Function findLastSubmessage

dds/DCPS/security/CryptoBuiltInImpl.cpp:1331–1351

Precondition: the bytes of 'plaintext' are a sequence of RTPS Submessages Returns the index of the final Submessage in the sequence, or 0 if this can't be determined.

  // Precondition: the bytes of 'plaintext' are a sequence of RTPS Submessages
  // Returns the index of the final Submessage in the sequence, or 0 if this can't be determined.
  unsigned int findLastSubmessage(const DDS::OctetSeq& plaintext)
  {
    RTPS::MessageParser parser(plaintext);
    const char* const start = parser.current();

    while (parser.remaining() >= RTPS::SMHDR_SZ) {
      const unsigned int sm_start = static_cast<unsigned int>(parser.current() - start);

      if (!parser.parseSubmessageHeader()) {
        return 0;
      }

      if (!parser.hasNextSubmessage()) {
        return sm_start;
      }

      parser.skipToNextSubmessage();
    }

    return 0;
  }

  unsigned int roundUp(unsigned int length, unsigned int alignment)
  {