From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: =?utf-8?Q?=E2=80=98core-updates=E2=80=99?= is back!
Date: Wed, 30 Aug 2017 11:58:35 +0200
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References: <878ti3uzaz.fsf@gnu.org> <87val6zqg0.fsf@igalia.com>
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iyzsong@member.fsf.org (=E5=AE=8B=E6=96=87=E6=AD=A6) skribis:

> Andy Wingo <wingo@igalia.com> writes:
>
>> On Tue 29 Aug 2017 00:01, ludo@gnu.org (Ludovic Court=C3=A8s) writes:
>>
>>> Yup, I just created a new =E2=80=98core-updates=E2=80=99 branch by push=
ing
>>> <https://bugs.gnu.org/27849>.  Enjoy!
>>>
>>> Let=E2=80=99s freeze in one month, say Oct. 1st?
>>
>> It would be pretty cool if we could fix our O(n^2) problems in search
>> paths in this core-updates -- basically whenever you go to create an
>> environment, instead of making e.g. VAR=3DA:B:C:..., for all VARs
>> (LIBRARY_PATH, PKG_CONFIG_PATH, etc), instead we make a union directory
>> Z containing the union of A, B, C, etc and set VAR=3DZ.  The goal would =
be
>> to fix quadratic run-time lookup costs by replacing it with a
>> compile-time computation.  This applies to many lookups: PATH, -rpath,
>> etc.
>
> The runtime references scanner of daemon will be inefficient if the
> union gets recorded with all the inputs contained, and we likely won't
> apply this to packages with multiple outputs (eg: fcitx) which will make
> every output including the union into its runtime reference.

Indeed, good point.

Ludo=E2=80=99.