Fix hidden DMs not reappearing live, and the recurring idle-transaction leak

Two related fixes:

1. A hidden DM's un-hide-on-new-message path only cleared
   RoomMembership.hidden_at in the DB -- it never told an already-open
   client to refresh. The only existing signal for that room
   (unread_update) does setRooms(prev => prev.map(...)), which is a
   no-op for a room that isn't in `prev` at all -- exactly what a
   hidden DM is. Now broadcasts the same room_added signal a brand new
   DM gets (via UPDATE ... RETURNING to know exactly who was
   un-hidden), reusing the fix already established for that class of
   bug.

2. While debugging #1's test, found the actual root cause behind the
   deploy-blocking migrations from earlier this session: every
   WebSocket connection shares one AsyncSession for its entire
   lifetime, and SQLAlchemy opens a transaction implicitly on first
   use. Nothing ever committed it -- not the initial auth lookup, not
   any of the several read-then-continue branches in the message loop
   (join/message/edit/reaction all check membership this way). A
   connection that's just sitting open (which for a real user can be
   hours) was holding that transaction open the entire time, which is
   exactly what blocked ALTER TABLE twice in production this session
   (confirmed both times via pg_stat_activity -- idle in transaction
   for 30+ minutes on this exact query shape). Now commits once after
   connection setup and once after every frame via a try/finally
   wrapping the whole dispatch, so no exit path (including the many
   `continue`s) can leave a transaction open while idling on the next
   receive_json().

