Return read-only collections from @cached methods

changelog.d/13755.misc

@@ -0,0 +1 @@
+Re-type hint some collections as read-only.

synapse/app/phone_stats_home.py

@@ -15,7 +15,7 @@
 import math
 import resource
 import sys
-from typing import TYPE_CHECKING, List, Sized, Tuple
+from typing import TYPE_CHECKING, List, Mapping, Sized, Tuple
 
 from prometheus_client import Gauge
 
@@ -194,7 +194,7 @@ def performance_stats_init() -> None:
     @wrap_as_background_process("generate_monthly_active_users")
     async def generate_monthly_active_users() -> None:
         current_mau_count = 0
-        current_mau_count_by_service = {}
+        current_mau_count_by_service: Mapping[str, int] = {}
         reserved_users: Sized = ()
         store = hs.get_datastores().main
         if hs.config.server.limit_usage_by_mau or hs.config.server.mau_stats_only:

synapse/config/room_directory.py

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Any, List
+from typing import Any, Collection
 
 from matrix_common.regex import glob_to_regex
 
@@ -70,7 +70,7 @@ def is_alias_creation_allowed(self, user_id: str, room_id: str, alias: str) -> b
         return False
 
     def is_publishing_room_allowed(
-        self, user_id: str, room_id: str, aliases: List[str]
+        self, user_id: str, room_id: str, aliases: Collection[str]
     ) -> bool:
         """Checks if the given user is allowed to publish the room
 
@@ -122,7 +122,7 @@ def __init__(self, option_name: str, rule: JsonDict):
         except Exception as e:
             raise ConfigError("Failed to parse glob into regex") from e
 
-    def matches(self, user_id: str, room_id: str, aliases: List[str]) -> bool:
+    def matches(self, user_id: str, room_id: str, aliases: Collection[str]) -> bool:
         """Tests if this rule matches the given user_id, room_id and aliases.
 
         Args:

synapse/handlers/directory.py

@@ -14,7 +14,7 @@
 
 import logging
 import string
-from typing import TYPE_CHECKING, Iterable, List, Optional
+from typing import TYPE_CHECKING, Iterable, List, Optional, Sequence
 
 from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes
 from synapse.api.errors import (
@@ -483,6 +483,7 @@ async def edit_published_room_list(
                 )
             )
             if canonical_alias:
+                room_aliases = list(room_aliases)
                 room_aliases.append(canonical_alias)
 
             if not self.config.roomdirectory.is_publishing_room_allowed(
@@ -525,7 +526,7 @@ async def edit_published_appservice_room_list(
 
     async def get_aliases_for_room(
         self, requester: Requester, room_id: str
-    ) -> List[str]:
+    ) -> Sequence[str]:
         """
         Get a list of the aliases that currently point to this room on this server
         """

synapse/handlers/receipts.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple
+from typing import TYPE_CHECKING, Iterable, List, Optional, Sequence, Tuple
 
 from synapse.api.constants import EduTypes, ReceiptTypes
 from synapse.appservice import ApplicationService
@@ -174,7 +174,7 @@ def __init__(self, hs: "HomeServer"):
 
     @staticmethod
     def filter_out_private_receipts(
-        rooms: List[JsonDict], user_id: str
+        rooms: Sequence[JsonDict], user_id: str
     ) -> List[JsonDict]:
         """
         Filters a list of serialized receipts (as returned by /sync and /initialSync)

synapse/handlers/room.py

@@ -1872,6 +1872,6 @@ async def shutdown_room(
         return {
             "kicked_users": kicked_users,
             "failed_to_kick_users": failed_to_kick_users,
-            "local_aliases": aliases_for_room,
+            "local_aliases": list(aliases_for_room),
             "new_room_id": new_room_id,
         }

synapse/handlers/sync.py

@@ -1377,7 +1377,7 @@ async def generate_sync_result(
             one_time_key_counts = await self.store.count_e2e_one_time_keys(
                 user_id, device_id
             )
-            unused_fallback_key_types = (
+            unused_fallback_key_types = list(
                 await self.store.get_e2e_unused_fallback_key_types(user_id, device_id)
             )
 
@@ -1573,7 +1573,7 @@ async def _generate_sync_entry_for_to_device(
 
     async def _generate_sync_entry_for_account_data(
         self, sync_result_builder: "SyncResultBuilder"
-    ) -> Dict[str, Dict[str, JsonDict]]:
+    ) -> Mapping[str, Mapping[str, JsonDict]]:
         """Generates the account data portion of the sync response.
 
