This check is in the hot path, and can slow down writing when there are lots of small writes: https://github.com/twisted/twisted/blob/88172f74de390f148ec2a44829090718cdfd43c5/src/twisted/protocols/tls.py#L452 Fixing it will be done as followup to #11989
This check is in the hot path, and can slow down writing when there are lots of small writes:
twisted/src/twisted/protocols/tls.py
Line 452 in 88172f7
Fixing it will be done as followup to #11989