From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Compressing compressed files
Date: Mon, 01 Aug 2016 18:02:54 +0200
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References: <20160801085839.GA2426@solar>
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In-Reply-To: <20160801085839.GA2426@solar> (Andreas Enge's message of "Mon, 1
	Aug 2016 10:58:39 +0200")
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To: Andreas Enge <andreas@enge.fr>
Cc: guix-devel@gnu.org

Hi!

Andreas Enge <andreas@enge.fr> skribis:

> I am seeing this funny command being executed on one of the build machine=
s:
>    bash -c guix archive --export /gnu/store/06g54r7am7ka96d7jydgmayfyqgx1=
s1l-cfe-3.5.2.src.tar.xz | xz -c
>
> Would it be difficult to prevent re-compressing of already compressed
> source when offloading? Especially since xz is rather expensive, and more
> or less occupies one core of the arm machines.

This all takes place in (guix scripts offload) and should be relatively
easy to modify (see commit 5ef9d7deeab348e0f714f91a3c02ce4b72bbe3c1 for
an example).

[Time passes=E2=80=A6]

I thought it would be quicker to fix it but was proved wrong, because
=E2=80=98guix substitute=E2=80=99 expects to be able to pass non-file ports=
 to
=E2=80=98decompressed-ports=E2=80=99, which means we cannot just use =E2=80=
=98duplicate-port=E2=80=99
there.  Anyway, I=E2=80=99ve pushed =E2=80=98wip-offload-compression=E2=80=
=99 and we=E2=80=99ll look at
it again after the release.

Thanks,
Ludo=E2=80=99.