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From: "Martin Ågren" <martin.agren@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Git Mailing List <git@vger.kernel.org>,
	Emily Shaffer <emilyshaffer@google.com>,
	Jeff King <peff@peff.net>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>
Subject: Re: [PATCH v2 3/4] grep: copy struct in one fell swoop
Date: Thu, 26 Nov 2020 21:25:57 +0100
Message-ID: <CAN0heSp2L4Q0pcn8V5hAKzXF6szZgpGqncLNYZOq5tmM7EucOQ@mail.gmail.com> (raw)
In-Reply-To: <xmqqlfepg9dq.fsf@gitster.c.googlers.com>

On Wed, 25 Nov 2020 at 08:53, Junio C Hamano <gitster@pobox.com> wrote:
>
> Martin Ågren <martin.agren@gmail.com> writes:
>
> >   /*
> >    * The instance of grep_opt that we set up here is copied by
> >    * grep_init() to be used by each individual invocation.
> >    * When populating a new field of this structure here,
> >    * be sure to think about ownership (i.e. a shallow copy in
> >    * grep_init() may not be what you want).
> >    */
>
> I find the text near the end of both my version and yours a bit
> unsatisfying.  One thing I care about is not to mislead readers to
> think that the way grep_init() copies the singleton template is
> correct and sacred and they need to design their data structure to
> be compatible with the shallow copying.  We'd want it to be clear
> that it is expected that they will deep copy the field, and release
> it once individual invocation is done, when they need a new field
> that won't work well with shallow copying.  Perhaps "may not be wnat
> you want" is explicit enough, but I dunno.

I understand your concern. Here's what I'm considering using:

  /*
   * The instance of grep_opt that we set up here is copied by
   * grep_init() to be used by each individual invocation.
   * When populating a new field of this structure here, be
   * sure to think about ownership -- e.g., you might need to
   * override the shallow copy in grep_init() with a deep copy.
   */

I'm not going into the releasing of those resources, but hopefully
that part can be left to the reader.

Other suggestions welcome, of course. I hope to get around to rerolling
this on the weekend.

Martin

  reply	other threads:[~2020-11-26 20:41 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-21 18:31 [PATCH 0/4] grep: retire `init_grep_defaults()` Martin Ågren
2020-11-21 18:31 ` [PATCH 1/4] grep: don't set up a "default" repo for grep Martin Ågren
2020-11-21 18:31 ` [PATCH 2/4] grep: use designated initializers for `grep_defaults` Martin Ågren
2020-11-21 18:31 ` [PATCH 3/4] grep: simplify color setup Martin Ågren
2020-11-21 20:23   ` Jeff King
2020-11-21 20:52     ` Martin Ågren
2020-11-21 22:46     ` Junio C Hamano
2020-11-24  6:54       ` Jeff King
2020-11-21 18:31 ` [PATCH 4/4] MyFirstObjectWalk: drop `init_walken_defaults()` Martin Ågren
2020-11-23 11:03 ` [PATCH 0/4] grep: retire `init_grep_defaults()` Johannes Schindelin
2020-11-24 21:04 ` [PATCH v2 0/4] grep: simplify "grep defaults" handling Martin Ågren
2020-11-24 21:04   ` [PATCH v2 1/4] grep: don't set up a "default" repo for grep Martin Ågren
2020-11-24 21:04   ` [PATCH v2 2/4] grep: use designated initializers for `grep_defaults` Martin Ågren
2020-11-24 21:04   ` [PATCH v2 3/4] grep: copy struct in one fell swoop Martin Ågren
2020-11-24 22:34     ` Junio C Hamano
2020-11-25  6:25       ` Martin Ågren
2020-11-25  7:53         ` Junio C Hamano
2020-11-26 20:25           ` Martin Ågren [this message]
2020-11-24 21:04   ` [PATCH v2 4/4] MyFirstObjectWalk: drop `init_walken_defaults()` Martin Ågren
2020-11-25  9:27   ` [PATCH v2 0/4] grep: simplify "grep defaults" handling Ævar Arnfjörð Bjarmason
2020-11-29 19:52   ` [PATCH v3 " Martin Ågren
2020-11-29 19:52     ` [PATCH v3 1/4] grep: don't set up a "default" repo for grep Martin Ågren
2020-11-29 19:52     ` [PATCH v3 2/4] grep: use designated initializers for `grep_defaults` Martin Ågren
2020-11-29 19:52     ` [PATCH v3 3/4] grep: copy struct in one fell swoop Martin Ågren
2020-11-29 19:52     ` [PATCH v3 4/4] MyFirstObjectWalk: drop `init_walken_defaults()` Martin Ågren
2020-12-01  4:46     ` [PATCH v3 0/4] grep: simplify "grep defaults" handling Junio C Hamano

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