prtime.c

Netscape NSPR库源码

        }

  if (zone != TT_UNKNOWN && zone_offset == -1)
        {
          switch (zone)
                {
                case TT_PST: zone_offset = -8 * 60; break;
                case TT_PDT: zone_offset = -7 * 60; break;
                case TT_MST: zone_offset = -7 * 60; break;
                case TT_MDT: zone_offset = -6 * 60; break;
                case TT_CST: zone_offset = -6 * 60; break;
                case TT_CDT: zone_offset = -5 * 60; break;
                case TT_EST: zone_offset = -5 * 60; break;
                case TT_EDT: zone_offset = -4 * 60; break;
                case TT_AST: zone_offset = -4 * 60; break;
                case TT_NST: zone_offset = -3 * 60 - 30; break;
                case TT_GMT: zone_offset =  0 * 60; break;
                case TT_BST: zone_offset =  1 * 60; break;
                case TT_MET: zone_offset =  1 * 60; break;
                case TT_EET: zone_offset =  2 * 60; break;
                case TT_JST: zone_offset =  9 * 60; break;
                default:
                  PR_ASSERT (0);
                  break;
                }
        }

  /* If we didn't find a year, month, or day-of-the-month, we can't
         possibly parse this, and in fact, mktime() will do something random
         (I'm seeing it return "Tue Feb  5 06:28:16 2036", which is no doubt
         a numerologically significant date... */
  if (month == TT_UNKNOWN || date == -1 || year == -1)
      return PR_FAILURE;

  memset(&tm, 0, sizeof(tm));
  if (sec != -1)
        tm.tm_sec = sec;
  if (min != -1)
  tm.tm_min = min;
  if (hour != -1)
        tm.tm_hour = hour;
  if (date != -1)
        tm.tm_mday = date;
  if (month != TT_UNKNOWN)
        tm.tm_month = (((int)month) - ((int)TT_JAN));
  if (year != -1)
        tm.tm_year = year;
  if (dotw != TT_UNKNOWN)
        tm.tm_wday = (((int)dotw) - ((int)TT_SUN));

  if (zone == TT_UNKNOWN && default_to_gmt)
        {
          /* No zone was specified, so pretend the zone was GMT. */
          zone = TT_GMT;
          zone_offset = 0;
        }

  if (zone_offset == -1)
         {
           /* no zone was specified, and we're to assume that everything
             is local. */
          struct tm localTime;
          time_t secs;

          PR_ASSERT(tm.tm_month > -1 
                                   && tm.tm_mday > 0 
                                   && tm.tm_hour > -1
                                   && tm.tm_min > -1
                                   && tm.tm_sec > -1);

            /*
             * To obtain time_t from a tm structure representing the local
             * time, we call mktime().  However, we need to see if we are
             * on 1-Jan-1970 or before.  If we are, we can't call mktime()
             * because mktime() will crash on win16. In that case, we
             * calculate zone_offset based on the zone offset at 
             * 00:00:00, 2 Jan 1970 GMT, and subtract zone_offset from the
             * date we are parsing to transform the date to GMT.  We also
             * do so if mktime() returns (time_t) -1 (time out of range).
           */

          /* month, day, hours, mins and secs are always non-negative
             so we dont need to worry about them. */  
            if(tm.tm_year >= 1970)
                {
                  PRInt64 usec_per_sec;

