/////////////////////////////////////////////////////////////////////////////
// constr.cpp - demonstrate performance implications of object creation
//
// Jim Fawcett, CSE691 - SW Modeling & Analysis, Fall 2000
/////////////////////////////////////////////////////////////////////////////
// Platform: Dell XPS1000, Windows 2000 Professional, SP1

#include <string>
#include <iostream>
#include "..\timer.h"
using namespace std;

/////////////////////////////////////////////////////////////////////////////
// very small class

class empty { };

/////////////////////////////////////////////////////////////////////////////
// bigger class - holds an array of chars

class strArray { 
  
  public:
    strArray(char *s);

  private:
    char ch[100]; 
};

strArray::strArray(char *s) {

  for(int i=0; i<100 && s[i] != '\0'; i++)
    ch[i] = s[i];
}

/////////////////////////////////////////////////////////////////////////////
// a class holding several different data types (defined above etc)

class strMembers {

  public:
    strMembers(char *s);

  private:
    empty e;
    strArray sa;
    string ss;
};

strMembers::strMembers(char *s) : sa(s), ss(s) { }


//

/////////////////////////////////////////////////////////////////////////////
// build local empty object

void buildEmpty() { 

  static bool first = true;
  if(first) {
    cout << "\n  buildEmpty()";
    first = false;
  }
  empty e; 
}

/////////////////////////////////////////////////////////////////////////////
// build local strArray object

void buildStrArray() { 

  static bool first = true;
  if(first) {
    cout << "\n  buildStrArray()";
    first = false;
  }
  strArray sa("this is a string"); 
}

/////////////////////////////////////////////////////////////////////////////
// build local string object

void buildString() { 

  static bool first = true;
  if(first) {
    cout << "\n  buildString()";
    first = false;
  }
  string ss("this is a string"); 
}

/////////////////////////////////////////////////////////////////////////////
// build local strMembers object

void buildStrMembers() { 

  static bool first = true;
  if(first) {
    cout << "\n  buildStrMembers()";
    first = false;
  }
  strMembers sm("this is a string"); 
}

//

/////////////////////////////////////////////////////////////////////////////
// function to time function calls

template<class U> 
clock_t timeFunction(U(*pFunc)(), int N) {

  timer t;
  t.start();
  int i;
  for(i=0; i<N; i++)
    pFunc();
  t.stop();

  cout << "\n  time to call function " << N << " times = " 
       << t.elapsed() << " milliseconds" << endl;
  
  return t.elapsed();
}

/////////////////////////////////////////////////////////////////////////////
// test stub

void main() {

  cout << "\n  Demo Performance - constructing objects "
       << "\n =========================================\n";

  const int N = 500000;

  clock_t Ttest = timeFunction<void>(buildEmpty, N);
  
  Ttest = timeFunction<void>(buildStrArray, N);

  Ttest = timeFunction<void>(buildString, N);

  Ttest = timeFunction<void>(buildStrMembers, N);

  cout << "\n\n";
}