prtime.c

Netscape NSPR库源码

             * assuming the time zone has not changed since then.
             */
            retVal.tp_gmt_offset = offset2Jan1970;
            retVal.tp_dst_offset = offsetNew - offset2Jan1970;
        } else {
            /*
             * DST was also in effect back in 2 Jan. 1970.
             * Then our clever trick (or rather, ugly hack) fails.
             * We will just assume DST offset is an hour.
             */
            retVal.tp_gmt_offset = offsetNew - 3600;
            retVal.tp_dst_offset = 3600;
        }
    }
    
    return retVal;
}

#endif    /* defined(XP_UNIX) !! defined(XP_PC) */

/*
 *------------------------------------------------------------------------
 *
 * PR_USPacificTimeParameters --
 *
 *     The time parameters function for the US Pacific Time Zone.
 *
 *------------------------------------------------------------------------
 */

PR_IMPLEMENT(PRTimeParameters)
PR_USPacificTimeParameters(const PRExplodedTime *gmt)
{
    PRTimeParameters retVal;
    PRExplodedTime st;

    /*
     * Based on geographic location and GMT, figure out offset of
     * standard time from GMT.  In this example implementation, we
     * assume the local time zone is US Pacific Time.
     */

    retVal.tp_gmt_offset = -8L * 3600L;

    /*
     * Make a copy of GMT.  Note that the tm_params field of this copy
     * is ignored.
     */

    st.tm_usec = gmt->tm_usec;
    st.tm_sec = gmt->tm_sec;
    st.tm_min = gmt->tm_min;
    st.tm_hour = gmt->tm_hour;
    st.tm_mday = gmt->tm_mday;
    st.tm_month = gmt->tm_month;
    st.tm_year = gmt->tm_year;
    st.tm_wday = gmt->tm_wday;
    st.tm_yday = gmt->tm_yday;

    /* Apply the offset to GMT to obtain the local standard time */
    ApplySecOffset(&st, retVal.tp_gmt_offset);

    /*
     * Apply the rules on standard time or GMT to obtain daylight saving
     * time offset.  In this implementation, we use the US DST rule.
     */
    if (st.tm_month < 3) {
        retVal.tp_dst_offset = 0L;
    } else if (st.tm_month == 3) {
        if (st.tm_wday == 0) {
            /* A Sunday */
            if (st.tm_mday <= 7) {
                /* First Sunday */
                /* 01:59:59 PST -> 03:00:00 PDT */
                if (st.tm_hour < 2) {
                    retVal.tp_dst_offset = 0L;
                } else {
                    retVal.tp_dst_offset = 3600L;
                }
            } else {
                /* Not first Sunday */
                retVal.tp_dst_offset = 3600L;
            }
        } else {
            /* Not a Sunday.  See if before first Sunday or after */
            if (st.tm_wday + 1 <= st.tm_mday) {
                /* After first Sunday */
                retVal.tp_dst_offset = 3600L;
            } else {
                /* Before first Sunday */
                retVal.tp_dst_offset = 0L;
            } 
        }
    } else if (st.tm_month < 9) {
        retVal.tp_dst_offset = 3600L;
    } else if (st.tm_month == 9) {
        if (st.tm_wday == 0) {
            if (31 - st.tm_mday < 7) {
                /* Last Sunday */
                /* 01:59:59 PDT -> 01:00:00 PST */
                if (st.tm_hour < 1) {
                    retVal.tp_dst_offset = 3600L;
                } else {
                    retVal.tp_dst_offset = 0L;
                }
            } else {
                /* Not last Sunday */
                retVal.tp_dst_offset = 3600L;
            }
        } else {
            /* See if before or after last Sunday */
            if (7 - st.tm_wday <= 31 - st.tm_mday) {
                /* before last Sunday */
                retVal.tp_dst_offset = 3600L;
            } else {
                retVal.tp_dst_offset = 0L;
            }
        }
    } else {
        retVal.tp_dst_offset = 0L;
    }
    return retVal;
}