                  localTime.tm_sec = tm.tm_sec;
                  localTime.tm_min = tm.tm_min;
                  localTime.tm_hour = tm.tm_hour;
                  localTime.tm_mday = tm.tm_mday;
                  localTime.tm_mon = tm.tm_month;
                  localTime.tm_year = tm.tm_year - 1900;
                  /* Set this to -1 to tell mktime "I don't care".  If you set
                     it to 0 or 1, you are making assertions about whether the
                     date you are handing it is in daylight savings mode or not;
                     and if you're wrong, it will "fix" it for you. */
                  localTime.tm_isdst = -1;
                  secs = mktime(&localTime);
                  if (secs != (time_t) -1)
                    {
#if defined(XP_MAC) && (__MSL__ < 0x6000)
                      /*
                       * The mktime() routine in MetroWerks MSL C
                       * Runtime library returns seconds since midnight,
                       * 1 Jan. 1900, not 1970 - in versions of MSL (Metrowerks Standard
                       * Library) prior to version 6.  Only for older versions of
                       * MSL do we adjust the value of secs to the NSPR epoch
                       */
                      secs -= ((365 * 70UL) + 17) * 24 * 60 * 60;
#endif
                      LL_I2L(*result, secs);
                      LL_I2L(usec_per_sec, PR_USEC_PER_SEC);
                      LL_MUL(*result, *result, usec_per_sec);
                      return PR_SUCCESS;
                    }
                }
                
                /* So mktime() can't handle this case.  We assume the
                   zone_offset for the date we are parsing is the same as
                   the zone offset on 00:00:00 2 Jan 1970 GMT. */
                secs = 86400;
                (void) MT_safe_localtime(&secs, &localTime);
                zone_offset = localTime.tm_min
                              + 60 * localTime.tm_hour
                              + 1440 * (localTime.tm_mday - 2);
        }

        /* Adjust the hours and minutes before handing them to
           PR_ImplodeTime(). Note that it's ok for them to be <0 or >24/60 

           We adjust the time to GMT before going into PR_ImplodeTime().
           The zone_offset represents the difference between the time
           zone parsed and GMT
         */
        tm.tm_hour -= (zone_offset / 60);
        tm.tm_min  -= (zone_offset % 60);

  *result = PR_ImplodeTime(&tm);

  return PR_SUCCESS;
}

/*
 *******************************************************************
 *******************************************************************
 **
 **    OLD COMPATIBILITY FUNCTIONS
 **
 *******************************************************************
 *******************************************************************
 */


/*
 *-----------------------------------------------------------------------
 *
 * PR_FormatTime --
 *
 *     Format a time value into a buffer. Same semantics as strftime().
 *
 *-----------------------------------------------------------------------
 */

PR_IMPLEMENT(PRUint32)
PR_FormatTime(char *buf, int buflen, const char *fmt, const PRExplodedTime *tm)
{
    struct tm a;
    a.tm_sec = tm->tm_sec;
    a.tm_min = tm->tm_min;
    a.tm_hour = tm->tm_hour;
    a.tm_mday = tm->tm_mday;
    a.tm_mon = tm->tm_month;
    a.tm_wday = tm->tm_wday;
    a.tm_year = tm->tm_year - 1900;
    a.tm_yday = tm->tm_yday;
    a.tm_isdst = tm->tm_params.tp_dst_offset ? 1 : 0;

/*
 * On some platforms, for example SunOS 4, struct tm has two additional
 * fields: tm_zone and tm_gmtoff.  The following code attempts to obtain
 * values for these two fields.
 */

#if defined(SUNOS4) || (__GLIBC__ >= 2) || defined(XP_BEOS)
    if (mktime(&a) == -1) {
        PR_snprintf(buf, buflen, "can't get timezone");
        return 0;
    }
#endif

    return strftime(buf, buflen, fmt, &a);
}


/*
 * The following string arrays and macros are used by PR_FormatTimeUSEnglish().
 */

static const char* abbrevDays[] =
{
   "Sun","Mon","Tue","Wed","Thu","Fri","Sat"
};

static const char* days[] =
{
   "Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"
};

static const char* abbrevMonths[] =
{
   "Jan", "Feb", "Mar", "Apr", "May", "Jun",
   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};

static const char* months[] =
{ 
    "January", "February", "March", "April", "May", "June",
    "July", "August", "September", "October", "November", "December"
};


/*
 * Add a single character to the given buffer, incrementing the buffer pointer
 * and decrementing the buffer size. Return 0 on error.
 */
#define ADDCHAR( buf, bufSize, ch )             \
do                                              \
{                                               \
   if( bufSize < 1 )                            \
   {                                            \
      *(--buf) = '\0';                          \
      return 0;                                 \
   }                                            \
   *buf++ = ch;                                 \
   bufSize--;                                   \
}                                               \
while(0)


