CWE-ou-minkata/Sources/Plasma/PubUtilLib/plUnifiedTime/plUnifiedTime.cpp

/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#include <float.h>
#include "plUnifiedTime.h"
#include "hsStlUtils.h"
#include "hsWindows.h"

#if HS_BUILD_FOR_UNIX
#include <sys/time.h>
#include <unistd.h>
#endif

#if HS_BUILD_FOR_WIN32
#include <sys/timeb.h>  // for timeb
#endif

#include "hsUtils.h"

#include <time.h>
#include "hsStream.h"


#if HS_BUILD_FOR_WIN32
//
// Converts Windows Time to Unified Time
//
#define MAGICWINDOWSOFFSET ((__int64)11644473600)  // magic number, taken from Python Source
//
hsBool plUnifiedTime::SetFromWinFileTime(const FILETIME ft)
{
    // FILETIME resolution seems to be 0.01 sec

    __int64 ff,ffsecs;
    ff = *(__int64*)(&ft);
    ffsecs = ff/(__int64)10000000;

    if (ffsecs >= MAGICWINDOWSOFFSET)  // make sure we won't end up negatice
    {
        fSecs = (UInt32)(ffsecs-MAGICWINDOWSOFFSET);
        fMicros = (UInt32)(ff % 10000000)/10;
        return true;
    }
    else
        // before the UNIX Epoch
        return false;
}

//
// Sets the unified time to the current UTC time
//
hsBool plUnifiedTime::SetToUTC()
{
    FILETIME ft;

    GetSystemTimeAsFileTime(&ft);   /* 100 ns blocks since 01-Jan-1641 */
    return SetFromWinFileTime(ft);
}
#elif HS_BUILD_FOR_UNIX

//
// Sets the unified time to the current UTC time
//
hsBool plUnifiedTime::SetToUTC()
{
    struct timeval tv;
    
    // get the secs and micros from Jan 1, 1970
    int ret = gettimeofday(&tv, nil);
    if (ret == 0)
    {
        fSecs = tv.tv_sec;
        fMicros = tv.tv_usec;
        return true;
    }
    else
    {
        return false;
    }
}
#else
#error "Unified Time Not Implemented on this platform!"
#endif


struct tm * plUnifiedTime::IGetTime(const time_t * timer) const
{
    struct tm * tm = nil;
    switch (fMode)
    {
    case kGmt:
        tm = gmtime(timer);
        break;
    default:
        tm = localtime(timer);
    }
    if ( tm )
        tm->tm_isdst = -1;
    return tm;
}

plUnifiedTime::plUnifiedTime(plUnifiedTime_CtorNow,int mode)
{
    SetMode((Mode)mode);
    ToCurrentTime();
}


plUnifiedTime::plUnifiedTime(const timeval & tv)
:   fMode(kGmt)
{
    *this = tv;
}

plUnifiedTime::plUnifiedTime(int mode, const struct tm & src)
:   fMode((Mode)mode)
{
    *this = src;
}

plUnifiedTime::plUnifiedTime(time_t t)
:   fMode(kGmt)
{
    *this = t;
}

plUnifiedTime::plUnifiedTime(unsigned long t)
:   fMode(kGmt)
{
    *this = t;
}

plUnifiedTime::plUnifiedTime(int year, int month, int day, int hour, int min, int sec, unsigned long usec, int dst)
:   fMode(kGmt)
{
    SetTime(year,month,day,hour,min,sec,usec,dst);
}

plUnifiedTime::plUnifiedTime(int mode, const char * buf, const char * fmt)
:   fMode((Mode)mode)
{
    FromString(buf,fmt);
}

plUnifiedTime::plUnifiedTime(const plUnifiedTime & src)
:   fMode(src.fMode)
{
    *this = src;
}

plUnifiedTime::plUnifiedTime(const plUnifiedTime * src)
:   fMode(src->fMode)
{
    *this = *src;
}

