INNER CODE UNIT · Python
_merge_headers
redis/fastapi-redis-sdk · src/redis_fastapi/cache.py:348
def _merge_headers(
base: list[tuple[bytes, bytes]],
overrides: list[tuple[bytes, bytes]],
) -> list[tuple[bytes, bytes]]:
"""Return *base* with every field named in *overrides* replaced, not joined.
The fields this middleware sets are single-valued. RFC 9110 section 8.8.3
defines ``ETag = entity-tag`` - one tag, not a list - so appending ours
beside a validator the endpoint already set would emit a field no client
can parse, and a conditional request echoing it would never match.
``Cache-Control`` appended the same way yields two ``max-age`` directives.
Args:
base: Raw ASGI headers as the endpoint produced them.
overrides: Headers this middleware owns; each replaces every earlier
occurrence of the same name.
Returns: