diff --git a/synapse/rest/client/transactions.py b/synapse/rest/client/transactions.py
index f2aaab6227..0d8a63d8be 100644
--- a/synapse/rest/client/transactions.py
+++ b/synapse/rest/client/transactions.py
@@ -50,6 +50,8 @@ class HttpTransactionCache:
# for at *LEAST* 30 mins, and at *MOST* 60 mins.
self.cleaner = self.clock.looping_call(self._cleanup, CLEANUP_PERIOD_MS)
+ self._msc3970_enabled = hs.config.experimental.msc3970_enabled
+
def _get_transaction_key(self, request: IRequest, requester: Requester) -> Hashable:
"""A helper function which returns a transaction key that can be used
with TransactionCache for idempotent requests.
@@ -58,6 +60,7 @@ class HttpTransactionCache:
requests to the same endpoint. The key is formed from the HTTP request
path and attributes from the requester: the access_token_id for regular users,
the user ID for guest users, and the appservice ID for appservice users.
+ With MSC3970, for regular users, the key is based on the user ID and device ID.
Args:
request: The incoming request.
@@ -67,11 +70,21 @@ class HttpTransactionCache:
"""
assert request.path is not None
path: str = request.path.decode("utf8")
+
if requester.is_guest:
assert requester.user is not None, "Guest requester must have a user ID set"
return (path, "guest", requester.user)
+
elif requester.app_service is not None:
return (path, "appservice", requester.app_service.id)
+
+ # With MSC3970, we use the user ID and device ID as the transaction key
+ elif self._msc3970_enabled:
+ assert requester.user, "Requester must have a user"
+ assert requester.device_id, "Requester must have a device_id"
+ return (path, "user", requester.user, requester.device_id)
+
+ # Otherwise, the pre-MSC3970 behaviour is to use the access token ID
else:
assert (
requester.access_token_id is not None
|
