MSC4140: finalised delayed events, and more

changelog.d/19038.feature

@@ -0,0 +1 @@
+Add more support for MSC4140, namely the ability to inspect sent, cancelled, or failed delayed events, aka "finalised" delayed events.

synapse/config/experimental.py

@@ -551,6 +551,21 @@ def read_config(
         # MSC4133: Custom profile fields
         self.msc4133_enabled: bool = experimental.get("msc4133_enabled", False)
 
+        # MSC4140: How many delayed events a user is allowed to have scheduled at a time.
+        self.msc4140_max_delayed_events_per_user = experimental.get(
+            "msc4140_max_delayed_events_per_user", 100
+        )
+
+        # MSC4140: How long to keep finalised delayed events in the database before deleting them.
+        self.msc4140_finalised_retention_period = self.parse_duration(
+            config.get("msc4140_finalised_retention_period", "7d")
+        )
+
+        # MSC4140: How many finalised delayed events to keep per user before deleting them.
+        self.msc4140_finalised_per_user_retention_limit = experimental.get(
+            "msc4140_finalised_per_user_retention_limit", 1000
+        )
+
         # MSC4143: Matrix RTC Transport using Livekit Backend
         self.msc4143_enabled: bool = experimental.get("msc4143_enabled", False)
 

synapse/handlers/delayed_events.py

@@ -18,12 +18,13 @@
 from twisted.internet.interfaces import IDelayedCall
 
 from synapse.api.constants import EventTypes
-from synapse.api.errors import ShadowBanError, SynapseError
+from synapse.api.errors import ShadowBanError, SynapseError, cs_error
 from synapse.api.ratelimiting import Ratelimiter
 from synapse.config.workers import MAIN_PROCESS_INSTANCE_NAME
 from synapse.logging.context import make_deferred_yieldable
 from synapse.logging.opentracing import set_tag
 from synapse.metrics import SERVER_NAME_LABEL, event_processing_positions
+from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.replication.http.delayed_events import (
     ReplicationAddedDelayedEventRestServlet,
 )
@@ -43,6 +44,7 @@
     UserID,
     create_requester,
 )
+from synapse.util.constants import MILLISECONDS_PER_SECOND, ONE_MINUTE_SECONDS
 from synapse.util.events import generate_fake_event_id
 from synapse.util.metrics import Measure
 from synapse.util.sentinel import Sentinel
@@ -125,14 +127,20 @@ async def _schedule_db_events() -> None:
         else:
             self._repl_client = ReplicationAddedDelayedEventRestServlet.make_client(hs)
 
+        if hs.config.worker.run_background_tasks:
+            self._clock.looping_call(
+                self._prune_finalised_events,
+                5 * ONE_MINUTE_SECONDS * MILLISECONDS_PER_SECOND,
+            )
+
     @property
     def _is_master(self) -> bool:
         return self._repl_client is None
 
     def notify_new_event(self) -> None:
         """
         Called when there may be more state event deltas to process,
-        which should cancel pending delayed events for the same state.
+        which should cancel scheduled delayed events for the same state.
         """
         if self._event_processing:
             return
@@ -156,8 +164,7 @@ async def _unsafe_process_new_event(self) -> None:
         room_max_stream_ordering = self._store.get_room_max_stream_ordering()
 
         # Check that there are actually any delayed events to process. If not, bail early.
-        delayed_events_count = await self._store.get_count_of_delayed_events()
-        if delayed_events_count == 0:
+        if not await self._store.has_scheduled_delayed_events():
             # There are no delayed events to process. Update the
             # `delayed_events_stream_pos` to the latest `events` stream pos and
             # exit early.
@@ -228,7 +235,7 @@ async def _unsafe_process_new_event(self) -> None:
 
     async def _handle_state_deltas(self, deltas: list[StateDelta]) -> None:
         """
-        Process current state deltas to cancel other users' pending delayed events
+        Process current state deltas to cancel other users' scheduled delayed events
         that target the same state.
         """
         # Get the senders of each delta's state event (as sender information is
@@ -316,11 +323,20 @@ async def _handle_state_deltas(self, deltas: list[StateDelta]) -> None:
                     if sender.domain == self._config.server.server_name
                     else ""
                 ),
+                finalised_ts=self._get_current_ts(),
             )
 
             if self._next_send_ts_changed(next_send_ts):
                 self._schedule_next_at_or_none(next_send_ts)
 