/*
 * Add a string to the given buffer, incrementing the buffer pointer
 * and decrementing the buffer size appropriately.  Return 0 on error.
 */
#define ADDSTR( buf, bufSize, str )             \
do                                              \
{                                               \
   PRUint32 strSize = strlen( str );              \
   if( strSize > bufSize )                      \
   {                                            \
      if( bufSize==0 )                          \
         *(--buf) = '\0';                       \
      else                                      \
         *buf = '\0';                           \
      return 0;                                 \
   }                                            \
   memcpy(buf, str, strSize);                   \
   buf += strSize;                              \
   bufSize -= strSize;                          \
}                                               \
while(0)

/* Needed by PR_FormatTimeUSEnglish() */
static unsigned int  pr_WeekOfYear(const PRExplodedTime* time,
        unsigned int firstDayOfWeek);


/***********************************************************************************
 *
 * Description:
 *  This is a dumbed down version of strftime that will format the date in US
 *  English regardless of the setting of the global locale.  This functionality is
 *  needed to write things like MIME headers which must always be in US English.
 *
 **********************************************************************************/
             
PR_IMPLEMENT(PRUint32)
PR_FormatTimeUSEnglish( char* buf, PRUint32 bufSize,
                        const char* format, const PRExplodedTime* time )
{
   char*         bufPtr = buf;
   const char*   fmtPtr;
   char          tmpBuf[ 40 ];        
   const int     tmpBufSize = sizeof( tmpBuf );

   
   for( fmtPtr=format; *fmtPtr != '\0'; fmtPtr++ )
   {
      if( *fmtPtr != '%' )
      {
         ADDCHAR( bufPtr, bufSize, *fmtPtr );
      }
      else
      {
         switch( *(++fmtPtr) )
         {
         case '%':
            /* escaped '%' character */
            ADDCHAR( bufPtr, bufSize, '%' );
            break;
            
         case 'a':
            /* abbreviated weekday name */
            ADDSTR( bufPtr, bufSize, abbrevDays[ time->tm_wday ] );
            break;
               
         case 'A':
            /* full weekday name */
            ADDSTR( bufPtr, bufSize, days[ time->tm_wday ] );
            break;
        
         case 'b':
            /* abbreviated month name */
            ADDSTR( bufPtr, bufSize, abbrevMonths[ time->tm_month ] );
            break;
        
         case 'B':
            /* full month name */
            ADDSTR(bufPtr, bufSize,  months[ time->tm_month ] );
            break;
        
         case 'c':
            /* Date and time. */
            PR_FormatTimeUSEnglish( tmpBuf, tmpBufSize, "%a %b %d %H:%M:%S %Y", time );
            ADDSTR( bufPtr, bufSize, tmpBuf );
            break;
        
         case 'd':
            /* day of month ( 01 - 31 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.2ld",time->tm_mday );
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;

         case 'H':
            /* hour ( 00 - 23 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.2ld",time->tm_hour );
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;
        
         case 'I':
            /* hour ( 01 - 12 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.2ld",
                        (time->tm_hour%12) ? time->tm_hour%12 : (PRInt32) 12 );
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;
        
         case 'j':
            /* day number of year ( 001 - 366 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.3d",time->tm_yday + 1);
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;
        
         case 'm':
            /* month number ( 01 - 12 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.2ld",time->tm_month+1);
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;
        
         case 'M':
            /* minute ( 00 - 59 ) */
            PR_snprintf(tmpBuf,tmpBufSize,"%.2ld",time->tm_min );
            ADDSTR( bufPtr, bufSize, tmpBuf ); 
            break;
       
         case 'p':
            /* locale's equivalent of either AM or PM */
            ADDSTR( bufPtr, bufSize, (time->tm_hour<12)?"AM":"PM" ); 
            break;