From: Shawn O. Pearce <spearce@spearce.org>
Date: Sat, 26 May 2007 05:24:40 +0000 (-0400)
Subject: Micro-optimize prepare_alt_odb
X-Git-Tag: v1.5.3-rc0~171^2~6
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=7dc24aa5a62cc5f77e6637674581c837f4bdf78e;p=git.git

Micro-optimize prepare_alt_odb

Calling getenv() is not that expensive, but its also not free,
and its certainly not cheaper than testing to see if alt_odb_tail
is not null.

Because we are calling prepare_alt_odb() from within find_sha1_file
every time we cannot find an object file locally we want to skip out
of prepare_alt_odb() as early as possible once we have initialized
our alternate list.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
---

diff --git a/sha1_file.c b/sha1_file.c
index 6a5ba6350..a3637d7e5 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -376,11 +376,12 @@ void prepare_alt_odb(void)
 {
 	const char *alt;
 
+	if (alt_odb_tail)
+		return;
+
 	alt = getenv(ALTERNATE_DB_ENVIRONMENT);
 	if (!alt) alt = "";
 
-	if (alt_odb_tail)
-		return;
 	alt_odb_tail = &alt_odb_list;
 	link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);