git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Jeff King <peff@peff.net>
To: Lars Schneider <larsxschneider@gmail.com>
Cc: "Junio C Hamano" <gitster@pobox.com>,
	"Torsten Bögershausen" <tboegi@web.de>,
	"Git Mailing List" <git@vger.kernel.org>,
	"Jakub Narębski" <jnareb@gmail.com>,
	mlbright@gmail.com, e@80x24.org
Subject: Re: [PATCH v4 11/12] convert: add filter.<driver>.process option
Date: Mon, 8 Aug 2016 11:02:55 -0400	[thread overview]
Message-ID: <20160808150255.2otm3z5fluimpiqw@sigill.intra.peff.net> (raw)
In-Reply-To: <A07BE78B-5A5D-41F1-A51B-5C71F3E86CCF@gmail.com>

On Sat, Aug 06, 2016 at 08:19:28PM +0200, Lars Schneider wrote:

> > I dunno. It's not _that_ big a deal to code around. I was just surprised
> > not to see an up-front status when responding to a request. It seems
> > like the normal thing in just about every protocol I've ever used.
> 
> Alright. The fact that it "surprised" you is a bad sign. 
> How about this:
> 
> Happy answer:
> ------------------------
> packet:          git< status=accept\n
> packet:          git< SMUDGED_CONTENT
> packet:          git< 0000
> packet:          git< status=success\n
> ------------------------

I notice that the status pkt-lines are by themselves. I had assumed we'd
be sending other data, too (presumably before, but I guess possibly
after, too). Something like:

  git< status=accept
  git< 0000
  git< SMUDGED_CONTENT
  git< 0000
  git< status=success
  git< 0000

I don't have any particular meta-information in mind, but I thought
stuff like the tentative "size" field would be here.

I had imagined it at the front, but I guess it could go in either place.
I wonder if keys at the end could simply replace ones from the beginning
(so if you say "foo=bar" at the front, that is tentative, but if you
then say "foo=revised" at the end, that takes precedence).

And so the happy answer is really:

  git< status=success
  git< 0000
  git< SMUDGED_CONTENT
  git< 0000
  git< 0000  # empty list!

i.e., no second status. The original "success" still holds.

And then:

> Happy answer with no content:
> ------------------------
> packet:          git< status=success\n
> ------------------------

This can just be spelled:

  git< status=success
  git< 0000
  git< 0000   # empty content!
  git< 0000   # empty list!

> Rejected content:
> ------------------------
> packet:          git< status=reject\n
> ------------------------

I'd assume that an error status would end the output for that file
immediately, no empty lists necessary (so what you have here). I'd
probably just call this "error" (see below).

> Error during content response:
> ------------------------
> packet:          git< status=accept\n
> packet:          git< HALF_WRITTEN_ERRONEOUS_CONTENT
> packet:          git< 0000
> packet:          git< status=error\n
> ------------------------

And then this would be:

  git< status=success
  git< 0000
  git< HALF_OF_CONTENT
  git< 0000
  git< status=error
  git< 0000

And then you have only two status codes: success and error. Which keeps
things simple.

There's one other case, which is when the filter dies halfway through
the conversation, like:

  git< status=success
  git< 0000
  git< CONTENT
  git< 0000
  ... EOF on pipe ...

Any time git does not get the conversation all the way to the final
flush after the trailers, it should be considered an error (because we
can never know if the filter was about to say "whoops, status=error").

-Peff

  reply	other threads:[~2016-08-08 15:03 UTC|newest]

