From 9d9eb307165938a8c829ebd518434850cc0280a6 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Fri, 10 Jan 2014 10:45:22 +0100 Subject: [PATCH] talloc: Tune talloc_vasprintf vsnprintf is significantly more expensive than memcpy. For the common case where the string we print is less than a kilobyte, avoid the second vsnprintf. Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison Autobuild-User(master): Jeremy Allison Autobuild-Date(master): Thu May 15 12:49:14 CEST 2014 on sn-devel-104 (cherry picked from commit 593c8103af5a5ed6b3c915369fed5b90efb42c25) --- lib/talloc/talloc.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/lib/talloc/talloc.c b/lib/talloc/talloc.c index 1cb4d7dead79..2a5406e11d02 100644 --- a/lib/talloc/talloc.c +++ b/lib/talloc/talloc.c @@ -2356,11 +2356,11 @@ _PUBLIC_ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) int len; char *ret; va_list ap2; - char c; + char buf[1024]; /* this call looks strange, but it makes it work on older solaris boxes */ va_copy(ap2, ap); - len = vsnprintf(&c, 1, fmt, ap2); + len = vsnprintf(buf, sizeof(buf), fmt, ap2); va_end(ap2); if (unlikely(len < 0)) { return NULL; @@ -2369,9 +2369,13 @@ _PUBLIC_ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) ret = (char *)__talloc(t, len+1); if (unlikely(!ret)) return NULL; - va_copy(ap2, ap); - vsnprintf(ret, len+1, fmt, ap2); - va_end(ap2); + if (len < sizeof(buf)) { + memcpy(ret, buf, len+1); + } else { + va_copy(ap2, ap); + vsnprintf(ret, len+1, fmt, ap2); + va_end(ap2); + } _talloc_set_name_const(ret, ret); return ret; -- 2.34.1