plUnifiedTime plUnifiedTime::GetCurrentTime(Mode mode)
{
    plUnifiedTime t;
    t.SetMode(mode);
    t.ToCurrentTime();
    return t;
}


const plUnifiedTime & plUnifiedTime::operator=(const plUnifiedTime & src)
{
    fSecs = src.fSecs;
    fMicros = src.fMicros;
    fMode = src.fMode;
    return *this;
}

const plUnifiedTime & plUnifiedTime::operator=(const plUnifiedTime * src)
{
    return operator=(*src);
}

const plUnifiedTime & plUnifiedTime::operator=(time_t src)
{
    fSecs = (UInt32)src;
    fMicros = 0;
    return *this;
}

const plUnifiedTime & plUnifiedTime::operator=(unsigned long src)
{
    fSecs = src;
    fMicros = 0;
    return *this;
}

const plUnifiedTime & plUnifiedTime::operator=(const struct timeval & src)
{
    fSecs = src.tv_sec;
    fMicros = src.tv_usec;
    return *this;
}

const plUnifiedTime & plUnifiedTime::operator=(const struct tm & src)
{
    struct tm atm = src;
    fSecs = (UInt32)mktime(&atm);   // this won't work after 2030 something, sorry
    return *this;
}

void plUnifiedTime::SetSecsDouble(double secs)
{
    hsAssert(secs>=0, "plUnifiedTime::SetSecsDouble negative time");
    double x,y;
    x = modf(secs,&y);
    fSecs = (UInt32)y;
    fMicros = (UInt32)(x*1000000);
}

void plUnifiedTime::FromMillis(UInt32 millis)
{
    fSecs = millis/1000;
    fMicros = 0;
}


void plUnifiedTime::ToCurrentTime()
{
    SetToUTC();
}

hsBool plUnifiedTime::SetGMTime(short year, short month, short day, short hour, short minute, short second, unsigned long usec, int dst)
{
    if( !SetTime( year, month, day, hour, minute, second, usec, dst ) )
        return false;

    fSecs -= IGetLocalTimeZoneOffset();
    fMode = kGmt;

    return true;
}

hsBool plUnifiedTime::SetTime(short year, short month, short day, short hour, short minute, short second, unsigned long usec, int dst)
{
    struct tm atm;
    atm.tm_sec = second;
    atm.tm_min = minute;
    atm.tm_hour = hour;
    atm.tm_mday = day;
    atm.tm_mon = month - 1;
    atm.tm_year = year - 1900;
    atm.tm_isdst = dst;
    fSecs = (UInt32)mktime(&atm);   // this won't work after 2030 something, sorry
    if (fSecs == -1)
        return false;
    if (fMicros >= 1000000)
        return false;
    fMicros = usec;
    fMode = kLocal;
    return true;
}

hsBool plUnifiedTime::GetTime(short &year, short &month, short &day, short &hour, short &minute, short &second) const
{
    struct tm* time = IGetTime((const time_t *)&fSecs);
    if (!time)
        return false;
    year = time->tm_year+1900;
    month = time->tm_mon+1;
    day = time->tm_mday;
    hour = time->tm_hour;
    minute = time->tm_min;
    second = time->tm_sec;
    return true;
}

const char* plUnifiedTime::Print() const
{
    static std::string s;
//  short year, month, day, hour, minute, second;
//  GetTime(year, month, day, hour, minute, second);
//
//  xtl::format(s,"yr %d mo %d day %d hour %d min %d sec %d",
//      year, month, day, hour, minute, second);

    s = Format("%c");
    return s.c_str();
}

const char* plUnifiedTime::PrintWMillis() const
{
    static std::string s;
    xtl::format(s,"%s,s:%d,ms:%d",
        Print(), GetSecs(), GetMillis() );
    return s.c_str();
}

struct tm * plUnifiedTime::GetTm(struct tm * ptm) const
{
    if (ptm != nil)
    {
        *ptm = *IGetTime((const time_t *)&fSecs);
        return ptm;
    }
    else
        return IGetTime((const time_t *)&fSecs);
}

