Re: [PATCH 00/21] Maintenance builtin, allowing 'gc --auto' customization

Derrick Stolee [off-list ref] writes:

It is important to recognize that there are already several "tasks" that
run inside 'gc' including:

1. Expiring reflogs.
2. Repacking all reachable objects.
3. Deleting unreachable objects.
4. Packing refs.

Before trying to "remove" the gc builtin, we would want these to be
represented in the 'git maintenance run' as tasks.

Yup.  I like the overall direction of this approach to (1) have a
single subcommand that helps all the housekeeping tasks, and to (2)
make sure existing housekeeping tasks are supported by the new one.

I can understand why it is tempting to start with a new 'main()'
under a new subcommand name because we expect to add a lot more
tasks, but the name of that subcommand is much less important.

As can be seen in the list you have above, "gc" already does a lot
more than garbage collection (just #3 is the "garbage collection"
proper), as it has grown by following the same approach.

What's more important is (2) above.  While the tool has grown under
the same "gc" name, it was easier to arrange---it fell out naturally
as a consequence of the development being an enhancement on top of
the prior work.  Now that we are reimplementing, we need to actively
care.  As long as we recognize that, I am perfectly happy with the
current effort.

For existing callers, "git gc --auto" may want to be left alive,
merely as a thin wrapper around "git maintenance --auto", and as
long as the latter is done in the same spirit of the former, i.e.
perform a lightweight check to see if the repository is so out of
shape and then do a minimum cleaning, it would be welcomed by users
if it does a lot more than the current "git gc --auto".

Thanks.

On 7/9/2020 10:05 AM, Junio C Hamano wrote:

For existing callers, "git gc --auto" may want to be left alive,
merely as a thin wrapper around "git maintenance --auto", and as
long as the latter is done in the same spirit of the former, i.e.
perform a lightweight check to see if the repository is so out of
shape and then do a minimum cleaning, it would be welcomed by users
if it does a lot more than the current "git gc --auto".

It's entirely possible that (after the 'maintenance' builtin
stabilizes) that we make 'git gc --auto' become an alias of something
like 'git maintenance run --task=gc --auto' (or itemize all of the
sub-tasks) so that 'git gc --auto' doesn't change behavior.

That's a big motivation for adding all code into builtin/gc.c so
we can access these tasks inside GC without needing to move or
copy the code. I'm trying to preserve history as much as possible.

Thanks,
-Stolee