00001 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ 00002 // 00003 // Copyright (c) 2006 Georgia Tech Research Corporation 00004 // 00005 // This program is free software; you can redistribute it and/or modify 00006 // it under the terms of the GNU General Public License version 2 as 00007 // published by the Free Software Foundation; 00008 // 00009 // This program is distributed in the hope that it will be useful, 00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00012 // GNU General Public License for more details. 00013 // 00014 // You should have received a copy of the GNU General Public License 00015 // along with this program; if not, write to the Free Software 00016 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00017 // 00018 // Author: Rajib Bhattacharjea<raj.b@gatech.edu> 00019 // 00020 00021 00022 // Ported from: 00023 // Georgia Tech Network Simulator - Manage 32 bit unsigned sequence numbers 00024 // George F. Riley. Georgia Tech, Spring 2002 00025 00026 // Class to manage arithmetic operations on sequence numbers (mod 2^32) 00027 00028 #include "sequence-number.h" 00029 00030 bool operator< (const SequenceNumber l, const SequenceNumber r) 00031 { // Account for 32 bit rollover 00032 if (l.seq > 0xc0000000 && r.seq < 0x40000000) return true; // Rollover 00033 return l.seq < r.seq; 00034 } 00035 00036 bool operator<= (const SequenceNumber l, const SequenceNumber r) 00037 { // Account for 32 bit rollover 00038 if (l.seq > 0xc0000000 && r.seq < 0x40000000) return true; // Rollover 00039 return l.seq <= r.seq; 00040 } 00041 00042 bool operator> (const SequenceNumber l, const SequenceNumber r) 00043 { // Account for 32 bit rollover 00044 if (l.seq > 0xc0000000 && r.seq < 0x40000000) return false; // Rollover 00045 return l.seq > r.seq; 00046 } 00047 00048 bool operator>= (const SequenceNumber l, const SequenceNumber r) 00049 { // Account for 32 bit rollover 00050 if (l.seq > 0xc0000000 && r.seq < 0x40000000) return false; // Rollover 00051 return l.seq >= r.seq; 00052 } 00053 00054 // Non-Member Arithmetic operators 00055 SequenceNumber operator+ (const SequenceNumber l, const SequenceNumber r) 00056 { 00057 return SequenceNumber (l.seq + r.seq); 00058 } 00059 00060 SequenceNumber operator- (const SequenceNumber l, const SequenceNumber r) 00061 { // This assumes l is always bigger than r (allows for rollover) 00062 if (l.seq >= r.seq) return SequenceNumber (l.seq-r.seq); 00063 return SequenceNumber ((MAX_SEQ - r.seq) + l.seq + 1); // Adjust for rollover 00064 } 00065