Convert internal pusher dicts to attrs classes. (#8940)

This improves type hinting and should use less memory.

synapse/push/httppusher.py

@@ -25,7 +25,7 @@ from synapse.api.constants import EventTypes
 from synapse.events import EventBase
 from synapse.logging import opentracing
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.push import Pusher, PusherConfigException
+from synapse.push import Pusher, PusherConfig, PusherConfigException
 
 from . import push_rule_evaluator, push_tools
 
@@ -62,33 +62,29 @@ class HttpPusher(Pusher):
     # This one's in ms because we compare it against the clock
     GIVE_UP_AFTER_MS = 24 * 60 * 60 * 1000
 
-    def __init__(self, hs: "HomeServer", pusherdict: Dict[str, Any]):
-        super().__init__(hs, pusherdict)
+    def __init__(self, hs: "HomeServer", pusher_config: PusherConfig):
+        super().__init__(hs, pusher_config)
         self.storage = self.hs.get_storage()
-        self.app_display_name = pusherdict["app_display_name"]
-        self.device_display_name = pusherdict["device_display_name"]
-        self.pushkey_ts = pusherdict["ts"]
-        self.data = pusherdict["data"]
-        self.last_stream_ordering = pusherdict["last_stream_ordering"]
+        self.app_display_name = pusher_config.app_display_name
+        self.device_display_name = pusher_config.device_display_name
+        self.pushkey_ts = pusher_config.ts
+        self.data = pusher_config.data
         self.backoff_delay = HttpPusher.INITIAL_BACKOFF_SEC
-        self.failing_since = pusherdict["failing_since"]
+        self.failing_since = pusher_config.failing_since
         self.timed_call = None
         self._is_processing = False
         self._group_unread_count_by_room = hs.config.push_group_unread_count_by_room
 
-        if "data" not in pusherdict:
-            raise PusherConfigException("No 'data' key for HTTP pusher")
-        self.data = pusherdict["data"]
+        self.data = pusher_config.data
+        if self.data is None:
+            raise PusherConfigException("'data' key can not be null for HTTP pusher")
 
         self.name = "%s/%s/%s" % (
-            pusherdict["user_name"],
-            pusherdict["app_id"],
-            pusherdict["pushkey"],
+            pusher_config.user_name,
+            pusher_config.app_id,
+            pusher_config.pushkey,
         )
 
-        if self.data is None:
-            raise PusherConfigException("data can not be null for HTTP pusher")
-
         # Validate that there's a URL and it is of the proper form.
         if "url" not in self.data:
             raise PusherConfigException("'url' required in data for HTTP pusher")
@@ -180,6 +176,7 @@ class HttpPusher(Pusher):
         Never call this directly: use _process which will only allow this to
         run once per pusher.
         """
+        assert self.last_stream_ordering is not None
         unprocessed = await self.store.get_unread_push_actions_for_user_in_range_for_http(
             self.user_id, self.last_stream_ordering, self.max_stream_ordering
         )
@@ -208,6 +205,7 @@ class HttpPusher(Pusher):
                 http_push_processed_counter.inc()
                 self.backoff_delay = HttpPusher.INITIAL_BACKOFF_SEC
                 self.last_stream_ordering = push_action["stream_ordering"]
+                assert self.last_stream_ordering is not None
                 pusher_still_exists = await self.store.update_pusher_last_stream_ordering_and_success(
                     self.app_id,
                     self.pushkey,
@@ -314,6 +312,8 @@ class HttpPusher(Pusher):
             #  or may do so (i.e. is encrypted so has unknown effects).
             priority = "high"
 
+        # This was checked in the __init__, but mypy doesn't seem to know that.
+        assert self.data is not None
         if self.data.get("format") == "event_id_only":
             d = {
                 "notification": {