//  boost progress.hpp header file  ------------------------------------------//



//  Copyright Beman Dawes 1994-99.  Distributed under the Boost

//  Software License, Version 1.0. (See accompanying file

//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)



//  See http://www.boost.org/libs/timer for documentation.



//  Revision History

//   1 Dec 01  Add leading progress display strings (suggested by Toon Knapen)

//  20 May 01  Introduce several static_casts<> to eliminate warning messages

//             (Fixed by Beman, reported by Herve Bronnimann)

//  12 Jan 01  Change to inline implementation to allow use without library

//             builds. See docs for more rationale. (Beman Dawes) 

//  22 Jul 99  Name changed to .hpp

//  16 Jul 99  Second beta

//   6 Jul 99  Initial boost version



#ifndef BOOST_PROGRESS_HPP

#define BOOST_PROGRESS_HPP



#include <boost/timer.hpp>

#include <boost/utility.hpp>  // for noncopyable

#include <boost/cstdint.hpp>  // for uintmax_t

#include <iostream>           // for ostream, cout, etc

#include <string>             // for string



namespace boost {



//  progress_timer  ----------------------------------------------------------//



//  A progress_timer behaves like a timer except that the destructor displays

//  an elapsed time message at an appropriate place in an appropriate form.



class progress_timer : public timer, private noncopyable

{

  

 public:

  explicit progress_timer( std::ostream & os = std::cout )

     // os is hint; implementation may ignore, particularly in embedded systems

     : m_os(os) {}

  ~progress_timer()

  {

  //  A) Throwing an exception from a destructor is a Bad Thing.

  //  B) The progress_timer destructor does output which may throw.

  //  C) A progress_timer is usually not critical to the application.

  //  Therefore, wrap the I/O in a try block, catch and ignore all exceptions.

    try

    {

      // use istream instead of ios_base to workaround GNU problem (Greg Chicares)

      std::istream::fmtflags old_flags = m_os.setf( std::istream::fixed,

                                                   std::istream::floatfield );

      std::streamsize old_prec = m_os.precision( 2 );

      m_os << elapsed() << " s\n" // "s" is System International d'Unités std

                        << std::endl;

      m_os.flags( old_flags );

      m_os.precision( old_prec );

    }



    catch (...) {} // eat any exceptions

  } // ~progress_timer



 private:

  std::ostream & m_os;

};





//  progress_display  --------------------------------------------------------//



//  progress_display displays an appropriate indication of 

//  progress at an appropriate place in an appropriate form.



// NOTE: (Jan 12, 2001) Tried to change unsigned long to boost::uintmax_t, but

// found some compilers couldn't handle the required conversion to double.

// Reverted to unsigned long until the compilers catch up. 



class progress_display : private noncopyable

{

 public:

  explicit progress_display( unsigned long expected_count,

                             std::ostream & os = std::cout,

                             const std::string & s1 = "\n", //leading strings

                             const std::string & s2 = "",

                             const std::string & s3 = "" )

   // os is hint; implementation may ignore, particularly in embedded systems

   : m_os(os), m_s1(s1), m_s2(s2), m_s3(s3) { restart(expected_count); }



  void           restart( unsigned long expected_count )

  //  Effects: display appropriate scale

  //  Postconditions: count()==0, expected_count()==expected_count

  {

    _count = _next_tic_count = _tic = 0;

    _expected_count = expected_count;



    m_os << m_s1 << "0%   10   20   30   40   50   60   70   80   90   100%\n"

         << m_s2 << "|----|----|----|----|----|----|----|----|----|----|"

         << std::endl  // endl implies flush, which ensures display

         << m_s3;

    if ( !_expected_count ) _expected_count = 1;  // prevent divide by zero

  } // restart



  unsigned long  operator+=( unsigned long increment )

  //  Effects: Display appropriate progress tic if needed.

  //  Postconditions: count()== original count() + increment

  //  Returns: count().

  {

    if ( (_count += increment) >= _next_tic_count ) { display_tic(); }

    return _count;

  }



  unsigned long  operator++()           { return operator+=( 1 ); }

  unsigned long  count() const          { return _count; }

  unsigned long  expected_count() const { return _expected_count; }



  private:

  std::ostream &     m_os;  // may not be present in all imps

  const std::string  m_s1;  // string is more general, safer than 

  const std::string  m_s2;  //  const char *, and efficiency or size are

  const std::string  m_s3;  //  not issues



  unsigned long _count, _expected_count, _next_tic_count;

  unsigned int  _tic;

  void display_tic()

  {

    // use of floating point ensures that both large and small counts

    // work correctly.  static_cast<>() is also used several places

    // to suppress spurious compiler warnings. 

    unsigned int tics_needed =

      static_cast<unsigned int>(

        (static_cast<double>(_count)/_expected_count)*50.0 );

    do { m_os << '*' << std::flush; } while ( ++_tic < tics_needed );

    _next_tic_count = 

      static_cast<unsigned long>((_tic/50.0)*_expected_count);

    if ( _count == _expected_count ) {

      if ( _tic < 51 ) m_os << '*';

      m_os << std::endl;

      }

  } // display_tic

};



} // namespace boost



#endif  // BOOST_PROGRESS_HPP

