Need clarification in olsr-header.h file

[Doaa]

Hi all,

I am studying the OlSR protocol, There is a part of the code that I did not understand in olsr-header.h file

Hello& GetHello ()

592  {

593  if (m_messageType == 0)

594  {

595  m_messageType = HELLO_MESSAGE;

596  }

597  else

598  {

599  NS_ASSERT (m_messageType == HELLO_MESSAGE);

600  }

601  return m_message.hello;

602  }

How come if m_messageType == 0, then m_messageType is a hello msg?

or Is this have another meaning?

Thanks in advance

[Tommaso Pecorella]

Hi,

it's a (questionable) design choice. I wouldn't have done in this way, but it works. As a consequence, it's just a choice.

All the OLSR headers are the very same header class. The m_messageType variable decides what header kind is for real.

When you create a header, its type is zero. When you "use" it for the first time as a particular header its type is written into m_messageType and never changed again (quite logical).

As I said, I wouldn't have done this, but it works.

Cheers,

T.

[Doaa]

Thanks  Tommaso  for the clarification!