int plUnifiedTime::GetYear() const
{ 
    return GetTm() ? GetTm()->tm_year + 1900 : 0; 
}
int plUnifiedTime::GetMonth() const
{ 
    return GetTm() ? GetTm()->tm_mon + 1 : 0; 
}
int plUnifiedTime::GetDay() const
{ 
    return GetTm() ? GetTm()->tm_mday : 0; 
}
int plUnifiedTime::GetHour() const
{ 
    return GetTm() ? GetTm()->tm_hour : 0; 
}
int plUnifiedTime::GetMinute() const
{ 
    return GetTm() ? GetTm()->tm_min : 0; 
}
int plUnifiedTime::GetSecond() const
{ 
    return GetTm() ? GetTm()->tm_sec : 0; 
}
int plUnifiedTime::GetDayOfWeek() const
{ 
    return GetTm() ? GetTm()->tm_wday : 0; 
}
int plUnifiedTime::GetMillis() const
{ 
    return fMicros/1000;
}

#pragma optimize( "g", off )    // disable global optimizations
double plUnifiedTime::GetSecsDouble() const
{
    hsDoublePrecBegin
    double ret = GetSecs() + GetMicros() / 1000000.0;
    hsDoublePrecEnd
    return ret;
}
#pragma optimize( "", on )  // restore optimizations to their defaults

UInt32 plUnifiedTime::AsMillis()
{
    return GetSecs()*1000;
}

void plUnifiedTime::Read(hsStream* s)
{
    s->LogSubStreamStart("UnifiedTime");
    s->LogReadSwap(&fSecs,"Seconds");
    s->LogReadSwap(&fMicros,"MicroSeconds");
    s->LogSubStreamEnd();
    // preserve fMode
}

void plUnifiedTime::Write(hsStream* s) const
{
    s->WriteSwap(fSecs);
    s->WriteSwap(fMicros);
    // preserve fMode
}

const plUnifiedTime & plUnifiedTime::operator-=(const plUnifiedTime & rhs)
{
    // carry if needed
    if ((*this).fMicros < rhs.fMicros)
    {
        (*this).fSecs--;
        (*this).fMicros += 1000000;
    }
    (*this).fMicros -= rhs.fMicros;
    (*this).fSecs -= rhs.fSecs;
    return *this;
}

const plUnifiedTime & plUnifiedTime::operator+=(const plUnifiedTime & rhs)
{
    (*this).fMicros += rhs.fMicros;
    // carry if needed
    if ((*this).fMicros >= 1000000)
    {
        (*this).fSecs++;
        (*this).fMicros -= 1000000;
    }
    (*this).fSecs += rhs.fSecs;
    return *this;
}

bool plUnifiedTime::operator==(const plUnifiedTime & rhs) const
{
    return ((fSecs == rhs.fSecs) && (fMicros == rhs.fMicros));
}
bool plUnifiedTime::operator!=(const plUnifiedTime & rhs) const
{
    return ((fSecs != rhs.fSecs) || (fMicros != rhs.fMicros));
}
bool plUnifiedTime::operator <(const plUnifiedTime & rhs) const
{
    return ((fSecs < rhs.fSecs) || ((fSecs == rhs.fSecs) && (fMicros < rhs.fMicros)));
}
bool plUnifiedTime::operator >(const plUnifiedTime & rhs) const
{
    return ((fSecs > rhs.fSecs) || ((fSecs == rhs.fSecs) && (fMicros > rhs.fMicros)));
}
bool plUnifiedTime::operator<=(const plUnifiedTime & rhs) const
{
    return (*this<rhs) || (*this==rhs);
}
bool plUnifiedTime::operator>=(const plUnifiedTime & rhs) const
{
    return (*this>rhs) || (*this==rhs);
}


plUnifiedTime::operator timeval() const
{
    struct timeval t = {fSecs, fMicros};
    return t;
}