Verified end-to-end in the browser (a hidden DM reappears in an
already-open tab with zero reload when the other person messages
again) and via a new WS-level test reproducing the exact scenario.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This commit is contained in:
2026-08-19 17:20:00 -06:00
co-authored by Claude Sonnet 5
parent 766883c992
commit 1d9fe25410
3 changed files with 212 additions and 144 deletions
+162 -142
View File
@@ -89,157 +89,177 @@ async def chat_endpoint(websocket: WebSocket, db: AsyncSession = Depends(get_db)
# visible.
if await global_presence.connect(user.id):
await broadcast_member_updated(db, broadcaster, user.id)
# This session is shared for the connection's entire lifetime (which can
# be hours) -- SQLAlchemy opens a transaction implicitly on first use,
# and every read above (the auth lookup, broadcast_member_updated's own
# query) leaves it open with nothing to ever close it otherwise. Left
# uncommitted, that transaction sits "idle in transaction" holding locks
# for as long as the socket stays open -- confirmed in production
# blocking unrelated schema migrations on the same tables for 30+
# minutes. Committing here, and again after every frame below, means
# the connection is never sitting on an open transaction while merely
# waiting for the next one.
await db.commit()
try:
while True:
raw = await websocket.receive_json()
try:
envelope = ClientEnvelope.model_validate(raw)
except ValidationError:
await websocket.send_json({"type": "error", "detail": "Malformed message"})
continue
if envelope.type == "join":
if envelope.room_id is None:
await websocket.send_json({"type": "error", "detail": "room_id required"})
continue
if not await _is_room_member(db, envelope.room_id, user.id):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
manager.join(envelope.room_id, websocket)
await presence.join(envelope.room_id, user.id)
joined_rooms.add(envelope.room_id)
await websocket.send_json({"type": "joined", "room_id": str(envelope.room_id)})
elif envelope.type == "leave":
if envelope.room_id is None:
await websocket.send_json({"type": "error", "detail": "room_id required"})
continue
manager.leave(envelope.room_id, websocket)
await presence.leave(envelope.room_id, user.id)
joined_rooms.discard(envelope.room_id)
elif envelope.type == "message":
if envelope.room_id is None or (
not envelope.content
and envelope.image_id is None
and envelope.file_id is None
):
await websocket.send_json(
{
"type": "error",
"detail": "room_id and content or image_id or file_id required",
}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
image_id = None
if envelope.image_id is not None:
image = await db.get(MessageImage, envelope.image_id)
if image is None or image.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Invalid image"})
continue
image_id = image.id
file_id = None
if envelope.file_id is not None:
message_file = await db.get(MessageFile, envelope.file_id)
if message_file is None or message_file.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Invalid file"})
continue
file_id = message_file.id
message = await create_message(
db, envelope.room_id, user.id, envelope.content, image_id, file_id
)
# Sending implies having seen the room as of now -- without
# this, GET /rooms/mine would show the sender's own room as
# unread the instant they send into it (last_read_at isn't
# otherwise bumped until the frontend's own message echo
# triggers a mark-read call, which is a real but avoidable
# race). Deliberately not done in create_message() itself:
# the incoming-webhook path also calls it, and a webhook's
# attributed sender may not actually be watching.
await mark_room_read(db, envelope.room_id, user.id)
await broadcast_new_message(db, broadcaster, presence, envelope.room_id, message, user)
elif envelope.type == "edit":
if envelope.room_id is None or envelope.message_id is None or not envelope.content:
await websocket.send_json(
{"type": "error", "detail": "room_id, message_id, and content required"}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
try:
message = await edit_message(db, envelope.message_id, user.id, envelope.content)
except MessageNotFoundError:
await websocket.send_json({"type": "error", "detail": "Message not found"})
envelope = ClientEnvelope.model_validate(raw)
except ValidationError:
await websocket.send_json({"type": "error", "detail": "Malformed message"})
continue
except NotMessageAuthorError:
await websocket.send_json(
{"type": "error", "detail": "You can only edit your own messages"}
)
continue
await broadcast_message_update(db, broadcaster, envelope.room_id, message)
elif envelope.type == "reaction":
if (
envelope.room_id is None
or envelope.message_id is None
or not envelope.emoji
or len(envelope.emoji) > 8
):
await websocket.send_json(
{"type": "error", "detail": "room_id, message_id, and emoji required"}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
target_message = await db.get(Message, envelope.message_id)
if target_message is None or target_message.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Message not found"})
continue
reactions = await toggle_reaction(db, envelope.message_id, user.id, envelope.emoji)
await broadcast_reaction_update(
broadcaster, envelope.room_id, envelope.message_id, reactions
)
if envelope.type == "join":
if envelope.room_id is None:
await websocket.send_json({"type": "error", "detail": "room_id required"})
continue
if not await _is_room_member(db, envelope.room_id, user.id):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
manager.join(envelope.room_id, websocket)
await presence.join(envelope.room_id, user.id)
joined_rooms.add(envelope.room_id)
await websocket.send_json({"type": "joined", "room_id": str(envelope.room_id)})
else:
await websocket.send_json(
{"type": "error", "detail": f"Unknown message type: {envelope.type}"}
)
elif envelope.type == "leave":
if envelope.room_id is None:
await websocket.send_json({"type": "error", "detail": "room_id required"})
continue
manager.leave(envelope.room_id, websocket)
await presence.leave(envelope.room_id, user.id)
joined_rooms.discard(envelope.room_id)
elif envelope.type == "message":
if envelope.room_id is None or (
not envelope.content
and envelope.image_id is None
and envelope.file_id is None
):
await websocket.send_json(
{
"type": "error",
"detail": "room_id and content or image_id or file_id required",
}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
image_id = None
if envelope.image_id is not None:
image = await db.get(MessageImage, envelope.image_id)
if image is None or image.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Invalid image"})
continue
image_id = image.id
file_id = None
if envelope.file_id is not None:
message_file = await db.get(MessageFile, envelope.file_id)
if message_file is None or message_file.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Invalid file"})
continue
file_id = message_file.id
message = await create_message(
db, envelope.room_id, user.id, envelope.content, image_id, file_id
)
# Sending implies having seen the room as of now --
# without this, GET /rooms/mine would show the sender's
# own room as unread the instant they send into it
# (last_read_at isn't otherwise bumped until the
# frontend's own message echo triggers a mark-read
# call, which is a real but avoidable race).
# Deliberately not done in create_message() itself: the
# incoming-webhook path also calls it, and a webhook's
# attributed sender may not actually be watching.
await mark_room_read(db, envelope.room_id, user.id)
await broadcast_new_message(db, broadcaster, presence, envelope.room_id, message, user)
elif envelope.type == "edit":
if envelope.room_id is None or envelope.message_id is None or not envelope.content:
await websocket.send_json(
{"type": "error", "detail": "room_id, message_id, and content required"}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
try:
message = await edit_message(db, envelope.message_id, user.id, envelope.content)
except MessageNotFoundError:
await websocket.send_json({"type": "error", "detail": "Message not found"})
continue
except NotMessageAuthorError:
await websocket.send_json(
{"type": "error", "detail": "You can only edit your own messages"}
)
continue
await broadcast_message_update(db, broadcaster, envelope.room_id, message)
elif envelope.type == "reaction":
if (
envelope.room_id is None
or envelope.message_id is None
or not envelope.emoji
or len(envelope.emoji) > 8
):
await websocket.send_json(
{"type": "error", "detail": "room_id, message_id, and emoji required"}
)
continue
if _missing_scope(api_token, "write:messages"):
await websocket.send_json(
{"type": "error", "detail": "Token missing required scope: write:messages"}
)
continue
if envelope.room_id not in joined_rooms or not await _is_room_member(
db, envelope.room_id, user.id
):
await websocket.send_json(
{"type": "error", "detail": "Not a member of this room"}
)
continue
target_message = await db.get(Message, envelope.message_id)
if target_message is None or target_message.room_id != envelope.room_id:
await websocket.send_json({"type": "error", "detail": "Message not found"})
continue
reactions = await toggle_reaction(db, envelope.message_id, user.id, envelope.emoji)
await broadcast_reaction_update(
broadcaster, envelope.room_id, envelope.message_id, reactions
)
else:
await websocket.send_json(
{"type": "error", "detail": f"Unknown message type: {envelope.type}"}
)
finally:
# See the comment on the pre-loop commit above -- guarantees
# every single frame, on every exit path (including the
# many `continue`s above, which still run a `finally`
# before actually looping), leaves nothing open while this
# blocks on the next receive_json().
await db.commit()
except WebSocketDisconnect:
pass