From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Thu, 11 Mar 2021 23:27:30 +0000 (+0200)
Subject: lib: Optimize str_append_tabescaped()
X-Git-Tag: 2.3.17~99
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ea636c55e4bea1785e5178b41c48c634eba8bc6d;p=thirdparty%2Fdovecot%2Fcore.git

lib: Optimize str_append_tabescaped()

Avoid calling strlen() and replace for-loop with strcspn().
---

diff --git a/src/lib/strescape.c b/src/lib/strescape.c
index 73489cad84..99482a5700 100644
--- a/src/lib/strescape.c
+++ b/src/lib/strescape.c
@@ -135,7 +135,35 @@ void str_append_tabescaped_n(string_t *dest, const unsigned char *src, size_t sr
 
 void str_append_tabescaped(string_t *dest, const char *src)
 {
-	str_append_tabescaped_n(dest, (const unsigned char*)src, strlen(src));
+	size_t pos, prev_pos = 0;
+	char esc[2] = { '\001', '\0' };
+
+	for (;;) {
+		pos = prev_pos + strcspn(src + prev_pos, "\001\t\r\n");
+		str_append_data(dest, src + prev_pos, pos - prev_pos);
+		prev_pos = pos + 1;
+
+		switch (src[pos]) {
+		case '\000':
+			/* end of src string reached */
+			return;
+		case '\001':
+			esc[1] = '1';
+			break;
+		case '\t':
+			esc[1] = 't';
+			break;
+		case '\r':
+			esc[1] = 'r';
+			break;
+		case '\n':
+			esc[1] = 'n';
+			break;
+		default:
+			i_unreached();
+		}
+		str_append_data(dest, esc, 2);
+	}
 }