/*
 *------------------------------------------------------------------------
 *
 * PR_GMTParameters --
 *
 *     Returns the PRTimeParameters for Greenwich Mean Time.
 *     Trivially, both the tp_gmt_offset and tp_dst_offset fields are 0.
 *
 *------------------------------------------------------------------------
 */

PR_IMPLEMENT(PRTimeParameters)
PR_GMTParameters(const PRExplodedTime *gmt)
{
#if defined(XP_MAC)
#pragma unused (gmt)
#endif

    PRTimeParameters retVal = { 0, 0 };
    return retVal;
}

/*
 * The following code implements PR_ParseTimeString().  It is based on
 * ns/lib/xp/xp_time.c, revision 1.25, by Jamie Zawinski <[e-mail]>.
 */

/*
 * We only recognize the abbreviations of a small subset of time zones
 * in North America, Europe, and Japan.
 *
 * PST/PDT: Pacific Standard/Daylight Time
 * MST/MDT: Mountain Standard/Daylight Time
 * CST/CDT: Central Standard/Daylight Time
 * EST/EDT: Eastern Standard/Daylight Time
 * AST: Atlantic Standard Time
 * NST: Newfoundland Standard Time
 * GMT: Greenwich Mean Time
 * BST: British Summer Time
 * MET: Middle Europe Time
 * EET: Eastern Europe Time
 * JST: Japan Standard Time
 */

typedef enum
{
  TT_UNKNOWN,

  TT_SUN, TT_MON, TT_TUE, TT_WED, TT_THU, TT_FRI, TT_SAT,

  TT_JAN, TT_FEB, TT_MAR, TT_APR, TT_MAY, TT_JUN,
  TT_JUL, TT_AUG, TT_SEP, TT_OCT, TT_NOV, TT_DEC,

  TT_PST, TT_PDT, TT_MST, TT_MDT, TT_CST, TT_CDT, TT_EST, TT_EDT,
  TT_AST, TT_NST, TT_GMT, TT_BST, TT_MET, TT_EET, TT_JST
} TIME_TOKEN;

/*
 * This parses a time/date string into a PRTime
 * (microseconds after "1-Jan-1970 00:00:00 GMT").
 * It returns PR_SUCCESS on success, and PR_FAILURE
 * if the time/date string can't be parsed.
 *
 * Many formats are handled, including:
 *
 *   14 Apr 89 03:20:12
 *   14 Apr 89 03:20 GMT
 *   Fri, 17 Mar 89 4:01:33
 *   Fri, 17 Mar 89 4:01 GMT
 *   Mon Jan 16 16:12 PDT 1989
 *   Mon Jan 16 16:12 +0130 1989
 *   6 May 1992 16:41-JST (Wednesday)
 *   22-AUG-1993 10:59:12.82
 *   22-AUG-1993 10:59pm
 *   22-AUG-1993 12:59am
 *   22-AUG-1993 12:59 PM
 *   Friday, August 04, 1995 3:54 PM
 *   06/21/95 04:24:34 PM
 *   20/06/95 21:07
 *   95-06-08 19:32:48 EDT
 *
 * If the input string doesn't contain a description of the timezone,
 * we consult the `default_to_gmt' to decide whether the string should
 * be interpreted relative to the local time zone (PR_FALSE) or GMT (PR_TRUE).
 * The correct value for this argument depends on what standard specified
 * the time string which you are parsing.
 */

PR_IMPLEMENT(PRStatus)
PR_ParseTimeString(
        const char *string,
        PRBool default_to_gmt,
        PRTime *result)
{
  PRExplodedTime tm;
  TIME_TOKEN dotw = TT_UNKNOWN;
  TIME_TOKEN month = TT_UNKNOWN;
  TIME_TOKEN zone = TT_UNKNOWN;
  int zone_offset = -1;
  int date = -1;
  PRInt32 year = -1;
  int hour = -1;
  int min = -1;
  int sec = -1;

  const char *rest = string;

