1 {-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
2 -- JRS 010117: we had to say NON_POSIX_SOURCE to get the resulting .hc
3 -- to compile on sparc-solaris. Blargh.
5 -- -----------------------------------------------------------------------------
6 -- $Id: Time.hsc,v 1.12 2001/04/25 14:36:48 simonmar Exp $
8 -- (c) The University of Glasgow, 1995-2001
12 Haskell 98 Time of Day Library
13 ------------------------------
15 The Time library provides standard functionality for clock times,
16 including timezone information (i.e, the functionality of "time.h",
17 adapted to the Haskell environment), It follows RFC 1129 in its use of
18 Coordinated Universal Time (UTC).
20 2000/06/17 <michael.weber@post.rwth-aachen.de>:
22 * min./max. time diff currently is restricted to
23 [minBound::Int, maxBound::Int]
25 * surely other restrictions wrt. min/max bounds
31 `showTime' (used in `instance Show ClockTime') always prints time
32 converted to the local timezone (even if it is taken from
33 `(toClockTime . toUTCTime)'), whereas `calendarTimeToString'
34 honors the tzone & tz fields and prints UTC or whatever timezone
35 is stored inside CalendarTime.
37 Maybe `showTime' should be changed to use UTC, since it would
38 better correspond to the actual representation of `ClockTime'
39 (can be done by replacing localtime(3) by gmtime(3)).
43 * add proper handling of microsecs, currently, they're mostly
46 * `formatFOO' case of `%s' is currently broken...
50 * check for unusual date cases, like 1970/1/1 00:00h, and conversions
51 between different timezone's etc.
53 * check, what needs to be in the IO monad, the current situation
54 seems to be a bit inconsistent to me
56 * check whether `isDst = -1' works as expected on other arch's
59 * add functions to parse strings to `CalendarTime' (some day...)
61 * implement padding capabilities ("%_", "%-") in `formatFOO'
63 * add rfc822 timezone (+0200 is CEST) representation ("%z") in `formatFOO'
71 , ClockTime(..) -- non-standard, lib. report gives this as abstract
73 -- instance Show (non-standard)
78 , noTimeDiff -- non-standard (but useful when constructing TimeDiff vals.)
82 , normalizeTimeDiff -- non-standard
83 , timeDiffToString -- non-standard
84 , formatTimeDiff -- non-standard
90 , calendarTimeToString
97 #if defined(HAVE_GETTIMEOFDAY)
98 # ifdef HAVE_SYS_TIME_H
99 # include <sys/time.h>
101 #elif defined(HAVE_GETCLOCK)
102 # ifdef HAVE_SYS_TIMERS_H
104 # include <sys/timers.h>
108 #if defined(HAVE_TIME_H)
112 #ifdef HAVE_SYS_TYPES_H
113 #include <sys/types.h>
116 #ifdef HAVE_SYS_TIMEB_H
117 #include <sys/timeb.h>
120 #ifdef HAVE_WINDOWS_H
127 import PrelMarshalAlloc
128 import PrelMarshalUtils
129 import PrelMarshalError
142 -- One way to partition and give name to chunks of a year and a week:
145 = January | February | March | April
146 | May | June | July | August
147 | September | October | November | December
148 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
151 = Sunday | Monday | Tuesday | Wednesday
152 | Thursday | Friday | Saturday
153 deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)
155 -- @ClockTime@ is an abstract type, used for the internal clock time.
156 -- Clock times may be compared, converted to strings, or converted to an
157 -- external calendar time @CalendarTime@.
159 data ClockTime = TOD Integer -- Seconds since 00:00:00 on 1 Jan 1970
160 Integer -- Picoseconds with the specified second
163 -- When a ClockTime is shown, it is converted to a CalendarTime in the current
164 -- timezone and then printed. FIXME: This is arguably wrong, since we can't
165 -- get the current timezone without being in the IO monad.
167 instance Show ClockTime where
168 showsPrec _ t = showString (calendarTimeToString
169 (unsafePerformIO (toCalendarTime t)))
170 showList = showList__ (showsPrec 0)
173 @CalendarTime@ is a user-readable and manipulable
174 representation of the internal $ClockTime$ type. The
175 numeric fields have the following ranges.
181 year -maxInt .. maxInt [Pre-Gregorian dates are inaccurate]
182 mon 0 .. 11 [Jan = 0, Dec = 11]
186 sec 0 .. 61 [Allows for two leap seconds]
187 picosec 0 .. (10^12)-1 [This could be over-precise?]