plUnifiedTime::operator struct tm() const
{
    return *GetTm();
}


std::string plUnifiedTime::Format(const char * fmt) const
{
    char buf[128];
    struct tm * t = IGetTime((const time_t *)&fSecs);
    if (t == nil ||
        !strftime(buf, sizeof(buf), fmt, t))
        buf[0] = '\0';
    return std::string(buf);
}


plUnifiedTime operator -(const plUnifiedTime & left, const plUnifiedTime & right)
{
    plUnifiedTime ans = left;
    ans -= right;
    return ans;
}

plUnifiedTime operator +(const plUnifiedTime & left, const plUnifiedTime & right)
{
    plUnifiedTime ans = left;
    ans += right;
    return ans;
}

bool operator <(const plUnifiedTime & time, int secs)
{
    return (time.GetSecs()<secs);
}


////////////////////////////////////////////////////////////////////
// FromString

#if !defined(HS_BUILD_FOR_UNIX)

namespace pvt_strptime
{
    
    //
    // based on glibc's strptime
    //
    
#define __isleap(year)  \
    ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
    
#define match_char(ch1, ch2) if (ch1 != ch2) return NULL
#define match_string(cs1, s2) \
    (_strnicmp((cs1), (s2), strlen (cs1)) ? 0 : ((s2) += strlen (cs1), 1))
#define get_number(from, to, n) \
    do {                                          \
    int __n = n;                                  \
    val = 0;                                      \
    while (*rp == ' ')                                \
    ++rp;                                     \
    if (*rp < '0' || *rp > '9')                           \
    return NULL;                                  \
    do {                                      \
    val *= 10;                                \
    val += *rp++ - '0';                           \
    } while (--__n > 0 && val * 10 <= to && *rp >= '0' && *rp <= '9');        \
    if (val < from || val > to)                           \
    return NULL;                                  \
    } while (0)
#define recursive(new_fmt) \
    (*(new_fmt) != '\0'                               \
    && (rp = strptime_internal (rp, (new_fmt), tm, mode)) != NULL)
    
    static char const weekday_name[][10] =
    {
        "Sunday", "Monday", "Tuesday", "Wednesday",
            "Thursday", "Friday", "Saturday"
    };
    static char const ab_weekday_name[][4] =
    {
        "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
    };
    static char const month_name[][10] =
    {
        "January", "February", "March", "April", "May", "June",
            "July", "August", "September", "October", "November", "December"
    };
    static char const ab_month_name[][4] =
    {
        "Jan", "Feb", "Mar", "Apr", "May", "Jun",
            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
    };
#define HERE_D_T_FMT "%m/%d/%y %H:%M:%S"
#define HERE_D_FMT "%m/%d/%y"
#define HERE_AM_STR "AM"
#define HERE_PM_STR "PM"
#define HERE_T_FMT_AMPM "%I:%M:%S %p"
#define HERE_T_FMT "%H:%M:%S"
    
    const unsigned short int __mon_yday[2][13] =
    {
        /* Normal years.  */
        { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
            /* Leap years.  */
        { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
    };
    
    
    
    static struct tm *
        time_r(
        const time_t *t,
        struct tm *tp,
        int mode)
    {
        struct tm *l = 0;
        switch (mode)
        {
        case plUnifiedTime::kGmt:
            l = gmtime(t);
            break;
        default:
            l = localtime(t);
        }
        if (! l)
            return 0;
        *tp = *l;
        tp->tm_isdst = -1;
        return tp;
    }
    
    /* Compute the day of the week.  */
    static void
        day_of_the_week (struct tm *tm)
    {
    /* We know that January 1st 1970 was a Thursday (= 4).  Compute the
    the difference between this data in the one on TM and so determine
        the weekday.  */
        int corr_year = 1900 + tm->tm_year - (tm->tm_mon < 2);
        int wday = (-473
            + (365 * (tm->tm_year - 70))
            + (corr_year / 4)
            - ((corr_year / 4) / 25) + ((corr_year / 4) % 25 < 0)
            + (((corr_year / 4) / 25) / 4)
            + __mon_yday[0][tm->tm_mon]
            + tm->tm_mday - 1);
        tm->tm_wday = ((wday % 7) + 7) % 7;
    }
    
