Re: [PATCH 01/11] config-batch: basic boilerplate of new builtin

From: Derrick Stolee <stolee@gmail.com>
Date: Feb 5, 2026, 14:17 UTC
Message-ID: <6c8b984e-feda-48c6-b67d-80a41343bfc0@gmail.com>
In-Reply-To: <xmqq1pj0nleg.fsf@gitster.g>

On 2/4/2026 6:23 PM, Junio C Hamano wrote:

Show 18 quoted lines

> "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> From: Derrick Stolee <stolee@gmail.com>
>>
>> Later changes will document, implement, and test this new builtin. For now,
>> this serves as the latest example of the minimum boilerplate to introduce a
>> new builtin.
>>
>> Recently, we updated the comment in builtin.h about how to create a new
>> builtin, but failed to mention the required change to meson.build files for
>> some CI builds to pass. Fix that oversight.
>>
>> Signed-off-by: Derrick Stolee <stolee@gmail.com>
>> ---
> 
> We have had a bad reputation for having too many commands; would it
> be better to present it as a new mode of existing "git config"
> command at the end-user level, I wonder?

Interesting thought. I think we also have a bad reputation of commands that are overloaded with too many purposes.

In this case, though, I do think that the modern 'git config <subcommand>' model presents some clear boundaries for how the command should behave with the 'batch' (or 'server') subcommand. Grouping all config-related operations in the same builtin may be ideal.

> Also after reading patches for a few early steps, I do not quite see
> "batch"-ness in this protocol; it is strictly "a single request is
> met with a single response".

The batch-ness is that multiple requests can eventually go to the same process. The client could collect multiple commands in a batch and send them all without processing the responses one-by-one. This is how it works in the tests: a single input file is prepared and all responses are scanned after-the-fact.

The back-and-forth mechanism is how the git-credential-manager tool would use it, because it dynamically explores certain config keys. For example: it checks the deepest possible URL for a specific key then peels away the last segment of the URL to see if there is a directory-prefix match in a key. (This is the main reason that there are so many requests in this application.)

I believe this is similar to how 'git cat-file --batch' or 'git cat-file --batch-check' work, which was my inspiration for this word. If we regret those names, then I'm happy to move towards a better name.

Thanks, -Stolee