188 wday 0 .. 6 [Sunday = 0, Saturday = 6]
189 yday 0 .. 365 [364 in non-Leap years]
190 tz -43200 .. 43200 [Variation from UTC in seconds]
193 The {\em tzname} field is the name of the time zone. The {\em isdst}
194 field indicates whether Daylight Savings Time would be in effect.
205 ctPicosec :: Integer,
212 deriving (Eq,Ord,Read,Show)
214 -- The @TimeDiff@ type records the difference between two clock times in
215 -- a user-readable way.
225 tdPicosec :: Integer -- not standard
227 deriving (Eq,Ord,Read,Show)
229 noTimeDiff :: TimeDiff
230 noTimeDiff = TimeDiff 0 0 0 0 0 0 0
232 -- -----------------------------------------------------------------------------
233 -- getClockTime returns the current time in its internal representation.
235 #if HAVE_GETTIMEOFDAY
237 allocaBytes (#const sizeof(struct timeval)) $ \ p_timeval -> do
238 throwErrnoIfMinus1_ "getClockTime" $ gettimeofday p_timeval nullPtr
239 sec <- (#peek struct timeval,tv_sec) p_timeval :: IO CLong
240 usec <- (#peek struct timeval,tv_usec) p_timeval :: IO CLong
241 return (TOD (fromIntegral sec) ((fromIntegral usec) * 1000))
245 allocaBytes (#const sizeof(struct timeb)) $ \ p_timeb -> do
247 sec <- (#peek struct timeb,time) p_timeb :: IO CTime
248 msec <- (#peek struct timeb,millitm) p_timeb :: IO CUShort
249 return (TOD (fromIntegral sec) (fromIntegral msec * 1000{-ToDo: correct???-}))
251 #else /* use POSIX time() */
253 secs <- time nullPtr -- can't fail, according to POSIX
254 return (TOD (fromIntegral secs) 0)
258 -- -----------------------------------------------------------------------------
259 -- addToClockTime d t adds a time difference d and a
260 -- clock time t to yield a new clock time. The difference d
261 -- may be either positive or negative. diffClockTimes t1 t2 returns
262 -- the difference between two clock times t1 and t2 as a TimeDiff.
264 addToClockTime :: TimeDiff -> ClockTime -> ClockTime
265 addToClockTime (TimeDiff year mon day hour min sec psec)
268 sec_diff = toInteger sec +
270 3600 * toInteger hour +
271 24 * 3600 * toInteger day
272 cal = toUTCTime (TOD (c_sec + sec_diff) (c_psec + psec))
274 new_mon = fromEnum (ctMonth cal) + r_mon
276 | new_mon < 0 = (toEnum (12 + new_mon), (-1))
277 | new_mon > 11 = (toEnum (new_mon `mod` 12), 1)
278 | otherwise = (toEnum new_mon, 0)
280 (r_yr, r_mon) = mon `quotRem` 12
282 year' = ctYear cal + year + r_yr + yr_diff
284 toClockTime cal{ctMonth=month', ctYear=year'}
286 diffClockTimes :: ClockTime -> ClockTime -> TimeDiff
287 -- diffClockTimes is meant to be the dual to `addToClockTime'.
288 -- If you want to have the TimeDiff properly splitted, use
289 -- `normalizeTimeDiff' on this function's result
291 -- CAVEAT: see comment of normalizeTimeDiff
292 diffClockTimes (TOD sa pa) (TOD sb pb) =
293 noTimeDiff{ tdSec = fromIntegral (sa - sb)
294 -- FIXME: can handle just 68 years...
295 , tdPicosec = pa - pb
299 normalizeTimeDiff :: TimeDiff -> TimeDiff
300 -- FIXME: handle psecs properly
301 -- FIXME: ?should be called by formatTimeDiff automagically?
303 -- when applied to something coming out of `diffClockTimes', you loose
304 -- the duality to `addToClockTime', since a year does not always have
307 -- apply this function as late as possible to prevent those "rounding"
309 normalizeTimeDiff td =
316 + 365 * tdYear td))))
318 (diffYears, rest1) = rest0 `quotRem` (365 * 24 * 3600)
319 (diffMonths, rest2) = rest1 `quotRem` (30 * 24 * 3600)
320 (diffDays, rest3) = rest2 `quotRem` (24 * 3600)
321 (diffHours, rest4) = rest3 `quotRem` 3600
322 (diffMins, diffSecs) = rest4 `quotRem` 60
324 td{ tdYear = diffYears
325 , tdMonth = diffMonths
332 -- -----------------------------------------------------------------------------
333 -- How do we deal with timezones on this architecture?
