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libs/spirit/optimization/karma/format_performance.cpp

//   Copyright (c) 2002-2010 Hartmut Kaiser
//   Copyright (c) 2002-2010 Joel de Guzman
// 
//   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)

#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/karma.hpp>
#include <boost/format.hpp>

#include <iostream>

#include "../high_resolution_timer.hpp"

#define NUMITERATIONS 1000000

///////////////////////////////////////////////////////////////////////////////
//  policy for real_generator, which forces to output trailing zeros in the 
//  fractional part
//[karma_format_performance_definitions
template <typename T>
struct double3_policy : boost::spirit::karma::real_policies<T>   
{
    //  we want to generate up to 3 fractional digits
    static unsigned int precision(T) { return 3; }
};

typedef boost::spirit::karma::real_generator<double, double3_policy<double> > 
    double3_type;
double3_type const double3 = double3_type();
//]

void format_performance_karma()
{
    using boost::spirit::karma::left_align;
    using boost::spirit::karma::generate;

    //[karma_format_performance_plain
    char buffer[256];
    //<-
    util::high_resolution_timer t;
    //->
    for (int i = 0; i < NUMITERATIONS; ++i) {
        char *p = buffer;
        generate(p
          , '[' << left_align(14)[double3] << left_align(14)[double3] << ']'
          , 12345.12345, 12345.12345);
        *p = '\0';
    }
    //]

    std::cout << "karma:\t\t" << t.elapsed() << std::endl;
//     std::cout << buffer << std::endl;
}

void format_performance_rule()
{
    using boost::spirit::karma::left_align;
    using boost::spirit::karma::generate;

    typedef boost::fusion::vector<double, double> rtype;
    boost::spirit::karma::rule<char*, rtype()> r;

    //[karma_format_performance_rule
    char buffer[256];
    r %= '[' << left_align(14)[double3] << left_align(14)[double3] << ']';
    //<-
    util::high_resolution_timer t;
    //->
    for (int i = 0; i < NUMITERATIONS; ++i) {
        char *p = buffer;
        generate(p, r, 12345.12345, 12345.12345);
        *p = '\0';
    }
    //]

    std::cout << "karma (rule):\t" << t.elapsed() << std::endl;
//     std::cout << buffer << std::endl;
}

void format_performance_string()
{
    using boost::spirit::karma::left_align;
    using boost::spirit::karma::generate;

    //[karma_format_performance_string
    std::string generated;
    std::back_insert_iterator<std::string> sink(generated);
    //<-
    util::high_resolution_timer t;
    //->
    for (int i = 0; i < NUMITERATIONS; ++i) {
        generated.clear();
        generate(sink
          , '[' << left_align(14)[double3] << left_align(14)[double3] << ']'
          , 12345.12345, 12345.12345);
    }
    //]

    std::cout << "karma (string):\t" << t.elapsed() << std::endl;
//     std::cout << generated << std::endl;
}

// Boost.Format  
void format_performance_boost_format()
{
    //[karma_format_performance_format
    std::string generated;
    boost::format outformat("[%-14.3f%-14.3f]");
    //<-
    util::high_resolution_timer t;
    //->
    for (int i = 0; i < NUMITERATIONS; ++i)
        generated = boost::str(outformat % 12345.12345 % 12345.12345);
    //]

    std::cout << "format:\t\t" << t.elapsed() << std::endl;
//     std::cout << strm.str() << std::endl;
}

void format_performance_sprintf()
{
    util::high_resolution_timer t;

    //[karma_format_performance_printf
    char buffer[256];
    for (int i = 0; i < NUMITERATIONS; ++i) {
        sprintf(buffer, "[%-14.3f%-14.3f]", 12345.12345, 12345.12345);
    }
    //]

    std::cout << "sprintf:\t" << t.elapsed() << std::endl;
//     std::cout << buffer << std::endl;
}

void format_performance_iostreams()
{
    //[karma_format_performance_iostreams
    std::stringstream strm;
    //<-
    util::high_resolution_timer t;
    //->
    for (int i = 0; i < NUMITERATIONS; ++i) {
        strm.str("");
        strm << '[' 
          << std::setiosflags(std::ios::fixed)
          << std::left
          << std::setprecision(3)
          << std::setw(14)
          << 12345.12345
          << std::setw(14)
          << 12345.12345
          << ']';
    }
    //]

    std::cout << "iostreams:\t" << t.elapsed() << std::endl;
//     std::cout << strm.str() << std::endl;
}

///////////////////////////////////////////////////////////////////////////////
int main()
{
    format_performance_sprintf();
    format_performance_iostreams();
    format_performance_boost_format();
    format_performance_karma();
    format_performance_string();
    format_performance_rule();
    return 0;
}