vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/progress.hpp

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5.6 KiB
C++

// 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/noncopyable.hpp>
#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
: timer(), noncopyable(), 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'Unites 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
: noncopyable(), 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)
/ static_cast<double>(_expected_count)) * 50.0);
do { m_os << '*' << std::flush; } while ( ++_tic < tics_needed );
_next_tic_count =
static_cast<unsigned long>((_tic/50.0) * static_cast<double>(_expected_count));
if ( _count == _expected_count ) {
if ( _tic < 51 ) m_os << '*';
m_os << std::endl;
}
} // display_tic
};
} // namespace boost
#endif // BOOST_PROGRESS_HPP