Re: [PATCH v3 00/16] midx: implement a multi-pack reverse index

[Jeff King <peff@peff.net>]

On Thu, Mar 11, 2021 at 12:04:31PM -0500, Taylor Blau wrote:

> Here is another reroll of my series to implement a reverse index in
> preparation for multi-pack reachability bitmaps. The previous version
> was based on 'ds/chunked-file-api', but that topic has since been merged
> to 'master'. This series is now built directly on top of 'master'.

I gave the whole thing another careful read. Most of what I found were
small nits, but enough that I think one more re-roll is worth it.

The biggest question is what we want to happen next. As you note, the
concept of a midx .rev file is useless until we have the matching
.bitmap file. So we _could_ let this sit in next while the dependent
bitmap topic is reviewed, and then merge them down together. But I'm
inclined to treat this as an independent topic that can get merged to
master on its own, since the early cleanups are valuable on their own,
and the .rev parts at the end, even if dead, won't hurt anything.

If we did want to break it up, the useful line would be after "allow
marking a pack as preferred" (while it is mostly intended for the bitmap
selection, it is theoretically useful on its own to make it more likely
to find a copy of an object with a useful delta).

-Peff