Re: What's cooking in git.git (Jul 2021, #03; Tue, 13)

From: Taylor Blau <me@ttaylorr.com>
Date: Jul 14, 2021, 20:11 UTC
Message-ID: <YO9FAwre6cj958D/@nand.local>
In-Reply-To: <xmqqmtqpzosf.fsf@gitster.g>

On Tue, Jul 13, 2021 at 06:07:12PM -0700, Junio C Hamano wrote:

Show 12 quoted lines

> * tb/midx-use-checksum (2021-06-28) 4 commits
>   (merged to 'next' on 2021-07-08 at bbaac9c721)
>  + midx: report checksum mismatches during 'verify'
>  + midx: don't reuse corrupt MIDXs when writing
>  + commit-graph: rewrite to use checksum_valid()
>  + csum-file: introduce checksum_valid()
>
>  When rebuilding the multi-pack index file reusing an existing one,
>  we used to blindly trust the existing file and ended up carrying
>  corrupted data into the updated file, which has been corrected.
>
>  Will merge to 'master'.

Thanks.

I had a moment of panic over my week off that the new code wasn't using the right hash for non-SHA-1 repositories. But we check that the hash version the file was written with matches 'the_hash_algo' at runtime, and we use 'the_hash_algo->rawsz' to determine the end of the contents, so we're all good here.

Show 8 quoted lines

> * tb/multi-pack-bitmaps (2021-06-28) 24 commits
> [...]
>
>  The reachability bitmap file used to be generated only for a single
>  pack, but now we've learned to generate bitmaps for history that
>  span across multiple packfiles.
>
>  Comments?

I would definitely appreciate some more comments, but I have only sporadically been keeping up-to-date with this series. Ævar sent some suggestions which I've been replying to today as I catch back up, but they appear mostly cosmetic (at least, the ones that I've read so far).

I think at this point I'd want a deep review from somebody familiar with bitmaps before re-rolling. Peff and I have both looked over the series exhaustively within GitHub, but the clean version submitted here should definitely be checked before merging.

I'm not in a big hurry to merge this, but there are some other good topics that are built on top (and it makes working on other bitmap related things kind of a pain since there are two choices for what to base it on).

Thanks, Taylor