Speed up `get_unread_event_push_actions_by_room` (#13005)

Fixes #11887 hopefully.

The core change here is that `event_push_summary` now holds a summary of counts up until a much more recent point, meaning that the range of rows we need to count in `event_push_actions` is much smaller.

This needs two major changes:
1. When we get a receipt we need to recalculate `event_push_summary` rather than just delete it
2. The logic for deleting `event_push_actions` is now divorced from calculating `event_push_summary`.

In future it would be good to calculate `event_push_summary` while we persist a new event (it should just be a case of adding one to the relevant rows in `event_push_summary`), as that will further simplify the get counts logic and remove the need for us to periodically update `event_push_summary` in a background job.

1 files changed, 8 insertions, 8 deletions

diff --git a/tests/push/test_http.py b/tests/push/test_http.py
index ba158f5d93..d9c68cdd2d 100644
--- a/tests/push/test_http.py
+++ b/tests/push/test_http.py
@@ -577,7 +577,7 @@ class HTTPPusherTests(HomeserverTestCase):
         # Carry out our option-value specific test
         #
         # This push should still only contain an unread count of 1 (for 1 unread room)
-        self._check_push_attempt(6, 1)
+        self._check_push_attempt(7, 1)
 
     @override_config({"push": {"group_unread_count_by_room": False}})
     def test_push_unread_count_message_count(self) -> None:
@@ -591,7 +591,7 @@ class HTTPPusherTests(HomeserverTestCase):
         #
         # We're counting every unread message, so there should now be 3 since the
         # last read receipt
-        self._check_push_attempt(6, 3)
+        self._check_push_attempt(7, 3)
 
     def _test_push_unread_count(self) -> None:
         """
@@ -641,18 +641,18 @@ class HTTPPusherTests(HomeserverTestCase):
         response = self.helper.send(
             room_id, body="Hello there!", tok=other_access_token
         )
-        # To get an unread count, the user who is getting notified has to have a read
-        # position in the room. We'll set the read position to this event in a moment
+
         first_message_event_id = response["event_id"]
 
         expected_push_attempts = 1
-        self._check_push_attempt(expected_push_attempts, 0)
+        self._check_push_attempt(expected_push_attempts, 1)
 
         self._send_read_request(access_token, first_message_event_id, room_id)
 
-        # Unread count has not changed. Therefore, ensure that read request does not
-        # trigger a push notification.
-        self.assertEqual(len(self.push_attempts), 1)
+        # Unread count has changed. Therefore, ensure that read request triggers
+        # a push notification.
+        expected_push_attempts += 1
+        self.assertEqual(len(self.push_attempts), expected_push_attempts)
 
         # Send another message
         response2 = self.helper.send(