skip_prefix(): scan prefix only once

dakhubgit · gitster · commit ba399c46d9d3 · 2014-03-03T15:38:14.000-08:00
Signed-off-by: David Kastrup &lt;dak@gnu.org&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/git-compat-util.h b/git-compat-util.h
@@ -357,8 +357,11 @@ extern int suffixcmp(const char *str, const char *suffix);
 
 static inline const char *skip_prefix(const char *str, const char *prefix)
 {
-	size_t len = strlen(prefix);
-	return strncmp(str, prefix, len) ? NULL : str + len;
+	do {
+		if (!*prefix)
+			return str;
+	} while (*str++ == *prefix++);
+	return NULL;
 }
 
 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)

Original file line number	Diff line number	Diff line change
`@@ -357,8 +357,11 @@ extern int suffixcmp(const char str, const char suffix);`
`357`	`357`
`358`	`358`	`static inline const char skip_prefix(const char str, const char *prefix)`
`359`	`359`	`{`
`360`		`- size_t len = strlen(prefix);`
`361`		`- return strncmp(str, prefix, len) ? NULL : str + len;`
	`360`	`+ do {`
	`361`	`+ if (!*prefix)`
	`362`	`+ return str;`
	`363`	`+ } while (str++ == prefix++);`
	`364`	`+ return NULL;`
`362`	`365`	`}`
`363`	`366`
`364`	`367`	`#if defined(NO_MMAP) \|\| defined(USE_WIN32_MMAP)`