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From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Michael Haggerty <mhagger@alum.mit.edu>,
	William Duclot <william.duclot@ensimag.grenoble-inp.fr>,
	git@vger.kernel.org, antoine.queru@ensimag.grenoble-inp.fr,
	francois.beutin@ensimag.grenoble-inp.fr,
	Johannes.Schindelin@gmx.de, mh@glandium.org
Subject: Re: [PATCH V2 3/3] strbuf: allow to use preallocated memory
Date: Wed, 08 Jun 2016 12:48:36 -0700	[thread overview]
Message-ID: <xmqq37onlawb.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20160608191918.GB19572@sigill.intra.peff.net> (Jeff King's message of "Wed, 8 Jun 2016 15:19:18 -0400")

Jeff King <peff@peff.net> writes:

> That made me wonder if we could repeatedly reuse a buffer attached to
> the file descriptor. And indeed, isn't that what stdio is? The whole
> reason this buffer exists is because we are using a direct descriptor
> write. If we switched this function to use fprintf(), we'd avoid the
> whole buffer question, have a fixed cap on our memory use (since we just
> flush anytime the buffer is full) _and_ we'd reduce the number of
> write syscalls we're making by almost a factor of 100.

The primary reason why we avoid stdio in the lower level part of I/O
is that the error reporting and handling is horrible.

e.g. c.f. http://article.gmane.org/gmane.comp.version-control.git/27019

Otherwise, I'd agree with your "Why aren't we using stdio if
counting and avoiding overflow is so hard?".

  parent reply	other threads:[~2016-06-08 19:49 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-06 15:13 [PATCH V2 0/3] strbuf: improve API William Duclot
2016-06-06 15:13 ` [PATCH V2 1/3] strbuf: add tests William Duclot
2016-06-06 16:11   ` Matthieu Moy
2016-06-07  8:44   ` Johannes Schindelin
2016-06-06 15:13 ` [PATCH V2 2/3] pretty.c: rename strbuf_wrap() function William Duclot
2016-06-06 16:12   ` Matthieu Moy
2016-06-07  9:04   ` Johannes Schindelin
2016-06-06 15:13 ` [PATCH V2 3/3] strbuf: allow to use preallocated memory William Duclot
2016-06-06 16:17   ` Matthieu Moy
2016-06-06 17:19   ` Junio C Hamano
2016-06-06 20:39     ` William Duclot
2016-06-06 22:44       ` Junio C Hamano
2016-06-06 22:58         ` Jeff King
2016-06-06 23:24           ` Junio C Hamano
2016-06-06 23:25             ` Junio C Hamano
2016-06-06 23:30             ` Jeff King
2016-06-07  9:06             ` William Duclot
2016-06-07 18:10               ` Junio C Hamano
2016-06-08 16:20               ` Michael Haggerty
2016-06-08 18:07                 ` Junio C Hamano
2016-06-08 19:19                 ` Jeff King
2016-06-08 19:42                   ` [PATCH] send-pack: use buffered I/O to talk to pack-objects Jeff King
2016-06-09 12:10                     ` Matthieu Moy
2016-06-09 14:34                       ` Ramsay Jones
2016-06-09 17:12                         ` Jeff King
2016-06-09 22:40                           ` Ramsay Jones
2016-06-09 16:40                       ` Junio C Hamano
2016-06-09 17:14                         ` Jeff King
2016-06-09 17:22                         ` Matthieu Moy
2016-06-08 19:48                   ` Junio C Hamano [this message]
2016-06-08 19:52                     ` [PATCH V2 3/3] strbuf: allow to use preallocated memory Jeff King
2016-06-08 23:05                       ` Junio C Hamano

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