From: Pierre Habouzit <madcoder@debian.org>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] Rework strbuf API and semantics.
Date: Thu, 06 Sep 2007 12:22:36 +0200 [thread overview]
Message-ID: <20070906102236.GE8451@artemis.corp> (raw)
In-Reply-To: <7vtzq89kky.fsf@gitster.siamese.dyndns.org>
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On Thu, Sep 06, 2007 at 10:03:57AM +0000, Junio C Hamano wrote:
> Pierre Habouzit <madcoder@debian.org> writes:
>
> > diff --git a/strbuf.c b/strbuf.c
> > ...
> > +void strbuf_addvf(struct strbuf *sb, const char *fmt, va_list ap)
> > +{
> > + size_t len;
> > + va_list ap2;
> > +
> > + va_copy(ap2, ap);
> > +
> > + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
> > + if (len < 0) {
> > + len = 0;
> > + }
> > + if (len >= sb->alloc - sb->len) {
> > + strbuf_grow(sb, len);
> > + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap2);
> > + if (len >= sb->alloc - sb->len) {
> > + len = sb->alloc - sb->len - 1;
> > + }
> > + }
> > + sb->len = sb->len + len;
> > + sb->buf[sb->len] = '\0';
> > }
>
> Hmmmmm... Didn't we recently had a patch that used va_copy()
> which was not available somewhere and was shot down?
>
> Instead of that nice inline strbuf_addf(), you may have to do
> something like:
>
> strbuf_addf(..., fmt, ...) {
> va_list ap;
>
> va_start(ap, fmt);
> len = vsnprintf(...);
> va_end(ap);
> if (len >= sb_avail(sb)) {
> strbuf_grow(sb, len);
> va_start(ap, fmt);
> len = vsnprintf(...);
> va_end(ap);
> if (len >= sb_avail(sb))
> gaah();
> }
> sb->len += len;
> sb->buf[sb->len] = '\0';
> }
I'll do that.
> > +ssize_t strbuf_read(struct strbuf *sb, int fd)
> > +{
> > + size_t oldlen = sb->len;
> > +
> > + for (;;) {
> > + ssize_t cnt;
> > +
> > + strbuf_grow(sb, 8192);
> > + cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
> > + if (cnt < 0) {
> > + sb->buf[sb->len = oldlen] = '\0';
>
> Assignment inside array subscript is very hard to read.
> Besides, what's the error semantics? On error, this behaves as
> if no bytes are read (i.e. partial read results in the initial
> round is lost forever)?
Yes that is the semantics, because it's how it was used everywhere in
git: either we were able to load all the data from the file descriptor,
or weren't able to and the next thing we do is to die().
Maybe I should call the function strbuf_xread() instead ?
--
·O· Pierre Habouzit
··O madcoder@debian.org
OOO http://www.madism.org
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next prev parent reply other threads:[~2007-09-06 10:22 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-02 22:42 strbuf API Pierre Habouzit
2007-09-03 5:43 ` Johan Herland
2007-09-03 8:46 ` Pierre Habouzit
2007-09-04 1:52 ` Miles Bader
2007-09-04 8:47 ` strbuf new semantics, let's give it a try Pierre Habouzit
2007-09-04 8:47 ` [PATCH] Rework strbuf API and semantics Pierre Habouzit
2007-09-04 11:11 ` Johannes Schindelin
2007-09-04 11:53 ` Pierre Habouzit
2007-09-04 13:34 ` Andreas Ericsson
2007-09-04 14:01 ` Pierre Habouzit
2007-09-04 15:44 ` Johannes Schindelin
2007-09-04 16:18 ` Pierre Habouzit
2007-09-04 17:18 ` Wincent Colaiuta
2007-09-04 14:01 ` [PATCH] Simplify strbuf uses in fast-import.c using the proper functions Pierre Habouzit
2007-09-04 23:46 ` René Scharfe
2007-09-04 23:46 ` René Scharfe
2007-09-05 7:48 ` Pierre Habouzit
2007-09-05 8:05 ` Junio C Hamano
2007-09-05 8:57 ` Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Rework strbuf API and semantics Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Simplify strbuf uses in archive-tar.c using the proper functions Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Simplify strbuf uses in fast-import.c " Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Use proper strbuf API, and also simplify cmd_data code Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Simplify write_tree using strbuf's Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Further strbuf re-engineering Pierre Habouzit
