CPP/common/utility.hpp

#ifndef _COMMON_UTILITY_HPP_
#define _COMMON_UTILITY_HPP_
#include <stdio.h>
#include <limits>
#include <cmath>
#include <filesystem>
#include <sys/statvfs.h>
#include <common/string.hpp>

class Utility
{
  public:
    static String formatNumber(size_t number,bool commas=true);
    static String formatNumber(long number,bool commas=true);
    static String formatNumber(double number,bool commas=true);
    static String formatNumber(double number,int places=2);
    static String formatCurrency(double number,int places=2);
    static bool fmod(double dividend,double divisor);
    static bool fmod(double dividend, double divisor,double epsilon);
    static String byteCountToString(double bytesTransferred, bool perSecond = true);
    static size_t getAvailableDiskSpace(const String &path);
  private:
    static String pad(String theString,char padChar,int toLength);
    static String addCommas(String& theString);
    Utility();
    ~Utility();
};

inline
Utility::Utility()
{
}

inline
Utility::~Utility()
{
}

inline
String Utility::byteCountToString(double bytesTransferred, bool perSecond)
{
  double roundedValue = std::round(bytesTransferred * 100.00)/100.00;
  String strBytesTransferrred;
  if(roundedValue >= 1E+15)
  {
    strBytesTransferrred = Utility::formatNumber(roundedValue/1E+15,2) + "Pb";
  }
  else if(roundedValue >= 1000000000000)
  {
    strBytesTransferrred = Utility::formatNumber(roundedValue/1000000000000,2) + "Tb";
  }
  else if(roundedValue >= 1073741824)
  {
    strBytesTransferrred = Utility::formatNumber(roundedValue/1073741824,2) + "Gb";
  }  
  else if(roundedValue >= 1000000)
  {
    strBytesTransferrred = Utility::formatNumber(roundedValue/1000000,2) + "Mb";
  }    
  else if(roundedValue >= 1000)
  {
    strBytesTransferrred = Utility::formatNumber(roundedValue/1000,2) + "Kb";
  } 
  else strBytesTransferrred =  Utility::formatNumber(roundedValue,2) + "B";   

  if(perSecond)strBytesTransferrred+="/s";

  return strBytesTransferrred;
}

inline
String Utility::formatNumber(size_t number, bool commas)
{
  String formattedString;
  String format="%lu";
  ::sprintf(formattedString.str(),format,number);
  return addCommas(formattedString);  
}

inline
String Utility::formatNumber(long number,bool commas)
{
  String formattedString;
  String format="%ld";
  ::sprintf(formattedString.str(),format,number);
  return addCommas(formattedString);
}

inline
String Utility::formatNumber(double number,int places)
{
  String numberString = formatCurrency(number, places);
  return numberString.substr(1);
}

inline
String Utility::formatCurrency(double number,int places)
{
  String formattedString;
  String format="%.";
  format+=String().fromInt(places);
  format+="f";
  ::sprintf(formattedString.str(),format,number);
  Block<String> items = formattedString.split('.');
  if(items[0].length()<=3)
  {
    if(2==items.size())
    {
      return "$"+items[0]+"."+items[1];
    }
    else
    {
      return "$"+items[0];
    }
  }
  String wholePart = addCommas(items[0]);
  if(2==items.size())
  {
    return "$"+wholePart+"."+items[1];
  }
  return "$"+wholePart;
}

inline
String Utility::addCommas(String& wholePart)
{
  String placesString;
  wholePart=wholePart.reverse();
  for(int index=0;index<wholePart.length();index++)
  {
    if(index>0 && 0==(index%3))placesString+=",";
    placesString+=wholePart.charAt(index);
  }
  placesString=placesString.reverse();
  return placesString;
}

inline
String Utility::pad(String theString,char padChar,int toLength)
{
  while(theString.length()<toLength)theString+=padChar;
  return theString;
}

inline
bool Utility::fmod(double dividend, double divisor,double epsilon) 
{
    if (divisor == 0.0)
    {
        return false; 
    }

    // Calculate the remainder
    double remainder = std::fmod(dividend, divisor);

    // Check if the absolute remainder is less than epsilon
    return std::fabs(remainder) < std::fabs(epsilon);
}

inline
bool Utility::fmod(double dividend, double divisor) 
{
    if (divisor == 0.0)
    {
        return false; 
    }

    // Define a small epsilon value for floating-point comparisons
    // Using machine epsilon for double is a common choice.
    const double epsilon = std::numeric_limits<double>::epsilon() * 100; // Multiplied for a slightly larger tolerance

    // Calculate the remainder
    double remainder = std::fmod(dividend, divisor);

    // Check if the absolute remainder is less than epsilon
    return std::fabs(remainder) < epsilon;
}

inline
size_t Utility::getAvailableDiskSpace(const String& path)
{
    std::filesystem::space_info si = std::filesystem::space(path.str());
    return si.available;
}
#endif