Re: [PATCH] optimize path_relative()

On Fri, Jun 04, 2010 at 09:44:43AM +0200, Clemens Buchacher wrote:

+static const char *path_relative(const char *in, int len,
+				 struct strbuf *sb, const char *prefix,
+				 int prefix_len)
 {
+	int off, i;
+
 	if (len < 0)
 		len = strlen(in);
 	if (prefix && prefix_len < 0)
 		prefix_len = strlen(prefix);
 
-	strbuf_setlen(out, 0);
-	strbuf_grow(out, len);
+	off = 0;
+	i = 0;
+	while (i < prefix_len && i < len && prefix[i] == in[i]) {
+		if (prefix[i] == '/')
+			off = i + 1;
+		i++;
+	}
+	in += off;
+	len -= off;
 
-	if (prefix_len > 0) {
-		int off = 0, i = 0;
-		while (i < prefix_len && i < len && prefix[i] == in[i]) {
-			if (prefix[i] == '/')
-				off = i + 1;
-			i++;
-		}
-		in += off;
-		len -= off;
+	if (i == prefix_len)
+		return in;
 
-		while (i < prefix_len) {
-			if (prefix[i] == '/')
-				strbuf_addstr(out, "../");
-			i++;
-		}
+	strbuf_reset(sb);
+	strbuf_grow(sb, len);
+
+	while (i < prefix_len) {
+		if (prefix[i] == '/')
+			strbuf_addstr(sb, "../");
+		i++;
 	}

By the way, I noticed that we rely on the fact that a non-empty
prefix ends with '/'. Is that ok?

-	strbuf_add(out, in, len);
+	strbuf_add(sb, in, len);
 
-	return out->buf;
+	return sb->buf;
 }