Re: [PATCH 2/2] rev-list: add --disk-usage option for calculating disk usage

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Jan 27, 2021, 23:07 UTC
Message-ID: <CAPig+cQTV6ACiOj+GKoBwj15TZBr5craVPT6dYzzSDfrX9a3YA@mail.gmail.com>
In-Reply-To: <YBHmY7vNxu2hqOa/@coredump.intra.peff.net>

On Wed, Jan 27, 2021 at 5:20 PM Jeff King <peff@peff.net> wrote:

Show 13 quoted lines

> This patch implements a --disk-usage option which produces the same
> answer in a fraction of the time. Here are some timings using a clone of
> torvalds/linux:
>
>   [rev-list piped to cat-file, no bitmaps]
>   $ time git rev-list --objects --all |
>     cut -d' ' -f1 |
>     git cat-file --buffer --batch-check='%(objectsize:disk)' |
>     perl -lne '$total += $_; END { print $total }'
>   1455691059
>   real  0m34.336s
>   user  0m46.533s
>   sys   0m2.953s

This example shows the computed size (1455691059)...

Show 10 quoted lines

> But the real win is with bitmaps. If we use them without the new option:
>
>   [rev-list piped to cat-file, bitmaps]
>   $ time git rev-list --objects --all --use-bitmap-index |
>     cut -d' ' -f1 |
>     git cat-file --batch-check='%(objectsize:disk)' |
>     perl -lne '$total += $_; END { print $total }'
>   real  0m9.954s
>   user  0m11.234s
>   sys   0m8.522s

...however, this example does not (but all the others do). Simple copy/paste error?

Not worth a re-roll, of course.