- byte [] bytes = Enc.GetBytes (s);
- return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, bytes.Length));
+ bool needEncode = false;
+ int len = s.Length;
+ for (int i = 0; i < len; i++) {
+ char c = s [i];
+ if ((c < '0') || (c < 'A' && c > '9') || (c > 'Z' && c < 'a') || (c > 'z')) {
+ if (NotEncoded (c))
+ continue;
+
+ needEncode = true;
+ break;
+ }
+ }
+
+ if (!needEncode)
+ return s;
+
+ // avoided GetByteCount call
+ byte [] bytes = new byte[Enc.GetMaxByteCount(s.Length)];
+ int realLen = Enc.GetBytes (s, 0, s.Length, bytes, 0);
+ return Encoding.ASCII.GetString (UrlEncodeToBytes (bytes, 0, realLen));