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From: Junio C Hamano <gitster@pobox•com>
To: Augie Fackler <augie@google•com>
Cc: Jeff King <peff@peff•net>, Johannes Sixt <j6t@kdbg•org>,
	git@vger•kernel.org, Stefan Beller <sbeller@google•com>
Subject: Re: [PATCH 3/3] pkt-line: support tracing verbatim pack contents
Date: Tue, 16 Jun 2015 09:39:19 -0700	[thread overview]
Message-ID: <xmqqvben6214.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <CAHcr6HYvVR4uTmtegWHK0h+v_aVs4JVLsSwvjthGY3pb=-Q0yQ@mail.gmail.com> (Augie Fackler's message of "Tue, 16 Jun 2015 11:38:41 -0400")

Augie Fackler <augie@google•com> writes:

> On Fri, Jun 12, 2015 at 5:28 PM, Jeff King <peff@peff•net> wrote:
>> When debugging the pack protocol, it is sometimes useful to
>> store the verbatim pack that we sent or received on the
>> wire. Looking at the on-disk result is often not helpful for
>> a few reasons:
>>
>>   1. If the operation is a clone, we destroy the repo on
>>      failure, leaving nothing on disk.
>>
>>   2. If the pack is small, we unpack it immediately, and the
>>      full pack never hits the disk.
>>
>>   3. If we feed the pack to "index-pack --fix-thin", the
>>      resulting pack has the extra delta bases added to it.
>>
>> We already have a GIT_TRACE_PACKET mechanism for tracing
>> packets. Let's extend it with GIT_TRACE_PACK to dump the
>> verbatim packfile.
>
> FWIW, this also works for me - I have no preference between my patches
> and Jeff's. I suspect yours are much better given that you have a clue
> about git internals ;).
>
> One bit of feedback is that it might be worth mentioning (though I
> don't feel strongly) that GIT_TRACE_PACK works with or without
> GIT_TRACE_PACKET - that wasn't immediately obvious to me, but it makes
> sense once I read the code.
>
> Thanks!

Thanks, both.  I think this series makes sense.

As to the documentation, I have a feeling that, unless the reader
and/or the user intimately knows that TRACE_PACK is implemented by
hooking into the same mechanism that TRACE_PACKET needs to, s/he
would not even wonder if TRACE_PACKET needs to be enabled when
asking for TRACE_PACK.  Yes, one is a proper substring of the other,
but the similarity between the two stops there.  While I do not
think it would hurt very much to mention that they are independent,
I have a slight suspicion that it might make it more likely to get
user confused.

  reply	other threads:[~2015-06-16 16:39 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAGZ79kaS4utvDbXOo7emmSUH6M-8LY-oA65Ss3PLDkFModkbSg@mail.gmail.com>
2015-06-11 18:59 ` [PATCH v2] fetch-pack: optionally save packs to disk Augie Fackler
2015-06-12  6:22   ` Johannes Sixt
2015-06-12 15:07     ` Junio C Hamano
2015-06-12 17:02       ` Augie Fackler
2015-06-12 18:00       ` Jeff King
2015-06-12 21:25         ` Jeff King
2015-06-12 21:28           ` [PATCH 1/3] pkt-line: simplify starts_with checks in packet tracing Jeff King
2015-06-12 21:35             ` Stefan Beller
2015-06-12 21:28           ` [PATCH 2/3] pkt-line: tighten sideband PACK check when tracing Jeff King
2015-06-12 21:39             ` Stefan Beller
2015-06-12 21:41               ` Jeff King
2015-06-12 21:43                 ` Stefan Beller
2015-06-12 21:28           ` [PATCH 3/3] pkt-line: support tracing verbatim pack contents Jeff King
2015-06-16 15:38             ` Augie Fackler
2015-06-16 16:39               ` Junio C Hamano [this message]
2015-06-16 16:43                 ` Jeff King
2015-06-16 16:52                   ` Augie Fackler
2015-06-16 17:23                     ` Jeff King
2015-06-16 17:10               ` Jeff King
2015-06-16 17:14                 ` Augie Fackler
2015-06-16 17:18                   ` Jeff King
2015-06-16 17:23                     ` Augie Fackler
2015-06-16 19:31                       ` [PATCH/RFC 0/3] add GIT_TRACE_STDIN Jeff King
2015-06-16 19:35                         ` [PATCH 1/3] trace: implement %p placeholder for filenames Jeff King
2015-06-16 19:36                         ` [PATCH 2/3] trace: add pid to each output line Jeff King
2015-06-16 19:37                         ` [PATCH 3/3] trace: add GIT_TRACE_STDIN Jeff King
2015-06-16 19:49                           ` Jeff King
2015-06-16 21:20                             ` Jeff King
2015-06-17 10:04                               ` Duy Nguyen
2015-06-17 19:10                                 ` Jeff King
2015-06-18 10:20                                   ` Duy Nguyen
2015-06-26 18:47                                   ` Junio C Hamano
2015-06-12 16:54     ` [PATCH v2] fetch-pack: optionally save packs to disk Augie Fackler

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