- From: William A. Rowe, Jr. <wrowe@rowe-clan.net>
- Date: Mon, 20 Oct 2008 19:36:49 -0500
- To: Jamie Lokier <jamie@shareable.org>
- CC: Henrik Nordstrom <henrik@henriknordstrom.net>, Greg Dean <dean.greg@gmail.com>, ietf-http-wg@w3.org
Jamie Lokier wrote: > Henrik Nordstrom wrote: >> On mån, 2008-10-20 at 13:52 -0700, Greg Dean wrote: >>> Transfer-Encoding: chunked >>> Estimated-Content-Length: 300000 >>> This would allow for the recipient of such a message to prepare for a >>> message of a certain size. >> Looks useful to me, for the reasons you outlined and a bunch more. See >> for example the NTLM auth chunked discussion a year ago or so.. >> >> For responses it's meaningful even without chunked. >> >> I don't see anything wrong with it, especially not with the length being >> an estiamte and not the exact expected lenght. > > In some circumstances you may be able to refine the estimate as the > message is being transmitted. > > Chunk extensions ("chunk-extension") would suit that: > > 1000;estimated-remaining=299000 > (1000 bytes) > 1000;estimated-remaining=298000 > (1000 bytes) > > I don't know if chunk extensions break in the real world, though. Or, permit 1000;completed=25% (1000 bytes) 1000;completed=25% (1000 bytes) My only concern about implementing an 'estimated' extension is what is your pain tolerance in terms of deviation? Would a min or max be a better fit to the problem set? Given that precomputing the result size is often suboptimal for todays' assembled responses, but there is a desire to have something to share with the user, the % notation might work well. I'm concerned that the estimate will become an expectation, also costly to precompute, but rarely useful in practice.
Received on Tuesday, 21 October 2008 00:37:38 UTC