SendHL7Message may never return

[alaa9jo]

Case: Let's say the destination service may not reply with any bytes if the message you send has incorrect values set in segments; it simply ignore the message you send and ReadByte() return -1

This is a snippet code of function SendHL7Message:

StringBuilder sb = new StringBuilder();
bool messageComplete = false;
while (!messageComplete) {
  int b = streamToUse.ReadByte();
  if (b != -1)
    sb.Append((char) b);

  messageComplete = MLLP.ValidateMLLPMessage(sb);
}

streamToUse.ReadByte() will always return -1 in that case, and function MLLP.ValidateMLLPMessage will always return false since sb.length is not > 3, look at below code:

public static bool ValidateMLLPMessage(StringBuilder sb) {
  bool result = false;

  if (sb.Length > 3) {
    if (((int) sb[0] == MLLP_START_CHARACTER)) {
      if (((int) sb[sb.Length - 2] == MLLP_FIRST_END_CHARACTER) && ((int) sb[sb.Length - 1] == MLLP_LAST_END_CHARACTER))
        result = true;
    }
  }

  return result;
}

What happens is that the code will get stuck in infinite loop, SendHL7Message will never return and the caller will get stuck.

There should be a way to break from this loop, maybe return a custom timeout error if streamToUse.ReadByte() repeatedly returns 0 bytes for some time?

[dib0]

Thanks! I've added an optional timeout parameter. It will throw a TimeoutException on timeout. This will be included in the next release