    /* Compute the day of the year.  */
    static void
        day_of_the_year (struct tm *tm)
    {
        tm->tm_yday = (__mon_yday[__isleap (1900 + tm->tm_year)][tm->tm_mon]
            + (tm->tm_mday - 1));
    }
    
    
    
    static char * strptime_internal(
        const char * rp,
        const char * fmt,
        struct tm * tm,
        int mode)
    {
        const char *rp_backup;
        int cnt;
        size_t val;
        int have_I, is_pm;
        int century, want_century;
        int have_wday, want_xday;
        int have_yday;
        int have_mon, have_mday;
        
        have_I = is_pm = 0;
        century = -1;
        want_century = 0;
        
        have_wday = want_xday = have_yday = have_mon = have_mday = 0;
        
        while (*fmt != '\0')
        {
        /* A white space in the format string matches 0 more or white
            space in the input string.  */
            if (isspace (*fmt))
            {
                while (isspace (*rp))
                    ++rp;
                ++fmt;
                continue;
            }
            
            /* Any character but `%' must be matched by the same character
            in the iput string.  */
            if (*fmt != '%')
            {
                match_char (*fmt++, *rp++);
                continue;
            }
            
            ++fmt;
            /* We need this for handling the `E' modifier.  */
start_over:
            
            /* Make back up of current processing pointer.  */
            rp_backup = rp;
            
            switch (*fmt++)
            {
            case '%':
                /* Match the `%' character itself.  */
                match_char ('%', *rp++);
                break;
            case 'a':
            case 'A':
                /* Match day of week.  */
                for (cnt = 0; cnt < 7; ++cnt)
                {
                    if (match_string (weekday_name[cnt], rp)
                        || match_string (ab_weekday_name[cnt], rp))
                    {
                        break;
                    }
                }
                if (cnt == 7)
                    /* Does not match a weekday name.  */
                    return NULL;
                tm->tm_wday = cnt;
                have_wday = 1;
                break;
            case 'b':
            case 'B':
            case 'h':
                /* Match month name.  */
                for (cnt = 0; cnt < 12; ++cnt)
                {
                    if (match_string (month_name[cnt], rp)
                        || match_string (ab_month_name[cnt], rp))
                    {
                        break;
                    }
                }
                if (cnt == 12)
                    /* Does not match a month name.  */
                    return NULL;
                tm->tm_mon = cnt;
                want_xday = 1;
                break;
            case 'c':
                /* Match locale's date and time format.  */
                if (!recursive (HERE_D_T_FMT))
                    return NULL;
                want_xday = 1;
                break;
            case 'C':
                /* Match century number.  */
                get_number (0, 99, 2);
                century = val;
                want_xday = 1;
                break;
            case 'd':
            case 'e':
                /* Match day of month.  */
                get_number (1, 31, 2);
                tm->tm_mday = val;
                have_mday = 1;
                want_xday = 1;
                break;
            case 'F':
                if (!recursive ("%Y-%m-%d"))
                    return NULL;
                want_xday = 1;
                break;
            case 'x':
                /* Fall through.  */
            case 'D':
                /* Match standard day format.  */
                if (!recursive (HERE_D_FMT))
                    return NULL;
                want_xday = 1;
                break;
            case 'k':
            case 'H':
                /* Match hour in 24-hour clock.  */
                get_number (0, 23, 2);
                tm->tm_hour = val;
                have_I = 0;
                break;
            case 'I':
                /* Match hour in 12-hour clock.  */
                get_number (1, 12, 2);
                tm->tm_hour = val % 12;
                have_I = 1;
                break;
            case 'j':
                /* Match day number of year.  */
                get_number (1, 366, 3);
                tm->tm_yday = val - 1;
                have_yday = 1;
                break;
            case 'm':
                /* Match number of month.  */
                get_number (1, 12, 2);
                tm->tm_mon = val - 1;
                have_mon = 1;
                want_xday = 1;
                break;
            case 'M':
                /* Match minute.  */
                get_number (0, 59, 2);
                tm->tm_min = val;
                break;
            case 'n':
            case 't':
                /* Match any white space.  */
                while (isspace (*rp))
                    ++rp;
                break;
            case 'p':
                /* Match locale's equivalent of AM/PM.  */
                if (!match_string (HERE_AM_STR, rp))
                    if (match_string (HERE_PM_STR, rp))
                        is_pm = 1;
                    else
                        return NULL;
                    break;
            case 'r':
                if (!recursive (HERE_T_FMT_AMPM))
                    return NULL;
                break;
            case 'R':
                if (!recursive ("%H:%M"))
                    return NULL;
                break;
            case 's':
                {
                /* The number of seconds may be very high so we cannot use
                the `get_number' macro.  Instead read the number
                character for character and construct the result while
                    doing this.  */
                    time_t secs = 0;
                    if (*rp < '0' || *rp > '9')
                        /* We need at least one digit.  */
                        return NULL;
                    
