Measure time

[kartouss]

Hello i am new to this forum...can you help me solve this problem..
I have a function encrypt() which encrypts data from a file in 16 bytes till end of file which in turn calls other 4 functions...and i need to measure the time it encrypts the data consecutively for all the 4 functions till end of file...
I am fwding you the codes...Please help me out...

int Encrypt (word8 a[4][MAXBC], word8 rk[MAXROUNDS+1][4][MAXBC])
{	// Encryption of one blockl
		int r;
	sec_init();
	start_time = sec();
	AddRoundKey(a, rk[0]);
	stop_time = sec();
	Add1 = (stop_time - start_time);
	
	for ( r=1; r < ROUNDS; r++)
	{
		sec_init();
		start_time = sec();
			SubBytes (a,S);
		stop_time = sec();
		 sub1 = (stop_time - start_time);
		 
		sec_init();
		start_time = sec();
			ShiftRows(a);
		stop_time = sec();
		sft1 = (stop_time - start_time);
		
		sec_init();
		start_time = sec();			
			MixColumns(a);
		stop_time = sec();
		mix1 = (stop_time - start_time);
		
		sec_init();
		start_time = sec();
			AddRoundKey(a,rk[r]);
		stop_time = sec();
		Add2 = (stop_time - start_time);		
	}
	/* Last round is special; there is no MixColumns
	*/
	sec_init();
	start_time = sec();		
		SubBytes (a,S);
	stop_time = sec();
	sub2 = (stop_time - start_time);

	sec_init();
	start_time = sec();		
		ShiftRows(a);
	stop_time = sec();
	sft2 = (stop_time - start_time);

	sec_init();
	start_time = sec();		
		AddRoundKey(a,rk[ROUNDS]);
	stop_time = sec();
	Add3 = (stop_time - start_time);

	return 0;
}

// main function

// opens up a file plaintext.txt

char d;
	ifstream myfile1 ("Plaintext.txt");
	ofstream myfile3 ("Ciphertext.txt");
	
	myfile1.get(d);  //priming read

  while(!myfile1.eof())
{
	  for ( j=0; j<BC; j++)
	  for ( i=0; i < 4; i++)        
	  {
		  a[i][j] = d; // plaintext
		  //cout<<a[i][j]; // to chk how many plaintext is copied
		  myfile1.get(d);  //reads first element of next block
	  }

	  //sec_init();
		//start_time = sec();

		  Encrypt(a, rk);

		//stop_time = sec();
	    //enTime = (stop_time - start_time);
		//sum2+=enTime;

	  if (myfile3.is_open())
	  {
		  for(j=0; j< BC; j ++)
			  for ( i=0; i<4; i++)
				  myfile3<<a[i][j];
	  }   
	  else        
		cout << "Unable to open file";
  }					
	 
  	myfile3.close();
	myfile1.close();

// measure performance...

Add = Add1 + Add2*(ROUNDS-1) + Add3;
		sub = sub1*(ROUNDS-1) + sub2;
		sft = sft1*(ROUNDS-1) + sft2;
		mix = mix1*(ROUNDS-1);

		encryptTime = Add + sub + sft + mix;

The problem is that i am able to record the time for the first 16 bytes.. and i need to record the time for encrypting the data in the plaintext.txt file till eof()
please help me out..

[gpraghuram]

I dont know how the sec() function works
But my idea would be use time_t structure and use this logic

[code=c]
time_t start,end;
time(&start);
<your function call>
time(&end);

difftime(end,st art);//this gives the time difference in seconds

[/code]

Thanks
Raghuram