335 -- The POSIX way to do it is through the global variable tzname[].
336 -- But that's crap, so we do it The BSD Way if we can: namely use the
337 -- tm_zone and tm_gmtoff fields of struct tm, if they're available.
339 zone :: Ptr CTm -> IO (Ptr CChar)
340 gmtoff :: Ptr CTm -> IO CLong
342 zone x = (#peek struct tm,tm_zone) x
343 gmtoff x = (#peek struct tm,tm_gmtoff) x
345 #else /* ! HAVE_TM_ZONE */
346 # if HAVE_TZNAME || _WIN32
347 # if cygwin32_TARGET_OS
348 # define tzname _tzname
350 # ifndef mingw32_TARGET_OS
351 foreign label tzname :: Ptr (Ptr CChar)
353 foreign import "ghcTimezone" unsafe timezone :: Ptr CLong
354 foreign import "ghcTzname" unsafe tzname :: Ptr (Ptr CChar)
355 # def inline long *ghcTimezone(void) { return &_timezone; }
356 # def inline char **ghcTzname(void) { return _tzname; }
359 dst <- (#peek struct tm,tm_isdst) x
360 if dst then peekElemOff tzname 1 else peekElemOff tzname 0
361 # else /* ! HAVE_TZNAME */
362 -- We're in trouble. If you should end up here, please report this as a bug.
363 # error "Don't know how to get at timezone name on your OS."
364 # endif /* ! HAVE_TZNAME */
366 -- Get the offset in secs from UTC, if (struct tm) doesn't supply it. */
367 #if defined(mingw32_TARGET_OS) || defined(cygwin32_TARGET_OS)
368 #define timezone _timezone
372 foreign label altzone :: Ptr CTime
373 foreign label timezone :: Ptr CTime
375 dst <- (#peek struct tm,tm_isdst) x
376 tz <- if dst then peek altzone else peek timezone
377 return (fromIntegral tz)
378 # define GMTOFF(x) (((struct tm *)x)->tm_isdst ? altzone : timezone )
379 # else /* ! HAVE_ALTZONE */
380 -- Assume that DST offset is 1 hour ...
382 dst <- (#peek struct tm,tm_isdst) x
384 if dst then return (fromIntegral tz - 3600) else return tz
385 # endif /* ! HAVE_ALTZONE */
386 #endif /* ! HAVE_TM_ZONE */
388 -- -----------------------------------------------------------------------------
389 -- toCalendarTime t converts t to a local time, modified by
390 -- the current timezone and daylight savings time settings. toUTCTime
391 -- t converts t into UTC time. toClockTime l converts l into the
392 -- corresponding internal ClockTime. The wday, yday, tzname, and isdst fields
396 toCalendarTime :: ClockTime -> IO CalendarTime
397 toCalendarTime = clockToCalendarTime localtime False
399 toUTCTime :: ClockTime -> CalendarTime
400 toUTCTime = unsafePerformIO . clockToCalendarTime gmtime True
402 -- ToDo: should be made thread safe, because localtime uses static storage,
403 -- or use the localtime_r version.
404 clockToCalendarTime :: (Ptr CTime -> IO (Ptr CTm)) -> Bool -> ClockTime
406 clockToCalendarTime fun is_utc (TOD secs psec) = do
407 withObject (fromIntegral secs :: CTime) $ \ p_timer -> do
408 p_tm <- fun p_timer -- can't fail, according to POSIX
409 sec <- (#peek struct tm,tm_sec ) p_tm :: IO CInt
410 min <- (#peek struct tm,tm_min ) p_tm :: IO CInt
411 hour <- (#peek struct tm,tm_hour ) p_tm :: IO CInt
412 mday <- (#peek struct tm,tm_mday ) p_tm :: IO CInt
413 mon <- (#peek struct tm,tm_mon ) p_tm :: IO CInt
414 year <- (#peek struct tm,tm_year ) p_tm :: IO CInt
415 wday <- (#peek struct tm,tm_wday ) p_tm :: IO CInt
416 yday <- (#peek struct tm,tm_yday ) p_tm :: IO CInt
417 isdst <- (#peek struct tm,tm_isdst) p_tm :: IO CInt
421 tzname <- peekCString zone
423 let month | mon >= 0 && mon <= 11 = toEnum (fromIntegral mon)
424 | otherwise = error ("toCalendarTime: illegal month value: " ++ show mon)
427 (1900 + fromIntegral year)
434 (toEnum (fromIntegral wday))
436 (if is_utc then "UTC" else tzname)
437 (if is_utc then 0 else fromIntegral tz)
438 (if is_utc then False else isdst /= 0))
441 toClockTime :: CalendarTime -> ClockTime
442 toClockTime (CalendarTime year mon mday hour min sec psec
443 _wday _yday _tzname tz isdst) =
445 -- `isDst' causes the date to be wrong by one hour...
