Merge commit '5c03134d0' into anoa/dinsic_release_1_21_x

* commit '5c03134d0':
  Convert additional database code to async/await. (#8195)
  Define StateMap as immutable and add a MutableStateMap type. (#8183)
  Move and refactor LoginRestServlet helper methods (#8182)

1 files changed, 4 insertions, 3 deletions

diff --git a/synapse/types.py b/synapse/types.py

index e867cadbad..ee169a3be8 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -18,7 +18,7 @@ import re
 import string
 import sys
 from collections import namedtuple
-from typing import Any, Dict, Tuple, Type, TypeVar
+from typing import Any, Dict, Mapping, MutableMapping, Tuple, Type, TypeVar
 
 import attr
 from signedjson.key import decode_verify_key_bytes
@@ -42,8 +42,9 @@ else:
 # Define a state map type from type/state_key to T (usually an event ID or
 # event)
 T = TypeVar("T")
-StateMap = Dict[Tuple[str, str], T]
-
+StateKey = Tuple[str, str]
+StateMap = Mapping[StateKey, T]
+MutableStateMap = MutableMapping[StateKey, T]
 
 # the type of a JSON-serialisable dict. This could be made stronger, but it will
 # do for now.