         Account data (called "Client Config" in the spec) can be set either globally
@@ -1608,6 +1608,7 @@ async def _generate_sync_entry_for_account_data(
             )
 
             if push_rules_changed:
+                global_account_data = dict(global_account_data)
                 global_account_data["m.push_rules"] = await self.push_rules_for_user(
                     sync_config.user
                 )
@@ -1617,6 +1618,7 @@ async def _generate_sync_entry_for_account_data(
                 account_data_by_room,
             ) = await self.store.get_account_data_for_user(sync_config.user.to_string())
 
+            global_account_data = dict(global_account_data)
             global_account_data["m.push_rules"] = await self.push_rules_for_user(
                 sync_config.user
             )
@@ -1693,7 +1695,7 @@ async def _generate_sync_entry_for_presence(
     async def _generate_sync_entry_for_rooms(
         self,
         sync_result_builder: "SyncResultBuilder",
-        account_data_by_room: Dict[str, Dict[str, JsonDict]],
+        account_data_by_room: Mapping[str, Mapping[str, JsonDict]],
     ) -> Tuple[Set[str], Set[str], Set[str], Set[str]]:
         """Generates the rooms portion of the sync response. Populates the
         `sync_result_builder` with the result.
@@ -2170,8 +2172,8 @@ async def _generate_room_entry(
         sync_result_builder: "SyncResultBuilder",
         room_builder: "RoomSyncResultBuilder",
         ephemeral: List[JsonDict],
-        tags: Optional[Dict[str, Dict[str, Any]]],
-        account_data: Dict[str, JsonDict],
+        tags: Optional[Mapping[str, Mapping[str, Any]]],
+        account_data: Mapping[str, JsonDict],
         always_include: bool = False,
     ) -> None:
         """Populates the `joined` and `archived` section of `sync_result_builder`

synapse/push/bulk_push_rule_evaluator.py

@@ -17,13 +17,13 @@
 import logging
 from typing import (
     TYPE_CHECKING,
+    AbstractSet,
     Collection,
     Dict,
     Iterable,
     List,
     Mapping,
     Optional,
-    Set,
     Tuple,
     Union,
 )
@@ -199,7 +199,7 @@ async def _get_power_levels_and_sender_level(
 
     async def _get_mutual_relations(
         self, event: EventBase, rules: Iterable[Tuple[PushRule, bool]]
-    ) -> Dict[str, Set[Tuple[str, str]]]:
+    ) -> Dict[str, AbstractSet[Tuple[str, str]]]:
         """
         Fetch event metadata for events which related to the same event as the given event.
 

synapse/push/push_rule_evaluator.py

@@ -16,14 +16,14 @@
 import logging
 import re
 from typing import (
+    AbstractSet,
     Any,
     Dict,
     List,
     Mapping,
     Optional,
     Pattern,
     Sequence,
-    Set,
     Tuple,
     Union,
 )
@@ -131,7 +131,7 @@ def __init__(
         room_member_count: int,
         sender_power_level: int,
         power_levels: Dict[str, Union[int, Dict[str, int]]],
-        relations: Dict[str, Set[Tuple[str, str]]],
+        relations: Dict[str, AbstractSet[Tuple[str, str]]],
         relations_match_enabled: bool,
     ):
         self._event = event

synapse/state/__init__.py

@@ -210,7 +210,7 @@ async def compute_state_after_events(
         return await ret.get_state(self._state_storage_controller, state_filter)
 
     async def get_current_user_ids_in_room(
-        self, room_id: str, latest_event_ids: List[str]
+        self, room_id: str, latest_event_ids: Collection[str]
     ) -> Set[str]:
         """
         Get the users IDs who are currently in a room.

synapse/storage/controllers/state.py

@@ -23,6 +23,7 @@
     List,
     Mapping,
     Optional,
+    Sequence,
     Tuple,
 )
 
@@ -523,7 +524,7 @@ async def get_current_state_event(
         )
         return state_map.get(key)
 
-    async def get_current_hosts_in_room(self, room_id: str) -> List[str]:
+    async def get_current_hosts_in_room(self, room_id: str) -> Sequence[str]:
         """Get current hosts in room based on current state."""
 
         await self._partial_state_room_tracker.await_full_state(room_id)
@@ -532,7 +533,7 @@ async def get_current_hosts_in_room(self, room_id: str) -> List[str]:
 
     async def get_users_in_room_with_profiles(
         self, room_id: str
-    ) -> Dict[str, ProfileInfo]:
+    ) -> Mapping[str, ProfileInfo]:
         """
         Get the current users in the room with their profiles.
         If the room is currently partial-stated, this will block until the room has

synapse/storage/databases/main/account_data.py

@@ -21,6 +21,7 @@
     FrozenSet,
     Iterable,
     List,
+    Mapping,
     Optional,
     Tuple,
     cast,
@@ -132,7 +133,7 @@ def get_max_account_data_stream_id(self) -> int:
     @cached()
     async def get_account_data_for_user(
         self, user_id: str
-    ) -> Tuple[Dict[str, JsonDict], Dict[str, Dict[str, JsonDict]]]:
+    ) -> Tuple[Mapping[str, JsonDict], Mapping[str, Mapping[str, JsonDict]]]:
         """Get all the client account_data for a user.
 