446 -- FIXME: check, whether this works on other arch's than Linux, too...
448 -- so we set it to (-1) (means `unknown') and let `mktime' determine
450 let isDst = -1 :: CInt in -- if isdst then (1::Int) else 0
452 if psec < 0 || psec > 999999999999 then
453 error "Time.toClockTime: picoseconds out of range"
454 else if tz < -43200 || tz > 43200 then
455 error "Time.toClockTime: timezone offset out of range"
458 allocaBytes (#const sizeof(struct tm)) $ \ p_tm -> do
459 (#poke struct tm,tm_sec ) p_tm (fromIntegral sec :: CInt)
460 (#poke struct tm,tm_min ) p_tm (fromIntegral min :: CInt)
461 (#poke struct tm,tm_hour ) p_tm (fromIntegral hour :: CInt)
462 (#poke struct tm,tm_mday ) p_tm (fromIntegral mday :: CInt)
463 (#poke struct tm,tm_mon ) p_tm (fromIntegral (fromEnum mon) :: CInt)
464 (#poke struct tm,tm_year ) p_tm (fromIntegral year - 1900 :: CInt)
465 (#poke struct tm,tm_isdst) p_tm isDst
466 t <- throwIf (== -1) (\_ -> "Time.toClockTime: invalid input")
469 -- mktime expects its argument to be in the local timezone, but
470 -- toUTCTime makes UTC-encoded CalendarTime's ...
472 -- Since there is no any_tz_struct_tm-to-time_t conversion
473 -- function, we have to fake one... :-) If not in all, it works in
474 -- most cases (before, it was the other way round...)
476 -- Luckily, mktime tells us, what it *thinks* the timezone is, so,
477 -- to compensate, we add the timezone difference to mktime's
480 gmtoff <- gmtoff p_tm
481 let res = fromIntegral t - tz + fromIntegral gmtoff
482 return (TOD (fromIntegral res) 0)
484 -- -----------------------------------------------------------------------------
485 -- Converting time values to strings.
487 calendarTimeToString :: CalendarTime -> String
488 calendarTimeToString = formatCalendarTime defaultTimeLocale "%c"
490 formatCalendarTime :: TimeLocale -> String -> CalendarTime -> String
491 formatCalendarTime l fmt (CalendarTime year mon day hour min sec _
492 wday yday tzname _ _) =
494 where doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
495 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
496 doFmt ('%':c:cs) = decode c ++ doFmt cs
497 doFmt (c:cs) = c : doFmt cs
500 decode 'A' = fst (wDays l !! fromEnum wday) -- day of the week, full name
501 decode 'a' = snd (wDays l !! fromEnum wday) -- day of the week, abbrev.
502 decode 'B' = fst (months l !! fromEnum mon) -- month, full name
503 decode 'b' = snd (months l !! fromEnum mon) -- month, abbrev
504 decode 'h' = snd (months l !! fromEnum mon) -- ditto
505 decode 'C' = show2 (year `quot` 100) -- century
506 decode 'c' = doFmt (dateTimeFmt l) -- locale's data and time format.
507 decode 'D' = doFmt "%m/%d/%y"
508 decode 'd' = show2 day -- day of the month
509 decode 'e' = show2' day -- ditto, padded
510 decode 'H' = show2 hour -- hours, 24-hour clock, padded
511 decode 'I' = show2 (to12 hour) -- hours, 12-hour clock
512 decode 'j' = show3 yday -- day of the year
513 decode 'k' = show2' hour -- hours, 24-hour clock, no padding
514 decode 'l' = show2' (to12 hour) -- hours, 12-hour clock, no padding
515 decode 'M' = show2 min -- minutes
516 decode 'm' = show2 (fromEnum mon+1) -- numeric month
518 decode 'p' = (if hour < 12 then fst else snd) (amPm l) -- am or pm
519 decode 'R' = doFmt "%H:%M"
520 decode 'r' = doFmt (time12Fmt l)
521 decode 'T' = doFmt "%H:%M:%S"
523 decode 'S' = show2 sec -- seconds
524 decode 's' = show2 sec -- number of secs since Epoch. (ToDo.)