+    @wrap_as_background_process("_prune_finalised_events")
+    async def _prune_finalised_events(self) -> None:
+        await self._store.prune_finalised_delayed_events(
+            self._get_current_ts(),
+            self.hs.config.experimental.msc4140_finalised_retention_period,
+            self.hs.config.experimental.msc4140_finalised_per_user_retention_limit,
+        )
+
     async def add(
         self,
         requester: Requester,
@@ -380,6 +396,7 @@ async def add(
             origin_server_ts=origin_server_ts,
             content=content,
             delay=delay,
+            limit=self.hs.config.experimental.msc4140_max_delayed_events_per_user,
         )
 
         if self._repl_client is not None:
@@ -420,6 +437,7 @@ async def cancel(self, requester: Requester, delay_id: str) -> None:
         next_send_ts = await self._store.cancel_delayed_event(
             delay_id=delay_id,
             user_localpart=requester.user.localpart,
+            finalised_ts=self._get_current_ts(),
         )
 
         if self._next_send_ts_changed(next_send_ts):
@@ -477,18 +495,19 @@ async def send(self, requester: Requester, delay_id: str) -> None:
         if self._next_send_ts_changed(next_send_ts):
             self._schedule_next_at_or_none(next_send_ts)
 
-        await self._send_event(
-            DelayedEventDetails(
-                delay_id=DelayID(delay_id),
-                user_localpart=UserLocalpart(requester.user.localpart),
-                room_id=event.room_id,
-                type=event.type,
-                state_key=event.state_key,
-                origin_server_ts=event.origin_server_ts,
-                content=event.content,
-                device_id=event.device_id,
+        if event:
+            await self._send_event(
+                DelayedEventDetails(
+                    delay_id=DelayID(delay_id),
+                    user_localpart=UserLocalpart(requester.user.localpart),
+                    room_id=event.room_id,
+                    type=event.type,
+                    state_key=event.state_key,
+                    origin_server_ts=event.origin_server_ts,
+                    content=event.content,
+                    device_id=event.device_id,
+                )
             )
-        )
 
     async def _send_on_timeout(self) -> None:
         self._next_delayed_event_call = None
@@ -513,17 +532,19 @@ async def _send_events(self, events: list[DelayedEventDetails]) -> None:
                 state_info = None
             try:
                 # TODO: send in background if message event or non-conflicting state event
-                await self._send_event(event)
+                finalised_ts = await self._send_event(event)
                 if state_info is not None:
                     sent_state.add(state_info)
             except Exception:
                 logger.exception("Failed to send delayed event")
+                finalised_ts = self._get_current_ts()
 
             for room_id, event_type, state_key in sent_state:
-                await self._store.delete_processed_delayed_state_events(
+                await self._store.finalise_processed_delayed_state_events(
                     room_id=str(room_id),
                     event_type=event_type,
                     state_key=state_key,
+                    finalised_ts=finalised_ts,
                 )
 
     def _schedule_next_at_or_none(self, next_send_ts: Optional[Timestamp]) -> None:
@@ -547,21 +568,49 @@ def _schedule_next_at(self, next_send_ts: Timestamp) -> None:
         else:
             self._next_delayed_event_call.reset(delay_sec)
 
-    async def get_all_for_user(self, requester: Requester) -> list[JsonDict]:
-        """Return all pending delayed events requested by the given user."""
+    async def get_delayed_events_for_user(
+        self,
+        requester: Requester,
+        delay_ids: Optional[list[str]],
+        get_scheduled: bool,
+        get_finalised: bool,
+    ) -> dict[str, list[JsonDict]]:
+        """
+        Return all scheduled delayed events for the given user.
+
+        Args:
+            requester: The user whose delayed events to get.
+            delay_ids: The IDs of the delayed events to get, or None to get all of them.
+            get_scheduled: Whether to look up scheduled delayed events.
+            get_finalised: Whether to look up finalised delayed events.
+        """
         await self._delayed_event_mgmt_ratelimiter.ratelimit(
             requester,
             (requester.user.to_string(), requester.device_id),
         )
-        return await self._store.get_all_delayed_events_for_user(
-            requester.user.localpart
-        )
+
+        # TODO: Support Pagination stream API
+        ret = {}
+        if get_scheduled:
+            ret["scheduled"] = await self._store.get_scheduled_delayed_events_for_user(
+                requester.user.localpart,
+                delay_ids,
+            )
+        if get_finalised:
+            ret["finalised"] = await self._store.get_finalised_delayed_events_for_user(
+                requester.user.localpart,
+                delay_ids,
+                self._get_current_ts(),
+                self.hs.config.experimental.msc4140_finalised_retention_period,
+                self.hs.config.experimental.msc4140_finalised_per_user_retention_limit,
+            )
+        return ret
 
     async def _send_event(
         self,
         event: DelayedEventDetails,
         txn_id: Optional[str] = None,
-    ) -> None:
+    ) -> Timestamp:
         user_id = UserID(event.user_localpart, self._config.server.server_name)
         user_id_str = user_id.to_string()
         # Create a new requester from what data is currently available
@@ -571,6 +620,7 @@ async def _send_event(
             device_id=event.device_id,
         )
 