#ifdef DEBUG
  int iterations = 0;
#endif

  PR_ASSERT(string && result);
  if (!string || !result) return PR_FAILURE;

  while (*rest)
        {

#ifdef DEBUG
          if (iterations++ > 1000)
                {
                  PR_ASSERT(0);
                  return PR_FAILURE;
                }
#endif

          switch (*rest)
                {
                case 'a': case 'A':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'p' || rest[1] == 'P') &&
                          (rest[2] == 'r' || rest[2] == 'R'))
                        month = TT_APR;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 's') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_AST;
                  else if (month == TT_UNKNOWN &&
                                   (rest[1] == 'u' || rest[1] == 'U') &&
                                   (rest[2] == 'g' || rest[2] == 'G'))
                        month = TT_AUG;
                  break;
                case 'b': case 'B':
                  if (zone == TT_UNKNOWN &&
                          (rest[1] == 's' || rest[1] == 'S') &&
                          (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_BST;
                  break;
                case 'c': case 'C':
                  if (zone == TT_UNKNOWN &&
                          (rest[1] == 'd' || rest[1] == 'D') &&
                          (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_CDT;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 'S') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_CST;
                  break;
                case 'd': case 'D':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'e' || rest[1] == 'E') &&
                          (rest[2] == 'c' || rest[2] == 'C'))
                        month = TT_DEC;
                  break;
                case 'e': case 'E':
                  if (zone == TT_UNKNOWN &&
                          (rest[1] == 'd' || rest[1] == 'D') &&
                          (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_EDT;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 'e' || rest[1] == 'E') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_EET;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 'S') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_EST;
                  break;
                case 'f': case 'F':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'e' || rest[1] == 'E') &&
                          (rest[2] == 'b' || rest[2] == 'B'))
                        month = TT_FEB;
                  else if (dotw == TT_UNKNOWN &&
                                   (rest[1] == 'r' || rest[1] == 'R') &&
                                   (rest[2] == 'i' || rest[2] == 'I'))
                        dotw = TT_FRI;
                  break;
                case 'g': case 'G':
                  if (zone == TT_UNKNOWN &&
                          (rest[1] == 'm' || rest[1] == 'M') &&
                          (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_GMT;
                  break;
                case 'j': case 'J':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'a' || rest[1] == 'A') &&
                          (rest[2] == 'n' || rest[2] == 'N'))
                        month = TT_JAN;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 'S') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_JST;
                  else if (month == TT_UNKNOWN &&
                                   (rest[1] == 'u' || rest[1] == 'U') &&
                                   (rest[2] == 'l' || rest[2] == 'L'))
                        month = TT_JUL;
                  else if (month == TT_UNKNOWN &&
                                   (rest[1] == 'u' || rest[1] == 'U') &&
                                   (rest[2] == 'n' || rest[2] == 'N'))
                        month = TT_JUN;
                  break;
                case 'm': case 'M':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'a' || rest[1] == 'A') &&
                          (rest[2] == 'r' || rest[2] == 'R'))
                        month = TT_MAR;
                  else if (month == TT_UNKNOWN &&
                                   (rest[1] == 'a' || rest[1] == 'A') &&
                                   (rest[2] == 'y' || rest[2] == 'Y'))
                        month = TT_MAY;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 'd' || rest[1] == 'D') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_MDT;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 'e' || rest[1] == 'E') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_MET;
                  else if (dotw == TT_UNKNOWN &&
                                   (rest[1] == 'o' || rest[1] == 'O') &&
                                   (rest[2] == 'n' || rest[2] == 'N'))
                        dotw = TT_MON;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 'S') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_MST;
                  break;
                case 'n': case 'N':
                  if (month == TT_UNKNOWN &&
                          (rest[1] == 'o' || rest[1] == 'O') &&
                          (rest[2] == 'v' || rest[2] == 'V'))
                        month = TT_NOV;
                  else if (zone == TT_UNKNOWN &&
                                   (rest[1] == 's' || rest[1] == 'S') &&
                                   (rest[2] == 't' || rest[2] == 'T'))
                        zone = TT_NST;
                  break;