Add basic tests for sync/pagination with vector clock tokens. (#8488)

These are tests for #8439

changelog.d/8488.misc

@@ -0,0 +1 @@
+Allow events to be sent to clients sooner when using sharded event persisters.

tests/replication/test_sharded_event_persister.py

@@ -14,8 +14,12 @@
 # limitations under the License.
 import logging
 
+from mock import patch
+
+from synapse.api.room_versions import RoomVersion
 from synapse.rest import admin
 from synapse.rest.client.v1 import login, room
+from synapse.rest.client.v2_alpha import sync
 
 from tests.replication._base import BaseMultiWorkerStreamTestCase
 from tests.utils import USE_POSTGRES_FOR_TESTS
@@ -36,6 +40,7 @@ class EventPersisterShardTestCase(BaseMultiWorkerStreamTestCase):
         admin.register_servlets_for_client_rest_resource,
         room.register_servlets,
         login.register_servlets,
+        sync.register_servlets,
     ]
 
     def prepare(self, reactor, clock, hs):
@@ -43,6 +48,9 @@ class EventPersisterShardTestCase(BaseMultiWorkerStreamTestCase):
         self.other_user_id = self.register_user("otheruser", "pass")
         self.other_access_token = self.login("otheruser", "pass")
 
+        self.room_creator = self.hs.get_room_creation_handler()
+        self.store = hs.get_datastore()
+
     def default_config(self):
         conf = super().default_config()
         conf["redis"] = {"enabled": "true"}
@@ -53,6 +61,29 @@ class EventPersisterShardTestCase(BaseMultiWorkerStreamTestCase):
         }
         return conf
 
+    def _create_room(self, room_id: str, user_id: str, tok: str):
+        """Create a room with given room_id
+        """
+
+        # We control the room ID generation by patching out the
+        # `_generate_room_id` method
+        async def generate_room(
+            creator_id: str, is_public: bool, room_version: RoomVersion
+        ):
+            await self.store.store_room(
+                room_id=room_id,
+                room_creator_user_id=creator_id,
+                is_public=is_public,
+                room_version=room_version,
+            )
+            return room_id
+
+        with patch(
+            "synapse.handlers.room.RoomCreationHandler._generate_room_id"
+        ) as mock:
+            mock.side_effect = generate_room
+            self.helper.create_room_as(user_id, tok=tok)
+
     def test_basic(self):
         """Simple test to ensure that multiple rooms can be created and joined,
         and that different rooms get handled by different instances.
@@ -100,3 +131,189 @@ class EventPersisterShardTestCase(BaseMultiWorkerStreamTestCase):
 
