On 15 July 2014 14:13, Roberto Peon <grmocg@gmail.com> wrote: > Note that there the spec says to copy, but a smart implementation needs > not actually do that. It is an accounting trick. Yes I understand reference counting! As previously discussed, I'm not concerned about the actual copy of the strings of the header. I'm concerned that by copying a static entry into the header table you have to evict another entry. This makes inefficient use of the header table allowance as it can contain many (and duplicate) copies of static entries. The resulting churn in the header table will mean that all entries will need to be periodically resent. Note also that on an aggregate connection this copy can be used as part of a DoS, as a request could contain many and duplicated static indexes, which will cause the header table to be flushed and all shared connections to have to resend fields. It is also needless complexity for the encoder, which should just be able to know the index of :status:200 and drop that byte into the buffer. Instead it now has to do a lookup to see if and where the :status:200 field is in the dynamic table and use that index. I know it is not all that difficult to implement, but the only reason given for this copy was to limit the size of the reference set. If there is no reference set, then the copy has no purpose what so ever and it has some cost. We can't seriously be proposing to leave it in there as some kind of legacy kludge? regards -- Greg Wilkins <gregw@intalio.com> http://eclipse.org/jetty HTTP, SPDY, Websocket server and client that scales http://www.webtide.com advice and support for jetty and cometd.
Received on Tuesday, 15 July 2014 04:26:42 UTC