boost/progress.hpp

   1 //  boost progress.hpp header file  ------------------------------------------//
   2
   3 //  Copyright Beman Dawes 1994-99.  Distributed under the Boost
   4 //  Software License, Version 1.0. (See accompanying file
   5 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  See http://www.boost.org/libs/timer for documentation.
   8
   9 //  Revision History
  10 //   1 Dec 01  Add leading progress display strings (suggested by Toon Knapen)
  11 //  20 May 01  Introduce several static_casts<> to eliminate warning messages
  12 //             (Fixed by Beman, reported by Herve Bronnimann)
  13 //  12 Jan 01  Change to inline implementation to allow use without library
  14 //             builds. See docs for more rationale. (Beman Dawes)
  15 //  22 Jul 99  Name changed to .hpp
  16 //  16 Jul 99  Second beta
  17 //   6 Jul 99  Initial boost version
  18
  19 #ifndef BOOST_PROGRESS_HPP
  20 #define BOOST_PROGRESS_HPP
  21
  22 #include <boost/timer.hpp>
  23 #include <boost/utility.hpp>  // for noncopyable
  24 #include <boost/cstdint.hpp>  // for uintmax_t
  25 #include <iostream>           // for ostream, cout, etc
  26 #include <string>             // for string
  27
  28 namespace boost {
  29
  30 //  progress_timer  ----------------------------------------------------------//
  31
  32 //  A progress_timer behaves like a timer except that the destructor displays
  33 //  an elapsed time message at an appropriate place in an appropriate form.
  34
  35 class progress_timer : public timer, private noncopyable
  36 {
  37
  38  public:
  39   explicit progress_timer( std::ostream & os = std::cout )
  40      // os is hint; implementation may ignore, particularly in embedded systems
  41      : m_os(os) {}
  42   ~progress_timer()
  43   {
  44   //  A) Throwing an exception from a destructor is a Bad Thing.
  45   //  B) The progress_timer destructor does output which may throw.
  46   //  C) A progress_timer is usually not critical to the application.
  47   //  Therefore, wrap the I/O in a try block, catch and ignore all exceptions.
  48     try
  49     {
  50       // use istream instead of ios_base to workaround GNU problem (Greg Chicares)
  51       std::istream::fmtflags old_flags = m_os.setf( std::istream::fixed,
  52                                                    std::istream::floatfield );
  53       std::streamsize old_prec = m_os.precision( 2 );
  54       m_os << elapsed() << " s\n" // "s" is System International d'Unites std
  55                         << std::endl;
  56       m_os.flags( old_flags );
  57       m_os.precision( old_prec );
  58     }
  59
  60     catch (...) {} // eat any exceptions
  61   } // ~progress_timer
  62
  63  private:
  64   std::ostream & m_os;
  65 };
  66
  67
  68 //  progress_display  --------------------------------------------------------//
  69
  70 //  progress_display displays an appropriate indication of
  71 //  progress at an appropriate place in an appropriate form.
  72
  73 // NOTE: (Jan 12, 2001) Tried to change unsigned long to boost::uintmax_t, but
  74 // found some compilers couldn't handle the required conversion to double.
  75 // Reverted to unsigned long until the compilers catch up.
  76
  77 class progress_display : private noncopyable
  78 {
  79  public:
  80   explicit progress_display( unsigned long expected_count_,
  81                              std::ostream & os = std::cout,
  82                              const std::string & s1 = "\n", //leading strings
  83                              const std::string & s2 = "",
  84                              const std::string & s3 = "" )
  85    // os is hint; implementation may ignore, particularly in embedded systems
  86    : m_os(os), m_s1(s1), m_s2(s2), m_s3(s3) { restart(expected_count_); }
  87
  88   void           restart( unsigned long expected_count_ )
  89   //  Effects: display appropriate scale
  90   //  Postconditions: count()==0, expected_count()==expected_count_
  91   {
  92     _count = _next_tic_count = _tic = 0;
  93     _expected_count = expected_count_;
  94
  95     m_os << m_s1 << "0%   10   20   30   40   50   60   70   80   90   100%\n"
  96          << m_s2 << "|----|----|----|----|----|----|----|----|----|----|"
  97          << std::endl  // endl implies flush, which ensures display
  98          << m_s3;
  99     if ( !_expected_count ) _expected_count = 1;  // prevent divide by zero
 100   } // restart
 101
 102   unsigned long  operator+=( unsigned long increment )
 103   //  Effects: Display appropriate progress tic if needed.
 104   //  Postconditions: count()== original count() + increment
 105   //  Returns: count().
 106   {
 107     if ( (_count += increment) >= _next_tic_count ) { display_tic(); }
 108     return _count;
 109   }
 110
 111   unsigned long  operator++()           { return operator+=( 1 ); }
 112   unsigned long  count() const          { return _count; }
 113   unsigned long  expected_count() const { return _expected_count; }
 114
 115   private:
 116   std::ostream &     m_os;  // may not be present in all imps
 117   const std::string  m_s1;  // string is more general, safer than
 118   const std::string  m_s2;  //  const char *, and efficiency or size are
 119   const std::string  m_s3;  //  not issues
 120
 121   unsigned long _count, _expected_count, _next_tic_count;
 122   unsigned int  _tic;
 123   void display_tic()
 124   {
 125     // use of floating point ensures that both large and small counts
 126     // work correctly.  static_cast<>() is also used several places
 127     // to suppress spurious compiler warnings.
 128     unsigned int tics_needed =
 129       static_cast<unsigned int>(
 130         (static_cast<double>(_count)/_expected_count)*50.0 );
 131     do { m_os << '*' << std::flush; } while ( ++_tic < tics_needed );
 132     _next_tic_count =
 133       static_cast<unsigned long>((_tic/50.0)*_expected_count);
 134     if ( _count == _expected_count ) {
 135       if ( _tic < 51 ) m_os << '*';
 136       m_os << std::endl;
 137       }
 138   } // display_tic
 139 };
 140
 141 } // namespace boost
 142
 143 #endif  // BOOST_PROGRESS_HPP