                    do
                    {
                        secs *= 10;
                        secs += *rp++ - '0';
                    }
                    while (*rp >= '0' && *rp <= '9');
                    
                    if (time_r (&secs, tm, mode) == NULL)
                        /* Error in function.  */
                        return NULL;
                }
                break;
            case 'S':
                get_number (0, 61, 2);
                tm->tm_sec = val;
                break;
            case 'X':
                /* Fall through.  */
            case 'T':
                if (!recursive (HERE_T_FMT))
                    return NULL;
                break;
            case 'u':
                get_number (1, 7, 1);
                tm->tm_wday = val % 7;
                have_wday = 1;
                break;
            case 'g':
                get_number (0, 99, 2);
                /* XXX This cannot determine any field in TM.  */
                break;
            case 'G':
                if (*rp < '0' || *rp > '9')
                    return NULL;
                    /* XXX Ignore the number since we would need some more
                information to compute a real date.  */
                do
                ++rp;
                while (*rp >= '0' && *rp <= '9');
                break;
            case 'U':
            case 'V':
            case 'W':
                get_number (0, 53, 2);
                /* XXX This cannot determine any field in TM without some
                information.  */
                break;
            case 'w':
                /* Match number of weekday.  */
                get_number (0, 6, 1);
                tm->tm_wday = val;
                have_wday = 1;
                break;
            case 'y':
                /* Match year within century.  */
                get_number (0, 99, 2);
                /* The "Year 2000: The Millennium Rollover" paper suggests that
                values in the range 69-99 refer to the twentieth century.  */
                tm->tm_year = val >= 69 ? val : val + 100;
                /* Indicate that we want to use the century, if specified.  */
                want_century = 1;
                want_xday = 1;
                break;
            case 'Y':
                /* Match year including century number.  */
                get_number (0, 9999, 4);
                tm->tm_year = val - 1900;
                want_century = 0;
                want_xday = 1;
                break;
                
                goto start_over;
                
