[SOLVED] date() / time() extension

[ulf.schroeter]

problem

 

When working with real-world data visualization time and date plays an important role. It is quite common to represent date/time values as compact UNIX timestamp int values. UNIGINE time() function allows gathering current timestamp value and date() function allows string formating of current date/time. Unfortunately there are no functions for conversion of UNIX timestamp int values to/from corresponding date/time strings. The makes both data date/time parsing and formating very complicated 

 

proposal

 

Addition of simple date/time string conversion to/from UNIX int timestamp e.g. by extending existing date/time functions for user-provisioning of explicit date string / timestamp int. Usage of default parameters should allow full code compatibility with existing script code.        

 

string  date( string format, int timestamp = -1 );
int     time( string datestring = 0 ); 

 

Required UNIGINE code change should be trivial, but would greatly simplify date/time handling via UNIGINE sript

[ulf.schroeter]

Just for illustration, some ugly temporary work-around code for timestamp conversion/date parsing. No solution for required conversion from timestamp to date/time string yet...

 

#ifndef __TIMESTAMP_H__
#define __TIMESTAMP_H__

///////////////////////////////////////////////////////////////////////////////

#define TIMESTAMP_MAX   2147483647      


/**
 * Timestamp utility
 */
namespace Timestamp
{
    int days_start_of_month[12] = ( 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 ) ;
    
    /**
     *  Calculate timestamp value from datetime string.
     *
     *  @param  datetime        datetime string in format 
     *
     *                          "dd/.mm/.yyyy hh:mm:ss" or
     *                          "yyyy/.mm/.dd hh:mm:ss"
     *                          "yy-mm-dd hh:mm:ss"
     *
     *  @return     seconds since 01.01.1970   (-1: error)
     */    
    int parseDate( string datetime )
    {
        string components[0];
        
        if( strsplit( datetime, "/.- :", components ) != 6 )
        {
            log.error( "Timestamp::parseDate() invalid date format '%s'\n", datetime ); return -1;
        }
        
        long year;
        long days;
        
        if( strlen( components[0] ) == 4 )
        {
            // yyyy/.mm/.dd hh:mm:ss
            year = long(components[0]);
            days = long(components[2]);
        }
        else if( strlen( components[2] ) == 4 ) 
        {
            // dd/.mm/.yyyy hh:mm:ss
            year = long(components[2]);
            days = long(components[0]);
        }
        else
        {
            // yy-mm-dd hh:mm:ss
            year = long(components[0]) + 2000;
            days = long(components[2]);
        }
        
        long month   = long( components[1] ); 
        long hours   = long( components[3] ); 
        long minutes = long( components[4] ); 
        long seconds = long( components[5] ); 
    
        return getTimestamp( year, month, days, hours, minutes, seconds );
    }

    /**
     *  Calculate timestamp value from date components.
     *
     *  @return     seconds since 01.01.1970    (-1: error)
     */    
    int getTimestamp( long year, long month, long days, long hours, long minutes, long seconds )
    {
        long timestamp;

        if( year    < 1970 || year    > 2038 )   { log.error("Timestamp::getTimestamp() invalid year %d\n",    year    ); return -1; }       
        if( month   < 1    || month   > 12   )   { log.error("Timestamp::getTimestamp() invalid month %d\n",   month   ); return -1; }       
        if( days    < 1    || days    > 31   )   { log.error("Timestamp::getTimestamp() invalid days %d\n",    days    ); return -1; }       
        if( hours   < 0    || hours   > 23   )   { log.error("Timestamp::getTimestamp() invalid hours %d\n",   hours   ); return -1; }       
        if( minutes < 0    || minutes > 59   )   { log.error("Timestamp::getTimestamp() invalid minutes %d\n", minutes ); return -1; }       
        if( seconds < 0    || seconds > 59   )   { log.error("Timestamp::getTimestamp() invalid seconds %d\n", seconds ); return -1; }       
        
        long years = year - 1970L;
        long leapyears = ((year-1L)-1968L)/4L - ((year-1L)-1900L)/100L + ((year-1L)-1600L)/400L;
 
        timestamp = seconds + 
                    60L * minutes + 
                    60L * 60L * hours +
                    (days_start_of_month[month-1L]+days-1L) * 60L * 60L * 24L +
                    (years * 365L + leapyears ) * 60L * 60L * 24L;
 
        if( (month > 2L) && ( year%4L == 0L && (year%100L != 0L || year%400L == 0L)) )
        {
            timestamp += 60L * 60L * 24L; /* +one day if leap year */
        }
        
        return int(timestamp);
    }
}

#endif /* __TIMESTAMP_H__ */

 

[frustum]

date() function will receive an optional time argument.

[ulf.schroeter]

thanks