From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Date: Sat, 29 Dec 2007 19:22:14 +0000 (+0100)
Subject: Optimize prefixcmp()
X-Git-Tag: v1.5.4-rc3~63
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=99a6a97b1bf866d7050e8afb137b4b29507f0caa;p=git.git

Optimize prefixcmp()

Certain codepaths (notably "git log --pretty=format...") use
prefixcmp() extensively, with very short prefixes.  In those cases,
calling strlen() is a wasteful operation, so avoid it.

Initial patch by Marco Costalba.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/git-compat-util.h b/git-compat-util.h
index 79eb10eac..7059cbdab 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -398,7 +398,11 @@ static inline int sane_case(int x, int high)
 
 static inline int prefixcmp(const char *str, const char *prefix)
 {
-	return strncmp(str, prefix, strlen(prefix));
+	for (; ; str++, prefix++)
+		if (!*prefix)
+			return 0;
+		else if (*str != *prefix)
+			return (unsigned char)*prefix - (unsigned char)*str;
 }
 
 static inline int strtoul_ui(char const *s, int base, unsigned int *result)