git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / Atom feed
From: Chris Torek <chris.torek@gmail.com>
To: "René Scharfe" <l.s.r@web.de>
Cc: Git Mailing List <git@vger.kernel.org>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH] upload-pack: use buffered I/O to talk to rev-list
Date: Sun, 2 Aug 2020 09:03:23 -0700
Message-ID: <CAPx1GvdJ-4Yyf7Vm1OdhaW2TZp77HOfGxoGw0R2fKfEuHQkqOg@mail.gmail.com> (raw)
In-Reply-To: <6722ade6-971e-7ecc-e8f0-7f595ca0b0ff@web.de>

One suggestion here:

On Sun, Aug 2, 2020 at 7:41 AM René Scharfe <l.s.r@web.de> wrote:
> Like f0bca72dc77 (send-pack: use buffered I/O to talk to pack-objects,
> 2016-06-08), significantly reduce the number of system calls and
> simplify the code for sending object IDs to rev-list by using stdio's
> buffering and handling errors after the loops.
>
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
>  upload-pack.c | 21 +++++++--------------
>  1 file changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/upload-pack.c b/upload-pack.c
> index 86737410709..9f616c2c6a6 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c

[snip]

> @@ -640,12 +636,11 @@ static int do_reachable_revlist(struct child_process *cmd,
>                 }
>                 if (reachable && o->type == OBJ_COMMIT)
>                         o->flags |= TMP_MARK;
> -               memcpy(namebuf, oid_to_hex(&o->oid), hexsz);
> -               if (write_in_full(cmd->in, namebuf, hexsz + 1) < 0)
> -                       goto error;
> +               fprintf(cmd_in, "%s\n", oid_to_hex(&o->oid));

The fprintf() call here *can* return an error, e.g., if the
connection has died.  If it does, it should set things up so that
a later ferror(cmd_in) returns true.

>         }
> -       close(cmd->in);
>         cmd->in = -1;
> +       if (fclose(cmd_in))
> +               goto error;

The fclose() call doesn't necessarily check ferror().  (The
FreeBSD stdio in particular definitely does not.)  It might
be better to use:

    failure = ferror(cmd_in);
    failure |= fclose(cmd_in);
    if (failure) ...

here, or similar.  (The temporary variable is not needed,
but someone might assume `if (ferror(fp) | fclose(fp))` is
a typo for `if (ferror(fp) || fclose(fp))`.)

(Note: my sample isn't properly indented as gmail does not
let me insert tabs easily)

Chris

  reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-02 14:38 René Scharfe
2020-08-02 16:03 ` Chris Torek [this message]
2020-08-03 14:00   ` René Scharfe
2020-08-03 15:54     ` Chris Torek
2020-08-03 18:15   ` Johannes Sixt

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=CAPx1GvdJ-4Yyf7Vm1OdhaW2TZp77HOfGxoGw0R2fKfEuHQkqOg@mail.gmail.com \
    --to=chris.torek@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=l.s.r@web.de \
    /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

git@vger.kernel.org list mirror (unofficial, one of many)

Archives are clonable:
	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

Example config snippet for mirrors

Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git
	nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git

 note: .onion URLs require Tor: https://www.torproject.org/

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git