Reduce unnecessary whitespace in JSON. (#7372)

synapse/util/__init__.py

@@ -17,6 +17,7 @@ import logging
 import re
 
 import attr
+from canonicaljson import json
 
 from twisted.internet import defer, task
 
@@ -24,6 +25,9 @@ from synapse.logging import context
 
 logger = logging.getLogger(__name__)
 
+# Create a custom encoder to reduce the whitespace produced by JSON encoding.
+json_encoder = json.JSONEncoder(separators=(",", ":"))
+
 
 def unwrapFirstError(failure):
     # defer.gatherResults and DeferredLists wrap failures.