+        finalised_ts = None
         try:
             if event.state_key is not None and event.type == EventTypes.Member:
                 membership = event.content.get("membership")
@@ -606,18 +656,34 @@ async def _send_event(
                     txn_id=txn_id,
                 )
                 event_id = sent_event.event_id
+                if event.origin_server_ts is None:
+                    finalised_ts = Timestamp(sent_event.origin_server_ts)
         except ShadowBanError:
             event_id = generate_fake_event_id()
+            send_error = None
+        except SynapseError as e:
+            send_error = e.error_dict(None)
+        except Exception:
+            send_error = cs_error("Internal server error")
+        else:
+            send_error = None
         finally:
             # TODO: If this is a temporary error, retry. Otherwise, consider notifying clients of the failure
+            if finalised_ts is None:
+                finalised_ts = self._get_current_ts()
             try:
-                await self._store.delete_processed_delayed_event(
-                    event.delay_id, event.user_localpart
+                await self._store.finalise_processed_delayed_event(
+                    event.delay_id,
+                    event.user_localpart,
+                    send_error or event_id,
+                    finalised_ts,
                 )
             except Exception:
-                logger.exception("Failed to delete processed delayed event")
+                logger.exception("Failed to finalise processed delayed event")
 
-        set_tag("event_id", event_id)
+        if send_error is None:
+            set_tag("event_id", event_id)
+        return finalised_ts
 
     def _get_current_ts(self) -> Timestamp:
         return Timestamp(self._clock.time_msec())

synapse/rest/client/delayed_events.py

@@ -21,7 +21,12 @@
 
 from synapse.api.errors import Codes, SynapseError
 from synapse.http.server import HttpServer
-from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from synapse.http.servlet import (
+    RestServlet,
+    parse_json_object_from_request,
+    parse_string_from_args,
+    parse_strings_from_args,
+)
 from synapse.http.site import SynapseRequest
 from synapse.rest.client._base import client_patterns
 from synapse.types import JsonDict
@@ -38,6 +43,11 @@ class _UpdateDelayedEventAction(Enum):
     SEND = "send"
 
 
+class _DelayedEventStatus(Enum):
+    SCHEDULED = "scheduled"
+    FINALISED = "finalised"
+
+
 class UpdateDelayedEventServlet(RestServlet):
     PATTERNS = client_patterns(
         r"/org\.matrix\.msc4140/delayed_events/(?P<delay_id>[^/]+)$",
@@ -97,10 +107,27 @@ def __init__(self, hs: "HomeServer"):
 
     async def on_GET(self, request: SynapseRequest) -> tuple[int, JsonDict]:
         requester = await self.auth.get_user_by_req(request)
-        # TODO: Support Pagination stream API ("from" query parameter)
-        delayed_events = await self.delayed_events_handler.get_all_for_user(requester)
 
-        ret = {"delayed_events": delayed_events}
+        # twisted.web.server.Request.args is incorrectly defined as Optional[Any]
+        args: dict[bytes, list[bytes]] = request.args  # type: ignore
+        statuses = parse_strings_from_args(
+            args,
+            "status",
+            allowed_values=tuple(s.value for s in _DelayedEventStatus),
+        )
+        delay_ids = parse_strings_from_args(args, "delay_id")
+        # TODO: Support Pagination stream API
+        _from_token = parse_string_from_args(args, "from")
+
+        ret = await self.delayed_events_handler.get_delayed_events_for_user(
+            requester,
+            delay_ids,
+            statuses is None or _DelayedEventStatus.SCHEDULED.value in statuses,
+            statuses is None or _DelayedEventStatus.FINALISED.value in statuses,
+        )
+        # TODO: This is here for backwards compatibility. Remove eventually
+        if statuses is None:
+            ret["delayed_events"] = ret[_DelayedEventStatus.SCHEDULED.value]
         return 200, ret