Re: [PATCH] upload-pack: squelch progress indicator if client does not request sideband

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 16, 2009, 05:02 UTC
Message-ID: <7vprd4hito.fsf@alter.siamese.dyndns.org>
In-Reply-To: <alpine.LFD.2.00.0906152109240.16467@xanadu.home>

Nicolas Pitre <nico@cam.org> writes:

Show 13 quoted lines

>>      How did we drive upload-pack over native or ssh connection before we
>>      introduced sideband?  I vaguely recall that we relied on stderr going
>>      to the invoking terminal in the local case.  With this change, does
>>      the user suddenly stop seeing progress if the client is older than
>>      583b7ea (upload-pack/fetch-pack: support side-band communication,
>>      2006-06-21)?  If so, that would be a regression.
>
> Native, or git:// style, certainly never was able to get any kind of 
> progress display without sideband support.
>
> As to old clients using ssh... well... that could be a regression.  But 
> do we really care?  This is pre v1.4.1 after all, and even the previous 
> Debian stable was using a later git version.

I guess both ssh and local would regress, and we do care about regressions in general, but I think it is not a grave offense in this case, because the combination between such an old fetch and the updated upload-pack will still transfer the objects and will update the refs as expected; only the progress indication and chatter on the stderr stream will be lost.

So I would say it is Ok to regress in this particular case, _if_ there is no easy way to avoid it. That was why I asked:

Show 7 quoted lines

>> I think it is a very good idea to squelch progress output that will never
>> go to the client (it will be wasted traffic, regardless of the "syslog"
>> thing), but
>> 
>>  (1) Is "not using sideband" the same as "client won't see the progress
>>      output" for all vintages of clients that work with the current
>>      server?

Stated differently, I think "not using sideband _and_ spawned via daemon" would be an indication that "the client won't see the progress anyway even if it were sent." So the question becomes "will it be a small enough change to detect if the upload-pack is driven by the daemon in the codepath J6t added 'if (!use_sideband)' to, and if so shouldn't we do so?"