From: Junio C Hamano <gitster@pobox.com>
To: Lukas Fleischer <lfleischer@lfos.de>
Cc: git@vger.kernel.org, Nicolas Pitre <nico@fluxnic.net>,
Johannes Schindelin <Johannes.Schindelin@gmx.de>,
Jeff King <peff@peff.net>
Subject: Re: [PATCH v4] Refactor recv_sideband()
Date: Tue, 28 Jun 2016 09:57:30 -0700 [thread overview]
Message-ID: <xmqqa8i59rph.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20160628043526.19403-1-lfleischer@lfos.de> (Lukas Fleischer's message of "Tue, 28 Jun 2016 06:35:26 +0200")
Lukas Fleischer <lfleischer@lfos.de> writes:
> Before this patch, we used character buffer manipulations to split
> messages from the sideband at line breaks and insert "remote: " at the
> beginning of each line, using the packet size to determine the end of a
> message. However, since it is safe to assume that diagnostic messages
> from the sideband never contain NUL characters, we can also
> NUL-terminate the buffer, use strpbrk() for splitting lines and use
> format strings to insert the prefix.
>
> A strbuf is used for accumulating the output which is then printed using
> a single fprintf() call with a single conversion specifier per line,
> such that the atomicity of the output is preserved. See 9ac13ec (atomic
> write for sideband remote messages, 2006-10-11) for details.
>
> Helped-by: Jeff King <peff@peff.net>
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Helped-by: Nicolas Pitre <nico@fluxnic.net>
> Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
> ---
> Changes since v3:
> * The new code always frees the strbuf used for the output.
> * Switched back to fprintf() to support ANSI codes under Windows.
> * Added a comment on the tradeoff between atomicity and Windows support.
With input from Dscho that recent Git-for-Windows does the right
thing without limiting us to use only a subset of stdio, perhaps we
would want to squash something like this in.
diff --git a/sideband.c b/sideband.c
index 226a8c2..72e2c5c 100644
--- a/sideband.c
+++ b/sideband.c
@@ -58,13 +58,12 @@ int recv_sideband(const char *me, int in_stream, int out)
* Append a suffix to each nonempty line to clear the
* end of the screen line.
*
- * The output is accumulated in a buffer and each line
- * is printed to stderr using fprintf() with a single
- * conversion specifier. This is a "best effort"
- * approach to supporting both inter-process atomicity
- * (single conversion specifiers are likely to end up
- * in single atomic write() system calls) and the ANSI
- * control code emulation under Windows.
+ * The output is accumulated in a buffer and
+ * each line is printed to stderr using
+ * fwrite(3). This is a "best effort"
+ * approach to suppor inter-process atomicity
+ * (single fwrite(3) call is likely to end up
+ * in single atomic write() system calls).
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
@@ -75,8 +74,7 @@ int recv_sideband(const char *me, int in_stream, int out)
} else {
strbuf_addf(&outbuf, "%c", *brk);
}
- fprintf(stderr, "%.*s", (int)outbuf.len,
- outbuf.buf);
+ fwrite(output.buf, 1, output.len, stderr);
strbuf_reset(&outbuf);
strbuf_addf(&outbuf, "%s", PREFIX);
@@ -98,7 +96,7 @@ int recv_sideband(const char *me, int in_stream, int out)
}
if (outbuf.len > 0)
- fprintf(stderr, "%.*s", (int)outbuf.len, outbuf.buf);
+ fwrite(output.buf, 1, output.len, stderr);
strbuf_release(&outbuf);
return retval;
}
next prev parent reply other threads:[~2016-06-28 16:57 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-13 19:52 [PATCH] Refactor recv_sideband() Lukas Fleischer
2016-06-13 21:07 ` Nicolas Pitre
2016-06-14 13:44 ` Johannes Schindelin
2016-06-14 15:04 ` Nicolas Pitre
2016-06-14 15:30 ` Johannes Schindelin
[not found] ` <Cq7rbYgOpb0CVCq7sbGmpL@videotron.ca>
2016-06-14 16:43 ` Nicolas Pitre
2016-06-14 17:09 ` Nicolas Pitre
[not found] ` <CsLdb3qLMBok7CsLebwX38@videotron.ca>
2016-06-14 17:55 ` Nicolas Pitre
2016-06-14 18:11 ` Junio C Hamano
2016-06-14 19:11 ` Lukas Fleischer
2016-06-14 19:16 ` Junio C Hamano
[not found] ` <Ct7VbfLfTHEALCt7Wbh8Xs@videotron.ca>
2016-06-14 20:10 ` Nicolas Pitre
2016-06-14 21:00 ` [PATCH v2] " Lukas Fleischer
2016-06-14 21:11 ` Lukas Fleischer
2016-06-14 21:25 ` Junio C Hamano
2016-06-15 3:44 ` Jeff King
[not found] ` <146597489449.32143.1327156804178869158@s-8d3a2dc3.on.site.uni-stuttgart.de>
2016-06-19 10:48 ` Lukas Fleischer
2016-06-24 15:31 ` Jeff King
2016-06-24 17:45 ` Johannes Schindelin
2016-06-24 18:14 ` Jeff King
2016-06-24 18:32 ` Junio C Hamano
2016-06-27 10:58 ` Lukas Fleischer
2016-06-27 15:54 ` Junio C Hamano
2016-06-27 16:16 ` Jeff King
2016-06-27 17:50 ` Junio C Hamano
2016-06-27 20:34 ` Lukas Fleischer
2016-06-27 20:47 ` Nicolas Pitre
2016-06-28 4:01 ` Lukas Fleischer
2016-06-28 5:20 ` Junio C Hamano
2016-06-28 10:04 ` Johannes Schindelin
2016-06-28 10:05 ` Johannes Schindelin
2016-06-28 15:13 ` Junio C Hamano
2016-06-28 16:21 ` Johannes Schindelin
2016-06-24 20:07 ` Dennis Kaarsemaker
2016-06-22 5:29 ` [PATCH v3] " Lukas Fleischer
2016-06-22 15:02 ` Nicolas Pitre
2016-06-22 22:47 ` Nicolas Pitre
2016-06-23 17:35 ` Lukas Fleischer
2016-06-23 18:59 ` Nicolas Pitre
2016-06-28 4:35 ` [PATCH v4] " Lukas Fleischer
2016-06-28 16:57 ` Junio C Hamano [this message]
2016-06-28 17:24 ` Junio C Hamano
2016-06-28 17:46 ` Nicolas Pitre
2016-06-28 18:13 ` Junio C Hamano
2016-06-28 18:28 ` Nicolas Pitre
2016-06-28 19:51 ` Junio C Hamano
2016-06-28 20:36 ` Nicolas Pitre
2016-06-28 21:09 ` Junio C Hamano
2016-06-28 21:44 ` Nicolas Pitre
2016-06-28 22:33 ` Junio C Hamano
2016-06-28 22:47 ` Junio C Hamano
2016-06-29 3:00 ` Junio C Hamano
2016-06-29 3:41 ` Nicolas Pitre
2016-06-29 2:02 ` Nicolas Pitre
2016-06-29 16:40 ` Junio C Hamano
2016-06-30 6:16 ` Lukas Fleischer
2016-07-01 20:01 ` Junio C Hamano
2016-07-05 20:35 ` Nicolas Pitre
2016-07-06 21:11 ` Junio C Hamano
2016-07-07 0:56 ` Nicolas Pitre
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