gf.cpp

传感器网络的可靠路由算法

#include "stdafx.h"
#include "Network.h"


//implement the GF functions 


/* global variables */
extern NODE_TYPE nodeT[4000];
extern NETWORK_TYPE net;

int bestNeighbor(int from,int dest);

void BuildGF(int root){

	int i;
	for( i = 0 ; i < net.NUM_NODES;i++){
	 int next = bestNeighbor(i,root);
	 if(next != INVALID_ID)
	   SetNextHop(i, root, next);
	 else
		 assert(false);
	}	
}

int bestNeighbor(int from,int dest) //gfX
{
 int i;

 bool found = false;
 double test = MAXCOST;
 int find;
 double currenttest;
 
 assert(from < net.NUM_NODES && dest < net.NUM_NODES);

 if(from == dest) return from;

 for (i=0;i<nodeT[from].neighbornum;i++) 
 {
   if ((unidirectional(from, nodeT[from].neighbor[i])==true))
	   continue;
   
   if(adistance(nodeT[from].neighbor[i],dest) > adistance(from,dest)) continue;


	     currenttest = adistance(nodeT[from].neighbor[i],dest);

         if (currenttest <test)
		 {		test = currenttest;
		        find = nodeT[from].neighbor[i];
		        found = true;
	     }   
 }

 if (found == false){
	 printf("node %d can not do greedy forward\n",from);
	 find = INVALID_ID;
	 assert(false);
 }
  // printf("%d->%d\n",from,find);

  return find;
}