            case 'O':
                switch (*fmt++)
                {
                case 'd':
                case 'e':
                    /* Match day of month using alternate numeric symbols.  */
                    get_number (1, 31, 2);
                    tm->tm_mday = val;
                    have_mday = 1;
                    want_xday = 1;
                    break;
                case 'H':
                /* Match hour in 24-hour clock using alternate numeric
                    symbols.  */
                    get_number (0, 23, 2);
                    tm->tm_hour = val;
                    have_I = 0;
                    break;
                case 'I':
                /* Match hour in 12-hour clock using alternate numeric
                    symbols.  */
                    get_number (1, 12, 2);
                    tm->tm_hour = val - 1;
                    have_I = 1;
                    break;
                case 'm':
                    /* Match month using alternate numeric symbols.  */
                    get_number (1, 12, 2);
                    tm->tm_mon = val - 1;
                    have_mon = 1;
                    want_xday = 1;
                    break;
                case 'M':
                    /* Match minutes using alternate numeric symbols.  */
                    get_number (0, 59, 2);
                    tm->tm_min = val;
                    break;
                case 'S':
                    /* Match seconds using alternate numeric symbols.  */
                    get_number (0, 61, 2);
                    tm->tm_sec = val;
                    break;
                case 'U':
                case 'V':
                case 'W':
                    get_number (0, 53, 2);
                    /* XXX This cannot determine any field in TM without
                    further information.  */
                    break;
                case 'w':
                    /* Match number of weekday using alternate numeric symbols.  */
                    get_number (0, 6, 1);
                    tm->tm_wday = val;
                    have_wday = 1;
                    break;
                case 'y':
                    /* Match year within century using alternate numeric symbols.  */
                    get_number (0, 99, 2);
                    tm->tm_year = val >= 69 ? val : val + 100;
                    want_xday = 1;
                    break;
                default:
                    return NULL;
                }
                break;
                default:
                    return NULL;
    }
    }
    
    if (have_I && is_pm)
        tm->tm_hour += 12;
    
    if (century != -1)
    {
        if (want_century)
            tm->tm_year = tm->tm_year % 100 + (century - 19) * 100;
        else
            /* Only the century, but not the year.  Strange, but so be it.  */
            tm->tm_year = (century - 19) * 100;
    }
    
    if (want_xday && !have_wday)
    {
        if ( !(have_mon && have_mday) && have_yday)
        {
            /* We don't have tm_mon and/or tm_mday, compute them.  */
            int t_mon = 0;
            while (__mon_yday[__isleap(1900 + tm->tm_year)][t_mon] <= tm->tm_yday)
                t_mon++;
            if (!have_mon)
                tm->tm_mon = t_mon - 1;
            if (!have_mday)
                tm->tm_mday =
                (tm->tm_yday
                - __mon_yday[__isleap(1900 + tm->tm_year)][t_mon - 1] + 1);
        }
        day_of_the_week (tm);
    }
    if (want_xday && !have_yday)
        day_of_the_year (tm);
    
    return (char *) rp;
}


}   // namespace pvt_strptime

#endif

bool plUnifiedTime::FromString(const char * buf, const char * fmt)
{
    struct tm tm;
    tm.tm_isdst = -1;
#if !defined(HS_BUILD_FOR_UNIX)
    bool result = (pvt_strptime::strptime_internal(buf, fmt, &tm, fMode)!=nil);
#else
    bool result = (strptime(buf, fmt, &tm)!=nil);
#endif
    if (result)
        *this = tm;
    return result;
}

/// Local time zone offset stuff

Int32   plUnifiedTime::fLocalTimeZoneOffset = -1;

Int32   plUnifiedTime::IGetLocalTimeZoneOffset( void )
{
    static bool     inited = false;

    if( !inited )
    {
        inited = true;

        // Calculate the difference between local time and GMT for this system currently
        // Taken from devx.com from an article written by Danny Kalev
        // http://gethelp.devx.com/techtips/cpp_pro/10min/2001/10min1200-3.asp

        time_t  currLocalTime = time( 0 );      // current local time

        struct tm   local = *gmtime( &currLocalTime );  // convert curr to GMT, store as tm
        
        time_t      utc = mktime( &local ); // convert GMT tm to GMT time_t

        double diffInSecs = difftime( utc, currLocalTime );

        fLocalTimeZoneOffset = (Int32)diffInSecs;
    }

    return fLocalTimeZoneOffset;
}

//
// static helper, return difference timeA-timeB, may be negative
//
double plUnifiedTime::GetTimeDifference(const plUnifiedTime& timeA, const plUnifiedTime& timeB)
{
    bool neg = (timeB > timeA);
    plUnifiedTime timeDiff = neg ? (timeB - timeA) : (timeA - timeB);   // always positive
    double t = (float)(neg ? timeDiff.GetSecsDouble() * -1. : timeDiff.GetSecsDouble());
    return t;
}