2007-09-05 19:18 ` [PATCH] Eradicate yet-another-buffer implementation in buitin-rerere.c Pierre Habouzit
2007-09-05 19:18 ` [PATCH] More strbuf uses in cache-tree.c Pierre Habouzit
2007-09-19 8:05 ` [PATCH] Further strbuf re-engineering Junio C Hamano
2007-09-05 19:21 ` [PATCH] Simplify strbuf uses in fast-import.c using the proper functions Pierre Habouzit
2007-09-19 8:06 ` [PATCH] Simplify strbuf uses in archive-tar.c " Junio C Hamano
2007-09-19 8:36 ` Pierre Habouzit
2007-09-06 9:31 ` [PATCH] Rework strbuf API and semantics Junio C Hamano
2007-09-06 9:49 ` Pierre Habouzit
2007-09-06 10:03 ` Junio C Hamano
2007-09-06 10:22 ` Pierre Habouzit [this message]
2007-09-04 14:01 ` [PATCH] Use proper strbuf API, and also simplify cmd_data code Pierre Habouzit
2007-09-05 4:44 ` [PATCH] Rework strbuf API and semantics Miles Bader
2007-09-04 8:48 ` [PATCH] Add strbuf_fread, use it in fast-import.c Pierre Habouzit
2007-09-03 8:32 ` strbuf API Matthieu Moy
2007-09-03 8:49 ` Pierre Habouzit
2007-09-03 9:02 ` Matthieu Moy
2007-09-03 9:18 ` Junio C Hamano
2007-09-03 11:53 ` Pierre Habouzit
2007-09-03 12:29 ` Johannes Schindelin
2007-09-06 11:20 ` strbuf new API, take 2 for inclusion Pierre Habouzit
2007-09-06 11:20 ` [PATCH 1/7] Rework strbuf API and semantics Pierre Habouzit
2007-09-06 11:20 ` [PATCH 2/7] Simplify strbuf uses in archive-tar.c using the proper functions Pierre Habouzit
2007-09-06 11:20 ` [PATCH 3/7] Use proper strbuf API, and also simplify cmd_data code Pierre Habouzit
2007-09-06 11:20 ` [PATCH 4/7] Simplify write_tree using strbuf's Pierre Habouzit
2007-09-06 11:20 ` [PATCH 5/7] Further strbuf re-engineering Pierre Habouzit
2007-09-06 11:20 ` [PATCH 6/7] Eradicate yet-another-buffer implementation in buitin-rerere.c Pierre Habouzit
2007-09-06 11:20 ` [PATCH 7/7] More strbuf uses in cache-tree.c Pierre Habouzit
2007-09-06 14:05 ` [PATCH 6/7] Eradicate yet-another-buffer implementation in buitin-rerere.c Johannes Schindelin
2007-09-06 17:17 ` Pierre Habouzit
2007-09-06 20:16 ` David Kastrup
2007-09-06 20:54 ` Pierre Habouzit
2007-09-07 8:03 ` Junio C Hamano
2007-09-07 9:02 ` Pierre Habouzit
2007-09-06 17:59 ` [PATCH 2/7] Simplify strbuf uses in archive-tar.c using the proper functions Kristian Høgsberg
2007-09-06 18:08 ` Pierre Habouzit
2007-09-06 18:18 ` Kristian Høgsberg
2007-09-06 18:27 ` Pierre Habouzit
2007-09-06 22:54 ` René Scharfe
2007-09-06 14:09 ` [PATCH 1/7] Rework strbuf API and semantics Johannes Schindelin
2007-09-06 14:21 ` Jeff King
2007-09-06 14:44 ` David Kastrup
2007-09-06 14:50 ` Jeff King
2007-09-06 15:06 ` David Kastrup
2007-09-06 15:36 ` Jeff King
2007-09-06 15:53 ` David Kastrup
2007-09-06 15:45 ` Johannes Sixt
2007-09-06 14:43 ` David Kastrup
2007-09-06 14:52 ` Jeff King
2007-09-06 17:49 ` Kristian Høgsberg
2007-09-06 12:58 ` strbuf new API, take 2 for inclusion Jeff King
2007-09-06 17:15 ` Pierre Habouzit
2007-09-06 17:16 ` Jeff King
2007-09-06 17:19 ` Pierre Habouzit
2007-09-08 11:53 ` Use strbufs in commit.c (pretty printing) Pierre Habouzit
2007-09-08 11:53 ` [PATCH 1/3] Add strbuf_rtrim (to remove trailing spaces) Pierre Habouzit
2007-09-08 11:53 ` [PATCH 2/3] Change semantics of interpolate to work like snprintf Pierre Habouzit
2007-09-08 11:53 ` [PATCH 3/3] Rework pretty_print_commit to use strbufs instead of custom buffers Pierre Habouzit
2007-09-08 11:59 ` David Kastrup
2007-09-08 12:17 ` Pierre Habouzit
2007-09-08 12:28 ` Pierre Habouzit
2007-09-08 18:40 ` René Scharfe
2007-09-08 18:49 ` Pierre Habouzit
2007-09-08 16:18 ` [PATCH 1/3] Add strbuf_rtrim (to remove trailing spaces) René Scharfe
2007-09-08 22:53 ` Pierre Habouzit
2007-09-08 23:44 ` Pierre Habouzit
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