Allow bigger responses to `/federation/v1/state` (#12877)

* Refactor HTTP response size limits

Rather than passing a separate `max_response_size` down the stack, make it an
attribute of the `parser`.

* Allow bigger responses on `federation/v1/state`

`/state` can return huge responses, so we need to handle that.

1 files changed, 8 insertions, 7 deletions

diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 9ce06dfa28..25df1905c6 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -49,11 +49,6 @@ from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
-# Send join responses can be huge, so we set a separate limit here. The response
-# is parsed in a streaming manner, which helps alleviate the issue of memory
-# usage a bit.
-MAX_RESPONSE_SIZE_SEND_JOIN = 500 * 1024 * 1024
-
 
 class TransportLayerClient:
     """Sends federation HTTP requests to other servers"""
@@ -349,7 +344,6 @@ class TransportLayerClient:
             path=path,
             data=content,
             parser=SendJoinParser(room_version, v1_api=True),
-            max_response_size=MAX_RESPONSE_SIZE_SEND_JOIN,
         )
 
     async def send_join_v2(
@@ -372,7 +366,6 @@ class TransportLayerClient:
             args=query_params,
             data=content,
             parser=SendJoinParser(room_version, v1_api=False),
-            max_response_size=MAX_RESPONSE_SIZE_SEND_JOIN,
         )
 
     async def send_leave_v1(
@@ -1360,6 +1353,11 @@ class SendJoinParser(ByteParser[SendJoinResponse]):
 
     CONTENT_TYPE = "application/json"
 
+    # /send_join responses can be huge, so we override the size limit here. The response
+    # is parsed in a streaming manner, which helps alleviate the issue of memory
+    # usage a bit.
+    MAX_RESPONSE_SIZE = 500 * 1024 * 1024
+
     def __init__(self, room_version: RoomVersion, v1_api: bool):
         self._response = SendJoinResponse([], [], event_dict={})
         self._room_version = room_version
@@ -1427,6 +1425,9 @@ class _StateParser(ByteParser[StateRequestResponse]):
 
     CONTENT_TYPE = "application/json"
 
+    # As with /send_join, /state responses can be huge.
+    MAX_RESPONSE_SIZE = 500 * 1024 * 1024
+
     def __init__(self, room_version: RoomVersion):
         self._response = StateRequestResponse([], [])
         self._room_version = room_version