git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / Atom feed
From: Lars Schneider <larsxschneider@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Eric Wong <e@80x24.org>, git@vger.kernel.org
Subject: Re: RFC: Enable delayed responses to Git clean/smudge filter requests
Date: Thu, 24 Nov 2016 16:45:45 +0100
Message-ID: <249EE7A4-F297-4537-92A9-0EF75A3B1AEE@gmail.com> (raw)
In-Reply-To: <xmqqvavotych.fsf@gitster.mtv.corp.google.com>


> On 15 Nov 2016, at 19:03, Junio C Hamano <gitster@pobox.com> wrote:
> 
> Lars Schneider <larsxschneider@gmail.com> writes:
> 
>>> The filter itself would need to be aware of parallelism
>>> if it lives for multiple objects, right?
>> 
>> Correct. This way Git doesn't need to deal with threading...
> 
> I think you need to be careful about three things (at least; there
> may be more):
> 
> ...
> 
> * Done naively, it will lead to unmaintainable code, like this:
> 
>  ...

Hi Junio,

I started to work on the "delayed responses to Git clean/smudge filter
requests" implementation and I am looking for a recommendation regarding 
code maintainability:

Deep down in convert.c:636 `apply_multi_file_filter()` [1] the filter learns
from the external process that the filter response is not yet available.
I need to transport this information quite a few levels up the call
stack. 


# Option 1
I could do this by explicitly passing a pointer such as "int *is_delayed" 
to the function. This would mean I need to update the function definitions 
for all functions on my way through the stack:

int apply_multi_file_filter()
int apply_filter()
int convert_to_working_tree_internal()
int convert_to_working_tree()
...

# Option 2
All these functions pass-through an "int" return value that communicates
if the filter succeeded or failed. I could define a special return value
to communicate the third state: delayed. 


What way do you think is better from a maintenance point of view?
I prefer option 2 but I fear that these "special" values could confuse
future readers of the code.

Thanks,
Lars


[1] https://github.com/git/git/blob/e2b2d6a172b76d44cb7b1ddb12ea5bfac9613a44/convert.c#L673-L777


  parent reply	other threads:[~2016-11-24 16:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-14 21:09 Lars Schneider
2016-11-15  1:03 ` Eric Wong
2016-11-15 14:29   ` Lars Schneider
2016-11-15 18:03     ` Junio C Hamano
2016-11-16  9:53       ` Lars Schneider
2016-11-16 18:15         ` Junio C Hamano
2016-11-16 18:47           ` Lars Schneider
2016-11-16 19:19             ` Junio C Hamano
2016-11-16 22:41         ` Jakub Narębski
2016-11-16 23:46           ` Junio C Hamano
2016-11-17  9:19             ` Lars Schneider
2016-11-24 15:45       ` Lars Schneider [this message]
2016-11-28 21:48         ` Junio C Hamano
2016-11-15 18:27     ` Eric Wong
2017-01-09 20:44 ` Stefan Beller
2017-01-11 12:57   ` Lars Schneider

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=249EE7A4-F297-4537-92A9-0EF75A3B1AEE@gmail.com \
    --to=larsxschneider@gmail.com \
    --cc=e@80x24.org \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    /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

git@vger.kernel.org list mirror (unofficial, one of many)

This inbox may be cloned and mirrored by anyone:

	git clone --mirror http://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 git git/ http://public-inbox.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git
	nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for the project(s) associated with this inbox:

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

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git