Re: [PATCH v2 0/6] reuse on-disk deltas for fetches with bitmaps

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Fri, Aug 17, 2018 at 04:54:27PM -0400, Jeff King wrote:
>
>> This series more aggressively reuses on-disk deltas to serve fetches
>> when reachability bitmaps tell us a more complete picture of what the
>> client has. That saves server CPU and results in smaller packs. See the
>> final patch for numbers and more discussion.
>
> Here's a v2, with just a few cosmetic fixes to address the comments on
> v1 (range-diff below).
>
>   [1/6]: t/perf: factor boilerplate out of test_perf
>   [2/6]: t/perf: factor out percent calculations
>   [3/6]: t/perf: add infrastructure for measuring sizes
>   [4/6]: t/perf: add perf tests for fetches from a bitmapped server
>   [5/6]: pack-bitmap: save "have" bitmap from walk
>   [6/6]: pack-objects: reuse on-disk deltas for thin "have" objects

Thanks.

> 1:  89fa0ec8d8 ! 1:  3e1b94d7d6 pack-bitmap: save "have" bitmap from walk
>     @@ -69,6 +69,8 @@
>      +
>      +	if (!bitmap_git)
>      +		return 0; /* no bitmap loaded */
>     ++	if (!bitmap_git->result)
>     ++		BUG("failed to perform bitmap walk before querying");
>      +	if (!bitmap_git->haves)
>      +		return 0; /* walk had no "haves" */
>      +

The first four are unchanged, so this actually compares 5/6 of the
previous and the current one.  Omitting the four identical ones
makes sense, but I wonder if it makes it easier to see if we keep
the number-label of the surviving patches.

> 2:  f7ca0d59e3 ! 2:  b8b2416aac pack-objects: reuse on-disk deltas for thin "have" objects