         Args:
@@ -198,7 +199,7 @@ async def get_global_account_data_by_type_for_user(
     @cached(num_args=2, tree=True)
     async def get_account_data_for_room(
         self, user_id: str, room_id: str
-    ) -> Dict[str, JsonDict]:
+    ) -> Mapping[str, JsonDict]:
         """Get all the client account_data for a user for a room.
 
         Args:
@@ -327,7 +328,7 @@ def get_updated_room_account_data_txn(
 
     async def get_updated_account_data_for_user(
         self, user_id: str, stream_id: int
-    ) -> Tuple[Dict[str, JsonDict], Dict[str, Dict[str, JsonDict]]]:
+    ) -> Tuple[Mapping[str, JsonDict], Mapping[str, Mapping[str, JsonDict]]]:
         """Get all the client account_data for a that's changed for a user
 
         Args:

synapse/storage/databases/main/appservice.py

@@ -14,7 +14,17 @@
 # limitations under the License.
 import logging
 import re
-from typing import TYPE_CHECKING, Any, Dict, List, Optional, Pattern, Tuple, cast
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Dict,
+    List,
+    Optional,
+    Pattern,
+    Sequence,
+    Tuple,
+    cast,
+)
 
 from synapse.appservice import (
     ApplicationService,
@@ -156,7 +166,7 @@ async def get_app_service_users_in_room(
         room_id: str,
         app_service: "ApplicationService",
         cache_context: _CacheContext,
-    ) -> List[str]:
+    ) -> Sequence[str]:
         users_in_room = await self.get_users_in_room(
             room_id, on_invalidate=cache_context.invalidate
         )

synapse/storage/databases/main/devices.py

@@ -22,6 +22,7 @@
     Dict,
     Iterable,
     List,
+    Mapping,
     Optional,
     Set,
     Tuple,
@@ -135,7 +136,9 @@ def __init__(
                 self._prune_old_outbound_device_pokes, 60 * 60 * 1000
             )
 
-    async def count_devices_by_users(self, user_ids: Optional[List[str]] = None) -> int:
+    async def count_devices_by_users(
+        self, user_ids: Optional[Collection[str]] = None
+    ) -> int:
         """Retrieve number of all devices of given users.
         Only returns number of devices that are not marked as hidden.
 
@@ -146,7 +149,7 @@ async def count_devices_by_users(self, user_ids: Optional[List[str]] = None) ->
         """
 
         def count_devices_by_users_txn(
-            txn: LoggingTransaction, user_ids: List[str]
+            txn: LoggingTransaction, user_ids: Collection[str]
         ) -> int:
             sql = """
                 SELECT count(*)
@@ -706,7 +709,7 @@ async def get_user_devices_from_cache(
                 device = await self._get_cached_user_device(user_id, device_id)
                 results.setdefault(user_id, {})[device_id] = device
             else:
-                results[user_id] = await self.get_cached_devices_for_user(user_id)
+                results[user_id] = dict(await self.get_cached_devices_for_user(user_id))
 
         set_tag("in_cache", str(results))
         set_tag("not_in_cache", str(user_ids_not_in_cache))
@@ -724,7 +727,7 @@ async def _get_cached_user_device(self, user_id: str, device_id: str) -> JsonDic
         return db_to_json(content)
 
     @cached()
-    async def get_cached_devices_for_user(self, user_id: str) -> Dict[str, JsonDict]:
+    async def get_cached_devices_for_user(self, user_id: str) -> Mapping[str, JsonDict]:
         devices = await self.db_pool.simple_select_list(
             table="device_lists_remote_cache",
             keyvalues={"user_id": user_id},

synapse/storage/databases/main/directory.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Iterable, List, Optional, Tuple
+from typing import Iterable, List, Optional, Sequence, Tuple
 
 import attr
 
@@ -74,7 +74,7 @@ async def get_room_alias_creator(self, room_alias: str) -> str:
         )
 
     @cached(max_entries=5000)
-    async def get_aliases_for_room(self, room_id: str) -> List[str]:
+    async def get_aliases_for_room(self, room_id: str) -> Sequence[str]:
         return await self.db_pool.simple_select_onecol(
             "room_aliases",
             {"room_id": room_id},