Just a comment: RFC 7540 says below in [5.3.4. Prioritization State Management](https://tools.ietf.org/html/rfc7540#section-5.3.4). So circular buffer make sense.
> To avoid these problems, an endpoint SHOULD retain stream prioritization state for a period after streams become closed. [ Full content available at: https://github.com/apache/trafficserver/pull/4212 ] This message was relayed via gitbox.apache.org for [email protected]
