Re: [PATCH v6 07/14] commit-graph: implement 'git-commit-graph write'

[Derrick Stolee <stolee@gmail.com>]

On 3/19/2018 10:36 AM, Ævar Arnfjörð Bjarmason wrote:
> On Mon, Mar 19 2018, Derrick Stolee jotted:
>
>> On 3/18/2018 9:25 AM, Ævar Arnfjörð Bjarmason wrote:
>>> On Wed, Mar 14 2018, Derrick Stolee jotted:
>>>
>>>> +'git commit-graph write' <options> [--object-dir <dir>]
>>>> +
>>>> +
>>>> +DESCRIPTION
>>>> +-----------
>>>> +
>>>> +Manage the serialized commit graph file.
>>>> +
>>>> +
>>>> +OPTIONS
>>>> +-------
>>>> +--object-dir::
>>>> +	Use given directory for the location of packfiles and commit graph
>>>> +	file. The commit graph file is expected to be at <dir>/info/commit-graph
>>>> +	and the packfiles are expected to be in <dir>/pack.
>>> Maybe this was covered in a previous round, this series is a little hard
>>> to follow since each version isn't In-Reply-To the version before it,
>>> but why is this option needed, i.e. why would you do:
>>>
>>>       git commit-graph write --object-dir=/some/path/.git/objects
>>>
>>> As opposed to just pigging-backing on what we already have with both of:
>>>
>>>       git --git-dir=/some/path/.git commit-graph write
>>>       git -C /some/path commit-graph write
>>>
>>> Is there some use-case where you have *just* the objects dir and not the
>>> rest of the .git folder?
>> Yes, such as an alternate. If I remember correctly, alternates only
>> need the objects directory.
>>
>> In the GVFS case, we place prefetch packfiles in an alternate so there
>> is only one copy of the "remote objects" per drive. The commit graph
>> will be stored in that alternate.
> Makes sense, but we should really document this as being such an unusual
> option, i.e. instead say something like.
>
>      Use given directory for the location of packfiles and commit graph
>      file. Usually you'd use the `--git-dir` or `-C` arguments to `git`
>      itself. This option is here to support obscure use-cases where we
>      have a stand-alone object directory. The commit graph file is
>      expected to be at <dir>/info/commit-graph and the packfiles are
>      expected to be in <dir>/pack.

A slight change to your recommendation:


OPTIONS
-------
--object-dir::
         Use given directory for the location of packfiles and commit graph
         file. This parameter exists to specify the location of an alternate
         that only has the objects directory, not a full .git directory. The
         commit graph file is expected to be at <dir>/info/commit-graph and
         the packfiles are expected to be in <dir>/pack.