Send some ephemeral events to appservices (#8437)

Optionally sends typing, presence, and read receipt information to appservices.

synapse/handlers/appservice.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+from typing import Dict, List, Optional
 
 from prometheus_client import Counter
 
@@ -21,13 +22,16 @@ from twisted.internet import defer
 
 import synapse
 from synapse.api.constants import EventTypes
+from synapse.appservice import ApplicationService
+from synapse.events import EventBase
+from synapse.handlers.presence import format_user_presence_state
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.metrics import (
     event_processing_loop_counter,
     event_processing_loop_room_count,
 )
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.types import RoomStreamToken
+from synapse.types import Collection, JsonDict, RoomStreamToken, UserID
 from synapse.util.metrics import Measure
 
 logger = logging.getLogger(__name__)
@@ -44,6 +48,7 @@ class ApplicationServicesHandler:
         self.started_scheduler = False
         self.clock = hs.get_clock()
         self.notify_appservices = hs.config.notify_appservices
+        self.event_sources = hs.get_event_sources()
 
         self.current_max = 0
         self.is_processing = False
@@ -82,7 +87,7 @@ class ApplicationServicesHandler:
                     if not events:
                         break
 
-                    events_by_room = {}
+                    events_by_room = {}  # type: Dict[str, List[EventBase]]
                     for event in events:
                         events_by_room.setdefault(event.room_id, []).append(event)
 
@@ -161,6 +166,104 @@ class ApplicationServicesHandler:
             finally:
                 self.is_processing = False
 
+    async def notify_interested_services_ephemeral(
+        self, stream_key: str, new_token: Optional[int], users: Collection[UserID] = [],
+    ):
+        """This is called by the notifier in the background
+        when a ephemeral event handled by the homeserver.
+
+        This will determine which appservices
+        are interested in the event, and submit them.
+
+        Events will only be pushed to appservices
+        that have opted into ephemeral events
+
+        Args:
+            stream_key: The stream the event came from.
+            new_token: The latest stream token
+            users: The user(s) involved with the event.
+        """
+        services = [
+            service
+            for service in self.store.get_app_services()
+            if service.supports_ephemeral
+        ]
+        if not services or not self.notify_appservices:
+            return
+        logger.info("Checking interested services for %s" % (stream_key))
+        with Measure(self.clock, "notify_interested_services_ephemeral"):
+            for service in services:
+                # Only handle typing if we have the latest token
+                if stream_key == "typing_key" and new_token is not None:
+                    events = await self._handle_typing(service, new_token)
+                    if events:
+                        self.scheduler.submit_ephemeral_events_for_as(service, events)
+                    # We don't persist the token for typing_key for performance reasons
+                elif stream_key == "receipt_key":
+                    events = await self._handle_receipts(service)
+                    if events:
+                        self.scheduler.submit_ephemeral_events_for_as(service, events)
+                        await self.store.set_type_stream_id_for_appservice(
+                            service, "read_receipt", new_token
+                        )
+                elif stream_key == "presence_key":
+                    events = await self._handle_presence(service, users)
+                    if events:
+                        self.scheduler.submit_ephemeral_events_for_as(service, events)
+                        await self.store.set_type_stream_id_for_appservice(
+                            service, "presence", new_token
+                        )
+
+    async def _handle_typing(self, service: ApplicationService, new_token: int):
+        typing_source = self.event_sources.sources["typing"]
+        # Get the typing events from just before current
+        typing, _ = await typing_source.get_new_events_as(
+            service=service,
+            # For performance reasons, we don't persist the previous
+            # token in the DB and instead fetch the latest typing information
+            # for appservices.
+            from_key=new_token - 1,
+        )
+        return typing
+
+    async def _handle_receipts(self, service: ApplicationService):
+        from_key = await self.store.get_type_stream_id_for_appservice(
+            service, "read_receipt"
+        )
+        receipts_source = self.event_sources.sources["receipt"]
+        receipts, _ = await receipts_source.get_new_events_as(
+            service=service, from_key=from_key
+        )
+        return receipts
+
+    async def _handle_presence(
+        self, service: ApplicationService, users: Collection[UserID]
+    ):
+        events = []  # type: List[JsonDict]
+        presence_source = self.event_sources.sources["presence"]
+        from_key = await self.store.get_type_stream_id_for_appservice(
+            service, "presence"
+        )
+        for user in users:
+            interested = await service.is_interested_in_presence(user, self.store)
+            if not interested:
+                continue
+            presence_events, _ = await presence_source.get_new_events(
+                user=user, service=service, from_key=from_key,
+            )
+            time_now = self.clock.time_msec()
+            presence_events = [
+                {
+                    "type": "m.presence",
+                    "sender": event.user_id,
+                    "content": format_user_presence_state(
+                        event, time_now, include_user_id=False
+                    ),
+                }
+                for event in presence_events
+            ]
+            events = events + presence_events
+
     async def query_user_exists(self, user_id):
         """Check if any application service knows this user_id exists.
 
@@ -223,7 +326,7 @@ class ApplicationServicesHandler:
 
     async def get_3pe_protocols(self, only_protocol=None):
         services = self.store.get_app_services()
-        protocols = {}
+        protocols = {}  # type: Dict[str, List[JsonDict]]
 
         # Collect up all the individual protocol responses out of the ASes
         for s in services: