Remove the deprecated BaseHandler. (#11005)

The shared ratelimit function was replaced with a dedicated
RequestRatelimiter class (accessible from the HomeServer
object).

Other properties were copied to each sub-class that inherited
from BaseHandler.

changelog.d/11005.misc

@@ -0,0 +1 @@
+Remove the deprecated `BaseHandler` object.

synapse/api/ratelimiting.py

@@ -17,6 +17,7 @@
 from typing import Hashable, Optional, Tuple
 
 from synapse.api.errors import LimitExceededError
+from synapse.config.ratelimiting import RateLimitConfig
 from synapse.storage.databases.main import DataStore
 from synapse.types import Requester
 from synapse.util import Clock
@@ -233,3 +234,88 @@ async def ratelimit(
             raise LimitExceededError(
                 retry_after_ms=int(1000 * (time_allowed - time_now_s))
             )
+
+
+class RequestRatelimiter:
+    def __init__(
+        self,
+        store: DataStore,
+        clock: Clock,
+        rc_message: RateLimitConfig,
+        rc_admin_redaction: Optional[RateLimitConfig],
+    ):
+        self.store = store
+        self.clock = clock
+
+        # The rate_hz and burst_count are overridden on a per-user basis
+        self.request_ratelimiter = Ratelimiter(
+            store=self.store, clock=self.clock, rate_hz=0, burst_count=0
+        )
+        self._rc_message = rc_message
+
+        # Check whether ratelimiting room admin message redaction is enabled
+        # by the presence of rate limits in the config
+        if rc_admin_redaction:
+            self.admin_redaction_ratelimiter: Optional[Ratelimiter] = Ratelimiter(
+                store=self.store,
+                clock=self.clock,
+                rate_hz=rc_admin_redaction.per_second,
+                burst_count=rc_admin_redaction.burst_count,
+            )
+        else:
+            self.admin_redaction_ratelimiter = None
+
+    async def ratelimit(
+        self,
+        requester: Requester,
+        update: bool = True,
+        is_admin_redaction: bool = False,
+    ) -> None:
+        """Ratelimits requests.
+
+        Args:
+            requester
+            update: Whether to record that a request is being processed.
+                Set to False when doing multiple checks for one request (e.g.
+                to check up front if we would reject the request), and set to
+                True for the last call for a given request.
+            is_admin_redaction: Whether this is a room admin/moderator
+                redacting an event. If so then we may apply different
+                ratelimits depending on config.
+
+        Raises:
+            LimitExceededError if the request should be ratelimited
+        """
+        user_id = requester.user.to_string()
+
+        # The AS user itself is never rate limited.
+        app_service = self.store.get_app_service_by_user_id(user_id)
+        if app_service is not None:
+            return  # do not ratelimit app service senders
+
+        messages_per_second = self._rc_message.per_second
+        burst_count = self._rc_message.burst_count
+
+        # Check if there is a per user override in the DB.
+        override = await self.store.get_ratelimit_for_user(user_id)
+        if override:
+            # If overridden with a null Hz then ratelimiting has been entirely
+            # disabled for the user
+            if not override.messages_per_second:
+                return
+
+            messages_per_second = override.messages_per_second
+            burst_count = override.burst_count
+
+        if is_admin_redaction and self.admin_redaction_ratelimiter:
+            # If we have separate config for admin redactions, use a separate
+            # ratelimiter as to not have user_ids clash
+            await self.admin_redaction_ratelimiter.ratelimit(requester, update=update)
+        else:
+            # Override rate and burst count per-user
+            await self.request_ratelimiter.ratelimit(
+                requester,
+                rate_hz=messages_per_second,
+                burst_count=burst_count,
+                update=update,
+            )

synapse/handlers/admin.py

@@ -21,18 +21,15 @@
 from synapse.types import JsonDict, RoomStreamToken, StateMap, UserID
 from synapse.visibility import filter_events_for_client
 
-from ._base import BaseHandler
-
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
 logger = logging.getLogger(__name__)
 
 
-class AdminHandler(BaseHandler):
+class AdminHandler:
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
+        self.store = hs.get_datastore()
         self.storage = hs.get_storage()
         self.state_store = self.storage.state
 

synapse/handlers/auth.py

@@ -52,7 +52,6 @@
     UserDeactivatedError,
 )
 from synapse.api.ratelimiting import Ratelimiter
-from synapse.handlers._base import BaseHandler
 from synapse.handlers.ui_auth import (
     INTERACTIVE_AUTH_CHECKERS,
     UIAuthSessionDataConstants,
@@ -186,12 +185,13 @@ class LoginTokenAttributes:
     auth_provider_id = attr.ib(type=str)
 
 
-class AuthHandler(BaseHandler):
+class AuthHandler:
     SESSION_EXPIRE_MS = 48 * 60 * 60 * 1000
 
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
+        self.store = hs.get_datastore()
+        self.auth = hs.get_auth()
+        self.clock = hs.get_clock()
         self.checkers: Dict[str, UserInteractiveAuthChecker] = {}
         for auth_checker_class in INTERACTIVE_AUTH_CHECKERS:
             inst = auth_checker_class(hs)

synapse/handlers/deactivate_account.py

@@ -19,19 +19,17 @@
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.types import Requester, UserID, create_requester
 
-from ._base import BaseHandler
-
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
 logger = logging.getLogger(__name__)
 
 
-class DeactivateAccountHandler(BaseHandler):
+class DeactivateAccountHandler:
     """Handler which deals with deactivating user accounts."""
 
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
+        self.store = hs.get_datastore()
         self.hs = hs
         self._auth_handler = hs.get_auth_handler()
         self._device_handler = hs.get_device_handler()

synapse/handlers/device.py

@@ -40,8 +40,6 @@
 from synapse.util.metrics import measure_func
 from synapse.util.retryutils import NotRetryingDestination
 
-from ._base import BaseHandler
-
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
@@ -50,14 +48,16 @@
 MAX_DEVICE_DISPLAY_NAME_LEN = 100
 
 
-class DeviceWorkerHandler(BaseHandler):
+class DeviceWorkerHandler:
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
+        self.clock = hs.get_clock()
         self.hs = hs
+        self.store = hs.get_datastore()
+        self.notifier = hs.get_notifier()
         self.state = hs.get_state_handler()
         self.state_store = hs.get_storage().state
         self._auth_handler = hs.get_auth_handler()
+        self.server_name = hs.hostname
 
     @trace
     async def get_devices_by_user(self, user_id: str) -> List[JsonDict]:

synapse/handlers/directory.py

@@ -31,18 +31,16 @@
 from synapse.storage.databases.main.directory import RoomAliasMapping
 from synapse.types import JsonDict, Requester, RoomAlias, UserID, get_domain_from_id
 
-from ._base import BaseHandler
-
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
 logger = logging.getLogger(__name__)
 
 
-class DirectoryHandler(BaseHandler):
+class DirectoryHandler:
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
+        self.auth = hs.get_auth()
+        self.hs = hs
         self.state = hs.get_state_handler()
         self.appservice_handler = hs.get_application_service_handler()
         self.event_creation_handler = hs.get_event_creation_handler()
@@ -51,6 +49,7 @@ def __init__(self, hs: "HomeServer"):
         self.enable_room_list_search = hs.config.roomdirectory.enable_room_list_search
         self.require_membership = hs.config.server.require_membership_for_aliases
         self.third_party_event_rules = hs.get_third_party_event_rules()
+        self.server_name = hs.hostname
 
         self.federation = hs.get_federation_client()
         hs.get_federation_registry().register_query_handler(

synapse/handlers/events.py

@@ -25,20 +25,18 @@
 from synapse.types import JsonDict, UserID
 from synapse.visibility import filter_events_for_client
 
-from ._base import BaseHandler
-
 if TYPE_CHECKING:
     from synapse.server import HomeServer
 
 
 logger = logging.getLogger(__name__)
 
 
-class EventStreamHandler(BaseHandler):
+class EventStreamHandler:
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
-
+        self.store = hs.get_datastore()
         self.clock = hs.get_clock()
+        self.hs = hs
 
         self.notifier = hs.get_notifier()
         self.state = hs.get_state_handler()
@@ -138,9 +136,9 @@ async def get_stream(
             return chunk
 
 
-class EventHandler(BaseHandler):
+class EventHandler:
     def __init__(self, hs: "HomeServer"):
-        super().__init__(hs)
+        self.store = hs.get_datastore()
         self.storage = hs.get_storage()
 
     async def get_event(