Avoid unnecessary copies when filtering private read receipts. (#12711)

A minor optimization to avoid unnecessary copying/building
identical dictionaries when filtering private read receipts.

Also clarifies comments and cleans-up some tests.
This commit is contained in:
Šimon Brandner 2022-05-16 17:06:23 +02:00 committed by GitHub
parent b4eb163434
commit 3ce15cc7be
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4 changed files with 89 additions and 70 deletions

1
changelog.d/12711.misc Normal file
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@ -0,0 +1 @@
Optimize private read receipt filtering.

View file

@ -143,7 +143,7 @@ class InitialSyncHandler:
to_key=int(now_token.receipt_key),
)
if self.hs.config.experimental.msc2285_enabled:
receipt = ReceiptEventSource.filter_out_private(receipt, user_id)
receipt = ReceiptEventSource.filter_out_private_receipts(receipt, user_id)
tags_by_room = await self.store.get_tags_for_user(user_id)
@ -449,7 +449,9 @@ class InitialSyncHandler:
if not receipts:
return []
if self.hs.config.experimental.msc2285_enabled:
receipts = ReceiptEventSource.filter_out_private(receipts, user_id)
receipts = ReceiptEventSource.filter_out_private_receipts(
receipts, user_id
)
return receipts
presence, receipts, (messages, token) = await make_deferred_yieldable(

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@ -165,43 +165,69 @@ class ReceiptEventSource(EventSource[int, JsonDict]):
self.config = hs.config
@staticmethod
def filter_out_private(events: List[JsonDict], user_id: str) -> List[JsonDict]:
def filter_out_private_receipts(
rooms: List[JsonDict], user_id: str
) -> List[JsonDict]:
"""
This method takes in what is returned by
get_linearized_receipts_for_rooms() and goes through read receipts
filtering out m.read.private receipts if they were not sent by the
current user.
Filters a list of serialized receipts (as returned by /sync and /initialSync)
and removes private read receipts of other users.
This operates on the return value of get_linearized_receipts_for_rooms(),
which is wrapped in a cache. Care must be taken to ensure that the input
values are not modified.
Args:
rooms: A list of mappings, each mapping has a `content` field, which
is a map of event ID -> receipt type -> user ID -> receipt information.
Returns:
The same as rooms, but filtered.
"""
visible_events = []
result = []
# filter out private receipts the user shouldn't see
for event in events:
content = event.get("content", {})
new_event = event.copy()
new_event["content"] = {}
# Iterate through each room's receipt content.
for room in rooms:
# The receipt content with other user's private read receipts removed.
content = {}
for event_id, event_content in content.items():
receipt_event = {}
for receipt_type, receipt_content in event_content.items():
if receipt_type == ReceiptTypes.READ_PRIVATE:
user_rr = receipt_content.get(user_id, None)
if user_rr:
receipt_event[ReceiptTypes.READ_PRIVATE] = {
user_id: user_rr.copy()
# Iterate over each event ID / receipts for that event.
for event_id, orig_event_content in room.get("content", {}).items():
event_content = orig_event_content
# If there are private read receipts, additional logic is necessary.
if ReceiptTypes.READ_PRIVATE in event_content:
# Make a copy without private read receipts to avoid leaking
# other user's private read receipts..
event_content = {
receipt_type: receipt_value
for receipt_type, receipt_value in event_content.items()
if receipt_type != ReceiptTypes.READ_PRIVATE
}
else:
receipt_event[receipt_type] = receipt_content.copy()
# Only include the receipt event if it is non-empty.
if receipt_event:
new_event["content"][event_id] = receipt_event
# Copy the current user's private read receipt from the
# original content, if it exists.
user_private_read_receipt = orig_event_content[
ReceiptTypes.READ_PRIVATE
].get(user_id, None)
if user_private_read_receipt:
event_content[ReceiptTypes.READ_PRIVATE] = {
user_id: user_private_read_receipt
}
# Append new_event to visible_events unless empty
if len(new_event["content"].keys()) > 0:
visible_events.append(new_event)
# Include the event if there is at least one non-private read
# receipt or the current user has a private read receipt.
if event_content:
content[event_id] = event_content
return visible_events
# Include the event if there is at least one non-private read receipt
# or the current user has a private read receipt.
if content:
# Build a new event to avoid mutating the cache.
new_room = {k: v for k, v in room.items() if k != "content"}
new_room["content"] = content
result.append(new_room)
return result
async def get_new_events(
self,
@ -223,7 +249,9 @@ class ReceiptEventSource(EventSource[int, JsonDict]):
)
if self.config.experimental.msc2285_enabled:
events = ReceiptEventSource.filter_out_private(events, user.to_string())
events = ReceiptEventSource.filter_out_private_receipts(
events, user.to_string()
)
return events, to_key

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@ -12,7 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
from copy import deepcopy
from typing import List
from synapse.api.constants import ReceiptTypes
@ -125,42 +125,6 @@ class ReceiptsTestCase(unittest.HomeserverTestCase):
],
)
def test_handles_missing_content_of_m_read(self):
self._test_filters_private(
[
{
"content": {
"$14356419ggffg114394fHBLK:matrix.org": {ReceiptTypes.READ: {}},
"$1435641916114394fHBLK:matrix.org": {
ReceiptTypes.READ: {
"@user:jki.re": {
"ts": 1436451550453,
}
}
},
},
"room_id": "!jEsUZKDJdhlrceRyVU:example.org",
"type": "m.receipt",
}
],
[
{
"content": {
"$14356419ggffg114394fHBLK:matrix.org": {ReceiptTypes.READ: {}},
"$1435641916114394fHBLK:matrix.org": {
ReceiptTypes.READ: {
"@user:jki.re": {
"ts": 1436451550453,
}
}
},
},
"room_id": "!jEsUZKDJdhlrceRyVU:example.org",
"type": "m.receipt",
}
],
)
def test_handles_empty_event(self):
self._test_filters_private(
[
@ -332,9 +296,33 @@ class ReceiptsTestCase(unittest.HomeserverTestCase):
],
)
def test_we_do_not_mutate(self):
"""Ensure the input values are not modified."""
events = [
{
"content": {
"$1435641916114394fHBLK:matrix.org": {
ReceiptTypes.READ_PRIVATE: {
"@rikj:jki.re": {
"ts": 1436451550453,
}
}
}
},
"room_id": "!jEsUZKDJdhlrceRyVU:example.org",
"type": "m.receipt",
}
]
original_events = deepcopy(events)
self._test_filters_private(events, [])
# Since the events are fed in from a cache they should not be modified.
self.assertEqual(events, original_events)
def _test_filters_private(
self, events: List[JsonDict], expected_output: List[JsonDict]
):
"""Tests that the _filter_out_private returns the expected output"""
filtered_events = self.event_source.filter_out_private(events, "@me:server.org")
filtered_events = self.event_source.filter_out_private_receipts(
events, "@me:server.org"
)
self.assertEqual(filtered_events, expected_output)