strfmt.h

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#ifndef __strfmt_h__
#define __strfmt_h__

#include "asserts.h"
#include "types.h"
#include "estring.h"
#include "rmath.h"

/** Given an integral number, return a string with the number formatted as a
        human-readable machine-type size.  (Ex: 10240 becomes "10Kb") */
template<class T>
std::string size_to_string(
        T a_t,
        const std::string& a_base_size_unit = "b",
        uint16 a_width = 8,
        uint16 a_precision = 1, 
        uint16 a_kilo = 1024
        )
{
        enum {
                ones = 0,
                kilo,
                mega,
                giga,
                tera,
                peta,
                exa,
                zetta,
                yotta
        };
        const char* units[] = {
                " ",
                "K",
                "M",
                "G",
                "T",
                "P",
                "E",
                "Z",
                "Y"
        };
        std::string es;
        int resolution = ones;
        std::string str;
        safe_num<T> quotient = a_t;
        safe_num<T> remainder = 0;
        safe_num<T> rmul = 10;
        safe_num<T> tmp;

        TRY_nomem(es = "Could not generate size-string: \"");
        TRY_nomem(es += estring(a_t));
        TRY_nomem(es += "\"");

        for (tmp = 1; tmp < a_precision; ++tmp) {
                rmul *= 10;
        }
        while ((quotient >= a_kilo) && (resolution < yotta)) {
                TRY(
                        tmp = quotient;
                        tmp *= rmul;
                        //
                        // *** NOT SURE ABOUT THIS:
                        // This involves a conversion from uint16 to T
                        // for safe_num<T>(a_kilo)
                        //
                        remainder = (tmp / safe_num<T>(a_kilo)) % rmul;
                        quotient /= a_kilo;
                        ,es);
                        resolution++;
        }

        if (resolution > ones) {
                TRY(
                        str += estring(quotient.value()).fmt_str(
                                a_width-(a_precision+1)-2,estring::right,' ','x'),
                        es);
                TRY_nomem(str += ".");
                TRY(
                        str += estring(remainder.value()).fmt_str(a_precision,estring::right,'0','x'),
                        es);
        }
        else {
                TRY(
                        str += estring(quotient.value()).fmt_str(a_width-2,estring::right,' ','x'),
                        es);
        }
        TRY_nomem(str += units[resolution]);
        TRY_nomem(str += a_base_size_unit);

        return(str);
}

/** Given an integral number, return a string with the number formatted in a
 generic, human-readable format.  (Ex: 10240 becomes "10,240") */
template<class T>
std::string num_to_string(T a_t, uint16 a_width = 0)
{
        std::string es;
        std::string tstr;
        estring str;
        std::string::size_type n;
        
        TRY_nomem(tstr = estring(a_t));
        TRY_nomem(es = "Could not generate num-string: \"");
        TRY_nomem(es += tstr);
        TRY_nomem(es += "\"");

        if (tstr.size() == 0) {
                return(tstr);
        }
        
        n = tstr.size();
        while (n > 0) {
                if (str.size() > 0) {
                        TRY_nomem(str = "," + str);
                }
                str = tstr[(n--)-1] + str; if (n == 0) break;
                str = tstr[(n--)-1] + str; if (n == 0) break;
                str = tstr[(n--)-1] + str;
        }

        if (a_width == 0) {
                return(str);
        }
        str.width(a_width);
        str.align(estring::right);
        TRY_nomem(tstr = str.fmt_str());

        return(tstr);
}

/** Given an integral number, return a string with the number formated as a
 number of machine-type size per second.  (Ex: 10240 becomes "10Kb/s") */
template<class T>
std::string throughput_to_string(
        T a_t,
        const std::string& a_base_size_unit = "b",
        const std::string& a_base_time_unit = "s",
        uint16 a_width = 10,
        uint16 a_precision = 1,
        uint16 a_kilo = 1024
        )
{
        std::string str;

        TRY_nomem(
                str = size_to_string(a_t, a_base_size_unit, a_width-2, a_precision, a_kilo)
                );
        TRY_nomem(str += "/");
        TRY_nomem(str += a_base_time_unit);

        return(str);
}

/** Given a count complete and a count total, calculate a percentage */
template<typename T>
std::string percent_string(const T& a_complete, const T& a_total)
{
        safe_num<double> percent;
        estring es;
        estring estr;
        std::string str;

        es = "Could not calculate percentage";
        if (a_complete == static_cast<T>(0)) {
                percent = static_cast<T>(0);
        }
        else if (a_total == static_cast<T>(0)) {
                TRY_nomem(str = "??.?%");
                return(str);
        }
        else {
                TRY (
                        percent = static_cast<double>(a_complete);
                        percent *= 100;
                        percent /= static_cast<double>(a_total);
                        ,es);
        }
        estr.width(5);
        estr.align(estring::right);
        estr.fillchar(' ');
        estr.precision(1);
        estr = percent.value();
        TRY_nomem(str = estr.fmt_str());
        TRY_nomem(str += "%");

        return(str);
}

#endif