         self.assertTrue(persisted_on_1)
         self.assertTrue(persisted_on_2)
+
+    def test_vector_clock_token(self):
+        """Tests that using a stream token with a vector clock component works
+        correctly with basic /sync and /messages usage.
+        """
+
+        self.make_worker_hs(
+            "synapse.app.generic_worker", {"worker_name": "worker1"},
+        )
+
+        worker_hs2 = self.make_worker_hs(
+            "synapse.app.generic_worker", {"worker_name": "worker2"},
+        )
+
+        sync_hs = self.make_worker_hs(
+            "synapse.app.generic_worker", {"worker_name": "sync"},
+        )
+
+        # Specially selected room IDs that get persisted on different workers.
+        room_id1 = "!foo:test"
+        room_id2 = "!baz:test"
+
+        self.assertEqual(
+            self.hs.config.worker.events_shard_config.get_instance(room_id1), "worker1"
+        )
+        self.assertEqual(
+            self.hs.config.worker.events_shard_config.get_instance(room_id2), "worker2"
+        )
+
+        user_id = self.register_user("user", "pass")
+        access_token = self.login("user", "pass")
+
+        store = self.hs.get_datastore()
+
+        # Create two room on the different workers.
+        self._create_room(room_id1, user_id, access_token)
+        self._create_room(room_id2, user_id, access_token)
+
+        # The other user joins
+        self.helper.join(
+            room=room_id1, user=self.other_user_id, tok=self.other_access_token
+        )
+        self.helper.join(
+            room=room_id2, user=self.other_user_id, tok=self.other_access_token
+        )
+
+        # Do an initial sync so that we're up to date.
+        request, channel = self.make_request("GET", "/sync", access_token=access_token)
+        self.render_on_worker(sync_hs, request)
+        next_batch = channel.json_body["next_batch"]
+
+        # We now gut wrench into the events stream MultiWriterIdGenerator on
+        # worker2 to mimic it getting stuck persisting an event. This ensures
+        # that when we send an event on worker1 we end up in a state where
+        # worker2 events stream position lags that on worker1, resulting in a
+        # RoomStreamToken with a non-empty instance map component.
+        #
+        # Worker2's event stream position will not advance until we call
+        # __aexit__ again.
+        actx = worker_hs2.get_datastore()._stream_id_gen.get_next()
+        self.get_success(actx.__aenter__())
+
+        response = self.helper.send(room_id1, body="Hi!", tok=self.other_access_token)
+        first_event_in_room1 = response["event_id"]
+
+        # Assert that the current stream token has an instance map component, as
+        # we are trying to test vector clock tokens.
+        room_stream_token = store.get_room_max_token()
+        self.assertNotEqual(len(room_stream_token.instance_map), 0)
+
+        # Check that syncing still gets the new event, despite the gap in the
+        # stream IDs.
+        request, channel = self.make_request(
+            "GET", "/sync?since={}".format(next_batch), access_token=access_token
+        )
+        self.render_on_worker(sync_hs, request)
+
+        # We should only see the new event and nothing else
+        self.assertIn(room_id1, channel.json_body["rooms"]["join"])
+        self.assertNotIn(room_id2, channel.json_body["rooms"]["join"])
+
+        events = channel.json_body["rooms"]["join"][room_id1]["timeline"]["events"]
+        self.assertListEqual(
+            [first_event_in_room1], [event["event_id"] for event in events]
+        )
+
+        # Get the next batch and makes sure its a vector clock style token.
+        vector_clock_token = channel.json_body["next_batch"]
+        self.assertTrue(vector_clock_token.startswith("m"))
+
+        # Now that we've got a vector clock token we finish the fake persisting
+        # an event we started above.
+        self.get_success(actx.__aexit__(None, None, None))
+
+        # Now try and send an event to the other rooom so that we can test that
+        # the vector clock style token works as a `since` token.
+        response = self.helper.send(room_id2, body="Hi!", tok=self.other_access_token)
+        first_event_in_room2 = response["event_id"]
+
+        request, channel = self.make_request(
+            "GET",
+            "/sync?since={}".format(vector_clock_token),
+            access_token=access_token,
+        )
+        self.render_on_worker(sync_hs, request)
+
+        self.assertNotIn(room_id1, channel.json_body["rooms"]["join"])
+        self.assertIn(room_id2, channel.json_body["rooms"]["join"])
+
+        events = channel.json_body["rooms"]["join"][room_id2]["timeline"]["events"]
+        self.assertListEqual(
+            [first_event_in_room2], [event["event_id"] for event in events]
+        )
+
+        next_batch = channel.json_body["next_batch"]
+
+        # We also want to test that the vector clock style token works with
+        # pagination. We do this by sending a couple of new events into the room
+        # and syncing again to get a prev_batch token for each room, then
+        # paginating from there back to the vector clock token.
+        self.helper.send(room_id1, body="Hi again!", tok=self.other_access_token)
+        self.helper.send(room_id2, body="Hi again!", tok=self.other_access_token)
+
+        request, channel = self.make_request(
+            "GET", "/sync?since={}".format(next_batch), access_token=access_token
+        )
+        self.render_on_worker(sync_hs, request)
+
+        prev_batch1 = channel.json_body["rooms"]["join"][room_id1]["timeline"][
+            "prev_batch"
+        ]
+        prev_batch2 = channel.json_body["rooms"]["join"][room_id2]["timeline"][
+            "prev_batch"
+        ]
+
+        # Paginating back in the first room should not produce any results, as
+        # no events have happened in it. This tests that we are correctly
+        # filtering results based on the vector clock portion.
+        request, channel = self.make_request(
+            "GET",
+            "/rooms/{}/messages?from={}&to={}&dir=b".format(
+                room_id1, prev_batch1, vector_clock_token
+            ),
+            access_token=access_token,
+        )
+        self.render_on_worker(sync_hs, request)
+        self.assertListEqual([], channel.json_body["chunk"])
+
+        # Paginating back on the second room should produce the first event
+        # again. This tests that pagination isn't completely broken.
+        request, channel = self.make_request(
+            "GET",
+            "/rooms/{}/messages?from={}&to={}&dir=b".format(
+                room_id2, prev_batch2, vector_clock_token
+            ),
+            access_token=access_token,
+        )
+        self.render_on_worker(sync_hs, request)
+        self.assertEqual(len(channel.json_body["chunk"]), 1)
+        self.assertEqual(
+            channel.json_body["chunk"][0]["event_id"], first_event_in_room2
+        )
+
+        # Paginating forwards should give the same results
+        request, channel = self.make_request(
+            "GET",
+            "/rooms/{}/messages?from={}&to={}&dir=f".format(
+                room_id1, vector_clock_token, prev_batch1
+            ),
+            access_token=access_token,
+        )
+        self.render_on_worker(sync_hs, request)
+        self.assertListEqual([], channel.json_body["chunk"])
+
+        request, channel = self.make_request(
+            "GET",
+            "/rooms/{}/messages?from={}&to={}&dir=f".format(
+                room_id2, vector_clock_token, prev_batch2,
+            ),
+            access_token=access_token,
+        )
+        self.render_on_worker(sync_hs, request)
+        self.assertEqual(len(channel.json_body["chunk"]), 1)
+        self.assertEqual(
+            channel.json_body["chunk"][0]["event_id"], first_event_in_room2
+        )

tests/unittest.py

@@ -20,7 +20,7 @@ import hmac
 import inspect
 import logging
 import time
-from typing import Optional, Tuple, Type, TypeVar, Union
+from typing import Optional, Tuple, Type, TypeVar, Union, overload
 
 from mock import Mock, patch
 
@@ -364,6 +364,36 @@ class HomeserverTestCase(TestCase):
         Function to optionally be overridden in subclasses.
         """
 
+    # Annoyingly mypy doesn't seem to pick up the fact that T is SynapseRequest
+    # when the `request` arg isn't given, so we define an explicit override to
+    # cover that case.
+    @overload
+    def make_request(
+        self,
+        method: Union[bytes, str],
+        path: Union[bytes, str],
+        content: Union[bytes, dict] = b"",
+        access_token: Optional[str] = None,
+        shorthand: bool = True,
+        federation_auth_origin: str = None,
+        content_is_form: bool = False,
+    ) -> Tuple[SynapseRequest, FakeChannel]:
+        ...
+
+    @overload
+    def make_request(
+        self,
+        method: Union[bytes, str],
+        path: Union[bytes, str],
+        content: Union[bytes, dict] = b"",
+        access_token: Optional[str] = None,
+        request: Type[T] = SynapseRequest,
+        shorthand: bool = True,
+        federation_auth_origin: str = None,
+        content_is_form: bool = False,
+    ) -> Tuple[T, FakeChannel]:
+        ...
+
     def make_request(
         self,
         method: Union[bytes, str],