/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

//

// Copyright (c) 2006 Georgia Tech Research Corporation

//

// This program is free software; you can redistribute it and/or modify

// it under the terms of the GNU General Public License version 2 as

// published by the Free Software Foundation;

//

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with this program; if not, write to the Free Software

// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

//

// Author: Rajib Bhattacharjea<raj.b@gatech.edu>

//

// Ported from:

// Georgia Tech Network Simulator - Manage 32 bit unsigned sequence numbers

// George F. Riley.  Georgia Tech, Spring 2002

// Class to manage arithmetic operations on sequence numbers (mod 2^32)

#include "sequence-number.h"

bool operator< (const SequenceNumber l, const SequenceNumber r) 

{ // Account for 32 bit rollover

  if (l.seq > 0xc0000000 && r.seq < 0x40000000) return true; // Rollover

  return l.seq < r.seq;

}

bool operator<= (const SequenceNumber l, const SequenceNumber r) 

{ // Account for 32 bit rollover

  if (l.seq > 0xc0000000 && r.seq < 0x40000000) return true; // Rollover

  return l.seq <= r.seq;

}

bool operator> (const SequenceNumber l, const SequenceNumber r) 

{ // Account for 32 bit rollover

  if (l.seq > 0xc0000000 && r.seq < 0x40000000) return false; // Rollover

  return l.seq > r.seq;

}

bool operator>= (const SequenceNumber l, const SequenceNumber r) 

{ // Account for 32 bit rollover

  if (l.seq > 0xc0000000 && r.seq < 0x40000000) return false; // Rollover

  return l.seq >= r.seq;

}

// Non-Member Arithmetic operators

SequenceNumber  operator+ (const SequenceNumber l, const SequenceNumber r)

{

  return SequenceNumber (l.seq + r.seq);

}

SequenceNumber operator- (const SequenceNumber l, const SequenceNumber r)

{ // This assumes l is always bigger than r (allows for rollover)

  if (l.seq >= r.seq) return SequenceNumber (l.seq-r.seq);

  return SequenceNumber ((MAX_SEQ - r.seq) + l.seq + 1);  // Adjust for rollover

}