From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: "Robert P. J. Day" <rpjday@crashcourse•ca>,
Stephan Janssen <sjanssen@you-get•com>,
"git\@vger.kernel.org" <git@vger•kernel.org>
Subject: Re: [PATCH 3/4] clone: factor out dir_exists() helper
Date: Fri, 05 Jan 2018 11:19:19 -0800 [thread overview]
Message-ID: <xmqqo9m8cdvs.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20180105002206.GB3474@sigill.intra.peff.net> (Jeff King's message of "Thu, 4 Jan 2018 19:22:06 -0500")
Jeff King <peff@peff•net> writes:
> On Thu, Jan 04, 2018 at 06:54:12PM -0500, Jeff King wrote:
>
>> > If we really want to be anal, perhaps a new helper path_exists()
>> > that cares only about existence of paths (i.e. the implementation of
>> > these two helpers they currently have), together with update to
>> > check the st.st_mode for file_exists() and dir_exists(), may help
>> > making the API set more rational, but I do not think it is worth it.
>>
>> Yep, I also considered that file_exists() probably wants to be
>> path_exists() with its current implementation. We'd probably want to
>> review all of the callers.
>>
>> Anyway, I tried to do the minimal refactoring here, with no change in
>> behavior. I'm not opposed to calling this dir_exists() as path_exists()
>> and making it globally available (as you note, I don't think we'd want
>> to use a true dir_exists() here).
>
> So I actually started down this road just now, but I'm not sure if it's
> worth it.
Yeah, although I said it already without starting down this road,
you actually thought about it more and your insight is more valuable
;-)
> If we were to transition to an endgame with path_exists(),
> dir_exists(), and file_exists(), we'd probably want to do something
> like:
>
> 1. introduce path_exists(), but leave existing file_exists() callers
> in place
>
> 2. introduce file_exists_as_file(), which checks S_IFREG
>
> 3. audit each file_exists() call to see if it ought to be
> path_exists() or file_exists_as_file() and convert as needed
>
> 4. When there are no more file_exists() calls left, all
> file_exists_as_file() instances can be renamed to file_exists().
>
> But as with any "audit each..." plan, that leaves topics in flight out
> of luck. If we want to be kind to those, we'd have to wait a long while
> to shake out any file_exists() callers.
>
> At which point is there much value in having path_exists() as a wrapper?
> It's a better name, perhaps, but I think my future-proofing against
> "file_exists() may become file-specific" was probably overly paranoid. I
> don't think we could sanely do that conversion without risking breakage.
If we want to, the endgame can be to have a single path_exists_as()
helper that could be used like so:
#define PATH_TYPE_IFREG (1<<0)
#define PATH_TYPE_IFLNK (1<<1)
#define PATH_TYPE_IFDIR (1<<2)
#define PATY_TYPE_IFANY ((1<<3)-1)
#define path_exists(path) path_exists_as(path, PATH_TYPE_ANY)
#define path_exists_as_file(path) path_exists_as(path, PATH_TYPE_IFREG)
/* backward compatibility */
#define file_exists(path) path_exists_as(path, PATH_TYPE_ANY)
We can avoid "file-exists used to mean this thing but in a distant
future it means completely different thing" that way.
> Maybe we should just document its behavior and use it here, rather than
> introducing this new dir_exists().
Sounds good enough to me ;-)
next prev parent reply other threads:[~2018-01-05 19:19 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-02 11:10 Git removes existing folder when cancelling clone Stephan Janssen
2018-01-02 11:12 ` Robert P. J. Day
2018-01-02 20:04 ` Jeff King
2018-01-02 21:07 ` [PATCH 0/4] " Jeff King
2018-01-02 21:08 ` [PATCH 1/4] t5600: fix outdated comment about unborn HEAD Jeff King
2018-01-02 21:09 ` [PATCH 2/4] t5600: modernize style Jeff King
2018-01-02 21:10 ` [PATCH 3/4] clone: factor out dir_exists() helper Jeff King
2018-01-04 23:47 ` Junio C Hamano
2018-01-04 23:54 ` Jeff King
2018-01-05 0:22 ` Jeff King
2018-01-05 19:19 ` Junio C Hamano [this message]
2018-01-02 21:11 ` [PATCH 4/4] clone: do not clean up directories we didn't create Jeff King
2018-01-02 22:49 ` Eric Sunshine
2018-01-02 23:39 ` Jeff King
2018-01-05 18:50 ` Junio C Hamano
2018-01-04 23:48 ` Junio C Hamano
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