Thread overview: 120+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20160727000605.49982-1-larsxschneider%40gmail.com/>
2016-07-29 23:37 ` [PATCH v3 00/10] Git filter protocol larsxschneider
2016-07-29 23:37   ` [PATCH v3 01/10] pkt-line: extract set_packet_header() larsxschneider
2016-07-30 10:30     ` Jakub Narębski
2016-08-01 11:33       ` Lars Schneider
2016-08-03 20:05         ` Jakub Narębski
2016-08-05 11:52           ` Lars Schneider
2016-07-29 23:37   ` [PATCH v3 02/10] pkt-line: add direct_packet_write() and direct_packet_write_data() larsxschneider
2016-07-30 10:49     ` Jakub Narębski
2016-08-01 12:00       ` Lars Schneider
2016-08-03 20:12         ` Jakub Narębski
2016-08-05 12:02           ` Lars Schneider
2016-07-29 23:37   ` [PATCH v3 03/10] pkt-line: add packet_flush_gentle() larsxschneider
2016-07-30 12:04     ` Jakub Narębski
2016-08-01 12:28       ` Lars Schneider
2016-07-31 20:36     ` Torstem Bögershausen
2016-07-31 21:45       ` Lars Schneider
2016-08-02 19:56         ` Torsten Bögershausen
2016-08-05  9:59           ` Lars Schneider
2016-07-29 23:37   ` [PATCH v3 04/10] pkt-line: call packet_trace() only if a packet is actually send larsxschneider
2016-07-30 12:29     ` Jakub Narębski
2016-08-01 12:18       ` Lars Schneider
2016-08-03 20:15         ` Jakub Narębski
2016-07-29 23:37   ` [PATCH v3 05/10] pack-protocol: fix maximum pkt-line size larsxschneider
2016-07-30 13:58     ` Jakub Narębski
2016-08-01 12:23       ` Lars Schneider
2016-07-29 23:37   ` [PATCH v3 06/10] run-command: add clean_on_exit_handler larsxschneider
2016-07-30  9:50     ` Johannes Sixt
2016-08-01 11:14       ` Lars Schneider
2016-08-02  5:53         ` Johannes Sixt
2016-08-02  7:41           ` Lars Schneider
2016-07-29 23:37   ` [PATCH v3 07/10] convert: quote filter names in error messages larsxschneider
2016-07-29 23:37   ` [PATCH v3 08/10] convert: modernize tests larsxschneider
2016-07-29 23:38   ` [PATCH v3 09/10] convert: generate large test files only once larsxschneider
2016-07-29 23:38   ` [PATCH v3 10/10] convert: add filter.<driver>.process option larsxschneider
2016-07-30 22:05     ` Jakub Narębski
2016-07-31  9:42       ` Jakub Narębski
2016-07-31 19:49         ` Lars Schneider
2016-07-31 22:59           ` Jakub Narębski
2016-08-01 13:32       ` Lars Schneider
2016-08-03 18:30         ` Designing the filter process protocol (was: Re: [PATCH v3 10/10] convert: add filter.<driver>.process option) Jakub Narębski
2016-08-05 10:32           ` Lars Schneider
2016-08-06 18:24           ` Lars Schneider
2016-08-03 22:47         ` [PATCH v3 10/10] convert: add filter.<driver>.process option Jakub Narębski
2016-07-31 22:19     ` Jakub Narębski
2016-08-01 17:55       ` Lars Schneider
2016-08-04  0:42         ` Jakub Narębski
2016-08-03 13:10       ` Lars Schneider
2016-08-04 10:18         ` Jakub Narębski
2016-08-05 13:20           ` Lars Schneider
2016-08-03 16:42   ` [PATCH v4 00/12] Git filter protocol larsxschneider
2016-08-03 16:42     ` [PATCH v4 01/12] pkt-line: extract set_packet_header() larsxschneider
2016-08-03 20:18       ` Junio C Hamano
2016-08-03 21:12         ` Jeff King
2016-08-03 21:27           ` Jeff King
2016-08-04 16:14           ` Junio C Hamano
2016-08-05 14:55             ` Lars Schneider
2016-08-05 16:31               ` Junio C Hamano
2016-08-05 17:31             ` Lars Schneider
2016-08-05 17:41               ` Junio C Hamano
2016-08-03 21:56         ` Lars Schneider
2016-08-03 16:42     ` [PATCH v4 02/12] pkt-line: add direct_packet_write() and direct_packet_write_data() larsxschneider
2016-08-03 16:42     ` [PATCH v4 03/12] pkt-line: add packet_flush_gentle() larsxschneider
2016-08-03 21:39       ` Jeff King
2016-08-03 22:56         ` [PATCH 0/7] minor trace fixes and cosmetic improvements Jeff King
