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.

3 files changed, 46 insertions, 17 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(
diff --git a/tests/replication/slave/storage/test_events.py b/tests/replication/slave/storage/test_events.py
index 6d3d4afe52..531a0db2d0 100644
--- a/tests/replication/slave/storage/test_events.py
+++ b/tests/replication/slave/storage/test_events.py
@@ -15,7 +15,9 @@ import logging
 from typing import Iterable, Optional
 
 from canonicaljson import encode_canonical_json
+from parameterized import parameterized
 
+from synapse.api.constants import ReceiptTypes
 from synapse.api.room_versions import RoomVersions
 from synapse.events import FrozenEvent, _EventInternalMetadata, make_event_from_dict
 from synapse.handlers.room import RoomEventSource
@@ -156,17 +158,26 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
             ],
         )
 
-    def test_push_actions_for_user(self):
+    @parameterized.expand([(True,), (False,)])
+    def test_push_actions_for_user(self, send_receipt: bool):
         self.persist(type="m.room.create", key="", creator=USER_ID)
-        self.persist(type="m.room.join", key=USER_ID, membership="join")
+        self.persist(type="m.room.member", key=USER_ID, membership="join")
         self.persist(
-            type="m.room.join", sender=USER_ID, key=USER_ID_2, membership="join"
+            type="m.room.member", sender=USER_ID, key=USER_ID_2, membership="join"
         )
         event1 = self.persist(type="m.room.message", msgtype="m.text", body="hello")
         self.replicate()
+
+        if send_receipt:
+            self.get_success(
+                self.master_store.insert_receipt(
+                    ROOM_ID, ReceiptTypes.READ, USER_ID_2, [event1.event_id], {}
+                )
+            )
+
         self.check(
             "get_unread_event_push_actions_by_room_for_user",
-            [ROOM_ID, USER_ID_2, event1.event_id],
+            [ROOM_ID, USER_ID_2],
             NotifCounts(highlight_count=0, unread_count=0, notify_count=0),
         )
 
@@ -179,7 +190,7 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
         self.replicate()
         self.check(
             "get_unread_event_push_actions_by_room_for_user",
-            [ROOM_ID, USER_ID_2, event1.event_id],
+            [ROOM_ID, USER_ID_2],
             NotifCounts(highlight_count=0, unread_count=0, notify_count=1),
         )
 
@@ -194,7 +205,7 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
         self.replicate()
         self.check(
             "get_unread_event_push_actions_by_room_for_user",
-            [ROOM_ID, USER_ID_2, event1.event_id],
+            [ROOM_ID, USER_ID_2],
             NotifCounts(highlight_count=1, unread_count=0, notify_count=2),
         )
 
diff --git a/tests/storage/test_event_push_actions.py b/tests/storage/test_event_push_actions.py
index 0f9add4841..4273524c4c 100644
--- a/tests/storage/test_event_push_actions.py
+++ b/tests/storage/test_event_push_actions.py
@@ -51,10 +51,16 @@ class EventPushActionsStoreTestCase(HomeserverTestCase):
         room_id = "!foo:example.com"
         user_id = "@user1235:example.com"
 
+        last_read_stream_ordering = [0]
+
         def _assert_counts(noitf_count, highlight_count):
             counts = self.get_success(
                 self.store.db_pool.runInteraction(
-                    "", self.store._get_unread_counts_by_pos_txn, room_id, user_id, 0
+                    "",
+                    self.store._get_unread_counts_by_pos_txn,
+                    room_id,
+                    user_id,
+                    last_read_stream_ordering[0],
                 )
             )
             self.assertEqual(
@@ -98,6 +104,7 @@ class EventPushActionsStoreTestCase(HomeserverTestCase):
             )
 
         def _mark_read(stream, depth):
+            last_read_stream_ordering[0] = stream
             self.get_success(
                 self.store.db_pool.runInteraction(
                     "",
@@ -144,8 +151,19 @@ class EventPushActionsStoreTestCase(HomeserverTestCase):
         _assert_counts(1, 1)
         _rotate(9)
         _assert_counts(1, 1)
-        _rotate(10)
-        _assert_counts(1, 1)
+
+        # Check that adding another notification and rotating after highlight
+        # works.
+        _inject_actions(10, PlAIN_NOTIF)
+        _rotate(11)
+        _assert_counts(2, 1)
+
+        # Check that sending read receipts at different points results in the
+        # right counts.
+        _mark_read(8, 8)
+        _assert_counts(1, 0)
+        _mark_read(10, 10)
+        _assert_counts(0, 0)
 
     def test_find_first_stream_ordering_after_ts(self):
         def add_event(so, ts):