525 decode 'U' = show2 ((yday + 7 - fromEnum wday) `div` 7) -- week number, starting on Sunday.
526 decode 'u' = show (let n = fromEnum wday in -- numeric day of the week (1=Monday, 7=Sunday)
527 if n == 0 then 7 else n)
528 decode 'V' = -- week number (as per ISO-8601.)
529 let (week, days) = -- [yep, I've always wanted to be able to display that too.]
530 (yday + 7 - if fromEnum wday > 0 then
531 fromEnum wday - 1 else 6) `divMod` 7
532 in show2 (if days >= 4 then
534 else if week == 0 then 53 else week)
536 decode 'W' = -- week number, weeks starting on monday
537 show2 ((yday + 7 - if fromEnum wday > 0 then
538 fromEnum wday - 1 else 6) `div` 7)
539 decode 'w' = show (fromEnum wday) -- numeric day of the week, weeks starting on Sunday.
540 decode 'X' = doFmt (timeFmt l) -- locale's preferred way of printing time.
541 decode 'x' = doFmt (dateFmt l) -- locale's preferred way of printing dates.
542 decode 'Y' = show year -- year, including century.
543 decode 'y' = show2 (year `rem` 100) -- year, within century.
544 decode 'Z' = tzname -- timezone name
549 show2, show2', show3 :: Int -> String
550 show2 x = [intToDigit (x `quot` 10), intToDigit (x `rem` 10)]
552 show2' x = if x < 10 then [ ' ', intToDigit x] else show2 x
554 show3 x = intToDigit (x `quot` 100) : show2 (x `rem` 100)
557 to12 h = let h' = h `mod` 12 in if h' == 0 then 12 else h'
559 -- Useful extensions for formatting TimeDiffs.
561 timeDiffToString :: TimeDiff -> String
562 timeDiffToString = formatTimeDiff defaultTimeLocale "%c"
564 formatTimeDiff :: TimeLocale -> String -> TimeDiff -> String
565 formatTimeDiff l fmt td@(TimeDiff year month day hour min sec _)
569 doFmt ('%':'-':cs) = doFmt ('%':cs) -- padding not implemented
570 doFmt ('%':'_':cs) = doFmt ('%':cs) -- padding not implemented
571 doFmt ('%':c:cs) = decode c ++ doFmt cs
572 doFmt (c:cs) = c : doFmt cs
576 'B' -> fst (months l !! fromEnum month)
577 'b' -> snd (months l !! fromEnum month)
578 'h' -> snd (months l !! fromEnum month)
579 'c' -> defaultTimeDiffFmt td
580 'C' -> show2 (year `quot` 100)
581 'D' -> doFmt "%m/%d/%y"
585 'I' -> show2 (to12 hour)
587 'l' -> show2' (to12 hour)
589 'm' -> show2 (fromEnum month + 1)
591 'p' -> (if hour < 12 then fst else snd) (amPm l)
593 'r' -> doFmt (time12Fmt l)
594 'T' -> doFmt "%H:%M:%S"
597 's' -> show2 sec -- Implementation-dependent, sez the lib doc..
598 'X' -> doFmt (timeFmt l)
599 'x' -> doFmt (dateFmt l)
601 'y' -> show2 (year `rem` 100)
605 defaultTimeDiffFmt (TimeDiff year month day hour min sec _) =
606 foldr (\ (v,s) rest ->
608 then show v ++ ' ':(addS v s)
609 ++ if null rest then "" else ", "
613 (zip [year, month, day, hour, min, sec] (intervals l))
615 addS v s = if abs v == 1 then fst s else snd s
618 -- -----------------------------------------------------------------------------
619 -- Foreign time interface (POSIX)
621 type CTm = () -- struct tm
623 foreign import unsafe localtime :: Ptr CTime -> IO (Ptr CTm)
624 foreign import unsafe gmtime :: Ptr CTime -> IO (Ptr CTm)
625 foreign import unsafe mktime :: Ptr CTm -> IO CTime
626 foreign import unsafe time :: Ptr CTime -> IO CTime
628 #if HAVE_GETTIMEOFDAY
630 foreign import unsafe gettimeofday :: Ptr CTimeVal -> Ptr () -> IO CInt
635 #ifndef mingw32_TARGET_OS
636 foreign import unsafe ftime :: Ptr CTimeB -> IO CInt
638 foreign import unsafe ftime :: Ptr CTimeB -> IO ()