2016-08-03 22:56           ` [PATCH 1/7] trace: handle NULL argument in trace_disable() Jeff King
2016-08-03 22:58           ` [PATCH 2/7] trace: stop using write_or_whine_pipe() Jeff King
2016-08-03 22:58           ` [PATCH 3/7] trace: use warning() for printing trace errors Jeff King
2016-08-04 20:41             ` Junio C Hamano
2016-08-04 21:21               ` Jeff King
2016-08-04 21:28                 ` Junio C Hamano
2016-08-05  7:56                   ` Jeff King
2016-08-05  7:59                   ` Christian Couder
2016-08-05 18:41                     ` Junio C Hamano
2016-08-03 23:00           ` [PATCH 4/7] trace: cosmetic fixes for error messages Jeff King
2016-08-04 20:42             ` Junio C Hamano
2016-08-05  8:00               ` Jeff King
2016-08-03 23:00           ` [PATCH 5/7] trace: correct variable name in write() error message Jeff King
2016-08-03 23:01           ` [PATCH 6/7] trace: disable key after write error Jeff King
2016-08-04 20:45             ` Junio C Hamano
2016-08-04 21:22               ` Jeff King
2016-08-05  7:58                 ` Jeff King
2016-08-03 23:01           ` [PATCH 7/7] write_or_die: drop write_or_whine_pipe() Jeff King
2016-08-03 23:04           ` [PATCH 0/7] minor trace fixes and cosmetic improvements Jeff King
2016-08-04 16:16         ` [PATCH v4 03/12] pkt-line: add packet_flush_gentle() Junio C Hamano
2016-08-03 16:42     ` [PATCH v4 04/12] pkt-line: call packet_trace() only if a packet is actually send larsxschneider
2016-08-03 16:42     ` [PATCH v4 05/12] pkt-line: add functions to read/write flush terminated packet streams larsxschneider
2016-08-03 16:42     ` [PATCH v4 06/12] pack-protocol: fix maximum pkt-line size larsxschneider
2016-08-03 16:42     ` [PATCH v4 07/12] run-command: add clean_on_exit_handler larsxschneider
2016-08-03 21:24       ` Jeff King
2016-08-03 22:15         ` Lars Schneider
2016-08-03 22:53           ` Jeff King
2016-08-03 23:09             ` Lars Schneider
2016-08-03 23:15               ` Jeff King
2016-08-05 13:08                 ` Lars Schneider
2016-08-05 21:19                   ` Torsten Bögershausen
2016-08-05 21:50                     ` Lars Schneider
2016-08-03 16:42     ` [PATCH v4 08/12] convert: quote filter names in error messages larsxschneider
2016-08-03 16:42     ` [PATCH v4 09/12] convert: modernize tests larsxschneider
2016-08-03 16:42     ` [PATCH v4 10/12] convert: generate large test files only once larsxschneider
2016-08-03 16:42     ` [PATCH v4 11/12] convert: add filter.<driver>.process option larsxschneider
2016-08-03 17:45       ` Junio C Hamano
2016-08-03 21:48         ` Lars Schneider
2016-08-03 22:46           ` Jeff King
2016-08-05 12:53             ` Lars Schneider
2016-08-03 20:29       ` Junio C Hamano
2016-08-03 21:37         ` Lars Schneider
2016-08-03 21:43           ` Junio C Hamano
2016-08-03 22:01             ` Lars Schneider
2016-08-05 21:34       ` Torsten Bögershausen
2016-08-05 21:49         ` Lars Schneider
2016-08-05 22:06         ` Junio C Hamano
2016-08-05 22:27           ` Jeff King
2016-08-06 11:55             ` Lars Schneider
2016-08-06 12:14               ` Jeff King
2016-08-06 18:19                 ` Lars Schneider
2016-08-08 15:02                   ` Jeff King [this message]
2016-08-08 16:21                     ` Lars Schneider
2016-08-08 16:26                       ` Jeff King
2016-08-06 20:40           ` Torsten Bögershausen
2016-08-03 16:42     ` [PATCH v4 12/12] convert: add filter.<driver>.process shutdown command option larsxschneider

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160808150255.2otm3z5fluimpiqw@sigill.intra.peff.net \
    --to=peff@peff.net \
    --cc=e@80x24.org \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=jnareb@gmail.com \
    --cc=larsxschneider@gmail.com \
    --cc=mlbright@gmail.com \
    --cc=tboegi@web.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).