count in cast(
List[Tuple[str, str, str, int]], txn
):
result.setdefault(event_id, {})[(type, key)] = count
return result
return await self.db_pool.runInteraction(
"get_aggregation_groups_for_users", _get_aggregation_groups_for_users_txn

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@ -503,7 +503,7 @@ def cachedList(
is specified as a list that is iterated through to lookup keys in the
original cache. A new tuple consisting of the (deduplicated) keys that weren't in
the cache gets passed to the original function, which is expected to results
in a map of key to value for each passed value. THe new results are stored in the
in a map of key to value for each passed value. The new results are stored in the
original cache. Note that any missing values are cached as None.
Args:

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@ -1108,7 +1108,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
# The "user" sent the root event and is making queries for the bundled
# aggregations: they have participated.
self._test_bundled_aggregations(RelationTypes.THREAD, _gen_assert(True), 9)
self._test_bundled_aggregations(RelationTypes.THREAD, _gen_assert(True), 8)
# The "user2" sent replies in the thread and is making queries for the
# bundled aggregations: they have participated.
#
@ -1170,7 +1170,7 @@ class BundledAggregationsTestCase(BaseRelationsTestCase):
bundled_aggregations["latest_event"].get("unsigned"),
)
self._test_bundled_aggregations(RelationTypes.THREAD, assert_thread, 9)
self._test_bundled_aggregations(RelationTypes.THREAD, assert_thread, 8)
def test_nested_thread(self) -> None:
"""