/**
* Helper function that checks whether or not the data could be a SIP message. It is a very basic
* check but if it doesn't go through it definitely is not a SIP message.
*
* @param data
* @return
*/
public static boolean couldBeSipMessage(final Buffer data) throws IOException {
final byte a = data.getByte(0);
final byte b = data.getByte(1);
final byte c = data.getByte(2);
return a == 'S' && b == 'I' && c == 'P'
|| // response
a == 'I' && b == 'N' && c == 'V'
|| // INVITE
a == 'A' && b == 'C' && c == 'K'
|| // ACK
a == 'B' && b == 'Y' && c == 'E'
|| // BYE
a == 'O' && b == 'P' && c == 'T'
|| // OPTIONS
a == 'C' && b == 'A' && c == 'N'
|| // CANCEL
a == 'M' && b == 'E' && c == 'S'
|| // MESSAGE
a == 'R' && b == 'E' && c == 'G'
|| // REGISTER
a == 'I' && b == 'N' && c == 'F'
|| // INFO
a == 'P' && b == 'R' && c == 'A'
|| // PRACK
a == 'S' && b == 'U' && c == 'B'
|| // SUBSCRIBE
a == 'N' && b == 'O' && c == 'T'
|| // NOTIFY
a == 'U' && b == 'P' && c == 'D'
|| // UPDATE
a == 'R' && b == 'E' && c == 'F'
|| // REFER
a == 'P' && b == 'U' && c == 'B'; // PUBLISH
}
/**
* Convenience method for determining whether the method of this message is an ACK or not. Hence,
* this is NOT to the method to determine whether this is an ACK Request or not!
*
* @return true if the method of this message is a ACK, false otherwise.
* @throws SipParseException in case the method could not be parsed out of the underlying buffer.
*/
default boolean isAck() throws SipParseException {
final Buffer m = getMethod();
try {
return m.getByte(0) == 'A' && m.getByte(1) == 'C' && m.getByte(2) == 'K';
} catch (final IOException e) {
throw new SipParseException(
0, UNABLE_TO_PARSE_OUT_THE_METHOD_DUE_TO_UNDERLYING_IO_EXCEPTION, e);
}
}
/**
* Convenience method for determining whether the method of this message is a OPTIONS or not.
* Hence, this is NOT to the method to determine whether this is an OPTIONS Request or not!
*
* @return true if the method of this message is a OPTIONS, false otherwise.
* @throws SipParseException in case the method could not be parsed out of the underlying buffer.
*/
default boolean isOptions() throws SipParseException {
final Buffer m = getMethod();
try {
return m.getByte(0) == 'O'
&& m.getByte(1) == 'P'
&& m.getByte(2) == 'T'
&& m.getByte(3) == 'I'
&& m.getByte(4) == 'O'
&& m.getByte(5) == 'N'
&& m.getByte(6) == 'S';
} catch (final IOException e) {
throw new SipParseException(
0, UNABLE_TO_PARSE_OUT_THE_METHOD_DUE_TO_UNDERLYING_IO_EXCEPTION, e);
}
}