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Diffstat (limited to 'win/tclWinTime.c')
| -rw-r--r-- | win/tclWinTime.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/win/tclWinTime.c b/win/tclWinTime.c new file mode 100644 index 0000000..b59f68d --- /dev/null +++ b/win/tclWinTime.c @@ -0,0 +1,373 @@ +/* + * tclWinTime.c -- + * + * Contains Windows specific versions of Tcl functions that + * obtain time values from the operating system. + * + * Copyright 1995 by Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * SCCS: @(#) tclWinTime.c 1.6 97/04/14 17:25:56 + */ + +#include "tclInt.h" +#include "tclPort.h" + +#define SECSPERDAY (60L * 60L * 24L) +#define SECSPERYEAR (SECSPERDAY * 365L) +#define SECSPER4YEAR (SECSPERYEAR * 4L + SECSPERDAY) + +/* + * The following arrays contain the day of year for the last day of + * each month, where index 1 is January. + */ + +static int normalDays[] = { + -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 +}; + +static int leapDays[] = { + -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 +}; + +/* + * Declarations for functions defined later in this file. + */ + +static struct tm * ComputeGMT _ANSI_ARGS_((const time_t *tp)); + +/* + *---------------------------------------------------------------------- + * + * TclpGetSeconds -- + * + * This procedure returns the number of seconds from the epoch. + * On most Unix systems the epoch is Midnight Jan 1, 1970 GMT. + * + * Results: + * Number of seconds from the epoch. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +unsigned long +TclpGetSeconds() +{ + return (unsigned long) time((time_t *) NULL); +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetClicks -- + * + * This procedure returns a value that represents the highest + * resolution clock available on the system. There are no + * guarantees on what the resolution will be. In Tcl we will + * call this value a "click". The start time is also system + * dependant. + * + * Results: + * Number of clicks from some start time. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +unsigned long +TclpGetClicks() +{ + return GetTickCount(); +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetTimeZone -- + * + * Determines the current timezone. The method varies wildly + * between different Platform implementations, so its hidden in + * this function. + * + * Results: + * Minutes west of GMT. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TclpGetTimeZone (currentTime) + unsigned long currentTime; +{ + int timeZone; + + tzset(); + timeZone = _timezone / 60; + + return timeZone; +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetTime -- + * + * Gets the current system time in seconds and microseconds + * since the beginning of the epoch: 00:00 UCT, January 1, 1970. + * + * Results: + * Returns the current time in timePtr. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +void +TclpGetTime(timePtr) + Tcl_Time *timePtr; /* Location to store time information. */ +{ + struct timeb t; + + ftime(&t); + timePtr->sec = t.time; + timePtr->usec = t.millitm * 1000; +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetTZName -- + * + * Gets the current timezone string. + * + * Results: + * Returns a pointer to a static string, or NULL on failure. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +char * +TclpGetTZName() +{ + tzset(); + if (_daylight && _tzname[1] != NULL) { + return _tzname[1]; + } else { + return _tzname[0]; + } +} + +/* + *---------------------------------------------------------------------- + * + * TclpGetDate -- + * + * This function converts between seconds and struct tm. If + * useGMT is true, then the returned date will be in Greenwich + * Mean Time (GMT). Otherwise, it will be in the local time zone. + * + * Results: + * Returns a static tm structure. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +struct tm * +TclpGetDate(tp, useGMT) + const time_t *tp; + int useGMT; +{ + struct tm *tmPtr; + long time; + + if (!useGMT) { + tzset(); + + /* + * If we are in the valid range, let the C run-time library + * handle it. Otherwise we need to fake it. Note that this + * algorithm ignores daylight savings time before the epoch. + */ + + time = *tp - _timezone; + if (time >= 0) { + return localtime(tp); + } + + /* + * If we aren't near to overflowing the long, just add the bias and + * use the normal calculation. Otherwise we will need to adjust + * the result at the end. + */ + + if (*tp < (LONG_MAX - 2 * SECSPERDAY) + && *tp > (LONG_MIN + 2 * SECSPERDAY)) { + tmPtr = ComputeGMT(&time); + } else { + tmPtr = ComputeGMT(tp); + + tzset(); + + /* + * Add the bias directly to the tm structure to avoid overflow. + * Propagate seconds overflow into minutes, hours and days. + */ + + time = tmPtr->tm_sec - _timezone; + tmPtr->tm_sec = (int)(time % 60); + if (tmPtr->tm_sec < 0) { + tmPtr->tm_sec += 60; + time -= 60; + } + + time = tmPtr->tm_min + time/60; + tmPtr->tm_min = (int)(time % 60); + if (tmPtr->tm_min < 0) { + tmPtr->tm_min += 60; + time -= 60; + } + + time = tmPtr->tm_hour + time/60; + tmPtr->tm_hour = (int)(time % 24); + if (tmPtr->tm_hour < 0) { + tmPtr->tm_hour += 24; + time -= 24; + } + + time /= 24; + tmPtr->tm_mday += time; + tmPtr->tm_yday += time; + tmPtr->tm_wday = (tmPtr->tm_wday + time) % 7; + } + } else { + tmPtr = ComputeGMT(tp); + } + return tmPtr; +} + +/* + *---------------------------------------------------------------------- + * + * ComputeGMT -- + * + * This function computes GMT given the number of seconds since + * the epoch (midnight Jan 1 1970). + * + * Results: + * Returns a statically allocated struct tm. + * + * Side effects: + * Updates the values of the static struct tm. + * + *---------------------------------------------------------------------- + */ + +static struct tm * +ComputeGMT(tp) + const time_t *tp; +{ + static struct tm tm; /* This should be allocated per thread.*/ + long tmp, rem; + int isLeap; + int *days; + + /* + * Compute the 4 year span containing the specified time. + */ + + tmp = *tp / SECSPER4YEAR; + rem = *tp % SECSPER4YEAR; + + /* + * Correct for weird mod semantics so the remainder is always positive. + */ + + if (rem < 0) { + tmp--; + rem += SECSPER4YEAR; + } + + /* + * Compute the year after 1900 by taking the 4 year span and adjusting + * for the remainder. This works because 2000 is a leap year, and + * 1900/2100 are out of the range. + */ + + tmp = (tmp * 4) + 70; + isLeap = 0; + if (rem >= SECSPERYEAR) { /* 1971, etc. */ + tmp++; + rem -= SECSPERYEAR; + if (rem >= SECSPERYEAR) { /* 1972, etc. */ + tmp++; + rem -= SECSPERYEAR; + if (rem >= SECSPERYEAR + SECSPERDAY) { /* 1973, etc. */ + tmp++; + rem -= SECSPERYEAR + SECSPERDAY; + } else { + isLeap = 1; + } + } + } + tm.tm_year = tmp; + + /* + * Compute the day of year and leave the seconds in the current day in + * the remainder. + */ + + tm.tm_yday = rem / SECSPERDAY; + rem %= SECSPERDAY; + + /* + * Compute the time of day. + */ + + tm.tm_hour = rem / 3600; + rem %= 3600; + tm.tm_min = rem / 60; + tm.tm_sec = rem % 60; + + /* + * Compute the month and day of month. + */ + + days = (isLeap) ? leapDays : normalDays; + for (tmp = 1; days[tmp] < tm.tm_yday; tmp++) { + } + tm.tm_mon = --tmp; + tm.tm_mday = tm.tm_yday - days[tmp]; + + /* + * Compute day of week. Epoch started on a Thursday. + */ + + tm.tm_wday = (*tp / SECSPERDAY) + 4; + if ((*tp % SECSPERDAY) < 0) { + tm.tm_wday--; + } + tm.tm_wday %= 7; + if (tm.tm_wday < 0) { + tm.tm_wday += 7; + } + + return &tm; +} |