git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: git@vger.kernel.org
Subject: Re: [PATCH 3/4] cat-file: add --batch-disk-sizes option
Date: Sun, 07 Jul 2013 10:49:46 -0700	[thread overview]
Message-ID: <7vtxk645vp.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <20130707100949.GC19143@sigill.intra.peff.net> (Jeff King's message of "Sun, 7 Jul 2013 06:09:49 -0400")

Jeff King <peff@peff.net> writes:

> Perhaps we need
>
>   git cat-file --batch-format="%(disk-size) %(object)"
>
> or similar.

I agree with your reasoning.  It may be simpler to give an interface
to ask for which pieces of info, e.g. --batch-cols=size,disksize,
without giving the readers a flexible "format".

> +NOTE: The on-disk size reported is accurate, but care should be taken in
> +drawing conclusions about which refs or objects are responsible for disk
> +usage. The size of a packed non-delta object be much larger than the
> +size of objects which delta against it, but the choice of which object
> +is the base and which is the delta is arbitrary and is subject to change
> +during a repack. Note also that multiple copies of an object may be
> +present in the object database; in this case, it is undefined which
> +copy's size will be reported.

This is a good note to leave to the readers. I was wondering how
valid to accuse that B is taking a lot of space compared to C when
you have three objects A, B and C (in decreasing order of on-disk
footprint) when A is huge and C is a small delta against A and B is
independent.  The role of A and C in their delta chain could easily
be swapped during the next full repack and then C will appear a lot
larger than B.

It might be interesting to measure the total disk footprint of an
entire delta "family" (the objects that delta against the same
base).  You may find out that hello.c with a manageable size have
very many revisions and overall have a larger on-disk footprint than
a single copy of unchanging help.mov clip used in the documentation
does, which may be an interesting observation to make.

  reply	other threads:[~2013-07-07 17:50 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-07 10:01 [RFC/PATCH 0/4] cat-file --batch-disk-sizes Jeff King
2013-07-07 10:03 ` [PATCH 1/4] zero-initialize object_info structs Jeff King
2013-07-07 17:34   ` Junio C Hamano
2013-07-07 10:04 ` [PATCH 2/4] teach sha1_object_info_extended a "disk_size" query Jeff King
2013-07-07 10:09 ` [PATCH 3/4] cat-file: add --batch-disk-sizes option Jeff King
2013-07-07 17:49   ` Junio C Hamano [this message]
2013-07-07 18:19     ` Jeff King
2013-07-08 11:04     ` Duy Nguyen
2013-07-08 12:00       ` Ramkumar Ramachandra
2013-07-08 13:13         ` Duy Nguyen
2013-07-08 13:37           ` Ramkumar Ramachandra
2013-07-09  2:55             ` Duy Nguyen
2013-07-09 10:32               ` Ramkumar Ramachandra
2013-07-10 11:16             ` Jeff King
2013-07-08 16:40           ` Junio C Hamano
2013-07-10 11:04     ` Jeff King
2013-07-11 16:35       ` Junio C Hamano
2013-07-07 21:15   ` brian m. carlson
2013-07-10 10:57     ` Jeff King
2013-07-07 10:14 ` [PATCH 4/4] pack-revindex: radix-sort the revindex Jeff King
2013-07-07 23:52   ` Shawn Pearce
2013-07-08  7:57     ` Jeff King
2013-07-08 15:38       ` Shawn Pearce
2013-07-08 20:50   ` Brandon Casey
2013-07-08 21:35     ` Brandon Casey
2013-07-10 10:57       ` Jeff King
2013-07-10 10:52     ` Jeff King
2013-07-10 11:34 ` [PATCHv2 00/10] cat-file formats/on-disk sizes Jeff King
2013-07-10 11:35   ` [PATCH 01/10] zero-initialize object_info structs Jeff King
2013-07-10 11:35   ` [PATCH 02/10] teach sha1_object_info_extended a "disk_size" query Jeff King
2013-07-10 11:36   ` [PATCH 03/10] t1006: modernize output comparisons Jeff King
2013-07-10 11:38   ` [PATCH 04/10] cat-file: teach --batch to stream blob objects Jeff King
2013-07-10 11:38   ` [PATCH 05/10] cat-file: refactor --batch option parsing Jeff King
2013-07-10 11:45   ` [PATCH 06/10] cat-file: add --batch-check=<format> Jeff King
2013-07-10 11:57     ` Eric Sunshine
2013-07-10 14:51     ` Ramkumar Ramachandra
2013-07-11 11:24       ` Jeff King
2013-07-10 11:46   ` [PATCH 07/10] cat-file: add %(objectsize:disk) format atom Jeff King
2013-07-10 11:48   ` [PATCH 08/10] cat-file: split --batch input lines on whitespace Jeff King
2013-07-10 15:29     ` Ramkumar Ramachandra
2013-07-11 11:36       ` Jeff King
2013-07-11 17:42         ` Junio C Hamano
2013-07-11 20:45         ` [PATCHv3 " Jeff King
2013-07-10 11:50   ` [PATCH 09/10] pack-revindex: use unsigned to store number of objects Jeff King
2013-07-10 11:55   ` [PATCH 10/10] pack-revindex: radix-sort the revindex Jeff King
2013-07-10 12:00     ` Jeff King
2013-07-10 13:17     ` Ramkumar Ramachandra
2013-07-11 11:03       ` Jeff King
2013-07-10 17:10     ` Brandon Casey
2013-07-11 11:17       ` Jeff King
2013-07-11 12:16     ` [PATCHv3 " Jeff King
2013-07-11 21:12       ` Brandon Casey

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7vtxk645vp.fsf@alter.siamese.dyndns.org \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=peff@peff.net \
    --subject='Re: [PATCH 3/4] cat-file: add --batch-disk-sizes option' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).